Research Projects

Abstract

The limited knowledge of the internal structure of hadrons is one of the main factors reducing the accuracy of theoretical predictions for precision measurements in high-energy physics. The upcoming Electron-Ion Collider (EIC), the only big collider facility for fundamental particle physics with operations scheduled to start before the end of Large Hadron Collider data-taking, aims in the tomographic imaging of the 3D structure of protons and nuclei to address this limitation. Since most of the Monte Carlo (MC) event generators, including the mainstream ones, rely on collinear factorization, i.e. neglect the 3D structure of hadrons, new theoretical concepts have to be created and novel computational methods have to be developed, implemented, and validated to exploit the potential of the EIC fully. With this well-timed research project, I aim to go significantly beyond the state-of-the-art and expand one of the three most common MC generators, SHERPA, to systematically include the 3D structure of hadrons in the theoretical description of particle collisions. This overriding goal will be achieved by embedding the full Transverse Momentum Dependent (TMD) factorization framework within the MC event generator. I propose constructing the first two-scale TMD parton shower (PS), evolving in energy scale ? and rapidity ?, consistent with the TMD evolution. If successful- it will constitute the first full TMD MC generator ready for use by the EIC community and beyond.

Researcher(s)

• Promoter: Van Mechelen Pierre
• Fellow: Lelek Aleksandra

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

Our celebrated discovery of the Higgs boson by the LHC experiments at CERN in 2012 completed the collection of elementary particles that build up matter around us. To confirm its central place in our understanding of particle physics, the interaction strength (or coupling) of the Higgs boson to all three families of quarks and leptons must be measured and compared to theoretical predictions. Using the proton collisions collected by the CMS experiment at the LHC, we have successfully contributed to the milestone measurements of this coupling to the heaviest family of quarks, i.e. the top and bottom quarks. The next step is to unlock the charm quark-Higgs coupling that was previously anticipated not to be within reach of the LHC experiments. We propose a coherent and innovative experimental programme at the LHC to enable a first glimpse of this coupling with the potential to result in a legacy measurement.

Researcher(s)

• Promoter: Van Mechelen Pierre

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

Exploring elementary particles and their interactions is an age-old endeavour of humanity. With the 27 km circumference Large Hadron Collider (LHC) at CERN and the monumental detectors around it, scientists from all over the world have access to the most advanced tools to continue this exploration. A major achievement was the experimental confirmation of the existence of the Higgs boson particle in 2012, some 50 years after it had been predicted by Robert Brout, François Englert, and Peter Higgs. Fundamental questions about the reality around us, however, remain, such as, e.g., the nature of dark matter, the matter-antimatter asymmetry, the weakness of gravity, and the unification of all forces. The Compact Muon Solenoid (CMS) detector, to which the Flemish particle physics groups contributed in the design, construction, maintenance, and operation since its conception in the 1990's, allows to investigate and test many theoretical ideas that are being proposed to answer these questions. This project is vital to pursue this participation so that our groups can collect and analyse "Run 3" data and prepare the CMS detector for the upgraded High-Luminosity LHC.

Researcher(s)

• Promoter: Van Mechelen Pierre

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

An accurate, precise knowledge of PDFs is a key input of analyses at hadron colliders, and simultaneously a crucial output of the measurements made. The issue of accurately determining the PDFs, and their errors, is thus critical to the physics goals of the LHC. However, the current PDFs are faced with challenges on multiple fronts. Experimentally, the greater data accuracy ensures increasing issues of dataset tensions and correlations, meanwhile as the number, complexity and precision of datasets grows so does the methodological challenge of understanding apparent inconsistencies, limiting the reduction in PDF errors. In addition, the reduction of experimental uncertainties necessitates, for the first time, the inclusion of theoretical uncertainties in the PDFs – a significant challenge. Such challenges will increase over the coming years and may limit future LHC physics analyses unless action is taken. The over-arching research objective of my proposal is tackle these issues head-on, in order to develop the next generation of world-leading MSHT PDFs - MSHT2025, of greater accuracy and precision than ever before. I will then study the impact of the PDFs across a variety of key experimental channels for LHC physics. At the same time I will also combine our world-leading collinear PDFs, with the cutting edge transverse momentum dependent PDF approach at Antwerp, representing the production of TMDPDFs in a simultaneous global fit for the first time, a major step forward.

Researcher(s)

• Promoter: Van Mechelen Pierre
• Co-promoter: Hautmann Francesco
• Fellow: Cridge Thomas

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

The ability to directly observe gravitational waves (GW) opens up a whole new window to study our universe and its fundamental laws of physics. Such GW are however extremely weak and to detect them we need very sensitive interferometers capable of measuring displacements 10000 times smaller than the size of a proton. With current generation detectors we can observe several GW per year, originating from the coalescence of compact binary star systems. But to fully exploit the potential of gravitational waves it is crucial to enhance the sensitivity of GW observatories with several orders of magnitude, especially at low frequencies. This requires the usage of new technologies such as different mirror materials, laser wavelengths, and cryogenic temperatures to minimise noise. These new concepts can be studied with ETpathfinder, a R&D infrastructure for testing and prototyping novel technologies for the Einstein Telescope: a future third generation ground based European GW observatory. The aim of this project is to contribute to the construction and development of ETpathfinder, which will be built in Maastricht.  In particular, the focus will be on the development of detector control systems that are crucial to monitor and steer ETPathfinder operations with a minimal noise level. More precisely, we will construct and further develop linear variable differential transformer (LVDT) position sensors in combination with voice coil (VC) actuators. These are extremely accurate and crucial to construct seismic attenuation systems for GW detectors. The first objective is to contribute to the construction of LVDT/VC systems for ETpathfinder Phase 1 using state of the art designs. Afterwards we will focus on the development of novel LVDT/VC designs for future detector implementations. Finally we will participate in the commissioning and operation of ETpathfinder Phase 1, and contribute to first detector performance measurements. The research conducted in this project will lead to significant contributions to the ETpathfinder experiment, and will consolidate our knowledge in LVDT/VC systems. It can furthermore lead to improved LVDT/VC designs suitable for future GW observatories.

Researcher(s)

• Promoter: Van Haevermaet Hans
• Fellow: Kukkadapu Kumar Akhil

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

The spectacular first direct detections of gravitational waves (GW) have opened up hitherto unexplored and extreme regions of the universe. To realize the rich discovery potential of GWs with laser interferometry will require new collaborations and initiatives at the interface of physics and engineering. With this Declaration of Intent our research groups join forces to put forward a coherent research program building on our strengths and centered around six challenges in GW science and engineering. Our objectives include novel precision testing of Einstein's theory of gravity near black holes and in the early universe, and key advancements on the extremely stringent requirements on the mirrors and their coatings in the interferometer cavities. This will forge a cohesive vibrant Flemish research community in this nascent field, firmly embedded in the global collaborations working towards future observatories, thereby fully integrating Flanders into this exhilarating adventure to unlock the dark side of our universe.

Researcher(s)

• Promoter: Van Remortel Nick
• Co-promoter: Van Haevermaet Hans

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

Gravitational waves were predicted by Albert Einstein, but first observations were only made a few years ago ad were acknowledged by the 2017 Nobel prize in physics. Gravitational waves are a totally new source of information to study the origin, content and evolution of our universe. To study gravitational waves in great detail, a new telescope will be built, the Einstein Telescope, embedded in a large international laboratory infrastructure with a total cost of order 2 Billion Euros. The Einstein Telescope project will likely participate in the EU ESFRI roadmap update of 2021. Its design study will be complete soon, and then a decision on the European host-site will be made. The border region between Belgium, The Netherlands and Germany is candidate host-site, together with Sardinia. A number of key technologies needed to realize the Einstein Telescope is currently not available, and require research and development efforts in the coming decade. We will develop several of these at the ETpathfinder R&D Field lab, which is a shared innovation center at which scientific and industrial partners will work together in the next two decades. We therefore construct a jointly funded and operated cleanroom lab in Maastricht, that encompasses an advanced cryogenic Michelson laser interferometer setup to test the jointly developed technologies in a representative setup.

Researcher(s)

• Promoter: Van Remortel Nick

Research team(s)

• Particle Physics Group

Project website

Project type(s)

• Research Project

Abstract

My project will primarily focus on the search for and the discovery of the astrophysical stochastic gravitational wave background (SGWB) using novel and state-of-the-art data analysis software. In the science run of O4 starting in December 2022 and running for a year, data analysis will be performed actively on strain data. After the science run, the year-long data is combined to increase our chances of finding a hint of the SGWB. Next to that, in this project, I will develop a tool which can help automatically identify spectral artefacts in the frequency domain of the Virgo data and link them to an environmental channel. This will significantly increase our ability to identify such artefacts, as well as understand their origin and possible mitigation actions. During and after O4 I will be at the EGO/Virgo site investigating possible noise sources while "noise hunting". In Italy, I will also contribute to magnetic injections into the Virgo detector where the coupling between magnetic fields and the mirrors is investigated. Next to that, I will also, for the first time, investigate the effects of the buildings on external magnetic signals in the Virgo interferometer. At the end of the project, I will contribute to upgrading the detection statistics and noise models such that a better noise sensitivity of the Virgo detector is achieved in preparation for the next science run O5. That will increase the odds of discovering the stochastic background in O5.

Researcher(s)

• Promoter: Van Remortel Nick
• Fellow: Lalleman Max

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

In this project, I want to address a crucial problem in modern particle physics, namely the quest for the proton's 3D structure. According to the well-established theory of Quantum Chromodynamics, this building block of all visible matter is a composite particle built from elementary partons: quarks and gluons. Many collider experiments can be successfully described in a simple one-dimensional picture where these partons move in the same direction as their parent proton. This picture fails, however, when experiments are sensitive to the internal motion or spin correlations of the partons, nor can it account for most of the proton's main properties such as its radius, mass, and spin. To answer such fundamental questions, the full 3D structure of the proton needs to be explored. This structure can be extracted from experiments and encoded into 'transverse momentum dependent parton distribution functions' (TMDs). In this project, I will apply the promising new 'Parton Branching' (PB) method to the study of spin polarized TMDs, which are still poorly known but are essential to solving the puzzles mentioned above. The PB approach was recently developed at the UAntwerp and in DESY, and proved already very successful in the description of unpolarized TMDs. This project is extremely timely since the study of TMDs is a driving force behind several proposed new experiments worldwide (in CERN, BNL, JLab,...), among which the recently approved Electron-Ion Collider (EIC).

Researcher(s)

• Promoter: Van Mechelen Pierre
• Co-promoter: Hautmann Francesco
• Fellow: Taels Pieter

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

Searches for phenomena beyond the Standard Model of particle physics require precision predictions of final states observed in high-energy particle collisions. One of the main sources of uncertainty in theoretical predictions originates from parton distribution functions, whose evolution is described by quantum chromodynamics. The "Parton Branching method", which was recently developed by the UAntwerp team and their collaborators, allows to improve upon the state-of-the-art approach based on collinear factorization by including the transverse degrees of freedom of partons inside hadrons. With this project, we propose to apply this method and obtain fits of transverse momentum dependent parton densities to deep inelastic scattering and Drell-Yan production data obtained at the HERA and LHC colliders. These new fits will incorporate color coherence through a dynamical soft gluon resolution scale and will use transverse momentum dependent splitting functions, ultimately leading to an increased precision of theoretical predictions.

Researcher(s)

• Promoter: Van Mechelen Pierre
• Fellow: Sadeghi Barzani Safura

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

We aim to kickstart new expertise in gravitational wave instrumentation at UAntwerpen by contributing to the construction and development of ETPathfinder, a prototype for the Einstein Telescope: a future third generation gravitational wave observatory. In particular, the focus will be on the development of detector control systems that are crucial to monitor and steer ETPathfinder operations with a minimal noise level. We will set up a test system to construct and further develop linear variable differential transformer (LVDT) position sensors. These are extremely accurate and necessary to construct seismic attenuation systems for gravitational wave detectors. The performed research and its output will enable us to play a key role in future gravitational wave instrumentation.

Researcher(s)

• Promoter: Van Haevermaet Hans

Research team(s)

• Particle Physics Group

Project website

Project type(s)

• Research Project

Abstract

The university of Antwerp lies, since April 2019, and in close collaboration with research institutes in Flanders and The Netherlands, at the origin of the ETpathfinder R&D Fieldlab. This shared research infrastructure will, after completion, contribute for several decades to the development of high technological components for gravitational wave astronomy. The ultimate goal is the realization of the Einstein Telescope, a 30km long, underground laser interferometer in the border region between Belgium, The Netherlands and Germany, to study the cosmos via gravitational waves. The university of Antwerp is strongly committed to the realization of the nearly 2 billion Euro infrastructure of the Einstein Telescope project, because we believe in its potential to make scientific breakthroughs through technological innovation. Although the ultimate goal is to answer fundamental questions about the origin and evolution of our cosmos, the industrial/technological aspect as technology driver is undeniable, which is confirmed by three independent international socio-economic impact studies. The ETpathfinder R&D project should be considered as a platform to develop specialized technology In our region and thus to strengthen our site-bid for the Einstein Telescope project. In order to closely involve local industry from the start, the ET pathfinder consortium is assisted by an industrial advisory board (IAR), including representatives of nearly 40 Flemish and Dutch companies, sector organizations and local stakeholders. Many of these are located in our own province and are active in the fields of public infrastructure and construction, tunneling, underground and soil research, vessel and machine construction, sensor technology and micro-electronics, ICT and machine learning and computer aided modelling. With this IOF co-financing, the university of Antwerp can dedicate extra means and personnel to acquire expertise in the control and steering aspects of a large laser interferometer and its corresponding ICT and electronics infrastructure. As such we can profile ourselves better in the global ET infrastructure project, in view of the development and construction of the necessary computing and control infrastructure for ET in Flanders.

Researcher(s)

• Promoter: Van Remortel Nick

Research team(s)

• Particle Physics Group

Project website

Project type(s)

• Research Project

Abstract

Precision measurements have a prominent position at the Large Hadron Collider (LHC) as well as in the new accelerators' physics program and they relay on accurate theoretical predictions. In this proposal, a new way of obtaining predictions, the Parton Branching (PB) method, is discussed. The method, based on transverse momentum dependent (TMD) factorization theorem, aims in applicability to exclusive collider observables in a wide kinematic range. The basic element of cross sections calculations are parton distribution functions (PDFs). In contrast to the widely used collinear approach, the PB does not neglect the 3-dimensional structure of proton: the TMD PDFs (TMDs) are determined thanks to exact kinematic calculation. In this project outline an extensive theory program is proposed to establish connection between the PB and other approaches and to push the PB accuracy from next-to-leading logarithmic approximation to next-to-next-to-leading. The possibility of including small x together with small qt resummation within one approach by using TMD splitting functions will be investigated. The outcome of the project will be a big step forward in a common understanding of the TMD factorization and resummation. The theory developments will result in the new TMDs fit procedure within xFitter package, improved by incorporating the Drell-Yan data. The new TMDs will be used to obtain precise predictions for the crucial DY precision measurements at Run III and High Luminosity LHC.

Researcher(s)

• Promoter: Van Mechelen Pierre
• Co-promoter: Hautmann Francesco
• Fellow: Lelek Aleksandra

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

During this sabbatical leave, I will work on the following work packages: - update technical skill related to the analysis of experimental particle physics data; - study advanced topics in theoretical particle physics (including standard-model (QCD) and beyond-the-standard-model optics (SUSY)); - develop ideas related to the analysis and interpretation of particle collisions at the LHC (such as the near-side ridge, jet analysis with CASTOR, ...).

Researcher(s)

• Promoter: Van Mechelen Pierre

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

During this sabbatical leave, I will work on the following work packages: - update technical skill related to the analysis of experimental particle physics data; - study advanced topics in theoretical particle physics (including standard-model (QCD) and beyond-the-standard-model optics (SUSY)); - develop ideas related to the analysis and interpretation of particle collisions at the LHC (such as the near-side ridge, jet analysis with CASTOR, …).

Researcher(s)

• Promoter: Van Mechelen Pierre

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

This project is aimed to expand the research activities of the elementary particle physics group in the domain of fundamental interactions towards a study of gravity. The strong coupling regimes of Einstein's theory of general relativity can now be probed by gravitational wave observatories, several of which are online in the world. We propose to join the VIRGO collaboration and exploit the VIRGO/LIGO gravitational wave data to search for the existence of stochastic gravitational waves, the gravitational wave analogy of the cosmic microwave background (CMB). In contrast to the CMB, which only gives us a view on the universe when it was 370 thousand years old, the primordial gravitational wave signals will allow us to study the universe at its birth, at the period of inflation. The search for stochastic gravitational waves will in the longer term require a network of observatories with increased strain sensitivity. A future 3rd generation gravitational wave observatory will enhance the sensitivity to these and other types of gravitational waves significantly. With this project we also start an instrumental R&D program to develop key components for this future observatory.

Researcher(s)

• Promoter: Van Remortel Nick
• Co-promoter: Van Mechelen Pierre

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

This project aims to search for new sources of gravitational waves following the detection and first direct observation in 2015. The sensitivity of the current generation of gravitational wave interferometers will gradually be increased so every 10 to 20 days a binary black hole coalesce will be observed. It becomes interesting to search for weak signals originating from weak or distant sources, such as the coalescence of remote binary black holes, or binary neutron stars. Apart from these sources, do there also exist gravitational waves from more exotic sources, such as cosmic strings or black holes of several solar masses. Is it possible to isolate the ripples in the space-time fabric coming from the Big Bang itself from the different sources of gravitational waves? The current gravitational wave interferometers in the United States of America and Europe will start a year-long observation run in the spring of 2019 to improve the current sensitivity be a factor of 10. Afterwards the interferometers will undergo several improvements to steadily increase the sensitivity, followed by new observation periods. This should allow us to measure the gravitational waves of weak astrophysical sources such as the coalescence of remote binary black holes and remote neutron stars.

Researcher(s)

• Promoter: Van Remortel Nick
• Fellow: Janssens Kamiel

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

With the Large Hadron Collider (LHC) experiment, the particle physics community is searching for new physics beyond the standard model (SM). For this, theoretical models have to be translated to measurable quantities, observables. Monte Carlo (MC) event generators are the computational tools that simulate the experimental processes that occur in the LHC to make predictions of observables. In this project, models for SM Z bosons and BSM (beyond the SM) Z' bosons will be used for high precision calculations with a new MC event generator that has to be constructed. This new generator will make use of the recently developed parton branching (PB) method for transverse momentum dependent parton distribution functions (TMDs) and will be made available as an analysis tool for experimental and phenomenological collaborations. The TMD formalism is well suited to study non-inclusive observables such as transverse momentum and correlations. The implementation of the PB method in a new event generator is one of the main challenges because the separate parts that form the generator should be combined in a consistent and correct manner. Another challenge is to calculate hard scattering matrix elements for Z and Z' production from benchmark models. With the implementation of these matrix elements in the generator, it is expected to achieve high precision calculations that can contribute to a more detailed search for BSM physics.

Researcher(s)

• Promoter: Van Mechelen Pierre
• Fellow: van Kampen Aron Mees

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

To unravel the most fundamental building blocks of matter and how they interact to form the universe around us, is a longterm fascination and challenge of humanity. Participation in the CMS experiment at the LHC particle collider at CERN provides access to the forefront of this international research. With our recent discovery of the Higgs particle, all elementary particles of the Standard Model of particle physics are now observed. We started a unique exploration of how the Higgs particle fits into the model and our experimental verification of the predictability of the model is unprecedented. The omnipresence of dark matter in the universe is only one of the open questions in particle physics for which we seek answers typically by extending the Standard Model with new particles and interactions. Many phenomena related to these extensions can be discovered or tested with our experiment. The scientific ambition of the CMS Collaboration is perfectly aligned with the European Strategy for Particle Physics where the exploration with the LHC and soon its upgraded version is indicated as the highest priority for the field.

Researcher(s)

• Promoter: Van Mechelen Pierre
• Co-promoter: Van Remortel Nick

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

The detection of gravitational waves (GW) in 2015 and the beginning of the multi-messenger astronomy era have demonstrated the scientific potential of gravitational wave observatories and provide a solid basis for the future of GW (astro-)physics. Einstein Telescope (ET) is envisioned to be the pioneer of a new generation of gravitational wave detectors. An EU-funded ET Conceptual Design Study has identified the Belgian-Dutch-German border border area as a promising location to site Einstein Telescope. With this application we encourage our region, and Belgium, to fully support the ET proposal for the 2020 update of the ESFRI Roadmap. We also call for a concerted effort to establish our region as an international hotspot in GW research and to work together to realise this truly unique opportunity for Belgium to co-host a major international research facility.

Researcher(s)

• Promoter: Van Remortel Nick

Research team(s)

• Particle Physics Group

Project website

Project type(s)

• Research Project

Abstract

Gravitational waves provide a window for physicists to study the cosmos in a totally new way an over a wide range of aspecs: from black holes to the big bang itself. The study of gravitational waves requires a new large research infrastructure: The Einstein Telescope. It is a 3rd generation Michelson Interferometer telescope for gravitational waves and will be constructed at ~200m depth. The key enabling technologies for the Einstein Telescope are not yet complete and require extensive R&D. With the ETpathfinder R&D Fieldlab we aim to develop and test most of these technologies. ETpathfinder will be a distributed innovation centre where science and industry collaborate during a period of at least 2 decades.

Researcher(s)

• Promoter: Van Remortel Nick

Research team(s)

• Particle Physics Group

Project website

Project type(s)

• Research Project

Abstract

In 2012, a scalar particle has been discovered at the LHC (CERN). As of today, its properties match those of the Higgs boson of the Standard Model (SM), the current theory of fundamental interactions. This discovery has crowned 50 years of research, including seminal work done in Belgium by Brout and Englert. It has also opened a new era for particle physicists, with more-than-ever pressing mysteries to face, including the absence, despite predictions and indirect indications, of signs of new physics at the LHC. The overarching objective of this project, lead by a collaboration of theorists and experimentalists, is to use the Higgs as a probe of still largely unexplored territories beyond the SM. First, we aim at more precisely determining the Higgs boson couplings within the SM, including its self-coupling. We will either discover new interactions, or will constrain the range of possibilities. Concurrently, we will look for new scalar particles, possible siblings of the Higgs boson, a challenging and far-reaching task. Second, we will focus on a special feature of the Higgs boson, that of providing a gateway to a whole new world of hidden particles and interactions, an exploration which may shed light on the dark matter and neutrino mysteries. The proposal brings together the young generation of physicists that has contributed to the discovery of the Higgs and now leads a broad, ambitious and original research project on the high-energy physics frontier.

Researcher(s)

• Promoter: Van Remortel Nick
• Co-promoter: Van Mechelen Pierre

Research team(s)

• Particle Physics Group

Project website

Project type(s)

• Research Project

Abstract

This research proposal focuses on the new kinematic region of highly energetic, nearly back-to-back jets which will be explored for the first time at the LHC Run II. Our approach is based on recognizing that in the back-to-back region theoretical predictions for jet distributions are sensitive, despite the large transverse momentum of each individual jet, to Quantum Chromodynamics (QCD) colorcorrelation effects which go beyond the expectation of customary next-to-leading-order or next-tonext- to-leading-order calculations, and lead to novel "color entanglement" processes. We will employ advanced QCD factorization and resummation techniques to investigate these effects theoretically, to identify relevant jet observables, and to interpret the results of measurements of multi-TeV, nearly back-to-back jets which we will perform with the CMS detector at Run II. Phenomenological and experimental studies will focus on the jet transverse momentum imbalance, on the azimuthal distance between the jets, and on the azimuthal correlation between the leading jet transverse momentum and the transverse momentum imbalance. The outcome of the proposed studies will be a high-impact set of methods to deal with QCD color correlations in multi-jet final states, which could be used both for precision physics, possibly revealing new aspects of the Standard Model, and for searches for physics beyond the Standard Model in multi-jets channels, both at the LHC and future high-luminosity experiments.

Researcher(s)

• Promoter: Van Mechelen Pierre
• Co-promoter: Hautmann Francesco
• Co-promoter: Van Haevermaet Hans
• Co-promoter: Van Remortel Nick

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

The neutrino oscillation experiments, together with cosmological constraints and direct neutrino measurement experiments, have firmly established that at least 2 of the neutrinos have a tiny but non-vanishing mass. This provides tantalizing experimental evidence for physics beyond the standard model. "Sterile" neutrinos, introduced in several simple extensions of the Standard Model, provide an alluring way to explain these observations, through the so-called "seesaw" mechanism. Such sterile neutrinos interact with our known world only through their mixing with the SM neutrinos. Depending on the number of these additional sterile neutrinos and their masses, several outstanding questions in the field can also be addressed eg. a few-keV sterile neutrino can serve as a dark matter candidate; CP violation associated to these sterile neutrinos can be introduced to solve the observed matter-antimatter asymmetry of the universe; and several historical experimental anomalies can be explained. We propose to search for heavy sterile neutrinos by using the newly constructed SoLid detector near the BR2 reactor of the SCK-CEN in Mol. The detector is unique in its kind and is among several newly staged short baseline reactor experiments. The data analysis proposed here extends the baseline research program of the SoLid experiments to a vastly different mass scale of sterile neutrinos. SoLid is well placed for the detection of these states in comparison with older experiments due to the excellent background conditions near the BR2 reactor and the superior instrumentation and analysis techniques employed.

Researcher(s)

• Promoter: Van Remortel Nick
• Fellow: Verstraeten Maja

Research team(s)

• Particle Physics Group

Project website

Project type(s)

• Research Project

Abstract

The general purpose of this project is to implement methods of calculation and algorithms for inclusion of "true cascade summing" corrections into spectrum analysis software. This development should include design and validation of TCS correction algorithms, creation of nuclide libraries (if applicable) and/or implementation of calibration methods. All results must be included into software for Gamma-ray spectrum analysis – bGAMMA. Objectives: 1) Study current implementations (published) and calculation algorithms for TCS correction in Gamma-ray spectrometry 2) Identify the applications and corresponding list of nuclides (of interest) and their type of TCS correction, according to specific decay scheme. For some cases adoption of restrictions and/or simplifications might be applicable. As result radioisotope libraries containing the TCS correction factors for specific applications should be created 3) Developed a (if possible) generic algorithm for calculation of TCS in gamma-ray spectrometry. If necessary, particular or complete nuclide libraries must be created as well. 4) Implementation of validation tests, experimental measurements and mathematical Monte Carlo simulations for different applications, nuclides of interest, sample geometries and densities and detectors efficiencies. 5) Implementation of a calibration method using "Peak-to-Total" detector efficiencies or "LS" calibration curves to derive the TCS corrections. 6) Implementation of proposed algorithm(s) and specific TCS-aware nuclide libraries for TCS corrections into the general purpose gamma-ray spectrum analysis software- bGAMMA

Researcher(s)

• Promoter: Van Remortel Nick
• Fellow: Piñera Ibrahin

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

Our current understanding of the most elementary building blocks of matter and their interactions is summarized in the Standard Model of particle physics. Within this Standard Model, neutrinos are the most puzzling. Decades of experiments have lead to the conclusion that neutrinos have a very small mass. Due to this small mass, a neutrino of a certain flavor has a non-zero probability to oscillate to a neutrino of another flavor. Oscillations between the three neutrinos in the Standard Model have been observed typically over large distances (>1km) from the place where they were produced. Over the last years, a deficit of the observed number of neutrinos at short distances (<100m) from reactors is measured. This could be an indication of an oscillation to a fourth and new type of neutrino. The aim of recent short baseline neutrino experiments is to prove or discard the hypothesis of the existence of the so-called sterile neutrino. One of the most promising short baseline experiments that is able to answer this question is the SoLid experiment. The SoLid detector is a neutrino detector consisting of plastic scintillator cubes with Li-6 screens installed at a the BR2 reactor at SCK-CEN in Mol, Belgium. The detector setup has been tested thoroughly over the last years and a 5 times larger detector is currently being constructed. This project aims to record and analyze the new data in order to provide an answer to the sterile neutrino hypothesis in the next 4 years.

Researcher(s)

• Promoter: Van Remortel Nick
• Co-promoter: De Roeck Albert

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

The main objective of the project is to perform a thorough study of QCD by conducting precise and novel measurements with the CMS experiment at the LHC using the new RunII data with a centre- of-mass energy of vs = 13 TeV. We want to focus on the experimental measurements of processes that challenge the mainstream collinear factorisation approach that is complemented with phenomenological models. In particular the study of final state jet correlations yields an excellent sensitivity to the physics of interest. The outcome of these measurements is a direct input for the theory community and provides feedback to the phenomenological groups that develop Monte Carlo event generator models. The goal is to actively contribute to an innovation of the research field, by proposing and studying new observables or analysis techniques that can lead to reduced systematic uncertainties or sensitivity to new dynamical effects in QCD. In addition, conventional studies of QCD are performed with low luminosity data that will become less common at high luminosity hadron colliders like the LHC, the last part of the project therefore aims to investigate the feasibility of future QCD measurements in high pile-up conditions.

Researcher(s)

• Promoter: Van Mechelen Pierre
• Fellow: Van Haevermaet Hans

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

Scientific curiosity drives us to explore the largest as well as the smallest structures around us. With its 27 km circumference the Large Hadron Collider at CERN collides protons at the highest energies to study the most fundamental building blocks of matter. The recent discovery of the Higgs particle by the ATLAS and CMS experiments was awarded internationally. As a consequence the particle physics community worldwide assigns the top priority to further explore the properties of the Higgs particle as well as to extend our search for new physics phenomena. From 2026 onwards the High-Luminosity LHC will be operational at CERN delivering a 10 times larger dataset of proton collisions to the physicists. This requires the construction of adequate and typically novel detector systems. The Belgian experimental particle physics groups are skilled and motivated to continue their research and leadership in the CMS experiment. The Tracker System is the main system to be innovated and replaced. This Hercules application embraces the construction by the Belgian teams of one Tracker Endcap. This exceptional equipment will be the basis of our research for the next 2 decades.

Researcher(s)

• Promoter: Van Mechelen Pierre
• Co-promoter: Van Remortel Nick

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

With the discovery of the Higgs boson at the Large Hadron Collider (LHC) at CERN, announced in July 2012, decades of searches for this cornerstone of the Standard Model (SM) of particle physics concluded with a triumph of science. Despite its remarkable success in describing the experimental data so far, there exist compelling reasons to expect new physics to extend the SM. One of the most studied extensions is Supersymmetry (SUSY). This theory addresses several of the fundamental open questions in the field through the prediction of so-far unobserved new particles. The LHC provides a unique place to search for SUSY at energies never reached before in a laboratory. The LHC will restart colliding protons in Spring 2015 at nearly doubled energy and with higher rates. With a Higgs boson already discovered, searching for new physics, in particular SUSY, is now the top priority of the LHC experiments. The Flemish institutes participating in the CMS experiment propose a research project comprising of a suite of coherent and complementary analyses with the goal to discover or rule out so-called natural SUSY. In either case, the results will have direct impact on the future direction of the field. In case of no discovery, SUSY will lose its long-standing appeal as an extension of the SM. In case of discovery, a new chapter opens for particle physics and our fundamental understanding of space, time, and matter, with possible far-reaching consequences on other research fields.

Researcher(s)

• Promoter: Van Mechelen Pierre
• Co-promoter: Janssen Tahys

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

Cosmoparticle physics is a fundamental discipline that emerged at the end of the 20th century, and it is a quickly evolving field. It studies the relationship between the largest scales of the Universe and the smallest scales in Nature. As such, it is at present a multi-disciplinary field interconnecting particle physics, cosmology, general relativity, astrophysics and astrophysics This network aims to bundle the expertise in various fields related to cosmoparticle physics in Belgium through interchange of researchers, common meetings and seminars and contacts with international centers of expertise.

Researcher(s)

• Promoter: Van Remortel Nick

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

With this project the universities of Antwerpen, Gent and Brussels, and the SCK-CEN Mol intend to construct a competitive short baseline reactor neutrino detector at the BR2 research reactor with a thermal power between 60-80MW located at the SCK-CEN in Mol.

Researcher(s)

• Promoter: Van Remortel Nick
• Co-promoter: De Roeck Albert

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

The main focus of the present project will be on hadrons, the particles subject to the strong force. Among them, special attention is devoted to nucleons (protons and neutrons), which are the building blocks of atomic nuclei, the predominant constituents of matter.

Researcher(s)

• Promoter: Van Mechelen Pierre
• Fellow: Pisano Cristian

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

The search for sterile neutrinos is a next step in the fundamental research of elementary particles and their interactions. With SoLid, we created a new international collaboration of 11 research centers spread across Europe and the United States. Together we develop and exploit a novel neutrino detector near the core of the BR2 research reactor of the SCK-CEN in Mol. With this instrument we aim to study short-baseline neutrino oscillations, a phenomenon that can reveal new physics in the neutrino sector and perhaps an indication of the nature of dark matter.

Researcher(s)

• Promoter: Van Remortel Nick

Research team(s)

• Particle Physics Group

Project website

Project type(s)

• Research Project

Abstract

Due to the large parton density in proton-proton collisions at the LHC, the probability of having more than one parton interaction per event is non-negligible. In particular, double parton scattering (DPS), an interaction where each proton has two active partons giving rise to two different subprocesses, is relevant. These additional interactions may reach a hard scale comparable to the primary scattering and become experimentally distinguishable at high energies. In an interaction with DPS, pairs of jets are expected to exhibit specific angular and momentum distributions that reflect the peculiar correlation of the pairs. My research project is related to the measurement, performed with the CMS experiment at the LHC, of discriminating observables for a direct DPS detection in a four-jet scenario. This channel, considered a benchmark for a DPS evidence due to the high statistics that can be achieved, opens wide regions of the phase space where the DPS signal is dominant with respect to background events arising from single chain processes. The final goal is the extraction of the physical quantity "sigma effective" related to the internal structure of the proton. This necessarily implies the definition of templates for signal and background at Monte Carlo level, where different solutions and models can be tested and an universal choice for them can be established. A reliable and pure definition of the templates will be then used by all the other DPS analyses.

Researcher(s)

• Promoter: Van Mechelen Pierre

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

From our long standing experience in tracking devices, we wish to take an active role in the development of a new Silicon Strip Tracking system as well as an upgraded Muon System for CMS. Our R&D related to the Muon System is targeted at the LS2 upgrades, while the Silicon Tracker part will have its main impact in the later stages of CMS.

Researcher(s)

• Promoter: Van Remortel Nick

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

The main objective of the project is to perform a thorough study of QCD by conducting precise and novel measurements with the CMS experiment at the LHC. With this project we want to focus on the experimental measurements of processes that challenge the mainstream collinear, single parton exchange approach. The outcome of these measurements is a direct input for the theory community and provides feedback to the phenomenological groups that develop various MC model implementations.

Researcher(s)

• Promoter: Van Mechelen Pierre
• Fellow: Van Haevermaet Hans

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

The search for a scalar Higgs particle is one of the main goals of the physics program of the Large Hadron Collider at CERN. Using the data collected by the Compact Muon Solenoid (CMS) experiment we plan to implement and validate a matrix element technique to search for a light neutral scalar Higgs boson. Matrix element techniques incorporate the maximum theoretical knowledge about signal and background processes in order to infer a physical quantity from data. This method will extend the sensitivity of cut-based and multivariate analysis techniques already applied in CMS and will contribute to the discovery or exclusion of Higgs particles within or beyond the Standard Model of particle physics.

Researcher(s)

• Promoter: Van Remortel Nick
• Fellow: Alderweireldt Sara

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

With this grant we want to perform the experimental measurement of processes that challenge the mainstream collinear, single parton exchange approach. We propose measurements that can be covered within the limited time frame of the grant, but which are part of a longer term program: the systematic exploration of multi-jet final states at low transverse momentum (pT). This is innovative research since it has never been done at the LHC in the proposed kinematic region. With the first round of LHC data fully available and new theoretical developments allowing to create a scheme to overcome approximations used so far, the time is right for a dedicated effort to fully explore the potential in theory and experiment.

Researcher(s)

• Promoter: Van Mechelen Pierre
• Fellow: Knutsson Albert

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

There is a common interest to extend collaboration in order to investigate the following phenomena: - The existence and nature of double hard parton scatterings - Their theoretical description and modelling in terms of parton density distributions and evolution equations - The impact of this phenomenon on searches for new particles predicted by supersymmetric extensions of the Standard Model of particIe physics.

Researcher(s)

• Promoter: Van Remortel Nick

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

The quest to explore and understand the fundamental building blocks of Nature has intrigued humanity since ever. Revealing the way they build up the matter around us as well as the Universe is the topic of particle physics. Our state-of-the-art theory in particle physics does not provide an empirically verified answer to key questions like how these particles acquire their observed mass nor for the abundance of Dark Matter in the Universe. Experiments are being built to unravel these elements by discovering new physics phenomena beyond our current theory and to measure very precisely the properties of the known phenomena. The Large Hadron Collider at CERN is the unique particle accelerator which is at the forefront of this research by colliding protons at the highest energies. The Compact Muon Solenoid experiment is built and operated by an international consortium of institutions to detect and reconstruct the particle collisions. The Universiteit Antwerpen, the Universiteit Gent and the Vrije Universiteit Brussel have very active teams of researchers that construct, operate and maintain the experiment as well as analysing the accumulated data of the CMS detector in the search for an understanding of the fundamental interactions in Nature. This project embraces all the detector, logistical and operational costs for the Flemish contribution to one of the largest scientific experiments ever.

Researcher(s)

• Promoter: Van Mechelen Pierre
• Co-promoter: Van Remortel Nick

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

The objective of this project is to obtain a clear insight into the nature of the Higgs mechanism, in particular whether it is associated with a single scalar boson, with multiple scalars, a composite object of strongly bound fermions, or with heavier resonances. This will be done by performing measurements in the years 2012-2020 at the Large hadron Collider (LHC), a protonproton collider located at the CERN laboratory for particle physics in Geneva, operating at the highest beam energies ever achieved.

Researcher(s)

• Promoter: Van Remortel Nick
• Co-promoter: Van Mechelen Pierre

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

The application domain of embedded systems is in need of design processes for parallel data processing in FPGAs. This project will develop a concrete design process based on a case study of simple pattern recognition by means of a high-level synthesis tool. This will lead to new generic insights in the design process of FPGA-code, as well as the efficient development of algorithms being used in current particle physics experiments.

Researcher(s)

• Promoter: Van Remortel Nick
• Co-promoter: De Meulenaere Paul

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

Fundamental interactions include electroweak forces, strong interactions, and gravity (and their possible extensions). Their study aims at unraveling Nature's mechanisms at their most intimate level, but should also provide understanding of our Universe and its evolution through work at the edge of present knowledge. The ultimate purpose of the project is to improve our understanding of fundamental interactions.

Researcher(s)

• Promoter: Van Remortel Nick

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

The primary objective of this project is to analyze the data that will be collected by the CMS experiment in 2012 to provide a further independent confirmation of the existence of a light Higgs boson using a topology that has not been studied so far: the Higgs production through vector boson fusion (VBF) and it's decay to b-quarks. The final state is a distinctively full hadronic topology, with four hadronic jets, which makes it a both an unconventional and challenging search. The results will provide access to the Yukawa Higgs couplings to b-quarks and to weak vector bosons (W,Z), improving our understanding of the electroweak symmetry breaking mechanism.

Researcher(s)

• Promoter: Van Mechelen Pierre
• Co-promoter: Van Remortel Nick
• Fellow: Azzurri Paolo

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

The search for a scalar Higgs particle is one of the main goals of the physics program of the Large Hadron Collider at CERN. Using the data collected by the Compact Muon Solenoid (CMS) experiment we plan to implement and validate a matrix element technique to search for a light neutral scalar Higgs boson. Matrix element techniques incorporate the maximum theoretical knowledge about signal and background processes in order to infer a physical quantity from data. This method will extend the sensitivity of cut-based and multivariate analysis techniques already applied in CMS and will contribute to the discovery or exclusion of Higgs particles within or beyond the Standard Model of particle physics.

Researcher(s)

• Promoter: Van Remortel Nick
• Fellow: Alderweireldt Sara

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

The UA group aims to measure final states consisting of multiple jets in order to study QCD parton dynamics at low fractional momenta, multi-parton interactions and the underlying event.

Researcher(s)

• Promoter: Van Mechelen Pierre
• Co-promoter: Van Remortel Nick

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

TERA-Labs, a joint research group of the Karel De Grote Hogeschool specialised in Embedded Systems, datacommunication and ICT partners with the experimental Elementary Particle Physics group of the University of Antwerp in research of high performance distributed FPGA-based data acquisition systems based on µTCA, a promising new standard in embedded technology. The aim is to establish and expertise platform in the hardware-software co-design of complete data acquisition systems with pure scientific and industrial measurement and automisation applications.

Researcher(s)

• Promoter: Van Remortel Nick
• Co-principal investigator: Temmerman Marijn

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

We propose to study the heavy flavor content of the proton through the measurement of particle jets initiated by bottom quarks together with Z bosons in proton-proton collisions, using the CMS detector at the Large Hadron Collider. We will compare the obtained experimental results to theoretical predictions based on different factorization schemes in perturbative Quantum Chromodynamics.

Researcher(s)

• Promoter: Van Mechelen Pierre
• Co-promoter: Van Remortel Nick

Research team(s)

• Particle Physics Group

Project website

Project type(s)

• Research Project

Abstract

This is a fundamental research project financed by the Research Foundation - Flanders (FWO). The project was subsidized after selection by the FWO-expert panel.

Researcher(s)

• Promoter: Van Remortel Nick
• Co-promoter: Van Mechelen Pierre

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

The existence of gravitons, as predicted in the ADD (Arkani-Hamed-Dimopoulos-Dvali) model, is investigated using the jet+MET (Missing Transverse Energy) final state in proton-proton interactions at the LHC collider. Using the CMS detector and the Belgian GRID infrastructure the collision data characterized by the monojet signature are collected and analyzed: to this end the trigger and analysis algorithms are optimized based on the first data collected by the CMS detector and earlier work based on Monte Carlo simulations."

Researcher(s)

• Promoter: Van Mechelen Pierre
• Fellow: Maes Thomas

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

The Compact Muon Solenoid experiment has put emphasis on the detection and identification of muons; the only penetrating charged particle we know. At the LHC, the bunch crossing frequency will be 40 MHz, which, at the nominal luminosity of 10^34 cm-2s-1, leads to 800 million proton-proton collisions per second. Every 25 nsec some 1000 particles emerge from the interaction point into the CMS spectrometer. In less than 3 microsec a first level trigger has to reduce this rate to 100 kHz without losing potentially interesting collisions requiring further analysis. This task, without which research at the LHC would be impossible, relies heavily on the muon detection system. The construction of the forward muon RPC system for the CMS phase 1 detector is completed and consists of 432 chambers. All gas gaps have been produced and tested in Seoul where a gas gap production facility has been set up for this project. It is an alternative to the Italian company GT that up to then had the world monopoly for RPC gas gap production and delivered gaps to L3, Babar, ATLAS and the CMS barrel. Station 1 (144 RPC's) has been produced and tested at CERN with the help of Chinese manpower. Stations 2 and 3 (288 RPC's) are assembled in Islamabad and retested at CERN. For the final testing of endcap RPC's, a large area cosmic hodoscope has been built at CERN in which 10 chambers can be tested together. This infrastructure will remain operational until completion of the entire system. Today all 432 RPC detectors of the initial system have been installed on the endcap yokes. The completion of the forward RPC system for CMS phase 2 will require 288 extra chambers for the |eta|<1.6 region and 180 RPC's for the region 1.6 <eta< 2.1. Production of gas gaps will further proceed in Seoul while chamber assembly would be performed in the other participating institutes and possibly also in Belgium. The final testing of the detectors would be concentrated in the CERN cosmic hodoscope. As mentioned before the total cost for the completion of the CMS forward RPC system is estimated to be 6 MCHF and an equal sharing among the participants is envisaged resulting in 1MCHF for the Belgian partners. It is proposed that 160 RPC chambers would be assembled in Ghent and Brussels, while Antwerp will concentrate more on the front end read out electronics.

Researcher(s)

• Promoter: De Wolf Eddi
• Co-promoter: Van Remortel Nick

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

Recent precision measurements of the top quark and W-boson masses at the Tevatron collider, Fermilab, USA, imply the existence of a relatively light Higgs boson with a mass less than 144 GeV at 95% C.L. The search for a light to intermediate mass Higgs boson is now of top priority in the Tevatron physics program (recently extended until end 2009), and is one of the main motivations for the construction of the LHC collider at CERN, which begins its operations in the spring of 2008. For masses below 144 GeV, the Higgs decays with 98% probability to a pair of b-quarks, making its separation from background processes very difficult at the Tevatron. The increased centre-of-mass energy and luminosity of the LHC will overcome some of these problems by allowing more stringent selections and/or the study of rare decays and by opening a range of new Higgs production mechanisms that have smaller cross sections at the Tevatron. The latter will be used as main strategy in this proposal where a Higgs discovery group will systematically explore the Higgs boson mass range between 114-135 GeV, by using data collected by the CMS experiment at the LHC collider at CERN, Geneva, Switzerland. The project's focus is the distinct topology where the Higgs boson decays into a pair of b quarks and is accompanied by the production and decays of two top quarks: ttH->bbWWbb. We will investigate mainly the final states in which at least one W boson decays leptonically. The proposed research complements ongoing activities at the particle physics group of the University of Antwerpen, where a Higgs boson search at intermediate to High Higgs masses is conducted in the dominant decay mode H->WW, using final states in which both W's decay leptonically. Both projects combined will cover the whole Higgs mass region which is kinematically accessible by the LHC accelerator.

Researcher(s)

• Promoter: Van Remortel Nick
• Co-promoter: De Wolf Eddi

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

Using the CMS detctor at the LCH accelerator of the CERN laboratory we will study final states resulting from proton-proton collisions at unprecendented energies of 14 TeV. Certain final states, consisting of a collimated particle jet and lots of missing energy, are sensitive to new phenomena related to the production of gravitons that propagate in compactified spatial dimensions, which are being proposed as a possible solution to the hierachy problem in quantum-gravity.

Researcher(s)

• Promoter: Van Remortel Nick

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

The project is part of the FWO Big Science funding which allows participation in large-scale international experiments at CERN and elsewhere. The funding covers our participation to the CMS experiment at the LHC in CERN in terms of logistic personnel support, contributions to the 'Maintenance and Operation' of the CMS detector and the development of local GRID infrastructure..

Researcher(s)

• Promoter: De Wolf Eddi
• Promoter: Van Mechelen Pierre
• Co-promoter: Van Mechelen Pierre

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

The Standard Model of electroweak and strong interactions predicts the existence of an unique scalar particle, the Higgs boson, responsible for electroweak symmetry breaking and mass generation. In the year 2008, the Large Hadron Collider(LHC) will start to take data. The search for the Standard Model Higgs boson H in WW->2l2v decay mode represents one of the main discovery channels at the LHC and is proposed as research project.

Researcher(s)

• Promoter: Delmeire Evelyne

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

Fundamental interactions include electroweak forces, strong interactions, and gravity. Their study aims at unraveling Nature's mechanisms at their most intimate level, including the origin of the Universe, through work at the boundary of present knowledge. Such knowledge is sought trough tighter collaboration between all Belgian theorists and experimentalists active in the field of fundamental interactions.

Researcher(s)

• Promoter: De Wolf Eddi

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

The Large Hadron Collider, LHC, will start operating at CERN in 2007. The Particle Physics group of the University of Antwerp is a participant in the CMS experiment. Major physics goals are the understanding of the electroweak symmetry breaking, the search for signals of 'new physics' such as supersymmetry or large extra dimensions, and the study of Quantum Chromodynamics processes. The Forward Physics program, the subject of this proposal, aims at enhancing the capabilities of the CMS experiment for diffractive and forward physics. The project will concentrate on the use of forward proton detection as a unique means to discover new physics at the LHC.

Researcher(s)

• Promoter: De Wolf Eddi
• Promoter: Van Mechelen Pierre
• Co-promoter: De Roeck Albert
• Co-promoter: Van Mechelen Pierre

Research team(s)

• Particle Physics Group

Project website

Project type(s)

• Research Project

Abstract

This project aims to analyse the data that will collected by the CMS detector at the LHC accelerator. It consist mainly of the research of the top quark and so-called "diffraction and forward physics". To realise this a contribution will be made to the development of a Belgian TIER-2 GRID computing centre.

Researcher(s)

• Promoter: Van Mechelen Pierre
• Co-promoter: De Roeck Albert
• Co-promoter: De Wolf Eddi
• Co-promoter: Van Remortel Nick

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

The project aims to study very forward rapidity physics in pp interactions at a center-of-mass energy of 14 TeV (Tera-eV) with the CASTOR calorimeter, a sub-detector of the gigantic CMS detector at the LHC at CERN. The project involves generator-level Monte-Carlo studies of Drell-Yan production to estimate detection efficiencies, resolutions and possible backgrounds. In addition, software simulation modules, within the official CMS software environment, will be developed to simulate the detailed energy response of CASTOR.

Researcher(s)

• Promoter: Van Mechelen Pierre

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: De Wolf Eddi
• Co-promoter: Van Mechelen Pierre

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

Experimental research in particle physics with detectors at the HERA and LHC accelerators.

Researcher(s)

• Promoter: Van Mechelen Pierre
• Fellow: Van Mechelen Pierre

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

The primary objective of the project is the collection and analysis of data acquired from 2005 to 2007 with the H1 detector and the VFPS in order to study processes of the type e + p ¿ e p X, with jets or charmed particles in the final state. Diffractive dissociation in electron-proton collisions, in particular in association with final states containing jets or heavy quarks, can be described in Quantum Chromodynamics (QCD), the theory of the strong force. The phenomenon of diffraction is connected to fundamental properties of the strong force, including the confinement of quarks inside hadrons. The proposed measurements will provide novel information on the (diffractive) quark and gluon content of the photon and proton and further allow to test a variety of theoretical models and higher order QCD calculations. The project requires expertise on both the analysis of jets and of diffractive interactions, on the operation of the VFPS and on theoretical QCD calculations. In this respect the Prague and Antwerp groups are complementary and benefit both from a close collaboration. To achieve the project goals, regular exchanges between the institutes in Prague and Antwerp and the DESY laboratory in Hamburg are needed.

Researcher(s)

• Promoter: De Wolf Eddi

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: De Wolf Eddi

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

The CMS-CASTOR calorimeter measures energy depositions in proton-proton and heavy ion collisions produced by the LHC in the rapidity range between 5.2 and 6.6. It allows to measure the forward energy flow as well as the production of jets and rapidity gaps at forward rapidity. The physics motivation for building this detector includes the study of underlying event properties, QCD evolution and parton dynamics and diffraction. In the framework of this project, the CASTOR Monte Carlo simulation based on GEANT is validated using test beam data obtained in 2007, 2008 and 2009 using a prototype version of the detector. In addition the very first proton-proton collision data, collected in 2009 and 2010 is analyzed and the forward energy flow is measured and compared between minimum bias events and events with a hard scale set by a jet produced at central rapidity.

Researcher(s)

• Promoter: Van Mechelen Pierre

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: De Wolf Eddi
• Fellow: Tsurin Ilya

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

Micro Gap Counters are a new kind of detectors for charged particles. They have the following properties: high spatial resolution, large counting rate, radiation resistent. Different parameters of these detectors will be optimised and a large prototype build, consisting of some 70 elementary cells, 10 by 10 cm each.

Researcher(s)

• Promoter: De Wolf Eddi
• Co-promoter: Van Mechelen Pierre

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

The present proposal centers around the 'Very Forward Proton Spectrometer' (VFPS) project, a new detector to be commissioned this year for the H1 experiment at DESY in Hamburg. The Belgian groups, and the UIA in particular, have initiated and taken major responsabilities in this project. The goal of the project is to perform refined second-generation experimental studies of the phenomenon of diffractive dissociation in deep-inelastic electron/positron-proton collisions at the HERA collider.A primary objective is the analysis of the first data to be collected in 2004 with the VFPS. The focus will be on the study of diffractive jet production and charmed particle production with a directly tagged proton in the reaction positron + proton ? X + proton. Jet production and heavy quark production can be theoretically described in Quantumchromodynamics (QCD), the theory of the strong force. The measurements to be performed will provide novel information on the quark and gluon composition of the (virtual) photon and of the Pomeron and further allow to test a variety of theoretical models, in particular higher-order perturbative QCD calculations.Technically, the project requires i) implementation of the simulation- and reconstruction software of the VFPS system, ii) development of techniques to calibrate the detector in a true collision environment, in real-time. These tasks will be performed by the UIA group, with the help of software specialists from the Prague group.For the analysis of the data, leading to publications, the existing rich expertise of the Prague group in the study of jet production will be of essential value and complement the know-how of the Flemish partner.

Researcher(s)

• Promoter: De Wolf Eddi

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

Recently, the study of diffractive processes has known a large renewed interest. The diverse experimental programmes of current hadron accelerators such as HERA and TEVATRON offer, together with future machines such as the LHC at CERN, a great new challenge both in theoretical and experimental particle physics research. Diffractive processes can be considered as a sub-class of inelastic scattering processes, where one of the colliding particles survives the interaction: A + B à A + X. The H1 experiment of the German research centre DESY, situated in Hamburg, to which the particle physics group of the UA is connected, has seen a considerable upgrade last year. The very forward proton spectrometer (VFPS), co-developed by our group and partly financed by the FWO, is a considerable part of this upgrade. The VFPS detector is complementary to the existing system of H1 and has in contrast to the existing spectrometer a very large acceptance and the possibility of precise calibration. Numerous diffractive processes, such as di-jet production, open charm and vector meson production, have been measured with the existing H1 setup, however with limited statistics and large background contamination from proton-dissociation processes. The new VFPS detector will contribute, in combination with an increased luminosity of the HERA accelerator, to a more precise measurement of these processes. It is therefore expected that, in parallel with theoretical progress, new insights will be gained in the dynamics of diffraction within the framework of the quantum-chromodynamics formalism. The commisioning of the new apparatus and the collection of new data is planned before the end of 2003.

Researcher(s)

• Promoter: De Wolf Eddi
• Fellow: Van Remortel Nick

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

This project aims to contribute to the understanding of diffractive deep-inelastic scattering in two ways: 1. Using the large data sample acquired by the H1 experiment in DESY from 1996 to 2000, a new detailed analysis will be performed of the hadronic final state in diffractive DIS. The much larger number of events will allow a more precise and more differential study of final state characteristics like thrust, energy flow and the multiplicity structure, than previously possible. More specifically, it should now be possible to study the hadronic final state as a function of the photon virtuality and/or the momentum fraction from the pomeron carried by the struck parton. Theory predicts different contributions to the diffractive cross section as a function of these variables. 2. The H1 detector is presently not capable to detect the diffractively scattered proton. Therefore a proposal is being prepared by several member institutes of the H1 collaboration, to install a new proton spectrometer 220~m from the H1 detector, downstream the proton beam. The contribution to this project consists of the study of a new prototype of scintillating fibre detector and the development of reconstruction and calibration software for this future proton spectrometer.

Researcher(s)

• Promoter: De Wolf Eddi
• Fellow: Anthonis Tinne

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

The present project involves the study of the fundamental constituents of matter, and their interactions. The Large Hadron Collider at CERN, operational in 2006, opens exciting perspectives for the discovery of the Brout-Englert-Higgs boson, possible supersymmetric particles and evidence for extra space-time dimensions. The purpose of the present initiative is to increase the collaboration between the belgian research teams in theoretical and experimental particle physics with the aim of contributing in a significant way to one of the most challenging and exciting chapters of modern fundamental research.

Researcher(s)

• Promoter: De Wolf Eddi

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

The subject of this project is the evolution of the structure and interaction of the exchanged photon in electron-proton collisions, as a function of the photon virtuality. To that and the multiparticle final state in photoproduction and deep-inelastic interactions is studied. The particle and transverse energy density, the local and long- range particle correlations and the transverse momentum distribution will provide insight in the dynamica of photon-proton collisions.

Researcher(s)

• Promoter: De Wolf Eddi
• Fellow: Van Mechelen Pierre

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

The research comprises experimental studies of hadron-hadron and lepton-hadron collisions at the highest energies (> 100 GeV/c) performed at particles accelerators at CERN (Geneva), Serpukhov (USSR) and Fermilab (USA). Results are compared with or interpreted in terms of the theories such as Quantumchromodynamics and the Weinberg-Salam theory of the electro-weak interaction.

Researcher(s)

• Promoter: De Wolf Eddi
• Fellow: De Wolf Eddi

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

This project aims to contribute to the understanding of diffractive deep-inelastic scattering in two ways: 1. Using the large data sample acquired by the H1 experiment in DESY from 1996 to 2000, a new detailed analysis will be performed of the hadronic final state in diffractive DIS. The much larger number of events will allow a more precise and more differential study of final state characteristics like thrust, energy flow and the multiplicity structure, than previously possible. More specifically, it should now be possible to study the hadronic final state as a function of the photon virtuality and/or the momentum fraction from the pomeron carried by the struck parton. Theory predicts different contributions to the diffractive cross section as a function of these variables. 2. The H1 detector is presently not capable to detect the diffractively scattered proton. Therefore a proposal is being prepared by several member institutes of the H1 collaboration, to install a new proton spectrometer 220~m from the H1 detector, downstream the proton beam. The contribution to this project consists of the study of a new prototype of scintillating fibre detector and the development of reconstruction and calibration software for this future proton spectrometer.

Researcher(s)

• Promoter: De Wolf Eddi

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project

Abstract

Micro Gap Counters are a new kind of detectors for charged particles. They have the following properties: high spatial resolution, large counting rate, radiation resistent. Different parameters of these detectors will be optimised and a large prototype build, consisting of some 70 elementary cells, 10 by 10 cm each.

Researcher(s)

• Promoter: De Wolf Eddi
• Promoter: Verbeure Frans
• Co-promoter: De Wolf Eddi

Research team(s)

• Particle Physics Group

Project type(s)

• Research Project