Research Pierre Van Mechelen

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

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

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

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

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

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

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 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

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

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

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

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

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 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 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

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 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 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 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

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 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 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)

Project type(s)

• Research Project