Master Thesis Research Projects
The following Master thesis research projects are offered at Nikhef. If you are interested in one of these projects, please contact the coordinator listed with the project.
[MORE PROJECTS TO COME!]
Theory – Probing electroweak symmetry breaking with Higgs pair production at the LHC and beyond
The measurement of Higgs pair production will be a cornerstone of the LHC program in the coming years. Double Higgs production provides a crucial window upon the mechanism of electroweak symmetry breaking, and has a unique sensitivity to a number of currently unknown Higgs couplings, like the Higgs self-coupling λ and the coupling between a pair of Higgs bosons and two vector bosons. In this project, the student will explore the feasibility of the measurement of Higgs pair production in the 4b final state both at the LHC and at future 100 TeV collider. A number of production modes will be considered, including gluon-fusion, vector-boson-fusion, as well as Higgs pair production in association with a top-quark pair. A key ingredient of the project will be the exploitation of multivariate techniques such as Artificial Neural Networks and other multivariate discriminants to enhance the ratio of di-Higgs signal over backgrounds.
The project involves to estimate the precision that can be achieved in the extraction of the Higgs self-coupling for a number of assumptions about the performance of the LHC detectors, and in particular to quantify the information that can be extracted from the Run II dataset with L = 300 1/fb . A similar approach will be applied to the determination of other unknown properties of the Higgs sector, such as the coupling between two Higgs bosons and two weak vector bosons, as well as the Wilson coefficients of higher-dimensional operators in the Standard Model Effective Field Theory (SM-EFT). Additional information on this project can be found here: .
Contact: Juan Rojo
Theory – Constraining the proton structure with Run II LHC data
The non-perturbative dynamics that determine the energy distribution of quarks and gluons inside protons, the so-called parton distribution functions (PDFs), cannot be computed from first principles from Quantum Chromodynamics (QCD), and need to be determined from experimental data. PDFs are an essential ingredient for the scientific program at the Large Hadron Collider (LHC), from Higgs characterisation to searches for New Physics beyond the Standard Model. One recent breakthrough in PDF analysis has been the exploitation of the constraints from LHC data. From direct photons to top quark pair production cross-sections and charmed meson differential distributions, LHC measurements are now a central ingredient of PDF fits, providing important information on poorly-known PDFs such as the large and small-x gluon or the large-x antiquarks. With the upcoming availability of data from the Run II of the LHC, at a center-of-mass energy of 13 TeV, these constraints are expected to become even more stringent.
In this project, the implications of PDF-sensitive measurements at the LHC 13 TeV will be quantified. Processes that will be considered include jet and dijet production at the multi-TeV scale, single-top quark production, and weak boson production in association with heavy quarks, among several others. These studies will be performed using the NNPDF fitting framework, based on artificial neural networks and genetic algorithms. The phenomenological implications of the improved PDF modelling for Higgs and new physics searches at the LHC will also be explored. Additional information on this project can be found here: .
Contact: Juan Rojo
The XENON Dark Matter Experiment: Data Analysis
The XENON collaboration is currently commissioning the XENON1T detector, soon to be the world’s most sensitive direct detection dark matter experiment, with the Nikhef group playing an important role in this work. The detector operates at the Gran Sasso underground laboratory and consists of a so-called dual-phase xenon time-projection chamber filled with 3500kg of ultra-pure xenon. Our group has an opening for a motivated MSc student to do data-analysis on this new detector. The work will consist of understanding the signals that come out of the detector and in particular focus on the so-called double scatter events. We are interested in developing methods in order to interpret the response of the detector better and are developing sophisticated statistical tools to do this. This work will include looking at data and developing new algorithms in our Python-based analysis tool.
Contact: Patrick Decowski
XAMS Dark Matter R&D Setup
The Amsterdam Dark Matter group has built an R&D xenon detector at Nikhef. The detector is a dual-phase xenon time-projection chamber and contains about 4kg of ultra-pure liquid xenon. We plan to use this detector for the development of new detection techniques (such as utilizing new photosensors) and to improve the understanding of the response of liquid xenon to various forms of radiation. The results could be directly used in the XENON experiment, the world’s most sensitive direct detection dark matter experiment at the Gran Sasso underground laboratory. We have several interesting projects for this facility. We are looking for someone who is interested in working in a laboratory on high-tech equipment, modifying the detector, taking data and analyzing the data him/herself. You will "own" this experiment.
Contact: Patrick Decowski