Master student Projects

Projects for Master students in the Nikhef B-physics (LHCb) group

date: May 2014

This is an overview with all available Master student projects in the Nikhef B-physics (LHCb) group.

If you have your own research proposal, need more detailed information on the (availability) of individual proposals or would like to discuss about other available projects in the group you are always welcome to contact either the contact person for the project and/or the Nikhef B-physics group leader:

Marcel Merk [e-mail: i93_at_nikhef.nl, Tel 020-5925107, Nikhef room N2xx]

For an overview of the theses written in the Nikhef B-physics group you can look at the Nikhef LHCb theses page

Master projects in the Nikhef B-physics group

1) Study of long-living particles

Supervisors: Wouter Hulsbergen (staf) and Veerle Heijne (PhD)

Research description:

Supersymmetry is potentially the key to understand the Dark Matter in the Universe. Within the SUSY framework, long-living supersymmetric particles can exist, which can be detected by the LHCb detector. The search for these particles will be performed on the recent data set recorded in 2012, and some work is also needed on the trigger selection, to prepare for data taking in 2015, when the LHC will be running at a higher center-of-mass energy.

For this project computer skills are needed. The ROOT programme and C++ and/or Python macros are used. You become part of our research group (~5 persons); we have weekly video meetings with colleagues at CERN.

Relevant information:

Master thesis Suzanne Klaver (2013): A Search for Long-lived Neutralinos in LHCb

2) World's best measurement of the Bc+ mass with Bc+ -> Bs pi+

Supervisors: Niels Tuning (staf), Jacco de Vries (PhD)

Research description:

At Nikhef we recently discovered the first weak B-decay with another B-to-B decay: Bc+ -> Bs pi+. The mass difference between the Bc+ and Bs meson is very small (only about 0.9 GeV), and as a result the mass difference can be accurately determined. This will lead to the world's best measurement of the Bc+ mass.

A theoretical component (in collaboration with Robert Fleischer) can be added to this project, by examining the various possible Bc+ decay modes, and make quantitative predictions for the relative branching fractions. Investigating the various decay modes, can lead to a method for determining the absolute production rate of Bc+ mesons at the LHC, which is at present still unknown.

For this project computer skills are needed. The ROOT programme and C++ and/or Python macros are used. This is a small project, where the student can perform his research in an independent way. The group at Nikhef (~2 persons) collaborates with a small group at CERN that studies the same decay, but with a different Bs final state. This research will likely result in an official LHCb publication.

Relevant information:

Master thesis Jacco de Vries (2013): First observation of the decay Bc+ -> B0s pi+

LHCb collaboration, arXiv:1308.4544 (2013): Observation of the decay Bc+ -> Bs pi+

R. Fleischer, N. Serra and N. Tuning, Phys. Rev. D 83, 014017 (2011) Tests of Factorization and SU(3) Relations in B Decays into Heavy-Light Final States

3) Searching for Lorentz Invariance Violation with Bs -> J/psi phi decays

Supervisors: Gerhard Raven (staf), Jeroen van Tilburg (Postdoc)

Research description:

The measurement of CP violation occurring in decays of the type Bs-->J/psi phi is a flagship analysis in the LHCb experiment. However, no-one in LHCb has tested whether CPT symmetry is violated. CPT symmetry is tightly connected to the principle of Lorentz invariance. Lorentz invariantz violation would become visible if the decay rate would show any dependency to a fixed direction in space. In this project the CP violation analysis is extended to test for Lorentz Invariance violation.

For this project computer skills are needed. The ROOT programme and C++ and/or Python macros are used. This is a project that is closely related to the larger effort at Nikhef (~5 people) of measuring phi_s with Bs->J/psiPhi decays. Weekly video meetings with CERN coordinate the efforts within the LHCb collaboration.

Relevant information:

Belle Collaboration: arXiv:1203.0930v2, Search for Time-Dependent CPT Violation in Hadronic and Semileptonic B Decays