Difference between revisions of "Master student Projects"

From LHCb Wiki
Jump to navigation Jump to search
Line 1: Line 1:
=== Projects for Master students in the Nikhef B-physics (LHCb) group 2017 - 2018===
+
=== Projects for Master students in the Nikhef B-physics (LHCb) group 2020 - 2021 ===
  
date: April 2018
+
date: April 2020
  
 
This is an overview with all available Master student projects in the Nikhef B-physics (LHCb) group.
 
This is an overview with all available Master student projects in the Nikhef B-physics (LHCb) group.
Line 225: Line 225:
 
Decays of B-mesons to a pair of muons or a pair of electrons are very strongly suppressed in the Standard Model. As a consequence these decays are sensitive to virtual contributions of particles beyond the Standard Model. The project includes a theoretical study on these sensitivties and/or experimental improvements to the measurement.   
 
Decays of B-mesons to a pair of muons or a pair of electrons are very strongly suppressed in the Standard Model. As a consequence these decays are sensitive to virtual contributions of particles beyond the Standard Model. The project includes a theoretical study on these sensitivties and/or experimental improvements to the measurement.   
  
 +
 +
 +
{| border="1" cellpadding="2" cellspacing="0"
 +
|-
 +
! style="background:#3399ff;" | <font color=#ffffff> 11) Measurement of Central Exclusive Production Rates of Chi_c using converted photons in LHCb. </font>
 +
|}
 +
 +
''' Supervisor:''' Kazu Akiba
 +
 +
''' Research description: '''
 +
Central exclusive production (CEP) of particles at the LHC is characterised by a extremely clean signature.  Differently from the typical inelastic collisions where many particles are created resulting in a so-called Primary Vertex, CEP events have only the final state particles of interest. In this project the particle of interest is a pair of charmed quarks creating a chi_c particle. In theory this process is generated by a long range gluon exchange and can elucidate the nature of the strong force, described by the quantum chromodynamics in the the standard model. The proposed work involves  analysing a pre-existing dataset with reconstructed chi_c and simulating events at the LHCb in order to obtain the relative occurrence rate of each chi_c species (spins 0, 1, 2), a quantity that can be easily compared to theoretical predictions.
 +
 +
{| border="1" cellpadding="2" cellspacing="0"
 +
|-
 +
! style="background:#3399ff;" | <font color=#ffffff> 12) Optimization studies for Vertex detector at the High Lumi LHCb </font>
 +
|}
 +
 +
''' Supervisor:''' Kazu Akiba
 +
 +
''' Research description: '''
 +
The LHCb experiment is dedicated to measure tiny differences between matter and antimatter through the precise study of rare processes involving b or c quarks.  The LHCb detector will undergo a major modification in order to dramatically increase the luminosity and be able to  measure indirect effects of physics beyond the standard model.  In this environment, over 42 simultaneous collisions are expected to happen at a time interval of 200 ps where the two proton bunches overlap. The particles of interest have a relatively long lifetime and therefore the best way to distinguish them from the background collisions is through the precise reconstruction of displaced vertices and pointing directions.  The new detector considers using extremely recent or even future technologies to measure space (with resolutions below 10 um) and time (100 ps or better) to efficiently reconstruct the events of interest for physics.  The project involves changing completely  the LHCb Vertex Locator (VELO) design in simulation and determine what can be the best performance for the upgraded detector, considering different spatial and temporal resolutions.
 +
 +
 +
{| border="1" cellpadding="2" cellspacing="0"
 +
|-
 +
! style="background:#3399ff;" | <font color=#ffffff> 13) Measurement of charge multiplication in heavily irradiated sensors </font>
 +
|}
 +
 +
''' Supervisor:''' Kazu Akiba
 +
 +
''' Research description: '''
 +
During the R&D phase for the LHCb VELO Upgrade detector a few sensor prototypes were irradiated to the extreme fluence expected to be achieved during the detector lifetime. These samples were tested using high energy particles at the SPS facility at CERN with their trajectories reconstructed by the Timepix3 telescope. A preliminary analysis revealed that at the highest irradiation levels the amount of signal observed is higher than expected, and even larger than the signal obtained at lower doses.  At the Device Under Test (DUT) position inside the telescope, the spatial resolution attained by this system is below 2 um. This means that a detailed analysis can be performed in order to study where and how this signal amplification happens within  the 55x55 um^2 pixel cell.  This project involves analysing the telescope and DUT data to investigate the charge multiplication mechanism at the microscopic level.
 +
 +
 +
<!-- ################################################# -->
 +
<!-- ################################################# -->
 +
<!-- ################################################# -->
 +
<!-- ################################################# -->
  
 
<!--  
 
<!--  
Line 231: Line 269:
 
==============
 
==============
  
 +
<!-- ################################################# -->
 
  Commented out Nov 2014 by Niels (Elise is on this project)
 
  Commented out Nov 2014 by Niels (Elise is on this project)
  
Line 239: Line 278:
  
 
''' Supervisors:''' Wouter Hulsbergen (staf) and Veerle Heijne (PhD)
 
''' Supervisors:''' Wouter Hulsbergen (staf) and Veerle Heijne (PhD)
 
 
''' Research description: '''
 
''' Research description: '''
  
Line 251: Line 289:
 
The ROOT programme and C++ and/or Python macros are used. You become part of our research group
 
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.  
 
(~5 persons); we have weekly video meetings with colleagues at CERN.  
 
  
 
''' Relevant information: '''
 
''' Relevant information: '''
 
 
Master thesis Suzanne Klaver (2013):  
 
Master thesis Suzanne Klaver (2013):  
 
[http://www.nikhef.nl/pub/experiments/bfys/lhcb/Theses/master/2013_SuzanneKlaver.pdf A Search for Long-lived Neutralinos in LHCb]
 
[http://www.nikhef.nl/pub/experiments/bfys/lhcb/Theses/master/2013_SuzanneKlaver.pdf A Search for Long-lived Neutralinos in LHCb]
  
 
End comment Niels Nov 2014 -->
 
End comment Niels Nov 2014 -->
 +
<!-- ################################################# -->
  
 +
<!-- ################################################# -->
 
<!-- Commented out July 2014 Niels
 
<!-- Commented out July 2014 Niels
  
Line 265: Line 303:
 
2) World's best measurement of the Bc+ mass with Bc+ -> Bs pi+  
 
2) World's best measurement of the Bc+ mass with Bc+ -> Bs pi+  
 
</font>|}
 
</font>|}
+
''' Supervisors:''' Niels Tuning (staf), Jacco de Vries (PhD)
''' Supervisors:''' Niels Tuning (staf), Jacco de Vries (PhD)
 
 
 
''' Research description: '''
 
''' Research description: '''
  
Line 289: Line 325:
 
''' Relevant information: '''
 
''' Relevant information: '''
 
 
Master thesis Jacco de Vries (2013):
+
[1] Master thesis Jacco de Vries (2013):
 
[http://www.nikhef.nl/pub/experiments/bfys/lhcb/Theses/maste/2013_JaccoDeVries.pdf First observation of the decay Bc+ -> B0s pi+]
 
[http://www.nikhef.nl/pub/experiments/bfys/lhcb/Theses/maste/2013_JaccoDeVries.pdf First observation of the decay Bc+ -> B0s pi+]
 
 
LHCb collaboration, arXiv:1308.4544 (2013): [http://arxiv.org/abs/1308.4544 Observation of the decay Bc+ -> Bs pi+]
+
[2] LHCb collaboration, arXiv:1308.4544 (2013): [http://arxiv.org/abs/1308.4544 Observation of the decay Bc+ -> Bs pi+]
  
R. Fleischer, N. Serra and N. Tuning, Phys. Rev. D 83, 014017 (2011)
+
[3] R. Fleischer, N. Serra and N. Tuning, Phys. Rev. D 83, 014017 (2011)
 
[http://arxiv.org/abs/arXiv:1012.2784 Tests of Factorization and SU(3) Relations in B Decays into Heavy-Light Final States]
 
[http://arxiv.org/abs/arXiv:1012.2784 Tests of Factorization and SU(3) Relations in B Decays into Heavy-Light Final States]
  
 
End comment Niels Jul 2014-->
 
End comment Niels Jul 2014-->
 +
<!-- ################################################# -->
  
 
+
<!-- ################################################# -->
 
<!-- Commented out 2014 Marcel
 
<!-- Commented out 2014 Marcel
 
{| border="1" cellpadding="2" cellspacing="0"
 
{| border="1" cellpadding="2" cellspacing="0"
Line 305: Line 342:
 
! style="background:#3399ff;" | <font color=#ffffff> 2) Light Higgs search A0 -> mu+mu- </font>
 
! style="background:#3399ff;" | <font color=#ffffff> 2) Light Higgs search A0 -> mu+mu- </font>
 
|}
 
|}
 
 
 
''' Supervisors:''' Wouter Hulsbergen (staf), Pieter David (PhD)
 
''' Supervisors:''' Wouter Hulsbergen (staf), Pieter David (PhD)
 
 
 
''' Research description: '''
 
''' Research description: '''
 
 
Supersymmetry is potentially the key to understand the Dark Matter in the Universe.
 
Supersymmetry is potentially the key to understand the Dark Matter in the Universe.
 
In supersymmetry, there is not just one Higgs boson as in the Standard Model,
 
In supersymmetry, there is not just one Higgs boson as in the Standard Model,
Line 322: Line 354:
 
This is a new project, within the small group at Nikhef (~3 persons). The analysis resembles the search for the
 
This is a new project, within the small group at Nikhef (~3 persons). The analysis resembles the search for the
 
decay Bs->mu+mu-, which was discovered this Summer and led to a lot of attention.
 
decay Bs->mu+mu-, which was discovered this Summer and led to a lot of attention.
 
  
 
''' Relevant information: '''
 
''' Relevant information: '''
 
 
LHCb collaboration, arXiv:1307.5024
 
LHCb collaboration, arXiv:1307.5024
 
[http://arxiv.org/pdf/1307.5024.pdf Measurement of the B0s->mu+mu- branching fraction and search for B0->mu+mu- decays at the LHCb experiment]
 
[http://arxiv.org/pdf/1307.5024.pdf Measurement of the B0s->mu+mu- branching fraction and search for B0->mu+mu- decays at the LHCb experiment]
  
 
End comment Marcel -->
 
End comment Marcel -->
 +
<!-- ################################################# -->
  
 +
<!-- ################################################# -->
 
<!-- Commented out Marcel 2014
 
<!-- Commented out Marcel 2014
 
{| border="1" cellpadding="2" cellspacing="0"
 
{| border="1" cellpadding="2" cellspacing="0"
Line 338: Line 370:
  
 
''' Supervisors:''' Gerhard Raven (staf), Vasilis Syropoulos (PhD)
 
''' Supervisors:''' Gerhard Raven (staf), Vasilis Syropoulos (PhD)
 
 
 
''' Research description: '''
 
''' Research description: '''
  
Line 354: Line 384:
 
This is a project that is closely related to the larger effort at Nikhef (~5 people) of measuring phi_s with
 
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.
 
Bs->J/psiPhi decays. Weekly video meetings with CERN coordinate the efforts within the LHCb collaboration.
 
  
 
''' Relevant information: '''
 
''' Relevant information: '''
Line 362: Line 391:
  
 
End comment Marcel -->
 
End comment Marcel -->
 +
<!-- ################################################# -->
  
 +
<!-- ################################################# -->
 
<!-- Commented out Nov 2014 by Niels (Georgios is on this project)
 
<!-- Commented out Nov 2014 by Niels (Georgios is on this project)
  
Line 369: Line 400:
 
! style="background:#3399ff;" | <font color=#ffffff> 2) Searching for Lorentz Invariance Violation with Bs -> J/psi phi decays </font>
 
! style="background:#3399ff;" | <font color=#ffffff> 2) Searching for Lorentz Invariance Violation with Bs -> J/psi phi decays </font>
 
|}
 
|}
 
 
 
''' Supervisors:''' Gerhard Raven (staf), Jeroen van Tilburg (Postdoc)
 
''' Supervisors:''' Gerhard Raven (staf), Jeroen van Tilburg (Postdoc)
 
 
 
''' Research description: '''
 
''' Research description: '''
  
Line 382: Line 409:
 
This is a project that is closely related to the larger effort at Nikhef (~5 people) of measuring phi_s with
 
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.
 
Bs->J/psiPhi decays. Weekly video meetings with CERN coordinate the efforts within the LHCb collaboration.
 
  
 
''' Relevant information: '''
 
''' Relevant information: '''
 
 
Belle Collaboration: arXiv:1203.0930v2,
 
Belle Collaboration: arXiv:1203.0930v2,
 
[http://arxiv.org/pdf/1203.0930.pdf  Search for Time-Dependent CPT Violation in Hadronic and Semileptonic B Decays]
 
[http://arxiv.org/pdf/1203.0930.pdf  Search for Time-Dependent CPT Violation in Hadronic and Semileptonic B Decays]
  
 
End comment Niels Nov 2014 -->
 
End comment Niels Nov 2014 -->
 +
<!-- ################################################# -->
  
 +
<!-- ################################################# -->
 
<!-- Comment Marcel 2014
 
<!-- Comment Marcel 2014
 
{| border="1" cellpadding="2" cellspacing="0"
 
{| border="1" cellpadding="2" cellspacing="0"
Line 398: Line 425:
  
 
''' Supervisors:''' Francesco Dettori (postdoc), Antonio Pellegrino (staf), Siim Tolk (PhD)
 
''' Supervisors:''' Francesco Dettori (postdoc), Antonio Pellegrino (staf), Siim Tolk (PhD)
 
 
 
''' Research description: '''
 
''' Research description: '''
 
 
The decay Sigma+ -> p mu mu is very rare in the Standard Model. In 2005 the  
 
The decay Sigma+ -> p mu mu is very rare in the Standard Model. In 2005 the  
 
HyperCP experiment has seen first evidence of this decay, but with a very peculiar  
 
HyperCP experiment has seen first evidence of this decay, but with a very peculiar  
Line 413: Line 437:
 
Python macros are used. This is a small project, where the student can perform  
 
Python macros are used. This is a small project, where the student can perform  
 
his research in an independent way.  
 
his research in an independent way.  
 
 
This research will likely result in an official LHCb publication.
 
This research will likely result in an official LHCb publication.
 
  
 
''' Relevant information: '''
 
''' Relevant information: '''
  
HyperCP Collaboration, Phys. Rev. Lett. 94, 021801 (2005)
+
[1] HyperCP Collaboration, Phys. Rev. Lett. 94, 021801 (2005)
 
[http://arxiv.org/abs/hep-ex/0501014 Evidence for the decay Sigma+ -> p mu mu]
 
[http://arxiv.org/abs/hep-ex/0501014 Evidence for the decay Sigma+ -> p mu mu]
 
+
[2] X.-G. He, J. Tandean, G. Valencia, Phys. Rev. Lett. 98, 081802 (2007)
X.-G. He, J. Tandean, G. Valencia, Phys. Rev. Lett. 98, 081802 (2007)
 
 
[http://arxiv.org/abs/hep-ph/0610362 Has HyperCP Observed a Light Higgs Boson?]
 
[http://arxiv.org/abs/hep-ph/0610362 Has HyperCP Observed a Light Higgs Boson?]
  
 
End comment Marcel -->
 
End comment Marcel -->
 +
<!-- ################################################# -->
  
 
+
<!-- ################################################# -->
 
 
 
<!-- Commented out Marcel April 2016
 
<!-- Commented out Marcel April 2016
  
Line 435: Line 456:
 
! style="background:#3399ff;" | <font color=#ffffff> 1) Bs->mumu and Bd->mumu normalization and B mesons hadronization probabilities </font>
 
! style="background:#3399ff;" | <font color=#ffffff> 1) Bs->mumu and Bd->mumu normalization and B mesons hadronization probabilities </font>
 
|}
 
|}
 
 
''' Supervisors:''' Antonio Pellegrino (staff), Maarten van Veghel (PhD)
 
''' Supervisors:''' Antonio Pellegrino (staff), Maarten van Veghel (PhD)
 
 
''' Research description: '''
 
''' Research description: '''
  
Line 467: Line 486:
  
 
''' Relevant information: '''
 
''' Relevant information: '''
 
 
[1] R.Aaij et al. [LHCb Collaboration], ``Measurement of the fragmentation fraction ratio f_s/f_d and its
 
[1] R.Aaij et al. [LHCb Collaboration], ``Measurement of the fragmentation fraction ratio f_s/f_d and its
 
dependence on B meson kinematics'', JHEP 04 (2013) 001 [arXiv:1301.5286 [hep-ph]].
 
dependence on B meson kinematics'', JHEP 04 (2013) 001 [arXiv:1301.5286 [hep-ph]].
  
 
End comment Marcel April 2016 -->
 
End comment Marcel April 2016 -->
 +
<!-- ################################################# -->
  
 +
 +
<!-- ################################################# -->
 
<!-- Commented out May 2015 by Niels (Siim, Maarten, Mick already on the project)
 
<!-- Commented out May 2015 by Niels (Siim, Maarten, Mick already on the project)
 
 
{| border="1" cellpadding="2" cellspacing="0"
 
{| border="1" cellpadding="2" cellspacing="0"
 
|-
 
|-
 
! style="background:#3399ff;" | <font color=#ffffff> 3) Measurement of pt and eta dependence of B0 and Bs0 production </font>
 
! style="background:#3399ff;" | <font color=#ffffff> 3) Measurement of pt and eta dependence of B0 and Bs0 production </font>
 
|}
 
|}
 
 
''' Supervisors:''' Niels Tuning (staf), ... ?
 
''' Supervisors:''' Niels Tuning (staf), ... ?
 
 
''' Research description: '''
 
''' Research description: '''
 
 
The relative production fractions ("fs/fd") of B0 (with quark content bd) and Bs0 (with quark content bs)
 
The relative production fractions ("fs/fd") of B0 (with quark content bd) and Bs0 (with quark content bs)
 
mesons is crucial for the determination of the branching fraction of any Bs0 decay at the LHC. The most
 
mesons is crucial for the determination of the branching fraction of any Bs0 decay at the LHC. The most
Line 499: Line 516:
  
 
''' Relevant information: '''
 
''' Relevant information: '''
 
 
[1] R.Aaij et al. [LHCb Collaboration], ``Measurement of the fragmentation fraction ratio f_s/f_d and its
 
[1] R.Aaij et al. [LHCb Collaboration], ``Measurement of the fragmentation fraction ratio f_s/f_d and its
 
dependence on B meson kinematics'', JHEP 04 (2013) 001 [arXiv:1301.5286 [hep-ph]].
 
dependence on B meson kinematics'', JHEP 04 (2013) 001 [arXiv:1301.5286 [hep-ph]].
 
 
[2] R.Aaij et al. [LHCb Collaboration], ''Measurement of the B0s??+?? branching fraction and search for
 
[2] R.Aaij et al. [LHCb Collaboration], ''Measurement of the B0s??+?? branching fraction and search for
 
B0??+?? decays at the LHCb experiment'', Phys.Rev.Lett. 111 (2013) 101805  [arXiv:1307.5024 [hep-ph]]
 
B0??+?? decays at the LHCb experiment'', Phys.Rev.Lett. 111 (2013) 101805  [arXiv:1307.5024 [hep-ph]]
  
 
End comment Niels May 2015-->
 
End comment Niels May 2015-->
 +
<!-- ################################################# -->
  
  
 +
<!-- ################################################# -->
 
<!-- Commented out Marcel April 2016
 
<!-- Commented out Marcel April 2016
  
Line 526: Line 543:
  
 
End comment Marcel April 2016 -->
 
End comment Marcel April 2016 -->
 +
<!-- ################################################# -->
  
 +
<!-- ################################################# -->
 
<!-- Commented out Marcel April 2016
 
<!-- Commented out Marcel April 2016
 
 
{| border="1" cellpadding="2" cellspacing="0"
 
{| border="1" cellpadding="2" cellspacing="0"
 
|-
 
|-
Line 535: Line 553:
  
 
''' Supervisors:''' Jeroen can Tilburg (Vidi Laureate)
 
''' Supervisors:''' Jeroen can Tilburg (Vidi Laureate)
 
 
''' Research description: '''
 
''' Research description: '''
 
 
When two particles are created in an anti-symmetric wave function, the two particles are entangled, even though they may be separated by large distances.  
 
When two particles are created in an anti-symmetric wave function, the two particles are entangled, even though they may be separated by large distances.  
 
If one of the particles is forced into one state (projection), this determines the other state instantaneously. Several theoretical models,  
 
If one of the particles is forced into one state (projection), this determines the other state instantaneously. Several theoretical models,  
Line 545: Line 561:
  
 
End Comment Marcel April 2016-->
 
End Comment Marcel April 2016-->
 
+
<!-- ################################################# -->
{| border="1" cellpadding="2" cellspacing="0"
 
|-
 
! style="background:#3399ff;" | <font color=#ffffff> 11) Measurement of Central Exclusive Production Rates of Chi_c using converted photons in LHCb. </font>
 
|}
 
 
 
''' Supervisor:''' Kazu Akiba
 
 
 
''' Research description: '''
 
Central exclusive production (CEP) of particles at the LHC is characterised by a extremely clean signature.  Differently from the typical inelastic collisions where many particles are created resulting in a so-called Primary Vertex, CEP events have only the final state particles of interest. In this project the particle of interest is a pair of charmed quarks creating a chi_c particle. In theory this process is generated by a long range gluon exchange and can elucidate the nature of the strong force, described by the quantum chromodynamics in the the standard model. The proposed work involves  analysing a pre-existing dataset with reconstructed chi_c and simulating events at the LHCb in order to obtain the relative occurrence rate of each chi_c species (spins 0, 1, 2), a quantity that can be easily compared to theoretical predictions.
 
 
 
{| border="1" cellpadding="2" cellspacing="0"
 
|-
 
! style="background:#3399ff;" | <font color=#ffffff> 12) Optimization studies for Vertex detector at the High Lumi LHCb </font>
 
|}
 
 
 
''' Supervisor:''' Kazu Akiba
 
 
 
''' Research description: '''
 
The LHCb experiment is dedicated to measure tiny differences between matter and antimatter through the precise study of rare processes involving b or c quarks.  The LHCb detector will undergo a major modification in order to dramatically increase the luminosity and be able to  measure indirect effects of physics beyond the standard model.  In this environment, over 42 simultaneous collisions are expected to happen at a time interval of 200 ps where the two proton bunches overlap. The particles of interest have a relatively long lifetime and therefore the best way to distinguish them from the background collisions is through the precise reconstruction of displaced vertices and pointing directions.  The new detector considers using extremely recent or even future technologies to measure space (with resolutions below 10 um) and time (100 ps or better) to efficiently reconstruct the events of interest for physics.  The project involves changing completely  the LHCb Vertex Locator (VELO) design in simulation and determine what can be the best performance for the upgraded detector, considering different spatial and temporal resolutions.
 
 
 
 
 
{| border="1" cellpadding="2" cellspacing="0"
 
|-
 
! style="background:#3399ff;" | <font color=#ffffff> 13) Measurement of charge multiplication in heavily irradiated sensors </font>
 
|}
 
 
 
''' Supervisor:''' Kazu Akiba
 
 
 
''' Research description: '''
 
During the R&D phase for the LHCb VELO Upgrade detector a few sensor prototypes were irradiated to the extreme fluence expected to be achieved during the detector lifetime. These samples were tested using high energy particles at the SPS facility at CERN with their trajectories reconstructed by the Timepix3 telescope. A preliminary analysis revealed that at the highest irradiation levels the amount of signal observed is higher than expected, and even larger than the signal obtained at lower doses.  At the Device Under Test (DUT) position inside the telescope, the spatial resolution attained by this system is below 2 um. This means that a detailed analysis can be performed in order to study where and how this signal amplification happens within  the 55x55 um^2 pixel cell.  This project involves analysing the telescope and DUT data to investigate the charge multiplication mechanism at the microscopic level.
 

Revision as of 13:55, 14 April 2020