Adi Bornheim :

A high precision time-of-flight detector for CMS

(Adi, Artur, Javier, Cristian)

A time-of-flight (TOF) detector with a timing resolution of order a few pico
seconds is discussed for the CMS Phase II upgrade for the high luminosity
LHC (HL-LHC). A major challenge at HL-LHC will be the number of simultaneous
interactions per bunch crossing (pile-up, PU). An average of 140 PU interactions
is expected with the accelerator desing currently envisioned for HL-LHC.
Based on toy MC studies and fully simulated events algorithms
have to be developed which allow to associate a vertex location to a physics
object such as a Photon or a Jet. Filtering techniques need to be developed which
allow to suppress energy deposits from pile-up interactions in the object reconstruction.
The goal of the project is to work on the development of these algorithms,
test them on simulated events as well as on real CMS data.

Geant simulation for a high precision time-of-flight detector for CMS

(Cristian, Adi, Artur, Emanuele)

A time-of-flight (TOF) detector with a timing resolution of order a few pico
seconds is discussed for the CMS Phase II upgrade for the high luminosity
LHC (HL-LHC). A major challenge is to develop radiation hard detector technology
which allows the time of flight of all relevant final state particles produced in
LHC proton-proton collisions. A fundamental question is how the physical size
of a calorimetric device limits the achievable timing measurement precision.
The goal of this project is to carry out Geant as well as ray tracing simulation
based on the existing CMS ECAL crystals as well as proposed upgrade options
such as a crystal sampling calorimeter.

ECAL calibration and performance in the presence of radiation induce noise

(Adi, Emanuele)

The noise in the CMS electromagnetic calorimeter (ECAL) increases due to effects of
the radiation environment in LHC. This degrades the resolution performance and
has an impact of the isolation criterion which is used to distinguish electrons
and photons from jets. The increased noise also has an adverse effect on the ability
to select isolated low energy photons, which are used to calibrate the ECAL.
The goal of this project is to measure precisely the impact of the noise on the
ECAL performance and calibration procedure and develop a strategy to mitigate the
effect of the noise.

Emanuele Di Marco :

H->WW->2l2nu with full decay kinematics

CMS data collected at pp collisions at 7 and 8 TeV in LHC Run1
gave an observation for a Higgs-like boson with mass 126 GeV.
For this mass, due to the large BR and very clean final state, one the most
sensitive channel at CMS is H->WW->2l2nu. The problem with this decay
mode is the absence of a clear mass peak due to two undetected
neutrinos. The student should develop an alternative strategy
for the usage of available decay kinematics, in order to
separate the signal from non-resonant WW production and give
access to the mass also in this channel.
If this is achieved, the other informations of the opening
angle of the leptons can be used to determine the spin/parity
of the new particle.

H -> ZZ-> 4 leptons property measurement

CMS data collected at pp collisions at 7 and 8 TeV in LHC Run1
gave an observation for a Higgs-like boson with mass 126 GeV.
The golden mode in terms of sensitivity to the Higgs mass is H -> ZZ
-> 4 leptons final state. The student will study the applications of the full
kinematics available in this channel to characterize the properties of
a possible signal for a resonance in the still allowed mass range to
distinguish a Standard Model Higgs boson from Higgs "look-alikes".
He will also contribute to the experimental analysis using at
best the information on lepton momentum determination to improve
the determination of the mass of the new particle.

Yi Chen

HCAL noise

Javier Duarte

Razoy SUSY

Einstein

Bohr

Information from Summer 2013

Summer2013

Summer Students 2013

Table of contents:

Proposals

Procedure

• Please go ahead and submit your proposal for CERN summer students urgently tomorrow Feb 15.
• Link for potential supervisors to submit a project proposal(s): http://hrapps.cern.ch/auth/f?p=112:1
• Login: AIS login name and password
• Once you have completed your proposal please don't forget to hit the "create" button in order to submit your proposal as otherwise it will not be registered.

Adi Bornheim

Emanuele Di Marco

Artur Apresyan

Alex Mott

Students

Jeff Picard

2

General Information

Information from Summer 2012