1. Measurement of exclusive processes and
search for New Physics at the LHC
Presentation of the PhD project of
Mohammed El Amine BENAICHOUCHE
With professor
Krzysztof PIOTRZKOWSKI
Introduction : Master’s project and CERN summer school.
Photon interactions and exclusive production at the LHC.
Anomalous Quartic Gauge couplings
Novel forward detectors
Work plan
Outline

2. Introduction : Master’s project
The Quark-Parton Model
• Quark Model
• The Parton Model.
• Gluons and QCD corrections
• The improved Parton Model
– Parton evolution equations (DGLAP)
• Experimental determination of the PDFs.
– Studied these processes
– Discussed results of HERA experiments (H1 and ZEUS)
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3. The H1 and ZEUS measurements of the cross section of
the NC and CC ep cross sections as a function of Q2
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The Valance and Sea quark, and gluon distributions as obtained
from H1 and ZEUS NLO QCD fits to NC , CC and Jet Data at Q2 =
10 GeV2 as a function of x

4. 2010 CERN Summer student project:
• Importance of the Vector Boson Fusion
processes (VBF)  production of the Higgs boson
• Study of the Triple Gauge Bosons Vertices
(TGCs) in VBF at the LHC
• The studied process was production of Z boson via fusion of two W bosons
with
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5. • Studying the automatic computations from Lagrangian to Event level.
• Event generator : CalcHEP
• Experimental cuts (on the kinematic variables).
• Studies of the decay of Z boson using CalcHEP-PYTHIA interface and CMSSW.
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6. Two photon physics at the LHC.
• The LHC as a parasitic photon collider.
• Two Photon interaction : Photon-photon fusion
• Photons are exchanged by both protons and fuse to
produce centrally a system X
• In exclusive production both protons survive
importance of new forward detectors.
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7. Physics potential of two photons interactions:
• Measurements of two-photon production of W boson pairs
 unique test of Quartic Gauge Couplings (QGCs)
• Possibility of direct pair production of new massive charged
particles, as sleptons or charginos in SUSY
• Exclusive production of the Higgs boson
• QED exclusive production muon pairs for absolute calibration
luminosity at the LHC.
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8. With limited statistics of ~100 events
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First measurements of exclusive two-photon production
at the LHC (2010 data)

9. 2011 summer project at CP3
• Continue measurements of exclusive two-photon interaction at the LHC
using 2011 (in collaboration with J. Hollar and N. Schul)
• Simulations : LPAIR event generator.
• Developing new methods for events selection :
- Kinematics selection.
- Efficiency corrections.
- etc.
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10. Anomalous Quartic Gauge Couplings.
• Fundamental importance of studies of Quartic Gauge Vertices
W + W  W + W and Higgs mechanism.
- Quartic Gauge Couplings are not well studied
 Any anomaly is a direct sign of New Physics!
• Two photon interactions offer unique opportunity
at the LHC  studies of ggWW (and ggZZ) vertex
• Theoretical models need to be implemented to simulate anomalous QGCs
(using effective lagrangians)
• New methods and techniques will be developed to complete the study
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11. Novel forward detectors – GasToF detector
• High Precision Spectrometer (HPS) project in CMS involves installation far from
collision point of very-forward detectors close to the beam line of the LHC
• GasToF : Gas Cherenkov counter proposed by a CP3 group for picosecond
resolution Time-of-Flight measurements of forward scattered protons
• GasToF : detection of Cerenkov light (after reflection by a mirror) by ultra rapid
micro-channel plate photomultipliers (MCP-PMTs)
• Detailed simulations of the detector performance will be confronted with
future studies using cosmic rays/at test beams
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Event display using Frog program for a given
geometry of GasToF
GasToF concept

12. Work Plan
• 2011-2012 :
- Measurement of exclusive lepton pair production using 2011 data in CMS.
- Start of a complete study of the ggWW couplings.
- Complete GasToF simulation and test performance of the detector.
• 2013-2014 :
- Publish the first results of the QGCs measurements in CMS.
- Preparations for measurement of the exclusive processes at the energies
of 14 TeV using HPS and its novel detectors .
• 2015 :
- First measurement of photon interaction using new 14 TeV data.
- Finalize analyses and publish PhD thesis.
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