Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userTagging Two-Photon Production at the LHC
107
0
0.0
(
0
)
Authors
K. Piotrzkowski
Ask ChatGPT about the research
No Arabic abstract
Tagging two-photon production offers a significant extension of the LHC physics programme. Effective luminosity of high-energy gamma-gamma collisions reaches 1% of the proton-proton luminosity and the standard detector techniques used for measuring very forward proton scattering should allow for a reliable extraction of interesting two-photon interactions. Particularly exciting is a possibility of detecting two-photon exclusive Higgs boson production at the LHC.
rate research
Read More
Photon interactions at the LHC result in striking final states with much lower hadronic activity in the central detectors than for pp interactions. In addition, the elastic exchange of a photon leads to a proton scattered at almost zero-degree angle. Tagging photon interactions relies on either the use of large rapidity gaps or on the detection of the scattered proton using very forward detectors. The studies related to such detectors are presented, including their characterization, their acceptance and reconstruction performance. Limitations due to the LHC beamline misalignment and possible solutions are also given.
A process of Central Exclusive $pi^+pi^-$ production in proton-proton collisions and its theoretical description is presented. A possibility of its measurement, during the special low luminosity LHC runs, with the help of the ATLAS central detector for measuring pions and the ALFA stations for tagging the scattered protons is studied. A visible cross section is estimated to be 21 $mu$b for $sqrt{s}=7$ TeV, which gives over 2000 events for 100 $mu$b$^{-1}$ of integrated luminosity. Differential distributions in pion pseudorapidities, pion and proton transverse momenta as well as $pi^+pi^-$ invariant mass are shown and discussed.
Two-photon events at the LHC are characterized by the protons scattered at very small angles and the particles centrally produced via the photon-photon fusion. To select these events from the huge samples of generic pp interactions a detection of the scattered protons, or tagging two-photon interactions is necessary. It requires installation of the high-resolution position-sensitive detectors close to the proton beam and far from the interaction point. Efficient measurement of the forward-scattered protons will open a new field of studying high-energy photon-photon interactions at remarkable luminosity, reaching 1% of that in pp collisions. In this paper a few aspects of tagging two-photon interactions as well as several most exciting topics in the high-energy two-photon physics at the LHC are presented.
The two-photon exclusive production of charged supersymmetric pairs at the LHC has a clean and unique signature - two very forward scattered protons and two opposite charged leptons produced centraly. For low-mass SUSY scenarios, significant cross-sections are expected and background processes are well controlled. Measurement of the forward proton energies would allow for mass reconstruction of right-handed sleptons and the LSP with a few GeV resolution. Methods to reduce backgrounds at high luminosity resulting from accidental coincidences between events in the central and forward detectors are discussed.
The detection of pairs of sleptons, charginos and charged higgs bosons produced via photon-photon fusion at the LHC is studied, assuming a couple of benchmark points of the MSSM model. Due to low cross sections, it requires large integrated luminosity, but thanks to the striking signature of these exclusive processes the backgrounds are low, and are well known. Very forward proton detectors can be used to measure the photon energies, allowing for direct determination of masses of the lightest SUSY particle, of selectrons and smuons with a few GeV resolution. Finally, the detection and mass measurement of quasi-stable particles predicted by the so-called sweet spot supersymmetry is discussed.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
