1,442 research outputs found
The ATLAS Forward Physics Project
We describe the main components of the ATLAS Forward Physics project, namely
the movable beam pipe, the tracking and timing detectors which allow to detect
intact protons in the final state at the LHC. The position detector is composed
on 6 layers of 3D silicon detectors readout by FE-I4 chips developped for
ATLAS. The fast timing detector is built from a quartz-based Cerenkov detector
coupled to a microchannel plate photomultiplier tube, followed by the
electronic elements that amplify, measure, and record the time of the event
along with a stabilized reference clock signal, ensuring a time resolution of
10-15 picoseconds.Comment: Talk given at the 2012 Nuclear Science Symposium, IEEE, October 29 -
November 3, Anaheim, US
pair production in proton-proton collisions: small missing terms
production is one of the golden channels for testing the Standard
Model as well for searches beyond the Standard Model. We discuss many new
subleading processes for inclusive production of pairs generally not
included in the litterature so far. We focus mainly on photon-photon induced
processes. We include elastic-elastic, elastic-inelastic, inelastic-elastic and
inelastic-inelastic contributions. We also calculate the contributions with
resolved photons including the partonic substructure of the virtual photon.
Predictions for the total cross section and differential distributions in -
boson rapidity and transverse momentum as well as invariant mass are
presented. The components only constitute about 1-2 \% of the
inclusive cross section but increases up to about 10 \% at large
transverse momenta, and are even comparable to the dominant component at large , i.e. are much larger than the
one.Comment: 26 pages, 17 figure and 1 table. arXiv admin note: substantial text
overlap with arXiv:1309.720
Scattering Light by Light at 750 GeV at the LHC
We consider the possibility that the diphoton excess at 750 GeV is caused by
a new scalar resonance produced in photon fusion. This scenario is parametrised
by only one relevant effective couplings and is thus minimal. We show that this
setup can reproduce both the production rate and width of the resonance, and is
not in conflict with the 8 TeV limits on the diphoton cross section. The
scenario also predicts event rates for , , final states. We
suggest to perform precision measurements by studying light-by-light scattering
with intact protons detected in forward detectors. We construct a simple model
that shows that the required couplings can be achieved with new vectorlike,
uncolored fermions (with a strong Yukawa coupling to the resonance) which may
also account for the required width.Comment: 6 pages, minor changes, references added. Matches PRD versio
Exclusive Diffraction at the LHC On behalf of the ATLAS, LHCb, CMS and TOTEM experiments
In this report, we describe the most recent results on exclusive diffraction from the ATLAS, CMS, LHCb, TOTEM experiments at the LHC concerning exclusive pions, J/Ψ, Ψ(2S ), dilepton, diphoton, WW productions and prospects concerning the search for anomalous couplings and axion-like particle production
- …