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

W+W−W^+ W^- pair production in proton-proton collisions: small missing terms

$W^+ W^-$ 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 $W^+ W^-$ 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 $W$- boson rapidity and transverse momentum as well as $WW$ invariant mass are presented. The $\gamma \gamma$ components only constitute about 1-2 \% of the inclusive $W^+ W^-$ cross section but increases up to about 10 \% at large $W^{\pm}$ transverse momenta, and are even comparable to the dominant $q \bar q$ component at large $M_{WW}$, i.e. are much larger than the $g g \to W^+ W^-$ 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 $WW$, $ZZ$, $Z\gamma$ 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

The odderon discovery by the D0 and TOTEM collaborations

We describe the discovery of the colorless $C$-odd gluonic compound, the odderon, by the D0 and TOTEM Collaborations by comparing elastic differential cross sections measured in $pp$ and $p \bar{p}$ interactions at high energies.Comment: Proceeding of the 35th annual meeting of the Particle and Field Division of the Mexican Physical Society, RADPyC 2021, 11-13 May 2021, Mexic