Forward Physics at the LHC: from the Structure of the Pomeron to the Search for $\gamma $-induced Resonances

Abstract

We describe some of the future measurements to be performed by the CMS, TOTEM and ATLAS collaborations on hard diffraction in order to understand better the structure of the Pomeron. We also describe the prospects concerning the search for quartic γγγγ anomalous couplings and discuss a possible interpretation for the existence of a new particle decaying into two photons at a mass of about 750 GeV.In this short review, we will describe some potential measurements to be performed at the LHC mainly in the ATLAS, CMS-TOTEM, CT-PPS experiments in order to get a better understanding of diffraction and photonexchange processes. Of special interest will be the discussion of beyond standard model reaches especially in the di-photon channel that might be the firt sign of new physics. These studies follow a long term collaboration with Prof. Andrzej Bialas and Prof. Robert Peschanski that started after my PhD in Saclay about the dipole model and diffraction [1] and I would like to express all my gratitude to Andrezj for this long term and successful collaboration, and to wish him a very nice birthday for this occasion. Experimental definition of diffraction and measurement of the gluon density in the Pomeron at HERAIn this section, we discuss the different experimental ways to define diffraction. As an example, we describe the methods used by the H1 and ZEUS experiments at HERA, DESY, Hamburg in Germany since it is the starting point for any diffraction studies at the LHC (most of the quark and gluon densities in the Pomeron were obtained using HERA data). In addition, many results concerning diffraction have been obtained at the Tevatron and the LHC will allow to extend these measurements in a completely new kinematical domain.(1)

LHC searches for Dark Matter in compressed mass scenarios: challenges in the forward proton mode

“…That is, the production cross sections are directly predicted in terms of the electric charges of the relevant states. Now, the development of the forward proton detectors (FPD) at the LHC allows us to perform a wide program of such searches [39][40][41][42][43][44][45][46][47][48]. In particular, dedicated AFP [49,50] and CT-PPS [51] FPDs have recently been installed in association with both ATLAS and CMS, respectively.…”