Exclusive diffractive photon bremsstrahlung at the LHC

Abstract

We calculate differential distributions for the $pp\to pp\gamma$ reaction at the LHC energy $\sqrt{s}=14$ TeV. We consider diffractive classical bremsstrahlung mechanisms including effects of non point-like nature of protons. In addition, we take into account (vector meson)-pomeron, photon-pion as well as photon-pomeron exchange processes for the first time in the literature. Predictions for the total cross section and several observables related to these processes e.g. differential distributions in pseudorapidities and transverse momenta of photons or protons are shown and discussed. The integrated diffractive bremsstrahlung cross section ($E_{\gamma }>100$ GeV) is only of the order of $\mu$b. We try to identify regions of the phase space where one of the mechanisms dominates. The classical bremsstrahlung dominates at large forward/backward photon pseudorapidities, close to the pseudorapidities of scattered protons. In contrast, the photon-pomeron (pomeron-photon) mechanism dominates at midrapidities but the related cross section is rather small. In comparison the virtual-omega rescattering mechanism contributes at smaller angles of photons (larger photon rapidities). Photons in the forward/backward region can be measured by the Zero Degree Calorimeters (ZDCs) installed in experiments at the LHC while the midrapidity photons are difficult to measure (small cross section, small photon transverse momenta). Protons could be measured by ALFA detector (ATLAS) or TOTEM detector at CMS. The exclusivity could be checked with the help of main central detectors.

16 pages, 12 figures

References in corpus (7)

• Exclusive photoproduction of $J/\psi$ in proton-proton and proton-antiproton scattering
• Measurement of exclusive production of scalar ${\chi }_{c0}$ meson in proton-(anti)proton collisions via ${\chi }_{c0}\to {\pi }^{+}{\pi }^{-}$ decay
• Exclusive $pp\to pp{\pi }^0$ reaction at high energies
• On the sign of the pi-rho-omega coupling constant
• Forward Physics at the LHC, Detecting Elastic pp Scattering by Radiative Photons
• Measurement and analysis of the pp -> pp gamma reaction at 310 MeV
• A model-independent analysis of p + p --> pp(1S0) + gamma

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• Soft-photon radiation in high-energy proton-proton collisions within the tensor-Pomeron approach: Bremsstrahlung
• Central exclusive diffractive production of a single photon in high-energy proton-proton collisions within the tensor-Pomeron approach
• Feasibility Studies of Exclusive Diffractive Bremsstrahlung Measurement at RHIC Energies
• Feasibility Studies of the Diffractive Bremsstrahlung Measurement at the LHC
• Exclusive central diffractive production of scalar, pseudoscalar and vector mesons
• Diffractive Bremsstrahlung at High-${\beta }^{\star }$ LHC Case Study
• Exclusive diffractive bremsstrahlung of one and two photons at forward rapidities: Possibilities for experimental studies in $pp$ collisions at the LHC
• Diffractive Physics at the LHC