Proton-proton forward scattering at the LHC

Abstract

Recently the TOTEM experiment at the LHC has released measurements at √ s = 13 TeV of the proton-proton total cross section, σtot, and the ratio of the real to imaginary parts of the forward elastic amplitude, ρ. Since then an intense debate on the C-parity asymptotic nature of the scattering amplitude was initiated. We examine the proton-proton and the antiproton-proton forward data above 10 GeV in the context of an eikonal QCD-based model, where nonperturbative effects are readily included via a QCD effective charge. We show that, despite an overall satisfactory description of the forward data is obtained by a model in which the scattering amplitude is dominated by only crossing-even elastic terms, there is evidence that the introduction of a crossing-odd term may improve the agreement with the measurements of ρ at √ s = 13 TeV. In the Regge language the dominant even(odd)-under-crossing object is the so called Pomeron (Odderon).

Determination of the entanglement entropy in elastic scattering using model-independent method for hadron femtoscopy

“…For instance, the measured value at the LHC by the TOTEM Collaboration at 13 TeV is R el = 0.281 ± 0.009 [21] and the eikonal model gives R eik el = 0.23. On the other hand, one-channel eikonal models based on QCD with nonperturbative effects included through a QCD effective charge are able to successfully describe the LHC data [31,32]. At high energies, Eq.…”

Soft diffraction within the QCD color dipole picture

“…Here, we will use the value m G = 400 MeV that is consistent with the usual values in Refs. [43][44][45]. Moreover, the gluon PDF probed in the low scale µ 2 = m 2 G = 0.16 GeV 2 will be given by a prediction from the parton saturation physics,…”