The Strong Interaction at the Collider and Cosmic-Rays Frontiers

Abstract

First data on inclusive particle production measured in proton-proton collisions at the Large Hadron Collider (LHC) are compared to predictions of various hadron-interaction Monte Carlos (QGSJET, EPOS and SIBYLL) used commonly in high-energy cosmic-ray physics. While reasonable overall agreement is found for some of the models, none of them reproduces consistently the √ s evolution of all the measured observables. We discuss the implications of the new LHC data for the modeling of the non-perturbative and semihard parton dynamics in hadron-hadron and cosmic-rays interactions at the highest energies studied today.

Introduction to Forward Physics and Cosmic Rays at the Symposium on Multiparticle Dynamics ISMD 2010

“…As discussed in Ref. [53], the experimentally observed smooth energy behavior of the multiplicity of charged hadrons in the √ s = 0.9 ÷ 7 TeV range supports conventional astrophysical interpretations of cosmic ray data in the discussed energy range, in particular concerning the "knee" around 3 · 10 6 GeV [56], in contrast with claims on exotic physics (e.g. [57]) being responsible for the observed features of the CR spectrum.…”

“…In Ref. [53] the predictions of hadronic Monte Carlo generators used in the CR field have been compared to the results of the CMS [54] and ALICE [55] collaborations on soft multiparticle production. While none of the models considered provided a sufficiently good description of the complete set of the available LHC data, the experimental results on the pseudorapidity density of produced charged hadrons appeared to be well bracketed by the CR model predictions.…”

Introduction to the physics of the total cross section at LHC

“…One word of caution is, however, put forward by these authors, namely that the non-linear logarithmic rise of the elastic slope is basically determined by the recent TOTEM measurement of B(7 TeV) ∼ 20 GeV 2 . Up to and including the TeVatron measurement, a linear logarithmic energy rise for B el is in fact actually still compatible, as one can see from Fig. 70. …”

“…A short review by D'Enterria et al [70] deals with various hadronic quantities entering cosmic rays analyses, such as multiplicity distributions and energy flow. In addition, extracting an inelastic cross section from total and elastic scattering requires, in most models, a theoretical description of diffraction, single and double, low and high mass.…”

Strange fireball as an explanation of the muon excess in Auger data

“…with s in appropriate units of GeV 2 [39]. On the other hand, for a cosmic-ray nitrogen nucleus (for simplicity, we choose the beam nucleus to be that of the dominant element in air 4 ) of E ≈ 10 10 GeV colliding with an air nucleus, we have √ s ≈ 10 4.6 A GeV, yielding p T ∼ 0.69 GeV and (dN ch /dη) η=0 ∼ 7 [40]. Throughout, we take A = 14 as fiducial in our calculations and assume that half of these number of nucleons interact per collision, producing the fireball.…”