High energy physics in the atmosphere: phenomenology of cosmic ray air showers

Abstract

The properties of cosmic rays with energies above 10 6 GeV have to be deduced from the spacetime structure and particle content of the air showers which they initiate. In this review we summarize the phenomenology of these giant air showers. We describe the hadronic interaction models used to extrapolate results from collider data to ultra high energies, and discuss the prospects for insights into forward physics at the LHC. We also describe the main electromagnetic processes that govern the longitudinal shower evolution, as well as the lateral spread of particles. Armed with these two principal shower ingredients and motivation from the underlying physics, we provide an overview of some of the different methods proposed to distinguish primary species. The properties of neutrino interactions and the potential of forthcoming experiments to isolate deeply penetrating showers from baryonic cascades are also discussed. We finally venture into a terra incognita endowed with TeV-scale gravity and explore anomalous neutrino-induced showers.

p – airproduction cross-section and uncorrelated mini-jets processes in pp-scattering

“…03002-p. 5 In this contribution, we have seen that the Glauber formula in conjunction with an inelastic pp cross-section obtained through a single-channel eikonal formalism provides a very good description of the cosmic ray extracted (p − air) cross-section. Thus, we might ask, whether a single-channel eikonal expression adequately representing the pp total cross-section is also sufficient to describe high energy elastic scattering.…”

Gluino air showers as a signal of split supersymmetry

“…As a result, the number of muons in a shower scales as E 0.94 . This in turn implies that the number of muons for a nucleus of mass A relates to the number of muons on a proton shower: [14]. At this point it is worth noting that these numbers are strongly dependent on the particular hadronic interaction model used.…”

“…The general properties of the longitudinal profile can be understood with a simple model and it usually can be parameterized by a Gaisser-Hillas function [14],…”

“…It is then possible to study the density of energy deposited (or particle densities), on the ground as a function of time and position. There are a number of parameterizations for such distributions but they are mostly modified power laws like the following [14] …”

Probing split supersymmetry with cosmic rays

“…In these showers, only high energy muons created in the first few generations of particles survive past 2 equivalent vertical atmospheres. The rate of energy attenuation for muons is much smaller than it is for electrons, thus the shape of the resulting shower front is very flat (with curvature radius above 100 km), and its time extension is very short (less than 50 ns) [18].…”