LHCb: Recent results related to cosmic ray interactions

H.-P Dembinski

doi:10.1051/epjconf/201920815005

Abstract

The LHCb experiment is designed to study flavor physics of b and c quarks. The detector is optimized for the study of identified hadrons produced in the forward direction, which also makes LHCb very interesting for the understanding of cosmic-ray induced air showers. LHCb is analysing proton-proton, protonlead, and lead-lead collisions. As a unique feature, LHCb is also studying beam interactions with noble gases using its SMOG system. We present recent measurements of charmed mesons, which are used to obtain production cross-sections, to constrain the parton PDF, to test pomeron and multi-particle interactions, nuclear and collective effects. These mostly have an indirect impact on the modeling of hadronic interactions. Finally, we present a direct measurement of the anti-proton production in proton collisions with helium gas, which are important for the understanding of AMS-02 and PAMELA data.

Highlights

The LHCb experiment [1] is a forward spectrometer fully instrumented in pseudo-rapidity 2 < η < 5
The acceptance of LHCb has been recently enhanced with HeRSCHeL [3], a system of forward scintillators up- and downstream of LHCb, to detect scattered charged particles in the pseudo-rapidity range 5 < |η| < 10
A hint of such a ridge seems to be present in events with high activity in the detector, but a full experimental analysis is in order to quantify the effect in the unique forward acceptance

Summary

Introduction

The LHCb experiment [1] is a forward spectrometer fully instrumented in pseudo-rapidity 2 < η < 5. LHCb has very good momentum and vertex resolution and is the only main LHC experiment with hadron identification capabilities in the forward rapidity range, provided by its system of two ring-imaging Cherenkov (RICH) detectors [2]. The acceptance of LHCb has been recently enhanced with HeRSCHeL [3], a system of forward scintillators up- and downstream of LHCb, to detect scattered charged particles in the pseudo-rapidity range 5 < |η| < 10. We highlight recent measurements by LHCb with a relevance for air showers. Many of these provide indirect insights, by revealing details of pomeron and multiparticle interactions and of nuclear effects in protonnucleus interactions, but there are direct measurements like the inelastic cross-section, the production cross-sections for charmed mesons and anti-protons. We close with a brief discussion of possible future measurements

Proton-proton collisions

Proton-lead collisions

Proton collisions with helium and argon gas

Prospects of future LHCb measurements for cosmic-ray research