Measurement of meson resonance production in $$\pi ^-+$$ π - + C interactions at SPS energies

Abstract

We present measurements of ρ 0 , ω and K * 0 spectra in π − + C production interactions at 158 GeV/c and ρ 0 spectra at 350 GeV/c using the NA61/SHINE spectrometer at the CERN SPS. Spectra are presented as a function of the Feynman's variable x F in the range 0 < x F < 1 and 0 < x F < 0.5 for 158 and 350 GeV/c respectively. Furthermore, we show comparisons with previous measurements and predictions of several hadronic interaction models. These measurements are essential for a better understanding of hadronic shower development and for improving the modeling of cosmic ray air showers.

The hadronic interaction model Sibyll 2.3c and muon production in extensive air-showers

“…NA61 π − C with p Lab = 158 GeVc −NA61 π − C with p Lab = 158 GeVc −Feynman-x spectrum of neutral ρ-mesons in pioncarbon interactions as measured in the NA61 experiment[84]. This measurement confirms the enhancement of leading ρ 0 for nuclear targets.…”

High energy cosmic ray interactions and UHECR composition problem

“…[18], the dominance of the pion exchange mechanism has been postulated for forward meson production in nondiffractive pion-proton and pion-nucleus collisions, in order to reach an agreement with measured spectra of π 0 and ρ 0 mesons. While this conjecture has been further confirmed by the NA61 results on ρ 0 production in pion-carbon interactions [32], which are consistent with previous measurements for π + p collisions [39], the signatures of the very same mechanism are now clearly seen in the neutron spectra for pp collisions at LHC energies: at large Feynman x, LHCf observed a pronounced "bump" in the forward neutron spectra, corresponding to the pion exchange mechanism [37,38]. Thus, a consistent model implementation of the mechanism is an urgent task.…”

“…For cosmic ray applications, especially important is the treatment of forward hadron production in protonair and pion-air collisions. In this respect, one can benefit from recent results of the NA61 [32] and LHCf [33][34][35][36][37][38] experiments. In Ref.…”

Pseudorapidity dependence of multiplicity and transverse momentum fluctuations at the SPS energies

“…As shown in [27], the ratio of p and p produced in inelastic p+p collisions at the SPS energies changes significantly with the rapidity. Consequently, the baryo-chemical potential strongly 158 GeV/c depends on the pseudorapidity [28] and the choice of a pseudorapidity phase-space could probe different parts of the critical region on the phase diagram.…”