Ion Program of Na61/Shine at the CERN SPS

The NA61/SHINE experiment at the CERN SPS aims to discover the critical point of strongly interacting matter and study properties of the onset of deconfinement. These goals will be reached by measurements of hadron production properties in nucleus-nucleus, proton-proton and proton-lead interactions as a function of collision energy and size of the colliding nuclei. Furthermore, NA61/SHINE will perform numerous precision measurements needed for neutrino (T2K) and cosmic-ray (Pierre Auger Observatory and KASCADE) experiments. This paper summarizes physics arguments for the NA61/SHINE ion program and presents the status and plans of the experiment.Comment: 8 pages, 4 figures, invited talk at the SQM 2008, typos correcte

Measurement of Production Properties of Positively Charged Kaons in Proton-Carbon Interactions at 31 GeV/c

Spectra of positively charged kaons in p+C interactions at 31 GeV/c were measured with the NA61/SHINE spectrometer at the CERN SPS. The analysis is based on the full set of data collected in 2007 with a graphite target with a thickness of 4% of a nuclear interaction length. Interaction cross sections and charged pion spectra were already measured using the same set of data. These new measurements in combination with the published ones are required to improve predictions of the neutrino flux for the T2K long baseline neutrino oscillation experiment in Japan. In particular, the knowledge of kaon production is crucial for precisely predicting the intrinsic electron neutrino component and the high energy tail of the T2K beam. The results are presented as a function of laboratory momentum in 2 intervals of the laboratory polar angle covering the range from 20 up to 240 mrad. The kaon spectra are compared with predictions of several hadron production models. Using the published pion results and the new kaon data, the K+/\pi+ ratios are computed.Comment: 10 pages, 11 figure

Measurement of negatively charged pion spectra in inelastic p+p interactions at plabp_{lab} = 20, 31, 40, 80 and 158 GeV/c

We present experimental results on inclusive spectra and mean multiplicities of negatively charged pions produced in inelastic p+p interactions at incident projectile momenta of 20, 31, 40, 80 and 158 GeV/c ($\sqrt{s} =$ 6.3, 7.7, 8.8, 12.3 and 17.3 GeV, respectively). The measurements were performed using the large acceptance NA61/SHINE hadron spectrometer at the CERN Super Proton Synchrotron. Two-dimensional spectra are determined in terms of rapidity and transverse momentum. Their properties such as the width of rapidity distributions and the inverse slope parameter of transverse mass spectra are extracted and their collision energy dependences are presented. The results on inelastic p+p interactions are compared with the corresponding data on central Pb+Pb collisions measured by the NA49 experiment at the CERN SPS. The results presented in this paper are part of the NA61/SHINE ion program devoted to the study of the properties of the onset of deconfinement and search for the critical point of strongly interacting matter. They are required for interpretation of results on nucleus-nucleus and proton-nucleus collisions.Comment: Numerical results available at: https://edms.cern.ch/document/1314605 Updates in v3: Updated version, as accepted for publicatio

Multiplicity and transverse momentum fluctuations in inelastic proton-proton interactions at the CERN Super Proton Synchrotron

Measurements of multiplicity and transverse momentum fluctuations of charged particles were performed in inelastic p+p interactions at 20, 31, 40, 80 and 158 GeV/c beam momentum. Results for the scaled variance of the multiplicity distribution and for three strongly intensive measures of multiplicity and transverse momentum fluctuations \$\Delta[P_{T},N]\$, \$\Sigma[P_{T},N]\$ and \$\Phi_{p_T}\$ are presented. For the first time the results on fluctuations are fully corrected for experimental biases. The results on multiplicity and transverse momentum fluctuations significantly deviate from expectations for the independent particle production. They also depend on charges of selected hadrons. The string-resonance Monte Carlo models EPOS and UrQMD do not describe the data. The scaled variance of multiplicity fluctuations is significantly higher in inelastic p+p interactions than in central Pb+Pb collisions measured by NA49 at the same energy per nucleon. This is in qualitative disagreement with the predictions of the Wounded Nucleon Model. Within the statistical framework the enhanced multiplicity fluctuations in inelastic p+p interactions can be interpreted as due to event-by-event fluctuations of the fireball energy and/or volume.Comment: 18 pages, 12 figure

Two-particle correlations in azimuthal angle and pseudorapidity in inelastic p + p interactions at the CERN Super Proton Synchrotron

Results on two-particle ΔηΔϕ correlations in inelastic p + p interactions at 20, 31, 40, 80, and 158 GeV/c are presented. The measurements were performed using the large acceptance NA61/SHINE hadron spectrometer at the CERN Super Proton Synchrotron. The data show structures which can be attributed mainly to effects of resonance decays, momentum conservation, and quantum statistics. The results are compared with the Epos and UrQMD models

Recent results from proton intermittency analysis in nucleus–nucleus collisions from NA61 at CERN SPS

The search for experimental signatures of the critical point (CP) of strongly interacting matter is one of the main objectives of the NA61/SHINE experiment at CERN SPS. In the course of the experiment, an energy (beam momentum 13A–150A GeV/c) and system size (p+p, p+Pb, Be+Be, Ar+Sc, Xe+La) scan is performed. Local proton density fluctuations in transverse momentum space represent an order parameter of the chiral phase transition and are expected to scale according to a universal power-law in the vicinity of the CP; we probe their behaviour through an intermittency analysis of the proton second scaled factorial moments (SSFMs) in transverse momentum space. Previous such analyses revealed power-law behaviour in NA49 “Si”+Si collisions at 158A GeV/c; no intermittency was observed in NA49 “C”+C and Pb+Pb collisions at the same energy, and in NA61/SHINE Be+Be collisions at 150A GeV/c. Results suggest a baryochemical potential for the critical point in the vicinity of ∼ 250 MeV. In the present work, we extend the analysis to the NA61/SHINE Ar+Sc system at 150A GeV/c. We employ statistical techniques to subtract non-critical background and estimate statistical and systematic uncertainties. Finally, we use Monte Carlo simulations to estimate the likelihood of a spurious signal. © 2019 Jagellonian University. All rights reserved

Idempotents dans les algebres de Clifford et fibrations spinorielles amorphes

SIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Measurements of production properties of K-S(0) mesons and Lambda hyperons in proton- carbon interactions at 31 GeV/c

Spectra of K-S(0) mesons and Lambda hyperons were measured in p + C interactions at 31 GeV/c with the large acceptance NA61/SHINE spectrometer at the CERN SPS. The data were collected with an isotropic graphite target with a thickness of 4% of a nuclear interaction length. Interaction cross sections, charged pion spectra, and charged kaon spectra were previously measured using the same data set. Results on K-S(0) and Lambda production in p + C interactions serve as a reference for the understanding of the enhancement of strangeness production in nucleus-nucleus collisions. Moreover, they provide important input for the improvement of neutrino flux predictions for the T2K long baseline neutrino oscillation experiment in Japan. Inclusive production cross sections for K-S(0) and Lambda are presented as a function of laboratory momentum in intervals of the laboratory polar angle covering the range from 0 up to 240 mrad. The results are compared with predictions of several hadron production models. The K-S(0) mean multiplicity in production processes < n(KS0)> and the inclusive cross section for K-S(0) production sigma(KS0) were measured and amount to 0.127 +/- 0.005 (stat) +/- 0.022 (sys) and 29.0 +/- 1.6 (stat) +/- 5.0 (sys) mb, respectively

Production of Lambda-hyperons in inelastic p plus p interactions at 158 GeV/c

Inclusive production of Lambda-hyperons was measured with the large acceptance NA61/SHINE spectrometer at the CERN SPS in inelastic p+p interactions at beam momentum of 158 GeV/c. Spectra of transverse momentum and transverse mass as well as distributions of rapidity and x(F) are presented. The mean multiplicity was estimated to be 0.120+/-0.006 (stat.) +/-0.010 (sys.). The results are compared with previous measurements and predictions of the EPOS, URQMD and FRITIOF models