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

A Aduszkiewicz,K Kowalik,A Korzenev,O Wyszyński,R Sarnecki,H Ströbele,P Staszel,M Nirkko,A Bravar,A Haesler,C Pistillo,J Dumarchez,B Baatar,M Bogomilov,E Rondio,A Grzeszczuk,T Matulewicz,J Puzović,K Nishikawa,M Pavin,A Ivashkin,R Płaneta,T Hasegawa,B Maksiak,Z Fodor,M Naskręt,M Vassiliou,D Kolev,G Stefanek,A Sadovsky,D Tefelski,A Wilczek,A Marcinek,E Kaptur,P Seyboth,M Kuich,A Rustamov,R Tsenov,N Davis,D Manić,J Brzychczyk,M Maćkowiak-Pawłowska,M Unger,M Szuba,O Petukhov,K Dynowski,K Sakashita,O Busygina,T Kobayashi,S Puławski,F Bay,W Dominik,A Redij,M Ravonel,M Shibata,A Blondel,G L Melkumov,A Tefelska,T Nakadaira,M Hierholzer,J Blümer,R Engel,L Zambelli,A E Hervé ,V Matveev,A Krasnoperov,M Rybczyński ,M Kozieł ,S Mrówczyński,E Richter-Wąs ,Y Ali,Г Феофилов ,V Kondratiev ,M Roth,D Röhrich,L Vinogradov,A Kurepin,G Vesztergombi,S Kowalski,Á László ,В И Колесников ,A Wojtaszek-Szwarć ,T Sekiguchi,S.a Bunyatov ,J Steṕaniak ,V Lyubushkin ,A Robert,R Renfordt,S N Igolkin ,A S Kapoyannis ,T Antičić ,F Guber,D Sgalaberna,Evgeny Andronov ,K Grebieszkow,M Gaździcki,L Turko,H.-P Dembinski ,A Rubbia,M Tada,A Malakhov ,S V Morozov ,T Czopowicz,P Christakoglou,K Márton ,A Panagiotou ,Maciej Piotr Lewicki ,J Kisiel,M Deveaux,M Słodkowski,А А Гарибов ,K Kadija,T Šuša,Б Popov ,S Débieux ,S Di Luise ,M Posiadała,N G Antoniou ,M Ćirković ,A Yu Seryakov ,M Golubeva,W Rauch,R Ulrich,H J Mathes ,D Veberič,V Vechernin ,D Larsen,K Schmidt,A Ereditato,F Κ Diakonos ,Z Włodarczyk ,В Терещенко

doi:10.1140/epjc/s10052-016-4450-9

Abstract

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.

Highlights

Introduction and motivationThis paper presents experimental results on event-by-event fluctuations of multiplicities and transverse momenta of charged particles produced in inelastic p+p interactions at 20, 31, 40, 80 and 158 GeV/c
The results shown refer to primary accepted hadrons produced in all inelastic p+p interactions
This paper presents measurements of multiplicity and transverse momentum fluctuations of negatively, positively and all charged hadrons produced in inelastic p+p interactions at 20, 31, 40, 80 and 158 GeV/c beam momentum

Summary

Introduction

Introduction and motivationThis paper presents experimental results on event-by-event fluctuations of multiplicities and transverse momenta of charged particles produced in inelastic p+p interactions at 20, 31, 40, 80 and 158 GeV/c. The measurements were performed by the multi-purpose NA61/SHINE [1,2] experiment at the CERN Super Proton Synchrotron (SPS). They are part of the strong interaction program devoted to the study of the properties of the onset of deconfinement and search for the critical point of strongly interacting matter. Within this program a two-dimensional scan in collision energy and size of colliding nuclei is in progress. The expected signal of a critical point is a non-monotonic dependence of various fluctuation measures in such a scan, for recent review see Ref. [3]

Methods

Results

Conclusion