Comprehensive results on the production of unidentified charged particles, π±, K±, K0S, K*(892)0, p, p¯¯¯, ϕ(1020), Λ, Λ¯¯¯¯, Ξ−, Ξ¯¯¯¯+, Ω− and Ω¯¯¯¯+ hadrons in proton-proton (pp) collisions at s√ = 7 TeV at midrapidity (|y|<0.5) as a function of charged-particle multiplicity density are presented. In order to avoid auto-correlation biases, the actual transverse momentum (pT) spectra of the particles under study and the event activity are measured in different rapidity windows. In the highest multiplicity class, the charged-particle density reaches about 3.5 times the value measured in inelastic collisions. While the yield of protons normalized to pions remains approximately constant as a function of multiplicity, the corresponding ratios of strange hadrons to pions show a significant enhancement that increases with increasing strangeness content. Furthermore, all identified particle to pion ratios are shown to depend solely on charged-particle multiplicity density, regardless of system type and collision energy. The evolution of the spectral shapes with multiplicity and hadron mass shows patterns that are similar to those observed in p-Pb and Pb-Pb collisions at LHC energies. The obtained pT distributions and yields are compared to expectations from QCD-based pp event generators as well as to predictions from thermal and hydrodynamic models. These comparisons indicate that traces of a collective, equilibrated system are already present in high-multiplicity pp collisions.
Eser Adı (dc.title) | Multiplicity dependence of light-flavor hadron production in pp collisions at √s = 7 TeV |
Yayın Türü (dc.type) | Makale |
Yazar/lar (dc.contributor.author) | KARASU UYSAL, Ayben |
Yazar/lar (dc.contributor.author) | ALICE Collaboration |
Atıf Dizini (dc.source.database) | Wos |
Atıf Dizini (dc.source.database) | Scopus |
Konu Başlıkları (dc.subject) | Light-Flavor Hadron Production |
Konu Başlıkları (dc.subject) | ALICE |
Konu Başlıkları (dc.subject) | LHC |
Yayın Tarihi (dc.date.issued) | 2019 |
Kayıt Giriş Tarihi (dc.date.accessioned) | 2019-07-08T09:26:12Z |
Açık Erişim tarihi (dc.date.available) | 2019-07-08T09:26:12Z |
Atıf için Künye (dc.identifier.citation) | 10.1103/PhysRevC.99.024906 |
Özet (dc.description.abstract) | Comprehensive results on the production of unidentified charged particles, π±, K±, K0S, K*(892)0, p, p¯¯¯, ϕ(1020), Λ, Λ¯¯¯¯, Ξ−, Ξ¯¯¯¯+, Ω− and Ω¯¯¯¯+ hadrons in proton-proton (pp) collisions at s√ = 7 TeV at midrapidity (|y|<0.5) as a function of charged-particle multiplicity density are presented. In order to avoid auto-correlation biases, the actual transverse momentum (pT) spectra of the particles under study and the event activity are measured in different rapidity windows. In the highest multiplicity class, the charged-particle density reaches about 3.5 times the value measured in inelastic collisions. While the yield of protons normalized to pions remains approximately constant as a function of multiplicity, the corresponding ratios of strange hadrons to pions show a significant enhancement that increases with increasing strangeness content. Furthermore, all identified particle to pion ratios are shown to depend solely on charged-particle multiplicity density, regardless of system type and collision energy. The evolution of the spectral shapes with multiplicity and hadron mass shows patterns that are similar to those observed in p-Pb and Pb-Pb collisions at LHC energies. The obtained pT distributions and yields are compared to expectations from QCD-based pp event generators as well as to predictions from thermal and hydrodynamic models. These comparisons indicate that traces of a collective, equilibrated system are already present in high-multiplicity pp collisions. |
Tek Biçim Adres (dc.identifier.uri) | https://hdl.handle.net/20.500.12498/672 |