New strangeness measurements from STAR

Experimental data on inclusive cross sections of particles produced in high energy proton-(anti)proton collisions at ISR, RHIC, and Tevatron are analyzed in the framework of z-scaling. New features of the scaling function ψ(z) are established. These are flavor independence of ψ(z) including particles with heavy flavor content and saturation at low z. The flavor independence means that the shape of the scaling function ψ(z) is the same for different hadron species. The saturation corresponds to flattening of ψ(z) for z < 0.1. Relations of model parameters used in data z-presentation with some thermodynamical quantities (entropy, specific heat, temperature) are discussed. It is shown that behavior of the particle spectra at low z is controlled by a parameter c interpreted as a specific heat of the created medium associated with production of the inclusive particle. The saturation regime of ψ(z) observed at low z is assumed to be preferable in searching for phase transitions of hadron matter and for study of non-perturbative QCD in high energy proton-(anti)proton collisions at U70, RHIC, Tevatron, and LHC.

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“…The temperature T and the volume V characterize a state of the system. Using (22) and (23), we can write the relation…”

Section: A Variable Z and Entropymentioning

confidence: 99%

NEW PROPERTIES OF z-SCALING: FLAVOR INDEPENDENCE AND SATURATION AT LOW z

Zborovský

Tokarev

2009

Int. J. Mod. Phys. A

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“…Last we want to mention that in the case of nucleusnucleus collisions the existence of a strong collective radial flow (β coll ≈ 0.6 at RHIC [100]), absent in p+p collisions, changes the spectral shape of different hadrons produced at low transverse momenta (p T < ∼ 2 GeV/c) and should result in a violation of the m T -scaling behavior [101]. Because hydrodynamical flow results in a larger boost for the (heavier) η than for π 0 , one expects a comparatively larger R η/π 0 (p T ) ratio in Au+Au than in p+p collisions below p T ≈ 2 GeV/c.…”

Section: η/π 0 Ratio In Hadron-hadron Hadron-nucleus and Nuclear Comentioning

confidence: 99%

High transverse momentum η meson production inp+p,d+Au, and Au+Au collisions atsNN=
Adler¹,
Afanasiev²,
Aidala³
et al. 2007
Phys. Rev. C
90
8
37
0
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Inclusive transverse momentum spectra of η mesons in the range p T ≈ 2-12 GeV/c have been measured at midrapidity (|η| < 0.35) by the PHENIX experiment at RHIC in p+p, d+Au, and Au+Au collisions at √ s NN = 200 GeV. The η mesons are reconstructed through their η → γ γ channel for the three colliding systems as well as through the η → π 0 π + π − decay mode in p+p and d+Au collisions. The nuclear modification factor in d+Au collisions, R dAu (p T ) ≈ 1.0-1.1, suggests at most only modest p T broadening ("Cronin enhancement"). 024909-2HIGH TRANSVERSE MOMENTUM η MESON . . . PHYSICAL REVIEW C 75, 024909 (2007)

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“…The hyperons listed together with decay to with approximately 100% branching ratio, and so yield protons with the → pπ branching ratio. We estimate the proton and antiproton spectra from weak decays and subtract them from the measured yields, using experimental data from UA5 [26] from nonsingle diffractive √ s = 200 GeV p +p collisions, and preliminary and spectra from STAR in p + p and d + Au collisions at the same energy [27][28][29][30]. The shape of the 0 , 0 , and − spectra are constructed from the spectrum by m T scaling (i.e., under the assumption that these hadrons are all produced with roughly the same spectrum in transverse mass [30]).…”

Section: B Tracking and Particle Identificationmentioning

confidence: 99%

Nuclear effects on hadron production ind+Aucollisions atsNN
Adler¹,
Afanasiev²,
Aidala³
et al. 2006
Phys. Rev. C
95
3
24
0
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PHENIX has measured the centrality dependence of midrapidity pion, kaon, and proton transverse momentum distributions in d + Au and p + p collisions at √ s NN = 200 GeV. The p + p data provide a reference for nuclear effects in d + Au and previously measured Au + Au collisions. Hadron production is enhanced in d + Au, relative to independent nucleon-nucleon scattering, as was observed in lower energy collisions. The nuclear modification factor for (anti)protons is larger than that for pions. The difference increases with centrality but is not sufficient to account for the abundance of baryon production observed in central Au + Au collisions at the BNL Relativistic Heavy Ion Collider (RHIC). The centrality dependence in d + Au shows that the nuclear modification factor increases gradually with the number of collisions encountered by each participant nucleon. We also present comparisons with lower energy data as well as with parton recombination and other theoretical models of nuclear effects on particle production.

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New strangeness measurements from STAR

Cited by 17 publications

References 23 publications

NEW PROPERTIES OF z-SCALING: FLAVOR INDEPENDENCE AND SATURATION AT LOW z

NEW PROPERTIES OF z-SCALING: FLAVOR INDEPENDENCE AND SATURATION AT LOW z

High transverse momentum η meson production inp+p,d+Au, and Au+Au collisions atsNN=
Adler¹,
Afanasiev²,
Aidala³
et al. 2007
Phys. Rev. C
90
8
37
0
View full text Add to dashboard Cite

Nuclear effects on hadron production ind+Aucollisions atsNN
Adler¹,
Afanasiev²,
Aidala³
et al. 2006
Phys. Rev. C
95
3
24
0
View full text Add to dashboard Cite

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New strangeness measurements from STAR

Cited by 17 publications

References 23 publications

NEW PROPERTIES OF z-SCALING: FLAVOR INDEPENDENCE AND SATURATION AT LOW z

NEW PROPERTIES OF z-SCALING: FLAVOR INDEPENDENCE AND SATURATION AT LOW z

High transverse momentum η meson production inp+p,d+Au, and Au+Au collisions atsNN=Adler1, Afanasiev2, Aidala3 et al. 2007Phys. Rev. C908370View full textAdd to dashboardCite

Nuclear effects on hadron production ind+Aucollisions atsNNAdler1, Afanasiev2, Aidala3 et al. 2006Phys. Rev. C953240View full textAdd to dashboardCite

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High transverse momentum η meson production inp+p,d+Au, and Au+Au collisions atsNN=
Adler¹,
Afanasiev²,
Aidala³
et al. 2007
Phys. Rev. C
90
8
37
0
View full text Add to dashboard Cite

Nuclear effects on hadron production ind+Aucollisions atsNN
Adler¹,
Afanasiev²,
Aidala³
et al. 2006
Phys. Rev. C
95
3
24
0
View full text Add to dashboard Cite