Date

Observation of the Onset of Constituent Quark Number Scaling in Heavy-Ion Collisions at RHIC

The STAR collaboration Aboona, B.E. ; Adam, J. ; Adamczyk, L. ; et al.
Phys.Rev.Lett. 135 (2025) 072301, 2025.
Inspire Record 2907591 DOI 10.17182/hepdata.159489

Partonic collectivity is one of the necessary signatures for the formation of quark-gluon plasma in high-energy nuclear collisions. Number of constituent quarks (NCQ) scaling has been observed for hadron elliptic flow $v_2$ in top energy nuclear collisions at the Relativistic Heavy Ion Collider and the LHC, and this has been theoretically suggested as strong evidence for partonic collectivity. In this Letter, a systematic analysis of $v_2$ of $π^{\pm}$, $K^{\pm}$, $K^{0}_{S}$, $p$, and $Λ$ in Au+Au collisions at ${\sqrt{s_{_{\rm{NN}}}}}$ = 3.2, 3.5, 3.9, and 4.5 GeV, with the STAR experiment at the Relativistic Heavy Ion Collider, is presented. NCQ scaling is markedly violated at 3.2 GeV, consistent with a hadronic-interaction dominated equation of state. However, as the collision energy increases, a gradual evolution to NCQ scaling is observed. This beam-energy dependence of $v_2$ for all hadrons studied provides evidence for the onset of dominant partonic interactions by ${\sqrt{s_{_{\rm{NN}}}}}$ = 4.5 GeV.

72 data tables

$p_{T}$ dependence of $v_{2}$ for $\pi^{+}$ in Au+Au collisions at 3 GeV

$p_{T}$ dependence of $v_{2}$ for $\pi^{+}$ in Au+Au collisions at 3.2 GeV

$p_{T}$ dependence of $v_{2}$ for $\pi^{+}$ in Au+Au collisions at 3.5 GeV

More…

Flow and interferometry results from Au+Au collisions at $\sqrt{\textit{s}_{NN}}$ = 4.5 GeV

The STAR collaboration Adam, J. ; Adamczyk, L. ; Adams, J.R. ; et al.
Phys.Rev.C 103 (2021) 034908, 2021.
Inspire Record 1809043 DOI 10.17182/hepdata.95903

The Beam Energy Scan (BES) program at the Relativistic Heavy Ion Collider (RHIC) was extended to energies below $\sqrt{\textit{s}_{NN}}$ = 7.7 GeV in 2015 by successful implementation of the fixed-target mode of operation in the STAR (Solenoidal Track At RHIC) experiment. In the fixed-target mode, ions circulate in one ring of the collider and interact with a stationary target at the entrance of the STAR Time Projection Chamber. The first results for Au+Au collisions at $\sqrt{\textit{s}_{NN}}$ = 4.5 GeV are presented, including directed and elliptic flow of identified hadrons, and radii from pion femtoscopy. The proton flow and pion femtoscopy results agree quantitatively with earlier measurements by Alternating Gradient Synchrotron experiments at similar energies. This validates running the STAR experiment in the fixed-target configuration. Pion directed and elliptic flow are presented for the first time at this beam energy. Pion and proton elliptic flow show behavior which hints at constituent quark scaling, but large error bars preclude reliable conclusions. The ongoing second phase of BES (BES-II) will provide fixed-target data sets with 100 times more events at each of several energies down to $\sqrt{\textit{s}_{NN}}$ = 3.0 GeV.

12 data tables

Centrality selection for STAR FXT sqrt(sNN) = 4.5 GeV Au+Au collisions

Rapidity dependence of directed flow, v1(y), for protons with transverse momentum 0.4 < pT < 2.0 GeV/c from events with 10-25% centrality.

Rapidity dependence of directed flow, v1(y), for negative pions with transverse momentum pT > 0.2 GeV/c and total momentum magnitude |p| < 1.6 GeV/c from events within 10-30% centrality. Here, the BBC-based Event Plane method is used. Plotted error bars are statistical only, and systematic errors are of comparable size.

More…

Quasielastic Nucleon and Hyperon Production by Neutrinos and Anti-neutrinos With Energies Below 30-{GeV}

The SKAT collaboration Brunner, J. ; Grabosch, H.J. ; Kaufmann, H.H. ; et al.
Z.Phys.C 45 (1990) 551, 1990.
Inspire Record 26520 DOI 10.17182/hepdata.15281

The cross sections of neutrino and antineutrino quasielastic reactions\(vn \to \mu ^ -p,\bar vp \to \mu ^ +n,\bar vp \to \mu ^ +\Lambda\) were studied in the neutrino energy range between 3 and 30 GeV. In comparison withV-A theory axial mass parameters ofMA=(1.06±0.05±0.14) GeV/c2 from neutrino andMA=(0.71±0.10±0.20) GeV/c2 from antineutrino data were found. The total cross-section for the hyperon production process can be described byMA=1.0 GeV/c2.

1 data table

Measured Quasi-Elastic total cross section.


ANTI-NEUTRINO PRODUCTION OF CHARGED CHARMED VECTOR MESONS

Ammosov, V.V. ; Asratian, A.E. ; Burtovoy, V.S. ; et al.
JETP Lett. 45 (1987) 579-581, 1987.
Inspire Record 255622 DOI 10.17182/hepdata.12773

None

2 data tables

No description provided.

No description provided.


PRODUCTION OF F- MESONS IN ANTI-NEUTRINO N INTERACTIONS

Asratian, A.E. ; Gorichev, P.A. ; Kruchinin, S.P. ; et al.
JETP Lett. 46 (1987) 521-523, 1987.
Inspire Record 256218 DOI 10.17182/hepdata.40097

None

1 data table

No description provided.


Study of the Nucleon Structure Functions in Neutrino Interactions in the Energy Range of 10-{GeV} - 200-{GeV}

Ammosov, V.V. ; Burtovoy, V.S. ; Gapienko, V.A. ; et al.
Sov.J.Nucl.Phys. 47 (1988) 646, 1988.
Inspire Record 252538 DOI 10.17182/hepdata.17389

None

7 data tables

No description provided.

No description provided.

No description provided.

More…

STUDY OF POLARIZATION EFFECTS IN rho0 MESON PRODUCTION IN THE (ANTI)-NEUTRINO CHARGED CURRENT INDUCED QUARK JET

Ammosov, V.V. ; Burtovoy, V.S. ; Gapienko, V.A. ; et al.
Yad.Fiz. 46 (1987) 1673-1679, 1987.
Inspire Record 239544 DOI 10.17182/hepdata.40759

None

8 data tables

No description provided.

No description provided.

No description provided.

More…

Study of Quasielastic Reactions Neutrino $n \to \mu^- p$ and Anti-neutrino $p \to \mu^+ n$ in Bubble Chamber Skat at 3-{GeV} to 20-{GeV}

Grabosch, H.J. ; Kaufmann, K.K. ; Krecker, U. ; et al.
Sov.J.Nucl.Phys. 47 (1988) 1032-1034, 1988.
Inspire Record 239545 DOI 10.17182/hepdata.40876

None

4 data tables

No description provided.

No description provided.

No description provided.

More…

INCLUSIVE rho0 MESON PRODUCTIONS IN NEUTRINO INTERACTIONS AT SKAT CHAMBER

Ammosov, V.V. ; Ivanilov, A.A. ; Ivanov, P.V. ; et al.
IFVE-86-133, 1986.
Inspire Record 234594 DOI 10.17182/hepdata.10524

None

7 data tables

No description provided.

No description provided.

No description provided.

More…

Neutral Strange Particle Exclusive Production in Charged Current High-energy Anti-neutrino Interactions

Ammosov, V.V. ; Gapienko, V.A. ; Gapienko, G.S. ; et al.
Z.Phys.C 36 (1987) 377-381, 1987.
Inspire Record 230983 DOI 10.17182/hepdata.15702

The cross section of the quasi-elastic reactions\(\bar v_\mup \to \mu ^ +\Lambda (\Sigma ^0 )\) in the energy range 5–100 GeV is determined from Fermilab 15′ bubble chamber antineutrino data. TheQ2 analysis of quasi-elastic Λ events yieldsMA=1.0±0.3 GeV/c2 for the axial mass value. With zero µΛK0 events observed, the 90% confidence level upper limit\(\sigma (\bar v_\mup \to \mu ^ +\Lambda {\rm K}^0 )< 2.0 \cdot 10^{ - 40} cm^2 \) is obtained. At the same time, we found that the cross section of reaction\(\bar v_\mup \to \mu ^ +\Lambda {\rm K}^0+ m\pi ^0 \) is equal to\(\left( {3.9\begin{array}{*{20}c}{ + 1.6}\\{ - 1.3}\\ \end{array} } \right) \cdot 10^{ - 40} cm^2 \).

2 data tables

No description provided.

No description provided.