Precision measurement of net-proton-number gluctuations in Au+Au collisions at RHIC
We report precision measurements on cumulants (๐ถ๐) and factorial cumulants (๐ ๐) of (net) proton number distributions up to fourth order in Au+Au collisions over center-of-mass energies โ๐ ๐โข๐=7.7-27 GeV from phase II of the Beam Energy Scan program at RHIC. (Anti)protons are selected at midrapidity (...
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| Main Authors: | , , , , |
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| Corporate Author: | |
| Format: | Article (Journal) |
| Language: | English |
| Published: |
29 September 2025
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| In: |
Physical review letters
Year: 2025, Volume: 135, Issue: 14, Pages: 1-8 |
| ISSN: | 1079-7114 |
| DOI: | 10.1103/9l69-2d7p |
| Online Access: | Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1103/9l69-2d7p Verlag, lizenzpflichtig, Volltext: https://link.aps.org/doi/10.1103/9l69-2d7p |
| Author Notes: | STAR Collaboration* |
| Summary: | We report precision measurements on cumulants (๐ถ๐) and factorial cumulants (๐
๐) of (net) proton number distributions up to fourth order in Au+Au collisions over center-of-mass energies โ๐ ๐โข๐=7.7-27 GeV from phase II of the Beam Energy Scan program at RHIC. (Anti)protons are selected at midrapidity (|๐ฆ| <0.5) within a transverse momentum range of 0.4<๐๐<2.0 GeV/๐. Relative to various noncritical-point model calculations and peripheral collision 70%-80% data, the net proton ๐ถ4/๐ถ2 measurement in 0%-5% collisions shows a minimum around 19.6 GeV for significance of deviation at โผ2-5โข๐. A minimum in ๐ถ4/๐ถ2 with respect to a noncritical baseline is expected to be a characteristic feature of the signature associated with a critical point in the QCD phase diagram. In addition, deviations from noncritical baselines around the same collision energy region are also seen in proton factorial cumulant ratios, especially in ๐
2/๐
1 and ๐
3/๐
1. Dynamical model calculations including a critical point are called for in order to understand these precision measurements. |
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| Item Description: | Veroฬffentlicht: 29. September 2025 *STAR Collaboration: B.E. Aboona, I.M. Deppner, N. Herrmann, Y.H. Leung, Y. Soฬhngen [und 367 weitere Personen] Gesehen am 20.02.2026 |
| Physical Description: | Online Resource |
| ISSN: | 1079-7114 |
| DOI: | 10.1103/9l69-2d7p |