Precision measurement of net-proton-number gluctuations in Au+Au collisions at RHIC
We report precision measurements on cumulants (𝐶𝑛) and factorial cumulants (𝜅𝑛) of (net) proton number distributions up to fourth order in Au+Au collisions over center-of-mass energies √𝑠𝑁𝑁=7.7-27 GeV from phase II of the Beam Energy Scan program at RHIC. (Anti)protons are selected at midrapidity (...
Gespeichert in:
| Hauptverfasser: | , , , , |
|---|---|
| Körperschaft: | |
| Dokumenttyp: | Article (Journal) |
| Sprache: | Englisch |
| Veröffentlicht: |
29 September 2025
|
| In: |
Physical review letters
Year: 2025, Jahrgang: 135, Heft: 14, Pages: 1-8 |
| ISSN: | 1079-7114 |
| DOI: | 10.1103/9l69-2d7p |
| Online-Zugang: | Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1103/9l69-2d7p Verlag, lizenzpflichtig, Volltext: https://link.aps.org/doi/10.1103/9l69-2d7p |
| Verfasserangaben: | STAR Collaboration* |
| Zusammenfassung: | We report precision measurements on cumulants (𝐶𝑛) and factorial cumulants (𝜅𝑛) of (net) proton number distributions up to fourth order in Au+Au collisions over center-of-mass energies √𝑠𝑁𝑁=7.7-27 GeV from phase II of the Beam Energy Scan program at RHIC. (Anti)protons are selected at midrapidity (|𝑦| <0.5) within a transverse momentum range of 0.4<𝑝𝑇<2.0 GeV/𝑐. Relative to various noncritical-point model calculations and peripheral collision 70%-80% data, the net proton 𝐶4/𝐶2 measurement in 0%-5% collisions shows a minimum around 19.6 GeV for significance of deviation at ∼2-5𝜎. A minimum in 𝐶4/𝐶2 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 𝜅2/𝜅1 and 𝜅3/𝜅1. Dynamical model calculations including a critical point are called for in order to understand these precision measurements. |
|---|---|
| Beschreibung: | Veröffentlicht: 29. September 2025 *STAR Collaboration: B.E. Aboona, I.M. Deppner, N. Herrmann, Y.H. Leung, Y. Söhngen [und 367 weitere Personen] Gesehen am 20.02.2026 |
| Beschreibung: | Online Resource |
| ISSN: | 1079-7114 |
| DOI: | 10.1103/9l69-2d7p |