Wed·Oct 22, 2025Wednesday·October 22, 2025

1. 01*

   Studies of jet quenching in O+O collisions at $\sqrt{s_{\mathrm{NN}}}$ = 200 GeV by STAR

   Sijie Zhang (for the STAR Collaboration)🇨🇳

   Jet quenching is a well-established probe of the QGP in large collision systems such as Au+Au and Pb+Pb, but is absent in smaller p+A collisions despite the presence of collectivity. This makes it important to study its dependence on system size. O+O collisions offer an ideal opportunity, bridging the gap between small and large systems. In these proceedings, we present the measurements of the following observables related to jet quenching: inclusive charged hadron $R_{\mathrm{AA}}$ and $R_{\mathrm{CP}}$ at high transverse momentum ($p_{\mathrm{T}}$), inclusive jet $R_{\mathrm{CP}}$, and semi-inclusive hadron+jet $I_{\mathrm{CP}}$, using O+O collisions data collected with the STAR detector in 2021 at $\sqrt{s_{\mathrm{NN}}}=200$ GeV. For jet measurements, combinatorial background is subtracted based on the event mixing technique, while background fluctuations and detector effects are corrected via unfolding. Inclusive charged hadron and jet $R_{\mathrm{CP}}$ and h+jet $I_{\mathrm{CP}}$ are found to be below unity, indicating suppression relative to peripheral events.

   nucl-exhep-exEPJ Web Conf.(2026)·2 citations
2. 02*

   Charm-strange meson production in relativistic heavy ion collisions

   Sungtae Cho🇰🇷 · Su Houng Lee🇰🇷

   We study charm-strange mesons, or $D_s$, $D_s^{\ast }$, $D_{s0}^{\ast }(2317)$, and $D_{s1}(2460)$ mesons by focusing on their production by coalescence from a quark-gluon plasma in relativistic heavy ion collisions at $\sqrt{s_{NN}}=5.02$ TeV. Starting from the investigation of the transverse momentum distribution of both charm and strange quarks through transverse momentum distributions of $\varphi$ and $D^0$ mesons, we calculate the transverse momentum distributions and yields of $D_s$, $D_s^{\ast }$, $D_{s0}^{\ast }(2317)$, and $D_{s1}(2460)$ mesons based on the coalescence model. We find that the yield and transverse momentum distribution of the $D_s$ meson agree well with the experimental measurements at $\sqrt{s_{NN}}=5.02$ TeV at LHC. We further evaluate the transverse momentum ratio between $D_s$ and $D^0$ mesons, and investigate the role of light and strange quarks in the production of charmed mesons in heavy ion collisions. Finally, we calculate the transverse momentum distribution and yield of the $D_{s0}^{\ast }(2317)$ meson in a four-quark state, and compare to those of $D_{s0}^{\ast }(2317)$ meson in a two-quark state.

   ↳ nucl-thhep-phnucl-ex2 citations
3. 03*

   Analysis note: measurement of thrust and track energy-energy correlator in $e^{+}{e}^{-}$ collisions at 91.2 GeV with DELPHI open data

   Jingyu Zhang🇺🇸 · Tzu-An Sheng🇺🇸 · Yu-Chen Chen🇺🇸 · Hannah Bossi🇺🇸 · Anthony Badea🇺🇸 · Austin Baty🇺🇸 · Chris McGinn🇺🇸 · Yen-Jie Lee🇺🇸 · Yi Chen🇺🇸

   Recent theoretical developments, as well as experimental measurements at hadron collisions, have renewed interest in studying event shape variables in $e^{+}{e}^{-}$ collisions. We present a measurement of thrust and track-based energy-energy correlator in $e^{+}{e}^{-}$ collisions at center-of-mass energy of 91.2 GeV, using newly released open data from the DELPHI experiment. The event shapes, measured with unprecedented resolution and precision, are compared to various Monte Carlo and analytic predictions. Leveraging DELPHI's unique detector geometry and reconstruction capabilities, the track energy-energy correlator measurement provides data with the highest angular resolution, offering critical inputs for precision tests of QCD in both collinear and back-to-back limits. This note presents the first physics analysis using DELPHI open data and establishes benchmarks necessary for future studies exploiting this legacy dataset.

   ↳ hep-exhep-phnucl-ex11 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.