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1. Measurement of charged hadron multiplicity in Au+Au collisions at $$ \sqrt{{\textrm{s}}_{\textrm{NN}}} $$ = 200 GeV with the sPHENIX detector

   https://doi.org/10.1007/JHEP08(2025)075  

   Abdulhamid, M I; Acharya, U; Adams, E R; Adawi, G; Aidala, C A; Akiba, Y; Alfred, M; Ali, S; Alsayegh, A; Altaf, S; et al (August 2025, Journal of High Energy Physics)

   A<sc>bstract</sc> The pseudorapidity distribution of charged hadrons produced in Au+Au collisions at a center-of-mass energy of$$ \sqrt{{\textrm{s}}_{\textrm{NN}}} $$ $\sqrt{s_{\mathrm{NN}}}$ = 200 GeV is measured using data collected by the sPHENIX detector. Charged hadron yields are extracted by counting cluster pairs in the inner and outer layers of the Intermediate Silicon Tracker, with corrections applied for detector acceptance, reconstruction efficiency, combinatorial pairs, and contributions from secondary decays. The measured distributions cover |η|<1.1 across various centralities, and the average pseudorapidity density of charged hadrons at mid-rapidity is compared to predictions from Monte Carlo heavy-ion event generators. This result, featuring full azimuthal coverage at mid-rapidity, is consistent with previous experimental measurements at the Relativistic Heavy Ion Collider, thereby supporting the broader sPHENIX physics program. 

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2. Strangeness production in $$ \sqrt{s_{\textrm{NN}}} $$ = 3 GeV Au+Au collisions at RHIC

   https://doi.org/10.1007/JHEP10(2024)139  

   Abdulhamid, M I; Aboona, B E; Adam, J; Adamczyk, L; Adams, J R; Aggarwal, I; Aggarwal, M M; Ahammed, Z; Aschenauer, E C; Aslam, S; et al (October 2024, Journal of High Energy Physics)

   A<sc>bstract</sc> We report multi-differential measurements of strange hadron production ranging from mid- to target-rapidity in Au+Au collisions at a center-of-momentum energy per nucleon pair of$$ \sqrt{s_{\textrm{NN}}} $$ $\sqrt{s_{\mathrm{NN}}}$ = 3 GeV with the STAR experiment at RHIC.$$ {K}_S^0 $$ $K_S^0$ meson and Λ hyperon yields are measured via their weak decay channels. Collision centrality and rapidity dependences of the transverse momentum spectra and particle ratios are presented. Particle mass and centrality dependence of the average transverse momenta of Λ and$$ {K}_S^0 $$ $K_S^0$ are compared with other strange particles, providing evidence of the development of hadronic rescattering in such collisions. The 4πyields of each of these strange hadrons show a consistent centrality dependence. Discussions on radial flow, the strange hadron production mechanism, and properties of the medium created in such collisions are presented together with results from hadronic transport and thermal model calculations. 

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3. Inclusive and multiplicity dependent production of electrons from heavy-flavour hadron decays in pp and p-Pb collisions

   https://doi.org/10.1007/JHEP08(2023)006  

   Acharya, S.; Adamová, D.; Adler, A.; Aglieri Rinella, G.; Agnello, M.; Agrawal, N.; Ahammed, Z.; Ahmad, S.; Ahn, S. U.; Ahuja, I.; et al (August 2023, Journal of High Energy Physics)

   A<sc>bstract</sc> Measurements of the production of electrons from heavy-flavour hadron decays in pp collisions at$$ \sqrt{s} $$ $\sqrt{s}$ = 13 TeV at midrapidity with the ALICE detector are presented down to a transverse momentum (p_T) of 0.2 GeV/cand up top_T= 35 GeV/c, which is the largest momentum range probed for inclusive electron measurements in ALICE. In p-Pb collisions, the production cross section and the nuclear modification factor of electrons from heavy-flavour hadron decays are measured in thep_Trange 0.5< p_T<26 GeV/cat$$ \sqrt{s_{\textrm{NN}}} $$ $\sqrt{s_{\mathrm{NN}}}$ = 8.16 TeV. The nuclear modification factor is found to be consistent with unity within the statistical and systematic uncertainties. In both collision systems, first measurements of the yields of electrons from heavy-flavour hadron decays in different multiplicity intervals normalised to the multiplicity-integrated yield (self-normalised yield) at midrapidity are reported as a function of the self-normalised charged-particle multiplicity estimated at midrapidity. The self-normalised yields in pp and p-Pb collisions grow faster than linear with the self-normalised multiplicity. A strongp_Tdependence is observed in pp collisions, where the yield of high-p_Telectrons increases faster as a function of multiplicity than the one of low-p_Telectrons. The measurement in p-Pb collisions shows nop_Tdependence within uncertainties. The self-normalised yields in pp and p-Pb collisions are compared with measurements of other heavy-flavour, light-flavour, and strange particles, and with Monte Carlo simulations. 

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4. Strange hadron collectivity in pPb and PbPb collisions

   https://doi.org/10.1007/JHEP05(2023)007  

   Tumasyan, A.; Adam, W.; Andrejkovic, J. W.; Bergauer, T.; Chatterjee, S.; Dragicevic, M.; Escalante Del Valle, A.; Frühwirth, R.; Jeitler, M.; Krammer, N.; et al (May 2023, Journal of High Energy Physics)

   A<sc>bstract</sc> The collective behavior of$$ {\textrm{K}}_{\textrm{S}}^0 $$ $K_S^0$ and$$ \Lambda /\overline{\Lambda} $$ $\Lambda /\overline{\Lambda }$ strange hadrons is studied by measuring the elliptic azimuthal anisotropy (v₂) using the scalar-product and multiparticle correlation methods. Proton-lead (pPb) collisions at a nucleon-nucleon center-of-mass energy$$ \sqrt{s_{\textrm{NN}}} $$ $\sqrt{s_{\mathrm{NN}}}$ = 8.16 TeV and lead-lead (PbPb) collisions at$$ \sqrt{s_{\textrm{NN}}} $$ $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV collected by the CMS experiment at the LHC are investigated. Nonflow effects in the pPb collisions are studied by using a subevent cumulant analysis and by excluding events where a jet with transverse momentum greater than 20 GeV is present. The strange hadronv₂values extracted in pPb collisions via the four- and six-particle correlation method are found to be nearly identical, suggesting the collective behavior. Comparisons of the pPb and PbPb results for both strange hadrons and charged particles illustrate how event-by-event flow fluctuations depend on the system size. 

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5. Medium-induced modification of azimuthal correlations of electrons from heavy-flavor hadron decays with charged particles in Pb–Pb collisions at $$\mathbf {\sqrt{s_{\textrm{NN}}} = 5.02}$$ TeV

   https://doi.org/10.1140/epjc/s10052-026-15412-w  

   Abualrob, I J; Acharya, S; Aglieri_Rinella, G; Aglietta, L; Agnello, M; Agrawal, N; Ahammed, Z; Ahmad, S; Ahuja, I; Akbar, Z; et al (June 2026, The European Physical Journal C)

   Abstract The azimuthal-correlation distributions between electrons from the decays of heavy-flavor hadrons and associated charged particles in Pb–Pb collisions at$$\sqrt{s_{\textrm{NN}}} = 5.02$$ $\sqrt{s_{\text{NN}}}=5.02$ TeV are reported for the 0–10% and 30–50% centrality classes. This measurement provides access to the jet-like correlation observables in the heavy-flavor sector in Pb–Pb collisions. The analysis is performed for trigger electrons from heavy-flavor hadron decays with transverse momentum$$4< p_\textrm{T}^\textrm{e} < 16~\textrm{GeV}/c$$ $4<p_{\text{T}}^{\text{e}}<16\text{GeV}/c$ , considering associated particles within the transverse-momentum range$$1< p_\textrm{T}^\textrm{assoc} < 7$$ $1<p_{\text{T}}^{\text{assoc}}<7$ $$\textrm{GeV}/c$$ $\text{GeV}/c$ , and a pseudorapidity difference of$$|\Delta \eta |<1$$ $\left|\Delta \eta \right|<1$ between the trigger electron and associated particles. The per-trigger nuclear modification factor ($$I_\textrm{AA}$$ $I_{\text{AA}}$ ) is calculated to compare the near- and away-side peak yields to those in pp collisions at$$\sqrt{s} = 5.02$$ $\sqrt{s}=5.02$ TeV. In 0–10% central collisions, the$$I_\textrm{AA}$$ $I_{\text{AA}}$ indicates a hint of enhancement of associated-particle yields with$$p_\textrm{T}<3$$ $p_{\text{T}}<3$ GeV/con the near side, and a suppression of yields with$$p_\textrm{T}>4$$ $p_{\text{T}}>4$ GeV/con the away side. The$$I_\textrm{AA}$$ $I_{\text{AA}}$ for electron triggers from heavy-flavor hadron decays is compared with that for light-flavor and strange-particle triggers to investigate the dependence on different fragmentation processes and parton-medium dynamics, and is found to be the same within uncertainties. 

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