We report the production and azimuthal anisotropy measurements of strange and multi-strange hadrons at STAR BES energies. The $Λ/K^0_s$ ratio is reported at 3 GeV and observed to increase faster with transverse momentum than that at higher energies. The number-of-constituent quark (NCQ) scaling of $v_2$ has been studied at 19.6 GeV (BES-II). The NCQ scaling holds for particles and anti-particles, which can be considered as an evidence of partonic collectivity. The production of $K^{*0}$ resonance is also reported for 7.7-39 GeV (BES-I) and the $K^{*0}/K$ ratio suggests that hadronic re-scattering dominates over regeneration in central A+A collisions. Using the $K^{*0}/K$ ratio, we also report the lower limit of hadronic phase lifetime $( t_{kin} - t_{chem} )$.
In this proceedings, we have presented the invariant yield measurements of strange and multi strange hadrons such as $K^{0}_{S}$, $Λ$, $\barΛ$, $ϕ$, $Ξ^{-}$, $\barΞ^{+}$, $Ω^{-}$, $\barΩ^{+}$ in Au+Au collisions at $\sqrt{s_{NN}}$ = 54.4 GeV at midrapidity ($|y|<0.5$). The second and third-order azimuthal anisotropic flow of the above mentioned particles at $\sqrt{s_{NN}}$ = 27 and 54.4 GeV are also discussed. Some of the important observables such as nuclear modification factor ($R_{CP}$), baryon to meson ratio ($Ω/ϕ$), transverse momentum dependence of $v_{2}$ and $v_{3}$ are measured. The n…
In these proceedings, we present the second order ($v_{2}$) and the third order ($v_{3}$) azimuthal anisotropy measurements of strange and multi-strange hadrons such as $K^{0}_{S}$, $Λ$, $\barΛ$, $ϕ$, $Ξ^{-}$, $\barΞ^{+}$, $Ω^{-}$, $\barΩ^{+}$ in Au+Au collisions at $\sqrt{s_{NN}}$ = 27 and 54.4 GeV at STAR. The centrality dependence of $v_{2}$ and $v_{3}$ as well as the number of constituent quark scaling (NCQ scaling) for all the particles mentioned above are discussed. The ratio of $v_{2}$ of $ϕ$ mesons to that of $\bar{p}$ is presented at $\sqrt{s_{NN}}$ = 54.4 GeV which gives a hint of ma…
Heavy quarks are effective probes of the properties of the QGP created in ultra-relativistic heavy-ion collisions. The ALICE Collaboration measured the non-strange D-meson production in Pb--Pb collisions at $\sqrt{s_{\rm NN\,}}=5.02$ TeV. The in-medium energy loss can be studied via the nuclear modification factor measurement. The measurement of the D-meson elliptic flow, $v_2$, allows us to investigate the participation of the heavy quarks in the collective expansion of the system at low momentum and their possible thermalization in the medium. Furthermore, the Event-Shape Engineering techniq…
The elliptic azimuthal anisotropy coefficient ($v_2$) is measured for charm (D$^0$) and strange (K$_\mathrm{S}^0$, $Λ$, $Ξ^-$, and $Ω^-$) hadrons, using a data sample of pPb collisions collected by the CMS experiment, at a nucleon-nucleon center-of-mass energy $\sqrt{s_{_\mathrm{NN}}} =$ 8.16 TeV. A significant positive $v_2$ signal from long-range azimuthal correlations is observed for all particle species in high-multiplicity pPb collisions. The measurement represents the first observation of possible long-range collectivity for open heavy flavor hadrons in small systems. The results suggest…
An experimental overview of the energy dependence of strangeness production is presented. The strange hadrons are considered a good probe to study the QCD matter created in relativistic nucleus-nucleus collisions. The heavy-ion experiments at SPS, RHIC, and LHC have recorded a wealth of data in proton-proton, proton-nucleus and nucleus-nucleus collisions at several beam energies. In this proceeding, I discuss the invariant yield and azimuthal anisotropy measurement of strange hadrons in nucleus-nucleus collisions at SPS, RHIC, and LHC.
The production yield and angular anisotropy of prompt ${D_s^+}$ mesons were measured as a function of transverse momentum ($p_{ T}$) in Pb-Pb collisions at a centre-of-mass energy per nucleon pair $\sqrt{s_{ NN}} = 5.02$ TeV collected with the ALICE detector at the LHC. ${D_s^+}$ mesons and their charge conjugates were reconstructed at midrapidity ($|y|<0.5$) from their hadronic decay channel ${D_s^+ \to ϕπ^+}$, with ${ϕ\to K^-K^+}$, in the $p_{ T}$ intervals $2<p_{ T}<50$ GeV/$c$ and $2<p_{ T}<36$ GeV/$c$ for the 0-10% and 30-50% centrality intervals. For $p_{ T}>10$ GeV/$c$, the measured ${D…
The azimuthal anisotropy coefficient $v_2$ of prompt D$^0$, D$^+$, D$^{*+}$ and D$_s^+$ mesons was measured in mid-central (30-50% centrality class) Pb-Pb collisions at a centre-of-mass energy per nucleon pair $\sqrt{s_{\rm NN}} = 5.02$ TeV, with the ALICE detector at the LHC. The D mesons were reconstructed via their hadronic decays at mid-rapidity, $|y|<0.8$, in the transverse momentum interval $1<p_{\rm T}<24$ GeV/$c$. The measured D-meson $v_2$ has similar values as that of charged pions. The D$_s^+$ $v_2$, measured for the first time, is found to be compatible with that of non-strange D m…
In these proceedings, we report the elliptic ($v_{2}$) and triangular ($v_{3}$) flow measurements of strange and multi-strange hadrons such as $K_{S}^{0}$, ~$Λ$($\barΛ$), ~$ϕ$, ~$Ξ^{-}$($\barΞ^{+}$), and $Ω^{-}$($\barΩ^{+}$) at mid-rapidity ($|y| < 1.0$) in Au+Au collisions at $\sqrt{s_{NN}}$ = 19.6 GeV using high statistics Beam Energy Scan Phase-II (BES-II) data. The transverse momentum ($p_{T}$) dependence, centrality dependence, and the number of constituent quarks (NCQ) scaling of $v_{2}$ and $v_{3}$ are studied for all these particles. A better NCQ scaling is observed in the case of anti…
In these proceedings, we present the measurements of elliptic ($v_2$) and triangular ($v_3$) flow of (multi-)strange hadrons and $ϕ$ mesons in 19.6 and 14.6 GeV Au+Au collisions from STAR. The number of constituent quark (NCQ) scaling of $v_2$ and $v_3$ holds well at $\sqrt{ s_{\mathrm{ NN }} } $ = 19.6 GeV, which indicates the collective flow is built up in the partonic stage. At these energies, the anti-particles show better NCQ scaling than the particles for both $v_2$ and $v_3$, which may be caused by the different contributions from the produced and transported quarks.
Two-particle azimuthal correlations are measured with the ALICE apparatus in pp collisions at $\sqrt{s} = 13$ TeV to explore strangeness- and multiplicity-related effects in the fragmentation of jets and the transition regime between bulk and hard production, probed with the condition that a strange meson (K$^{0}_{\rm S}$) or baryon ($Λ$) with transverse momentum $p_{\rm T} > 3$ GeV/c is produced. Azimuthal correlations between kaons or $Λ$ hyperons with other hadrons are presented at midrapidity for a broad range of the trigger ($3 < p_{\rm T}^{\rm trigg} < 20$ GeV/$c$) and associated particl…
In these proceedings, we present the measurements of proton, light nuclei, and strange particle with neutral kaons correlation functions in Au+Au collisions at the BES program and top RHIC energy. The experimental results will be compared with model calculations to extract the size of emitting source and the properties of final state interactions. The collision energy and centrality dependence of the source size will be studied. Further, the implications for the production mechanism of light nuclei will be discussed.
Beauty quarks are considered as one of the best probes of the strongly interacting medium created in relativistic heavy-ion collisions because they are predominantly produced via initial hard scatterings. Our measurements of B mesons productions provide information on the diffusion of beauty quarks and the flavor dependence of in-medium energy loss. In these studies, clarifying the hadronization mechanism is crucial for understanding the transport properties of beauty quarks. We propose to show our experimental results on three sets of particles: nonprompt $J/ψ$ and $D^0$, $B^0_s$ and $B^+$, a…
Dark sector particles at the GeV scale carrying baryon number provide an attractive framework for understanding the origin of dark matter and the matter-antimatter asymmetry of the universe. We demonstrate that dark decays of hadronic states containing strange quarks -- hyperons -- offer excellent prospects for discovering such dark baryons. Building up on novel calculations of the matrix elements relevant for hyperon dark decays, and in view of various collider, flavor, and astrophysical constraints, we determine the expected rates at hyperon factories like BESIII and LHCb. We also highlight …
We perform the first simultaneous extraction of unpolarized parton distributions and fragmentation functions from a Monte Carlo analysis of inclusive and semi-inclusive deep-inelastic scattering, Drell-Yan lepton-pair production, and single-inclusive $e^+ e^-$ annihilation data. We use data resampling techniques to thoroughly explore the Bayesian posterior distribution of the extracted functions, and use $k$-means clustering on the parameter samples to identify the configurations that give the best description across all reactions. Inclusion of the semi-inclusive data reveals a strong suppress…
Medium-induced modification of azimuthal correlations of electrons from heavy-flavor hadron decays with charged particles in Pb--Pb collisions at $\sqrt{s_{\rm{NN}} = 5.02}$ TeV
EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH CERN（欧洲核子研究中心）
Angular correlations of heavy-flavour and charged particles in high-energy proton-proton collisions are sensitive to the production mechanisms of heavy quarks and to their fragmentation as well as hadronisation processes. The measurement of the azimuthal-correlation function of prompt D mesons with charged particles in proton-proton collisions at a centre-of-mass energy of $\sqrt{s} = 13$ TeV with the ALICE detector is reported, considering D$^{0}$, D$^{+}$, and D$^{*+}$ mesons in the transverse-momentum interval $3 < p_{\rm T} < 36$ GeV/$c$ at midrapidity ($|y| < 0.5$), and charged particles …
Inspired by the newly reported $Z_{cs}(3985)^{-}$ by the BESIII Collaboration, we systematically investigate the strange hidden-charm tetraquark systems $cs\bar{c}\bar{u}$ with two structures: meson-meson and diquark-antidiquark. Two quark models: the chiral quark model (ChQM) and the quark delocalization color screening model (QDCSM) are used here. Similar results are obtained in both two quark models. There is no any bound state in either ChQM or QDCSM, which excludes the molecular state explanation ($D_{s}D^{*}/D_{s}^{*}D/D_{s}^{*}D^{*}$) of the reported $Z_{cs}(3985)^{-}$. However, the eff…
