Transverse momentum spectra of Lambda and K0Short particles are presented for Cu+Cu sqrt(s_NN) = 200 GeV collisions observed at STAR, and compared to Au+Au measurements at the same energy. For both systems, a number of observables are shown to increase at mid-rapidity (|y| < 0.5) with increasing centrality. These are the integrated Lambda and K0Short yields, the integrated Lambda and K0Short yields per participating nucleon, and mid-pT (1 GeV/c -> 4.5 GeV/c) Lambda/KK0Short ratios. The RCP ratio is found to be higher for the Lambda yields at mid-pT compared to the K0Short yields for both the Cu+Cu and Au+Au data. In contrast, when similar numbers of participating nucleons are considered for the Cu+Cu and Au+Au data, an indication of increased bulk strangeness production and a higher mid-pT (1 -> 4.5 GeV/c) Lambda/K0Short ratio are found, for Cu+Cu.
Systematic investigation of partonic collectivity through centrality dependence of elliptic flow of multi-strange hadrons in Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV in STAR
Multi-strange baryon elliptic flow in Au+Au collisions at sqrt(s_NN)= 200 GeV
本文报道了多奇异重子椭圆流$v_2(p_T)$的首次测量结果。多奇异重子的$Ξ+\bar{Xi}$和$Ω+\bar{Omega} in heavy-ion collisions. In minimum bias Au+Au collisions at sqrt(s_NN) = 200 GeV, a significant amount of elliptic flow, comparable to other non-strange baryons, is observed for multi-strange baryons which are expected to be particularly sensitive to the dynamics of the partonic stage of heavy-ion collisions. The $ p_T $ dependence of $ v_2$证实了以前在轻强子中观察到的组分夸克标度数。这些结果支持的想法，观察到的集体运动的相当大的一部分是在RHIC的超相对论性核碰撞的早期部分子阶段开发。
We report the elliptic flow ($v_{2}$) of $K_{s}^{0}$, $Λ$, $\barΛ$, $ϕ$, $Ξ^{-}$, and $\overlineΞ^{+}$ at mid-rapidity for Ru+Ru and Zr+Zr collisions at $\sqrt{s_{\mathrm {NN}}}$ = 200 GeV. The transverse momentum ($p_{T}$) and centrality dependence of $v_{2}$ have been studied. The number of constituent quark (NCQ) scaling for all the (multi-)strange hadrons has also been tested. The dependence in the ratio of average $v_{2}$ ($\langle$$v_{2}$$\rangle$) on centrality shows a deviation from unity indicating a difference in nuclear structure and deformation between the isobars. The results show…
We have studied the transverse momentum ($p_T$) spectra of the final-state strange particles, including $K^{\pm}$, $ϕ$, $\itΞ$, and $\itΩ$, produced in high energy lead-lead (Pb-Pb), proton-lead ($p$-Pb), xenon-xenon (Xe-Xe) collisions at the Large Hadron Collider (LHC). Taking into account the contribution of multi-quark composition, whose probability density distribution is described by the modified Tsallis-Pareto-type function, we simulate the $p_T$ spectra of the final-state strange particles by a Monte Carlo method, which is shown to be in good agreement with the experimental data in most…
We present a new method for detection of multiply charmed baryons via their decays into strange baryons, using `strangeness tracking'. This method makes use of the state-of-the-art upgraded silicon detectors in ALICE during Runs 3, 4 and beyond will enable the novel possibility of tracking strange hadrons directly before they decay, leading to a very significant improvement in impact-parameter resolution. In this work, we will discuss how this new technique will be crucial to distinguish secondary strange baryons originating from charm decays from primary strange baryons. This is a particularl…
Studying strangeness and baryon production mechanisms through angular correlations between charged $Ξ$ baryons and identified hadrons in pp collisions at $\sqrt{s}$ = 13 TeV
本文利用 ALICE 探测器在 $\sqrt{s}=13$ TeV pp 碰撞中测量带电 $Ξ$ 重子与已鉴别强子的角关联，研究了奇异性与重子产生机制，发现现有 Monte Carlo 模型均无法完全描述数据，为产生机制提供了严格约束。
The centrality dependence of the $p/π$ ratio measured by the ALICE Collaboration in 5.02 TeV Pb-Pb collisions indicates a statistically significant suppression with the increase of the charged particle multiplicity once the centrality-correlated part of the systematic uncertainty is eliminated from the data. We argue that this behavior can be attributed to baryon annihilation in the hadronic phase. By implementing the $B\bar{B} \leftrightarrow 5π$ reaction within a generalized partial chemical equilibrium framework, we estimate the annihilation freeze-out temperature at different centralities,…
The strange quark plays a unique role in QCD, reflecting its intermediate mass between the light and heavy quarks. In recent years, remarkable progress has been made in the spectroscopy of baryons with strangeness. Many new features of the strange baryon spectrum have been revealed by accurate experimental data with novel techniques, as well as systematic developments of theoretical framework to describe hadron resonances. The basic properties of strange baryons, namely, the pole positions, spin and parity, and decay branching ratios, are being determined accurately. As a consequence, the Part…
Although strange quarks are produced in $s\bar{s}$ pairs, the ratio of $Ω^{-}$ to ${\barΩ}^{+}$ is greater than one in heavy-ion collisions at lower RHIC energies. Thus the produced $Ω$ hyperons must carry net baryon quantum numbers from the colliding nuclei. We present results of $K$-$Ω$ correlations from AMPT model simulations of Au+Au collisions at $\sqrt{s_{NN}}$ = 14.6 GeV, to probe dynamics for baryon number transport to mid-rapidities at this beam energy. We use both the default and string-melting versions to illustrate how hadronization schemes of quark coalescence and string fragmenta…
Production of strange and charmed baryons in pion induced reactions
我们基于两种不同的理论框架：有效拉格朗日方法和Regge方法，研究了π介子束诱导的奇异和粲产生，即$π^-$ p $\rightarrow$ $K^{*0}Λ$和$π^-$ p $\rightarrow$ $D^{*-}Λ_c^+$反应.为了估计粲子产生相对于奇异度产生的大小，我们假设粲子和重子顶点的耦合常数与奇异度通道的耦合常数相同。我们发现，魅力生产的总截面约为$10^3 - 10^6$倍小于奇异生产，这取决于理论方法和运动学区域。我们还讨论了每一个贡献，这两个反应的观测。一般来说，Regge方法在整个能量区域内很好地解释了实验数据。
