System size dependence of hadron production properties is discussed within the Wounded Nucleon Model and the Statistical Model in the grand canonical, canonical and micro-canonical formulations. Similarities and differences between predictions of the models related to the treatment of conservation laws are exposed. A need for models which would combine a hydrodynamical-like expansion with conservation laws obeyed in individual collisions is stressed.
This article is focused on the multiplicity and probability distribution of the emitted charged pions <N_π> for interaction of ^{84}Kr_{36} projectile with nuclear emulsion targets at kinetic energy 1 GeV per nucleon. In the wounded nucleon model frame work, we have calculated the total number of wounded nucleons (W) and total number of interactions (ν). The obtained results revealed that the average multiplicity of the charged pions <N_π> is dependent on the projectile and target mass. The calculated values of the wounded nucleons (W) and total number of interactions (ν) shows strong dependen…
We study the effect of the nucleon meson cloud on predictions of the Monte Carlo Glauber wounded nucleon model for $AA$, $pA$, and $pp$ collisions. From the analysis of the data on the charged multiplicity density in $AA$ collisions we find that the meson-baryon Fock component reduces the required fraction of binary collisions by a factor of $\sim 2$ for Au+Au collisions at $\sqrt{s}=0.2$ TeV and $\sim 1.5$ for Pb+Pb collisions at $\sqrt{s}=2.76$ TeV. For central $AA$ collisions the meson cloud can increase the multiplicity density by $\sim 16-18$\%. We give predictions for the midrapidity cha…
A model in which the soft collisions of the nucleon are described in terms of interactions of its two constituents (a quark and a diquark) is proposed. When adjusted to describe precisely the elastic proton-proton scattering data and supplemented with the idea of wounded constituents, the model accounts rather well for the centrality dependence of particle production in the central rapidity region at RHIC energies.
Using the wounded nucleon, quark, and quark-diquark models, we extract the wounded source emission functions from the PHOBOS data for d+Au collisions at $\sqrt{s_{_{NN}}}=200$ GeV. We apply these models to compute charged particle multiplicity distributions as functions of pseudorapidity for p+p, p+Al, p+Au, d+Au, $^3$He+Au, Cu+Cu, Cu+Au, Au+Au, and U+U collisions at the same energy and compare them with experimental data from the PHOBOS and PHENIX collaborations. In symmetric collisions of heavy nuclei, the obtained distributions differ among the tested models. On the other hand, in asymmetri…
The wounded nucleon and quark emission functions are extracted for different centralities in d+Au collisions at $\sqrt{s}=200\ \text{GeV}$ using Monte Carlo simulations and experimental data. The shape of the emission function depends on centrality in the wounded nucleon model, whereas it is practically universal (within uncertainties) in the wounded quark model. Predictions for $dN_{ch}/dη$ distributions in p+Au and $^3$He+Au collisions are presented.
We analyze the phenomenon of size-flow transmutation in ultrarelativistic nuclear collisions in a model where the initial size fluctuations are driven by the wounded quarks and the collectivity is provided by viscous hydrodynamics. It is found that the model properly reproduces the data for the transverse momentum fluctuations measured for Pb+Pb collisions at 2.76TeV by the ALICE Collaboration. The agreement holds for a remarkably wide range of centralities, from 0-5% up to 70-80%, and displays a departure from a simple scaling with $(dN_{\rm ch}/dη)^{1/2}$ in the form seen in the data. The ov…
We discuss multiplicity fluctuations of charged particles produced in nuclear collisions measured event-by-event by the NA49 experiment at CERN SPS within the Glauber Monte Carlo approach. We use the concepts of wounded nucleons and wounded quarks in the mechanism of multiparticle production to characterize multiplicity fluctuations expressed by the scaled variance of multiplicity distribution. Although Wounded Nucleon Model correctly reproduce the centrality dependence of the average multiplicity in Pb+Pb collisions, it completely fails in description of corresponding centrality dependence of…
We formulate a baseline model for the net-proton number fluctuations in ultrarelativistic heavy-ion collisions. Our model includes total baryon number conservation, fluctuations of the participating nucleon number, limited acceptance, and a possibility that isospin is remembered by the participating wounded nucleons. Most importantly, we formulated the model as consisting of two components: wounded nucleons and the produced nucleon-antinucleon pairs. Those two components have different rapidity distributions. Owing to this feature we obtain also predictions for the rapidity dependence of the c…
Wounded parton scaling of multiplicities in ultra-relativistic light- and heavy-ion collisions
Institute of Nuclear Physics, Polish Academy of Sciences（波兰科学院核物理研究所）；AGH University of Kraków, Faculty of Physics and Applied Computer Science（克拉科夫AGH科技大学物理与应用计算机科学学院）
We compare the subtractive renormalization and the Wilsonian renormalization group approaches in the context of an effective field theory for the two-nucleon system. Based on an exactly solvable model of contact interactions, we observe that the standard Wilsonian renormalization group approach with a single cutoff parameter does not cover the whole space spanned by the renormalization scale parameters of the subtractive formalism. In particular, renormalization schemes corresponding to Weinberg's power counting in the case of an unnaturally large scattering length are beyond the region covere…
Initial state anisotropies in ultrarelativistic heavy-ion collisions from the Monte Carlo Glauber model
在重离子碰撞的流体动力学模拟中，初始态的空间各向异性转化为末态粒子分布的动量各向异性。因此，理解初始各向异性的起源和量化它们的不确定性对于从实验数据中提取特定的QCD物质性质（如粘度）非常重要。在这项工作中，我们研究了受伤的核子的方法在Monte Carlo Glauber模型的框架，特别关注的不确定性所产生的碰撞核子对之间的核子-核子相互作用和碰撞核内的核子-核子关联的建模。我们比较了黑盘模型和概率轮廓函数方法的非弹性核子核子相互作用，并研究了初始状态的相关性，使用这些国家的最先进的建模的影响。
Initial state anisotropies and their uncertainties in ultrarelativistic heavy-ion collisions from the Monte Carlo Glauber model
在重离子碰撞的流体动力学模拟中，初始态的空间各向异性被转化为末态粒子分布的动量各向异性。因此，在从实验数据中提取特定的QCD物质性质（如粘度）之前，理解初始态各向异性及其不确定性的起源是很重要的。在这项工作中，我们回顾了受伤的核子的方法的基础上的Monte Carlo Glauber模型，特别是图表的不确定性所产生的碰撞核子对和碰撞核内的核子-核子相关性之间的核子-核子相互作用的建模。我们讨论了非弹性核子-核子相互作用的黑盘模型和概率分布函数方法之间的差异，并研究了初始状态相关性的影响，使用国家的最先进的建模这些。
We explore Glauber Monte Carlo predictions for the planned ultra-relativistic ${}^{16}{\rm O}$+${}^{16}{\rm O}$ and p+${}^{16}{\rm O}$ collisions, as well as for collisions of ${}^{16}{\rm O}$ on heavy targets. In particular, we present specific collective flow measures which are approximately independent on the hydrodynamic response of the system, such as the ratios of eccentricities obtained from cumulants with different numbers of particles, or correlations of ellipticity and triangularity described by the normalized symmetric cumulants. We use the state-of-the-art correlated nuclear distri…
The $λ$ and $m_{ββ}$ mechanisms of neutrinoless double beta decay ($0νββ$) occur with light neutrino exchange via $W_L-W_R$, and $W_L-W_L$ mediation, respectively. In the present study, we calculate the nuclear matrix elements (NMEs) for the $m_{ββ}$ and $λ$ mechanisms of $0νββ$, which has origin in the left-right symmetric model with right-handed gauge boson at TeV scale. The NMEs are calculated for one of the $0νββ$ decaying isotope $^{48}$Ca in the interacting nuclear shell-model using the GXPF1A effective interaction of $pf$-shell. The NMEs are calculated in both closure and nonclosure app…
The standard way to demonstrate the relevance of chiral symmetry for the NN interaction is to consider higher partial waves of NN scattering which are controlled entirely by chiral pion-exchanges (since contacts vanish). However, in applications of NN-potentials to nuclear structure and reactions, the lower partial waves are the important ones, making the largest contributions. Lower partial waves are sensitive to the short-range potential, and so, when the short-range contacts were to dominate over the chiral pion-contributions in lower partial waves, then the predictions from "chiral potenti…
One of the main challenges hampering an accurate measurement of the double parton scattering (DPS) cross sections is the difficulty in separating the DPS from the leading twist (LT) contributions. We argue that such a separation can be achieved, and cross section of DPS measured, by exploiting the different centrality dependence of DPS and LT processes in proton-nucleus scattering. We developed a Monte Carlo implementation of the DPS processes which includes realistic nucleon-nucleon (NN) correlations in nuclei, an accurate description of transverse geometry of both hard and soft NN collisions…
Systematic Operator Construction for Non-relativistic Effective Field Theories: Hilbert Series versus Young Tensor
Institute of Theoretical Physics, Chinese Academy of Sciences（中国科学院理论物理研究所）；School of Physical Sciences, University of Chinese Academy of Sciences（中国科学院大学物理科学学院）；School of Fundamental Physics and Mathematical Sciences, Hangzhou Institute for Advanced Study, UCAS（中国科学院大学杭州高等研究院基础科学与数学学院）；International Centre for Theoretical Physics Asia-Pacific, Beijing/Hangzhou（亚太理论物理中心）
Chiral symmetry restoration versus deconfinement in heavy-ion collisions at high baryon density
我们研究了从4到160 A GeV的Parton-Hadron-String Dynamics（PHSD）传输方法中的核-核碰撞中奇异强子的产生，该方法扩展到将手征对称性恢复（CSR）的基本方面纳入强子部门（通过Schwinger机制）中，在PHSD中实现的解除禁闭相变之上。特别是$K^+/π^+$和$(Λ+Σ^0)/π^-$比率在中心的Au+Au碰撞中发现，提供信息的相对重要性的两个过渡。手征对称性恢复的模型是由π-核子$Σ$项驱动的，在夸克标量凝聚$<q {\bar q}>$的计算中，$<q {\bar q}>$作为CSR的序参量，也与有效夸克质量$m_s$和$m_q$近似成比例。此外，核子标量密度$ρ_s$，这也进入了计算的$<q {\bar q}>$，评估的非线性$σ-ω$模型，这是约束的Dirac-Brueckner计算和低能重离子反应。施温格机制（弦衰变）确定了强子介质中奇夸克与轻夸克的产生比例。我们发现，在$\sim$ 80 A GeV以上，重核的反应动力学主要由部分子自由度驱动，因此手征对称性恢复的痕迹很难识别.我们的研究支持了在5 ~ 40 A GeV的重离子碰撞中存在“夸克物质”的猜想，并对30 A GeV左右的$K^+/π^+$比的最大值提供了微观解释，这种最大值只有在反应动力学中加入部分子自由度的跃迁时才出现，而在传统的强子-弦模型中则被抛弃。
Influence of the Nucleon Hard Partons Distribution on J/ΨSuppression in a GMC Framework
在Glauber Monte Carlo框架下，考虑核子中硬部分子的横向空间分布，采用EPS 09阴影参数化方法，分析了d+Au碰撞中$J/ψ$的核修正因子$R_{dAu}$.在考虑核子硬部分子分布的影响后，d+Au碰撞中$R_{dAu}$对$N_{coll}$的依赖性有明显的向上修正，而对$p_{T}$的修正不明显.理论计算结果与PHENIX的实验数据符合得很好。
A simple approach based on the separation of wounded nucleons in an A-A collision in two categories, those suffering single collisions - corona and the rest - core, estimated within a Glauber Monte-Carlo approach, explains the centrality dependence of the light flavor hadrons production in Pb-Pb collisions at $\sqrt{s_{NN}}$=2.76 TeV. The core contribution does not include any dependence of any process on the fireball shape as a function of the impact parameter. Therefore, the ratios of the $p_T$ distributions to the one corresponding to the minimum bias pp collisions at the same energy, each …
We discuss limiting fragmentation within a few currently popular phenomenological models. We show that popular Glauber-inspired models of particle production in heavy ion collisions, such as the two-component model, generally fail to reproduce limiting fragmentation when all energies and system sizes experimentally available are considered. This is due to the energy-dependence of number of participants and number of collisions. We quantify this violation in terms of the model parameters. We also make the same calculation within a Color Glass Condensate scenario and show that the dependence of …
