We introduce the Modular Algorithm for Relativistic Treatment of heavy IoN Interactions (MARTINI), a comprehensive event generator for the hard and penetrating probes in high energy nucleus-nucleus collisions. Its main components are a time evolution model for the soft background, PYTHIA 8.1 and the McGill-AMY parton evolution scheme including radiative as well as elastic processes. This allows us to generate full event configurations in the high p_T region that take into account thermal QCD and QED effects as well as effects of the evolving medium. We present results for the neutral pion nuclear modification factor in Au+Au collisions at RHIC as a function of p_T for different centralities, and also as a function of the angle with respect to the reaction plane for non-central collisions. Furthermore, we study the production of high transverse momentum photons incorporating a complete set of photon-production channels.
Implementation of the Martini-Ericson-Chanfray-Marteau RPA-based neutrino and antineutrino cross-section model in the GENIE neutrino event generator
Sorbonne Université, CNRS/IN2P3, Laboratoire de Physique Nucléaire et de Hautes Energies (LPNHE)(索邦大学);IPSA-DRII;CERN, European Organization for Nuclear Research(欧洲核子研究中心)
Charm quark evolution in the early stages of heavy-ion collisions
Vanderbilt University(范德堡大学);Indian Institute of Technology (Indian School of Mines)(印度理工学院(印度矿业学院));Brookhaven National Laboratory(布鲁克海文国家实验室);McGill University(麦吉尔大学)
We present an update of the event generator based on the three-fluid dynamics (3FD), complemented by Ultra-relativistic Quantum Molecular Dynamics (UrQMD) for the late stage of the nuclear collision~-- the three-fluid Hydrodynamics-based Event Simulator Extended by UrQMD final State interactions (THESEUS). Two modifications are introduced. The THESEUS table of hadronic resonances is made consistent with that of the underlying 3FD model. The main modification is that the generator is extended to simulate the light-nuclei production in relativistic heavy-ion collisions, on the equal basis with h…
In neutrino event generators, for models for neutrino and electron scattering only inclusive cross sections are implemented. When these models are used to describe a semi-inclusive cross section, the event generator attaches the hadron variables based on some assumptions. In this work we compare the nucleon kinematics given by the method used in the GENIE event generator, e.g. in the implementation of the SuSAv2 model, to a fully unfactorized calculation using the relativistic distorted wave impulse approximation (RDWIA). We focus on kinematics relevant to the $e4ν$ analysis and show that obse…
In this work we obtain the analytical expressions for the boundaries of the charged current quasi-elastic double differential cross section in terms of dimensionless energy and momentum transfers, for the Relativistic Fermi Gas (RFG) and the Super-Scaling approach with relativistic effective mass (SuSAM*) models, within the scaling formalism. In addition, we show that this double differential cross section in the scaling formalism has very good properties to be implemented in the Monte Carlo (MC) neutrino event generators, particularly because its peak is almost flat with the (anti)neutrino en…
Using event-by-event fluctuations, we study the diffusion parameters of net-charge, net-pion, net-kaon, and net-proton in the heavy-ion jet interaction generator (HIJING), and ultra-relativistic quantum molecular dynamics (UrQMD) models at different collision energies \sqsn available at BNL Relativistic Heavy Ion Collider (RHIC). The diffusion parameter ($σ$) of net-charge and identified particles are estimated in rapidity space at various \sqsn. It is observed that, the $σ$ values are independent of collision energies but emphasises the particle-species dependence of diffusion coefficient in …
GenEx: A simple generator structure for exclusive processes in high energy collisions
本文提出了一个简单的C++类结构,用于构造一个能在相对论相空间中产生未加权事件的蒙特卡罗事件发生器。该生成器是自适应提供的矩阵元素和验收切割。该计划是专门为排他性的过程,并包括,作为这样的应用程序的一个例子,在高能量质子-质子碰撞的介子对$pp \rightarrow p M^+M^- p $排他性生产模型的实施。
We study the hadron production in $p+p$, $p+n$ and $n+n$ reactions within the microscopic Parton-Hadron-Dynamics (PHSD) transport approach in comparison to PYTHIA 8.2. We discuss the details of the "PHSD tune" of the Lund string model (realized by event generators FRITIOF and PYTHIA) in the vacuum (as in $N+N$ collisions) as well as its in-medium modifications relevant for heavy-ion collisions where a hot and dense matter is produced. We compare the results of PHSD and PYTHIA 8.2 (default version) for the excitation function of hadron multiplicities as well as differential rapidity $y$, transv…
A calculation of the transport coefficients of hot and dense hadronic matter based on the event generator URASiMA
利用事件发生器URASiMA(Ultra-Relativistic AA Collision Simulator based on Multiple Scattering Algorithm),在周期边界条件下计算了稠密热强子物质的物理量和输运系数。作为输运系数的最简单的例子,我们研究了稠密热强子物质的重子扩散常数的温度依赖性和化学势依赖性。
Baryon Diffusion Constant in Hot and Dense Hadronic Matter Based on an Event Generator Urasima
在URASiMA(Ultra-Relativistic AA Collision Simulator based on Multiple Scattering Algorithm)中,通过施加周期性边界条件,生成了具有固定温度和化学势的平衡态统计系综。利用所产生的系综,我们研究了稠密热强子物质的核子扩散常数的温度依赖性和化学势依赖性。
The strangeness enhancement signature of QGP formation at LHC energies is carefully tackled in the present study. Based on HRG, the particle ratios of mainly strange and multi-strange particles are studied at energies from lower $\sqrt{s}\sim $ 0.001 up to 13 TeV. The strangeness enhancement clearly appeared at more higher energies, and the ratios are confronted to the available experimental data. The particle ratios are also studied using the Cosmic Ray Monte Carlo (CRMC) interface model with its two different event generators namely; EPOS $1.99$ and EPOSlhc which show a good agreement with t…