will take place in Dubna, Russia
at the Veksler and Baldin LABORATORY OF HIGH ENERGY PHYSICS (VBLHEP)
of the Joint Institute for Nuclear Research (JINR)
on October 20-23, 2020
The talk briefly presents history, status, and plans of heavy ion programmes at the CERN SPS. The first measurements started in 1886 and they were concluded twenty years ago by the discovery of a new state matter. The second programme started in 1999 and led to observations of signals of the onset of deconfinement. The currently on-going programme is motivated by a possibility to discover the critical point of strongly interacting matter. An attempt to formulate priorities for future measurements which can be conducted, in particular, at JINR NICA — charm quarks versus the onset of deconfinement and detailed study of the onset of fireball — closes the talk.
RFBR grant 18-02-40056
RFBR grant 18-02-40126
RFBR grant 18-02-40131
RFBR grant 18-02-40092
Tests of Fundamental Symmetries at NICA A feasibility of precision tests of the Standard Model and Beyond in polarization experiments at NICA will be reviewed with an emphasis on internal target experiments with precessing gorizontal polarization of stored protons and deuterons.
RFBR grant 18-02-40085
RFBR grant 18-02-40086
The goal of this project is to develop and deploy experimental measurement techniques for the azimuthal collective flow measurement with the MPD experiment at the NICA collider for different types of hadrons produced in nucleus-nucleus collisions. As a result of the project implementation a numerical modelling of the anisotropic collective flow based on the modern Monte-Carlo event generators of heavy-ion collisions with subsequent simulation of the realistic response of the MPD detector subsystems based on the GEANT platform and reconstruction algorithms build in the MPDROOT will be performed. A set of simulated heavy-ions collisions will be used for deploying of the existing and development of new algorithms for the measurement of the anisotropic collective flow which will utilize different combinations of the MPD detector subsystems.
RFBR grant 18-02-40044
Aim of the project (No 18-02-40044) is to study the collective effects and dynamics of quark-hadron phase transitions using femtoscopic correlations of hadrons and factorial moments of particle multiplicity utilizing the Multi-Purpose Detector (MPD) experiment at NICA. The correlation femtoscopy allows one to measure the space-time characteristics of particle production processes due to the effects of quantum statistics and final state in reactions. We report on the study of the simulated Au+Au and Bi+Bi collisions using UrQMD and vHLLE at NICA energies.
Data analysis was performed using the software packages for femtoscopy and factorial moments analyses developed within the current project. The packages are integrated into the MPD software environment (MpdRoot).
The estimated pion and kaon three-dimensional femtoscopic radii were obtained for the vHLLE+UrQMD (hydrodynamics with the cross over and the first-order phase transitions with hadronic rescattering as an afterburner) and for the UrQMD models (hadron gas transport approach). The influence of the two-particle detector effects such as track-splitting and track-merging on the two-particle correlation functions will be presented. Estimated pion femtoscopic radii are compared with the measurements from the STAR experiment. The factorial moments of particle multiplicities is a sensitive tool to look for the evidence of the change in the type of the phase transition. The sensitivity of s called factorial moments of particle multiplicity on the initial conditions and properties of nuclear matter equation of state will be discussed.
RFBR grant 18-02-40046
I will review the current status of the project. I plan to emphasize the recent analysis of the quasi-free scattering of 48 GeV/c 12C ions from hydrogen, where the final and initial state interactions (FSI/ISI) are largely suppressed. The ground-state distribution of single nucleons is studied by detecting two protons at large angles in coincidence with an intact 11B nucleus. The 11B detection is shown to select the transparent part of the reaction and exclude the otherwise large ISI/FSI
contribution that would break the 11B apart. By detecting the residual 10B and 11Be nuclei, we further identified SRC nucleon-nucleon pairs, and establish the separation of the pair wave-function from that of the residual system. All measured reactions are well described by theoretical calculations that do not contain ISI/FSI. Following the completion of the first analysis phase, a paper was prepared for publication. We plan now to continue analyzing the triple coincidence events with a recoil neutron and to study multi-track events. This is plan in parallel to preparation for the next run.
RFBR grant 18-02-40097
RFBR grant 18-02-40065
RFBR grant 18-02-40035
RFBR grant 18-02-40081
RFBR grant 18-02-40084
RFBR grant 18-02-40130
RFBR grant 18-02-40137
RFBR grant 18-02-40121
RFBR grant 18-02-40069
RFBR grant 18-02-40083
RFBR grant 18-02-40079
The electromagnetic calorimeter is the important part of the NICA / MPD detector in terms of solving fundamental problems in studying of the nuclear matter properties. The high-granularity electromagnetic calorimeter (ECal) of the Multi-Purpose Detector (MPD) at heavy-ion NICA collider is optimized to measure the spatial coordinates and energy of photons and electrons. The production of the calorimeter modules was started this year. This report presents the methods and results of testing and calibration of the ECal modules. A technique for measuring assemblies of calorimeter modules on cosmic muons was developed, which allows calibrating a large number of modules in a wide dynamic range during limited time. For the simultaneous calibration of 12 modules for each of 8 types of modules a special stand was designed and manufactured. The periodic measurement to selective quality control and determination of the main physical parameters of modules was proposed to carry out on an electron beam at various energies. For this purposes, an electron beam of S-25P synchrotron of the Lebedev Physics Institute has been approved. A secondary electron channels was commissioned on the bremsstrahlung photon beam and transported to the calibration area. The calibration measurements were started at the beginning of 2020 with electron beam using an assembly of calorimeter modules at energies from 30 to 300 MeV. A higher electron beam energies are under tests. The simulation programs for beam and cosmic tests were developed. The experimental results in comparison with simulated data are presented and discussed. This work was supported by RFBR grants No. 18-02-40079.
RFBR grant 18-02-40045
RFBR grant 18-02-40054
RFBR grant 18-02-40060
RFBR grant 18-02-40041
I will present the recent results of the feasibility study for the strangeness production and strangeness-to-entropy ratio with the MPD detector at NICA. Transverse momentum spectra and rapidity distributions for charged kaons, pions, and Lambda hyperons were reconstructed in central Au+Au interactions at several collision energies. The prospects of the study of the excitation function of the strangeness-to-entropy ratio at NICA energies will be discussed.
RFBR grant 18-02-40038
RFBR grant 18-02-40036
RFBR grant 18-02-40125
Acquiring, storing, processing and analyzing of experimental and simulated data are an integral part of high-energy physics experiments. These tasks are of particular importance in the experiments of the NICA megaproject due to the high interaction rate and particle multiplicity of ion collision events, therefore the task of automating the considered processes for the NICA complex is a very urgent topic. The report is devoted to the development of new information systems as well as a set of convenient information services for collaboration members to automate the storing and processing data and information on the experiments. The Geometry Information System and Online Electronic Logbook, which are on the final stage of the implementation, are presented. In addition, the design of the Condition Database and Event Metadata System, which are scheduled to be completed next year, are described in detail. The developing systems provide storing information required for event processing and physics analysis and organize a transparent, unified access and data management throughout the life cycle of the scientific researches in the NICA megaproject. One of the key aspects, the integration of the information systems into the experiment workflow is also shown.
RFBR grant 18-02-40104
RFBR grant 18-02-40060
RFBR grant 18-02-40060
RFBR grant 18-02-40036
RFBR grant 18-02-40119
RFBR grant 18-02-40061
Production of charmonia states is a powerful probe of hadron structure. At the SPD experiment, it is considered as one of the main tools to probe the proton spin-dependent gluon distributions. The main disadvantage of this method is the theoretical ambiguity of the charmonia production mechanism. The talk will cover the prospects of the study and the validation of charmonia production mechanisms and measurements of polarization observables at SPD.
RFBR grant 18-02-40061
RFBR grant 18-02-40060
RFBR grant 18-02-40102
RFBR grant 18-02-40102
RFBR grant 18-02-40104
RFBR grant 18-02-40046
RFBR grant 18-02-40046
Theoretical model of the reaction $^{12}$C(p,2pN)$^{10}A$ is developed in the plane wave approximation assuming pole mechanism of quasi-elastic knock-out of the nucleon from the short-range correlated (SRC) NN-pair. Spectroscopic factors for two nucleons in a definte spin ($S$) and isospin ($T$) states in the $^{12}$C nucleus are calculated within the translationally-invariant shell model. High momentum part of the internal wave function of the NN-pair is replaced by the realistic wave function of the deuteron $(ST=10)$ or singlet ($^1S_0$) deuteron $(ST=10)$.Numerical calculations for distributions over momentum of the nucleon spectator and c.m. momentum of the NN-pair are performed at proton beam energy 4 GeV.
RFBR grant 18-02-40044
RFBR grant 18-02-40051
RFBR grant 18-02-40125
The report is dedicated to the Geometry Information System based on the Geometry Database, which is developed for the experiments of the NICA project. The feature of the NICA experiments is a similar approach to storing detector geometries and methods to use them, which employ ROOT or ASCII (.geo) formats and common interfaces of the FairRoot software developed by the FAIR collaboration. The main purpose of the system is to provide a centralized storage of detector geometries, which are actively used in detector simulation and data processing, convenient tools for managing geometry modules, and ensure versioning of the setup assemblies as a combination of the modules and additional support files. The unification of the Geometry Database allows to minimize the cost of creating and maintaining a geometry database for each experiment. The report shows the structure of the Geometry Database, access roles and its implementation features. An important part of any information system – interfaces, such as Application Programming Interface (API) and user-friendly Web interface, will be also presented.
RFBR grant 18-02-40061
Projected high volume and rate of data that will be collected and produced by SPD experiment requires a special strategy for the organization of data processing (computing). Experience and technology level reached during the organization computing for LHC experiments should be, at least, taken into account for new HEP experiments which will produce a significant amount of data.
In this talk, we are going to present the computing infrastructure for SPD experiment and describe an organization of a set of services that will help with the automation of data processing by managing data and calculation in a distributed environment.
RFBR grant: 18-02-40101
Computing and storage resources are essential for effective Monte-Carlo generation. In JINR there are several different resources. Tier1 and Tier2 clusters, Govorun supercomputer, JINR Cloud, and NICA cluster as computing resources. EOS disk storage and dCache tape storage. To use all these resources individually users have to be aware of many details and differences between resources and keep track of load on all of them. DIRAC Interware was adopted, configured, and expanded to fulfill requirements to allow massive simultaneous Monte-Carlo generation for MPD. For a year the joint infrastructure was used via DIRAC to run successfully 380000 jobs with an average duration of 5 hours each. The use of DIRAC allowed unified data access, performance estimation, and accounting across all resources.
RFBR grant 18-02-40044
RFBRgrant 18-02-40086
RFBR grant 18-02-40081
RFBR grant 18-02-40041
RFBRgrant 18-02-40045
We present calculations of direct photon yield in Au-Au collisions at center of mass energies between 5 and 11 GeV which are anticipated at future NICA and FAIR facilities. The calculations are based on UrQMD package with hybrid approach for description of the evolution of the collision and parameterizations of thermal radiation from electromagnetic interactions in hadron gas and quark-gluon plasma. The feasibility studies of direct photon measurements in MPD with ECal will be discussed.
RFBR grant 18-02-40101
RFBR grant 18-02-40102
RFBR grant 18-02-40051
RFBR grant 18-02-40113
RFBR grant 18-02-40047
BM@N experiment at Nuclotron is currently being upgraded in order to study the high-density nuclear equation-of-state in collisions between gold nuclei at beam energies 2– 4.5 AGeV. The measurement of high-multiplicity events at interaction rates up to 5 MHz requires the installation of four new tracking stations equipped with double-sided micro-strip silicon sensors, which have been developed for the CBM experiment at FAIR. Silicon Tracking System will comprise ~600 k channels with fast data driven readout electronics. Data acquisition system for the Silicon Tracking System of BM@N experiment should approve a new principle of data acquisition in a data driven mode, which will be used later in CBM. However, it should also operate with a trigger signal, provided by the trigger system of BM@N experiment. For this task a readout system, which is capable to work both in trigger and self-trigger modes and is adopted for the requirements of BM@N experiment, is developing in a close collaboration with CBM group.
RFBR grant 18-02-40119
RFBR grant 18-02-40075
RFBR grant 18-02-40093
RFBR grant 18-02-40061
RFBR grant 18-02-40119
The MPD detector will be equipped with a high-resolution, ultra-light Inner Tracking System (MPD-ITS) consisting of five concentric layers of Monolithic Active Pixel Sensors (MAPS), divided into a 3-layers Inner Barrel and a 2-layers Outer Barrel. The Inner Barrel will be based on the next generation of MAPS currently under development by the ITS3 project of the ALICE collaboration at CERN, while the Outer Barrel will be based on the same ALPIDE MAPS used during the upgrade of the ALICE-ITS for its own Outer Barrel. The different stages of the MPD-ITS construction will be carried out as part of a collaboration between institutions from Russia (JINR, SPbSU, MSU) and China (CCNU, IMPh, USTC), with assembly sites in both countries. The presentation will provide an overview of the detector's assembly process with a particular emphasis on the assembly of the Hybrid Integrated Circuits (the basic modules of the tracking system) and its current status towards the production readiness.
RFBR grant 18-02-40119
RFBR grant 18-02-40047
The Silicon Tracking System (STS) of BM@N experiment will be based on modules with double-sided microstrip silicon sensors, which have been developed for the CBM experiment at FAIR. STS will comprise ~600k channels with a fast data-driven readout electronics based on STSXYTER ASIC. ASIC was tested and characterized. A dedicated front-end board with 8 ASICs adopted for the integrational requirements of BM@N experiment was developed.
RFBR grant 18-02-40047
The Silicon Tracking System (STS) of BM@N experiment will be based on modules with double-sided microstrip silicon sensors, which have been developed for the CBM experiment at FAIR. Each module consists of a double-sided sensor, two front-end boards with 8 ASICs each and a set of low-mass aluminum microcables. During the module assembly microcables are Tab-bonded to the sensor and readout ASICs. Each module has 1024 channels on both sides. For the quality assurance of the bonding parameters a dedicated procedure based on the noise per channel measurements in a Pogo-Pin test circuit was developed.
RFBR grants 18-02-40047 and 18-02-40113
BM@N experiment at Nuclotron in Dubna is currently being upgraded for a study of dense nuclear matter in heavy ion collisions. One of the major upgrades is a new hybrid tracking system consisting of four large-aperture Silicon Tracking Stations (STS) and seven GEM planes. STS is based on modules equipped with double-sided microstrip silicon sensors developed for the FAIR/CBM experiment. The BM@N STS consist of 292 silicon modules. Original technological workflow and first results of the module assembly for the BM@N STS developed by the JINR working group at VB LHEP are presented.
RFBR grant 18-02-40113
RFBR grant 18-02-40113
RFBR grant 18-02-40075
RFBR grant 18-02-40061
The Range System (RS) is one of the essential detectors of the SPD installation, which is currently under preparation for the second interaction point of NICA collider. RS provides identification of muons and can also be used as a coarse hadronic calorimeter. The SPD Range System design and geometry modeling are presented as well as main results of the RS prototype tests.
RFBR grant 18-02-40061, 18-02-40079
RFBR grant 18-02-40061
MiniSPD is an installation for cosmic muon tests of all types of the detectors that will be used in the SPD setup. It includes the scintillator-based trigger system, straw, silicon and GEM trackers, modules of the electromagnetic calorimeter and the lead filter to remove the soft component of cosmic rays. It will be used for the measurement of such important parameters as spatial and time resolution, efficiency, drift characteristics, amplification etc. Data acquisition, slow control and online monitoring systems could also be tested there.
RFBR grant 18-02-40075
RFBR grant 18-02-40075
RFBR grant 18-02-40075
The energetic and time response of electromagnetic calorimeter prototypes and the features of technological solutions used in the development of the investigated calorimetric modules are presented. The energy and time resolution of the prototype was measured in cosmic rays. The dependence of the calorimeter response on temperature and the possibility of signal stabilization due to thermal compensation of the operating voltage of the photodiodes are shown.
Status and updates News about LPI Moscow setup for pixel modules testing.
RFBR grant 18-02-40056
RFBR grant 18-02-40085
A brief review of theoretical studies of polarization in collisions of relativistic heavy ions with an emphasis on the NICA energies is given. The current state of research within the framework of the RFBR grant No. 18-02-40085 is described in the context of the modern state-of-the-art.
RFBR grant 18-02-40126
The influence of the rotation on the confinement/deconfinement phase transition in SU(3)-gluodynamics was investigated using the Monte-Carlo lattice simulations. The calculations have been performed in rotating reference frame, where the rotation is introduced using an external gravitational field. To study the confinement/deconfinement transition the Polyakov loop and its susceptibility have been computed for various values of the temperature and angular velocity. The obtained results show that the critical temperature of the confinement/deconfinement phase transition in SU(3)-gluodynamics increases with a growth in the angular velocity. It is shown that this effect does not depend on the lattice size and boundary conditions used.
Within the three-flavor PNJL and EPNJL chiral quark models we have obtained pseudoscalar meson properties in quark matter at finite temperature $T$ and baryochemical potential $\mu_B$.
We compare the meson pole (Breit-Wigner) approximation with the Beth-Uhlenbeck (BU) approach that takes into account the continuum of quark-antiquark
scattering states when determining the partial densities of pions and kaons.
We evaluate the kaon-to-pion ratios along the (pseudo-)critical line in the $T-\mu_B$ plane as a proxy for the chemical freezeout line, whereby the variable
$x=T/\mu_B$ is introduced that corresponds to the conserved entropy per baryon as initial condition for the heavy-ion collision experiments.
We present a comparison with the experimental pattern of kaon-to-pion ratios within the BU approach and using $x$-dependent pion and strange quark potentials.
A sharp "horn" effect in the energy dependence $K^+/\pi^+$ ratio is explained by the enhanced pion production at energies above $\sqrt{s_{NN}}=8$ GeV, when
the system enters the regime of meson dominance.
This effect is in line with the enhancement of low-momentum pion spectra that is discussed as a precursor of the pion Bose condensation and entails the
occurrence of a nonequilibrium pion chemical potential of the order of the pion mass.
We elucidate that the horn effect is not related to the existence of a critical endpoint in the QCD phase diagram. in the QCD phase diagram.
The most interesting region of the QCD phase diagram lies close to the critical temperature at finite quark density. When the temperature is approaching the critical one from above the strong fluctuation regime sets in. We reveal and analyze the unusual behavior of the transport coefficients under the impact of fluctuations. These include the bulk viscosity, speed and attenuation of the sound, soft photon emissivity and some others.
We discuss influence of anisotropy caused by external magnetic field on holographic description of hot dense anisotropic quark-gluon plasma. For this purpose we generalize previous anisotropic solution obtained in AdS5/CFT4 (JHEP 05, 206 (2018), PLB 792, 470 (2019)).
We present a 5-dimensional anisotropic holographic model for light and heavy quarks supported by Einstein-dilaton-two-Maxwell action. This model generalizes isotropic (arXiv:1506.05930, 1703.09184) and anisotropic (arXiv:1802.05652, 1808.05596 ) holographic backgrounds that are characterized by a Van der Waals-like phase transition between small and large black holes.
Hot and dense hadronic matter created in the early stages of relativistic heavy-ion collisions has strong spatial anisotropy. The rapid expansion of matter along the beam-axis in the first moments after the collision leads to a strong drop in the ratio of longitudinal and transverse pressures. One of the hydrodynamic descriptions of such a system is the anisotropic approach, in which the anisotropy parameter is explicitly introduced for the one-particle distribution function.
The question of how to generate shock waves in a quark-gluon plasma is still open, but it is clear that they exist in such a medium, that is very well described by hydrodynamic equations. Shock waves are closely related to the jet quenching effect and hadronization; therefore, it is especially interesting to study them in the context of anisotropic system. Registration of shock waves in matter created in relativistic collisions of heavy nuclei directly depends on the degree of their stability. The stability of shock waves has not yet been studied for anisotropic hydrodynamics.
The purpose of this report is to highlight the problem of shock wave stability in anisotropic relativistic hydrodynamics. The influence of small perturbations on the behavior of the discontinuity surface will be considered, and the dependence of this behavior on the anisotropy parameter will also be studied.