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Young scientists research


MESONS AND DIQUARKS IN THE NAMBU-JONA-LASINIO MODEL: CHIRAL SYMMETRY AND SUPERFLUIDITY

D. Zablocki, D. Blaschke and Yu. Kalinovsky


The relationship between mesonic correlations and quantum condensates in the quark matter phase diagram of QCD with two colors and two flavors of light quarks is explored within a quantum field theoretical approach of the Nambu-Jona-Lasinio(NJL) type. We point out that the two-color QCD is nontrivial enough to contain the essential ingredients for the QCD critical endpoint and a new phase called quarkonic matter.

THERMODYNAMICS OF THE NAMBU-JONA-LASINIO MODEL AND SCALAR ? MESON

A. Friesen, Yu. Kalinovsky, V. Savushkin and V. Toneev


The thermodynamics of a quark/meson plasma is studied within the Nambu-Jona-Lasinio(NJL) models at finite temperature and chemical potential. We review the results that have been obtained in the mean field approximation. The decay rate for the process is calculated as a function of temperature and baryon number density.

ELECTRON IDENTIFICATION IN THE CBM EXPERIMENT AT FAIR

S. Lebedev, C. Hohne and G. Ososkov for the CBM collaboration


The Compressed Baryonic Matter (CBM) experiment at the future FAIR facility in Darmstadt will measure dileptons emitted from the hot and dense phase in heavy-ion collisions. In this contribution we present procedures developed for the electron identification in CBM. A RICH ring recognition algorithm based on the Hough transform has been implemented. An ellipse fitting algorithm has been elaborated in view of the fact that most of the CBM RICH rings have elliptic shapes. Moreover, it helps to improve ring-track matching and electron identification procedures. An Artificial Neural Network can be used in order to suppress fake rings. The electron identification in RICH is substantially improved by the use of TRD information for which 3 different algorithms are implemented. Results of primary electron identification are presented. All developed algorithms were tested on large statistics of simulated events and are included into the CBM software framework.

FAST PARALLELIZED TRACKING ALGORITHM FOR THE MUON DETECTOR OF THE CBM EXPERIMENT AT FAIR

A. Lebedev, C. Hohne, I.Kisel and G. Ososkov for the CBM collaboration


Particle trajectory recognition is an important and challenging task in the Compressed Baryonic Matter (CBM) experiment at the future FAIR accelerator at Darmstadt. The tracking algorithms have to process terabytes of input data produced in particle collisions. Therefore, the speed of the tracking software is extremely important for data analysis. In this contribution, a fast parallel track reconstruction algorithm which uses available features of modern processors is presented. These features comprise a SIMD instruction set and multithreading. The first allows to pack several data items into one register and to operate on all of them in parallel thus achieving more operations per cycle. The second feature enables the routines to exploit all available CPU cores and hardware threads. This parallelized version of the tracking algorithm has been compared to the initial serial scalar version which uses a similar approach for tracking. A speed up factor of 140 was achieved (from 630 msec/event to 4.5 msec/event) for an Intel ® Core 2 Duo processor at 2.26 GHz.

IDENTIFICATION WITH THE TRANSITION RADIATION DETECTOR IN THE CBM EXPERIMENT

E.P. Akishina, T.P. Akishina, V.V. Ivanov and O.Yu. Derenovskaya


The problem of e/p identification using a n-layered transition radiation detector (TRD) in the CBM experiment is considered. To this aim, we elaborated algorithms and implemented various approaches. We discuss the characteristic properties of the energy losses by the electrons and pions in the TRD layers and the special features of the artificial neural networks (ANN) and statistical methods enabling the solution of the problem under consideration. A comparative analysis is performed on the power of the statistical criteria and ANN.

ON ELECTRON AND PION IDENTIFICATION USING A MULTILAYER PERCEPTRON IN THE TRD OF THE CBM EXPERIMENT

T.P. Akishina, V.V. Ivanov and O.Yu. Derenovskaya


The problem of pion/electron identification based on their energy losses in the transition radiation detector (TRD) is considered in the frame of the CBM experiment. For particle identification, an artificial neural network (ANN) was used. This is a multilayer perceptron built in JETNET and ROOT packages. It is demonstrated that, in order to get correct and comparable results, it is important to define the network structure correctly. In order to achieve an acceptable level of pions suppression, the energy losses need to be transformed to more "effective" variables.

DISTRIBUTED TRAINING AND TESTING GRID-INFRASTRUCTURE FOR JINR AND ITS MEMBER STATES ACTIVITIES

S.D. Belov, V.V. Korenkov and N.A. Kutovskiy


Grid-technologies have already became standard tools used by scientists in different fields and first of all in high-energy physics. The associated steep learning curve may be alleviated within a dedicated education and training process. To this purpose, a distributed training and testing grid-infrastructure has been set up with core services at LIT JINR and integrating resources of several organizations from JINR member states. It is used for educating and giving practical tutorials to students of UC JINR, JINR and its member states colleagues as well as for performing obligations in different Grid related activities of local and international projects.

METHODS FOR PARAMETER ESTIMATIONS OF THE CHERENKOV RADIATION RINGS IN THE RICH DETECTOR FOR CBM EXPERIMENT

A. Ayriyan, N. Chernov, V. Ivanov, S. Lebedev and G. Ososkov


Since the elliptic model of Cherenkov radiation rings in the RICH detector of the CBM experiment was recently accepted in addition to the previous circular one, an ellipse fitting algorithm based on the Kepler equation of the ellipse with the following MINUIT minimization has been elaborated (Minuit Fitter). To avoid the time-consuming MINUIT application we proposed a new direct ellipse fitting algorithm based on the Taubin method. We describe and perform a comparative study of the two algorithms. It is important to stress that the Taubin method is non-iterative. As a consequence, it is much faster than the Minuit Fitter and, moreover, it is statistically more accurate. After detailed testing on a large statistics of simulated data, the corresponding software implementing the Taubin-based algorithm was also included in the CBM Framework and used as default method.

FTS (FILE TRANSFER SERVICE) MONITORING FOR WORLDWIDE LHC COMPUTING GRID (WLCG) PROJECT.

A.Uzhinsky


In addition to fulfilling their tasks, the WEB-services have to provide nowadays full information about their functioning and have to supply the user with a friendly interface for the management of their settings and state. FTS is one of the most important data transfer services in gLite. The gLite is a middleware produced by the EGEE (Enabling Grids for E-sciencE project). FTS is responsible for distribution of data from LHC according to the scheme [1] produced by WLCG (Worldwide LHC Computing Grid project). FTS development team improves FTS service in order to follow the above described tendencies. Works in this direction are carried out by JINR and SINP MSU researchers in the collaboration with CERN. The structure, functionality and the most interesting features of the FTS monitoring system are presented. The general strategy of the monitoring tools development is considered. System reports, interfaces, ability and alarm mechanism are discussed.

[1] V.V. Korenkov, A.V. Uzhinskiy, Architecture of the Data Transfer Service in Grid ("A?oeoaeoo?a na?aena ia?aaa?e aaiiuo a a?ea"), Open System, 2008, N2.

MONITORING AND ACCOUNTING OF THE RUSSIAN DATA INTENSIVE GRID (RDIG)

S. Belov, V. Korenkov


Different monitoring systems are now extensively used to keep an eye on real time state of each service of the distributed grid-infrastructures and jobs running on the Grid. Tracking current services' state as well as the history of state changes allows rapid error fixing, planning future massive productions, revealing regularities of Grid operation and many other things. Along with monitoring, the accounting is an area which shows how the Grid is utilized by virtual organizations and single users. Here we describe our longstanding experience in successful development and design of Grid monitoring and accounting systems for Russian Data Intensive Grid (within the EGEE project). The underlying feature of the developments was the fulfillment of the real needs of the virtual organizations and resource managers and administrators, as well as providing interoperable and portable solutions for several grid projects.

USER-INTERFACE AND VISUALIZATION SERVICE DEVELOPMENT FOR VIRTUAL ORGANIZATION SUPPORT IN HIGH ENERGY PHYSICS.

S.Mitsyn


The problem of visualization of grid-infrastructure monitoring data as a geographically distributed high performance computing system involving the use of geographic maps and 3D models of Earth is considered. The implementation of monitoring visualization for the Dashboard project - the primary application of which is the grid-infrastructure monitoring support for the four large LHC experiments - based on the Google Earth as its user interface core, is considered. Problems of such visualization which had to be faced during implementation phase are outlined. Also the solution of job execution monitoring for Hone virtual organization of H1 experiment build on top of MonALISA, which is in the running state for more than a year, is being considered.

LCG MONTE-CARLO EVENTS DATA BASE - LCG MCDB

S. Belov, L. Doudko, A. Sherstnev


The way of making a Monte Carlo simulation chain fully automated is presented. The main motivation behind the LCG MCDB project is to make sophisticated MC event samples and their structured descriptions available for various groups of physicists working on LHC. All the data from MCDB is accessible for end-users in several convenient ways from Grid, on the Web and via application program interface. Developed within the collaboration of LCG MCDB and CEDAR teams and several MC generator authors, HepML (High Energy Markup Language) is aimed be a unified XML description of event samples simulated by Matrix Element (ME) generators. The other main purpose of HepML is to keep MC generation parameters for further MC generators tuning. Using MCDB and HepML together gives the possibility of the automation of such significant part of the MC simulation chain as the correct transfer physics events from Matrix Element generators to Shower generators and then to detector simulation.

DILEPTON PAIR SIMULATION FOR NICA/MPD

D. Emelyanov


The production of di-lepton pairs e+e- and µ+µ-- in nuclear collisions is investigated at NICA energy Vs = 9GeV. Vector mesons decaying into di-lepton pairs are generated with the package "Pluto" and embedded into central Au+Au collisions. Calculated spectra of effective masses of di-lepton pairs are filtered with the geometrical acceptance of the NICA/MPD detector.


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