Monte Carlo event generators for NICA/MPD and CBM

Monte Carlo event generators for NICA/MPD and CBM experiments A. S. Galoyan and V. V. Uzhinsky (JINR, Dubna, 2 July 2015) Project NICA/MPD is dedicated to study of hot and dense baryonic matter Physics tasks (to be studied for different ions (from p to Au) by scanning in b and energy (in the range Ecms= 4 — 11 Ge. V/c) : event-by-event fluctuation in hadron productions (multiplicity, Pt) femtoscopic correlation directed and elliptic flows for various hadrons multi-strange hyperon production: yield and spectra (the probes of nuclear media phases) photon and electron probes charge asymmetry

FAIR — An International Facility for Antiproton and Ion Research CBM – the Compressed Baryonic Matter Experiment The goal of CBM research program is the investigation of highly compressed nuclear matter in nucleus-nucleus collisions at E = 10 – 40 Ge. V/n Study the properties of super-dense nuclear matter. Search for in-medium modification of hadrons. Search for the transition from dense hadronic matter to quark-gluon matter, and for the critical endpoint in the phase diagram of strongly interacting matter In particular, the program is focused to study of: short-lived light vector mesons which decay into e-/e+ pairs. strange particles, in particular baryons containing more than one strange quark, so called multistrange hyperons (Λ, Ξ, Ω); charmed mesons (D, J/Ψ); collective flow of all observed particles. event-by-event fluctuations.

Monte Carlo event generators String models Ultra-relativistic Quantum Molecular Dynamics – Ur. QMD Quark-Gluon String Model — QGSM Cascade models Intra-nuclear cascade models Gi. BUU (Giessen), A Relativistic Transport — ART Parton cascades A Multi-Phase Transport — AMPT Hadron String Dynamics — HSD Fluid dynamics One-fluid hydrodynamics Three-fluid model Viscous fluid dynamics Proton rapidity and inverse slope distributions compared to simple thermal source predictions for Au+Au collisions at three beam energies. Description of protons, neutrons and fragment properties is a problem in all MC generators! At fixed beam’s energies events are subdivided on centrality classes. At low and intermediate energies LCP are used for this aim. At high energies? + Geant 3 or Geant 4 simulation toolkit

Monte Carlo event generators are quite detailed, thus basic representations are used at the begining 3. Neutron production in h. A and AA interactions 1. Glauber calculations for beam energy scan (BES) B. Alver, M. Baker, C. Loizides, P. Steinberg ar. Xiv: 0805. 4411. [nucl-exp]. 2005 “ The FOBOS Glauber Monte Carlo” PHENIX, STAR, FOBOS, ALICE, CMSParameters of interactions: 1. Impact parameter (fm) 2. Number of interacting nucleons 3. Number of binary collisions 4. Eccentricity of interaction region 5. Masses of residual nuclei 42. Coupling of the calculations with observabilities

The FOBOS Glauber Monte Carlo Code B. Alver, M. Baker, C. Loizides, P. Steinberg ar. Xiv: 0805. 4411. [nucl-exp]. 2005 A, B – mass number of nuclei , b – impact parameter In the code parameters ω, R and a are given for nuclei p, d, O, Si, S, Ca, Ni, Cu, W, Au, Pb, U V We use nuclear parameters from L. C. Chamon et al. , Phys. Rev. , C 66, 014610 (2002).

6 NN elastic scattering amplitude P. Brogueira and J. Dias de Deus, Eur. Phys. J. 37 (2010) 075006). Real part of elastic p-p amplitude. Derivative dispersion relations J. B. Bronzan, G. L. Kane, U. P. Sukhatme, Phys. Lett. 49 B (1974) 227; M. M. Block, R. N. Cahn, Rev. Mod. Phys. 57 (1985) 563 Standard representation of elastic h. N scattering B is the slope parameter of h. N differential elastic cross section D. W. L. Sprung and J. Martorell, J. Phys. A 30 (1997) 6525; A 31 (1998) 8973.

Fit of exp. data on elastic PP scatterings 68 sets of exp data on PP-scatterings were used

Approximation of R pp (R pbarp ) and d pp (d pbarp ) 8“ Structure of antiproton-proton elastic scattering amplitude” A. Galoyan, V. Uzhinsky, JETP Letters, v. 94, No 7 (2011)

Results of Totem experiment on pp-scatterings at 7 Te. V EPL, 95 (2011) 41001, EPL 96 (2011) 21002 R=1. 07 fm, d=0. 375 fm V. Uzhinsky, A. Galoyan, Nov 2011. e-Print: ar. Xiv: 1111. 4984 «Description of the Totem experimental data on elastic pp-scattering at sqrt(s)=7 Te. V in the framework of unified systematic of elastic scattering data. “

Screening effect at NICA Calculation results for NICA/MPD 10. V. Uzhinsky, A. Galoyan «Gribov’s inelastic screening in high energy nucleus-nucleus interaction». Phys. Lett. B 721 (2013)

Modified Glauber Monte Carlo programm 11 Geometrical property dependences on collision centrality at NICA and RHIC At such event dividing, Npart, Ncoll distributions don’t overlape at С < 80 % for NICA and RHIC. Centrality: 0 -5, 5 -10, 10 -20, 20 -40, 40 -60, 60 -80, 80 -100 %

Modified Glauber Monte Carlo program 12 Dependence of mean geometrical properties on collision centrality at NICA and RHIC. Centrality: 0 -5, 5 -10, 10 -20, 20 -40, 40 -60, 60 -80, 80 -100 % At such binning, , don’t overlape at С < 80 % for NICA and RHIC. Anisotropy distributions overlape strongly at all centralities. Monte Carlo program for NICA/MPD and CBM experiments. A. S. Galoyan, V. V. Uzhinsky Phys. Part. Nucl. Lett. 12 (2015) 1,

13 Geometrical property dependences on collision centrality for Pb+Pb (2760 Ge. V), p+Pb (5020 Ge. V) ─ ALICE collab. Modified Glauber Monte Carlo program Particle Production and Binary Scaling in p-Pb Collisions with ALICE Andreas Morsch on behalf of the ALICE Collaboration CERN LHC Seminar November 12, 2013 CERN-PH-EP-2014 -281 17 November 2014 Centrality dependence of particle production in p–Pb collisions at √ s. NN= 5. 02 Te. V ALICE Collaboration

14 The geometrical properties cannot be measured directly. Thus, they must be connected with observailities. CERN-PH-EP-2012 -368 18 Dec 2012 Centrality determination of Pb–Pb collisions at Ecms. NN= 2. 76 Te. V with ALICE Collaboration

15 Neutron production in nucleus-nucleus interactions FTF (Geant 4) model calculations Physics of Atomic Nuclei, 2006, Vol. 69, No. 9, pp. 1496– 1509 Neutron Emission in Interactions of H-1, H-2, He-4, and C-12 Nuclei with Lead Nuclei at 1– 2 Ge. V per Nucleon V. I. Yurevich, R. M. Yakovlev, V. G. Lyapin (JINR, RI St. Peterburg) Scaling and Asymptotical Properties of Slow Neutron Inclusive Cross Sections in High Energy Hadron- Nucleus Interactions} A. Galoyan, A. Ribon, V. Uzhinsky Yu. D. Bayukov et al. , ITEP preprint No 172 (1983).

16 Summary 1. Modified Glauber Monte Carlo code is created for future experiments ● Well grounded parameters “R” and “c” of Saxon-Wood’s nuclei densities are used for all stable nucleus; ● Physical valid amplitude of elastic nucleon-nucleon scattering is applied; ● Calculation of anisotropy of the interaction region “Essentricity” is included in the program; ● Gribov’s inelastic screenings in nucleus-nucleus interactions are implemented in the code; 2. It is shown that geometrical properties of nucleus-nucleus interactions at RHIC and NICA/FAIR energies are quite close to each other. 3. Predictions of various Monte Carlo models for meson production in AA interactions are varied in the range ± 50 % for Ecms=5 – 10 Ge. V. 4. A big disagreement between the model predictions is observed for spectator neutron productions. 5. Reasonable descriptions of neutrons spectra are reached in the FTF model of Geant 4 toolkit. Scaling effect of slow neutron inclusive cross sections is observed at analysis of exp. data on nucleon-nucleus interactions. We believe that high energy nucleus-nucleus interactions can be useful for nuclear physics. Decay of high excited nuclei can be studied.

The geometrical properties cannot be measured directly. Thus, they must be connected with obserbailities. Particle Production and Binary Scaling in p-Pb Collisions with ALICE Andreas Morsch on behalf of the ALICE Collaboration CERN LHC Seminar November 12,

Properties of particles produced nucleus-nucleus interactions at 5 Ge. V/Nucleon

The geometrical properties cannot be measured directly. Thus, they must be connected with obserbailities. Nuclear Instruments and Methods in Physics Research A 470 (2001) 488– 499 The RHIC zero degree calorimeters C. Adler, A. Denisov, E. Garcia, M. Murray, H. Stroebele, S. White

Позволяет моделировать: неупругие и упругие Pbar+P , Pbar+A взаимодействия ( PANDA ), A+A взаимодействия для MPD/NICA Ультрарелятивистская квантовая молекулярная динамическая модель – Ur. QMD +

Calculation results for NICA/MPD 11 Eccentricity estimations