S. A. Bass

Publication List Details

Period

1995 - 2008

Number

97

Co-Authors

Systematic Comparison of Jet Energy-Loss Schemes in a 3D hydrodynamic medium (2008)

Bass, S. A., Gale, C., Majumder, A., Nonaka, C., Renk, T., ...

We utilize a 3D hydrodynamic model to provide the medium evolution for a systematic comparison of jet energy-loss calculations in the BDMPS/ASW, HT and AMY approaches. We find that the parameters of...

Transverse Velocity Dependence of the Proton-Antiproton Ratio as a Signature of the QCD Critical Endpoint (2008)

Asakawa, M., Bass, S. A., Müller, B., Nonaka, C.

The presence of a critical point in the QCD phase diagram can deform the trajectories describing the evolution of the expanding fireball in the $\mu_B-T$ phase diagram. If the average emission time...

Jet modification in three dimensional fluid dynamics at next-to-leading twist (2007)

Majumder, A., Nonaka, C., Bass, S. A.

The modification of the single inclusive spectrum of high transverse momentum ($p_T $) pions emanating from an ultra-relativistic heavy-ion collision is investigated. The deconfined sector is...

Hard and soft probe - medium interactions in a 3D hydro+micro approach at RHIC (2007)

Bass, S. A., Renk, T., Ruppert, J., Nonaka, C.

We utilize a 3D hybrid hydro+micro model for a comprehensive and consistent description of soft and hard particle production in ultra-relativistic heavy-ion collisions at RHIC. In the soft sector we...

Anomalous viscosity of an expanding quark-gluon plasma (2007)

Asakawa, M., Bass, S. A., Müller, B.

We argue that an expanding quark-gluon plasma has an anomalous viscosity, which arises from interactions with dynamically generated colour fields. The anomalous viscosity dominates over the...

Anomalous Viscosity of an Expanding Quark-Gluon Plasma (2006)

Asakawa, M., Bass, S. A., Müller, B.

We argue that an expanding quark-gluon plasma has an anomalous viscosity, which arises from interactions with dynamically generated color fields. We derive an expression for the anomalous viscosity...

Correlations in the Parton Recombination Model (2005)

Bass, S. A., Fries, R. J., Müller, B.

We describe how parton recombination can address the recent measurement of dynamical jet-like two particle correlations. In addition we discuss the possible effect realistic light-cone wave-functions...

Thermal Recombination: Beyond the Valence Quark Approximation (2005)

Muller, B., Fries, R. J., Bass, S. A.

Quark counting rules derived from recombination models agree well with data on hadron production at intermediate transverse momenta in relativistic heavy-ion collisions. They convey a simple picture...

Possible Resolutions of the D-Paradox (2005)

Nonaka, C., Muller, B., Bass, S. A., Asakawa, M.

We propose possible ways of explaining the net charge event-by-event fluctuations in Au+Au collisions at the Relativistic Heavy Ion Collider within a quark recombination model. We discuss various...

Correlated Emission of Hadrons from Recombination of Correlated Partons (2004)

Fries, R. J., Bass, S. A., Muller, B.

We discuss different sources of hadron correlations in relativistic heavy ion collisions. We show that correlations among partons in a quasi-thermal medium can lead to the correlated emission of...

Elliptic flow of resonances at RHIC: probing final state interactions and the structure of resonances (2003)

Nonaka, C., Asakawa, M., Bass, S. A., Fries, R. J., Mueller, B.

We propose the measurement of the elliptic flow of hadron resonances at the Relativistic Heavy Ion Collider as a tool to probe the amount of hadronic final state interactions for resonances at...

Hadron production in heavy ion collisions: Fragmentation and recombination from a dense parton phase (2003)

Fries, R. J., Muller, B., Nonaka, C., Bass, S. A.

We discuss hadron production in heavy ion collisions at RHIC. We argue that hadrons at transverse momenta P_T < 5 GeV are formed by recombination of partons from the dense parton phase created in...

Hadronization in heavy ion collisions: recombination or fragmentation? (2003)

Fries, R. J., Muller, B., Nonaka, C., Bass, S. A.

We show that hadron production in relativistic heavy ion collisions at transverse momenta larger than 2 GeV/c can be explained by the competition of two different hadronization mechanisms. Above 5...

Hadronization in heavy ion collisions: Recombination and fragmentation of partons (2003)

Fries, R. J., Bass, S. A., Muller, B., Nonaka, C.

We argue that the emission of hadrons with transverse momentum up to about 5 GeV/c in central relativistic heavy ion collisions is dominated by recombination, rather than fragmentation of partons....

Parton rescattering and screening in Au+Au collisions at RHIC (2002)

Bass, S. A., Mueller, B., Srivastava, D. K.

We study the microscopic dynamics of quarks and gluons in relativistic heavy ion collisions in the framework of the Parton Cascade Model. We use lowest order perturbative QCD cross sections with...

Probing Hadronization with Strangeness (2002)

Bass, S. A., Bleicher, M., Aichelin, J., Becattini, F., Keranen, A., Liu, F. M., ...

The Omega-bar/Omega ratio originating from string decays is predicted to be larger than unity in proton-proton interaction at SPS energies. The anti-omega dominance increases with decreasing beam...

Unlike particle correlations and the strange quark matter distillation process (2002)

Ardouin, D., Soff, Sven, Spieles, C., Bass, S. A., Stocker, H., Gourio, D., ...

We present a new technique for observing the strange quark matter distillation process based on unlike particle correlations. A simulation is presented based on the scenario of a two-phase...

Overpopulation of $\bar \Omega$ in pp collisions: a way to distinguish statistical hadronization from string dynamics (2001)

Bleicher, M, Liu Fu Ming, Keränen, A, Aichelin, Jörg, Bass, S A, Becattini, F, ...

The $\bar{\Omega}/\Omega$ ratio originating from string decays is predicted to be larger than unity in proton proton interactions at SPS energies ($E_{\rm lab}$=160 GeV). The anti-omega dominance...

Overpopulation of $\bar \Omega$ in pp collisions: a way to distinguish statistical hadronization from string dynamics (2001)

Bleicher, M., Liu, F. M., Keränen, A., Aichelin, J., Bass, S. A., Becattini, F., ...

The $\bar{\Omega}/\Omega$ ratio originating from string decays is predicted to be larger than unity in proton proton interactions at SPS energies ($E_{\rm lab}$=160 GeV). The anti-omega dominance...

Chemical freeze-out parameters at RHIC from microscopic model calculations (2001)

Bravina, L. V., Zabrodin, E. E., Bass, S. A., Faessler, A., Fuchs, C., Gorenstein, M. I., ...

The relaxation of hot nuclear matter to an equilibrated state in the central zone of heavy-ion collisions at energies from AGS to RHIC is studied within the microscopic UrQMD model. It is found that...

Local equilibrium in heavy-ion collisions: Microscopic analysis of a central cell versus infinite matter (2000)

Bravina, L. V., Zabrodin, E. E., Bass, S. A., Bleicher, M., Brandstetter, M., Soff, S., ...

We study the local equilibrium in the central $V = 125$ fm$^3$ cell in heavy-ion collisions at energies from 10.7 AGeV (AGS) to 160 AGeV (SPS) calculated in the microscopic transport model. In the...

Enhanced Strange Particle Yields - Signal of a Phase of Massless Particles ? (2000)

Soff, Sven, Zschiesche, D., Bleicher, M., Hartnack, C., Belkacem, M., Bravina, L., ...

The yields of strange particles are calculated with the UrQMD model for p,Pb(158 AGeV)Pb collisions and compared to experimental data. The yields are enhanced in central collisions if compared to...

Transition to resonance-rich matter in heavy ion collisions at RHIC energies (2000)

Bravina, L. V., Zabrodin, E. E., Bleicher, M., Bass, S. A., Brandstetter, M., Faessler, A., ...

The equilibration of hot and dense nuclear matter produced in the central region in central Au+Au collisions at $\sqrt{s}=200$ AGeV is studied within the microscopic transport model UrQMD. The...

Equation of state of resonance-rich matter in the central cell in heavy-ion collisions at $\sqrt{s}$=200 AGeV (2000)

Bravina, L. V., Zabrodin, E. E., Bass, S. A., Bleicher, M., Brandstetter, M., Faessler, A., ...

The equilibration of hot and dense nuclear matter produced in the central cell of central Au+Au collisions at RHIC ($\sqrt{s}=200$ AGeV) energies is studied within a microscopic transport model. The...

Bremsstrahlung from a Microscopic Model of Relativistic Heavy Ion Collisions (2000)

Wong, S. M. H., Belkacem, M., Kapusta, J. I., Bass, S. A., Bleicher, M., Stöcker, H.

We compute bremsstrahlung arising from the acceleration of individual charged baryons and mesons during the time evolution of high-energy Au+Au collisions at the Relativistic Heavy Ion Collider using...

Enhanced antiproton production in Pb(160 AGeV)+Pb reactions: evidence for quark gluon matter? (2000)

Bleicher, M., Belkacem, M., Bass, S. A., Soff, S., Stöcker, H.

The centrality dependence of the antiproton per participant ratio is studied in Pb(160 AGeV)+Pb reactions. Antiproton production in collisions of heavy nuclei at the CERN/SPS seems considerably...

Dynamics of Hot Bulk QCD Matter: from the Quark-Gluon Plasma to Hadronic Freeze-Out (2000)

Bass, S. A., Dumitru, A.

We introduce a combined macroscopic/microscopic transport approach employing relativistic hydrodynamics for the early, dense, deconfined stage of the reaction and a microscopic non-equilibrium model...

Global observables and secondary interactions in central Au+Au reactions at $\sqrt{s}=200$ AGeV (1999)

Bleicher, M., Bass, S. A., Bravina, L. V., Greiner, W., Soff, S., Stöcker, H., ...

The Ultra-relativistic Quantum Molecular Dynamics model (UrQMD) is used to study global observables in central reactions of Au+Au at $\sqrt{s}=200$ AGeV (RHIC). Strong stopping governed by massive...

Relativistic Hadron-Hadron Collisions in the Ultra-Relativistic Quantum Molecular Dynamics Model (UrQMD) (1999)

Bleicher, M., Zabrodin, E., Spieles, C., Bass, S. A., Ernst, C., Soff, S., ...

Hadron-hadron collisions at high energies are investigated in the Ultra-relativistic-Quantum-Molecular-Dynamics approach (UrQMD). This microscopic transport model is designed to study pp, pA and A+A...

K-Factors in Parton Cascades at RHIC and SPS (1999)

Bass, S. A., Muller, B.

Different treatments for the inclusion of higher-order perturbative QCD corrections in parton based transport models of relativistic heavy-ion collisions are studied and their influence on...

Transport calculation of dilepton production at ultrarelativistic energies (1999)

Ernst, C., Bass, S. A., Soff, S., Stöcker, H., Greiner, W.

Dilepton spectra are calculated within the microscopic transport model UrQMD and compared to data from the CERES experiment. The invariant mass spectra in the region 300 MeV < M < 600 MeV depend...

Equilibrium and non-equilibrium effects in relativistic heavy ion collisions (1999)

Bravina, L. V., Zabrodin, E. E., Gorenstein, M. I., Bass, S. A., Belkacem, M., Bleicher, M., ...

The hypothesis of local equilibrium (LE) in relativistic heavy ion collisions at energies from AGS to RHIC is checked in the microscopic transport model. We find that kinetic, thermal, and chemical...

Local equilibrium in heavy ion collisions. Microscopic model versus statistical model analysis (1999)

Bravina, L. V., Zabrodin, E. E., Gorenstein, M. I., Bass, S. A., Belkacem, M., Bleicher, M., ...

The assumption of local equilibrium in relativistic heavy ion collisions at energies from 10.7 AGeV (AGS) up to 160 AGeV (SPS) is checked in the microscopic transport model. Dynamical calculations...

RHIC predictions from the UrQMD model (1999)

Bleicher, M., Bass, S. A, Stöcker, H., Greiner, W.

The Ultra-relativistic Quantum-Molecular-Dynamics model (UrQMD) is used to study central Pb+Pb reactions at RHIC ($\sqrt{s}=200$ AGeV). The computed collision spectrum reveals that the major part...

Deuterons and space-momentum correlations in high energy nuclear collisions (1999)

Monreal, B., Bass, S. A., Bleicher, M., Esumi, S., Greiner, W., Li, Q., ...

Using a microscopic transport model together with a coalescence after-burner, we study the formation of deuterons in Au + Au central collisions at $\sqrt{s}=200 AGeV$. It is found that the deuteron...

Physics opportunities at RHIC and LHC (1999)

Scherer, S., Bass, S. A., Belkacem, M., Bleicher, M., Brachmann, J., Dumitru, A., ...

Nonequilibrium models (three-fluid hydrodynamics, UrQMD, and quark molecular dynamics) are used to discuss the uniqueness of often proposed experimental signatures for quark matter formation in...

Hadronic freeze-out following a first order hadronization phase transition in ultrarelativistic heavy-ion collisions (1999)

Bass, S. A., Dumitru, A., Bleicher, M., Bravina, L., Zabrodin, E., Stoecker, H., ...

We analyze the hadronic freeze-out in ultra-relativistic heavy ion collisions at RHIC in a transport approach which combines hydrodynamics for the early, dense, deconfined stage of the reaction with...

Analysis of reaction dynamics at RHIC in a combined parton/hadron transport approach (1999)

Bass, S. A., Hofmann, M., Bleicher, M., Bravina, L., Zabrodin, E., Stoecker, H., ...

We introduce a transport approach which combines partonic and hadronic degrees of freedom on an equal footing and discuss the resulting reaction dynamics. The initial parton dynamics is modeled in...

Modelling J/psi production and absorption in a microscopic nonequilibrium approach (1999)

Spieles, C., Vogt, R., Gerland, L., Bass, S. A., Bleicher, M., Stoecker, H., ...

Charmonium production and absorption in heavy ion collisions is studied with the Ultrarelativisitic Quantum Molecular Dynamics model. We compare the scenario of universal and time independent...

Direct Emission of multiple strange baryons in ultrarelativistic heavy-ion collisions from the phase boundary (1999)

Dumitru, A., Bass, S. A., Bleicher, M., Stöcker, H., Greiner, W.

We discuss a model for the space-time evolution of ultrarelativistic heavy-ion collisions which employs relativistic hydrodynamics within one region of the forward light-cone, and microscopic...

Distinguishing Hadronic Cascades from Hydrodynamic Models in Pb(160 AGeV)+Pb Reactions by Impact Parameter Variation (1998)

Bleicher, M., Reiter, M., Dumitru, A., Brachmann, J., Spieles, C., Bass, S. A., ...

We propose to study the impact parameter dependence of the anti-Lambda/anti-Proton ratio in Pb(160AGeV)+Pb reactions. The anti-Lambda/anti-Proton ratio is a sensible tool to distinguish between...

Modelling the many-body dynamics of heavy ion collisions: Present status and future perspective (1998)

Hartnack, C., Puri, Rajeev K., Aichelin, J., Konopka, J., Bass, S. A., Stoecker, H., ...

Basic problems of the semiclassical microscopic modelling of strongly interactingsystems are discussed within the framework of Quantum Molecular Dynamics (QMD). This model allows to study the...

Reaction dynamics in Pb + Pb at the CERN/SPS (1998)

Bass, S A, Spieles, C, Greiner, W, Stöcker, H, Soff, S, Bravina, L V, ...

We analyze the reaction dynamics of central Pb+Pb collisions at 160 GeV/nucleon. First we estimate the energy density pile-up at mid-rapidity and calculate its excitation function: The energy density...

Reaction dynamics in Pb+Pb at the CERN/SPS: from partonic degrees of freedom to freeze-out (1998)

Bass, S. A., Weber, H., Ernst, C., Bleicher, M., Belkacem, M., Bravina, L., ...

We analyze the reaction dynamics of central Pb+Pb collisions at 160 GeV/nucleon. First we estimate the energy density pile-up at mid-rapidity and calculate its excitation function: The energy density...

Reaction dynamics in Pb + Pb at the CERN/SPS: from partonic degrees of freedom to freeze-out (1998)

Bass, S A, Weber, H, Ernst, C, Bleicher, M, Belkacem, M, Bravina, L V, ...

We analyze the reaction dynamics of central Pb+Pb collisions at 160 GeV/nucleon. First we estimate the energy density pile-up at mid-rapidity and calculate its excitation function: The energy density...

J/psi suppression in heavy ion collisions - interplay of hard and soft QCD processes (1998)

Spieles, C., Vogt, R., Gerland, L., Bass, S. A., Bleicher, M., Frankfurt, L., ...

We study J/psi suppression in AB collisions assuming that the charmonium states evolve from small, color transparent configurations. Their interaction with nucleons and nonequilibrated, secondary...

Local Thermal and Chemical Equilibration and the Equation of State in Relativistic Heavy Ion Collisions (1998)

Bravina, L. V., Brandstetter, M., Gorenstein, M. I., Zabrodin, E. E., Belkacem, M., Bleicher, M., ...

Thermodynamical variables and their time evolution are studied for central relativistic heavy ion collisions from 10.7 to 160 AGeV in the microscopic Ultrarelativistic Quantum Molecular Dynamics...

Signatures of Quark-Gluon-Plasma formation in high energy heavy-ion collisions: A critical review (1998)

Bass, S. A., Gyulassy, M., Stoecker, H., Greiner, W.

A critical review on signatures of Quark-Gluon-Plasma formation is given and the current (1998) experimental status is discussed. After giving an introduction to the properties of QCD matter in both,...

Dissociation rates of J/psi's with comoving mesons - thermal vs. nonequilibrium scenario (1998)

Spieles, C., Vogt, R., Gerland, L., Bass, S. A., Bleicher, M., Stoecker, H., ...

We study J/psi dissociation processes in hadronic environments. The validity of a thermal meson gas ansatz is tested by confronting it with an alternative, nonequilibrium scenario. Heavy ion...

Excitation Function of Energy Density and Partonic Degrees of Freedom in Relativistic Heavy Ion Collisions (1998)

Weber, H., Ernst, C., Bleicher, M., Bravina, L., Stoecker, H., Greiner, W., ...

We estimate the energy density pile-up at mid-rapidity in central Pb+Pb collisions from 2 - 200 GeV/nucleon. The energy density is decomposed into hadronic and partonic contributions. A detailed...

Equation of State, Spectra and Composition of Hot and Dense Infinite Hadronic Matter in a Microscopic Transport Model (1998)

Belkacem, M., Brandstetter, M., Bass, S. A., Bleicher, M., Bravina, L., Gorenstein, M. I., ...

Equilibrium properties of infinite relativistic hadron matter are investigated using the Ultrarelativistic Quantum Molecular Dynamics (UrQMD) model. The simulations are performed in a box with...