Steffen A. Bass


Associate Chair for Teaching

261D Physics, Durham, NC 27708
Campus Box: 
(919) 660-2479
(919) 660-2525


Energy loss, hadronization, and hadronic interactions of heavy flavors in relativistic heavy-ion collisions
Physical Review C (2015)

Alternative ansatz to wounded nucleon and binary collision scaling in high-energy nuclear collisions
Physical Review C (2015)

Quantifying properties of hot and dense QCD matter through systematic model-to-data comparison
Physical Review C (2015)

Charm quark energy loss in infinite QCD matter using a parton cascade model
Physical Review C (2015)

Dynamical evolution, hadronization and angular de-correlation of heavy flavor in a hot and dense QCD medium
Nuclear Physics A (2014)

Dynamical evolution, hadronization and angular de-correlation of heavy flavor in a hot and dense QCD medium
Nuclear Physics A (2014)

Heavy-flavor observables at RHIC and LHC
Nuclear Physics A (2014)

Center domains and their phenomenological consequences in ultrarelativistic heavy ion collisions
Nuclear Physics A (2014)

Heavy flavor dynamics in QGP and hadron gas
Nuclear Physics A (2014)

Prof. Bass' main area of research is strong interaction theory, in particular the study of highly excited many-body systems governed by the laws of Quantum-Chromo-Dynamics (QCD).

It is believed that shortly after the creation of the universe in the Big Bang the entire universe existed as a hot and dense plasma of fundamental particles that interacted via a single unified force. As the primordial fire ball expanded and consequentially cooled, the four fundamental forces that we observe today became distinct. The relative importance of these four forces, the strong nuclear, weak nuclear, electromagnetic and gravitational force, in shaping the universe varied as the energy-matter density evolved. In this cosmic picture, about a microsecond after the primordial explosion, the universe was in a state called the Quark Gluon Plasma (QGP) in which quarks and gluons, the basic constituents of the strong interaction force, QCD, roamed freely. Due to the rapid expansion of the universe, this plasma went through a phase transition to form hadrons - most importantly nucleons - which constitute the building blocks of matter as we know it today.

It has been only in the last ten years that accelerators have been in operation that give us the capabilities to create the conditions of temperature and density in the laboratory that are favorable for the QGP to exist. The Relativistic Heavy-Ion Collider (RHIC) at Brookhaven National Laboratory and the accompaniment of detector systems were built specifically to observe and study this phase of matter. Similar studies have recently commenced at the CERN Large Hadron Collider. The experiments at RHIC have discovered a new form of ultra-dense matter with unprecedented properties, a plasma composed of unbound quarks and gluons, that appears to behave as a nearly ``perfect liquid.''

The central problem in the study of the QGP is that its lifetime is so short that only the ashes of its decay (in the form of hadrons) can be detected. In addition, the deconfined quanta of a QGP are not directly observable due to the fundamental confining property of the physical quantum chromodynamics vacuum, i.e. the properties of the underlying quantum-field theory governing its interactions. One of the main tasks in relativistic heavy-ion research is to find clear and unambiguous connections between the transient (quark-gluon) plasma state and the experimentally observable hadronic final state.

Prof. Bass is actively involved in developing models for the dynamics of such highly energetic heavy-ion collisions. His research involves the application of transport theory, statistical mechanics, heavy-ion phenomenology, as well as the fundamental laws of QCD. Only through the application of dynamical models of heavy-ion collisions and the comparison of their predictions with data, may a link be formed between the observable hadronic and leptonic final state of the heavy-ion reaction and the transient deconfined state of quarks and gluons.


Steffen A. Bass joined the faculty of Duke University in 2000 as Assistant Professor with subsequent promotions to Associate Professor in 2008 and Professor in 2012. From 2000 to 2005 he also held a position as RIKEN-BNL Research Center Fellow. He received his Ph.D. in Theoretical Physics in 1997 from the J.W. Goethe University in Frankfurt, Germany, and subsequently held postdoctoral appointments at Duke and Michigan State University (as Visiting Assistant Professor).

Professor Bass' main research interests are the physics of relativistic heavy-ion collisions, the phenomenology and transport properties of the Quark-Gluon-Plasma and knowledge extraction from large scale data sets via computational modeling. He is best known for his work developing a variety of transport models for the description of ultra-relativistic heavy-ion collisions, such as UrQMD and hybrid RFD+Boltzmann models, as well as his contributions to the parton recombination model, the phenomenology of the QGP and the shear viscosity of QCD matter.

Bass was awarded a DOE Outstanding Junior Investigator Award in 2003 and is a member of the Division of Nuclear Physics and the Division of Computational Physics of the American Physical Society. He served on the DNP Program Committee in 2010 and 2011 and was elected Fellow of the American Physical Society in 2014. He has published more than 140 peer-reviewed articles with over 8,000 citations and an h-factor of 43. He is a member of the Editorial Board of Journal of Physics G: Nuclear and Particle Physics and recently served as chair of the 2012 Hot & Dense QCD White Paper Writing Committee.

Dr. Phil. Nat. - Johann Wolfgang Goethe Universitaet, Frankfurt, Germany
Ph.D. - Johann Wolfgang Goeth Universitat Frankfurt Am Main (Germany)
Diplom-Physiker - Johann Wolfgang Goethe Universitaet Frankfurt, Germany
M.S. - Johann Wolfgang Goeth Universitat Frankfurt Am Main (Germany)
2014 Fellow of the American Physical Society, American Physical Society
2003 Outstanding Junior Investigator Award, US Department of Energy
1997 Feodor-Lynen Award, Alexander v. Humboldt Foundation
1993 W.E. Heraeus Award, W.E. Heraeus Foundation