Throughout my career, I’ve had an interest in developing models to understand various aspects of particle production and correlations in hadronic and nuclear collisions. Here are various papers I have written or co-authored along these lines:

  • Small System Collectivity in Relativistic Hadronic and Nuclear Collisions (2007), co-authored with Jamie Nagle. This is a review article examining the experimental evidence for and theoretical explanations of the collective behavior observed in nuclear collisions. Our conclusion:

    In summary, ample theoretical arguments developed over the past decade suggest that viscous relativistic hydrodynamics can be applied to describe particle production and flow in p+p and p+A collisions at high energies…The insights derived from this ongoing work have greatly extended the regimes in which we can apply properly-formulated relativistic viscous hydrodynamics, with implications for many-body strongly coupled systems in other fields of physics.

  • The Fluid Nature of Quark-Gluon Plasma (2007). A status report on the field at the time. I am pleased that the concluding sentence of the abstract “The current status of the RHIC experimental studies is presented, with a special emphasis on the fluid properties of the created matter, which may in fact be the most perfect fluid ever studied in the laboratory” has held up rather well over time. 
  • Imaging the final-state phase space in heavy-ion collisions (1998). This was the conference proceedings for the Nucleus-Nucleus 1997 conference, in which I noted the utility of Gaussian functions with correlated coordinate and momentum space emission functions for analytically testing various Wigner function approximations in calculating HBT correlations. It should have been written up as a real paper, but this conference was just a few weeks before I became PHENIX spokesperson, so that never happened. 
  • Monte Carlo Calculational Methods for the Generation of Events with Bose-Einstein Correlations (1986). In this paper I developed a Monte Carlo (Metropolis) procedure for generating n-pion events with complete Bose-Einstein correlations between the particles. This is amenable to direct calculation for values of n up to ~20 (using the computer technology of the time!), beyond that required a Monte Carlo of the Monte Carlo, but this did succeed in producing nice “speckle” patterns of pion clusters and the correct negative-binomial phase space clustering.  
  • KNO Scaling Isn’t What It Used To Be (1986). This is really a combination of two minor observations: 1) What people commonly refer to as KNO scaling (scaling of the higher-order moments with the mean multiplicity) was really an approximation to what Koba, Nielsen and Olesen really predicted (scaling of the factorial moments, as found in negative-binomial distributions) and 2) Assuming particle production of negative-binomial distributions of parents, binomial (random) sampling of children was also negative-binomial, and that this mechanism provided a nice description of the neutral-charged correlation coefficient variation with multiplicity.