Stepping outside the neighborhood of T_c at LHC

TL;DR

This paper discusses the unique physics opportunities at the LHC for heavy-ion collisions, emphasizing qualitative differences in thermal physics near the critical temperature T_c compared to higher temperatures, which are accessible only at the LHC.

Contribution

It highlights the importance of exploring the temperature range near T_c at the LHC, where qualitative differences in thermal physics are predicted by lattice QCD, beyond the extended kinematic reach.

Findings

Lattice QCD predicts qualitative differences in thermal physics near T_c.

Higher temperature physics (T > 400-500 MeV) is only accessible at the LHC.

Understanding physics near T_c can reveal new phenomena not seen at RHIC.

Abstract

"As you are well aware, many in the RHIC community are interested in the LHC heavy-ion program, but have several questions: What can we learn at the LHC that is qualitatively new? Are collisions at LHC similar to RHIC ones, just with a somewhat hotter/denser initial state? If not, why not? These questions are asked in good faith, and this talk is an opportunity to answer them directly to much of the RHIC community." With these words, the organizers of Quark Matter 2009 in Knoxville invited me to discuss the physics opportunities for heavy ion collisions at the LHC without recalling the standard arguments, which are mainly based on the extended kinematic reach of the machine. In response, I emphasize here that lattice QCD indicates characteristic qualitative differences between thermal physics in the neighborhood of the critical temperature (T_c < T < 400 - 500 MeV) and thermal physics at higher temperatures (T > 400-500 MeV), for which the relevant energy densities will be solely attainable at the LHC.