Can minimum-bias distributions on transverse energy test hadron   production models?
  A recent study reports measurements of transverse-energy $E_t$ distributions at mid-rapidity for several high-energy nuclear collision systems. The $E_t$ data are analyzed in the context of constituent-quark (CQ) participants estimated with a Glauber-model simulation. The study concludes that systematic variations of hadron and $E_t$ yields previously interpreted in terms of a two-component soft+hard model (TCM) of hadron production including a dijet (hard) contribution are actually the result of CQ participant trends with only soft production. It is claimed that deviations from linear scaling with the number of nucleon participants of hadron yields vs A-A centrality do not actually arise from dijet production as previously assumed. In the present study we examine the new $E_t$ data in the context of the TCM and compare those results with previous differential spectrum and minimum-bias correlation analysis. We present substantial evidence supporting a significant dijet contribution to all high-energy nuclear collisions consistent with the TCM and conclude that the $E_t$ data, given their systematic uncertainties, fail to support claimed CQ model interpretations. 
Thomas A. Trainor
hep-ph