Mr Risto Paatelainen (University of Jyvaskyla, Finland)
The EKRT model  which combines pQCD minijet production with the saturation of produced gluons and (ideal) hydrodynamics, has predicted the measured multiplicities in central A + A collisions both at RHIC and LHC remarkably well . Also the published pT spectra of bulk hadrons (at RHIC) have been reproduced quite nicely . We now bring this closed framework to NLO as rigorously as possible. In particular, we calculate the minijet transverse energy production by using the latest knowledge of nuclear parton distributions (nPDFs), the NLO sets EPS09 , and discuss how the nPDF uncertainties propagate into the computed hydrodynamical initial conditions as well as observable multiplicities. Regarding the NLO minijet production, we develop a new set of infra-red safe measurement functions and study their effect on the multiplicity systematics from RHIC to LHC. Our main goal here is to quantify the theoretical uncertainties and the predictive power of this NLO pQCD + saturation + hydrodynamics -framework.  K. J. Eskola, K. Kajantie, P. V. Ruuskanen and K. Tuominen Nuc. Phys. B 570 (2000) 379.  K. J. Eskola, P. V. Ruuskanen, S. S. Rasanen and K. Tuominen, Nucl. Phys. A 696 (2001) 715.  K. J. Eskola, H. Honkanen, H. Niemi, P. V. Ruuskanen and S. S. Rasanen, Phys. Rev. C 72 (2005) 044904  K. J. Eskola, H. Paukkunen and C. A. Salgado, JHEP 0904 (2009) 065.