High pT inclusive hadron and photon spectra in pp and PbPb collisions

Abstract

In this article, we report the inclusive charged hadron and isolated photon spectra at √ s NN = 2.76 TeV PbPb collisions measured with the CMS detector at LHC. Charged particle momentum spectra are compared to a constructed reference measurement of proton-proton collisions at √ s = 2.76 TeV by using a combination of x T scaling and direct interpolation at fixed p T . Photon results are compared to next to leading order calculations at the same center of mass energy. Nuclear modification factors (R AA ) are calculated to study the properties of the medium. While a large suppression is observed in the charged particle R AA at high transverse momentum, isolated photons show no modifications, revealing that PbPb collisions at √ s NN = 2.76 TeV produce a strongly interacting colored medium.