In this article, we report the inclusive charged hadron and isolated photon spectra at $\sqrt{ s_{ NN}}=2.76$ 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 $\sqrt{ s}=2.76$ 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 $\sqrt{ s_{ NN}}=2.76$ TeV produce a strongly interacting colored medium.
Categories: nucl-ex