Performance of Photon Reconstruction and Identification with the CMS Detector in Proton-Proton Collisions at sqrt(s) = 8 TeV

• Main Author: CMS collaboration (2145 authors)
• Publication Date: 2015
• Other Authors: Hollar, Jonathan, Nayak, Aruna, Bargassa, Pedrame, Beirão Da Cruz E Silva, Cristóvão, Faccioli, Pietro, Ferreira Parracho, Pedro Guilherme, Gallinaro, Michele, Lloret Iglesias, Lara, Nguyen, Federico, Rodrigues Antunes, Joao, Seixas, Joao, Varela, Joao, Vischia, Pietro, David Tinoco Mendes, Andre, Silva, Pedro, Musella, Pasquale, Pela, Joao, Leonardo, Nuno
• Format: Article
• Language: eng
• Source: Repositórios Científicos de Acesso Aberto de Portugal (RCAAP)
• Download full: http://dx.doi.org/10.1088/1748-0221/10/08/P08010; http://hdl.handle.net/10400.26/26774

A description is provided of the performance of the CMS detector for photon reconstruction and identification in proton-proton collisions at a centre-of-mass energy of 8 TeV at the CERN LHC. Details are given on the reconstruction of photons from energy deposits in the electromagnetic calorimeter (ECAL) and the extraction of photon energy estimates. The reconstruction of electron tracks from photons that convert to electrons in the CMS tracker is also described, as is the optimization of the photon energy reconstruction and its accurate modelling in simulation, in the analysis of the Higgs boson decay into two photons. In the barrel section of the ECAL, an energy resolution of about 1% is achieved for unconverted or late-converting photons from H→γγ decays. Different photon identification methods are discussed and their corresponding selection efficiencies in data are compared with those found in simulated events.