Paul Scherrer Institute

About: Paul Scherrer Institute is a facility organization based out in Villigen, Switzerland. It is known for research contribution in the topics: Neutron & Large Hadron Collider. The organization has 9248 authors who have published 23984 publications receiving 890129 citations. The organization is also known as: PSI.

Performance of photon reconstruction and identification with the CMS detector in proton-proton collisions at √s = 8 TeV

Abstract: 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.

Synthesis and crystal growth of Cs 0.8 (FeSe 0.98 ) 2 :a new iron-based superconductor with T c = 27 K

Abstract: We report on the synthesis of large single crystals of a new FeSe layer superconductor Cs0.8(FeSe0.98)2. X-ray powder diffraction, neutron powder diffraction and magnetization measurements have been used to compare the crystal structure and the magnetic properties of Cs0.8(FeSe0.98)2 with those of the recently discovered potassium intercalated system KxFe2Se2. The new compound, Cs0.8(FeSe0.98)2, shows a slightly lower superconducting transition temperature (Tc = 27.4 K) in comparison to 29.5 in (K0.8(FeSe0.98)2). The volume of the crystal unit cell increases by replacing K by Cs—the c parameter grows from 14.1353(13) to 15.2846(11) A. For the alkali metal intercalated layered compounds known so far, (K0.8Fe2Se2 and Cs0.8(FeSe0.98)2), the Tc dependence on the anion height (distance between Fe layers and Se layers) was found to be analogous to those reported for As-containing Fe superconductors and Fe(Se1 − xChx), where Ch = Te, S.