Search for new resonances in W γ and Z γ final states in pp collisions at √ s = 8 TeV with the ATLAS detector .ATLAS Collaboration a r t i c l e i n f o a b s t r a c t This Letter presents a search for new resonances decaying to final states with a vector boson produced in association with a high transverse momentum photon, V γ , with V = W (→ ν) or Z (→ + − ), where = e or μ. The measurements use 20.3 fb −1 of proton-proton collision data at a center-of-mass energy of √ s = 8 TeV recorded with the ATLAS detector. No deviations from the Standard Model expectations are found, and production cross section limits are set at 95% confidence level. Masses of the hypothetical a T and ω T states of a benchmark Low Scale Technicolor model are excluded in the ranges [275, 960] GeV and [200, 700] ∪ [750, 890] GeV, respectively. Limits at 95% confidence level on the production cross section of a singlet scalar resonance decaying to Z γ final states have also been obtained for masses below 1180 GeV. Published by Elsevier B.V. This is an open access article under the CC BY license

A measurement of the cross section for the inclusive production of isolated prompt photons in pp collisions at a center-of-mass energy ffiffi ffi s p ¼ 7 TeV is presented. The measurement covers the pseudorapidity ranges j j < 1:37 and 1:52 j j < 1:81 in the transverse energy range 15 E T < 100 GeV. The results are based on an integrated luminosity of 880 nb À1 , collected with the ATLAS detector at the Large Hadron Collider. Photon candidates are identified by combining information from the calorimeters and from the inner tracker. Residual background in the selected sample is estimated from data based on the observed distribution of the transverse isolation energy in a narrow cone around the photon candidate. The results are compared to predictions from next-to-leading-order perturbative QCD calculations.

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Measurements of fiducial and differential cross sections are presented for Higgs boson production in proton-proton collisions at a centre-of-mass energy of √ s = 8 TeV. The analysis is performed in the H → γγ decay channel using 20.3 fb −1 of data recorded by the ATLAS experiment at the CERN Large Hadron Collider. The signal is extracted using a fit to the diphoton invariant mass spectrum assuming that the width of the resonance is much smaller than the experimental resolution. The signal yields are corrected for the effects of detector inefficiency and resolution. The pp → H → γγ fiducial cross section is measured to be 43.2 ±9.4 (stat.) +3.2 −2.9 (syst.) ±1.2 (lumi) fb for a Higgs boson of mass 125.4 GeV decaying to two isolated photons that have transverse momentum greater than 35% and 25% of the diphoton invariant mass and each with absolute pseudorapidity less than 2.37. Four additional fiducial cross sections and two cross-section limits are presented in phase space regions that test the theoretical modelling of different Higgs boson production mechanisms, or are sensitive to physics beyond the Standard Model. Differential cross sections are also presented, as a function of variables related to the diphoton kinematics and the jet activity produced in the Higgs boson events. The observed spectra are statistically limited but broadly in line with the theoretical expectations.