Proton structure from HERA to LHC
Proceedings of 40th International Symposium on Multiparticle Dynamics, ISMD 2010 (2011)
Abstract:
The kinematic region covered by the LHC experiments probes low values of Bjorken-x. At the scale relevant for W and Z production the central rapidity region covers 10-3 < × < 10-1, for √s = 7 TeV. This means that it is the HERA data which give the most insight into the behaviour of parton distribution functions (PDFs) for the early phase of running at the LHC. The H1 and ZEUS experiments are combining their data so as to provide a legacy of HERA results. The present status of the data combinations and the impact of these data on our knowledge of parton distribution functions is explored.Measurement of the transverse momentum distribution of Z/γ* bosons in proton-proton collisions at s=7 TeV with the ATLAS detector
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 705:5 (2011) 415-434
Abstract:
A measurement of the Z/γ* transverse momentum (pTZ) distribution in proton-proton collisions at s=7 TeV is presented using Z/γ*→e+e- and Z/γ*→μ+μ- decays collected with the ATLAS detector in data sets with integrated luminosities of 35 pb-1 and 40 pb-1, respectively. The normalized differential cross sections are measured separately for electron and muon decay channels as well as for their combination up to pTZ of 350 GeV for invariant dilepton masses 66 GeVSearch for the Standard Model Higgs boson in the two photon decay channel with the ATLAS detector at the LHC
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 705:5 (2011) 452-470
Abstract:
A search for the Standard Model Higgs boson in the two photon decay channel is reported, using 1.08 fb-1 of proton-proton collision data at a centre-of-mass energy of 7 TeV recorded by the ATLAS detector. No significant excess is observed in the investigated mass range of 110-150 GeV. Upper limits on the cross-section times branching ratio of between 2.0 and 5.8 times the Standard Model prediction are derived for this mass range. © 2011 CERN.Search for the Standard Model Higgs boson in the decay channel H→ZZ(*)→4ℓ with the ATLAS detector
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 705:5 (2011) 435-451
Abstract:
A search for the Standard Model Higgs boson in the decay channel H→ZZ(*)→ℓ+ℓ-ℓ'+ℓ'-, where ℓ=e, μ, is presented. Proton-proton collision data at s=7TeV recorded with the ATLAS detector and corresponding to an average integrated luminosity of 2.1fb-1 are compared to the Standard Model expectations. Upper limits on the production cross section of a Standard Model Higgs boson with a mass between 110 and 600GeV are derived. The observed (expected) 95% confidence level upper limit on the production cross section for a Higgs boson with a mass of 194 GeV, the region with the best expected sensitivity for this search, is 0.99 (1.01) times the Standard Model prediction. The Standard Model Higgs boson is excluded at 95% confidence level in the mass ranges 191-197, 199-200 and 214-224 GeV. © 2011 CERN.Measurement of the WZ production cross section and limits on anomalous triple gauge couplings in proton-proton collisions at sqrt(s) = 7 TeV with the ATLAS detector
ArXiv 1111.557 (2011)