Scaled momentum distributions for K0s and Lambda/bar Lambda in DIS at HERA
(2011)
Measurement of the t dependence in exclusive photoproduction of Upsilon(1S) mesons at HERA
(2011)
Discovery reach for generic supersymmetry at the LHC: MT2 versus missing transverse momentum selections for pMSSM searches
Journal of High Energy Physics 2011:7 (2011)
Abstract:
Different search strategies for supersymmetry have been employed by the LHC general-purpose experiments using early data. As proven by their early results, these strategies are promising, but raise the question of how well they will generalize for the future. We address this question by studying two thousand phenomenological minimal supersymmetric standard model parameter space points that come from a fit to indirect and cosmological data. We examine the 5σ discoverability of the points employing a typical ATLAS-type search based on missing transverse momentum (MET), a search based on an optimised M T2cut and a combination of the two, taking into account standard model backgrounds. The discovery reach of the strategies can depend strongly on the systematic uncertainty in the background, subject to the stringency of the cuts and the details of the background simulation. By combining the MET and MT2 based strategies, with an integrated luminosity of 1 fb -1 (10 fb-1) at 7TeV, 4-8% (42%) of the points are discoverable, depending on the systematic uncertainty on the background. At 14TeV and with 10 fb-1, 96% of the points are discoverable. While the majority of points can be discovered by both strategies at √s = 14 TeV and with 1 fb-1, there are some that are left undiscovered by a MET search strategy, but which are discovered by the MT2 strategy, and vice versa, therefore it is essential that one performs both in parallel. We discuss some of the factors that can make points more difficult to observe. © SISSA 2011.Measurement of the differential cross-sections of inclusive, prompt and non-prompt J/Ψ production in proton-proton collisions at √s=7 TeV
Nuclear Physics B 850:3 (2011) 387-444
Abstract:
The inclusive J/Ψ production cross-section and fraction of J/Ψ mesons produced in B-hadron decays are measured in proton-proton collisions at √s=7 TeV with the ATLAS detector at the LHC, as a function of the transverse momentum and rapidity of the J/Ψ, using 2.3 pb-1 of integrated luminosity. The cross-section is measured from a minimum pT of 1 GeV to a maximum of 70 GeV and for rapidities within |y|<2.4 giving the widest reach of any measurement of J/Ψ production to date. The differential production cross-sections of prompt and non-prompt J/Ψ are separately determined and are compared to Colour Singlet NNLO*, Colour Evaporation Model, and FONLL predictions. © 2011 CERN.Properties of jets measured from tracks in proton-proton collisions at center-of-mass energy √s=7TeV with the ATLAS detector
Physical Review D - Particles, Fields, Gravitation and Cosmology 84:5 (2011)