Search for pair production of second generation scalar leptoquarks in p over(p, ̄) collisions at sqrt(s) = 1.96 TeV
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 636:3-4 (2006) 183-190
Abstract:
We report on a search for the pair production of second generation scalar leptoquarks ( LQ2) in p over(p, ̄) collisions at the center-of-mass energy sqrt(s) = 1.96 TeV, using data corresponding to an integrated luminosity of 294 ± 19 pb-1 recorded with the DØ detector. No evidence for a leptoquark signal in the LQ2 over(LQ, -)2 → μ q μ q channel has been observed, and upper bounds on the product of cross section times branching fraction were set. This yields lower mass limits of mLQ2 > 247 GeV / c2 for β = B ( LQ2 → μ q ) = 1 and mLQ2 > 182 GeV / c2 for β = 1 / 2. Combining these limits with previous DØ results, the lower limits on the mass of a second generation scalar leptoquark are mLQ2 > 251 GeV / c2 and mLQ2 > 204 GeV / c2 for β = 1 and β = 1 / 2, respectively. © 2006 Elsevier B.V. All rights reserved.Search for the Higgs Boson in H→WW(*) decays in pp̄ collisions at s=1.96TeV
Physical Review Letters 96:1 (2006)
Abstract:
We present a search for the standard model Higgs boson in H→WW(*) decays with e+e-, e±μ, and μ+μ- final states in pp̄ collisions at a center-of-mass energy of s=1.96TeV. The data, collected from April 2002 to June 2004 with the D0 detector, correspond to an integrated luminosity of 300-325pb-1, depending on the final state. The number of events observed is consistent with the expectation from backgrounds. Limits from the combination of all three channels on the Higgs boson production cross section times branching ratio σ×BR(H→WW(*)) are presented. © 2006 The American Physical Society.Direct limits on the Bs0 oscillation frequency
Physical Review Letters 97:2 (2006)
Abstract:
We report results of a study of the Bs0 oscillation frequency using a large sample of Bs0 semileptonic decays corresponding to approximately 1fb-1 of integrated luminosity collected by the D0 experiment at the Fermilab Tevatron Collider in 2002-2006. The amplitude method gives a lower limit on the Bs0 oscillation frequency at 14.8ps-1 at the 95% C.L. At Δms=19ps-1, the amplitude deviates from the hypothesis A=0 (1) by 2.5 (1.6) standard deviations, corresponding to a two-sided C.L. of 1% (10%). A likelihood scan over the oscillation frequency, Δms, gives a most probable value of 19ps-1 and a range of 17<Δms<21ps-1 at the 90% C.L., assuming Gaussian uncertainties. This is the first direct two-sided bound measured by a single experiment. If Δms lies above 22ps-1, then the probability that it would produce a likelihood minimum similar to the one observed in the interval 16-22ps-1 is (5.0±0.3)%. © 2006 The American Physical Society.Search for resonant second generation slepton production at the Fermilab tevatron
Physical Review Letters 97:11 (2006)
Abstract:
We present a search for supersymmetry in the R-parity violating resonant production and decay of smuons and muon sneutrinos in the channels, 2,3,40. We analyzed 0.38fb-1 of integrated luminosity collected between April 2002 and August 2004 with the D0 detector at the Fermilab Tevatron Collider. The observed number of events is in agreement with the standard model expectation, and we calculate 95% C.L. limits on the slepton production cross section times branching fraction to gaugino plus muon, as a function of slepton and gaugino masses. In the framework of minimal supergravity, we set limits on the coupling parameter, extending significantly previous results obtained in Run I of the Tevatron and at the CERN LEP collider. © 2006 The American Physical Society.Limits on anomalous trilinear gauge couplings from WW→e+e-, WW→e±μ∓, and WW→μ+μ- events from pp collisions at √s=1.96 TeV
PHYSICAL REVIEW D 74:5 (2006) ARTN 057101