Measurement of the polarization of the Υ(1S) and Υ(2S) states in pp̄ collisions at s=1.96TeV
Physical Review Letters 101:18 (2008)
Abstract:
We present a study of the polarization of the Υ(1S) and Υ(2S) states using a 1.3fb-1 data sample collected by the D0 experiment in 2002-2006 during run II of the Fermilab Tevatron Collider. We measure the polarization parameter α=(σT-2σL)/(σT+2σL), where σT and σL are the transversely and longitudinally polarized components of the production cross section, as a function of the transverse momentum (pTΥ) for the Υ(1S) and Υ(2S). Significant pTΥ-dependent longitudinal polarization is observed for the Υ(1S). A comparison with theoretical models is presented. © 2008 The American Physical Society.Measurement of the polarization of the upsilon(1S) and upsilon(2S) states in pp collisions at square root[s]=1.96 TeV.
Phys Rev Lett 101:18 (2008) 182004
Abstract:
We present a study of the polarization of the Upsilon(1S) and Upsilon(2S) states using a 1.3 fb;{-1} data sample collected by the D0 experiment in 2002-2006 during run II of the Fermilab Tevatron Collider. We measure the polarization parameter alpha=(sigma_{T}-2sigma_{L})/(sigma_{T}+2sigma_{L}), where sigma_{T} and sigma_{L} are the transversely and longitudinally polarized components of the production cross section, as a function of the transverse momentum (p_{T};{Upsilon}) for the Upsilon(1S) and Upsilon(2S). Significant p_{T};{Upsilon}-dependent longitudinal polarization is observed for the Upsilon(1S). A comparison with theoretical models is presented.Search for t over(t, Ì„) resonances in the lepton plus jets final state in p over(p, Ì„) collisions at sqrt(s) = 1.96 TeV
Physics Letters Section B Nuclear Elementary Particle and High Energy Physics 668:2 (2008) 98-104
Abstract:
We present a search for a narrow-width heavy resonance decaying into top quark pairs (X → t over(t, ̄)) in p over(p, ̄) collisions at sqrt(s) = 1.96 TeV using approximately 0.9 fb-1 of data collected with the DØ detector at the Fermilab Tevatron Collider. This analysis considers t over(t, ̄) candidate events in the lepton plus jets channel with at least one identified b jet and uses the t over(t, ̄) invariant mass distribution to search for evidence of resonant production. We find no evidence for a narrow resonance X decaying to t over(t, ̄). Therefore, we set upper limits on σMeasurement of the differential cross section for the production of an isolated photon with associated jet in p over(p, ̄) collisions at sqrt(s) = 1.96  TeV
Physics Letters Section B Nuclear Elementary Particle and High Energy Physics 666:5 (2008) 435-445
Abstract:
The process p over(p, ̄) → γ + jet + X is studied using 1.0 fb-1 of data collected by the D0 detector at the Fermilab Tevatron p over(p, ̄) collider at a center-of-mass energy sqrt(s) = 1.96  TeV. Photons are reconstructed in the central rapidity region | yγ | < 1.0 with transverse momenta in the range 30 < pSearch for Higgs bosons decaying to tau pairs in pp over collisions with the D0 detector.
Phys Rev Lett 101:7 (2008) 071804