Search for first-generation scalar and vector leptoquarks
Physical Review D Particles Fields Gravitation and Cosmology 64:9 (2001)
Abstract:
We describe a search for the pair production of first-generation scalar and vector leptoquarks in the [Formula Presented] and [Formula Presented] channels by the DØ Collaboration. The data are from the 1992–1996 [Formula Presented] run at [Formula Presented] at the Fermilab Tevatron collider. We find no evidence for leptoquark production; in addition, no kinematically interesting events are observed using relaxed selection criteria. The results from the [Formula Presented] and [Formula Presented] channels are combined with those from a previous DØ analysis of the [Formula Presented] channel to obtain 95% confidence level (C.L.) upper limits on the leptoquark pair-production cross section as a function of mass and of [Formula Presented] the branching fraction to a charged lepton. These limits are compared to next-to-leading-order theory to set 95% C.L. lower limits on the mass of a first-generation scalar leptoquark of 225, 204, and 79 [Formula Presented] for [Formula Presented] [Formula Presented] and 0, respectively. For vector leptoquarks with gauge (Yang-Mills) couplings, 95% C.L. lower limits of 345, 337, and 206 [Formula Presented] are set on the mass for [Formula Presented] [Formula Presented] and 0, respectively. Mass limits for vector leptoquarks are also set for anomalous vector couplings. © 2001 The American Physical Society.Search for resonance decays to a v̄ plus jet in e+p scattering at des y HERA
Physical Review D 63:5 (2001)
Abstract:
A study of the v̄-jet mass spectrum in e+p→v̄X events at a center-of-mass energy 300 GeV has been performed with the ZEUS detector at the HERA collider at DESY using an integrated luminosity of 47.7 pb-1. The mass spectrum is in good agreement with that expected from standard model processes over the v̄-jet mass range studied. No significant excess attributable to the decay of a narrow resonance is observed. By using both e+p→>e+X and e+p-vX data, mass-dependent limits are set on the s-channel production of scalar and vector resonant states. Couplings to first-generation quarks are considered and limits are presented as a function of the e+q and v̄q branching ratios. These limits are used to constrain the production of leptoquarks and A-parity violating squarks. © 2001 The American Physical Society.Differential cross section for w boson production as a function of transverse momentum in p(p)over-bar collisions at √s=1.8 TeV
PHYSICS LETTERS B 513:3-4 (2001) 292-300
High-pT jets in p(p)over-bar collisions at √s=630 and 1800 GeV - art. no. 032003
PHYSICAL REVIEW D 64:3 (2001) ARTN 032003
Inclusive jet production in p(p)over-bar collisions
PHYSICAL REVIEW LETTERS 86:9 (2001) 1707-1712