Limits on quark-lepton compositeness scales from dileptons produced in 1.8 TeV pp-collisions
Physical Review Letters 79:12 (1997) 2198-2203
Abstract:
The dilepton mass spectrum in pp-→|+|-+X interactions is studied using dielectrons (ee) and dimuons (μμ) in 100 pb- of data collected with the Collider Detector at Fermilab. The data are consistent with standard model predictions. The mass spectrum, being a probe for new physics, is examined for new interactions of quarks and leptons from a common composite structure. Assuming a contact interaction with the conventional coupling g20/4π = 1, limits on chiral quark-electron and quark-muon compositeness scales in the range of 2.5 to 4.2 TeV are obtained. © 1997 The American Physical Society.Measurement of Diffractive Dijet Production at the Fermilab Tevatron
Physical Review Letters 79:14 (1997) 2636-2641
Abstract:
We report the observation and measurement of the rate of diffractive dijet production at the Fermilab Tevatron p¯p collider at √s=1.8TeV. In events with two jets of ET>20GeV, 1.8<|η|<3.5, and η1η2>0, we find that the diffractive to nondiffractive production ratio is RJJ=[0.75±0.05(stat)±0.09(syst)]%. By comparing this result, in combination with our measured rate for diffractive W boson production reported previously, with predictions based on a hard partonic pomeron structure, we determine the pomeron gluon fraction to be fg=0.7±0.2. © 1997 American Physical Society.Measurement of the B¯→D±ô±¹Â¯ partial width and form factor parameters
Physical Review Letters 79:12 (1997) 2208-2212
Abstract:
We have studied the decayB¯→Dlν¯ where l = e or μ. From a fit to the differential decay ratedγ/dwwe measure the rate normalizationFD(1) |V cb | and form factor slopeÏ�ˆ2D, and, using measured values ofÏ„B, findγ(B¯→D±ô±¹Â¯) = (12.0 ± 0.9 ± 2.1) ns−1 . The resulting branching fractions areB (B¯0 → D+ l−ν¯) = (1.87 ± 0.15 ± 0.32)% and B (B− → D0l−ν¯) = (1.94 ± 0.15 ± 0.34)% . The form factor parameters are in agreement with those measured in B¯ → D*l−ν¯ decays, as predicted by heavy quark effective theory. © 1997 The American Physical Society.Measurement of the direct photon spectrum in [Formula presented] decays
Physical Review D - Particles, Fields, Gravitation and Cosmology 55:9 (1997) 5273-5281
Abstract:
Using data taken with the CLEO II detector at the Cornell Electron Storage Ring, we have determined the ratio of branching fractions: [Formula presented]. From this ratio, we have determined the QCD scale parameter [Formula presented] (defined in the modified minimal subtraction scheme) to be [Formula presented] MeV, from which we determine a value for the strong coupling constant [Formula presented], or [Formula presented]. © 1997 The American Physical Society.New upper limit on the decay [Formula presented]
Physical Review D Particles Fields Gravitation and Cosmology 56:9 (1997) 5359-5365