Mu3e

Abstract:

We report on a search for Bs0→μ+μ- and B0→μ+μ- decays using proton-antiproton collision data at √s=1.96 TeV corresponding to 10 fb-1 of integrated luminosity collected by the CDF II detector at the Fermilab Tevatron collider. The observed number of B0 candidates is consistent with background-only expectations and yields an upper limit on the branching fraction of B(B0→μ+μ-)<4.6×10-9 at 95% confidence level. We observe an excess of Bs0 candidates. The probability that the background processes alone could produce such an excess or larger is 0.94%. The probability that the combination of background and the expected standard model rate of Bs0→μ+μ- could produce such an excess or larger is 6.8%. These data are used to determine a branching fraction B(Bs0→μ+μ-)=(1.3-0.7+0.9) ×10-8 and provide an upper limit of B(Bs0→μ +μ-)<3.1×10-8 at 95% confidence level. © 2013 American Physical Society.

Abstract:

The beauty to up quark coupling constant |Vub| can be extracted from B→ρe+νe combined with the form factors for D→K*e+νe and B→Vℓ+ℓ- and D→ρe+ν e. Using the entire CLEO-c ψ(3770)→DD̄ event sample, corresponding to an integrated luminosity of 818 pb-1 and approximately 5.4×106 DD̄ events, we measure the form factors for the decays D0→ρ-e+νe and D +→ρ0e+νe for the first time and the branching fractions with improved precision. A four-dimensional unbinned maximum likelihood fit determines the form factor ratios to be V(0)/A 1(0)=1.48±0.15±0.05 and A2(0)/A 1(0)=0.83±0.11±0.04. Assuming Cabibbo-Kobayashi-Maskawa unitarity, the known D meson lifetimes, and our measured branching fractions we obtain the form factor normalizations A1(0), A2(0), and V(0). We also present a measurement of the branching fraction for D +→ωe+νe with improved precision. © 2013 American Physical Society.

Abstract:

Results are reported of a search for a deviation in the jet production cross section from the prediction of perturbative quantum chromodynamics at next-to-leading order. The search is conducted using a 7 TeV proton-proton data sample corresponding to an integrated luminosity of 5.0 fb-1, collected with the Compact Muon Solenoid detector at the Large Hadron Collider. A deviation could arise from interactions characterized by a mass scale Λ too high to be probed directly at the LHC. Such phenomena can be modeled as contact interactions. No evidence of a deviation is found. Using the CL s criterion, lower limits are set on Λ of 9.9 TeV and 14.3 TeV at 95% confidence level for models with destructive and constructive interference, respectively. Limits obtained with a Bayesian method are also reported. © 2013 CERN.