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Abstract:

The role of charm in testing the Standard Model description of quark mixing and CP violation through measurements of lifetimes, decay constants and semileptonic form factors is reviewed. Together with Lattice QCD, charm has the potential this decade to maximize the sensitivity of the entire flavor physics program to new physics. and pave the way for understanding physics beyond the Standard Model at the LHC in the coming decade. The status of indirect searches for physics beyond the Standard Model through charm mixing, CP-violation and rare decays is also reported.

Abstract:

We present results of a search for anomalous production of events containing a charged lepton (l, either e or μ) and a photon (γ), both with high transverse momentum, accompanied by additional signatures X, including missing transverse energy (ET) and additional leptons and photons. We use the same selection criteria as in a previous CDF search but with a substantially larger data set, 305 pb-1, a pp̄ collision energy of 1.96 TeV, and the CDF II detector. We find 42lγET events versus an expectation of 37.3±5.4 events. We observe 31 γ+X events versus an expectation of 23.0±2.7 events. We find no events similar to the run eeγγET event. © 2006 The American Physical Society.

Abstract:

We present results of a search for anomalous production of events containing a charged lepton (l, either e or mu) and a photon (gamma), both with high transverse momentum, accompanied by additional signatures X, including missing transverse energy (ET) and additional leptons and photons. We use the same selection criteria as in a previous CDF search but with a substantially larger data set, 305 pb(-1), a pp collision energy of 1.96 TeV, and the CDF II detector. We find 42 lgammaET events versus an expectation of 37.3+/-5.4 events. We observe 31 llgamma+X events versus an expectation of 23.0+/-2.7 events. We find no events similar to the run I eegammagammaET event.

Abstract:

Using data taken with the CLEO III detector at the Cornell Electron Storage Ring, we have investigated the direct photon spectrum in the decays Υ(1S)→γgg, Υ(2S)→γgg, Υ(3S)→γgg. The latter two of these are first measurements. Our analysis procedures differ from previous ones in the following ways: (a) background estimates (primarily from π0 decays) are based on isospin symmetry rather than a determination of the π0 spectrum, which permits measurement of the Υ(2S) and Υ(3S) direct photon spectra without explicit corrections for π0 backgrounds from, e.g., χbJ states, (b) we estimate the branching fractions with a parametrized functional form (exponential) used for the background, and c) we use the high-statistics sample of Υ(2S)→ππΥ(1S) to obtain a tagged sample of Υ(1S)→γ+X events, for which there are no QED backgrounds. We determine values for the ratio of the inclusive direct photon decay rate to that of the dominant three-gluon decay Υ→ggg(Rγ= B(ggγ)/B(ggg)) to be Rγ(1S)=(2.70±0.01±0.13±0. 24)%, Rγ(2S)=(3.18±0.04±0.22±0.41)%, and Rγ(3S)=(2.72±0.06±0.32±0.37)%, where the errors shown are statistical, systematic, and theoretical model dependent, respectively. Given a value of Q2, one can estimate a value for the strong coupling constant αs(Q2) from Rγ. © 2006 The American Physical Society.