Guy Wilkinson

Abstract:

Using a large sample (≈11800 events) of D+→K -π+e+νe and D+→K -π+μ+νμ decays collected by the CLEO-c detector running at the ψ(3770), we measure the helicity basis form factors free from the assumptions of spectroscopic pole dominance and provide new, accurate measurements of the absolute branching fractions for D +→K̄*0e+νe and D+→K̄*0μ+νμ decays. We find branching fractions which are consistent with previous world averages. Our measured helicity basis form factors are consistent with the spectroscopic pole dominance predictions for the three main helicity basis form factors describing D+→K̄*0 +ν decay. The ability to analyze D+→K -π+μ+νμ allows us to make the first nonparametric measurements of the mass-suppressed form factor. Our result is inconsistent with existing lattice QCD calculations. Finally, we measure the form factor that controls nonresonant s-wave interference with the D +→K̄*0+ν amplitude and search for evidence of possible additional nonresonant d- or f-wave interference with the K̄*0. © 2010 The American Physical Society.

Abstract:

A search for J/ψ radiative decay to weakly interacting neutral final states was performed using the CLEO-c detector at the Cornell Electron Storage Ring. J/ψ events were selected by observing the hadronic decay ψ(2S)→π+π-J/ψ. A total of 3.7×106 J/ψ events were used to study the decay J/ψ→γ+X, where X is a narrow state that is invisible to the detector. No significant signal was observed, and upper limits on the branching fraction were set for masses mX up to 960MeV/c2. The upper limit corresponding to mX=0 is 4.3×10-6 at the 90% confidence level. © 2010 The American Physical Society.