Light meson spectroscopy from Dalitz plot analyses ηc decays to η0K + K − , η0π + π − , and ηπ + π − produced in two-photon interactions

We study the processes γγ → ηc → η0KþK−, η0πþπ−, and ηπþπ− using a data sample of 519 fb−1 recorded with the BABAR detector operating at the SLAC PEP-II asymmetric-energy e+e− collider at center-of-mass energies at and near the Υ(nS) (n = 2, 3, 4) resonances. This is the first observation of the decay ηc → η0KþK− and we measure the branching fraction Γðηc → η0KþK−Þ=ðΓðηc → η0πþπ−Þ 1⁄4 0.644 0.039stat 0.032sys. Significant interference is observed between γγ → ηc → ηπþπ− and the nonresonant two-photon process γγ → ηπþπ−. A Dalitz plot analysis is performed of ηc decays to η0KþK−, η0πþπ−, and ηπþπ−. Combined with our previous analysis of ηc → KK ̄ π, we measure the K 0ð1430Þ parameters and the ratio between its η0K and πK couplings. The decay ηc → η0πþπ− is dominated by the f0ð2100Þ resonance, also observed in J=ψ radiative decays. A new a0(1700)→ ηπ resonance is observed in the ηc → ηπþπ− channel. We also compare ηc decays to η and η0 final states in association with scalar mesons as they relate to the identification of the scalar glueball

Search for the Lepton-Flavor-Violating Decays B-s(0) -> e(+/-)mu(-/+) and B-0 -> e(+/-)mu(-/+)

A search for the lepton-flavor-violating decays B0s\u2192e\ub1\u3bc 13 and B0\u2192e\ub1\u3bc 13 is performed with a data sample, corresponding to an integrated luminosity of 1.0\u2009\u2009fb 121 of pp collisions at s 1a=7\u2009\u2009TeV, collected by the LHCb experiment. The observed number of B0s\u2192e\ub1\u3bc 13 and B0\u2192e\ub1\u3bc 13 candidates is consistent with background expectations. Upper limits on the branching fractions of both decays are determined to be \u212c(B0s\u2192e\ub1\u3bc 13)<1.1(1.4) 710 128 and \u212c(B0\u2192e\ub1\u3bc 13)<2.8(3.7) 710 129 at 90% (95%) confidence level (C.L.). These limits are a factor of 20 lower than those set by previous experiments. Lower bounds on the Pati-Salam leptoquark masses are also calculated, MLQ(B0s\u2192e\ub1\u3bc 13)>101\u2009\u2009TeV/c2 and MLQ(B0\u2192e\ub1\u3bc 13)>126\u2009\u2009TeV/c2 at 95% C.L., and are a factor of 2 higher than the previous bounds

Search for the rare decays B→πl+l− and B0→ηl+l−

We present the results of a search for the rare flavor-changing neutral-current decays B→πl+l− (π=π±, π0 and l=e, μ) and B0→ηl+l− using a sample of e+e−→Υ(4S)→BB⎯⎯⎯ decays corresponding to 428 fb−1 of integrated luminosity collected by the BABAR detector. No significant signal is observed, and we set an upper limit on the isospin and lepton-flavor averaged branching fraction of B(B→πl+l−)&lt;5.9×10−8 and a lepton-flavor averaged upper limit of B(B0→ηl+l−)&lt;6.4×10−8, both at the 90% confidence level. We also report 90% confidence level branching fraction upper limits for the individual modes B+→π+e+e−, B0→π0e+e−, B+→π+μ+μ−, B0→π0μ+μ−, B0→ηe+e−, and B0→ημ+μ−