Search for the decay τ-→3π-2π+2π0ντ
Physical Review D Particles Fields Gravitation and Cosmology 73:11 (2006)
Abstract:
A search for the decay of the τ lepton to five charged and two neutral pions is performed using data collected by the BABAR detector at the PEP-II asymmetric-energy e+e- collider. The analysis uses 232fb-1 of data at center-of-mass energies on or near the Υ(4S) resonance. We observe 10 events with an expected background of 6.5-1.4+2.0 events. In the absence of a signal, we set the limit on the branching ratio B(τ-→3π- 2π+2π0ντ)<3.4×10-6 at the 90% confidence level. This is a significant improvement over the previously established limit. In addition, we search for the decay mode τ-→2ωπ-ντ. We observe 1 event with an expected background of 0.4+1.0-0.4 events and calculate the upper limit B(τ-→2ωπ-ντ)<5.4×10-7 at the 90% confidence level. This is the first upper limit for this mode. © 2006 The American Physical Society.Search for the decay B+→τ+ντ
Physical Review D Particles Fields Gravitation and Cosmology 73:5 (2006)
Abstract:
We search for the rare leptonic decay B+→τ+ντ in a sample of 232×106 BB̄ pairs collected with the BABAR detector at the SLAC PEP-II B-Factory. Signal events are selected by examining the properties of the B meson recoiling against the semileptonic decay B-→D*0-ν̄. We find no evidence for a signal and set an upper limit on the branching fraction of B(B+→τ+ντ)<2.8×10-4 at the 90% confidence level. We combine this result with a previous, statistically independent BABAR search for B+→τ+ντ to give an upper limit of B(B+→τ+ντ)<2.6×10-4 at the 90% confidence level. © 2006 The American Physical Society.Study of the X(3872) and Y(4260) in B0→J/ψπ+π-K0 and B-→J/ψπ+π-K- decays
Physical Review D Particles Fields Gravitation and Cosmology 73:1 (2006)
Abstract:
We present results of a search for the X(3872) in B0→X(3872)KS0, X(3872)→J/ψπ+π-, improved measurements of B-→X(3872)K-, and a study of the J/ψπ+π- mass region above the X(3872). We use 232×106 BB̄ pairs collected at the Υ(4S) resonance with the BABAR detector at the PEP-II e+e- asymmetric-energy storage rings. The results include the 90% confidence interval 1.34×10-6Study of the decay B̄0→D*+ωπ-
Physical Review D Particles Fields Gravitation and Cosmology 74:1 (2006)
Abstract:
We report on a study of the decay B̄0→D*+ωπ- with the BABAR detector at the PEP-II B-factory at the Stanford Linear Accelerator Center. Based on a sample of 232×106 BB̄ decays, we measure the branching fraction B(B̄0→D*+ωπ-)=(2.88±0. 21(stat.)±0.31(syst.))×10-3. We study the invariant mass spectrum of the ωπ- system in this decay. This spectrum is in good agreement with expectations based on factorization and the measured spectrum in τ-→ωπ-ντ. We also measure the polarization of the D*+ as a function of the ωπ- mass. In the mass region 1.1 to 1.9 GeV we measure the fraction of longitudinal polarization of the D*+ to be ΓL/Γ=0.654±0.042(stat.)±0.016(syst.). This is in agreement with the expectations from heavy-quark effective theory and factorization assuming that the decay proceeds as B̄0→ D*+ρ(1450)-, ρ(1450)-→ωπ-. © 2006 The American Physical Society.The e+e-→3(π+π-), 2(π+π-π0) and K+K-2(π+π-) cross sections at center-of-mass energies from production threshold to 4.5 GeV measured with initial-state radiation
Physical Review D Particles Fields Gravitation and Cosmology 73:5 (2006)