22-28 July 2010
Palais des Congrès de Paris
Europe/Paris timezone

Studies of Upsilon Decays at Belle

23 Jul 2010, 17:05
18m
Salle 253 ()

Salle 253

Parallel Session Talk 04 - Hadronic Structure, Parton Distributions, soft QCD, Spectroscopy 04 - Hadronic Structure, Parton Distributions, soft QCD, Spectroscopy

Speaker

Mauro Verzetti (INFN Torino)

Description

* Measurement of Upsilon(5S) decays to B0 and B+ mesons Decays of the Upsilon(5S) resonance to channels with B+ and B0 mesons are studied using a 23.6 fb^-1 data sample collected with the Belle detector at the KEKB asymmetric-energy e+e- collider. Fully reconstructed B+ -> J/psi K+, B0 -> J/psi K*0, B+ -> Dbar0 pi+ and B0 -> D- pi+ decays are used to obtain the charged and neutral Bproduction rates per b-bbar event, f(B+) = (72.1 ^(+3.9)_(-3.8) +/- 5.0)% and f(B0) = (77.0 ^+(5.8)_(-5.6) +/-6.1)%. Assuming equal rates to B+ and B0 mesons in all channels produced at the Upsilon(5S) energy, we measure the fractions for transitions to two-body and three-body channels with B meson pairs, f(B-Bbar) = (5.5^(+1.0)_(-0.9)+/- 0.4)%, f(B Bbar*+B*Bbar) = (13.7 +/- 1.3 +/- 1.1)%, f(B* Bbar*) = (37.5^(+2.1)_(-1.9) +/- 3.0)%, f(B Bbar pi) = (0.0 +/- 1.2 +/- 0.3)%, f(BBbar* pi+B* Bbar pi) = (7.3^(+2.3)_(-2.1) +/- 0.8)%, and f(B* Bbar* pi) = (1.0^(+1.4)_(-1.3) +/- 0.4)%. The latter three fractions are obtained assuming isospin conservation. *Observation of an enhancement in e+e- -> Upsilon(1S) pi+ pi-, Upsilon(2S) pi+ pi-, and Upsilon(3S) pi+ pi- production around sqrt(s)=10.89 GeV at Belle We measure the production cross sections for e+e- -> Upsilon(1S) pi+ pi-, Upsilon(2S) pi+ pi-, and Upsilon(3S) pi+ pi- as a function of sqrt(s) between 10.83 GeV and 11.02 GeV. The data consists of 8.1 fb^-1 collected with the Belle detector at the KEKB e+e- collider. We observe enhanced production in all three final states that does not conform well with the conventional Upsilon(10860) lineshape. * Search for Upsilon(2S) -> eta_b gamma and Upsilon(2S) -> eta Upsilon The Belle experiment has integrated a record sample of 160M Upsilon(2S) decays on the resonant peak. First results of searches for rare radiative transitions (Upsilon(2S) -> eta_b(1S) gamma and chi_b0(1P) -> Upsilon(1S) gamma), and the hadronic transition Upsilon(2S) -> eta Upsilon will be presented.

Primary author

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