27 research outputs found
Evidence of and search for double-charmonium production in and decays
Using data samples of and
events collected with the Belle detector, a first experimental
search has been made for double-charmonium production in the exclusive decays
, where , , , , and . No significant signal is
observed in the spectra of the mass recoiling against the reconstructed
or except for the evidence of production with a
significance of for . The
measured branching fraction \BR(\Upsilon(1S)\rightarrow J/\psi+\chi_{c1}) is
. The
confidence level upper limits on the branching fractions of the other modes
having a significance of less than are determined. These results are
consistent with theoretical calculations using the nonrelativistic QCD
factorization approach.Comment: 12 pages, 4 figures, 1 table. The fit range was extended to include
X(4160) signal according to referee's suggestions. Other results unchanged.
Paper was accepted for publication as a regular article in Physical Review
Measurement of the Proton Structure Function F[2] at HERA
報告番号: 甲10834 ; 学位授与年月日: 1994-10-24 ; 学位の種別: 課程博士 ; 学位の種類: 博士(理学) ; 学位記番号: 博理第2835号 ; 研究科・専攻: 理学系研究科物理学専
Radiative and Electroweak Penguin Decays of B Mesons
The huge datasets collected at the two B factories, Belle and BaBar, have made it possible to explore precisely the radiative penguin process b --> s gamma, and to study the electroweak penguin process b --> s l+ l- and the suppressed radiative process b --> d gamma in detail, all in exclusive channels and inclusive measurements. Theoretical tools have also advanced to meet or surpass the experimental precision especially in inclusive calculations and various ratios of exclusive channels. In this article, we review the theoretical and experimental progress in the radiative and electroweak penguin decays of B mesons in the past decade