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排序方式: 共有275条查询结果,搜索用时 15 毫秒
91.
Lee YJ Wang MZ Abe K Abe K Abe T Aihara H Asano Y Aulchenko V Aushev T Aziz T Bahinipati S Bakich AM Ban Y Bedny I Bitenc U Bizjak I Bondar A Bozek A Bracko M Brodzicka J Browder TE Chang P Chao Y Cheon BG Chistov R Choi SK Choi Y Chuvikov A Danilov M Dash M Dong LY Drutskoy A Eidelman S Eiges V Fratina S Gabyshev N Garmash A Gershon T Gokhroo G Golob B Guo R Haba J Hayasaka K Hayashii H Hazumi M Higuchi T Hinz L Hokuue T Hoshi Y Hou WS Hsiung YB Imoto A Inami K Ishikawa A Itoh R Iwasaki H 《Physical review letters》2004,93(21):211801
We report the first observation of the charmless hyperonic B decay, B+-->LambdaLambdaK+, using a 140 fb(-1) data sample recorded at the Upsilon(4S) resonance with the Belle detector at the KEKB (e+)(e-) collider. The measured branching fraction is B(B+-->LambdaLambdaK+) = (2.91(+0.90)(-0.70) +/- 0.38) x 10(-6). We also perform a search for the related decay mode B+-->LambdaLambdapi+, but do not find a significant signal. We set a 90% confidence-level upper limit of B(B+-->LambdaLambdapi+) < 2.8 x 10(-6). 相似文献
92.
Schwanda C Abe K Abe K Abe T Adachi I Aihara H Akatsu M Asano Y Aushev T Bahinipati S Bakich AM Ban Y Banas E Bay A Bizjak I Bondar A Bozek A Bracko M Browder TE Chang MC Chao Y Cheon BG Choi Y Choi YK Chuvikov A Cole S Danilov M Dash M Dong LY Drutskoy A Eidelman S Eiges V Gabyshev N Gershon T Gokhroo G Golob B Hazumi M Higuchi I Hinz L Hokuue T Hoshi Y Hou WS Huang HC Iijima T Inami K Ishikawa A Itoh R Iwasaki H Iwasaki M Kang JH Kang JS Kapusta P Katayama N Kawai H Kichimi H Kim HJ 《Physical review letters》2004,93(13):131803
We have searched for the decay B+-->omegal(+)nu (l=e or mu) in 78 fb(-1) of Upsilon(4S) data (85x10(6)BB events) accumulated with the Belle detector. The final state is fully reconstructed using the omega decay into pi(+)pi(-)pi(0), combined with detector hermeticity to estimate the neutrino momentum. A signal of 414+/-125 events is found in the data, corresponding to a branching fraction of (1.3+/-0.4+/-0.2+/-0.3)x10(-4), where the first two errors are statistical and systematic, respectively. The third error reflects the estimated form-factor uncertainty. 相似文献
93.
Dragic J Gershon T Abe K Abe K Abe T Aihara H Asano Y Aulchenko V Aushev T Aziz T Bakich AM Banas E Bay A Bedny I Bitenc U Bizjak I Blyth S Bondar A Bozek A Bracko M Browder TE Chang P Chao Y Cheon BG Chistov R Choi SK Choi Y Chuvikov A Cole S Dong LY Dowd R Eidelman S Eiges V Enari Y Epifanov D Fratina S Gabyshev N Gokhroo G Golob B Gordon A Haba J Hastings NC Hayashii H Hazumi M Higuchi T Hinz L Hokuue T Hoshi Y Hou WS Hsiung YB Iijima T Inami K Ishikawa A Itoh R Iwasaki H Iwasaki M Kang JH 《Physical review letters》2004,93(13):131802
We present the first evidence of the decay B0-->rho(0)pi(0), using 140 fb(-1) of data collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric e(+)e(-) collider. We detect 15.1+/-4.8 signal events with a significance of 3.5 standard deviations and measure the branching fraction to be B(B0-->rho(0)pi(0))=(5.1+/-1.6(stat)+/-0.9(syst))x10(-6). 相似文献
94.
Enari Y Abe K Abe K Abe T Adachi I Aihara H Asano Y Aso T Aulchenko V Aushev T Bakich AM Ban Y Bedny I Bizjak I Bondar A Bozek A Bracko M Browder TE Chao Y Cheon BG Choi SK Choi Y Choi YK Chuvikov A Danilov M Dong LY Eidelman S Eiges V Epifanov D Fukunaga C Gabyshev N Garmash A Gershon T Gokhroo G Golob B Handa F Hara T Hayasaka K Hayashii H Hazumi M Hokuue T Hoshi Y Hou WS Huang HC Iijima T Inami K Ishikawa A Itoh R Iwasaki H Iwasaki M Iwasaki Y Kang JH Kang JS Kataoka SU Katayama N Kawai H 《Physical review letters》2004,93(8):081803
We have searched for the lepton flavor violating decay tau(-)-->micro(-)eta using a data sample of 84.3 fb(-1) accumulated with the Belle detector at KEK. The eta meson was detected through the decay modes: eta-->gammagamma and pi(+)pi(-)pi(0). No signal candidates are found, and we obtain an upper limit for the branching fraction B(tau(-)-->micro(-)eta)<3.4 x 10(-7) at the 90% confidence level. 相似文献
95.
Koppenburg P Abe K Abe K Abe T Adachi I Aihara H Akatsu M Asano Y Aulchenko V Aushev T Bakich AM Ban Y Bay A Bitenc U Bizjak I Bondar A Bozek A Bracko M Browder TE Chang P Chao Y Chen KF Cheon BG Choi Y Chuvikov A Cole S Danilov M Dash M Dong LY Drutskoy A Eidelman S Eiges V Enari Y Fang F Fratina S Gabyshev N Garmash A Gershon T Gokhroo G Golob B Haba J Hayashii H Hazumi M Higuchi T Hinz L Hokuue T Hoshi Y Hou WS Hsiung YB Iijima T Inami K Ishikawa A Itoh R Iwasaki H Iwasaki M Kang JH Kang JS 《Physical review letters》2004,93(6):061803
We report a fully inclusive measurement of the flavor changing neutral current decay b --> sgamma in the energy range 1.8 GeV < or = E*gamma < or = 2.8 GeV, covering 95% of the total spectrum. Using 140 fb(-1), we obtain B(b --> sgamma) = (3.55+/-0.32(+0.30+0.11)(-0.31-0.07)) x 10(-4), where the errors are statistical, systematic, and from theory corrections. We also measure the first and second moments of the photon energy spectrum above 1.8 GeV and obtain (Egamma) = 2.292+/-0.026+/-0.034 GeV and (E2gamma) - (Egamma)2 = 0.0305+/-0.0074+/-0.0063 GeV2, where the errors are statistical and systematic. 相似文献
96.
Abe K Abe K Abe R Abe T Ahn BS Aihara H Akatsu M Asano Y Aso T Aulchenko V Aushev T Bakich AM Ban Y Banas E Bay A Bedny I Behera PK Bondar A Bozek A Bracko M Brodzicka J Browder TE Casey BC Chang P Chao Y Cheon BG Chistov R Choi SK Choi Y Danilov M Dong LY Dragic J Drutskoy A Eidelman S Eiges V Enari Y Fang F Fukunaga C Gabyshev N Garmash A Gershon T Gordon A Guo R Handa F Hara T Harada Y Hastings NC Hayashii H Hazumi M Heenan EM Higuchi I Higuchi T Hojo T Hokune T Hoshi Y Hoshina K Hou SR 《Physical review letters》2002,89(15):151802
The B meson decay modes B-->Dpp; and B-->D(*)pp; have been studied using 29.4 fb(-1) of data collected with the Belle detector at KEKB. The B;(0)-->D(0)pp; and B;(0)-->D(*0)pp; decays have been observed for the first time with branching fractions B(B;(0)-->D(0)pp;)=(1.18+/-0.15+/-0.16)x10(-4) and B(B;(0)-->D(*0)pp;)=(1.20(+0.33)(-0.29)+/-0.21)x10(-4). No signal has been found for the B+-->D(+)pp; and B+-->D(*+)pp; decay modes, and the corresponding upper limits at 90% C.L. are presented. 相似文献
97.
Abe K Abe K Abe R Abe T Adachi I Ahn BS Aihara H Akatsu M Asano Y Aso T Aushev T Bakich AM Ban Y Banas E Behari S Behera PK Bondar A Bozek A Brodzicka J Browder TE Casey BC Chang P Chao Y Cheon BG Chistov R Choi SK Choi Y Dong LY Dragic J Drutskoy A Eidelman S Eiges V Enari Y Everton CW Fang F Fujii H Fukunaga C Fukushima M Gabyshev N Garmash A Gershon T Gordon A Guler H Guo R Haba J Hamasaki H Hanagaki K Handa F Hara K Hara T Hastings NC Hayashii H Hazumi M Heenan EM Higuchi I Higuchi T 《Physical review letters》2002,88(17):171801
The lifetimes of the B(0) and B- mesons are extracted from 29.1 fb(-1) of data collected with the Belle detector at the KEK B factory. A fit to the decay length differences of neutral and charged B meson pairs, measured in events where one of the B mesons is fully reconstructed in several hadronic modes, yields tau(B(0)) = 1.554+/-0.030(stat)+/-0.019(syst) ps, tau(B-) = 1.695+/-0.026(stat)+/-0.015(syst) ps, and tau(B-)/tau(B(0)) = 1.091+/-0.023(stat)+/-0.014(syst). 相似文献
98.
Abe K Abe K Abe T Adachi I Aihara H Akatsu M Asano Y Aso T Aulchenko V Aushev T Bakich AM Ban Y Banas E Behari S Behera PK Bondar A Bozek A Bracko M Browder TE Casey BC Chang P Chao Y Cheon BG Chistov R Choi SK Choi Y Dong LY Dragic J Drutskoy A Eidelman S Eiges V Everton CW Fang F Fujii H Fukunaga C Fukushima M Gabyshev N Garmash A Gershon T Golob B Gordon A Gotow K Guo R Haba J Hamasaki H Hanagaki K Handa F Hara K Hara T Hastings NC Hayashii H Hazumi M Heenan EM Higuchi I Higuchi T Hojo T 《Physical review letters》2002,89(1):011803
We report the first observation of chi(c2) production in B meson decays. We find an inclusive B-->chi(c2)X branching fraction of (1.80(+0.23)(-0.28)+/-0.26) x 10(-3). The data set, collected with the Belle detector at the KEKB e(+)e(-) collider, consists of 31.9 x 10(6) BB events. We also present branching fractions and momentum spectra for both chi(c1) and chi(c2) production. 相似文献
99.
Under the right conditions, bromine trifluoride can be a useful tool for generating new types of reactions and compounds. Thus, tris(methylthio)alkyl derivatives, easily prepared from the corresponding alkyl bromides, were converted to the corresponding RCHBrCF2SMe or RCHBrCF3 compounds. The bromine atom, however, could be easily reduced forming eventually R'CF2SMe or R'CF3. If desired, the bromine atom can serve as an entry for constructing terminal difluoroolefins. 相似文献
100.