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51.
The high resolution proton magnetic resonance of selenophene has been studied at 100 Mc/s. The spectrum was analysed as an A2X2 system and the following coupling constants were obtained: J 23 = 5·35, J 24 = 1·05, J 34 = 3·56, J 25 = 2·47 c.p.s. Coupling was also observed between 77Se and the α and β protons and coupling constants of 48 c.p.s. (α) and 9·5 c.p.s. (β) were obtained. The τ values were 2·30 (α) and 2·88 (β). The results are compared with values available for furan, pyrrole and thiophene and the conclusion is drawn that selenophene is probably a planar molecule. 相似文献
52.
Daniel M. Heffernan 《Physics letters. A》1983,94(2):106-108
We show that for the Lasher-Basov model of a double contact injection laser the hysteresis in the light output as a function of the driving current in the gain region can be characterized by a single parameter. 相似文献
53.
Daniel M. Heffernan 《Physics letters. A》1984,103(5):286-288
The transient behaviour of degenerate four wave mixing (DFWM) in a three-level saturable absorber is analysed. We discuss two cases which are relevant to present day experiments. We obtain the transient reflectivity in the cases where the pump beams consist of (a) a single pulse and (b) a train of pulses. 相似文献
54.
Daniel M. Heffernan Richard L. Liboff 《International journal of quantum chemistry》1981,19(5):745-753
Exact wave functions and eigenenergy relations are obtained for a biwell potential as a function of interwell displacement and single well parameters. The proliferation of energies is shown explicitly as the wells are brought into close proximity. The model is compared with the opaque division-wall model. These results find important application in laser and nuclear physics. 相似文献
55.
Ishino H Abe K Abe K Adachi I Aihara H Anipko D Arinstein K Aushev T Bakich AM Barberio E Barbero M Bedny I Bitenc U Bizjak I Blyth S Bozek A Bracko M Browder TE Chang MC Chang P Chao Y Chen A Chen KF Chen WT Cheon BG Chistov R Choi Y Choi YK Cole S Dalseno J Dash M Drutskoy A Eidelman S Fratina S Gershon T Go A Gokhroo G Golob B Gorisek A Ha H Haba J Hara K Hayasaka K Hazumi M Heffernan D Hokuue T Hoshi Y Hou S Hsiung YB Iijima T Imoto A Inami K Ishikawa A Iwasaki Y Kang JH Kapusta P 《Physical review letters》2007,98(21):211801
We report a new measurement of the time-dependent CP-violating parameters in B(0)-->pi(+)pi(-) decays with 535 x 10(6) BB pairs collected with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider operating at the Upsilon(4S) resonance. We find 1464+/-65 B(0)-->pi(+)pi(-) events and measure the CP-violating parameters S(pipi)=-0.61+/-0.10(stat)+/-0.04(syst) and A(pipi)=+0.55+/-0.08(stat)+/-0.05(syst). We observe large direct CP violation with a significance greater than 5 standard deviations for any S(pipi) value. Using isospin relations, we measure the Cabibbo-Kobayashi-Maskawa quark-mixing matrix angle phi(2)=(97+/-11) degrees for the solution consistent with the standard model and exclude the range 11 degrees 相似文献
56.
Chang MC Abe K Abe K Adachi I Aihara H Anipko D Arinstein K Aushev T Bakich AM Barberio E Bay A Bedny I Belous K Bitenc U Bizjak I Blyth S Bondar A Bozek A Browder TE Chang P Chao Y Chen A Chen KF Chen WT Cheon BG Chistov R Choi SK Choi Y Choi YK Cole S Dalseno J Danilov M Dash M Drutskoy A Eidelman S Fratina S Gabyshev N Gershon T Go A Gokhroo G Ha H Haba J Hara T Hayasaka K Hazumi M Heffernan D Hokuue T Hoshi Y Hou S Hou WS Hsiung YB Iijima T Inami K Ishikawa A Ishino H Itoh R Iwasaki M 《Physical review letters》2007,98(13):131803
We report the first observation of B(0)-->J/psieta decay. These results are obtained from a data sample that contains 449 x10(6) BB[over] pairs accumulated at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. We observe a signal with a significance of 8.1 sigma and obtain a branching fraction of (9.5+/-1.7(stat)+/-0.8(syst)) x 10(-6). 相似文献
57.
Tajima O Hazumi M Adachi I Aihara H Aulchenko V Aushev T Bakich AM Barberio E Bay A Bedny I Bhardwaj V Bitenc U Bozek A Bracko M Browder TE Chang MC Chang P Chen A Chen KF Chen WT Cheon BG Chiang CC Chistov R Cho IS Choi Y Choi YK Dalseno J Danilov M Dash M Drutskoy A Eidelman S Epifanov D Go A Gokhroo G Golob B Haba J Hayasaka K Hayashii H Heffernan D Hokuue T Hoshi Y Hou WS Hsiung YB Hyun HJ Iijima T Ikado K Inami K Ishikawa A Ishino H Itoh R Iwasaki M Iwasaki Y Joshi NJ Kah DH Kaji H Kang JH 《Physical review letters》2007,99(21):211601
We report the first search for CP-violating decays of the Upsilon(4S) using a data sample that contains 535 x 10(6) Upsilon(4S) mesons with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. A partial reconstruction technique is employed to enhance the signal sensitivity. No significant signals were observed. We obtain an upper limit of 4 x 10(-7) at the 90% confidence level for the branching fractions of the CP violating modes, Upsilon(4S)-->B(0)B(0)-->J/psiK(S)(0)+J/psi(eta(c))K(S)(0). Extrapolating the result, we find that an observation with 5sigma significance is expected with a 30 ab(-1) data sample, which is within the reach of a future super B factory. 相似文献
58.
Chen KF Adachi I Aihara H Aulchenko V Aushev T Bahinipati S Bakich AM Balagura V Barberio E Bay A Belous K Bitenc U Bondar A Bozek A Bracko M Brodzicka J Browder TE Chang MC Chang P Chao Y Chen A Cheon BG Chiang CC Cho IS Choi Y Choi YK Cole S Danilov M Dash M Drutskoy A Eidelman S Fratina S Gabyshev N Golob B Ha H Haba J Hara T Hayasaka K Hazumi M Heffernan D Hokuue T Hoshi Y Hou WS Hsiung YB Hyun HJ Iijima T Ikado K Inami K Ishikawa A Ishino H Itoh R Iwasaki M Iwasaki Y Joshi NJ Kajiwara S 《Physical review letters》2007,99(22):221802
We present a search for the rare decays B --> h(*)nunu[over ], where h(*) stands for a light meson. A data sample of 535 x 10{6} BB[over ] pairs collected with the Belle detector at the KEKB e{+}e{-} collider is used. Signal candidates are required to have an accompanying B meson fully reconstructed in a hadronic mode and signal side particles consistent with a single h(*) meson. No significant signal is observed and we set upper limits on the branching fractions at 90% confidence level. The limits on B{0} --> K{*0}nunu[over ] and B{+} --> K{+}nunu[over ] decays are more stringent than the previous constraints, while the first searches for B{0} --> K{0}nunu[over ], pi{0}nunu[over ], rho{0}nunu[over ], varphinunu[over ] and B{+} --> K{*+}nunu[over ], rho{+}nunu[over ] are reported. 相似文献
59.
Kusaka A Wang CC Ishino H Abe K Abe K Adachi I Aihara H Anipko D Aulchenko V Aushev T Bakich AM Barberio E Bay A Bedny I Belous K Bitenc U Bizjak I Blyth S Bondar A Bozek A Bracko M Browder TE Chang MC Chang P Chao Y Chen A Chen KF Chen WT Cheon BG Chistov R Choi SK Choi Y Choi YK Cole S Dalseno J Danilov M Dash M Dragic J Drutskoy A Eidelman S Fratina S Fujikawa M Gabyshev N Garmash A Gershon T Gokhroo G Golob B Ha H Haba J Hara T Hastings NC Hayasaka K Hayashii H Hazumi M Heffernan D Hokuue T 《Physical review letters》2007,98(22):221602
We present a measurement of CP asymmetry using a time-dependent Dalitz plot analysis of B0-->pi+pi-pi0 decays based on a 414 fb(-1) data sample containing 449 x 10(6) BB pairs. The data was collected on the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric energy e+ e- collider. Combining our analysis with information on charged B decay modes, we perform a full Dalitz and isospin analysis and obtain a constraint on the CKM angle phi2, 68 degrees < phi2 < 95 degrees as the 68.3% confidence interval for the phi2 solution consistent with the standard model (SM). A large SM-disfavored region also remains. 相似文献
60.
An enantioselective, convergent, total synthesis of the antiviral marine natural product (-)-hennoxazole A has been completed in 17 steps, longest linear sequence, from serine methyl ester and in 9 steps from an achiral bisoxazole intermediate. Elaboration of a thiazolidinethione allowed for rapid assembly of the pyran-based ring system. Key late-stage coupling was effected by deprotonation of the bisoxazole methyl group, followed by alkylation with an allylic bromide side chain segment. [structure: see text] 相似文献