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91.
A relatively simple and convenient procedure for the determination of small amounts of fluoride has been established. It is based on the decrease in absorbance when fluoride is added to a solution of the zirconium—Chrome Azurol S complex. Microgram amounts of fluoride can be determined with an error of better than about 2%. Some practical applications are presented. 相似文献
92.
Photo-excited arenes have been found to initiate a substitution reaction in which the sulfonyloxy group of α-sulfonyloxyketones is displaced, and the corresponding β-arylketones are formed. Evidence is presented that the electronically excited arene need not be involved directly in the substitution step. It would seem to be more likely that upon interaction with the sulfonyloxyketone a reactive species derived from the latter is produced which is capable of aromatic substitution. 相似文献
93.
To examine wall effects, the steady state settling velocities of single solid spheres of various diameters were measured in triangular and square cylinders, and between parallel plates, which were filled up with highly viscous aqueous milet jelley solutions. The wall effect for the steady state motion of single spheres in a narrow space has to date been correlated by the wall correction factor. The wall correction factors of single solid spheres were correlated in such apparatus in the creeping flow region. 相似文献
94.
Majumder G Abe K Abe K Adachi I Aihara H Asano Y Aulchenko V Aushev T Bahinipati S Bakich AM Banerjee S Bedny I Bitenc U Bizjak I Blyth S Bondar A Bozek A Bracko M Brodzicka J Browder TE Chang MC Chang P Chao Y Chen A Chen KF Chen WT Cheon BG Chistov R Choi Y Chuvikov A Cole S Dalseno J Danilov M Dash M Drutskoy A Eidelman S Enari Y Fratina S Gabyshev N Gershon T Go A Gokhroo G Golob B Gorisek A Haba J Hara T Hastings NC Hayasaka K Hayashii H Hazumi M Hinz L Hokuue T Hoshi Y Hou S Hou WS 《Physical review letters》2005,95(4):041803
We report evidence for B(0) --> D(0)D(-) and the first observation of the decay modes B(-) --> D(0)D(-) and B(-) --> D(0)D(*-) based on a sample of 152 x 10(6) BB events collected by the Belle detector at KEKB. The branching fractions for B(0) --> D(+) D(-), B--->D(0)D(-), and B--> D(0)D(*-) are found to be (1.91 +/- 0.51 +/- 0.30) x10(-4), (4.83 +/- 0.78 +/- 0.58) x 10(-4), and (4.57 +/- 0.71 +/- 0.56) x 10(-4), respectively. Charge asymmetries in the B---> D(0)D(-) and B(-) --> D(0)D(*-) channels are consistent with zero. 相似文献
95.
Sumisawa K Ushiroda Y Hazumi M Abe K Abe K Adachi I Aihara H Asano Y Aulchenko V Aushev T Bakich AM Bitenc U Bizjak I Blyth S Bondar A Bozek A Bracko M Brodzicka J Browder TE Chao Y Chen A Chen KF Chen WT Cheon BG Chistov R Choi Y Chuvikov A Cole S Dalseno J Danilov M Dash M Drutskoy A Eidelman S Enari Y Fang F Fratina S Gabyshev N Garmash A Gershon T Gokhroo G Golob B Gorisek A Haba J Hara K Hara T Hayashii H Higuchi T Hokuue T Hoshi Y Hou S Hou WS Hsiung YB Iijima T Imoto A Inami K Ishikawa A 《Physical review letters》2005,95(6):061801
We present a measurement of CP-violation parameters in the B0 --> K(s)0K(s)0K(s)0 decay based on a sample of 275 x 10(6) BB pairs collected at the upsilon(4S) resonance with the Belle detector at the KEKB energy-asymmetric e+e- collider. One neutral B meson is fully reconstructed in the decay B0 --> K(s)0K(s)0K(s)0, and the flavor of the accompanying B meson is identified from its decay products. CP-violation parameters are obtained from the asymmetry in the distributions of the proper-time interval between the two B decays: S = +1.26 +/- 0.68(stat) +/- 0.20(syst) and [symbol: see text] = +0.54 +/- 0.34(stat) +/- 0.09(syst). 相似文献
96.
Abe K Abe K Adachi I Aihara H Akatsu M Anipko D Asano Y Aushev T Aziz T Bahinipati S Bakich AM Banerjee S Bedny I Bitenc U Bizjak I Blyth S Bondar A Bozek A Bracko M Brodzicka J Chang P Chao Y Chen A Chen KF Chen WT Cheon BG Chistov R Choi SK Choi Y Chuvikov A Dalseno J Danilov M Dash M Drutskoy A Eidelman S Eiges V Fang F Fratina S Gabyshev N Garmash A Gershon T Gokhroo G Golob B Haba J Hastings NC Hayasaka K Hayashii H Hazumi M Higuchi T Hinz L Hokuue T Hoshi Y Hou S Hou WS Iijima T Imoto A 《Physical review letters》2005,94(22):221805
We report on the first observation of D0/1(2420)-->D0pi- pi+ and D+/1(2420-->D+ pi- pi+ decays (where the contribution from the dominant known D1-->D*pi decay mode is excluded) in the B- -->D0/1pi-) and (-)B0-->D+/1pi- decays, respectively. The observation is based on 15.2 x 10(7) B(-)B events collected with the Belle detector at the KEKB collider. We also set 90% confidence level upper limits for the branching fractions of the four following decays: B- -->D0/1pi-, D01-->D(*0)pi- pi+, (-)B0-->D+/1pi-, D+/1-->D(*+) pi- pi+, B- -->D(*0)2(2460)pi-, D(*0)2 -->D(*0) pi- pi+, (-)B0-->D(*+)2(2460)pi-, D(*+)2-->D(*+)pi- pi+. 相似文献
97.
Choi SK Olsen SL Abe K Abe K Adachi I Aihara H Asano Y Bahinipati S Bakich AM Ban Y Bedny I Bitenc U Bizjak I Bondar A Bozek A Bracko M Brodzicka J Browder TE Chang MC Chang P Chen A Chen WT Cheon BG Chistov R Choi Y Chuvikov A Cole S Dalseno J Danilov M Dash M Drutskoy A Eidelman S Enari Y Fang F Fratina S Gabyshev N Gershon T Gokhroo G Golob B Hara T Hastings NC Hayasaka K Hayashii H Hazumi M Hinz L Hokuue T Hoshi Y Hou S Hou WS Hsiung YB Iijima T Imoto A Inami K Ishikawa A Iwasaki M 《Physical review letters》2005,94(18):182002
We report the observation of a near-threshold enhancement in the omegaJ/psi invariant mass distribution for exclusive B-->KomegaJ/psi decays. The results are obtained from a 253 fb(-1) data sample that contains 275 x 10(6) BB pairs that were collected near the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric energy e(+)e(-) collider. The statistical significance of the omegaJ/psi mass enhancement is estimated to be greater than 8sigma. 相似文献
98.
Chao Y Chang P Abe K Abe K Aihara H Akai K Akatsu M Akemoto M Asano Y Aushev T Bahinipati S Bakich AM Bay A Bedny I Bitenc U Bizjak I Bondar A Bozek A Bracko M Brodzicka J Browder TE Chen A Chen KF Chen WT Cheon BG Chistov R Choi SK Choi Y Chuvikov A Dalseno J Danilov M Dash M Dragic J Drutskoy A Eidelman S Eiges V Enari Y Fang F Flanagan J Fratina S Furukawa K Gabyshev N Garmash A Gershon T Gokhroo G Golob B Haba J Hastings NC Hayasaka K Hayashii H Hazumi M Hinz L Hokuue T Hoshi Y Hou S Hou WS 《Physical review letters》2005,94(18):181803
We report the observation of the decay B0-->pi(0)pi(0), using a 253 fb(-1) data sample collected at the Upsilon(4S) resonance with the Belle detector at the KEKB e(+)e(-) collider. The measured branching fraction is B(B0-->pi(0)pi(0))=(2.3(+0.4+0.2)(-0.5-0.3))x10(-6), with a significance of 5.8 standard deviations including systematic uncertainties. We also make a measurement of the direct CP violating asymmetry in this mode. 相似文献
99.
Li J Zhang ZP Schwartz AJ Abe K Abe K Aihara H Akatsu M Asano Y Aushev T Bakich AM Bay A Bedny I Bitenc U Bizjak I Bondar A Bozek A Bracko M Brodzicka J Browder TE Chao Y Chen A Chen KF Chen WT Cheon BG Chistov R Choi SK Choi Y Chuvikov A Cole S Dalseno J 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 Haba J Hayasaka K Hayashii H Hazumi M Higuchi T Hokuue T Hoshi H Hou S Hou WS Iijima T Imoto A Inami K Itoh R Iwasaki M 《Physical review letters》2005,94(7):071801
We have searched for mixing in the D(0)-D (0) system by measuring the decay-time distribution of D(0) --> K(+) pi(-) decays. The analysis uses 90 fb(-1) of data collected by the Belle detector at the KEKB e(+) e(-) collider. We fit the decay-time distribution for the mixing parameters x' and y' and also for the parameter R(D), which is the ratio of the rate for the doubly-Cabibbo-suppressed decay D(0)--> K+ pi(-) to that for the Cabibbo-favored decay D(0)--> K-pi(+). We do these fits both assuming CP conservation and allowing for CP violation. We use a frequentist method to obtain a 95% C.L. region in the x'(2) - y' plane. Assuming no mixing, we measure R(D) = (0.381 +/- 0.017(+0.008)(-0.016))%. 相似文献
100.
Bizjak I Abe K Abe K Aihara H Asano Y Bahinipati S Bakich AM Ban Y Barberio E Barbero M Bay A Bitenc U Blyth S Bondar A Bozek A Bracko M Brodzicka J Browder TE Chao Y Chen A Chen WT Cheon BG Chistov R Choi SK Choi Y Choi YK Chuvikov A Cole S Dalseno J Danilov M Dash M Dong LY Drutskoy A Eidelman S Enari Y Fang F Fratina S Gabyshev N Garmash A Gershon T Gokhroo G Golob B Gorisek A Haba J Hara T Hayashii H Hazumi M Hinz L Hokuue T Hoshi Y Hou S Hou WS Iijima T Imoto A Inami K Ishikawa A Itoh R 《Physical review letters》2005,95(24):241801
We present a measurement of the Cabibbo-Kobayashi-Maskawa matrix element /Vub/, based on 253 fb(-1) of data collected by the Belle detector at the KEKB e+ e- asymmetric collider. Events are tagged by fully reconstructing one of the B mesons, produced in pairs from Gamma(4S). The signal for b --> u semileptonic decay is distinguished from the b --> c background using the hadronic mass Mx, the leptonic invariant mass squared q2 and the variable P+ [triple bond] Ex - /px/. The results are obtained for events with p(l)* > or = 1 GeV/c, in three kinematic regions (1) Mx < 1.7 GeV/c2, (2) Mx < 1.7 GeV/c2 combined with q2 > 8 GeV2/c2, and by (3) P+ < 0.66 GeV/c. The matrix element /Vub/ is found to be (4.09 +/- 0.19 +/- 0.20(+0.14) -0.15 +/- 0.18) x 10(-3), where the errors are statistical, systematic including Monte Carlo modeling, theoretical, and from shape function parameter determination, respectively. 相似文献