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971.
Zelakiewicz BS Lica GC Deacon ML Tong Y 《Journal of the American Chemical Society》2004,126(32):10053-10058
On 13C1-labeled octanethiol-protected 2.7 nm Pd nanoparticle surfaces, it has been observed that the 13C1 NMR of the alpha-carbon shows a peak centered around 38 ppm (with respect to tetramethylsilane (TMS)), which virtually coincides with that of the alpha-carbons in a dioctyl-disulfide molecule (39.3 ppm), and the corresponding 13C1 spin-spin relaxation becomes nonexponential. In addition, the infrared spectrum of the same sample shows that the ligands have a 100% gauche conformation, which is also consistent with a dioctyl-disulfide arrangement. By comparing with data obtained on 13C1-labeled octanethiol-protected 2.8 nm Au nanoparticles, we propose that a dioctyl-disulfide structure of the ligands is formed on the octanethiol-protected Pd nanoparticle surface, in contrast to the thiolate structure proposed on the Au nanoparticles. In addition, CO adsorption experiments show no sign of a PdS layer formed on the Pd nanoparticle surface. Furthermore, data taken over a period of more than 1 year show that the Pd nanoparticles are rather stable in organic solvents (for instance benzene), although slow degradation does happen and oxygen seems to play an important role in accelerating the degradation. 相似文献
972.
Simple organocopper reagents are shown to undergo anti-stereoselective 1,4-addition to menthyloxy-substituted lactone 1 in the presence of BF3.OEt2; the Lewis acid causes partial epimerisation of the acetal centre after conjugate addition. Enolate alkylation of the adducts leads to di- and trisubstituted lactones that are converted, in favourable cases, into di- and trisubstituted cyclopentenones. 相似文献
973.
Aubert B Barate R Boutigny D Couderc F Gaillard JM Hicheur A Karyotakis Y Lees JP Tisserand V Zghiche A Palano A Pompili A Chen JC Qi ND Rong G Wang P Zhu YS Eigen G Ofte I Stugu B Abrams GS Borgland AW Breon AB Brown DN Button-Shafer J Cahn RN Charles E Day CT Gill MS Gritsan AV Groysman Y Jacobsen RG Kadel RW Kadyk J Kerth LT Kolomensky YG Kukartsev G Lynch G Mir LM Oddone PJ Orimoto TJ Pripstein M Roe NA Ronan MT Shelkov VG Wenzel WA Barrett M Ford KE Harrison TJ Hart AJ Hawkes CM Morgan SE 《Physical review letters》2004,93(20):201801
We present a measurement of the time-dependent CP-violating asymmetries in B0-->K(*0)gamma(K(*0)-->K(0)(S)pi(0)) decays based on 124 x 10(6) Upsilon(4S)-->BB decays collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at the Stanford Linear Accelerator Center. In a sample containing 105+/-14 signal decays, we measure S(K(*)gamma)=0.25+/-0.63+/-0.14 and C(K(*)gamma)=-0.57+/-0.32+/-0.09, where the first error is statistical and the second, systematic. 相似文献
974.
Aubert B Barate R Boutigny D Couderc F Gaillard JM Hicheur A Karyotakis Y Lees JP Tisserand V Zghiche A Palano A Pompili A Chen JC Qi ND Rong G Wang P Zhu YS Eigen G Ofte I Stugu B Abrams GS Borgland AW Breon AB Brown DN Button-Shafer J Cahn RN Charles E Day CT Gill MS Gritsan AV Groysman Y Jacobsen RG Kadel RW Kadyk J Kerth LT Kolomensky YG Kukartsev G Lynch G Mir LM Oddone PJ Orimoto TJ Pripstein M Roe NA Ronan MT Shelkov VG Wenzel WA Barrett M Ford KE Harrison TJ Hart AJ Hawkes CM Morgan SE 《Physical review letters》2004,93(23):231804
With a sample of about 227x10(6) BB pairs recorded with the BABAR detector we perform a full angular analysis of the decay B0-->phiK(*0)(892). We make novel measurements of five parameters sensitive to CP violation. We also measure the branching fraction to be (9.2+/-0.9+/-0.5)x10(-6) and determine the fractions of longitudinal and parity-odd transverse contributions as f(L)=0.52+/-0.05+/-0.02 and f( perpendicular)=0.22+/-0.05+/-0.02. The phases of the parity-even and parity-odd transverse amplitudes relative to the longitudinal amplitude are found to be phi( parallel)=2.34(+0.23)(-0.20)+/-0.05 rad and phi( perpendicular)=2.47+/-0.25+/-0.05 rad. We also observe the decay B0-->phiK(*0)(1430). 相似文献
975.
Aubert B Barate R Boutigny D Couderc F Gaillard JM Hicheur A Karyotakis Y Lees JP Tisserand V Zghiche A Palano A Pompili A Chen JC Qi ND Rong G Wang P Zhu YS Eigen G Ofte I Stugu B Abrams GS Borgland AW Breon AB Brown DN Button-Shafer J Cahn RN Charles E Day CT Gill MS Gritsan AV Groysman Y Jacobsen RG Kadel RW Kadyk J Kerth LT Kolomensky YG Kukartsev G Leclerc C Lynch G Merchant AM Mir LM Oddone PJ Orimoto TJ Pripstein M Roe NA Ronan MT Shelkov VG Telnov AV Wenzel WA Ford K Harrison TJ 《Physical review letters》2004,93(13):131804
We search for B+/--->[K(-/+)pi(+/-)](D)K+/- decays, where [K(-/+)pi(+/-)](D) indicates that the K-/+pi(+/-) pair originates from the decay of a D0 or D (0). Results are based on 120x10(6) Upsilon(4S)-->BB decays collected with the BABAR detector at SLAC. We set an upper limit on the ratio R(Kpi) identical with[Gamma(B+-->[K(-)pi(+)](D)K+)+Gamma(B--->[K(+)pi(-)](D)K-)][Gamma(B+-->[K(+)pi(-)](D) / K+)+Gamma(B--->[K(-)pi(+)](D)K-)]<0.026 (90% C.L.). This constrains the amplitude ratio r(B) identical with|A(B--->D 0K-)/A(B--->D0K-)|<0.22 (90% C.L.), consistent with expectations. The small value of r(B) favored by our analysis suggests that the determination of the Cabibbo-Kobayashi-Maskawa phase gamma from B-->DK will be difficult. 相似文献
976.
Aubert B Barate R Boutigny D Couderc F Gaillard JM Hicheur A Karyotakis Y Lees JP Tisserand V Zghiche A Palano A Pompili A Chen JC Qi ND Rong G Wang P Zhu YS Eigen G Ofte I Stugu B Abrams GS Borgland AW Breon AB Brown DN Button-Shafer J Cahn RN Charles E Day CT Gill MS Gritsan AV Groysman Y Jacobsen RG Kadel RW Kadyk J Kerth LT Kolomensky YG Kukartsev G Leclerc C Lynch G Merchant AM Mir LM Oddone PJ Orimoto TJ Pripstein M Roe NA Ronan MT Shelkov VG Telnov AV Wenzel WA Ford K Harrison TJ 《Physical review letters》2004,93(13):131805
We present a measurement of the time-dependent CP-violating (CPV) asymmetries in B0-->K(0)(S)pi(0) decays based on 124x10(6) Upsilon(4S)-->BB decays collected with the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC. In a sample containing 122+/-16 signal decays, we obtain the magnitudes of the direct CPV asymmetry CK(0)(S)(pi(0))=0.40(+0.27)(-0.28)+/-0.09 and of the CPV asymmetry in the interference between mixing and decay SK(0)(S)(pi(0))=0.48(+0.38)(-0.47)+/-0.06 where the first error is statistical and the second systematic. 相似文献
977.
Aubert B Barate R Boutigny D Couderc F Gaillard JM Hicheur A Karyotakis Y Lees JP Robbe P Tisserand V Zghiche A Palano A Pompili A Chen JC Qi ND Rong G Wang P Zhu YS Eigen G Ofte I Stugu B Abrams GS Borgland AW Breon AB Brown DN Button-Shafer J Cahn RN Charles E Day CT Gill MS Gritsan AV Groysman Y Jacobsen RG Kadel RW Kadyk J Kerth LT Kolomensky YG Kukartsev G LeClerc C Levi ME Lynch G Mir LM Oddone PJ Orimoto TJ Pripstein M Roe NA Romosan A Ronan MT Shelkov VG Telnov AV Wenzel WA Ford K 《Physical review letters》2004,93(5):051802
We present measurements of branching fractions and charge asymmetries in B-meson decays to rho(+)pi(0), rho(0)pi(+), and rho(0)pi(0). The data sample comprises 89x10(6) Upsilon(4S)-->BBmacr; decays collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. We find the charge-averaged branching fractions B(B+-->rho(+)pi(0))=[10.9+/-1.9(stat)+/-1.9(syst)]x10(-6) and B(B+-->rho(0)pi(+))=(9.5+/-1.1+/-0.9)x10(-6), and we set a 90% confidence-level upper limit B(B0-->rho(0)pi(0))<2.9x10(-6). We measure the charge asymmetries ACP(pi(0))(rho(+))=0.24+/-0.16+/-0.06 and ACP(pi(+))(rho(0))=-0.19+/-0.11+/-0.02. 相似文献
978.
Aubert B Barate R Boutigny D Gaillard JM Hicheur A Karyotakis Y Lees JP Robbe P Tisserand V Zghiche A Palano A Pompili A Chen JC Qi ND Rong G Wang P Zhu YS Eigen G Ofte I Stugu B Abrams GS Borgland AW Breon AB Brown DN Button-Shafer J Cahn RN Charles E Day CT Gill MS Gritsan AV Groysman Y Jacobsen RG Kadel RW Kadyk J Kerth LT Kolomensky YG Kukartsev G LeClerc C Levi ME Lynch G Mir LM Oddone PJ Orimoto TJ Pripstein M Roe NA Romosan A Ronan MT Shelkov VG Telnov AV Wenzel WA Ford K Harrison TJ 《Physical review letters》2004,92(20):202002
We present a study of B--->D(0)(CP)K- decays, where D(0)(CP) is reconstructed in CP-even channels, based on a sample of 88.8 x 10(6) Upsilon(4S)-->BB decays collected with the BABAR detector at the PEP-II e(+)e(-) storage ring. We measure the ratio of Cabibbo-suppressed to Cabibbo-favored branching fractions B(B--->D(0)(CP)K-)/B(B--->D(0)(CP)pi(-))=[8.8+/-1.6(stat)+/-0.5(syst)]x10(-2) and the CP asymmetry A(CP)=0.07+/-0.17(stat)+/-0.06(syst). We also measure B(B--->D0K-)/B(B--->D0pi(-))=[8.31+/-0.35(stat)+/-0.20(syst)]x10(-2) using a sample of 61.0 x 10(6) BB pairs. 相似文献
979.
Aubert B Barate R Boutigny D Couderc F Gaillard JM Hicheur A Karyotakis Y Lees JP Robbe P Tisserand V Zghiche A Palano A Pompili A Chen JC Qi ND Rong G Wang P Zhu YS Eigen G Ofte I Stugu B Abrams GS Borgland AW Breon AB Brown DN Button-Shafer J Cahn RN Charles E Day CT Gill MS Gritsan AV Groysman Y Jacobsen RG Kadel RW Kadyk J Kerth LT Kolomensky YG Kukartsev G LeClerc C Levi ME Lynch G Mir LM Oddone PJ Orimoto TJ Pripstein M Roe NA Romosan A Ronan MT Shelkov VG Telnov AV Wenzel WA Ford K 《Physical review letters》2004,92(20):201802
We present measurements of branching fractions and CP-violating asymmetries in decays of B mesons to two-body final states containing a K0. The results are based on a data sample of approximately 88 x 10(6) Upsilon(4S)-->BB decays collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. We measure B(B+-->K(0)pi(+))=(22.3+/-1.7+/-1.1)x10(-6), B(B0-->K(0)pi(0)=(11.4+/-1.7+/-0.8)x10(-6), B(B+-->K(0)K+)<2.5 x 10(-6), and B(B0-->K(0)K(0)<1.8 x 10(-6), where the first uncertainty is statistical and the second is systematic, and the upper limits are at the 90% confidence level. In addition, the following CP-violating asymmetries have been measured: A(CP)(B+-->K(0)pi(+))=-0.05+/-0.08+/-0.01 and A(CP)(B0-->K(0)pi(0)=0.03+/-0.36+/-0.11. 相似文献
980.
Aubert B Barate R Boutigny D Gaillard JM Hicheur A Karyotakis Y Lees JP Robbe P Tisserand V Zghiche A Palano A Pompili A Chen JC Qi ND Rong G Wang P Zhu YS Eigen G Ofte I Stugu B Abrams GS Borgland AW Breon AB Brown DN Button-Shafer J Cahn RN Charles E Day CT Gill MS Gritsan AV Groysman Y Jacobsen RG Kadel RW Kadyk J Kerth LT Kolomensky YG Kral JF Kukartsev G LeClerc C Levi ME Lynch G Mir LM Oddone PJ Orimoto TJ Pripstein M Roe NA Romosan A Ronan MT Shelkov VG Telnov AV Wenzel WA Ford K 《Physical review letters》2004,92(14):142002
The mass m(eta(c)) and total width Gamma(eta(c))(tot) of the eta(c) meson have been measured in two-photon interactions at the SLAC e(+)e(-) asymmetric B Factory with the BABAR detector. With a sample of approximately 2500 reconstructed eta(c)-->K(0)(S)K+/-pi(-/+) decays in 88 fb(-1) of data, the results are m(eta(c))=2982.5+/-1.1(stat)+/-0.9(syst) MeV/c(2) and Gamma(eta(c))(tot)=34.3+/-2.3(stat)+/-0.9(syst) MeV/c(2). Using the same decay mode, a second resonance with 112+/-24 events is observed with a mass of 3630.8+/-3.4(stat)+/-1.0(syst) MeV/c(2) and width of 17.0+/-8.3(stat)+/-2.5(syst) MeV/c(2). This observation is consistent with expectations for the eta(c)(2S) state. 相似文献