排序方式: 共有115条查询结果,搜索用时 0 毫秒
111.
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》2003,91(24):241801
We present a study of the decay B0-->pi(0)pi(0) based on a sample of 124 x 10(6) BB pairs recorded by the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. We observe 46+/-13+/-3 events, where the first error is statistical and the second is systematic, corresponding to a significance of 4.2 standard deviations including systematic uncertainties. We measure the branching fraction B(B0-->pi(0)pi(0))=(2.1+/-0.6+/-0.3)x10(-6), averaged over B0 and B(0) decays. 相似文献
112.
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》2003,91(12):121801
We present a measurement of D0-macro D0 mixing parameters using the ratios of lifetimes extracted from samples of D0 mesons decaying to K-pi(+), K-K+, and pi(-)pi(+). Using 91 fb(-1) of data collected by the BABAR detector at the PEP-II asymmetric-energy B Factory, we obtain a value Y=[0.8+/-0.4(stat.)(+0.5)(-0.4)(syst.)]%, which, in the limit of CP conservation, corresponds to the mixing parameter y=Delta Gamma/2 Gamma. Using the difference in lifetimes of D0 and macro D0 mesons, we obtain the CP-violation parameter Delta Y=[-0.8+/-0.6(stat.)+/-0.2(syst.)]%. 相似文献
113.
Aubert B 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 Gill MS Gritsan AV Groysman Y Jacobsen RG Kadel RW Kadyk J Kerth LT Kolomensky YG Kral JF 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 Harrison TJ Hawkes CM Knowles DJ 《Physical review letters》2003,90(9):091801
We present a measurement of the branching fraction for the decay of the neutral B meson into the final state J/psipi(+)pi(-). The data set contains approximately 56 x 10(6) BB pairs produced at the Upsilon(4S) resonance and recorded with the BABAR detector at the PEP-II asymmetric-energy e(+)e(-) storage ring. The result of this analysis is B(B0-->J/psipi(+)pi(-))=(4.6+/-0.7+/-0.6) x 10(-5), where the first error is statistical and the second is systematic. In addition, we measure B(B0-->J/psirho(0))=(1.6+/-0.6+/-0.4) x 10(-5). 相似文献
114.
Unfilled and ytterbium (Yb)‐filled cobalt antimony (CoSb3) nanoparticles were synthesized via solvothermal route using sodium borohydride (NaBH4) as a reducing agent. The effect of various amounts of sodium borohydride on the formation of as‐synthesized CoSb3 nanoparticles with pure phase was investigated. It is found that a sufficient amount of NaBH4 was required in order to form pure phase CoSb3. In addition, the effect of annealing time and temperature on the phase transformation of the as‐prepared non‐pure phase CoSb3 sample was also investigated. It is found that annealing at 500 °C for 5 h would eliminate those non‐CoSb3 phases and result in pure cubic skutterudite phase CoSb3. Structural characterization of the as‐prepared unfilled and Yb‐filled nanoparticles was carried out with transmission electron microscopy (TEM) which revealed the formation of highly crystalline cubic phase of skutterudite Yb‐filled CoSb3. Laser induced breakdown spectroscopy (LIBS) confirmed the presence of ytterbium in the Yb‐filled CoSb3 samples. 相似文献
115.
Abe S Ebihara T Enomoto S Furuno K Gando Y Ichimura K Ikeda H Inoue K Kibe Y Kishimoto Y Koga M Kozlov A Minekawa Y Mitsui T Nakajima K Nakajima K Nakamura K Nakamura M Owada K Shimizu I Shimizu Y Shirai J Suekane F Suzuki A Takemoto Y Tamae K Terashima A Watanabe H Yonezawa E Yoshida S Busenitz J Classen T Grant C Keefer G Leonard DS McKee D Piepke A Decowski MP Detwiler JA Freedman SJ Fujikawa BK Gray F Guardincerri E Hsu L Kadel R Lendvai C Luk KB Murayama H O'Donnell T Steiner HM Winslow LA 《Physical review letters》2008,100(22):221803
The KamLAND experiment has determined a precise value for the neutrino oscillation parameter Deltam21(2) and stringent constraints on theta12. The exposure to nuclear reactor antineutrinos is increased almost fourfold over previous results to 2.44 x 10(32) proton yr due to longer livetime and an enlarged fiducial volume. An undistorted reactor nu[over]e energy spectrum is now rejected at >5sigma. Analysis of the reactor spectrum above the inverse beta decay energy threshold, and including geoneutrinos, gives a best fit at Deltam21(2)=7.58(-0.13)(+0.14)(stat) -0.15+0.15(syst) x 10(-5) eV2 and tan2theta12=0.56(-0.07)+0.10(stat) -0.06+0.10(syst). Local Deltachi2 minima at higher and lower Deltam21(2) are disfavored at >4sigma. Combining with solar neutrino data, we obtain Deltam21(2)=7.59(-0.21)+0.21 x 10(-5) eV2 and tan2theta12=0.47(-0.05)+0.06. 相似文献