Observation of B+-->psi(3770)K+

We report the first observation of the decay B+-->psi(3770)K+ where the psi(3770) is reconstructed in the D0(-)D(0) and D+D- decay channels. The obtained branching fraction is B(B+-->psi(3770)K+)=(0.48+/-0.11+/-0.07)x10(-3). We have measured the branching fraction for the decay B+-->D0(-)D0K+ to be (1.17+/-0.21+/-0.15)x10(-3) and set a 90% confidence level upper limit of 0.90 x 10(-3) for the decay B+-->D+D-K+. We also present the results of a search for possible decays to D(-)D and D0(-)D(0)pi(0) of the recently observed X(3872) particle. The analysis is based on 88 fb(-1) of data collected at the Upsilon(4S) resonance by the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider.     

Measurement of polarization and triple-product correlations in B-->phiK* decays

We present measurements of decay amplitudes and triple-product correlations in B-->phiK* decays based on 253 fb(-1) of data recorded at the Upsilon(4S) resonance with the Belle detector at the KEKB e(+)e(-) storage ring. The decay amplitudes for the three different helicity states are determined from the angular distributions of final-state particles. The longitudinal polarization amplitudes are found to be 0.45 +/- 0.05 +/- 0.02 for B0-->phiK(*0) and 0.52 +/- 0.08 +/- 0.03 for B+ -->phiK(*+) decays. CP- and T-odd CP-violating triple-product asymmetries are measured to be consistent with zero.     

Observation of B+-->K1(1270)+gamma

We report the observation of the radiative decay B+-->K1(1270)(+) gamma using a data sample of 140 fb(-1) taken at the Upsilon(4S) resonance with the Belle detector at the KEKB e+e- collider. We find the branching fraction to be B(B+-->K1(1270)(+)gamma)=(4.3+/-0.9(stat.)+/-0.9(syst.))x10(-5) with a significance of 7.3sigma. We find no significant signal for B+-->K1(1400)(+)gamma and set an upper limit B(B+-->K1(1400)(+)gamma)<1.5 x 10(-5) at the 90% confidence level. We also measure inclusive branching fractions for B+-->K+pi+pi-gamma and B0-->K0pi+pi-gamma in the mass range 1 GeV/c(2)相似文献   

Measurement of branching fractions and polarization in B-->phiK(*) decays

We present the first measurement of decay amplitudes in B-->phiK* and measurements of branching fractions in B-->phiK(*) decays based on 78.1 fb(-1) of data recorded at the Upsilon(4S) resonance with the Belle detector at the KEKB e+e- storage ring. The decay amplitudes for the different phiK*0 helicity states are measured from the angular distributions of final state particles in the transversity basis. The longitudinal and transverse complex amplitudes are |A0|2=0.43+/-0.09+/-0.04, |A(perpendicular)|2=0.41+/-0.10+/-0.04, arg((A(parallel))=-2.57+/-0.39+/-0.09, and arg((A(perpendicular))=0.48+/-0.32+/-0.06. The direct CP-violating asymmetries are found to be consistent with zero.     

The Reggeon Field Theory and finite scales at collider energies

The Reggeon Field Theory (RFT) with attention paid to finite “flavoring” rapidity scales is considered in the light of emerging SPS collider data. Predictions from a simple RFT perturbative model made in 1978 are shown to be consistent with σ_tot and other data, in both theP?f identity andP+f versions. The RFT scaling laws are judged not applicable without large non-leading terms, implying an asymptotic region beyond the collider.     

A short and stereoselective synthesis of functionalized pentenomycin derivatives

A short and stereoselective synthesis of 2-hydroxymethyl-4-deoxypentenomycin and 2-hydoxymethylpentenomycin derivatives is accomplished in five and seven steps starting from tetrabromonorbornyl derivatives in overall yields of 41% and 38%, respectively.     

Studies on the prospects of GaInAs and GaInAsP for double-drift region heterostructure IMPATTs

Double heterojunctions having the material combinations InP/GaInAs/InP, GaAs/GaInAs/GaAs and InP/GaInAsP/InP have been studied to assess their potential for double-drift region (DDR) IMPATT diodes. An accurate and realistic computer simulation program has been framed and used for the dc and high-frequency analysis of the DDRs. The analysis is carried out both in IMPATT (IMPact Avalanche Transit Time) and MITATT (MIxed Tunnelling Avalanche Transit Time) modes. Our results indicate that the GaAs/GaInAs/GaAs DDR would provide the best mm-wave performance up to sufficiently high frequencies. Further, the performance of the DDR diodes is observed to deteriorate at high frequency of operation due to phase distortion introduced by tunnel injected current, which is found to be the least in the case of GaAs/GaInAs/GaAs DDR leading to the best performance of this DDR amongst the three.