11572239
Observation of B decays to two kaons.
Using 449x10(6) BB[over ] pairs collected with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider, we observe clear signals for B(+)-->K[over ](0)K(+) and B(0)-->K[over ](0)K(0) decays with 5.3sigma and 6.0sigma significance, respectively. We measure the branching fractions B(B(+)-->K[over ](0)K(+))=(1.22(-0.28-0.16)(+0.32+0.13))x10(-6) and B(B(0)-->K[over ](0)K(0))=(0.87(-0.20)(+0.25)+/-0.09)x10(-6), and partial-rate asymmetries A(CP)(B(+)-->K[over ](0)K(+))=0.13(-0.24)(+0.23)+/-0.02 and A(CP)(B(0)-->K[over ](0)K(0))=-0.58(-0.66)(+0.73)+/-0.04. From a simultaneous fit, we also obtain B(B(+)-->K(0)pi(+))=(22.8(-0.7)(+0.8)+/-1.3)x10(-6) and A(CP)(B(+)-->K(0)pi(+))=0.03+/-0.03+/-0.01. The first and second error in the branching fractions and the partial-rate asymmetries are statistical and systematic, respectively. No signal is observed for B(0)-->K(+)K(-) decays, and for this branching fraction, we set an upper limit of 4.1x10(-7) at the 90% confidence level.
123671853
Studies of CP violation in B0 ---> J / psi K*0 decays
122551951
Search for B ---> tau nu and B ---> K nu anti-nu decays with a fully reconstructed B at Belle
208857229
New search for tau -> mu gamma and tau -> e gamma decays at Belle
We report on a search for the lepton flavor violating tau(-) -> mu(-)gamma and tau(-) -> e(-)gamma decays based on 535 fb(-1) of data accumulated at the Belle experiment. No signal is found and we set 90% confidence level upper limits on the branching ratios B(tau(-) -> mu(-)gamma) e(-)y) < 1.2 x 10(-7). (c) 2008 Elsevier B.V. All rights reserved.
40146055
Measurement of forward-backward asymmetry and Wilson coefficients in B --> K*l+l-.
We report the first measurement of the forward-backward asymmetry and the ratios of Wilson coefficients and in A9/A7 and A10/A7 in B --> K*l+l-, where l represents an electron or a muon. We find evidence for the forward-backward asymmetry with a significance of 3.4sigma. The results are obtained from a data sample containing 386 x 10(6) BB pairs that were collected on the Y(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider.
44272712
Improved evidence for direct CP violation in B0-->pi+pi- decays and model-independent constraints on phi2.
We present a new measurement of the time-dependent CP-violating parameters in B(0)--> pi(+)pi(-) decays with 275 x 10(6) BB pairs collected with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider operating at the Gamma(4S) resonance. We find 666 +/- 43 B(0) --> pi(+)pi(-) events and measure the CP-violating parameters: S(pipi) = -0.67 +/- 0.16(stat) +/- 0.06(syst) and A(pipi) = +0.56 +/- 0.12(stat) +/- 0.06(syst). We find evidence for large direct CP violation with a significance greater than 4 standard deviations for any S(pipi) value. Using isospin relations, we obtain 95.4% confidence intervals for the Cabibbo-Kobayashi-Maskawa quark-mixing matrix angle phi(2) of 0 degree < phiv(2) < 19 degrees and 71 degrees < phi(2) < 180 degrees.
124806737
Fragmentation of Light Initial Quarks into Charm Measons in e~+ e~- Annihilation
We study the process that the light initial quarks produced in e+ e- annihilation combine with the c from glu-on splitting to form D's (D-+D6-+D0) or D 's(D-*+ Ds*-+D*0). The 'light + heavy' bound state is described by light-cone wavefunction. The contribution of this process to D (D ) production at Z0 pole is much larger compared with that in lower energies (e.g. 10.6GeV) . For this special process, the invariant mass of D(D ) and the charm had-ron fragmented from the c quark has a unique spectrum which peaks near 2 MB if we constrain the D(D*) from all processes with energy larger than 20GeV. It is also noticeable that the produced D* in this process is dominantly longitudinally polarized, which is consistent with the OPAL data.
11928091
Probability of color rearrangement at partonic level in hadronic W+W− decays
Abstract A strict method to calculate the color rearrangement probability at partonic level in hadronic W + W − decays is proposed. The color effective Hamiltonian H c is constructed from invariant amplitude for the process e + e − → W + W − → q 1 q 2 q 3 q 4 + ng ( n = 0, 1, 2, …) and is used to calculate the cross sections of various color singlets and the color rearrangement probability. The true meaning of the color rearrangement is clarified and its difference from color interference is discussed.
119452619
Charged-particle rapidity density in Au+Au collisions in a quark combination model
Rapidity/pseudorapidity densities for charged particles and their centrality, rapidity, and energy dependence in Au+Au collisions at the Relativistic Heavy Ion Collider are studied in a quark combination model. Using a Gaussian-type rapidity distribution for constituent quarks as a result of Landau hydrodynamic evolution, the data at {radical}(s{sub NN})=130,200 GeV at various centralities in full pseudorapidity range are well described, and the charged-particle multiplicities are reproduced as functions of the number of participants. The energy dependence of the shape of the dN{sub ch}/d{eta} distribution is also described at various collision energies {radical}(s{sub NN})=200,130,62.4 GeV in central collisions with same value of parameters except 19.6 GeV. The calculated rapidity distributions and yields for the charged pions and kaons in central Au+Au collisions at {radical}(s{sub NN})=200 GeV are compared with experimental data of the BRAHMS Collaboration.
125000735
THE HEAVY QUARK FRAGMENTATION FUNCTION AND THE MULTIPLICITY DIFFERENCE BETWEEN HEAVY AND LIGHT QUARK HADRONIC EVENTS IN e+e- ANNIHILATION IN THE LONGITUDINAL PHASE SPACE MODEL
The heavy quark fragmentation function and the multiplicity difference between heavy and light quark hadronic events are explained in a unified framework, namely the longitudinal phase space model. Good agreement of the predictions with data has been achieved.
120171906
Production percentages of excited baryons in e+e- annihilation
Two relations between the production weights for octet, decuplet (including both the ground and excited states) and singlet baryons are derived using the properties of hadronization in the stochastic quark combination scheme. From the basic relations, it is easy to understand the "spin suppression" phenomenon and the reason why singlet baryons have high multiplicities. A method for estimating the production percentages of the lowest excited baryons is given.