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.
100409752
Observation of B0 ---> a+-(1) (1260) pi-+
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.
207845948
Improved measurement of Anti-B0 ---> D(s)- D+ and search for anti-B0 ---> D(s)+ D(s)- at BELLE
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.
180004720
Observation of B ---> phi phi K Decays
118877314
A Study of elliptic flows in a quark combination model
We carry out a detail study of elliptic flows in Au-Au collisions at 200 AGeV in a quark combination model. We find that elliptic flow data for a variety of hadrons can be well reproduced except pions if constituent quarks with equal parallel transverse momenta combine into initially produced hadrons. In a combination mechanism where initial hadrons are formed by quarks with unequal parallel transverse momenta, theoretical predictions agree with data for all available hadrons including pions. The mass hierarchy at low transverse momenta in elliptic flows can be understood in the same quark combination mechanism as in the mediate range of transverse momenta.
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.
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.
119393401
Production rates for hadrons, pentaquarks Theta+ and Theta*++, and di-baryon (Omega Omega)(0+) in relativistic heavy ion collisions by a quark combination model
The hadron production in relativistic heavy ion collisions is well described by the quark combination model. The mixed ratios for various hadrons and the transverse momentum spectra for long-life hadrons are predicted and agree with recent RHIC data. The production rates for the pentaquarks $\Theta ^+$, $\Theta ^{*++}$ and the di-baryon $(\Omega\Omega)_{0^{+}}$ are estimated, neglecting the effect from the transition amplitude for constituent quarks to form an exotic state.
121208515
Multiplicity distributions in hadron-hadron collisions based on the universality ansatz
Recent experiments on small-${p}_{T}$ hadron production in $\mathrm{pp}$ collisions have shed new light on the apparent violation of the universality ansatz by the fact that the multiplicity dispersion in hadron-hadron collisions is much larger than that in ${e}^{+}{e}^{\ensuremath{-}}$ collisions. We present a model based on the universality ansatz, among other things. This model reproduces qualitatively the hadron multiplicity distributions in $\mathrm{pp}$ collisions over a wide range of energies. Within our framework, this essentially resolves the discrepancy stated above. In our approach the universality ansatz is also found to be applicable to the diffractive component events. This is supported by the inclusive $x$-distribution data having various specified number of prongs in the final states.