46391101
Determination of /Vub/ from measurements of the inclusive charmless semileptonic partial rates of B mesons using full reconstruction tags.
We present a measurement of the Cabibbo-Kobayashi-Maskawa matrix element /Vub/, based on 253 fb(-1) of data collected by the Belle detector at the KEKB e+ e- asymmetric collider. Events are tagged by fully reconstructing one of the B mesons, produced in pairs from Gamma(4S). The signal for b --> u semileptonic decay is distinguished from the b --> c background using the hadronic mass Mx, the leptonic invariant mass squared q2 and the variable P+ [triple bond] Ex - /px/. The results are obtained for events with p(l)* > or = 1 GeV/c, in three kinematic regions (1) Mx < 1.7 GeV/c2, (2) Mx < 1.7 GeV/c2 combined with q2 > 8 GeV2/c2, and by (3) P+ < 0.66 GeV/c. The matrix element /Vub/ is found to be (4.09 +/- 0.19 +/- 0.20(+0.14) -0.15 +/- 0.18) x 10(-3), where the errors are statistical, systematic including Monte Carlo modeling, theoretical, and from shape function parameter determination, respectively.
100409752
Observation of B0 ---> a+-(1) (1260) pi-+
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.
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.
200108193
Time-dependent CP asymmetries in b ---> s anti-q q transitions and sin 2 phi(1) in B0 ---> j/psi K0 decays with 386 million B anti-B pairs
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.
17880016
COLOR AND KINEMATIC INTERFERENCE INFLUENCE ON THE PROBABILITY OF COLOR SINGLET CHAIN STATES
In popular event generators of high energy reaction, the large Nc, the number of color approximation is implied, which reduces the possible interference effects, and the probability of color singlet chain reaches to about 100%. In $Nc=3$ real world, we show that not only the color interference decreases this probability to 83%, 77%, 72%, $...$, respectively to $n=2$, 3, 4, $...$, {in the process of}$e^+e^-{\longrightarrow}q\bar {q}+ng$ final state, but also the accompanying kinematic interference exists, which decreases this probability to about 67%, 58%, $...$, further. In the meanwhile, we fin d that the kinematic interference makes the probability of color separate singlet states increases synchronously. Combing and analyzing above facts, we infer that the probability of color singlet chain states in high energy ${e^+e^-}{\longrightarrow}{h's}$ reaction would be much smaller than 100%, which is commonly accepted. And the fraction of other color connec tion states, $e.g.$, color separate singlet states should be significant.
121688568
A derivation of the heavy quark fragmentation function in annihilation
We extend the kinematic analysis on heavy quark fragmentation initiated by Bjorken and Suzuki to derive the fragmentation function of the heavy quarks. Considering the thrust axis is not necessarily along the relative momentum direction of the initial quark pair, indeed the contribution of the heavy hadrons which locate at non-leading rapidity positions may be as important to the results as those at the leading position. A quite good agreement between data and our prediction is achieved.
119403465
Study of baryon anti-baryon rapidity correlation in e+ e- annihilation by quark combination model
We use Quark Combination Model to study baryon antibaryon rapidity correlation in e^+e^- annihilation and compare our predictions with the available data. We find that these results and relevant properties are all consistent with data. So the evidence to rule out Quark Combination Model which has long been cited in literatures does not exist.
197513358
Charm hadron production at RHIC in combination model
We investigate the charm hadron production in relativistic heavy-ion collisions with the quark combination model. The $p_{T}$ dependencies of the charm baryon to meson ratios such as $\frac{\Lambda_{c}+\bar{\Lambda}_{c}}{D^{0}+\bar{D}^{0}}$, $\frac{\Lambda_{c}+\bar{\Lambda}_{c}}{D^{+}+D^{-}}$ and $\frac{\Lambda_{c}+\bar{\Lambda}_{c}}{D_{s}^{+}+D_{s}^{-}}$ in Au+Au collisions at 200 GeV are obtained. The charm baryon enhancement in the intermediate $p_{T}$ range is very prominent, which further, together with the strangeness enhancement, affect the charm hadron ratios and lead to a $\sim17%$ larger charm cross-section given by PHENIX. The dependencies of the charm hadron ratios on energy, centrality, and other parameters are also investigated. Predictions of the charm hadron ratios for the upgrade of RHIC and for LHC are presented.
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.