B Meson Decay To Pseudoscalar Or Vector Meson Under Light Cone Sum Rule

In dealing with the processes of B meson decay to light mesons, QCD light-cone sum rule(LCSR) is a very effective method. In different with traditional SVZ sum rule, LCSR is expanded near the light cone x2�'0. At the same time, the non-perturbative dynamisc are factorized into light-cone distribution amplitudes(LCDA), which are expanded according to “twist”, i.e. the difference between spin and dimension. Considering the polarization of vector meson, the LCDAs are increased. Here, we mainly use the δ ~ mV/ mb to separate the LCDAs instead of twist. In the traditional LCSR, we must dealing with every LCSR, which have large uncertainties.In this paper, we mainly use the chiral current as the interpolation field to discuss a series of B meson semileptonic decay instead the axial current used in traditional LCSR, such as B ®D n, B ®nr, B K*m m+ -®. For the process B ®D n, we mainly take the right-handed current correlator, and get the transition form factor(TFF) with twist-2,4 LCDAs, which has removed the large uncertainty coming from twist-3 LCDA. As for B ®nr, we take right-handed and left-handed current correlators to get the LCSRs of TFFs with δ0, δ2-order and δ1, δ3-order LCDAs. In dealing with the process B K* m m+ -®, we use right-handed current correlator to make a detail discussion about the tensor TFFs T1,2,3 and 3T% apart from axial-vector and vector TFFs. We also make a detail discussion about the parameters in LCSR, i.e. Borel parameter and continuous state threshould, which the contribution coming from the continuum state can reach 25% ~ 30%, or more less. The contribution of the higher twist DAs are less than 10%.On the other hand, we give leading twist LCDAs of the heavy pseudoscale D meson, vector ρmeson and K* meson completely. Firstly, we consider the The spin effects of LCDA, and the SU(3) symmetry breaking from the s-quark mass. Meanwhile, we consider the factorization scale dependence of the LCDA. In dealing with the chiral-even DAs, we give the curves of twist-3 DAs with the WW approach. From the analysis, we can see that the WH-DA changed with the free parameter, contain the curves coming from the Chernyak and Zhinitsky(CZ) DA, Ad S/QCD-DA, which also proved our prediction for pseudoscale meson and vector meson generality.In order to improve the rationalisation of our improved LCSR and make a accurate determine to the free parameter of WH model, we take the double pole formula to make the results analytical extension to the full space and use Δ ≤ 1 % as criterion. The final result are agree with the prediction coming from lattice. At the same time, by take the formulas of differential decay width, we give the total decay width, CKM matrix element, decay branching ratio, coming form improved LCSR. For the process B ®D, we have | Vcb| equals to(40.84 ± 3.11),(39.08 ± 3.03) and(37.59 ± 2.89)×10-3 with BD=0, 0.1, 0.2. | Vub| are3(2.91 0.19) 10-± ′ with 2;B0.2r^= - and 3(2.91 0.35) 10-± ′ with 2;B0.1r=P, in dealing with right-handed current of B ®r process. As for B ®K*, we have ( )* 0.071 60.036(B K m m) 1.113 10+ - + --B® = ′ with *2;0.1KB^=. The result have a good agreement with Lattice, LHCb、BABAR、Belle、CDF predictions.Finally, we can give the suggestion about the free parameter of the LCDA. It can also prove our theory meet the self-consistent and rationality by comparing with the moment of WH-DA.