We reconsider and update the QCD light-cone sum rules for $B\to π$ form factors. The gluon radiative corrections to the twist-2 and twist-3 terms in the correlation functions are calculated. The $\bar{MS}$ $b$-quark mass is employed, instead of the one-loop pole mass used in the previous analyses. The light-cone sum rule for $f^+_{Bπ}(q^2)$ is fitted to the measured $q^2$-distribution in $B\to πl ν_l$, fixing the input parameters with the largest uncertainty: the Gegenbauer moments of the pion distribution amplitude. For the $B\to π$ vector form factor at zero momentum transfer we predict $f^+_{Bπ}(0)= 0.26^{+0.04}_{-0.03}$. Combining it with the value of the product $|V_{ub}f^+_{Bπ}(0)|$ extracted from experiment, we obtain $|V_{ub}|=(3.5\pm 0.4\pm 0.2\pm 0.1) \times 10^{-3}$. In addition, the scalar and penguin $B\to π$ form factors $f^0_{Bπ}(q^2)$ and $f^T_{Bπ}(q^2)$ are calculated.
Light Cone Sum Rules for the pi0-gamma*-gamma Form Factor Revisited
我们提供了一个理论更新的计算的π 0-γ *-γ形状因子的LCSR框架中，包括多达六个多项式的π分布振幅的保形展开，并考虑到扭曲六校正相关的光子发射在大的距离。并将计算结果与在同一框架下的B-> pi l nu衰变和π介子电磁形状因子的计算结果进行了比较。我们的结论是，最近BaBar测量的π 0-γ *-γ形状因子在大动量转移是一致的QCD，虽然他们确实表明，π DA可能有更多的结构比通常假设。
We outline the developed approach within the light-cone sum rules at the leading order for calculation of the gravitational form factors related to the nucleon valence quark combinations. The predictions for the gravitational form factor $D(t)$ ($D$-term contributions) have been presented.
The tensor form factors of $B$ into p--wave axial vector meson transition are calculated within light cone QCD sum rules method. The parametrizations of the tensor form factors based on the series expansion are presented.
Recently, LHCb Collaboration announced the discovery of radial excitations of $D_s$ and $B_s$ mesons. In present work, we calculate the most promising strong and electromagnetic decay widths of radially excited $D_s(2S)$ and $B_s(2S)$ mesons within the light cone QCD sum rules method.
In this article, we study the $B \to K^*_2(1430)$, $a_2(1320)$, $f_2(1270)$ form-factors with the light-cone QCD sum rules, where the $B$-meson light-cone distribution amplitudes are used. In calculations, we observe that the line-shapes of the $B$-meson light-cone distribution amplitude $ϕ_+(ω)$ have significant impacts on the values of the form-factors, and expect to obtain severe constraints on the parameters of the $B$-meson light-cone distribution amplitudes from the experimental data in the future.
Strong decay constants of the heavy tensor to heavy pseudoscalar (vector) and light pseudoscalar mesons are estimated within the light cone QCD sum rules. It is obtained that the values of these coupling constants are very strongly dependent on the choice of the Lorentz structure. Moreover, using these strong coupling constants the corresponding decay widths are calculated.
The magnetic moments of heavy sextet $J^P = {1\over 2}^+$ baryons are calculated in framework of the light cone QCD sum rules method. Linearly independent relations among the magnetic moments of these baryons are obtained. The results for the magnetic moments of heavy baryons obtained in this work are compared with the predictions of the other approaches.
We complete the set of QCD light-cone sum rules for $B\to ππ$ transition form factors, deriving a new sum rule for the timelike-helicity form factor $F_t$ in terms of dipion distribution amplitudes. This sum rule, in the leading twist-2 approximation, is directly related to the pion vector form factor. Employing a relation between $F_t$ and other $B\to ππ$ form factors we obtain also the longitudinal-helicity form factor $F_0$. In this way, all four (axial-)vector $B\to ππ$ form factors are predicted from light-cone sum rules with dipion distribution amplitudes. These results are valid for sma…
