journal6 ›› 2002, Vol. 23 ›› Issue (3): 66-72.

• Physics and electronics • Previous Articles     Next Articles

The Calculation of B→π Transitions Form Factor


  1. (1.Department of Physics,Huaibei Coal Mining Teachers College,Huaibei 235000,Anhui China;2.Institute of High Energy Physics,Chinese Academy of Sciences,Beijing 100039,China)
  • Online:2002-09-15 Published:2013-01-05

Abstract: The heavy-to-light transition form factors are very important parameters,which play an important role in B-meson decays. The uncertainties of calculation of form factors in light-cone QCD sum rules mainly come from light-cone wave function among which twist-2 and twist-3 wave function make significant contributions to form factors. Now only twist-2 wave function has been systematically analyzed and twist-3 and twist-4 wave function have not satisfactorily determined but twist-4 contribution is very small, therefore, it is twist-3 wave function that cause large uncertainty of form factors. So, through construction adequate chiral current correlation function and consideration of all twist 2 and 4 contribution, the heavy-to-light B→π transitions form factor was calculated in improved light-cone QCD sum rules, and was compared with the result in standard light-cone QCD sum rules. They are consistent with each other, but the uncertainties are eliminated about twist-3 wave function, so the CKM matrix element |Vub| precisely can be extracted.The contributions of every parameter to uncertainties of calculation result f(q2) are discussed and presented. For example, the contributions of Borel parameter is ±(3~5)%; light-cone wave function ±10%; The higher twist wave functions are less than 5%.


Key words: improved light-cone QCD sum rules, form factor, CKM matrix element

WeChat e-book chaoxing Mobile QQ