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Title: B{yields}{pi}l{nu}{sub l} width and |V{sub ub}| from QCD light-cone sum rules

Journal Article · · Physical Review. D, Particles Fields
; ;  [1];  [2]
  1. Theoretische Physik 1, Physik Department, Universitaet Siegen, D-57068, Siegen (Germany)
  2. Institut fuer Theoretische Physik, Universitaet Regensburg, D-93040, Regensburg (Germany)

We employ the B{yields}{pi} form factors obtained from QCD light-cone sum rules and calculate the B{yields}{pi}l{nu}{sub l} width (l=e, {mu}) in units of 1/|V{sub ub}|{sup 2}, integrated over the region of accessible momentum transfers, 0{<=}q{sup 2{<=}}12.0 GeV{sup 2}. Using the most recent BABAR Collaboration measurements we extract |V{sub ub}|=(3.50{sub -0.33}{sup +0.38}|{sub th{+-}}0.11|{sub exp})x10{sup -3}. The sum rule results for the form factors, taken as an input for a z-series parametrization, yield the q{sup 2} shape in the whole semileptonic region of B{yields}{pi}l{nu}{sub l}. We also present the charged lepton energy spectrum in this decay. Furthermore, the current situation with B{yields}{tau}{nu}{sub {tau}} is discussed from the QCD point of view. We suggest using the ratio of the B{yields}{pi}{tau}{nu}{sub {tau}} and B{yields}{pi}l{nu}{sub l}(l={mu},e) widths as an additional test of the standard model. The sensitivity of this observable to new physics is illustrated by including a charged Higgs-boson contribution in the semileptonic decay amplitude.

OSTI ID:
21541618
Journal Information:
Physical Review. D, Particles Fields, Vol. 83, Issue 9; Other Information: DOI: 10.1103/PhysRevD.83.094031; (c) 2011 American Institute of Physics; ISSN 0556-2821
Country of Publication:
United States
Language:
English