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Title: Model-independent analysis of B → πℓ{sup +}ℓ{sup −} decays

The results obtained by calculating, on the basis of the Standard Model, the branching fractions for the decays B → πℓ{sup +}ℓ{sup −} (ℓ{sup ±} = e{sup ±}, µ{sup ±}) and the invariant-mass spectrum of dileptons for the process B{sup +} → π{sup +}ℓ{sup +}ℓ{sup −} are presented. The resulting theoretical estimates depend on the choice of model for the B → π transition form factors f{sub +}(q{sup 2}), f{sub 0}(q{sup 2}), and f{sub T} (q{sup 2}). However, one can get rid of this arbitrariness by employing experimental data or the results of QCD lattice calculations to determine the parameter dependence of the form factors. Data from B-meson factories were used to determine the dependence of the form factor f{sub +}(q{sup 2}) on the transfer momentum squared. Yet another required form factor, f{sub T} (q{sup 2}), was extracted from available lattice data on B → π and B → K transitions with allowance for nearly identical effects of the breakdown of flavor SU(3){sub F} symmetry in the respective form factors. The resulting value of the decay branching fraction, B(B{sup +} → π{sup +}µ{sup +}µ{sup −}) = (1.88{sub −0.21}{sup +0.32}) × 10{sup −8}, is in good agreement with the results ofmore » measurements of the LHCb Collaboration. The branching fraction for the isospin analog of the decay under consideration is B(B{sup +} → π{sup +}µ{sup +}µ{sup −}) = (0.94{sub −0.11}{sup +0.16}) × 10{sup −8}. Therefore, this decay can be measured at the Super-B factory under construction.« less
Authors:
 [1] ; ;  [2]
  1. Deutsches Elektronen-Synchrotron DESY, Theory Group (Germany)
  2. Demidov Yaroslavl State University, Department of Theoretical Physics (Russian Federation)
Publication Date:
OSTI Identifier:
22472288
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Atomic Nuclei; Journal Volume: 78; Journal Issue: 3; Other Information: Copyright (c) 2015 Pleiades Publishing, Ltd.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; B MESONS; BRANCHING RATIO; ELECTRONS; FLAVOR MODEL; FORM FACTORS; ISOSPIN; MASS SPECTRA; MESON FACTORIES; MOMENTUM TRANSFER; PARTICLE DECAY; PIONS; POSITRONS; QUANTUM CHROMODYNAMICS; STANDARD MODEL; SU-3 GROUPS; SYMMETRY