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

## Abstract

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 »

- Authors:

- Deutsches Elektronen-Synchrotron DESY, Theory Group (Germany)
- Demidov Yaroslavl State University, Department of Theoretical Physics (Russian Federation)

- Publication Date:

- OSTI Identifier:
- 22472288

- Resource Type:
- Journal Article

- Journal Name:
- Physics of Atomic Nuclei

- Additional Journal Information:
- Journal Volume: 78; Journal Issue: 3; Other Information: Copyright (c) 2015 Pleiades Publishing, Ltd.; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1063-7788

- 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

### Citation Formats

```
Ali, A., E-mail: ahmed.ali@desy.de, Parkhomenko, A. Ya., E-mail: parkh@uniyar.ac.ru, and Rusov, A. V., E-mail: rusov@uniyar.ac.ru.
```*Model-independent analysis of B → πℓ{sup +}ℓ{sup −} decays*. United States: N. p., 2015.
Web. doi:10.1134/S1063778815020064.

```
Ali, A., E-mail: ahmed.ali@desy.de, Parkhomenko, A. Ya., E-mail: parkh@uniyar.ac.ru, & Rusov, A. V., E-mail: rusov@uniyar.ac.ru.
```*Model-independent analysis of B → πℓ{sup +}ℓ{sup −} decays*. United States. doi:10.1134/S1063778815020064.

```
Ali, A., E-mail: ahmed.ali@desy.de, Parkhomenko, A. Ya., E-mail: parkh@uniyar.ac.ru, and Rusov, A. V., E-mail: rusov@uniyar.ac.ru. Fri .
"Model-independent analysis of B → πℓ{sup +}ℓ{sup −} decays". United States. doi:10.1134/S1063778815020064.
```

```
@article{osti_22472288,
```

title = {Model-independent analysis of B → πℓ{sup +}ℓ{sup −} decays},

author = {Ali, A., E-mail: ahmed.ali@desy.de and Parkhomenko, A. Ya., E-mail: parkh@uniyar.ac.ru and Rusov, A. V., E-mail: rusov@uniyar.ac.ru},

abstractNote = {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 of 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.},

doi = {10.1134/S1063778815020064},

journal = {Physics of Atomic Nuclei},

issn = {1063-7788},

number = 3,

volume = 78,

place = {United States},

year = {2015},

month = {5}

}