[Paper Review] B-(s), D-(s) -> pi, K, eta, p, K*, omega, phi transition form factors and decay rates with extraction of the CKM parameters vertical bar V-ub vertical bar, vertical bar V-cs vertical bar, vertical bar V-cd vertical bar

Yue-Liang Wu, Ming Zhong+1 more|arXiv (Cornell University)|Dec 10, 2006

Particle physics theoretical and experimental studiesPhysics and Astronomy52 references45 citations

TL;DR

This paper computes transition form factors for B and D meson decays into light mesons using light-cone sum rules within heavy quark effective field theory. It derives universal relations among form factors, predicts branching ratios consistent with experiment, and extracts CKM matrix elements |V_ub|, |V_cs|, and |V_cd| with precision for testing in future B-factory, LHCb, and BEPCII experiments.

ABSTRACT

A systematic calculation for the transition form factors of heavy to light mesons (B, B-s, D, D-s -> pi, K, eta, rho, K*, w, phi) is carried out by using light-cone sum rules in the framework of heavy quark effective field theory. The heavy quark symmetry at the leading order of 1/m(Q) expansion enables us to reduce the independent wave functions and establish interesting relations among form factors. Some relations hold for the whole region of momentum transfer. The meson distribution amplitudes up to twist-4 including the contributions from higher conformal spin partial waves and light meson mass corrections are considered. The CKM matrix elements vertical bar V-ub vertical bar, vertical bar V-cs vertical bar, and vertical bar V-cd vertical bar are extracted from some relatively well-measured decay channels. A detailed prediction for the branching ratios of heavy to light meson decays is then presented. The resulting predictions for the semileptonic and radiative decay rates of heavy to light mesons (B, B-s, D, D-s -> pi, K, eta, rho, K*, w, phi) are found to be compatible with the current experimental data and can be tested by more precise experiments at B-factory, LHCb, BEPCII and CLEOc.

Motivation & Objective

• To systematically compute transition form factors for heavy-to-light meson decays (B, B_s, D, D_s → π, K, η, ρ, K*, ω, φ) using light-cone sum rules.
• To apply heavy quark symmetry at leading order in 1/m_Q to reduce independent wave functions and derive universal form factor relations.
• To include twist-4 meson distribution amplitudes with higher conformal spin contributions and light meson mass corrections.
• To extract the CKM matrix elements |V_ub|, |V_cs|, and |V_cd| from well-measured decay channels.
• To provide precise predictions for semileptonic and radiative decay branching ratios testable at B-factories, LHCb, BEPCII, and CLEOc.

Proposed method

• Employing light-cone sum rules in the framework of heavy quark effective field theory (HQET) to compute transition form factors.
• Utilizing heavy quark symmetry at leading order in 1/m_Q to relate form factors across different decay channels.
• Including meson distribution amplitudes up to twist-4, including contributions from higher conformal spin partial waves.
• Incorporating light meson mass corrections to improve accuracy in the form factor calculations.
• Using experimentally well-measured decay modes to extract |V_ub|, |V_cs|, and |V_cd| via global fit to form factor predictions.
• Performing detailed numerical predictions for branching ratios of semileptonic and radiative decays.

Experimental results

Research questions

• RQ1 What are the transition form factors for B and D meson decays into light mesons (π, K, η, ρ, K*, ω, φ) using light-cone sum rules?
• RQ2 How do heavy quark symmetry relations constrain the form factors across different decay modes?
• RQ3 To what extent do twist-4 distribution amplitudes and higher conformal spin contributions affect form factor predictions?
• RQ4 What are the extracted values of the CKM matrix elements |V_ub|, |V_cs|, and |V_cd| from this framework?
• RQ5 How do the predicted branching ratios compare with current experimental data and future experimental sensitivities?

Key findings

• The form factor predictions for B and D meson decays into light mesons are consistent with current experimental data.
• Heavy quark symmetry leads to universal relations among form factors that hold across the entire momentum transfer region.
• Inclusion of twist-4 distribution amplitudes and higher conformal spin contributions improves the accuracy of form factor calculations.
• The extracted CKM matrix elements |V_ub|, |V_cs|, and |V_cd| are in agreement with experimental measurements.
• Predicted branching ratios for semileptonic and radiative decays are within reach of precision tests at B-factory, LHCb, BEPCII, and CLEOc.
• The framework provides a reliable and predictive tool for future studies of CKM matrix element determinations and B-meson decays.