Weak Decays of Excited B Mesons

Area of Science:

• Particle Physics
• High Energy Physics
• Quantum Chromodynamics

Background:

• Excited heavy quark mesons (bq[over ¯]) are unstable, with widths suppressed by phase space.
• Vector B* mesons offer unique probes of weak transitions, unlike pseudoscalar B mesons.
• Their purely leptonic decays are not chirally suppressed, probing different weak effective operators.

Purpose of the Study:

• To investigate the decays of excited (bq[over ¯]) mesons.
• To utilize these decays as probes of the short-distance structure of weak ΔB=1 transitions.
• To explore the potential of measuring B*→ℓℓ amplitudes via scattering experiments.

Main Methods:

• Theoretical analysis of excited (bq[over ¯]) meson decays.
• Standard Model predictions for decay rates.
• Discussion of experimental prospects at the Large Hadron Collider (LHC).

Main Results:

• The decay B_{s}^{*}→ℓ^{+}ℓ^{-} has a predictable rate in the Standard Model, with a branching fraction around 10^{-11}.
• Uncertainty in the branching fraction is dominated by the poorly known B_{s}^{*} width.
• Measuring the B_{s}^{*}→ℓℓ amplitude via scattering is a viable alternative.

Conclusions:

• Excited heavy quark meson decays provide valuable insights into fundamental particle interactions.
• The B_{s}^{*}→ℓ^{+}ℓ^{-} decay is a promising channel for Standard Model tests.
• Future experiments at the LHC and resonance scattering offer pathways to further investigate these phenomena.