Implications of Isospin Conservation in ${\Lambda }_b$ Decays and Lifetime

Abstract

We consider isospin predictions for the semi-leptonic and non-leptonic decays of the ${\Lambda }_b$ baryon. Isospin conservation of the strong interactions constrains the possible final states in ${\Lambda }_b$ decays. Since the baryon hyperfine splittings depend upon light quark dynamics and do not decrease with increasing heavy quark mass, this leads in general to to phase space enhancements in ${\Lambda }_b$ decays relative to $B$ meson decays for the same underlying quark transitions. Consequently the ${\Lambda }_b$ lifetime is smaller than the $B$ lifetime. Phase space enhancements in ${\Lambda }_b$ decays relative to $B$ decays can be understood in terms of hyperfine interactions in the heavy quark system.

Changes in abstract and introduction. To appear in Phys.Lett. B. Latex 12 pages, no figures

References in corpus (4)

• Aspects Of Heavy Quark Theory
• Heavy Baryon Transitions in a Relativistic Three-Quark Model
• Calculation of the semileptonic decay width of the ${\Lambda }_b$ baryon
• Hyperfine Interactions in Charm and Bottom Systems

Cited by in corpus (6)

• T-Violating Triple-Product Correlations in Charmless Lambda_b Decays
• Electromagnetic Transitions of Heavy Baryons in the SU(2N_{f}) X O(3) Symmetry
• Nonleptonic ${\Lambda }_b$ decays to $D_s(2317)$, $D_s(2460)$ and other final states in Factorization
• Reanalysis of the Four-Quark Operators Relevant to Λ_b Lifetime from QCD Sum Rule
• Observation of ${\Lambda }_b^0\to {\Lambda }_c^{+}{\bar{D}}^{(\ast )0}{K}^{-}$ and ${\Lambda }_b^0\to {\Lambda }_c^{+}{D}_s^{\ast -}$ decays
• T-odd Observables in Elastic Scattering, in Deep Inelastic Processes and in Weak Decays