Isospin in $B$ Decays and the $(B^0{\bar{B}}^0)/(B^{+}{B}^{-})$ Production Ratio

Abstract

Methods are proposed for measuring the ratio $R^{+/0}=\Gamma ({\rm Y}(4S)\to B^{+}{B}^{-})/$ $Γ(Υ(4S) \to \bo \ob)$ without assuming isospin invariance in exclusive hadronic decays such as $B\to J/\psi K$. The validity of isospin invariance in various B decays is discussed. Isospin violations are expected to be especially small in inclusive semileptonic decays, so that $\Gamma (B^{+}\to X_c^0{\ell }^{+}{\nu }_{\ell })=\Gamma (B^0\to X_c^{-}{\ell }^{+}{\nu }_{\ell })$ is expected to hold at the sub-percent level. Suggestions are made for utilizing this relation. The accuracy of a ``double-tag'' method for obtaining $R^{+/0}$, such as that used for measuring the $D^+ D^-/D^0 \od$ ratio at the ${\psi }^{\prime \prime }\equiv \psi (3770)$, is also estimated.

arXiv comment6 pages, no figures, to be published in Phys. Rev. D (Brief Reports). One reference and acknowledgment added; slight text change

References in corpus (13)

• Symmetry-breaking corrections to heavy-to-light B meson form factors at large recoil
• Factorization and Endpoint Singularities in Heavy-to-Light decays
• Measurement of Absolute Hadronic Branching Fractions of D Mesons and e^+e^- --> D barD Cross Sections at E_cm = 3773 MeV
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• Variation of the relative yield of charged and neutral B mesons across the Upsilon(4S) resonance
• Isospin violation in e+ e- --> B Bbar
• Measurement of the Branching Fraction of Upsilon(4S) --> B0B0bar
• Measurement of the Ratio of Branching Fractions of the Upsilon(4S) to Charged and Neutral B Mesons
• Experimental Limits on Weak Annihilation Contributions to b -->u ell nu Decay
• Isotopic splittings and OPE in B -> D semileptonic decays
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Cited by in corpus (3)

• Branching ratio measurements and isospin violation in B-meson decays
• Measurement of the Ratio of Partial Branching Fractions of Inclusive $\overline{B}\to X_u\ell \overline{\nu }$ to $\overline{B}\to X_c\ell \overline{\nu }$ and the Ratio of their Spectra with Hadronic Tagging
• Precision Tests of Flavor and CP violation in B Decays