Three-loop perturbative corrections to B and D meson lifetime ratios are calculated, producing values that agree with experiment when using HQET sum rules or lattice inputs.
Spectator Effects in Inclusive Decays of Beauty Hadrons
5 Pith papers cite this work. Polarity classification is still indexing.
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abstract
We present a model-independent study of spectator effects, which are responsible for the lifetime differences between beauty hadrons. These effects can be parametrized in terms of hadronic matrix elements of four four-quark operators. For $B$ mesons, the coefficients of the non-factorizable operators turn out to be much larger than those of the factorizable ones, limiting considerably the usefulness of the vacuum insertion approximation. Non-factorizable contributions to the lifetime ratio $\tau(B^-)/\tau(B_d)$ could naturally be of order 10--20%, and not even the sign of these contributions can be predicted at present. In the case of the $\Lambda_b$ baryon, heavy-quark symmetry is used to reduce the number of independent matrix elements from four to two. In order to explain the large deviation from unity in the experimental result for $\tau(\Lambda_b)/\tau(B_d)$, it is necessary that these baryon matrix elements be much larger than those estimated in quark models. We have also reexamined the theoretical predictions for the semileptonic branching ratio of $B$ mesons and charm counting, finding that, given the present theoretical and experimental uncertainties, there is no significant discrepancy with experiment.
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hep-ph 5representative citing papers
Complete NLO QCD corrections to charmless inclusive non-leptonic B-decay widths are computed for the full BSM operator set, yielding 26 constrained directions in Wilson coefficient space.
NNLO-QCD corrections to the free b-quark decay and NLO corrections to dimension-five operators reduce uncertainties in HQE predictions for b-baryon lifetimes, yielding excellent agreement with experiment.
Updated predictions within the heavy quark expansion confirm the lifetime hierarchy τ(Ξ_cc^+) < τ(Ω_cc^+) < τ(Ξ_cc^++) with τ(Ξ_cc^++) = 0.32 ± 0.05 +0.08/-0.07 ps matching LHCb data and provide ratios for the other states.
citing papers explorer
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Next-to-next-to-leading QCD corrections to the $\mathbf{B^+}$-$\mathbf{B_d^0}$, $\mathbf{D^+}$-$\mathbf{D^0}$, and $\mathbf{D_s^+}$-$\mathbf{D^0}$ lifetime ratios
Three-loop perturbative corrections to B and D meson lifetime ratios are calculated, producing values that agree with experiment when using HQET sum rules or lattice inputs.
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Inclusive Charmless Non-Leptonic B Decays at NLO within and beyond the Standard Model
Complete NLO QCD corrections to charmless inclusive non-leptonic B-decay widths are computed for the full BSM operator set, yielding 26 constrained directions in Wilson coefficient space.
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Predictions for $b$-baryon lifetimes at NNLO-QCD
NNLO-QCD corrections to the free b-quark decay and NLO corrections to dimension-five operators reduce uncertainties in HQE predictions for b-baryon lifetimes, yielding excellent agreement with experiment.
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Revisiting lifetimes of doubly charmed baryons
Updated predictions within the heavy quark expansion confirm the lifetime hierarchy τ(Ξ_cc^+) < τ(Ω_cc^+) < τ(Ξ_cc^++) with τ(Ξ_cc^++) = 0.32 ± 0.05 +0.08/-0.07 ps matching LHCb data and provide ratios for the other states.
- Study of doubly heavy baryon lifetimes