Is right-handed current contribution to $\bar{B}\to X_{u}l\nu$ decays corrected by non-trivial vacuum in QCD?

Abstract

We study violation of quark-hadron duality for $\bar{B}\to X_{u}l\nu$ and $D\to X_{d}l\nu$ decays in the presence of the right-handed current operator. For this case, we show that duality violation has some aspects different from the standard model due to the existence of an instanton. In particular, the fermionic zero mode of an intermediate light quark can give a nonvanishing contribution owing to its chirality structure. A duality-violating component that arises from a single instanton is then analytically extracted as a finite-distance singularity, leading to an oscillatory correction to the observable in Minkowski space. Finally, we show that the size of duality violation for the lepton energy distribution in $\bar{B}$ decays can be comparable to the chirally suppressed perturbative contribution although the absolute size depends on the detail of the QCD vacuum.

19 pages, 2 figures, 2 tables; v3: matches the version published in PRD

References in corpus (8)

• Can the differences in the determinations of $V_{ub}$ and $V_{cb}$ be explained by New Physics?
• Inclusive semi-leptonic decays from lattice QCD
• Lattice QCD study of inclusive semileptonic decays of heavy mesons
• Complete Michel Parameter Analysis of inclusive semileptonic b \to c transition
• Testing the left-handedness of the b \to c transition
• Heavy meson semileptonic differential decay rate in two dimensions in the large Nc
• Quark-hadron duality for heavy meson mixings in the 't Hooft model
• Revisiting quark-hadron duality for heavy meson non-leptonic decays in two-dimensional QCD

Cited by in corpus (3)

• Quark-hadron duality at work: lifetimes of bottom baryons
• First Simultaneous Determination of Inclusive and Exclusive $\left|V_{ub}\right|$
• $B\to X_c\ell \bar{\nu }$ Decay as a Probe of Complex Conjugate Poles