B → η′ + X and the QCD anomaly

Abstract

Mechanisms for the observed large Br(B → η ′ + X s ) are examined. We propose that the dominant fraction of the B → η ′ + X s rate is due mainly to b → sg * , where g * is an off-shell gluon, followed by g * → gη ′ via the anomalous coupling of the η ′ to two gluons. The calculated rate for B → η ′ + X s is in rough accord with experiment using a fairly constant glueglue-η ′ form factor. This behavior of the form factor may be indicative of glueball dominance of the channel. Searches via the modes η ′ h + h − (h = π or K) may be worthwhile. Charmonia contributions [i.e B → η c , ψ(→ η ′ + X) + X s ] can only account for at most 20% of the central value of the signal. Implications for B → η ′ +X d and for the corresponding η modes are also given. IntroductionRecently CLEO has reported[1] a very large branching ratio for the inclusive production of η ′ (subject to the indicated cut):In this Letter we report on possible mechanisms for this large signal. Two interesting origins are: (1) b → s + g * (where g * is an off-shell gluon) followed by g * → η ′ + g due to the anomalous η ′ -g-g vertex. (2) b → charmonia (e.g. ψ, η c ) + X s followed by ψ(η c ) → η ′ + X. We discuss these below in turn.

Charmless three-body baryonicBdecays

“…The underlying dynamics could be g * → gξ, which is analogous to g * → gη ′ for B → η ′ + X s decay [27]. One should also search in three-body mesonic decay modes.…”

Flavor violation in warped extra dimensions and CP asymmetries in B decays

“…(11). In addition to this source of uncertainty, it is generally expected that this decay mode would receive an enhancement from the large coupling of the QCD anomaly [22] to the singlet piece in η ′ . Several attempts have been made to estimate the size of this effect, suggested first by the large branching fractions with η ′ in the final states.…”

Penguins, Charmless B Decays and the Hunt for CP Violation

“…Factorization and Anomaly Shuryak & Zhitnitsky [7] η [9] η ′ Xs New Physics Kagan & Petrov [5] η ′ Xs New Physics Yuan & Chao [10] η ′ Xs (cc)8 → η ′ Xs Datta et al [6] η ′ Xs Factorization + Anomaly Atwood & S [11] η ′ Xs, ηXs · · · QCD Anomaly…”