B→Kη′decay as a unique probe of theη′meson

Abstract

A theory of the B → Kη ′ decay is proposed. It is based on the Cabbibo favored b → ccs process followed by a direct materialization of the cc pair into the η ′ . This mechanism works due to a non-valence Zweig rule violating c-quark component of the η ′ , which is unique to its very special nature. This non-perturbative "intrinsic charm" content of the η ′ is evaluated using the Operator Product Expansion and QCD low energy theorems. Our results are consistent with an unexpectedly large Br(B → Kη ′ ) ≃ 7.8 • 10 −5 recently announced by CLEO.

Bmeson decays to charmless meson pairs containingηorη′mesons

“…The measured 0 K branching fraction is found to be much larger than the K one [2,3]. Many suggestions have been proposed to explain such a difference, including flavor singlet enhancement [12], intrinsic charm [13], and constructively interfering internal penguin diagrams [14,15]. This last approach is supported by nextto-leading order QCD factorization calculations [6].…”

B→η(′)(l−ν¯l,lAkeroyd1, Chen2, Geng3 2007Phys. Rev. D362370View full textAdd to dashboardCite

“…2 −0.1 ) × 10 −6 [3], BR(B + → η ′ K + ) = (69.2 ± 2.2 ± 3.7) × 10 −6 and BR(B 0 → η ′ K 0 ) = (58.9 +3.6 −3.5 ± 4.3) × 10 −6 [4], while the latter has measured BR(B + → ηK + ) = (3.3 ± 0.6 ± 0.3) × 10 −6 [5], BR(B + → η ′ K + ) = (68.9±2.0±3.2)×10 −6 and BR(B 0 → η ′ K 0 ) = (67.4±3.3±3.2)×10 −6 [6]. To unravel the mystery, many solutions have been proposed, such as the intrinsic charm in η ′ [7], the gluonium state [8], the spectator hard scattering mechanism [9] and the flavorsinglet component in η ′ [10]. Nevertheless, there are still no conclusive solutions yet.…”

Exclusive charmless Bs hadronic decays into η′ and η

“…If N eff c is process independent, then we have a generalized factorization. In this paper, we will treat the nonfactorizable contributions with two different phenomenological ways : (i) the one with "homogenous" structure, which assumes 10 , and (ii) the "heterogeneous" one, which considers the possibility of N eff c (V + A) = N eff c (V − A). The consideration of the "homogenous" nonfactorizable contributions, which is commonly used in the literature, has its advantage of simplicity.…”

“…This new internal W -emission contribution will be important when the mixing angle involved is V cb V * cs , which is as large as that of the penguin amplitude and yet its effective parameter a eff 2 is larger than that of penguin operators. The decay constant f (cc) η ′ , defined as 0|cγ µ γ 5 c|η ′ = if (cc) η ′ q µ , has been determined from the theoretical calculations [10,11,12] and from the phenomenological analysis of the data of J/ψ → η c γ, J/ψ → η ′ γ and of the ηγ and η ′ γ transition form factors [9,13]. In the presence of the charm content in the η 0 , an additional mixing angle θ c is needed to be introduced:…”

“…First, the QCD anomaly does occur through the equation of motion [8,9] when calculating the (S − P )(S + P ) penguin operator and its effect is found to reduce the branching ratio. Second, the mechanism of cc → η ′ , although proposed to be large and positive originally [10,11], is now preferred to be negative and smaller than before as implied by a recent theoretical recalculation [12] and several phenomenological analyses [9,13]. Third, the running strange quark mass which appears in the calculation of the matrix elements of the (S − P )(S + P ) penguin operator, the SU(3) breaking effect in the involved η ′ decay constants and the normalization of the B → η ( ′ ) matrix element involved raise the branching ratio substantially.…”