Beyond the standard model in B decays: Three topics

Abstract

Three new results are discussed: (a) A non-vanishing amplitude for the 'wrong sign' kaon decay B → J/ΨK or its CP conjugate is shown to be a necessary condition for obtaining different CP asymmetries in B → J/ΨK S,L . A significant effect would require a scale of new physics far below the weak scale, all but ruling out this possibility. (b) The leading isospin breaking contributions to the B → K * γ decay amplitudes can be calculated in QCD factorization, providing a sensitive probe of the penguin sector of the effective weak Hamiltonian. New physics models which reverse the predicted 10 − 20% Standard Model amplitude hierarchy could be ruled out with more precise data. (c) A slowly falling g * g η ′ form factor can be ruled out using the η ′ spectrum obtained by ARGUS at the ϒ(1S). The decay b → sgη ′ is therefore highly suppressed and the origin of the anomalously large B → η ′ X s rate remains unknown, perhaps requiring the intervention of New Physics.

Probing gluons in nuclei: The case ofη′

“…Assuming that we understand the parton distributions in a proton, pA experiments are an excellent tool with which to investigate parton distributions of nuclei at small x. This becomes even more important in light of the fact that not much is known about modification of parton distributions in nuclei at small 1 This weak dependence assumption has been questioned by Kagan and Petrov [4] who argued that when one of the gluon momenta is off-shell, the form factor has to be replaced by…”

An analysis of the inclusive decay $\Upsilon (1S) \to \eta^\prime X$ and constraints on the $\eta^\prime$ -meson distribution amplitudes

“…In this paper, we undertake a perturbative-QCD based analysis of the recent data on the inclusive process Υ(1S) → η X in the large η -meson energy region published recently by the CLEO collaboration [35], which is expected to be dominated by the process Υ(1S) → η ggg → η X. Moreover, Chen and Kagan [22] have argued that the shape of the η -meson energy spectrum in this decay is sensitive to the shape of the F η g * g (q 2 , 0, m 2 η ) vertex function, involving the η -meson, a real and a virtual gluons (see Fig. 1).…”

“…3 is calculated with the same set of phenomenological parameters as has been used in Ref. [22] for the following three input forms 3 :…”

“…This implies that for processes involving gluons and the η -meson, in particular in the decays of heavy mesons of current phenomenological interest, such as b → sgη inducing the B → η X s decay [7][8][9][10][11][12][13] and the exclusive B → (η, η )(K, K * ) decays [14][15][16][17][18][19][20][21], but also the inclusive decay of the Orthoquarkonium Υ(1S) → gg(g * → η g) → η X [22], the effective η -gluon-gluon vertex plays an important role. This effective vertex function (EFV) has to be known sufficiently well to undertake a quantitative analysis of data involving the η -meson.…”

Production ofη′from thermal gluon fusion

“…Recently, there was a surge of interest in η ′ in the study of B-meson decays and search for new physics [6,7,8,9,10]. In some of these studies, the axial anomaly relation…”