Physics of B_c-mesons

Abstract

Gershtein S.S., Kiselev V.V., Likhoded A.K., Tkabladze A.V. Physics of B c mesons: IHEP Preprint 94-81. -Protvino, 1994. -p. 82, figs. 23, tables 28. In the framework of potential models for heavy quarkonium the mass spectrum for the system (bc) is considered. Spin-dependent splittings, taking into account a change of a constant for effective coulomb interaction between the quarks, and widths of radiative transitions between the (bc) levels are calculated. In the framework of QCD sum rules, masses of the lightest vector B * c and pseudoscalar B c states are estimated, scaling relation for leptonic constants of heavy quarkonia is derived, and the leptonic constant f Bc is evaluated. The B c decays are considered in the framework of both the potential models and the QCD sum rules, where the significance of Coulomb-like corrections is shown. The relations, following from the approximate spin symmetry for the heavy quarks in the heavy quarkonium, are analysed for the form factors of the semileptonic weak exclusive decays of B c . The B c lifetime is evaluated with the account of the corrections to the spectator mechanism of the decay, because of the quark binding into the meson. The total and differential cross sections of the B c production in different interactions are calculated. The analytic expressions for the fragmentational production cross sections of B c are derived. The possibility of the practical B c search in the current and planning experiments at electron-positron and hadron colliders is analysed.

Hadrons with charm and beauty

“…These are the values also obtained by Gershtein et al [16], who used essentially the same potential. Previously, Eichten and Feinberg, in the course of their study of spin-dependent forces [2], considered the (bc) system, and got…”

“…The error in this result comes from the departures of different potential-model predictions [16], [19], [17] from our value. It will be compared in section 3 with the QSSR estimates.…”

Is X(3872) really a molecular state?

“…Later, we performed a detailed study of this state in the molecular picture [46]. A short review of the current theoretical status of Z + (4430) [43,44,47,48,49,50,51,52,53,54,55] was also given in Ref. [45].…”

Effects of coupled channels on cb̄ masses and decays in NRQM with OGEP

“…The M1 decay widths for allowed transitions (n 3 S 1 → n ′1 S 0 + γ, n = n ′ ) have been calculated and are compared with other non relativistic quark models [33,41,43]. The decay widths of hindered transitions(n = n ′ ) are zero in the non relativistic limit due to the orthogonality of the initial and final state wave functions.…”