Mass spectrum and leptonic decay constants of ground and radially excited states of η_c and η_b in a Bethe–Salpeter equation framework

Abstract

In this paper, we study the mass spectrum and decay constants of ground state (1S) and radially excited states (2S and 3S) of heavy equal mass pseudoscalar mesons, ηc and ηb. We have employed the framework of Bethe–Salpeter equation (BSE) under Covariant Instantaneous Ansatz (CIA). Our predictions are in reasonable agreement with the data on available states and results of other models.

Radiative Decay Widths of Ground and Excited States of Vector Charmonium and Bottomonium

“…The projected wave functions, ±± (̂), in Salpeter equations are obtained by the operation of the above projection operators on (̂) (for details see [20,21]) as…”

“…In a recent work [20,21], we employed a 4 × 4 representation for two-body ( ) BS amplitude for calculating both the mass spectra and the transition amplitudes for various processes. However, the price one pays in this approach is to solve a coupled set of Salpeter equations for both pseudoscalar and vector quarkonia.…”

Charmonium Properties Using the Discrete Variable Representation (DVR) Method

“…Theoretically, quarkonium systems have been studied by various formalisms based on phenomenological potential models [7][8][9][10][11], effective field theory [12], lattice gauge theory [13][14][15][16], Bethe Salpeter equation [17][18][19][20], etc. Among these, owing to its simplicity, formalism based on potential models is the widely chosen method to investigate quarkonium sys-tems.…”

Charmonium Properties Using the Discrete Variable Representation (DVR) Method

“…Studies on heavy quark systems are important because it gives information about quark interaction potential, confinement, QCD coupling constant, CKM matrix elements, and various other inputs to the standard model, some of which cannot be directly obtained from QCD. Theoretically, quarkonium systems have been studied by various formalisms based on phenomenological potential models [7][8][9][10][11], effective field theory [12], lattice gauge theory [13][14][15][16], Bethe Salpeter equation [17][18][19][20], etc. Among these, owing to its simplicity, formalism based on potential models is the widely chosen method to investigate quarkonium systems.…”