Pion Decay Widths of D mesons

Abstract

The pionic decay rates of the excited $L=0,1$ $D$ mesons are calculated with a Hamiltonian model within the framework of the covariant Blankenbecler-Sugar {equation.} The interaction between the light quark and charm antiquark is described by a linear scalar confining and a screened one-gluon exchange interaction. The decay widths of the $D^{\ast }$ mesons obtain a contribution from the exchange current that is associated with the linear scalar confining interaction. If this contribution is taken into account along with the single quark approximation, the calculated decay rates of the charged $D^{\ast }$ mesons are readily below the current empirical upper limits if the axial coupling constant of the light constituent quarks is taken to be $g_A^q$ = 0.87, but reach the empirical upper limits if $g_A^q$ = 1. With the conventional values for $g_A^q$, the calculated widths of the $D_1$ and $D_2^{\ast }$ mesons fall somewhat below the experimental lower limits, leaving room for other decay modes as well, such as $\pi \pi$ decay. The unrealistically large contribution from the axial charge operator to the calculated pion decay width of the $D_1$ meson is suppressed by taking into account the exchange charge effects that are associated with the scalar linear confining and vector one-gluon exchange interactions. The predicted values for the pionic widths of the hitherto undiscovered L=1 $D_1^{\ast }$ and $D_0^{\ast }$ mesons are found to be smaller than previous estimates.

24 pages, 3 figures, uses feynmf typos corrected, to be published in Nuclear Physics A, accepted version

References in corpus (8)

• Mass spectrum of orbitally and radially excited heavy-light mesons in the relativistic quark model
• Heavy Mesons In A Relativistic Model
• Optimization of R(e+e-) and "Freezing" of the QCD Couplant at Low Energies
• Spectra and M1 Decay Widths of Heavy-Light Mesons
• A relativistic chiral quark model for pseudoscalar emission from heavy mesons
• The Confining Interaction and Radiative Decays of Heavy Quarkonia
• Baryon Magnetic Moments and Axial Coupling Constants with Relativistic and Exchange Current Effects
• Couplings of pions to higher positive parity heavy mesons

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• Strong decays of heavy-light mesons in a chiral quark model
• Exchange Current Operators and Electromagnetic Dipole Transitions in Heavy Quarkonia
• Five-quark components in $\Delta (1232)\to N\pi$ decay
• The role of five-quark components in gamma decay of the $\Delta (1232)$
• Structure and production mechanism of the enigmatic $X(3872)$ in high-energy hadronic reactions
• Pion Rescattering in Two-Pion Decay of Heavy Quarkonia
• The Coupling of eta Mesons to Quarks and Baryons from D_s^* -> D_s pi^0 Decay
• Two-Pion Decay Widths of Excited Charm Mesons
• Using pi_2(1670) -> b_1(1235) pi to Constrain Hadronic Models