Twist-3 Distribution Amplitudes of Scalar Mesons within the QCD Sum Rules and Its Application to the BSB \to S Transition Form Factors

Jan, 2013
14 pages
Published in:
  • Eur.Phys.J.A 49 (2013) 78
  • Published: 2013
e-Print:

Citations per year

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Abstract: (arXiv)
We investigate the twist-3 light-cone distribution amplitudes (LCDAs) of the scalar mesons a0a_0, K0K^{\ast}_0 and f0f_0 within the QCD sum rules. The QCD sum rules are improved by a consistent treatment of the sizable ss-quark mass effects within the framework of the background field approach. Adopting the valence quark component (qˉ1q2)(\bar{q}_1 q_2) as the dominant structure of the scalar mesons, our estimation for their masses are close to the measured a0(1450)a_0(1450), K0(1430)K^{\ast}_0(1430) and f0(1710)f_0(1710). From the sum rules, we obtain the first two non-zero moments of the twist-3 LCDAs ϕa0s,σ\phi^{s,\sigma}_{a_0}: ξs,a02(4)=0.369  (0.245)\langle \xi_{s,a_0}^{2(4)} \rangle=0.369 \;(0.245) and ξσ,a02(4)=0.203  (0.093)\langle \xi_{\sigma,a_0}^{2(4)} \rangle=0.203 \;(0.093); those of the twist-3 LCDAs ϕK0s,σ\phi_{K^*_0}^{s,\sigma}: ξs,K01(2)=0.004  (0.355)\langle \xi_{s,K^{\ast}_0}^{1(2)} \rangle =0.004\;(0.355) and ξσ,K01(2)=0.018  (0.207)\langle \xi_{\sigma,K^{\ast}_0}^{1(2)} \rangle =0.018\;(0.207); and those of the twist-3 LCDAs ϕf0s,σ\phi_{f_0}^{s,\sigma}: ξs,f02(4)=0.335  (0.212)\langle \xi_{s,f_0}^{2(4)} \rangle=0.335 \;(0.212) and ξσ,f02(4)=0.196  (0.088)\langle \xi_{\sigma,f_0}^{2(4)} \rangle=0.196 \; (0.088), respectively. As an application of those twist-3 LCDAs, we study the BSB \to S transition form factors by introducing proper chiral currents into the correlator, which is constructed such that the twist-3 LCDAs give dominant contribution and the twist-2 LCDAs make negligible contribution. Our results of the BSB \to S transition form factors at the large recoil region q20q^2 \simeq 0 are consistent with those obtained in the literature, which inversely shows the present twist-3 LCDAs are acceptable.
Note:
  • 14 pages, 12 figures, 7 tables
  • 11.55.Hx
  • 14.40.-n
  • 12.38.Aw
  • quantum chromodynamics: sum rule
  • form factor: transition
  • scalar meson: distribution amplitude
  • light cone
  • quark: valence
  • mass: effect
  • correlation function