Dominant Spin-Flip Effects for the Hadronic Produced $J/\psi$ Polarization at TEVATRON

Abstract

Dominant spin-flip effects for the direct and prompt $J/\psi$ polarizations at TEVATRON run II with collision energy 1.96 TeV and rapidity cut $|y^{J/\psi }|<0.6$, have been systematically studied, especially, the spin-flip effect for the transition of $(c\bar{c}{)}_8{[}^3{S}_1]$ into $J/\psi$ has been carefully discussed. It is found that the spin-flip effect shall always dilute the $J/\psi$ polarization, and with a suitable choice of the parameters $a_{0,1}$ and $c_{0,1,2}$, the $J/\psi$ polarization puzzle can be solved to a certain degree. At large transverse momentum $p_t$, $\alpha$ for the prompt $J/\psi$ is reduced by $\sim 50$ for $f_0=v^2$ and by $\sim 80$ for $f_0=1$. We also study the indirect $J/\psi$ polarization from the $b$-decays, which however is slightly affected by the same spin-flip effect and then shall provide a better platform to determine the color-octet matrix elements.

19 pages, 5 figures. References added. Revised version to be published in Phys.Rev.D

References in corpus (4)

• Upsilon production at the Tevatron and the LHC
• QCD corrections to J/psi polarization of hadronproduction at Tevatron and LHC
• Hadroproduction of J/psi and Upsilon in association with a heavy-quark pair
• QCD corrections to polarization of J/ψand Υat Fermilab Tevatron and CERN LHC