J/ψandψ(2S)Production in

F. Abe¹,

H. Akimoto²,

A. Akopian³

et al.

Abstract

We present a study of J/psi and psi(2S) production in p (p) over bar collisions, at root s = 1.8 TeV with the CDF detector at Fermilab. The J/psi and psi(2S) mesons are reconstructed using their mu(+)mu(-) decay modes. We have measured the inclusive production cross section for both mesons as a function of their transverse momentum in the central region, \eta\ < 0.6. We also measure the fraction of these events originating from b hadrons. We thus extract individual cross-sections for J/psi and psi(2S) mesons from b-quark decays and prompt production. We find a large excess (approximately a factor of 50) of direct psi(2S) production compared with predictions from the color singlet model

J/ψPolarization inppCollisions ats=7 TeVAbelev1, Quintana2, Adamová3 et al. 2012Phys. Rev. Lett.Self Cite1253530View full textAdd to dashboardCite

“…(2). The simulation includes, for the tracking chambers, a map of dead channels and the residual misalignment of the detection elements and, for the trigger chambers, an evaluation of their efficiency based on data.…”

“…Results obtained for charmonium production at the Tevatron collider in the 1990s [2] led theory to recognize the role of intermediate quark-antiquark color-octet states in the production process, in the framework of the nonrelativistic QCD model [3]. This approach brought the calculations of p t spectra to agree rather well with the data [4] (p t is the transverse momentum, i.e., the momentum component perpendicular to the colliding beam direction).…”

Measurement of the relative prompt production rate of χ c2 and χ c1 in pp collisions at $\sqrt{s} = 7\ \mathrm{TeV}$

“…The J/ ψ production cross section measurements at the Tevatron [1, 2] were found to disagree by about a factor of 50 with theoretical color-singlet calculations [3]. Soon after, the CDF experiment reported a χ c2 / χ c1 cross section ratio that extended up to p T (J/ ψ )≃10 GeV/ c , where p T is the transverse momentum, and favored χ c1 production over χ c2  [4].…”

χcJproduction associated with acc¯pair at hadron colliders

“…On the contrary, in collisions, the contribution of J=c associated production [8] was estimated to be several orders of magnitude smaller than the experimental data of J=c inclusive production [9]. In hadron collisions at the Tevatron, theoretical predictions [10,11] showed that the J=c þ c þ " c contribution was significant in the large p T region compared with the NLO result of non-c " c contributions, and the produced J=c is mainly unpolarized, which is analogous to the polarization of J=c in inclusive production [12,13]. The integrated cross section was also significant and showed a great measurable potential both at the Tevatron and Relativistic Heavy Ion Collider (RHIC).…”