English

$\Upsilon(nS)$ and $\chi_b(nP)$ production at hadron colliders in nonrelativistic QCD

High Energy Physics - Phenomenology 2016-07-29 v2

Abstract

Υ(nS)\Upsilon(nS) and χb(nP)\chi_b(nP) (n=1,2,3) production at the LHC is studied at next-to-leading order in αs\alpha_s in nonrelativistic QCD. Feeddown contributions from higher χb\chi_b and Υ\Upsilon states are all considered for lower Υ\Upsilon cross sections and polarizations. The long distance matrix elements (LDMEs) are extracted from the yield data, and then used to make predictions for the Υ(nS)\Upsilon(nS) polarizations, which are found to be consistent with the measured polarization data within errors. In particular, the Υ(3S)\Upsilon(3S) polarization puzzle can be understood by a large feeddown contribution from χb(3P)\chi_b(3P) states. Our results may provide a good description for both cross sections and polarizations of prompt Υ(nS)\Upsilon(nS) and χb(nP)\chi_b(nP) production at the LHC.

Keywords

Cite

@article{arxiv.1410.8537,
  title  = {$\Upsilon(nS)$ and $\chi_b(nP)$ production at hadron colliders in nonrelativistic QCD},
  author = {H. Han and Y. Q. Ma and C. Meng and H. S. Shao and Y. J. Zhang and K. T. Chao},
  journal= {arXiv preprint arXiv:1410.8537},
  year   = {2016}
}

Comments

The text and abstract are substantially changed due to the change in the fitting procedure: we now extract LDMEs of $\Upsilon(nS)$ and $\chi_b{nP}$ by fitting the yield data of the LHC (including cross sections measured by ATLAS, CMS, and LHCb), and then make predictions for the polarizations of $\Upsilon(nS)$