# Observation of $\Upsilon(\mathrm{1S})$ pair production in proton-proton collisions at $\sqrt{s}$ = 8 TeV

CMS Collaboration; Canelli, F; Caminada, L; Chiochia, V; Kilminster, B; Robmann, P; et al (2017). Observation of $\Upsilon(\mathrm{1S})$ pair production in proton-proton collisions at $\sqrt{s}$ = 8 TeV. Journal of High Energy Physics, 2017:13.

## Abstract

Pair production of $\Upsilon(\mathrm{1S})$ mesons is observed at the LHC in proton-proton collisions at $\sqrt{s} =$ 8 TeV by the CMS experiment in a data sample corresponding to an integrated luminosity of 20.7 fb$^{-1}$. Both $\Upsilon(\mathrm{1S})$ candidates are fully reconstructed via their decays to $\mu^{+}\mu^{- }$. The fiducial acceptance region is defined by an absolute $\Upsilon(\mathrm{1S})$ rapidity smaller than 2.0. The fiducial cross section for the production of $\Upsilon(\mathrm{1S})$ pairs, assuming that both mesons decay isotropically, is measured to be 68.8 $\pm$ 12.7 (stat) $\pm$ 7.4 (syst) $\pm$ 2.8 ($\mathcal{B}$) pb, where the third uncertainty comes from the uncertainty in the branching fraction of $\Upsilon(\mathrm{1S})$ decays to $\mu^{+}\mu^{-}$. Assuming instead that the $\Upsilon(\mathrm{1S})$ mesons are produced with different polarizations leads to variations in the measured cross section in the range from $-38\%$ to $+36\%$.

## Abstract

Pair production of $\Upsilon(\mathrm{1S})$ mesons is observed at the LHC in proton-proton collisions at $\sqrt{s} =$ 8 TeV by the CMS experiment in a data sample corresponding to an integrated luminosity of 20.7 fb$^{-1}$. Both $\Upsilon(\mathrm{1S})$ candidates are fully reconstructed via their decays to $\mu^{+}\mu^{- }$. The fiducial acceptance region is defined by an absolute $\Upsilon(\mathrm{1S})$ rapidity smaller than 2.0. The fiducial cross section for the production of $\Upsilon(\mathrm{1S})$ pairs, assuming that both mesons decay isotropically, is measured to be 68.8 $\pm$ 12.7 (stat) $\pm$ 7.4 (syst) $\pm$ 2.8 ($\mathcal{B}$) pb, where the third uncertainty comes from the uncertainty in the branching fraction of $\Upsilon(\mathrm{1S})$ decays to $\mu^{+}\mu^{-}$. Assuming instead that the $\Upsilon(\mathrm{1S})$ mesons are produced with different polarizations leads to variations in the measured cross section in the range from $-38\%$ to $+36\%$.

## Statistics

### Citations

Dimensions.ai Metrics
8 citations in Web of Science®
13 citations in Scopus®

### Altmetrics

Detailed statistics

Item Type: Journal Article, refereed, original work 07 Faculty of Science > Physics Institute 530 Physics English 2017 11 Jan 2017 17:24 17 Sep 2019 18:00 Springer 1029-8479 Gold Publisher DOI. An embargo period may apply. https://doi.org/10.1007/JHEP05(2017)013 arXiv:1610.07095