• Media type: E-Article
  • Title: Central exclusive production of J/ψ and ψ(2S) mesons in pp collisions at $$ \sqrt{s}=13 $$ TeV
  • Contributor: Aaij, R.; Adeva, B.; Adinolfi, M.; Aidala, C. A.; Ajaltouni, Z.; Akar, S.; Albicocco, P.; Albrecht, J.; Alessio, F.; Alexander, M.; Alfonso Albero, A.; Ali, S.; Alkhazov, G.; Alvarez Cartelle, P.; Alves, A. A.; Amato, S.; Amerio, S.; Amhis, Y.; An, L.; Anderlini, L.; Andreassi, G.; Andreotti, M.; Andrews, J. E.; Appleby, R. B.; [...]
  • Published: Springer Science and Business Media LLC, 2018
  • Published in: Journal of High Energy Physics, 2018 (2018) 10
  • Language: English
  • DOI: 10.1007/jhep10(2018)167
  • ISSN: 1029-8479
  • Origination:
  • Footnote:
  • Description: <jats:title>A<jats:sc>bstract</jats:sc> </jats:title> <jats:p>Measurements are reported of the central exclusive production of <jats:italic>J/ψ</jats:italic> and <jats:italic>ψ</jats:italic>(2<jats:italic>S</jats:italic>) mesons in <jats:italic>pp</jats:italic> collisions at a centre-of-mass energy of 13 TeV. Backgrounds are significantly reduced compared to previous measurements made at lower energies through the use of new forward shower counters. The products of the cross-sections and the branching fractions for the decays to dimuons, where both muons are within the pseudorapidity range 2<jats:italic>.</jats:italic>0 <jats:italic>&lt; η &lt;</jats:italic> 4<jats:italic>.</jats:italic>5, are measured to be</jats:p> <jats:p> <jats:disp-formula> <jats:alternatives> <jats:tex-math>$$ \begin{array}{c}\hfill {\sigma}_{J/\psi \to {\mu}^{+}{\mu}^{-}} = 435 \pm 18 \pm 11 \pm 17\ \mathrm{p}\mathrm{b}\hfill \\ {}\hfill {\sigma}_{\psi (2S)\to {\mu}^{+}{\mu}^{-}} = 11.1 \pm 1.1 \pm 0.3 \pm 0.4\ \mathrm{p}\mathrm{b}.\hfill \end{array} $$</jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mtable> <mml:mtr> <mml:mtd> <mml:msub> <mml:mi>σ</mml:mi> <mml:mrow> <mml:mi>J</mml:mi> <mml:mo>/</mml:mo> <mml:mi>ψ</mml:mi> <mml:mo>→</mml:mo> <mml:msup> <mml:mi>μ</mml:mi> <mml:mo>+</mml:mo> </mml:msup> <mml:msup> <mml:mi>μ</mml:mi> <mml:mo>−</mml:mo> </mml:msup> </mml:mrow> </mml:msub> <mml:mo>=</mml:mo> <mml:mspace /> <mml:mn>435</mml:mn> <mml:mspace /> <mml:mo>±</mml:mo> <mml:mspace /> <mml:mn>18</mml:mn> <mml:mspace /> <mml:mo>±</mml:mo> <mml:mspace /> <mml:mn>11</mml:mn> <mml:mspace /> <mml:mo>±</mml:mo> <mml:mspace /> <mml:mn>17</mml:mn> <mml:mspace /> <mml:mi>p</mml:mi> <mml:mi>b</mml:mi> </mml:mtd> </mml:mtr> <mml:mtr> <mml:mtd> <mml:msub> <mml:mi>σ</mml:mi> <mml:mrow> <mml:mi>ψ</mml:mi> <mml:mfenced> <mml:mrow> <mml:mn>2</mml:mn> <mml:mi>S</mml:mi> </mml:mrow> </mml:mfenced> <mml:mo>→</mml:mo> <mml:msup> <mml:mi>μ</mml:mi> <mml:mo>+</mml:mo> </mml:msup> <mml:msup> <mml:mi>μ</mml:mi> <mml:mo>−</mml:mo> </mml:msup> </mml:mrow> </mml:msub> <mml:mo>=</mml:mo> <mml:mspace /> <mml:mn>11.1</mml:mn> <mml:mspace /> <mml:mo>±</mml:mo> <mml:mspace /> <mml:mn>1.1</mml:mn> <mml:mspace /> <mml:mo>±</mml:mo> <mml:mspace /> <mml:mn>0.3</mml:mn> <mml:mspace /> <mml:mo>±</mml:mo> <mml:mspace /> <mml:mn>0.4</mml:mn> <mml:mspace /> <mml:mi>p</mml:mi> <mml:mi>b</mml:mi> <mml:mtext>.</mml:mtext> </mml:mtd> </mml:mtr> </mml:mtable> </mml:math> </jats:alternatives> </jats:disp-formula> </jats:p> <jats:p>The first uncertainties are statistical, the second are systematic, and the third are due to the luminosity determination. The cross-sections are also measured differentially for meson rapidities between 2.0 and 4.5. Good agreement is observed with theoretical predictions. Photoproduction cross-sections are derived and compared to previous experiments, and a deviation from a pure power-law extrapolation of lower energy data is observed. </jats:p>
  • Access State: Open Access