The first observation of the concurrent production of two J/Psi mesons in proton-nucleus collisions is presented. The analysis is based on a proton-lead (pPb) data sample recorded at a nucleon-nucleon center-of-mass energy of 8.16 TeV by the CMS experiment at the CERN LHC and corresponding to an integrated luminosity of 174.6 nb ^(-1). The two J/Psi mesons are reconstructed in their mu+mu- decay channels with transverse momenta Pt > 6.5 GeV and rapidity |y| < 2.4. Events where one of theJ/Psi mesons is reconstructed in the dielectron channel are also considered in the search. The pPb -> J/Psi J/Psi + X process is observed with a significance of 5.3 standard deviations. The measured inclusive fiducial cross section, using the four-muon channel alone, is 22.0 +- 8.9 (stat. ) +- 1.5 (sys.) nb. A fit of the data to the expected rapidity separation for pairs of J/Psi mesons produced in single (SPS) and double (DPS) parton scatterings yields 16.5 +- 10.8 (stat. ) +- 0.1 (sys.) nb and 5.4 +- 6.2 (stat. ) +- 0.4 (sys.) nb, respectively. This latter result can be transformed into a lower bound on the effective DPS cross section, closely related to the squared average interparton transverse separation in the collision, of sigma_eff > 1 mb at 95% confidence level.

Observation of double J/Psi meson production in pPb collisions at sqrt(S_NN) = 8.16 TeV / Hayrapetyan, A., Tumasyan, A., Adam, W., Andrejkovic, J. W., Bergauer, T., Chatterjee, S., Damanakis, K., Dragicevic, M., Hussain, P. S., Jeitler, M., Krammer, N., Li, A., Liko, D., Mikulec, I., Schieck, J., Schöfbeck, R., Schwarz, D., Sonawane, M., Templ, S., Waltenberger, W., et al.. - In: PHYSICAL REVIEW D. - ISSN 2470-0010. - ELETTRONICO. - 110:(2024), pp. 092002.0-092002.0. [10.1103/physrevd.110.092002]

Observation of double J/Psi meson production in pPb collisions at sqrt(S_NN) = 8.16 TeV

Ciulli, V.;D'Alessandro, R.;Focardi, E.;Latino, G.;Lenzi, P.;Calandri, A.;
2024

Abstract

The first observation of the concurrent production of two J/Psi mesons in proton-nucleus collisions is presented. The analysis is based on a proton-lead (pPb) data sample recorded at a nucleon-nucleon center-of-mass energy of 8.16 TeV by the CMS experiment at the CERN LHC and corresponding to an integrated luminosity of 174.6 nb ^(-1). The two J/Psi mesons are reconstructed in their mu+mu- decay channels with transverse momenta Pt > 6.5 GeV and rapidity |y| < 2.4. Events where one of theJ/Psi mesons is reconstructed in the dielectron channel are also considered in the search. The pPb -> J/Psi J/Psi + X process is observed with a significance of 5.3 standard deviations. The measured inclusive fiducial cross section, using the four-muon channel alone, is 22.0 +- 8.9 (stat. ) +- 1.5 (sys.) nb. A fit of the data to the expected rapidity separation for pairs of J/Psi mesons produced in single (SPS) and double (DPS) parton scatterings yields 16.5 +- 10.8 (stat. ) +- 0.1 (sys.) nb and 5.4 +- 6.2 (stat. ) +- 0.4 (sys.) nb, respectively. This latter result can be transformed into a lower bound on the effective DPS cross section, closely related to the squared average interparton transverse separation in the collision, of sigma_eff > 1 mb at 95% confidence level.
2024
110
0
0
Hayrapetyan, A.; Tumasyan, A.; Adam, W.; Andrejkovic, J. W.; Bergauer, T.; Chatterjee, S.; Damanakis, K.; Dragicevic, M.; Hussain, P. S.; Jeitler, M.;...espandi
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Utilizza questo identificatore per citare o creare un link a questa risorsa: https://hdl.handle.net/2158/1439194
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