Protons consist of three valence quarks, two up-quarks and one down-quark, held together by gluons and a sea of quark-antiquark pairs. Collectively, quarks and gluons are referred to as partons. In a proton-proton collision, typically only one parton of each proton undergoes a hard scattering – referred to as single-parton scattering – leaving the remainder of each proton only slightly disturbed. Here, we report the study of double- and triple-parton scatterings through the simultaneous production of three J/ψ mesons, which consist of a charm quark-antiquark pair, in proton-proton collisions recorded with the CMS experiment at the Large Hadron Collider. We observed this process – reconstructed through the decays of J/ψ mesons into pairs of oppositely charged muons – with a statistical significance above five standard deviations. We measured the inclusive fiducial cross-section to be 272−104+141(stat)±17(syst)fb, and compared it to theoretical expectations for triple-J/ψ meson production in single-, double- and triple-parton scattering scenarios. Assuming factorization of multiple hard-scattering probabilities in terms of single-parton scattering cross-sections, double- and triple-parton scattering are the dominant contributions for the measured process.

Tumasyan, A., Adam, W., Andrejkovic, J., Bergauer, T., Chatterjee, S., Damanakis, K., et al. (2023). Observation of triple J/ψ meson production in proton-proton collisions. NATURE PHYSICS, 19(3), 338-350 [10.1038/s41567-022-01838-y].

Observation of triple J/ψ meson production in proton-proton collisions

Benaglia A.;Boldrini G.;Brivio F.;Cetorelli F.;De Guio F.;Dinardo M. E.;Ghezzi A.;Govoni P.;Guzzi L.;Lucchini M. T.;Malberti M.;Massironi A.;Moroni L.;Paganoni M.;Pinolini B. S.;Ragazzi S.;Valsecchi D.;Zuolo D.;Gerosa R.;
2023

Abstract

Protons consist of three valence quarks, two up-quarks and one down-quark, held together by gluons and a sea of quark-antiquark pairs. Collectively, quarks and gluons are referred to as partons. In a proton-proton collision, typically only one parton of each proton undergoes a hard scattering – referred to as single-parton scattering – leaving the remainder of each proton only slightly disturbed. Here, we report the study of double- and triple-parton scatterings through the simultaneous production of three J/ψ mesons, which consist of a charm quark-antiquark pair, in proton-proton collisions recorded with the CMS experiment at the Large Hadron Collider. We observed this process – reconstructed through the decays of J/ψ mesons into pairs of oppositely charged muons – with a statistical significance above five standard deviations. We measured the inclusive fiducial cross-section to be 272−104+141(stat)±17(syst)fb, and compared it to theoretical expectations for triple-J/ψ meson production in single-, double- and triple-parton scattering scenarios. Assuming factorization of multiple hard-scattering probabilities in terms of single-parton scattering cross-sections, double- and triple-parton scattering are the dominant contributions for the measured process.
Articolo in rivista - Articolo scientifico
LHC, CMS, J/Psi
English
2023
19
3
338
350
none
Tumasyan, A., Adam, W., Andrejkovic, J., Bergauer, T., Chatterjee, S., Damanakis, K., et al. (2023). Observation of triple J/ψ meson production in proton-proton collisions. NATURE PHYSICS, 19(3), 338-350 [10.1038/s41567-022-01838-y].
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/453737
Citazioni
  • Scopus 6
  • ???jsp.display-item.citation.isi??? 0
Social impact