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$$^{+141}_{-104}$$(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., et al. "Observation of triple J/ψ meson production in proton-proton collisions." Nature Physics, vol. 19, no. 3, Jan. 2023. https://doi.org/10.1038/s41567-022-01838-y
Tumasyan, A., Adam, W., Andrejkovic, J. W., Bergauer, T., Chatterjee, S., Damanakis, K., Dragicevic, M., Del Valle, A. Escalante, Frühwirth, R., Jeitler, M., Krammer, N., Lechner, L., Liko, D., Mikulec, I., Paulitsch, P., Pitters, F. M., Schieck, J., Schöfbeck, R., ... Vetens, W. (2023). Observation of triple J/ψ meson production in proton-proton collisions. Nature Physics, 19(3). https://doi.org/10.1038/s41567-022-01838-y
Tumasyan, A., Adam, W., Andrejkovic, J. W., et al., "Observation of triple J/ψ meson production in proton-proton collisions," Nature Physics 19, no. 3 (2023), https://doi.org/10.1038/s41567-022-01838-y
@article{osti_1831831,
author = {Tumasyan, A. and Adam, W. and Andrejkovic, J. W. and Bergauer, T. and Chatterjee, S. and Damanakis, K. and Dragicevic, M. and Del Valle, A. Escalante and Frühwirth, R. and Jeitler, M. and others},
title = {Observation of triple J/ψ meson production in proton-proton collisions},
annote = {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$^{+141}_{-104}$(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.},
doi = {10.1038/s41567-022-01838-y},
url = {https://www.osti.gov/biblio/1831831},
journal = {Nature Physics},
issn = {ISSN 1745-2473},
number = {3},
volume = {19},
place = {United States},
publisher = {Nature Publishing Group (NPG)},
year = {2023},
month = {01}}
Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States); Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
Sponsoring Organization:
USDOE Office of Science (SC), High Energy Physics (HEP)
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 262, Issue 2-3https://doi.org/10.1016/0168-9002(87)90887-4
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 506, Issue 3https://doi.org/10.1016/S0168-9002(03)01368-8
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 555, Issue 1-2https://doi.org/10.1016/j.nima.2005.08.106