%0 Journal Article
%T Measurement of J/ψ-pair production in pp collisions at √s=13 TeV and study of gluon transverse-momentum dependent PDFs
%A LHCb Collaboration (Aaij, R. et al
%A Jaimes Elles, S. J.
%A Jashal, B. K.
%A Martinez-Vidal, F.
%A Oyanguren, A.
%A Rebollo De Miguel, M.
%A Sanderswood, I.
%A Zhuo, J.
%J Journal of High Energy Physics
%D 2024
%V 03
%N 3
%I Springer
%@ 1029-8479
%G English
%F LHCbCollaborationAaij_etal2024
%O WOS:001194594600001
%O exported from refbase (https://references.ific.uv.es/refbase/show.php?record=6050), last updated on Sun, 14 Apr 2024 09:40:51 +0000
%X The production cross-section of J/psi pairs in proton-proton collisions at a centre-of-mass energy of root s = 13TeV is measured using a data sample corresponding to an integrated luminosity of 4.2 fb(-1) collected by the LHCb experiment. The measurement is performed with both J/psi mesons in the transverse momentum range 0 < p(T) < 14 GeV/c and rapidity range 2.0 < y < 4.5. The cross-section of this process is measured to be 16.36 +/- 0.28 (stat) +/- 0.88 (syst) nb. The contributions from single-parton scattering and double-parton scattering are separated based on the dependence of the cross-section on the absolute rapidity difference Delta y between the two J/psi mesons. The effective cross-section of double-parton scattering is measured to be sigma(eff) = 13.1 +/- 1.8 (stat) +/- 2.3 (syst) mb. The distribution of the azimuthal angle phi(CS) of one of the J/psi mesons in the Collins-Soper frame and the p(T)-spectrum of the J/psi pairs are also measured for the study of the gluon transverse-momentum dependent distributions inside protons. The extracted values of < cos4 phi(CS)> and < cos2 phi(CS)> are consistent with zero, but the presence of azimuthal asymmetry at a few percent level is allowed.
%K Hadron-Hadron Scattering
%K Multi-Parton Interactions
%K QCD
%K Quarkonium
%R 10.1007/JHEP03(2024)088
%U https://arxiv.org/abs/2311.14085
%U https://doi.org/10.1007/JHEP03(2024)088
%P 088-40pp