Abstract
Of the J/ψ mesons (inclusively) produced in pp collisions, a big fraction results from B decays, increasing with transverse momentum and exceeding 50% for pT > 20 GeV. These events must be subtracted in measurements of the polarization of prompt J/ψ mesons. While several studies have addressed the ψ(2S) and χc impact on the determination of the polarization of the directly-produced J/ψ mesons, the theoretical and experimental knowledge of the non-prompt polarization is very poor. Furthermore, non-prompt J/ψ polarization measurements can provide interesting information on quarkonium hadroproduction, complementing the studies of prompt production. We review the method of measuring the polarization of non-prompt J/ψ mesons (produced in decays of unreconstructed B mesons and detected in the dilepton channel), in conditions typical of LHC experiments studying J/ψ production. Realistic model-independent scenarios are validated with data from experiments studying e+e− → Υ(4S) interactions, converted to the high-momentum regime using B differential cross sections measured at the LHC. The non-prompt J/ψ polarization measurements are seen to remain dependent on the event selection criteria, even after correcting for the dilepton acceptance and efficiencies. This implies that reproducible definitions of all relevant analysis choices must be reported with the polarization result, for rigorous comparisons with other measurements and/or theoretical calculations. We also discuss how the non-prompt J/ψ polarization significantly depends on the relative importance of two complementary B → J/ψ decay topologies, two-body (reasonably dominated by singlet production) and multi-body (including octet contributions), providing, hence, valuable information for studies of the charmonium formation mechanisms.
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References
N. Brambilla et al., Heavy Quarkonium: Progress, Puzzles, and Opportunities, Eur. Phys. J. C 71 (2011) 1534 [arXiv:1010.5827] [INSPIRE].
R. Baier and R. Rückl, Hadronic Collisions: A Quarkonium Factory, Z. Phys. C 19 (1983) 251 [INSPIRE].
CDF collaboration, J/ψ and ψ(2S) production in \( p\overline{p} \) collisions at \( \sqrt{s} \) = 1.8 TeV, Phys. Rev. Lett. 79 (1997) 572 [INSPIRE].
CDF collaboration, Polarization of J/ψ and ψ(2S) Mesons Produced in \( p\overline{p} \) Collisions at \( \sqrt{s} \) = 1.96 TeV, Phys. Rev. Lett. 99 (2007) 132001 [arXiv:0704.0638] [INSPIRE].
CDF collaboration, Measurements of Angular Distributions of Muons From Υ Meson Decays in \( p\overline{p} \) Collisions at \( \sqrt{s} \) = 1.96 TeV, Phys. Rev. Lett. 108 (2012) 151802 [arXiv:1112.1591] [INSPIRE].
D0 collaboration, Measurement of the polarization of the Υ(1S) and Υ(2S) states in \( p\overline{p} \) collisions at \( \sqrt{s} \) = 1.96 TeV, Phys. Rev. Lett. 101 (2008) 182004 [arXiv:0804.2799] [INSPIRE].
CMS collaboration, Measurement of J/ψ and ψ(2S) Prompt Double-Differential Cross Sections in pp Collisions at \( \sqrt{s} \) = 7 TeV, Phys. Rev. Lett. 114 (2015) 191802 [arXiv:1502.04155] [INSPIRE].
CMS collaboration, Measurements of the Υ(1S), Υ(2S), and Υ(3S) differential cross sections in pp collisions at \( \sqrt{s} \) = 7 TeV, Phys. Lett. B 749 (2015) 14 [arXiv:1501.07750] [INSPIRE].
ATLAS collaboration, Measurement of the production cross-section of ψ(2S) → J/ψ(→ μ+μ−)π+π− in pp collisions at \( \sqrt{s} \) = 7 TeV at ATLAS, JHEP 09 (2014) 079 [arXiv:1407.5532] [INSPIRE].
ATLAS collaboration, Measurement of Upsilon production in 7 TeV pp collisions at ATLAS, Phys. Rev. D 87 (2013) 052004 [arXiv:1211.7255] [INSPIRE].
CMS collaboration, Measurement of the Prompt J/ψ and ψ(2S) Polarizations in pp Collisions at \( \sqrt{s} \) = 7 TeV, Phys. Lett. B 727 (2013) 381 [arXiv:1307.6070] [INSPIRE].
CMS collaboration, Measurement of the Y(1S), Y(2S) and Y(3S) Polarizations in pp Collisions at \( \sqrt{s} \) = 7 TeV, Phys. Rev. Lett. 110 (2013) 081802 [arXiv:1209.2922] [INSPIRE].
G.T. Bodwin, E. Braaten and G.P. Lepage, Rigorous QCD analysis of inclusive annihilation and production of heavy quarkonium, Phys. Rev. D 51 (1995) 1125 [Erratum ibid. 55 (1997) 5853] [hep-ph/9407339] [INSPIRE].
P. Faccioli, V. Knünz, C. Lourenço, J. Seixas and H.K. Wöhri, Quarkonium production in the LHC era: a polarized perspective, Phys. Lett. B 736 (2014) 98 [arXiv:1403.3970] [INSPIRE].
P. Faccioli, C. Lourenço, M. Araújo, V. Knünz, I. Krätschmer and J. Seixas, Quarkonium production at the LHC: A data-driven analysis of remarkably simple experimental patterns, Phys. Lett. B 773 (2017) 476 [arXiv:1702.04208] [INSPIRE].
G.T. Bodwin, K.-T. Chao, H.S. Chung, U.-R. Kim, J. Lee and Y.-Q. Ma, Fragmentation contributions to hadroproduction of promptJ/ψ, χcJ, and ψ(2S) states, Phys. Rev. D 93 (2016) 034041 [arXiv:1509.07904] [INSPIRE].
P. Faccioli, C. Lourenço, M. Araújo, J. Seixas, I. Krätschmer and V. Knünz, From identical S- and P-wave pT spectra to maximally distinct polarizations: probing NRQCD with χ states, Eur. Phys. J. C 78 (2018) 268 [arXiv:1802.01106] [INSPIRE].
LHCb collaboration, Measurement of J/ψ polarization in pp collisions at \( \sqrt{s} \) = 7 TeV, Eur. Phys. J. C 73 (2013) 2631 [arXiv:1307.6379] [INSPIRE].
LHCb collaboration, Measurement of ψ(2S) polarisation in pp collisions at \( \sqrt{s} \) = 7 TeV, Eur. Phys. J. C 74 (2014) 2872 [arXiv:1403.1339] [INSPIRE].
LHCb collaboration, Measurement of the ηc(1S) production cross-section in proton-proton collisions via the decay ηc(1S) → \( p\overline{p} \), Eur. Phys. J. C 75 (2015) 311 [arXiv:1409.3612] [INSPIRE].
LHCb collaboration, Measurement of the ηc(1S) production cross-section in pp collisions at \( \sqrt{s} \) = 13 TeV, Eur. Phys. J. C 80 (2020) 191 [arXiv:1911.03326] [INSPIRE].
M. Butenshön, Z.-G. He and B.A. Kniehl, ηc production at the LHC challenges nonrelativistic-QCD factorization, Phys. Rev. Lett. 114 (2015) 092004 [arXiv:1411.5287] [INSPIRE].
ATLAS collaboration, Measurement of the production cross section of prompt J/ψ mesons in association with a W± boson in pp collisions at \( \sqrt{s} \) = 7 TeV with the ATLAS detector, JHEP 04 (2014) 172 [arXiv:1401.2831] [INSPIRE].
ATLAS collaboration, Observation and measurements of the production of prompt and non-prompt J/ψ mesons in association with a Z boson in pp collisions at \( \sqrt{s} \) = 8 TeV with the ATLAS detector, Eur. Phys. J. C 75 (2015) 229 [arXiv:1412.6428] [INSPIRE].
ATLAS collaboration, Measurement of J/ψ production in association with a W± boson with pp data at 8 TeV, JHEP 01 (2020) 095 [arXiv:1909.13626] [INSPIRE].
M. Butenshön and B.A. Kniehl, New constraints on NRQCD long-distance matrix elements from J/ψ plus W/Z production at the CERN LHC, arXiv:2207.09366 [INSPIRE].
ALICE collaboration, Prompt and non-prompt J/ψ production cross sections at midrapidity in proton-proton collisions at \( \sqrt{s} \) = 5.02 and 13 TeV, JHEP 03 (2022) 190 [arXiv:2108.02523] [INSPIRE].
CMS collaboration, J/ψ and ψ(2S) production in pp collisions at \( \sqrt{s} \) = 7 TeV, JHEP 02 (2012) 011 [arXiv:1111.1557] [INSPIRE].
ATLAS collaboration, Measurement of the differential cross-sections of prompt and non-prompt production of J/ψ and ψ(2S) in pp collisions at \( \sqrt{s} \) = 7 and 8 TeV with the ATLAS detector, Eur. Phys. J. C 76 (2016) 283 [arXiv:1512.03657] [INSPIRE].
ALICE collaboration, J/ψ polarization in pp collisions at \( \sqrt{s} \) = 7 TeV, Phys. Rev. Lett. 108 (2012) 082001 [arXiv:1111.1630] [INSPIRE].
ALICE collaboration, Measurement of the inclusive J/ψ polarization at forward rapidity in pp collisions at \( \sqrt{s} \) = 8 TeV, Eur. Phys. J. C 78 (2018) 562 [arXiv:1805.04374] [INSPIRE].
CDF collaboration, Measurement of J/ψ and ψ(2S) polarization in \( p\overline{p} \) collisions at \( \sqrt{s} \) = 1.8 TeV, Phys. Rev. Lett. 85 (2000) 2886 [hep-ex/0004027] [INSPIRE].
CLEO collaboration, Inclusive decays of B mesons to charmonium, Phys. Rev. D 52 (1995) 2661 [INSPIRE].
BaBar collaboration, Study of inclusive production of charmonium mesons in B decay, Phys. Rev. D 67 (2003) 032002 [hep-ex/0207097] [INSPIRE].
CDF collaboration, Measurement of the B+ Total Cross Section and B+ Differential Cross Section dσ/dpT in \( p\overline{p} \) Collisions at \( \sqrt{s} \) = 1.8 TeV, Phys. Rev. D 65 (2002) 052005 [hep-ph/0111359] [INSPIRE].
ATLAS collaboration, Measurement of the differential cross-section of B+ meson production in pp collisions at \( \sqrt{s} \) = 7 TeV at ATLAS, JHEP 10 (2013) 042 [arXiv:1307.0126] [INSPIRE].
CMS collaboration, Measurement of the B+ Production Cross Section in pp Collisions at \( \sqrt{s} \) = 7 TeV, Phys. Rev. Lett. 106 (2011) 112001 [arXiv:1101.0131] [INSPIRE].
P. Faccioli, C. Lourenço, J. Seixas and H.K. Wöhri, Towards the experimental clarification of quarkonium polarization, Eur. Phys. J. C 69 (2010) 657 [arXiv:1006.2738] [INSPIRE].
P. Faccioli, C. Lourenço and J. Seixas, Rotation-invariant relations in vector meson decays into fermion pairs, Phys. Rev. Lett. 105 (2010) 061601 [arXiv:1005.2601] [INSPIRE].
P. Faccioli, C. Lourenço and J. Seixas, A New approach to quarkonium polarization studies, Phys. Rev. D 81 (2010) 111502 [arXiv:1005.2855] [INSPIRE].
M. Beneke, F. Maltoni and I.Z. Rothstein, QCD analysis of inclusive B decay into charmonium, Phys. Rev. D 59 (1999) 054003 [hep-ph/9808360] [INSPIRE].
M. Beneke, G.A. Schuler and S. Wolf, Quarkonium momentum distributions in photoproduction and B decay, Phys. Rev. D 62 (2000) 034004 [hep-ph/0001062] [INSPIRE].
S. Fleming, O.F. Hernandez, I. Maksymyk and H. Nadeau, NRQCD matrix elements in polarization of J/ψ produced from b decay, Phys. Rev. D 55 (1997) 4098 [hep-ph/9608413] [INSPIRE].
V. Krey and K.R.S. Balaji, Polarized J/ψ production from B mesons at the Tevatron, Phys. Rev. D 67 (2003) 054011 [hep-ph/0209135] [INSPIRE].
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Faccioli, P., Lourenço, C. On the polarization of the non-prompt contribution to inclusive J/ψ production in pp collisions. J. High Energ. Phys. 2022, 5 (2022). https://doi.org/10.1007/JHEP10(2022)010
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DOI: https://doi.org/10.1007/JHEP10(2022)010