Abstract
The polarization of the Y(1S), Y(2S) and Y(3S) mesons, produced in pp collisions at centre-of-mass energies \( \sqrt{s}=7 \) and 8 TeV, is measured using data samples collected by the LHCb experiment, corresponding to integrated luminosities of 1 and 2 fb−1, respectively. The measurements are performed in three polarization frames, using Y → μμ decays in the kinematic region of the transverse momentum p ΥT < 30 GeV/c and rapidity 2.2 < yY < 4.5. No large polarization is observed.
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E. Braaten and J. Russ, J/ψ and Y polarization in hadronic production processes, Ann. Rev. Nucl. Part. Sci. 64 (2014) 221 [arXiv:1401.7352] [INSPIRE].
P. Faccioli, V. Knünz, C. Lourenco, 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].
W.E. Caswell and G.P. Lepage, Effective Lagrangians for bound state problems in QED, QCD and other field theories, Phys. Lett. B 167 (1986) 437 [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. D 55 (1997) 5853] [hep-ph/9407339] [INSPIRE].
E. Braaten and S. Fleming, Color octet fragmentation and the ψ′ surplus at the Tevatron, Phys. Rev. Lett. 74 (1995) 3327 [hep-ph/9411365] [INSPIRE].
V.G. Kartvelishvili, A.K. Likhoded and S.R. Slabospitsky, D meson and ψ meson production in hadronic interactions, Sov. J. Nucl. Phys. 28 (1978) 678 [Yad. Fiz. 28 (1978) 1315] [INSPIRE].
R. Baier and R. Rückl, Hadronic production of J/ψ and Y: transverse momentum distributions, Phys. Lett. B 102 (1981) 364 [INSPIRE].
E.L. Berger and D.L. Jones, Inelastic photoproduction of J/ψ and Y by gluons, Phys. Rev. D 23 (1981) 1521 [INSPIRE].
J.M. Campbell, F. Maltoni and F. Tramontano, QCD corrections to J/ψ and Y production at hadron colliders, Phys. Rev. Lett. 98 (2007) 252002 [hep-ph/0703113] [INSPIRE].
B. Gong and J.-X. Wang, Next-to-leading-order QCD corrections to J/ψ polarization at Tevatron and Large-Hadron-Collider energies, Phys. Rev. Lett. 100 (2008) 232001 [arXiv:0802.3727] [INSPIRE].
P. Artoisenet, J.M. Campbell, J.P. Lansberg, F. Maltoni and F. Tramontano, Y production at Fermilab Tevatron and LHC energies, Phys. Rev. Lett. 101 (2008) 152001 [arXiv:0806.3282] [INSPIRE].
J.-P. Lansberg, On the mechanisms of heavy-quarkonium hadroproduction, Eur. Phys. J. C 61 (2009) 693 [arXiv:0811.4005] [INSPIRE].
H. Han, Y.-Q. Ma, C. Meng, H.-S. Shao, Y.-J. Zhang and K.-T. Chao, Y(nS) and χ b (nP ) production at hadron colliders in nonrelativistic QCD, Phys. Rev. D 94 (2016) 014028 [arXiv:1410.8537] [INSPIRE].
B. Gong, L.-P. Wan, J.-X. Wang and H.-F. Zhang, Complete next-to-leading-order study on the yield and polarization of Y(1S, 2S, 3S) at the Tevatron and LHC, Phys. Rev. Lett. 112 (2014) 032001 [arXiv:1305.0748] [INSPIRE].
N. Brambilla et al., Heavy quarkonium: progress, puzzles and opportunities, Eur. Phys. J. C 71 (2011) 1534 [arXiv:1010.5827] [INSPIRE].
CDF collaboration, D. Acosta et al., Y production and polarization in \( p\overline{p} \) collisions at \( \sqrt{s}=1.8 \) TeV, Phys. Rev. Lett. 88 (2002) 161802 [INSPIRE].
LHCb collaboration, Measurement of Y production in pp collisions at \( \sqrt{s}=7 \) TeV, Eur. Phys. J. C 72 (2012) 2025 [arXiv:1202.6579] [CERN-PH-EP-2012-051] [LHCb-PAPER-2011-036] [INSPIRE].
LHCb collaboration, Production of J/ψ and Y mesons in pp collisions at \( \sqrt{s}=8 \) TeV, JHEP 06 (2013) 064 [arXiv:1304.6977] [CERN-PH-EP-2013-071] [LHCb-PAPER-2013-016] [INSPIRE].
LHCb collaboration, Measurement of Y production in pp collisions at \( \sqrt{s}=2.76 \) TeV, Eur. Phys. J. C 74 (2014) 2835 [arXiv:1402.2539] [CERN-PH-EP-2014-016] [LHCb-PAPER-2013-066] [INSPIRE].
LHCb collaboration, Forward production of Y mesons in pp collisions at \( \sqrt{s}=7 \) and 8 TeV, JHEP 11 (2015) 103 [arXiv:1509.02372] [LHCb-PAPER-2015-045] [CERN-PH-EP-2015-232] [INSPIRE].
CMS collaboration, Y production cross-section in pp collisions at \( \sqrt{s}=7 \) TeV, Phys. Rev. D 83 (2011) 112004 [arXiv:1012.5545] [INSPIRE].
ATLAS collaboration, Measurement of Y production in 7 TeV pp collisions at ATLAS, Phys. Rev. D 87 (2013) 052004 [arXiv:1211.7255] [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] [LHCb-PAPER-2013-008] [CERN-PH-EP-2013-130] [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] [LHCb-PAPER-2013-067] [CERN-PH-EP-2014-029] [INSPIRE].
D0 collaboration, V.M. Abazov et al., Observation of a narrow mass state decaying into Y(1S) + γ in \( p\overline{p} \) collisions at \( \sqrt{s}=1.96 \) TeV, Phys. Rev. D 86 (2012) 031103 [arXiv:1203.6034] [INSPIRE].
ATLAS collaboration, Observation of a new χ b state in radiative transitions to Y(1S) and Y(2S) at ATLAS, Phys. Rev. Lett. 108 (2012) 152001 [arXiv:1112.5154] [INSPIRE].
LHCb collaboration, Measurement of the fraction of Y(1S) originating from χ b (1P ) decays in pp collisions at \( \sqrt{s}=7 \) TeV, JHEP 11 (2012) 031 [arXiv:1209.0282] [CERN-PH-EP-2012-237] [LHCb-PAPER-2012-015] [INSPIRE].
LHCb collaboration, Study of χ b meson production in pp collisions at \( \sqrt{s}=7 \) and 8 TeV and observation of the decay χ b (3P ) → Y(3S)γ, Eur. Phys. J. C 74 (2014) 3092 [arXiv:1407.7734] [CERN-PH-EP-2014-178] [LHCb-PAPER-2014-031] [INSPIRE].
LHCb collaboration, Measurement of the χ b (3P ) mass and of the relative rate of χ b1(1P ) and χb2(1P ) production, JHEP 10 (2014) 088 [arXiv:1409.1408] [CERN-PH-EP-2014-206] [LHCb-PAPER-2014-040] [INSPIRE].
Y. Feng, B. Gong, L.-P. Wan and J.-X. Wang, An updated study of Y production and polarization at the Tevatron and LHC, Chin. Phys. C 39 (2015) 123102 [arXiv:1503.08439] [INSPIRE].
CDF collaboration, T. Aaltonen et al., Measurements of angular distributions of muons from Y 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, V.M. Abazov et al., Measurement of the polarization of the Y(1S) and Y(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 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].
R.J. Oakes, Muon pair production in strong interactions, Nuovo Cim. A 44 (1966) 440.
C.S. Lam and W.-K. Tung, A systematic approach to inclusive lepton pair production in hadronic collisions, Phys. Rev. D 18 (1978) 2447 [INSPIRE].
P. Faccioli, C. Lourenco, J. Seixas and H.K. Wöhri, Towards the experimental clarification of quarkonium polarization, Eur. Phys. J. C 69 (2010) 657 [arXiv:1006.2738] [INSPIRE].
M. Beneke, M. Krämer and M. Vänttinen, Inelastic photoproduction of polarized J/ψ, Phys. Rev. D 57 (1998) 4258 [hep-ph/9709376] [INSPIRE].
M. Jacob and G.C. Wick, On the general theory of collisions for particles with spin, Annals Phys. 7 (1959) 404 [Annals Phys. 281 (2000) 774] [INSPIRE].
LHCb collaboration, The LHCb detector at the LHC, 2008 JINST 3 S08005 [INSPIRE].
J.C. Collins and D.E. Soper, Angular distribution of dileptons in high-energy hadron collisions, Phys. Rev. D 16 (1977) 2219 [INSPIRE].
K. Gottfried and J.D. Jackson, On the connection between production mechanism and decay of resonances at high-energies, Nuovo Cim. 33 (1964) 309 [INSPIRE].
H.H. Barschall and W. Haeberli eds., Polarization phenomena in nuclear reactions: proceedings of 3rd international symposium on polarization phenomena in nuclear reactions, University of Wisconsin Press, Madison WI U.S.A., (1971).
NA10 collaboration, S. Falciano et al., Angular distributions of muon pairs produced by 194 GeV/c negative pions, Z. Phys. C 31 (1986) 513 [INSPIRE].
P. Faccioli, C. Lourenco 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. Lourenco and J. Seixas, A new approach to quarkonium polarization studies, Phys. Rev. D 81 (2010) 111502 [arXiv:1005.2855] [INSPIRE].
O.V. Teryaev, Kinematic azimuthal asymmetries and Lam-Tung relation, in Proceedings of XI Advanced Research Workshop on High Energy Spin Physics, DUBNA-SPIN-05, Dubna Russia, 27 September-1 October 2005, A.V. Efremov ed., Dubna Russia, (2006).
P. Faccioli, C. Lourenco, J. Seixas and H.K. Wöhri, Rotation-invariant observables in parity-violating decays of vector particles to fermion pairs, Phys. Rev. D 82 (2010) 096002 [arXiv:1010.1552] [INSPIRE].
P. Faccioli, C. Lourenco, J. Seixas and H.K. Wöhri, Model-independent constraints on the shape parameters of dilepton angular distributions, Phys. Rev. D 83 (2011) 056008 [arXiv:1102.3946] [INSPIRE].
LHCb collaboration, LHCb detector performance, Int. J. Mod. Phys. A 30 (2015) 1530022 [arXiv:1412.6352] [INSPIRE].
A.A. Alves Jr. et al., Performance of the LHCb muon system, 2013 JINST 8 P02022 [arXiv:1211.1346] [INSPIRE].
R. Aaij et al., The LHCb trigger and its performance in 2011, 2013 JINST 8 P04022 [arXiv:1211.3055] [INSPIRE].
T. Sjöstrand, S. Mrenna and P.Z. Skands, PYTHIA 6.4 physics and manual, JHEP 05 (2006) 026 [hep-ph/0603175] [INSPIRE].
LHCb collaboration, Handling of the generation of primary events in Gauss, the LHCb simulation framework, J. Phys. Conf. Ser. 331 (2011) 032047 [INSPIRE].
D.J. Lange, The EvtGen particle decay simulation package, Nucl. Instrum. Meth. A 462 (2001) 152 [INSPIRE].
P. Golonka and Z. Was, PHOTOS Monte Carlo: a precision tool for QED corrections in Z and W decays, Eur. Phys. J. C 45 (2006) 97 [hep-ph/0506026] [INSPIRE].
J. Allison et al., GEANT4 developments and applications, IEEE Trans. Nucl. Sci. 53 (2006) 270 [INSPIRE].
GEANT4 collaboration, S. Agostinelli et al., GEANT4: a simulation toolkit, Nucl. Instrum. Meth. A 506 (2003) 250 [INSPIRE].
LHCb collaboration, The LHCb simulation application, Gauss: design, evolution and experience, J. Phys. Conf. Ser. 331 (2011) 032023 [INSPIRE].
M. Bargiotti and V. Vagnoni, Heavy quarkonia sector in PYTHIA 6.324: tuning, validation and perspectives at LHC(b), CERN-LHCb-2007-042, CERN, Geneva Switzerland, June 2007.
LHCb collaboration, Measurement of the track reconstruction efficiency at LHCb, 2015 JINST 10 P02007 [arXiv:1408.1251] [INSPIRE].
F. Archilli et al., Performance of the muon identification at LHCb, 2013 JINST 8 P10020 [arXiv:1306.0249] [INSPIRE].
W.D. Hulsbergen, Decay chain fitting with a Kalman filter, Nucl. Instrum. Meth. A 552 (2005) 566 [physics/0503191] [INSPIRE].
T. Skwarnicki, A study of the radiative cascade transitions between the Upsilon-prime and Upsilon resonances, Ph.D. thesis, Institute of Nuclear Physics, Krakow Poland, (1986) [INSPIRE].
LHCb collaboration, Observation of J/ψ pair production in pp collisions at \( \sqrt{s}=7 \) TeV, Phys. Lett. B 707 (2012) 52 [arXiv:1109.0963] [LHCb-PAPER-2011-013] [CERN-PH-EP-2011-135] [INSPIRE].
Particle Data Group collaboration, C. Patrignani et al., Review of particle physics, Chin. Phys. C 40 (2016) 100001 [INSPIRE].
Y. Xie, sFit: a method for background subtraction in maximum likelihood fit, arXiv:0905.0724 [INSPIRE].
M. Pivk and F.R. Le Diberder, sPlot: a statistical tool to unfold data distributions, Nucl. Instrum. Meth. A 555 (2005) 356 [physics/0402083] [INSPIRE].
LHCb collaboration, Measurement of CP-violation and the B 0 s meson decay width difference with B 0 s → J/ψK + K − and B 0 s → J/ψπ + π − decays, Phys. Rev. D 87 (2013) 112010 [arXiv:1304.2600] [CERN-PH-EP-2013-055] [LHCb-PAPER-2013-002] [INSPIRE].
W.T. Eadie, D. Drijard, F.E. James, M. Roos and B. Sadoulet, Statistical methods in experimental physics, North Holland, Amsterdam The Netherlands, (1971).
O. Teryaev, Positivity constraints for quarkonia polarization, Nucl. Phys. Proc. Suppl. 214 (2011) 118 [INSPIRE].
O.V. Teryaev, Angular distributions of dileptons in hadronic and heavy ions collisions, in Proceedings of XIV Advanced research workshop on High Energy Spin Physics, DUBNA-SPIN-11, JINR, Dubna Russia, 20-24 September 2011, A.V. Efremov and S.V. Goloskokov eds., Dubna Russia, (2012).
C.S. Lam and W.-K. Tung, A parton model relation sans QCD modifications in lepton pair productions, Phys. Rev. D 21 (1980) 2712 [INSPIRE].
S. Palestini, Angular distribution and rotations of frame in vector meson decays into lepton pairs, Phys. Rev. D 83 (2011) 031503 [arXiv:1012.2485] [INSPIRE].
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ArXiv ePrint: 1709.01301
Deceased (J. Blouw, I. Raniuk, P. Rodriguez Perez).
C. Baesso, C. Göbel are associated to Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
N. Beliy, J. He, P.-R. Li, X. Lyu, M. Szymanski, D. Vieira, Y. Zheng are associated to Center for High Energy Physics, Tsinghua University, Beijing, China
H. Cai, L. Sun are associated to Center for High Energy Physics, Tsinghua University, Beijing, China
B. Dey, Y. Xie, H. Yin, J. Yu are associated to Center for High Energy Physics, Tsinghua University, Beijing, China
D.A. Milanes, I.A. Monroy, J.A. Rodriguez Lopez are associated to LPNHE, Université Pierre et Marie Curie, Université Paris Diderot, CNRS/IN2P3, Paris, France
O. Grünberg, M. Heß, N. Meinert, H. Viemann, R. Waldi are associated to Physikalisches Institut, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany
T. Likhomanenko, A. Malinin, O. Morgunova, A. Nogay, A. Petrov, V. Shevchenko are associated to Institute of Theoretical and Experimental Physics (ITEP), Moscow, Russia
A. Vagner is associated to Institute of Theoretical and Experimental Physics (ITEP), Moscow, Russia
L.M. Garcia Martin, L. Henry, F. Martinez Vidal, A. Oyanguren, C. Remon Alepuz, P. Ruiz Valls, J. Ruiz Vidal, C. Sanchez Mayordomo are associated to ICCUB, Universitat de Barcelona, Barcelona, Spain
C.J.G. Onderwater is associated to Nikhef National Institute for Subatomic Physics, Amsterdam, The Netherlands
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The LHCb collaboration., Aaij, R., Adeva, B. et al. Measurement of the Y(nS) polarizations in pp collisions at \( \sqrt{s}=7 \) and 8 TeV. J. High Energ. Phys. 2017, 110 (2017). https://doi.org/10.1007/JHEP12(2017)110
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DOI: https://doi.org/10.1007/JHEP12(2017)110