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Non-exotic Z′ signals in + , \( b\overline{b} \) and \( t\overline{t} \) final states at the LHC

Abstract

In the attempt to fully profile a Z′ boson accessible at the Large Hadron Collider (LHC), we study the sensitivity of di-lepton (for the electron, muon and tauon cases) and di-quark (for the case of the heavy flavours, t and, possibly, b) samples to the nature of the new gauge state, for a one-dimensional class of non-exotic Z′ bosons. Assuming realistic final state reconstruction efficiencies and error estimates, we find that, depending on the CERN collider energy and luminosity, the best chances of extracting the Z′ quantum numbers occur when two or more of these channels are simultaneously explored, as none of them separately enables one to fully probe the parameter spaces of the aforementioned models. Effects of Standard Model (SM) background as well interferences between this and the various Z′ signals have been accounted for. A complete study of cross sections and asymmetries (both spatial and spin ones) makes clear the need for complementarity, especially for their disentanglement over the full parameter space.

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References

  1. [1]

    M. Schmaltz and D. Tucker-Smith, Little Higgs review, Ann. Rev. Nucl. Part. Sci. 55 (2005) 229 [hep-ph/0502182] [INSPIRE].

    ADS  Article  Google Scholar 

  2. [2]

    J.L. Hewett and M. Spiropulu, Particle physics probes of extra space-time dimensions, Ann. Rev. Nucl. Part. Sci. 52 (2002) 397 [hep-ph/0205106] [INSPIRE].

    ADS  Article  Google Scholar 

  3. [3]

    R.N. Mohapatra, Unification and Supersymmetry, Springer, New York, U.S.A. (1986).

    Google Scholar 

  4. [4]

    J.L. Hewett and T.G. Rizzo, Low-Energy Phenomenology of Superstring Inspired E 6 Models, Phys. Rept. 183 (1989) 193 [INSPIRE].

    ADS  Article  Google Scholar 

  5. [5]

    D. Chung, L. Everett, G. Kane, S. King, J.D. Lykken and L. T. Wang, The Soft supersymmetry breaking Lagrangian: Theory and applications, Phys. Rept. 407 (2005) 1 [hep-ph/0312378] [INSPIRE].

    ADS  Article  Google Scholar 

  6. [6]

    M.J. Strassler and K.M. Zurek, Echoes of a hidden valley at hadron colliders, Phys. Lett. B 651 (2007) 374 [hep-ph/0604261] [INSPIRE].

    ADS  Google Scholar 

  7. [7]

    CDF collaboration, T. Aaltonen et al., A Search for high-mass resonances decaying to dimuons at CDF, Phys. Rev. Lett. 102 (2009) 091805 [arXiv:0811.0053] [INSPIRE].

    ADS  Article  Google Scholar 

  8. [8]

    CDF collaboration, T. Aaltonen et al., Search for High-Mass e + e- Resonances in \( p\overline{p} \) Collisions at \( \sqrt{s}=1.96 \) -TeV, Phys. Rev. Lett. 102 (2009) 031801 [arXiv:0810.2059] [INSPIRE].

    ADS  Article  Google Scholar 

  9. [9]

    D0 Collaboration, D0 note 4375-CONF (2004).

  10. [10]

    D0 Collaboration, D0 note 4577-CONF (2004).

  11. [11]

    CMS collaboration, S. Chatrchyan et al., Search for narrow resonances in dilepton mass spectra in pp collisions at \( \sqrt{s}=7 \) TeV, Phys. Lett. B 714 (2012) 158 [arXiv:1206.1849] [INSPIRE].

    ADS  Google Scholar 

  12. [12]

    ATLAS collaboration, G. Aad et al., Search for high-mass resonances decaying to dilepton final states in pp collisions at a center-of-mass energy of 7 TeV with the ATLAS detector, arXiv:1209.2535 [INSPIRE].

  13. [13]

    A. Papaefstathiou and K. Sakurai, Determining the Helicity Structure of Third Generation Resonances, JHEP 06 (2012) 069 [arXiv:1112.3956] [INSPIRE].

    ADS  Article  Google Scholar 

  14. [14]

    L. Basso, K. Mimasu and S. Moretti, Zsignals in polarised top-antitop final states, JHEP 09 (2012) 024 [arXiv:1203.2542] [INSPIRE].

    ADS  Article  Google Scholar 

  15. [15]

    D. Choudhury, R.M. Godbole, S.D. Rindani and P. Saha, Top polarization, forward-backward asymmetry and new physics, Phys. Rev. D 84 (2011) 014023 [arXiv:1012.4750] [INSPIRE].

    ADS  Google Scholar 

  16. [16]

    R.M. Godbole, K. Rao, S.D. Rindani and R.K. Singh, On measurement of top polarization as a probe of \( t\overline{t} \) production mechanisms at the LHC, JHEP 11 (2010) 144 [arXiv:1010.1458] [INSPIRE].

    ADS  Article  Google Scholar 

  17. [17]

    B. Xiao, Y.-K. Wang, Z.-Q. Zhou and S.-h. Zhu, Edge Charge Asymmetry in Top Pair Production at the LHC, Phys. Rev. D 83 (2011) 057503 [arXiv:1101.2507] [INSPIRE].

    ADS  Google Scholar 

  18. [18]

    Z.-q. Zhou, B. Xiao, Y.-k. Wang and S.-h. Zhu, Discriminating Different Zs via Asymmetries at the LHC, Phys. Rev. D 83 (2011) 094022 [arXiv:1102.1044] [INSPIRE].

    ADS  Google Scholar 

  19. [19]

    E.L. Berger, Q.-H. Cao, C.-R. Chen and H. Zhang, Top Quark Polarization As A Probe of Models with Extra Gauge Bosons, Phys. Rev. D 83 (2011) 114026 [arXiv:1103.3274] [INSPIRE].

    ADS  Google Scholar 

  20. [20]

    R. Diener, S. Godfrey and T.A. Martin, Unravelling an Extra Neutral Gauge Boson at the LHC using Third Generation Fermions, Phys. Rev. D 83 (2011) 115008 [arXiv:1006.2845] [INSPIRE].

    ADS  Google Scholar 

  21. [21]

    T. Stelzer and S. Willenbrock, Spin correlation in top quark production at hadron colliders, Phys. Lett. B 374 (1996) 169 [hep-ph/9512292] [INSPIRE].

    ADS  Google Scholar 

  22. [22]

    G. Mahlon and S.J. Parke, Angular correlations in top quark pair production and decay at hadron colliders, Phys. Rev. D 53 (1996) 4886 [hep-ph/9512264] [INSPIRE].

    ADS  Google Scholar 

  23. [23]

    W. Bernreuther, A. Brandenburg, Z. Si and P. Uwer, Investigation of top quark spin correlations at hadron collider, hep-ph/0410197 [INSPIRE].

  24. [24]

    S. Jadach and Z. Was, in proceedings of Workshop on Z Physics at LEP1, G. Altarelli, R. Kleiss and C. Verzegnassi eds., preprint CERN 89-08 (1989).

  25. [25]

    J.D. Anderson, M.H. Austern and R.N. Cahn, Measurement of Z-prime couplings at future hadron colliders through decays to tau leptons, Phys. Rev. D 46 (1992) 290 [INSPIRE].

    ADS  Google Scholar 

  26. [26]

    ATLAS collaboration, G. Aad et al., Measurement of τ polarization in Wτν decays with the ATLAS detector in pp collisions at \( \sqrt{s}=7 \) TeV, Eur. Phys. J. C 72 (2012) 2062 [arXiv:1204.6720] [INSPIRE].

    ADS  Google Scholar 

  27. [27]

    ATLAS collaboration, Performance of the Reconstruction and Identification of Hadronic Tau Decays with ATLAS, ATLAS-CONF-2011-152 (2011).

  28. [28]

    F. Petriello and S. Quackenbush, Measuring Zcouplings at the CERN LHC, Phys. Rev. D 77 (2008) 115004 [arXiv:0801.4389] [INSPIRE].

    ADS  Google Scholar 

  29. [29]

    CMS collabotarion, Search for b-jet Resonances in pp Collisions at \( \sqrt{s}=7 \) TeV, PAS-EXO-11-008.

  30. [30]

    CMS collaboration, J. Olzem, Performance of the upgraded CMS pixel detector for the LHC phase 1, 2011 JINST 6 C12039 [INSPIRE].

  31. [31]

    B. Mele and G. Altarelli, Lepton spectra as a measure of b quark polarization at LEP, Phys. Lett. B 299 (1993) 345 [INSPIRE].

    ADS  Google Scholar 

  32. [32]

    G. Bonvicini and L. Randall, Optimized variables for the study of Λ b polarization, Phys. Rev. Lett. 73 (1994) 392 [hep-ph/9401299] [INSPIRE].

    ADS  Article  Google Scholar 

  33. [33]

    A.F. Falk and M.E. Peskin, Production, decay and polarization of excited heavy hadrons, Phys. Rev. D 49 (1994) 3320 [hep-ph/9308241] [INSPIRE].

    ADS  Google Scholar 

  34. [34]

    M. Tung, J. Bernabeu and J. Penarrocha, O(α s ) spin spin correlations for top and bottom quark production in e + e annihilation, Phys. Lett. B 418 (1998) 181 [hep-ph/9706444] [INSPIRE].

    ADS  Google Scholar 

  35. [35]

    ALEPH collaboration, D. Buskulic et al., Measurement of Λ b polarization in Z decays, Phys. Lett. B 365 (1996) 437 [INSPIRE].

    ADS  Google Scholar 

  36. [36]

    OPAL collaboration, G. Abbiendi et al., Measurement of the average polarization of b baryons in hadronic Z 0 decays, Phys. Lett. B 444 (1998) 539 [hep-ex/9808006] [INSPIRE].

    ADS  Google Scholar 

  37. [37]

    DELPHI collaboration, P. Abreu et al., Λ b polarization in Z 0 decays at LEP, Phys. Lett. B 474 (2000) 205 [INSPIRE].

    ADS  Google Scholar 

  38. [38]

    E. Accomando, A. Belyaev, L. Fedeli, S.F. King and C. Shepherd-Themistocleous, Zphysics with early LHC data, Phys. Rev. D 83 (2011) 075012 [arXiv:1010.6058] [INSPIRE].

    ADS  Google Scholar 

  39. [39]

    L. Basso, S. Moretti and G.M. Pruna, Theoretical constraints on the couplings of non-exotic minimal Zbosons, JHEP 08 (2011) 122 [arXiv:1106.4762] [INSPIRE].

    ADS  Article  Google Scholar 

  40. [40]

    F. del Aguila, M. Masip and M. Pérez-Victoria, Physical parameters and renormalization of U(1)a × U(1)b models, Nucl. Phys. B 456 (1995) 531 [hep-ph/9507455] [INSPIRE].

    ADS  Article  Google Scholar 

  41. [41]

    M.S. Carena, A. Daleo, B.A. Dobrescu and T.M. Tait, Zgauge bosons at the Tevatron, Phys. Rev. D 70 (2004) 093009 [hep-ph/0408098] [INSPIRE].

    ADS  Google Scholar 

  42. [42]

    P.H. Chankowski, S. Pokorski and J. Wagner, Z-prime and the Appelquist-Carrazzone decoupling, Eur. Phys. J. C 47 (2006) 187 [hep-ph/0601097] [INSPIRE].

    ADS  Article  Google Scholar 

  43. [43]

    A. Ferroglia, A. Lorca and J. J. van der Bij, The Zreconsidered, Annalen Phys. 16 (2007) 563 [hep-ph/0611174].

    ADS  MATH  Article  Google Scholar 

  44. [44]

    E. Salvioni, G. Villadoro and F. Zwirner, Minimal Z-prime models: Present bounds and early LHC reach, JHEP 11 (2009) 068 [arXiv:0909.1320] [INSPIRE].

    ADS  Article  Google Scholar 

  45. [45]

    F. del Aguila, G. Coughlan and M. Quirós, Gauge coupling renormalization with several U(1) factors, Nucl. Phys. B 307 (1988) 633 [Erratum ibid. B 312 (1989) 751] [INSPIRE].

  46. [46]

    T. Appelquist, B.A. Dobrescu and A.R. Hopper, Nonexotic neutral gauge bosons, Phys. Rev. D 68 (2003) 035012 [hep-ph/0212073] [INSPIRE].

    ADS  Google Scholar 

  47. [47]

    DELPHI collaboration, P. Abreu et al., A Study of radiative muon pair events at Z 0 energies and limits on an additional Zgauge boson, Z. Phys. C 65 (1995) 603 [INSPIRE].

    ADS  Google Scholar 

  48. [48]

    H. Murayama, I. Watanabe and K. Hagiwara, HELAS: HELicity amplitude subroutines for Feynman diagram evaluations, KEK Report 91-11 (1992) [INSPIRE].

  49. [49]

    T. Stelzer and W. Long, Automatic generation of tree level helicity amplitudes, Comput. Phys. Commun. 81 (1994) 357 [hep-ph/9401258] [INSPIRE].

    ADS  Article  Google Scholar 

  50. [50]

    J. Pumplin, D. Stump, J. Huston, H. Lai, P.M. Nadolsky and W. K. Tung, New generation of parton distributions with uncertainties from global QCD analysis, JHEP 07 (2002) 012 [hep-ph/0201195] [INSPIRE].

    ADS  Article  Google Scholar 

  51. [51]

    G.P. Lepage, A New Algorithm for Adaptive Multidimensional Integration, J. Comput. Phys. 27 (1978) 192 [Erratum preprint CLNS-80/447 (1980)] [INSPIRE].

  52. [52]

    A. Pukhov, CalcHEP 2.3: MSSM, structure functions, event generation, batchs and generation of matrix elements for other packages, hep-ph/0412191 [INSPIRE].

  53. [53]

    A. Semenov, LanHEP: A Package for automatic generation of Feynman rules in gauge models, hep-ph/9608488 [INSPIRE].

  54. [54]

    N.D. Christensen and C. Duhr, FeynRules - Feynman rules made easy, Comput. Phys. Commun. 180 (2009) 1614 [arXiv:0806.4194] [INSPIRE].

    ADS  Article  Google Scholar 

  55. [55]

    N.D. Christensen et al., A Comprehensive approach to new physics simulations, Eur. Phys. J. C 71 (2011) 1541 [arXiv:0906.2474] [INSPIRE].

    ADS  Google Scholar 

  56. [56]

    G. Brooijmanset al., Les Houches 2011: Physics at TeV Colliders New Physics Working Group Report, arXiv:1203.1488 [INSPIRE].

  57. [57]

    https://hepmdb.soton.ac.uk/.

  58. [58]

    https://feynrules.irmp.ucl.ac.be/wiki/B-L-SM.

  59. [59]

    R. Brown, D. Sahdev and K. Mikaelian, Probing higher order qcd: charge conjugation asymmetries from two gluon exchange, Phys. Rev. Lett. 43 (1979) 1069 [INSPIRE].

    ADS  Article  Google Scholar 

  60. [60]

    J.H. Kuhn and G. Rodrigo, Charge asymmetry of heavy quarks at hadron colliders, Phys. Rev. D 59 (1999) 054017 [hep-ph/9807420] [INSPIRE].

    ADS  Google Scholar 

  61. [61]

    M. Arai, N. Okada, K. Smolek and V. Simak, Influence of Zboson on top quark spin correlations at the LHC, Acta Phys. Polon. B 40 (2009) 93 [arXiv:0804.3740] [INSPIRE].

    ADS  Google Scholar 

  62. [62]

    K. Hagiwara and D. Zeppenfeld, Helicity Amplitudes for Heavy Lepton Production in e + e Annihilation, Nucl. Phys. B 274 (1986) 1 [INSPIRE].

    ADS  Article  Google Scholar 

  63. [63]

    J.L. Hewett, J. Shelton, M. Spannowsky, T.M. Tait and M. Takeuchi, \( A_{FB}^t \) Meets LHC, Phys. Rev. D 84 (2011) 054005 [arXiv:1103.4618] [INSPIRE].

    ADS  Google Scholar 

  64. [64]

    E. Alvarez, Improving top quark induced charge asymmetries at the LHC using \( t\overline{t} \) transverse momentum, Phys. Rev. D 85 (2012) 094026 [arXiv:1202.6622] [INSPIRE].

    ADS  Google Scholar 

  65. [65]

    CMS collaboration, CMS Physics Technical Design Report Volume I : Detector Performance and Software, CERN-LHCC-2006-001 (2006).

  66. [66]

    ATLAS collaboration, ATLAS detector and physics performance: Technical Design Report, 1, CERN-LHCC-99-014 (1999).

  67. [67]

    ATLAS collaboration, ATLAS detector and physics performance: Technical Design Report, 2, CERN-LHCC-99-015 (1999).

  68. [68]

    M. Frank, A. Hayreter and I. Turan, Top Quark Pair Production and Asymmetry at the Tevatron and LHC in Left-Right Models, Phys. Rev. D 84 (2011) 114007 [arXiv:1108.0998] [INSPIRE].

    ADS  Google Scholar 

  69. [69]

    CMS collaboration, b-Jet Identification in the CMS Experiment, CMS PAS BTV-11-004 (2012).

  70. [70]

    https://twiki.cern.ch/twiki/bin/view/CMSPublic/SWGuideCategoryBasedElectronID#Electron_Efficiency.

  71. [71]

    L. Basso, O. Fischer and J. van der Bij, A natural Zmodel with inverse seesaw and leptonic dark matter, arXiv:1207.3250 [INSPIRE].

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Correspondence to L. Basso.

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ArXiv ePrint: 1208.0019

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Basso, L., Mimasu, K. & Moretti, S. Non-exotic Z′ signals in + , \( b\overline{b} \) and \( t\overline{t} \) final states at the LHC. J. High Energ. Phys. 2012, 60 (2012). https://doi.org/10.1007/JHEP11(2012)060

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Keywords

  • Beyond Standard Model
  • Gauge Symmetry
  • Heavy Quark Physics