Long-lived neutralino NLSPs



We investigate the collider signatures of heavy, long-lived, neutral particles that decay to charged particles plus missing energy. Specifically, we focus on the case of a neutralino NLSP decaying to Z and gravitino within the context of General Gauge Mediation. We show that a combination of searches using the inner detector and the muon spectrometer yields a wide range of potential early LHC discoveries for NLSP lifetimes () ranging from 10−1 − 105 mm. We further show that events from Z( + ) can be used for detailed kinematic reconstruction, leading to accurate determinations of the neutralino mass and lifetime. In particular, we examine the prospects for detailed event study at ATLAS using the ECAL (making use of its timing and pointing capabilities) together with the TRT, or using the muon spectrometer alone. Finally, we also demonstrate that there is a region in parameter space where the Tevatron could potentially discover new physics in the delayed Z( + ) + Open image in new window channel. While our discussion centers on gauge mediation, many of the results apply to any scenario with a long-lived neutral particle decaying to charged particles.


Supersymmetry Phenomenology 


  1. [1]
    M.J. Strassler and K.M. Zurek, Echoes of a hidden valley at hadron colliders, Phys. Lett. B 651 (2007) 374 [hep-ph/0604261] [SPIRES].ADSGoogle Scholar
  2. [2]
    M.J. Strassler and K.M. Zurek, Discovering the Higgs through highly-displaced vertices, Phys. Lett. B 661 (2008) 263 [hep-ph/0605193] [SPIRES].ADSGoogle Scholar
  3. [3]
    P. Meade, N. Seiberg and D. Shih, General Gauge Mediation, Prog. Theor. Phys. Suppl. 177 (2009) 143 [arXiv:0801.3278] [SPIRES].MATHCrossRefADSGoogle Scholar
  4. [4]
    M. Buican, P. Meade, N. Seiberg and D. Shih, Exploring General Gauge Mediation, JHEP 03 (2009) 016 [arXiv:0812.3668] [SPIRES].CrossRefMathSciNetADSGoogle Scholar
  5. [5]
    C. Cheung, A.L. Fitzpatrick and D. Shih, (Extra)Ordinary Gauge Mediation, JHEP 07 (2008) 054 [arXiv:0710.3585] [SPIRES].CrossRefMathSciNetADSGoogle Scholar
  6. [6]
    K. Agashe and M. Graesser, Improving the fine tuning in models of low energy gauge mediated supersymmetry breaking, Nucl. Phys. B 507 (1997) 3 [hep-ph/9704206] [SPIRES].CrossRefADSGoogle Scholar
  7. [7]
    G.F. Giudice and R. Rattazzi, Theories with gauge-mediated supersymmetry breaking, Phys. Rept. 322 (1999) 419 [hep-ph/9801271] [SPIRES].CrossRefADSGoogle Scholar
  8. [8]
    S. Ambrosanio, G.L. Kane, G.D. Kribs, S.P. Martin and S. Mrenna, Search for supersymmetry with a light gravitino at the Fermilab Tevatron and CERN LEP colliders, Phys. Rev. D 54 (1996) 5395 [hep-ph/9605398] [SPIRES].ADSGoogle Scholar
  9. [9]
    S. Dimopoulos, M. Dine, S. Raby and S.D. Thomas, Experimental Signatures of Low Energy Gauge Mediated Supersymmetry Breaking, Phys. Rev. Lett. 76 (1996) 3494 [hep-ph/9601367] [SPIRES].CrossRefADSGoogle Scholar
  10. [10]
    S. Dimopoulos, M. Dine, S. Raby, S.D. Thomas and J.D. Wells, Phenomenological implications of low energy supersymmetry breaking, Nucl. Phys. Proc. Suppl. 52A (1997) 38 [hep-ph/9607450] [SPIRES].CrossRefADSGoogle Scholar
  11. [11]
    S. Dimopoulos, S.D. Thomas and J.D. Wells, Sparticle spectroscopy and electroweak symmetry breaking with gauge-mediated supersymmetry breaking, Nucl. Phys. B 488 (1997) 39 [hep-ph/9609434] [SPIRES].CrossRefADSGoogle Scholar
  12. [12]
    J.A. Bagger, K.T. Matchev, D.M. Pierce and R.-j. Zhang, Weak-scale phenomenology in models with gauge-mediated supersymmetry breaking, Phys. Rev. D 55 (1997) 3188 [hep-ph/9609444] [SPIRES].ADSGoogle Scholar
  13. [13]
    K.T. Matchev and S.D. Thomas, Higgs and Z boson signatures of supersymmetry, Phys. Rev. D 62 (2000) 077702 [hep-ph/9908482] [SPIRES].ADSGoogle Scholar
  14. [14]
    H. Baer, P. G. Mercadante, X. Tata and Y. l. Wang, The Reach of Tevatron upgrades in gauge mediated supersymmetry breaking models, Phys. Rev. D 60 (1999) 055001 [hep-ph/9903333] [SPIRES].ADSGoogle Scholar
  15. [15]
    SUSY Working Group collaboration, R.L. Culbertson et al., Low scale and gauge mediated supersymmetry breaking at the Fermilab Tevatron Run II, hep-ph/0008070 [SPIRES].
  16. [16]
    H. Baer, P.G. Mercadante, X. Tata and Y.-l. Wang, The Reach of the CERN large hadron collider for gauge mediated supersymmetry breaking models, Phys. Rev. D 62 (2000) 095007 [hep-ph/0004001] [SPIRES].ADSGoogle Scholar
  17. [17]
    P. Meade, M. Reece and D. Shih, Prompt Decays of General Neutralino NLSPs at the Tevatron, JHEP 05 (2010) 105 [arXiv:0911.4130] [SPIRES].CrossRefADSGoogle Scholar
  18. [18]
    G.D. Kribs, A. Martin, T.S. Roy and M. Spannowsky, Discovering the Higgs Boson in New Physics Events using Jet Substructure, Phys. Rev. D 81 (2010) 111501 [arXiv:0912.4731] [SPIRES].ADSGoogle Scholar
  19. [19]
    S. Ambrosanio and G.A. Blair, Measuring gauge mediated supersymmetry breaking parameters at a 500 GeV e + e linear collider, Eur. Phys. J. C 12 (2000) 287 [hep-ph/9905403] [SPIRES].CrossRefADSGoogle Scholar
  20. [20]
    CDF collaboration, T. Aaltonen et al., Search for Heavy, Long-Lived Neutralinos that Decay to Photons at CDF II Using Photon Timing, Phys. Rev. D 78 (2008) 032015 [arXiv:0804.1043] [SPIRES].ADSGoogle Scholar
  21. [21]
    CDF collaboration, A. Abulencia et al., Search for heavy, long-lived particles that decay to photons at CDF II, Phys. Rev. Lett. 99 (2007) 121801 [arXiv:0704.0760] [SPIRES].CrossRefADSGoogle Scholar
  22. [22]
    M. Goncharov et al., The Timing system for the CDF electromagnetic calorimeters, Nucl. Instrum. Meth. A 565 (2006) 543 [physics/0512171] [SPIRES].ADSGoogle Scholar
  23. [23]
    D.A. Toback and P. Wagner, Prospects of searches for neutral, long-lived particles which decay to photons using timing at CDF, Phys. Rev. D 70 (2004) 114032 [hep-ph/0407022] [SPIRES].ADSGoogle Scholar
  24. [24]
    L. Goscilo, P. Traczyk, P. Zalewski and M. Kazana, Search for decaying in ight neutralino and long lived staus within Gauge Mediated Supersymmetry Breaking models, CMS-AN-2006-095.Google Scholar
  25. [25]
    P. Zalewski, Search for GMSB NLSPs at LHC, arXiv:0710.2647 [SPIRES].
  26. [26]
    K. Kawagoe, T. Kobayashi, M.M. Nojiri and A. Ochi, Study of the gauge mediation signal with non-pointing photons at the CERN LHC, Phys. Rev. D 69 (2004) 035003 [hep-ph/0309031] [SPIRES].ADSGoogle Scholar
  27. [27]
    D. Prieur, GMSB SUSY models with non pointing photons signatures in ATLAS at the LHC, hep-ph/0507083 [SPIRES].
  28. [28]
    D. Prieur, GMSB SUSY Models with Non Pointing Photons Signatures in ATLAS at the LHC, ATL-PHYS-PUB-2007-010, ATL-COM-PHYS-2007-013, March 2007.Google Scholar
  29. [29]
    S. Chang and M.A. Luty, Displaced Dark Matter at Colliders, arXiv:0906.5013 [SPIRES].
  30. [30]
    P. Meade, S. Nussinov, M. Papucci and T. Volansky, Searches for Long Lived Neutral Particles, JHEP 06 (2010) 029 [arXiv:0910.4160] [SPIRES].CrossRefADSGoogle Scholar
  31. [31]
    D. Ventura, Triggering on Long-Lived Neutral Particles at ATLAS, Talk at UW Seattle Join Theory/Experiment Long-Lived Particles Workshop, http://silicon.phys.washington.edu/LongLivedWorkshop/Talks.html.
  32. [32]
    D. Ventura, personal communication.Google Scholar
  33. [33]
    ATLAS collaboration, Triggering on Long-Lived Neutral Particles in the ATLAS Detector, ATLAS Note ATL-PHYS-PUB-2009-082.Google Scholar
  34. [34]
    M. Aharrouche et al., Time resolution of the ATLAS barrel liquid argon electromagnetic calorimeter, Nucl. Instrum. Meth. A 597 (2008) 178 [SPIRES].ADSGoogle Scholar
  35. [35]
    ATLAS Collaboration, Expected Performance of the ATLAS Experiment - Detector, Trigger and Physics, arXiv:0901.0512 [SPIRES].
  36. [36]
    R. Duda and P. Hart, Use of the Hough Transformation to Detect Lines and Curves in Pictures, Comm. ACM 15 (1972) 11.CrossRefGoogle Scholar
  37. [37]
    ATLAS collaboration, ATLAS muon spectrometer: Technical design report, http://atlas.web.cern.ch/Atlas/GROUPS/MUON/TDR/Web/TDR.html.
  38. [38]
    ATLAS collaboration, G. Aad et al., The ATLAS Experiment at the CERN Large Hadron Collider, 2008 JINST 3 S08003 [SPIRES].
  39. [39]
    J. Hobbs (ATLAS), personal communication.Google Scholar
  40. [40]
    ATLAS collaboration, ATLAS: Detector and physics performance technical design report. Volume 1, http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/TDR/TDR.html.
  41. [41]
    ATLAS collaboration, S. Giagu, Search for long-lived particles in ATLAS and CMS, arXiv:0810.1453 [SPIRES].
  42. [42]
    T. Sjöstrand, S. Mrenna and P.Z. Skands, PYTHIA 6.4 Physics and Manual, JHEP 05 (2006) 026 [hep-ph/0603175] [SPIRES].CrossRefADSGoogle Scholar
  43. [43]
    G. Corcella et al., HERWIG 6.5: an event generator for Hadron Emission Reactions With Interfering Gluons (including supersymmetric processes), JHEP 01 (2001) 010 [hep-ph/0011363] [SPIRES].CrossRefADSGoogle Scholar
  44. [44]
    P. Richardson, Spin correlations in Monte Carlo simulations, JHEP 11 (2001) 029 [hep-ph/0110108] [SPIRES].CrossRefADSGoogle Scholar
  45. [45]
    G. Corcella et al., HERWIG 6.5 release note, hep-ph/0210213 [SPIRES].
  46. [46]
    R. Leitner, P. Tas and V.V. Shmakova, Time resolution of the ATLAS Tile calorimeter and its performance for a measurement of heavy stable particles, ATL-TILECAL-PUB-2007-002 [SPIRES].
  47. [47]
    CMS collaboration, G.L. Bayatian et al., CMS physics: Technical design report, http://cmsdoc.cern.ch/cms/cpt/tdr/.
  48. [48]
    CMS collaboration, N. Darmenov et al., The CMS RPC system overview, AIP Conf. Proc. 1203 (2010) 43.CrossRefADSGoogle Scholar
  49. [49]
    CMS collaboration, S. Chatrchyan et al., Time Reconstruction and Performance of the CMS Electromagnetic Calorimeter, 2010 JINST 5 T03011 [arXiv:0911.4044] [SPIRES].ADSGoogle Scholar
  50. [50]
    J.-F. Genat, G. Varner, F. Tang and H.J. Frisch, Signal Processing for Pico-second Resolution Timing Measurements, Nucl. Instrum. Meth. A 607 (2009) 387 [arXiv:0810.5590] [SPIRES].ADSGoogle Scholar
  51. [51]
    The CDF collaboration, F. Abe et al., Search for long-lived parents of Z 0 bosons in \( p\bar{p} \) collisions at \( \sqrt {s} = 1.8\;TeV \), Phys. Rev. D 58 (1998) 051102 [hep-ex/9805017] [SPIRES].ADSGoogle Scholar
  52. [52]
    CDF collaboration, A.L. Scott, Search for long-lived parents of the Z 0 boson, Int. J. Mod. Phys. A 20 (2005) 3263 [hep-ex/0410019] [SPIRES].ADSGoogle Scholar
  53. [53]
    D0 collaboration, V.M. Abazov et al., Search for neutral, long-lived particles decaying into two muons in \( p\bar{p} \) collisions at \( \sqrt {s} = 1.96\;TeV \), Phys. Rev. Lett. 97 (2006) 161802 [hep-ex/0607028] [SPIRES].CrossRefADSGoogle Scholar
  54. [54]
    NuTeV collaboration, T. Adams et al., Observation of an anomalous number of dimuon events in a high energy neutrino beam, Phys. Rev. Lett. 87 (2001) 041801 [hep-ex/0104037] [SPIRES].CrossRefADSGoogle Scholar
  55. [55]
    D0 collaboration, V.M. Abazov et al., Search for long-lived particles decaying into electron or photon pairs with the D0 detector, Phys. Rev. Lett. 101 (2008) 111802 [arXiv:0806.2223] [SPIRES].CrossRefADSGoogle Scholar
  56. [56]
    D0 collaboration, V.M. Abazov et al., Search for Resonant Pair Production of long-lived particles decaying to \( b\bar{b} \) in \( p\bar{p} \) collisions at \( \sqrt {s} = 1.96\;TeV \), Phys. Rev. Lett. 103 (2009) 071801 [arXiv:0906.1787] [SPIRES].CrossRefADSGoogle Scholar

Copyright information

© SISSA, Trieste, Italy 2010

Authors and Affiliations

  1. 1.C.N. Yang Institute for Theoretical PhysicsStony Brook UniversityStony BrookU.S.A.
  2. 2.Princeton Center for Theoretical SciencePrinceton UniversityPrincetonU.S.A.
  3. 3.Institute for Advanced StudyPrincetonU.S.A.
  4. 4.Department of Physics and AstronomyRutgersPiscatawayU.S.A.

Personalised recommendations