Accessing the core of naturalness, nearly degenerate higgsinos, at the LHC

  • Chengcheng Han
  • Doyoun Kim
  • Shoaib Munir
  • Myeonghun Park
Open Access
Regular Article - Theoretical Physics


The presence of two light higgsinos nearly degenerate in mass is one of the important characteristics of supersymmetric models meeting the naturalness criteria. Probing such higgsinos at the LHC is very challenging, in particular when the mass-splitting between them is less than 5 GeV. In this study, we analyze such a degenerate higgsino scenario by exploiting the high collinearity between the two muons which originate from the decay of the heavier higgsino into the lighter one and which are accompanied by a high-p T QCD jet. Using our method, we can achieve a statistical significance ∼ 2.9 σ as well as S/B ∼ 17% with an integrated luminosity of 3000 fb−1 at the 14 TeV LHC, for the pair production of higgsinos with masses 124 GeV and 120 GeV. A good sensitivity can be achieved even for a smaller mass-splitting when the higgsinos are lighter.


Supersymmetry Phenomenology Jets 


Open Access

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  1. [1]
    ATLAS collaboration, Observation of a new particle in the search for the Standard Model Higgs boson with the ATLAS detector at the LHC, Phys. Lett. B 716 (2012) 1 [arXiv:1207.7214] [INSPIRE].ADSGoogle Scholar
  2. [2]
    CMS collaboration, Observation of a new boson at a mass of 125 GeV with the CMS experiment at the LHC, Phys. Lett. B 716 (2012) 30 [arXiv:1207.7235] [INSPIRE].ADSGoogle Scholar
  3. [3]
    M. Carena and H.E. Haber, Higgs boson theory and phenomenology, Prog. Part. Nucl. Phys. 50 (2003) 63 [hep-ph/0208209] [INSPIRE].ADSCrossRefGoogle Scholar
  4. [4]
    A. Arbey, M. Battaglia, A. Djouadi, F. Mahmoudi and J. Quevillon, Implications of a 125 GeV Higgs for supersymmetric models, Phys. Lett. B 708 (2012) 162 [arXiv:1112.3028] [INSPIRE].ADSCrossRefGoogle Scholar
  5. [5]
    M. Carena, S. Gori, N.R. Shah and C.E.M. Wagner, A 125 GeV SM-like Higgs in the MSSM and the γγ rate, JHEP 03 (2012) 014 [arXiv:1112.3336] [INSPIRE].ADSCrossRefGoogle Scholar
  6. [6]
    J. Cao, Z. Heng, D. Li and J.M. Yang, Current experimental constraints on the lightest Higgs boson mass in the constrained MSSM, Phys. Lett. B 710 (2012) 665 [arXiv:1112.4391] [INSPIRE].ADSCrossRefGoogle Scholar
  7. [7]
    J.-J. Cao, Z.-X. Heng, J.M. Yang, Y.-M. Zhang and J.-Y. Zhu, A SM-like Higgs near 125 GeV in low energy SUSY: a comparative study for MSSM and NMSSM, JHEP 03 (2012) 086 [arXiv:1202.5821] [INSPIRE].ADSCrossRefGoogle Scholar
  8. [8]
    J. Cao, Z. Heng, J.M. Yang and J. Zhu, Status of low energy SUSY models confronted with the LHC 125 GeV Higgs data, JHEP 10 (2012) 079 [arXiv:1207.3698] [INSPIRE].ADSCrossRefGoogle Scholar
  9. [9]
    CMS collaboration, Search for supersymmetry using razor variables in events with b-jets in pp collisions at 8 TeV, Phys. Rev. D 91 (2015) 052018 arXiv:1502.00300 [INSPIRE].ADSGoogle Scholar
  10. [10]
    CMS collaboration, Search for Supersymmetry in pp collisions at 8 TeV in events with a single lepton, multiple jets and b-tags, CMS-PAS-SUS-13-007.
  11. [11]
    ATLAS collaboration, Search for new phenomena using final states with large jet multiplicities and missing transverse momentum with ATLAS in 20 fb −1 of \( \sqrt{s}=8 \) TeV proton-proton collisions, ATLAS-CONF-2013-054, ATLAS-COM-CONF-2013-060.Google Scholar
  12. [12]
    ATLAS collaboration, Search for strong production of supersymmetric particles in final states with missing transverse momentum and at least three b-jets using 20.1 fb −1 of pp collisions at sqrt(s) = 8 TeV with the ATLAS Detector, JHEP 10 (2014) 024 [arXiv:1407.0600] [INSPIRE].ADSGoogle Scholar
  13. [13]
    D.M. Ghilencea, H.M. Lee and M. Park, Tuning supersymmetric models at the LHC: A comparative analysis at two-loop level, JHEP 07 (2012) 046 [arXiv:1203.0569] [INSPIRE].ADSCrossRefGoogle Scholar
  14. [14]
    R.L. Arnowitt and P. Nath, Loop corrections to radiative breaking of electroweak symmetry in supersymmetry, Phys. Rev. D 46 (1992) 3981 [INSPIRE].ADSGoogle Scholar
  15. [15]
    S.P. Martin, Non-universal gaugino masses from non-singlet F-terms in non-minimal unified models, Phys. Rev. D 79 (2009) 095019 [arXiv:0903.3568] [INSPIRE].ADSGoogle Scholar
  16. [16]
    J.E. Younkin and S.P. Martin, Non-universal gaugino masses, the supersymmetric little hierarchy problem and dark matter, Phys. Rev. D 85 (2012) 055028 [arXiv:1201.2989] [INSPIRE].ADSGoogle Scholar
  17. [17]
    S. Akula and P. Nath, Gluino-driven radiative breaking, Higgs boson mass, muon g-2 and the Higgs diphoton decay in supergravity unification, Phys. Rev. D 87 (2013) 115022 [arXiv:1304.5526] [INSPIRE].ADSGoogle Scholar
  18. [18]
    I. Gogoladze, F. Nasir and Q. Shafi, Non-Universal Gaugino Masses and Natural Supersymmetry, Int. J. Mod. Phys. A 28 (2013) 1350046 [arXiv:1212.2593] [INSPIRE].ADSCrossRefGoogle Scholar
  19. [19]
    C.H. Chen, M. Drees and J.F. Gunion, A Nonstandard string/SUSY scenario and its phenomenological implications, Phys. Rev. D 55 (1997) 330 [Erratum ibid. D 60 (1999) 039901] [hep-ph/9607421] [INSPIRE].
  20. [20]
    J.F. Gunion and S. Mrenna, A Study of SUSY signatures at the Tevatron in models with near mass degeneracy of the lightest chargino and neutralino, Phys. Rev. D 62 (2000) 015002 [hep-ph/9906270] [INSPIRE].ADSGoogle Scholar
  21. [21]
    C.H. Chen, M. Drees and J.F. Gunion, Searching for invisible and almost invisible particles at e + e colliders, Phys. Rev. Lett. 76 (1996) 2002 [hep-ph/9512230] [INSPIRE].ADSCrossRefGoogle Scholar
  22. [22]
    Q.-H. Cao, C.-R. Chen, C.S. Li and H. Zhang, Effective Dark Matter Model: Relic density, CDMS II, Fermi LAT and LHC, JHEP 08 (2011) 018 [arXiv:0912.4511] [INSPIRE].Google Scholar
  23. [23]
    M. Beltrán, D. Hooper, E.W. Kolb, Z.A.C. Krusberg and T.M.P. Tait, Maverick dark matter at colliders, JHEP 09 (2010) 037 [arXiv:1002.4137] [INSPIRE].ADSCrossRefGoogle Scholar
  24. [24]
    G.F. Giudice, T. Han, K. Wang and L.-T. Wang, Nearly Degenerate Gauginos and Dark Matter at the LHC, Phys. Rev. D 81 (2010) 115011 [arXiv:1004.4902] [INSPIRE].ADSGoogle Scholar
  25. [25]
    J. Goodman et al., Constraints on Dark Matter from Colliders, Phys. Rev. D 82 (2010) 116010 [arXiv:1008.1783] [INSPIRE].ADSGoogle Scholar
  26. [26]
    A. Rajaraman, W. Shepherd, T.M.P. Tait and A.M. Wijangco, LHC Bounds on Interactions of Dark Matter, Phys. Rev. D 84 (2011) 095013 [arXiv:1108.1196] [INSPIRE].ADSGoogle Scholar
  27. [27]
    P.J. Fox, R. Harnik, J. Kopp and Y. Tsai, Missing Energy Signatures of Dark Matter at the LHC, Phys. Rev. D 85 (2012) 056011 [arXiv:1109.4398] [INSPIRE].ADSGoogle Scholar
  28. [28]
    C. Han et al., Probing Light Higgsinos in Natural SUSY from Monojet Signals at the LHC, JHEP 02 (2014) 049 [arXiv:1310.4274] [INSPIRE].ADSCrossRefGoogle Scholar
  29. [29]
    P. Schwaller and J. Zurita, Compressed electroweakino spectra at the LHC, JHEP 03 (2014) 060 [arXiv:1312.7350] [INSPIRE].ADSCrossRefGoogle Scholar
  30. [30]
    ATLAS collaboration, Search for dark matter candidates and large extra dimensions in events with a jet and missing transverse momentum with the ATLAS detector, JHEP 04 (2013)075 [arXiv:1210.4491] [INSPIRE].ADSGoogle Scholar
  31. [31]
    CMS collaboration, Search for dark matter and large extra dimensions in monojet events in pp collisions at \( \sqrt{s}=7 \) TeV, JHEP 09 (2012) 094 [arXiv:1206.5663] [INSPIRE].ADSGoogle Scholar
  32. [32]
    CMS collaboration, Search for dark matter, extra dimensions and unparticles in monojet events in proton-proton collisions at \( \sqrt{s}=8 \) TeV, arXiv:1408.3583 [INSPIRE].
  33. [33]
    H. Baer, A. Mustafayev and X. Tata, Monojets and mono-photons from light higgsino pair production at LHC14, Phys. Rev. D 89 (2014) 055007 [arXiv:1401.1162] [INSPIRE].ADSGoogle Scholar
  34. [34]
    G. Brooijmans et al., Les Houches 2013: Physics at TeV Colliders: New Physics Working Group Report, arXiv:1405.1617 [INSPIRE].
  35. [35]
    A. Anandakrishnan, L.M. Carpenter and S. Raby, Degenerate gaugino mass region and mono-boson collider signatures, Phys. Rev. D 90 (2014) 055004 [arXiv:1407.1833] [INSPIRE].ADSGoogle Scholar
  36. [36]
    S. Gori, S. Jung, L.-T. Wang and J.D. Wells, Prospects for Electroweakino Discovery at a 100 TeV Hadron Collider, JHEP 12 (2014) 108 [arXiv:1410.6287] [INSPIRE].ADSCrossRefGoogle Scholar
  37. [37]
    K. Rolbiecki and K. Sakurai, Constraining compressed supersymmetry using leptonic signatures, JHEP 10 (2012) 071 [arXiv:1206.6767] [INSPIRE].ADSCrossRefGoogle Scholar
  38. [38]
    S. Gori, S. Jung and L.-T. Wang, Cornering electroweakinos at the LHC, JHEP 10 (2013) 191 [arXiv:1307.5952] [INSPIRE].ADSCrossRefGoogle Scholar
  39. [39]
    M. Berggren et al., Electroweakino Searches: A Comparative Study for LHC and ILC (A Snowmass White Paper), arXiv:1309.7342 [INSPIRE].
  40. [40]
    T. Han, S. Padhi and S. Su, Electroweakinos in the Light of the Higgs Boson, Phys. Rev. D 88 (2013) 115010 [arXiv:1309.5966] [INSPIRE].ADSGoogle Scholar
  41. [41]
    K.-i. Hikasa, T. Liu, L. Wang and J.M. Yang, Pseudo-goldstino and electroweak gauginos at the LHC, JHEP 07 (2014) 065 [arXiv:1403.5731] [INSPIRE].ADSCrossRefGoogle Scholar
  42. [42]
    T. Han, Z. Liu and S. Su, Light Neutralino Dark Matter: Direct/Indirect Detection and Collider Searches, JHEP 08 (2014) 093 [arXiv:1406.1181] [INSPIRE].ADSCrossRefGoogle Scholar
  43. [43]
    G. Barenboim, E.J. Chun, S. Jung and W.I. Park, Implications of an axino LSP for naturalness, Phys. Rev. D 90 (2014) 035020 [arXiv:1407.1218] [INSPIRE].ADSGoogle Scholar
  44. [44]
    J. Bramante, A. Delgado, F. Elahi, A. Martin and B. Ostdiek, Catching sparks from well-forged neutralinos, Phys. Rev. D 90 (2014) 095008 [arXiv:1408.6530] [INSPIRE].ADSGoogle Scholar
  45. [45]
    C. Han, L. Wu, J.M. Yang, M. Zhang and Y. Zhang, New approach for detecting a compressed bino/wino at the LHC, Phys. Rev. D 91 (2015) 055030 [arXiv:1409.4533] [INSPIRE].ADSGoogle Scholar
  46. [46]
    T.A.W. Martin and D. Morrissey, Electroweakino constraints from LHC data, JHEP 12 (2014) 168 [arXiv:1409.6322] [INSPIRE].ADSCrossRefGoogle Scholar
  47. [47]
    C. Han, Probing light bino and higgsinos at the LHC, arXiv:1409.7000 [INSPIRE].
  48. [48]
    T. Liu, L. Wang and J.M. Yang, Pseudo-goldstino and electroweakinos via VBF processes at LHC, JHEP 02 (2015) 177 [arXiv:1411.6105] [INSPIRE].ADSCrossRefGoogle Scholar
  49. [49]
    Z. Han and Y. Liu, MT2 to the Rescue - Searching for Sleptons in Compressed Spectra at the LHC, arXiv:1412.0618 [INSPIRE].
  50. [50]
    J. Bramante et al., Relic neutralino surface at a 100 TeV collider, Phys. Rev. D 91 (2015) 054015 [arXiv:1412.4789] [INSPIRE].ADSGoogle Scholar
  51. [51]
    A. Barr and J. Scoville, A boost for the EW SUSY hunt: monojet-like search for compressed sleptons at LHC14 with 100 fb −1, arXiv:1501.02511 [INSPIRE].
  52. [52]
    Z. Han, G.D. Kribs, A. Martin and A. Menon, Hunting quasidegenerate Higgsinos, Phys. Rev. D 89 (2014) 075007 [arXiv:1401.1235] [INSPIRE].ADSGoogle Scholar
  53. [53]
    H. Baer, A. Mustafayev and X. Tata, Monojet plus soft dilepton signal from light higgsino pair production at LHC14, Phys. Rev. D 90 (2014) 115007 [arXiv:1409.7058] [INSPIRE].ADSGoogle Scholar
  54. [54]
    C. Brust, A. Katz, S. Lawrence and R. Sundrum, SUSY, the Third Generation and the LHC, JHEP 03 (2012) 103 [arXiv:1110.6670] [INSPIRE].ADSCrossRefGoogle Scholar
  55. [55]
    M. Papucci, J.T. Ruderman and A. Weiler, Natural SUSY Endures, JHEP 09 (2012) 035 [arXiv:1110.6926] [INSPIRE].ADSCrossRefGoogle Scholar
  56. [56]
    L.J. Hall, D. Pinner and J.T. Ruderman, A Natural SUSY Higgs Near 126 GeV, JHEP 04 (2012) 131 [arXiv:1112.2703] [INSPIRE].ADSCrossRefGoogle Scholar
  57. [57]
    J.L. Feng and D. Sanford, A Natural 125 GeV Higgs Boson in the MSSM from Focus Point Supersymmetry with A-Terms, Phys. Rev. D 86 (2012) 055015 [arXiv:1205.2372] [INSPIRE].ADSGoogle Scholar
  58. [58]
    J. Cao, C. Han, L. Wu, J.M. Yang and Y. Zhang, Probing Natural SUSY from Stop Pair Production at the LHC, JHEP 11 (2012) 039 [arXiv:1206.3865] [INSPIRE].ADSCrossRefGoogle Scholar
  59. [59]
    H. Baer, V. Barger, P. Huang, A. Mustafayev and X. Tata, Radiative natural SUSY with a 125 GeV Higgs boson, Phys. Rev. Lett. 109 (2012) 161802 [arXiv:1207.3343] [INSPIRE].ADSCrossRefGoogle Scholar
  60. [60]
    C. Han, F. Wang and J.M. Yang, Natural SUSY from SU(5) Orbifold GUT, JHEP 11 (2013) 197 [arXiv:1304.5724] [INSPIRE].ADSCrossRefGoogle Scholar
  61. [61]
    C. Han, K.-i. Hikasa, L. Wu, J.M. Yang and Y. Zhang, Current experimental bounds on stop mass in natural SUSY, JHEP 10 (2013) 216 [arXiv:1308.5307] [INSPIRE].ADSCrossRefGoogle Scholar
  62. [62]
    K. Kowalska and E.M. Sessolo, Natural MSSM after the LHC 8 TeV run, Phys. Rev. D 88 (2013) 075001 [arXiv:1307.5790] [INSPIRE].ADSGoogle Scholar
  63. [63]
    A. Djouadi, M.M. Muhlleitner and M. Spira, Decays of supersymmetric particles: The Program SUSY-HIT (SUspect-SdecaY-HDECAY-InTerface), Acta Phys. Polon. B 38 (2007) 635 [hep-ph/0609292] [INSPIRE].ADSGoogle Scholar
  64. [64]
    XENON1T collaboration, E. Aprile, The XENON1T Dark Matter Search Experiment, Springer Proc. Phys. C12-02-22 (2013) 93 [arXiv:1206.6288] [INSPIRE].
  65. [65]
    CMS collaboration, Search for disappearing tracks in proton-proton collisions at \( \sqrt{s}=8 \) TeV, JHEP 01 (2015) 096 [arXiv:1411.6006] [INSPIRE].Google Scholar
  66. [66]
    N. Arkani-Hamed and N. Weiner, LHC Signals for a SuperUnified Theory of Dark Matter, JHEP 12 (2008) 104 [arXiv:0810.0714] [INSPIRE].ADSCrossRefGoogle Scholar
  67. [67]
    N. Arkani-Hamed, D.P. Finkbeiner, T.R. Slatyer and N. Weiner, A Theory of Dark Matter, Phys. Rev. D 79 (2009) 015014 [arXiv:0810.0713] [INSPIRE].ADSGoogle Scholar
  68. [68]
    M. Baumgart, C. Cheung, J.T. Ruderman, L.-T. Wang and I. Yavin, Non-Abelian Dark Sectors and Their Collider Signatures, JHEP 04 (2009) 014 [arXiv:0901.0283] [INSPIRE].ADSCrossRefGoogle Scholar
  69. [69]
    A. Katz and R. Sundrum, Breaking the Dark Force, JHEP 06 (2009) 003 [arXiv:0902.3271] [INSPIRE].ADSCrossRefGoogle Scholar
  70. [70]
    C. Cheung, J.T. Ruderman, L.-T. Wang and I. Yavin, Lepton Jets in (Supersymmetric) Electroweak Processes, JHEP 04 (2010) 116 [arXiv:0909.0290] [INSPIRE].ADSCrossRefMATHGoogle Scholar
  71. [71]
    A. Falkowski, J.T. Ruderman, T. Volansky and J. Zupan, Hidden Higgs Decaying to Lepton Jets, JHEP 05 (2010) 077 [arXiv:1002.2952] [INSPIRE].ADSCrossRefGoogle Scholar
  72. [72]
    CMS collaboration, Search for a non-standard-model Higgs boson decaying to a pair of new light bosons in four-muon final states, Phys. Lett. B 726 (2013) 564 [arXiv:1210.7619] [INSPIRE].ADSGoogle Scholar
  73. [73]
    CMS collaboration, Search for Light Resonances Decaying into Pairs of Muons as a Signal of New Physics, JHEP 07 (2011) 098 [arXiv:1106.2375] [INSPIRE].ADSGoogle Scholar
  74. [74]
    J. Alwall et al., The automated computation of tree-level and next-to-leading order differential cross sections and their matching to parton shower simulations, JHEP 07 (2014) 079 [arXiv:1405.0301] [INSPIRE].ADSCrossRefGoogle Scholar
  75. [75]
    T. Sjöstrand, S. Mrenna and P.Z. Skands, PYTHIA 6.4 Physics and Manual, JHEP 05 (2006) 026 [hep-ph/0603175] [INSPIRE].ADSCrossRefMATHGoogle Scholar
  76. [76]
    DELPHES 3 collaboration, J. de Favereau et al., DELPHES 3, A modular framework for fast simulation of a generic collider experiment, JHEP 02 (2014) 057 [arXiv:1307.6346] [INSPIRE].ADSGoogle Scholar
  77. [77]
    M. Cacciari, G.P. Salam and G. Soyez, FastJet User Manual, Eur. Phys. J. C 72 (2012) 1896 [arXiv:1111.6097] [INSPIRE].ADSCrossRefGoogle Scholar
  78. [78]
    M. Cacciari, G.P. Salam and G. Soyez, The Anti-k(t) jet clustering algorithm, JHEP 04 (2008) 063 [arXiv:0802.1189] [INSPIRE].ADSCrossRefMATHGoogle Scholar
  79. [79]
    A. Denner, S. Dittmaier, T. Kasprzik and A. Mück, Electroweak corrections to monojet production at the LHC, Eur. Phys. J. C 73 (2013) 2297 [arXiv:1211.5078] [INSPIRE].ADSCrossRefGoogle Scholar
  80. [80]
    F. Caravaglios, M.L. Mangano, M. Moretti and R. Pittau, A New approach to multijet calculations in hadron collisions, Nucl. Phys. B 539 (1999) 215 [hep-ph/9807570] [INSPIRE].ADSCrossRefGoogle Scholar
  81. [81]
    ATLAS collaboration, Search for pair-produced third-generation squarks decaying via charm quarks or in compressed supersymmetric scenarios in pp collisions at \( \sqrt{s}=8 \) TeV with the ATLAS detector, Phys. Rev. D 90 (2014) 052008 [arXiv:1407.0608] [INSPIRE].ADSGoogle Scholar
  82. [82]
    G.F. Giudice, B. Gripaios and R. Mahbubani, Counting dark matter particles in LHC events, Phys. Rev. D 85 (2012) 075019 [arXiv:1108.1800] [INSPIRE].ADSGoogle Scholar
  83. [83]
    ATLAS collaboration, A search for prompt lepton-jets in pp collisions at \( \sqrt{s}=7 \) TeV with the ATLAS detector, Phys. Lett. B 719 (2013) 299 [arXiv:1212.5409] [INSPIRE].ADSGoogle Scholar

Copyright information

© The Author(s) 2015

Authors and Affiliations

  • Chengcheng Han
    • 1
  • Doyoun Kim
    • 1
  • Shoaib Munir
    • 1
  • Myeonghun Park
    • 1
    • 2
    • 3
  1. 1.Asia Pacific Center for Theoretical PhysicsPohangSouth Korea
  2. 2.Department of PhysicsPostechPohangSouth Korea
  3. 3.Kavli IPMU (WPI)The University of TokyoKashiwaJapan

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