Abstract
Current Large Hadron Collider (LHC) analyses are blind to compressed supersymmetry (SUSY) models with sleptons near the lightest super partner (LSP) in mass: \( {m}_{\tilde{l}}-{m}_{{\tilde{\chi}}_1^0} \) ≡ Δm ≲ 60 GeV. We present a search sensitive to the very compressed range 1 3 GeV < Δm < 24 GeV using the channel \( pp\to {\tilde{l}}^{+}{\tilde{l}}^{-} \) + jet → \( {l}^{+}{l}^{-}{\tilde{\chi}}_1^0{\tilde{\chi}}_1^0+ \) jet with soft same-flavor leptons and one hard jet from initial state radiation (p jT > 100 GeV). The sleptons recoil against the jet boosting them and their decay products, making the leptons detectable and providing substantial missing transverse momentum. We use the kinematic variable mT2 along with a different-flavor control region to reduce the large standard model backgrounds and control systematic uncertainty. We find the analysis should allow LHC14 with 100 fb−1 to search for degenerate left-handed selectrons and smuons in the compressed region up to \( {m}_{{\tilde{l}}_L} \) ≲ 150 GeV. In addition, it should be sensitive to \( {m}_{{\tilde{l}}_L} \) ≲ 110 GeV for the very challenging case of auto-concealed SUSY, in which left-handed sleptons decay to the Kaluza-Klein tower of a modulino LSP which lives in d = 6 extra dimensions. In both the compressed spectrum and auto-concealed SUSY scenarios this analysis will need more data to improve on LEP2 limits for right-handed sleptons due to their smaller cross sections.
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References
ATLAS and CMS collaborations, Supersymmetry searches at the LHC, arXiv:1211.3887 [INSPIRE].
ATLAS collaboration, Search for direct production of charginos, neutralinos and sleptons in final states with two leptons and missing transverse momentum in pp collisions at \( \sqrt{s} \) = 8 TeV with the ATLAS detector, JHEP 05 (2014) 071 [arXiv:1403.5294] [INSPIRE].
CMS collaboration, Searches for electroweak production of charginos, neutralinos and sleptons decaying to leptons and W, Z and Higgs bosons in pp collisions at 8 TeV, Eur. Phys. J. C 74 (2014) 3036 [arXiv:1405.7570] [INSPIRE].
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].
H.K. Dreiner, M. Krämer and J. Tattersall, How low can SUSY go? Matching, monojets and compressed spectra, Europhys. Lett. 99 (2012) 61001 [arXiv:1207.1613] [INSPIRE].
S. Mukhopadhyay, M.M. Nojiri and T.T. Yanagida, Compressed SUSY search at the 13 TeV LHC using kinematic correlations and structure of ISR jets, JHEP 10 (2014) 012 [arXiv:1403.6028] [INSPIRE].
C. Han, A. Kobakhidze, N. Liu, A. Saavedra, L. Wu and J.M. Yang, Probing Light Higgsinos in Natural SUSY from Monojet Signals at the LHC, JHEP 02 (2014) 049 [arXiv:1310.4274] [INSPIRE].
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].
CMS collaboration, Search for top squarks decaying to a charm quark and a neutralino in events with a jet and missing transverse momentum, CMS-PAS-SUS-13-009 (2014) [INSPIRE].
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].
Z. Han, G.D. Kribs, A. Martin and A. Menon, Hunting quasidegenerate Higgsinos, Phys. Rev. D 89 (2014) 075007 [arXiv:1401.1235] [INSPIRE].
P. Schwaller and J. Zurita, Compressed electroweakino spectra at the LHC, JHEP 03 (2014) 060 [arXiv:1312.7350] [INSPIRE].
C.G. Lester and D.J. Summers, Measuring masses of semi-invisibly decaying particles pair produced at hadron colliders, Phys. Lett. B 463 (1999) 99 [hep-ph/9906349] [INSPIRE].
A. Barr, C.G. Lester and P. Stephens, A variable for measuring masses at hadron colliders when missing energy is expected; m T2 : the truth behind the glamour , J. Phys. G 29 (2003) 2343 [hep-ph/0304226] [INSPIRE].
H.-C. Cheng and Z. Han, Minimal Kinematic Constraints and m T2, JHEP 12 (2008) 063 [arXiv:0810.5178] [INSPIRE].
CMS collaboration, Search for physics beyond the standard model in events with two opposite-sign same-flavor leptons, jets and missing transverse energy in pp collisions at \( \sqrt{s} \) = 8 TeV, CMS-PAS-SUS-12-019 (2014) [INSPIRE].
S. Dimopoulos, K. Howe, J. March-Russell and J. Scoville, Auto-Concealment of Supersymmetry in Extra Dimensions, arXiv:1412.0805 [INSPIRE].
B. Dutta et al., Probing Compressed Sleptons at the LHC using Vector Boson Fusion Processes, Phys. Rev. D 91 (2015) 055025 [arXiv:1411.6043] [INSPIRE].
Z. Han and Y. Liu, M T2 to the Rescue — Searching for Sleptons in Compressed Spectra at the LHC, arXiv:1412.0618 [INSPIRE].
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].
T. Sjöstrand, S. Mrenna and P.Z. Skands, PYTHIA 6.4 Physics and Manual, JHEP 05 (2006) 026 [hep-ph/0603175] [INSPIRE].
O. Shekhovtsova, I.M. Nugent, T. Przedzinski, P. Roig and Z. Was, MC generator TAUOLA: implementation of Resonance Chiral Theory for two and three meson modes. Comparison with experiment, AIP Conf. Proc. 1492 (2012) 62 [arXiv:1208.5420] [INSPIRE].
M. Drees, H.K. Dreiner, D. Schmeier, J. Tattersall and J.S. Kim, CheckMATE: Confronting your Favourite New Physics Model with LHC Data, Comput. Phys. Commun. 187 (2015) 227 [arXiv:1312.2591] [INSPIRE].
M. Cacciari and G.P. Salam, Dispelling the N 3 myth for the k t jet-finder, Phys. Lett. B 641 (2006) 57 [hep-ph/0512210] [INSPIRE].
A.L. Read, Presentation of search results: The CL s technique, J. Phys. G 28 (2002) 2693 [INSPIRE].
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].
M. Cacciari, G.P. Salam and G. Soyez, FastJet User Manual, Eur. Phys. J. C 72 (2012) 1896 [arXiv:1111.6097] [INSPIRE].
M. Cacciari, G.P. Salam and G. Soyez, The Anti-k t jet clustering algorithm, JHEP 04 (2008) 063 [arXiv:0802.1189] [INSPIRE].
ATLAS collaboration, Search for direct-slepton and direct-chargino production in final states with two opposite-sign leptons, missing transverse momentum and no jets in 20/fb of pp collisions at \( \sqrt{s} \) = 8 TeV with the ATLAS detector, ATLAS-CONF-2013-049 (2013) [INSPIRE].
G. Cullen, N. Greiner and G. Heinrich, Susy-QCD corrections to neutralino pair production in association with a jet, Eur. Phys. J. C 73 (2013) 2388 [arXiv:1212.5154] [INSPIRE].
LEP2 SUSY Working Group, Combined LEP Chargino Results, up to 208 GeV for large m0, LEPSUSYWG/01-03.1 (2004) and online at http://lepsusy.web.cern.ch/lepsusy/www/inos_moriond01/charginos_pub.html.
LEP2 SUSY Working Group, M. Berggren et al., Combined LEP Selectron/Smuon/Stau Results, 183-208 GeV, LEPSUSYWG/04-01.1 (2004) and online at http://lepsusy.web.cern.ch/lepsusy/www/sleptons_summer04/slep final.html.
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ArXiv ePrint: 1501.02511
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Barr, A., Scoville, J. A boost for the EW SUSY hunt: monojet-like search for compressed sleptons at LHC14 with 100 fb−1. J. High Energ. Phys. 2015, 147 (2015). https://doi.org/10.1007/JHEP04(2015)147
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DOI: https://doi.org/10.1007/JHEP04(2015)147