Abstract
Searches at the Large Hadron Collider (LHC) for neutral, long-lived particles have historically relied on the detection of displaced particles produced by their decay within the detector volume. In this paper we study the potential of the complementary signature comprising of the missing transverse energy (E miss T ) signal, traditionally used to look for dark matter, e.g., the lightest supersymmetric particle (LSP), to extend the LHC coverage to models with long-lived (LL) particles when they decay outside the detector. Using CMS and ATLAS analyses at the 8 TeV LHC, we set an upper limit at the 95% confidence level (CL) on the production cross sections for two specific scenarios: (i) a model with a heavy non-standard model Higgs boson decaying to a LL scalar and (ii) an R-parity violating (RPV) SUSY model with a LL neutralino. We show that this method can significantly extend the LHC sensitivity to neutral, LL particles with arbitrary large lifetimes and that the limits obtained from a E miss T signal are comparable to those from displaced particle searches for decay distances above a few meters. Results obtained in this study do not depend on the specific decay channel of the LL particle and therefore are model-independent in this sense. We provide limits for the whole two-dimensional plane in terms of the mass of the LL particle and the mass of the mediator up to masses of 2 TeV including particular benchmarks studied in the original experimental papers. We have made these limits available in the form of a grid which can be used for the interpretation of various other new physics models.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
R. Barbier et al., R-parity violating supersymmetry, Phys. Rept. 420 (2005) 1 [hep-ph/0406039] [INSPIRE].
J.L. Hewett, B. Lillie, M. Masip and T.G. Rizzo, Signatures of long-lived gluinos in split supersymmetry, JHEP 09 (2004) 070 [hep-ph/0408248] [INSPIRE].
T. Han, Z. Si, K.M. Zurek and M.J. Strassler, Phenomenology of hidden valleys at hadron colliders, JHEP 07 (2008) 008 [arXiv:0712.2041] [INSPIRE].
H.-C. Cheng and I. Low, Little hierarchy, little Higgses and a little symmetry, JHEP 08 (2004) 061 [hep-ph/0405243] [INSPIRE].
H.-C. Cheng and I. Low, TeV symmetry and the little hierarchy problem, JHEP 09 (2003) 051 [hep-ph/0308199] [INSPIRE].
C.T. Hill and R.J. Hill, T − parity violation by anomalies, Phys. Rev. D 76 (2007) 115014 [arXiv:0705.0697] [INSPIRE].
L. Basso, A. Belyaev, S. Moretti and C.H. Shepherd-Themistocleous, Phenomenology of the minimal B-L extension of the standard model: Z ′ and neutrinos, Phys. Rev. D 80 (2009) 055030 [arXiv:0812.4313] [INSPIRE].
CMS collaboration, Search for displaced supersymmetry in events with an electron and a muon with large impact parameters, Phys. Rev. Lett. 114 (2015) 061801 [arXiv:1409.4789] [INSPIRE].
CMS collaboration, Search for long-lived particles that decay into final states containing two electrons or two muons in proton-proton collisions at \( \sqrt{s}=8 \) TeV, Phys. Rev. D 91 (2015) 052012 [arXiv:1411.6977] [INSPIRE].
CMS collaboration, Search for long-lived neutral particles decaying to quark-antiquark pairs in proton-proton collisions at \( \sqrt{s}=8 \) TeV, Phys. Rev. D 91 (2015) 012007 [arXiv:1411.6530] [INSPIRE].
ATLAS collaboration, Search for massive, long-lived particles using multitrack displaced vertices or displaced lepton pairs in pp collisions at \( \sqrt{s}=8 \) TeV with the ATLAS detector, Phys. Rev. D 92 (2015) 072004 [arXiv:1504.05162] [INSPIRE].
ATLAS collaboration, Search for pair-produced long-lived neutral particles decaying in the ATLAS hadronic calorimeter in pp collisions at \( \sqrt{s}=8 \) TeV, Phys. Lett. B 743 (2015) 15 [arXiv:1501.04020] [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].
P. Torrielli and S. Frixione, Matching NLO QCD computations with PYTHIA using MC@NLO, JHEP 04 (2010) 110 [arXiv:1002.4293] [INSPIRE].
A.V. Semenov, LanHEP: a package for automatic generation of Feynman rules in gauge models, hep-ph/9608488 [INSPIRE].
A.V. Semenov, LanHEP: a package for automatic generation of Feynman rules in field theory. Version 2.0, hep-ph/0208011 [INSPIRE].
A. Semenov, LanHEP — a package for automatic generation of Feynman rules from the Lagrangian. Updated version 3.1, arXiv:1005.1909 [INSPIRE].
M. Drees, H. Dreiner, D. Schmeier, J. Tattersall and J.S. Kim, CheckMATE: confronting your favourite new physics model with LHC data, Comput. Phys. Commun. 187 (2014) 227 [arXiv:1312.2591] [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 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].
M. Cacciari, G.P. Salam and G. Soyez, The anti-k t jet clustering algorithm, JHEP 04 (2008) 063 [arXiv:0802.1189] [INSPIRE].
A.L. Read, Presentation of search results: the CL s technique, J. Phys. G 28 (2002) 2693 [INSPIRE].
C.G. Lester and D.J. Summers, Measuring masses of semiinvisibly decaying particles pair produced at hadron colliders, Phys. Lett. B 463 (1999) 99 [hep-ph/9906349] [INSPIRE].
A. Barr, C. Lester and P. Stephens, m T 2 : 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 T 2, JHEP 12 (2008) 063 [arXiv:0810.5178] [INSPIRE].
CMS collaboration, Search for dark matter, extra dimensions and unparticles in monojet events in proton-proton collisions at \( \sqrt{s}=8 \) TeV, Eur. Phys. J. C 75 (2015) 235 [arXiv:1408.3583] [INSPIRE].
ATLAS collaboration, Search for squarks and gluinos with the ATLAS detector in final states with jets and missing transverse momentum and 20.3 fb−1 of \( \sqrt{s}=8 \) TeV proton-proton collision data, ATLAS-CONF-2013-047, CERN, Geneva Switzerland (2013).
ATLAS collaboration, Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at \( \sqrt{s}=8 \) TeV with the ATLAS detector, Eur. Phys. J. C 75 (2015) 299 [Erratum ibid. C 75 (2015) 408] [arXiv:1502.01518] [INSPIRE].
CMS collaboration, Search for supersymmetry in hadronic final states with missing transverse energy using the variables α T and b-quark multiplicity in pp collisions at \( \sqrt{s}=8 \) TeV, Eur. Phys. J. C 73 (2013) 2568 [arXiv:1303.2985] [INSPIRE].
L. Randall and D. Tucker-Smith, Dijet searches for supersymmetry at the LHC, Phys. Rev. Lett. 101 (2008) 221803 [arXiv:0806.1049] [INSPIRE].
CMS collaboration, Search for supersymmetry in pp collisions at 7 TeV in events with jets and missing transverse energy, Phys. Lett. B 698 (2011) 196 [arXiv:1101.1628] [INSPIRE].
Open Access
This article is distributed under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits any use, distribution and reproduction in any medium, provided the original author(s) and source are credited.
Author information
Authors and Affiliations
Corresponding author
Additional information
ArXiv ePrint: 1512.02229
Rights and permissions
Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0), which permits use, duplication, adaptation, distribution, and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
About this article
Cite this article
Belyaev, A., Moretti, S., Nickel, K. et al. Hunting for neutral, long-lived exotica at the LHC using a missing transverse energy signature. J. High Energ. Phys. 2016, 18 (2016). https://doi.org/10.1007/JHEP03(2016)018
Received:
Revised:
Accepted:
Published:
DOI: https://doi.org/10.1007/JHEP03(2016)018