Title: Probing squeezed bino-slepton spectra with the Large Hadron Collider

Abstract

In this study, we consider a minimal supersymmetric Standard Model scenario in which the only light superparticles are a binolike dark matter candidate and a nearly degenerate slepton. It is notoriously difficult to probe this scenario at the Large Hadron Collider (LHC), because the slepton pair-production process yields a final state with soft leptons and small missing transverse energy. We study this scenario in the region of parameter space where the mass difference between the lightest neutralino and the lightest slepton ( $\mathrm{\Delta }m$) is $\lesssim 60\mathrm{GeV}$, focusing on the process in which an additional radiated jet provides a transverse boost to the slepton pair. We then utilize the angular separation of the leptons from each other and from the missing transverse energy, as well as the angular separation between the jet and the missing transverse energy, to distinguish signal from background events. We also use the reconstructed ditau mass, the $\cos {\theta }_{{\ell }_1{\ell }_2}^{*}$ variable, and for larger $\mathrm{\Delta }m$, a lower bound on the lepton $p_T$. These cuts can dramatically improve both signal sensitivity and the signal-to-background ratio, permitting discovery at the LHC with reasonable integrated luminosity over the interesting region of parameter space. Using our search strategy the LHC will be able to exclude $m_{\tilde{\mu }}\approx 200\mathrm{GeV}$ for $\mathrm{\Delta }m\lesssim 60\mathrm{GeV}$ at $1.5–3\sigma$ with $1000{\mathrm{fb}}^{-1}$ of integrated luminosity. Although we focus on a particular model, the results generalize to a variety of scenarios in which the dark matter and a leptonic partner are nearly degenerate in mass, and especially to scenarios featuring a scalar mediator.

Authors:

Dutta, Bhaskar ^[1]; Fantahun, Kebur ^[2]; Fernando, Ashen ^[2]; Ghosh, Tathagata ^[3]; Kumar, Jason ^[4]; Sandick, Pearl ^[5]; Stengel, Patrick ^[6]; Walker, Joel W. ^[2]

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+ Show Author Affiliations

1. Texas A & M Univ., College Station, TX (United States)
2. Sam Houston State Univ., Huntsville, TX (United States)
3. Oklahoma State Univ., Stillwater, OK (United States)
4. Univ. of Hawaii, Honolulu, HI (United States)
5. Univ. of Utah, Salt Lake City, UT (United States)
6. Univ. of Michigan, Ann Arbor, MI (United States)

Publication Date:

Thu Oct 26 00:00:00 EDT 2017

Research Org.:

Univ. of Hawaii, Honolulu, HI (United States)

Sponsoring Org.:

USDOE Office of Science (SC), High Energy Physics (HEP); National Science Foundation (NSF)

OSTI Identifier:

1598585

Alternate Identifier(s):

OSTI ID: 1405048

Grant/Contract Number:  

SC0010504; FG02-13ER42020; SC0016013; SC007859; PHY-1521105; PHY-1250573; PHY-1417367; SC0010813

Resource Type:

Accepted Manuscript

Journal Name:

Physical Review D

Additional Journal Information:

Journal Volume: 96; Journal Issue: 7; Journal ID: ISSN 2470-0010

Publisher:

American Physical Society (APS)

Country of Publication:

United States

Language:

English

Subject:

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; Extensions of fermion sector; Extensions of gauge sector; Particle decays; Supersymmetry