Probing squeezed bino-slepton spectra with the Large Hadron Collider

Journal Article · Thu Oct 26 00:00:00 EDT 2017 · Physical Review D

DOI:https://doi.org/10.1103/PhysRevD.96.075037· OSTI ID:1598585

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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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)

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.

• Research Organization: Univ. of Hawaii, Honolulu, HI (United States)
• Sponsoring Organization: USDOE Office of Science (SC), High Energy Physics (HEP); National Science Foundation (NSF)
• Grant/Contract Number: SC0010504; FG02-13ER42020; SC0016013; SC007859; PHY-1521105; PHY-1250573; PHY-1417367; SC0010813
• OSTI ID: 1598585
• Alternate ID(s): OSTI ID: 1405048
• Journal Information: Physical Review D, Vol. 96, Issue 7; ISSN 2470-0010
• Publisher: American Physical Society (APS)
• Country of Publication: United States
• Language: English

Related Subjects

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