Natural SUSY with a bino- or wino-like LSP

Journal Article · Wed Apr 08 00:00:00 EDT 2015 · Physical Review. D, Particles, Fields, Gravitation and Cosmology

DOI:https://doi.org/10.1103/PhysRevD.91.075005· OSTI ID:1598670

Baer, Howard ^[1]; Barger, Vernon ^[2]; Huang, Peisi ^[3]; Mickelson, Dan ^[4]; Padeffke-Kirkland, Maren ^[4]; Tata, Xerxes ^[5]

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1. Univ. of Oklahoma, Norman, OK (United States); Univ. of Minnesota, Minneapolis, MN (United States)
2. Univ. of Wisconsin, Madison, WI (United States)
3. Argonne National Lab. (ANL), Argonne, IL (United States); Univ. of Chicago, IL (United States). Enrico Fermi Inst.
4. Univ. of Oklahoma, Norman, OK (United States)
5. Univ. of Hawaii, Honolulu, HI (United States)

In natural SUSY models higgsinos are always light because μ² cannot be much larger than M$$2\atop{Z}$$, while squarks and gluinos may be very heavy. Unless gluinos are discovered at LHC13, the commonly assumed unification of gaugino mass parameters will imply correspondingly heavy winos and binos, resulting in a higgsino-like LSP and small inter-higgsino mass splittings. The small visible energy release in higgsino decays makes their pair production difficult to detect at the LHC. Relaxing gaugino mass universality allows for relatively light winos and binos without violating LHC gluino mass bounds and without affecting naturalness. In the case where the bino mass M₁≲ μ, then one obtains a mixed bino-higgsino LSP with instead sizable w₁-z₁ and z₂-z₁ mass gaps. The thermal neutralino abundance can match the measured dark matter density in contrast to models with a higgsino-like LSP where WIMPs (weakly interacting massive particles) are underproduced by factors of 10-15. If instead M₂≲ μ, then one obtains a mixed wino-higgsino LSP with large z₂-z₁ but small w₁-z₁ mass gaps with still an under-abundance of thermally-produced WIMPs. Portions of the light wino parameter space may already be excluded by the IceCube upper bound on the spin-dependent neutralino-nucleon cross section. We discuss dark matter detection in other direct and indirect detection experiments and caution that the bounds from these must be interpreted with care. Finally, we show that LHC13 experiments should be able to probe these non-universal mass scenarios via a variety of channels including multi-lepton + E$$miss\atop{T}$$ events, WZ+ E$$miss\atop{T}$$ events, Wh+ E$$miss\atop{T}$$ events and W± W± + E$$miss\atop{T}$$ events from electroweak chargino and neutralino production.

• Research Organization: Univ. of Hawaii, Honolulu, HI (United States)
• Sponsoring Organization: USDOE Office of Science (SC), High Energy Physics (HEP)
• Grant/Contract Number: SC0010504
• OSTI ID: 1598670
• Alternate ID(s): OSTI ID: 1179366
• Journal Information: Physical Review. D, Particles, Fields, Gravitation and Cosmology, Vol. 91, Issue 7; ISSN 1550-7998
• Publisher: American Physical Society (APS)
• Country of Publication: United States
• Language: English

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