Natural supersymmetry: status and prospects
Dept. of Physics and Astronomy, University of Hawaii,
HI 96822, USA
a e-mail: firstname.lastname@example.org
Accepted: 14 October 2020
Published online: 14 December 2020
The realization that supersymmetry (SUSY), if softly broken at the weak scale, can stabilize the Higgs sector led many authors to explore the role it may play in particle physics. It was widely anticipated that superpartners would reveal themselves once the TeV scale was probed in high energy collisions. Experiments at the LHC have not yet revealed any sign for direct production of superpartners, or for any other physics beyond the Standard Model. This has led to some authors to question whether weak scale SUSY has a role to play in stabilizing the Higgs sector, and to seek alternate mechanisms for stabilizing the weak scale. We reevaluate the early arguments that led to the expectations for light superpartners, and show that SUSY models with just the minimal particle content may well be consistent with LHC (and other) data and simultaneously serve to stabilize the Higgs sector, if model parameters generally regarded as independent turned out to be appropriately correlated. In our view, it would be premature to ignore this possibility, given that we do not understand the underlying mechanism of SUSY breaking. We advocate using the electroweak scale quantity, ΔEW, to determine whether a given SUSY spectrum might arise from a theory with low fine-tuning, even when the parameters correlations mentioned above are present. We find that (modulo technical caveats) all such models contain light higgsinos and that this leads to the possibility of new strategies for searching for SUSY. We discuss phenomenological implications of these models for SUSY searches at the LHC and its luminosity and energy upgrades, as well as at future electron-positron colliders. We conclude that natural SUSY, defined as no worse than a part in 30 fine-tuning, will not escape detection at a pp collider operating at 27 TeV and an integrated luminosity of 15 ab−1, or at an electron-positron collider with a centre-of-mass energy of 600 GeV.
© EDP Sciences, Springer-Verlag GmbH Germany, part of Springer Nature, 2020