Experimental signatures of an alternative supersymmetry

TL;DR

The paper tackles the lack of evidence for conventional SUSY by proposing a radical alternative in which primitive Spin(10) fields reorganize in the early universe to yield a Lorentz-invariant vacuum with two scalar-boson sectors, $\phi$ and $\varphi$. By starting from representations $32=16+\overline{16}$ and $10=5+\overline{5}$ and constructing amplitude modes through a two-step transformation, it derives a scenario in which sfermions in the $\varphi$ sector lead to dramatically different collider phenomenology while preserving Higgs mass protection and gauge unification. In this scenario, the lowest-mass $\varphi$ state serves as a dark matter candidate (a higgson) near $70$ GeV, and squark/gluino decays are forbidden, yielding stable R-hadrons and novel search channels discussed in companion works. The paper then outlines experimental prospects at the HL-LHC and future colliders, arguing that this alternative SUSY phenomenology can both explain past non-observations and guide future experimental efforts. Overall, it presents a coherent, testable framework that preserves key SUSY advantages while predicting distinctive DM and collider signatures.

Abstract

There are at least three physical arguments for some form of supersymmetry, based on experiment and observation, but conventional supersymmetry (SUSY) has not been observed up to surprisingly high experimental limits. Here we consider a radically different version, with initial bosonic fields in $32=16+\overline{16}$ (primitive sfermion) and $10=5+\overline{5}$ (primitive Higgs-related) representations of Spin(10) which do not satisfy Lorentz invariance. In the extremely early universe there is a reformation of these fields to achieve a stable Lorentz-invariant vacuum with two varieties of physical scalar-boson fields -- standard fields $φ$ and fields $\varphi$ of a new kind. There are then two possible scenarios: If sfermion fields are in the $φ$ sector, the present description leads back to standard physics, including the standard model, SO(10) grand unification, and conventional SUSY. But if sfermion fields belong to the $\varphi$ sector, the predictions for production and decays of sparticles are dramatically different, potentially explaining their previous nonobservation. The masses of scalar bosons are still protected from enormous radiative corrections, gauge unification can be achieved, and there is a lowest-mass superpartner as a dark matter candidate -- although it is presumed to be less abundant than the $\approx 70$ GeV candidate we introduced earlier in this same general context. Calculations by Shankar, Tallman, and Martinez in separate papers explore the possibilities for detection in future colliders, beginning with the high-luminosity LHC.

Figures (2)

• Figure 1: Left panel: Representative diagrams for contributions of fermion and sfermions -- in this case top quark and top squarks -- to quantum corrections of Higgs mass-squared. According to (\ref{['eq50x']}), the unconventional sfermions defined here will still provide the standard supersymmetric cancellation of quadratric divergences, provided that all sfermions have masses not far above a few TeV. Examination of the relevant diagrams indicates that this cancellation holds for all processes in higher-order diagrams, since fermions and sfermions are coupled to both Higgs bosons and gauge bosons. Right panel: Many sfermion production processes are still allowed in the present scenario -- for example, production of squarks by direct gluon fusion, shown here.
• Figure 2: Left panel: Conventional sfermion decay processes, like the one shown here, do not exist in the present scenario 2, because each vertex must involve two sfermion fields and two other bosonic fields. The conventional schemes for detecting sfermions rely on their being produced in collisions through processes that largely do not exist in the present scenario, and then, more importantly, decaying through processes that are entirely disallowed. This implies that new detection schemes are required, and that squarks with masses $\sim$ 1 TeV may exist even though they have not previously been identified. Right panel: Gluino decay processes, like the one shown here, do not exist, because a decay would require a squark-quark vertex to conserve R-parity and color charge, with first-order squark vertices not allowed in the present scenario.