750 GeV diphotons from supersymmetry with Dirac gauginos

Abstract

Motivated by the recent excess in the diphoton invariant mass near 750 GeV, we explore a supersymmetric extension of the Standard Model that includes the minimal set of superpartners as well as additional Dirac partner chiral superfields in the adjoint representation for each gauge group. The bino partner pseudoscalar is identified as the 750 GeV resonance, while superpotential interactions between it and the gluino (wino) partners yield production via gluon fusion (decay to photon pairs) at one-loop. The gauginos and these additional adjoint superpartners are married by a Dirac mass and must also have Majorana masses. While a large wino partner Majorana mass is necessary to explain the excess, the gluino can be approximately Dirac-like, providing benefits consistent with being both "supersoft" (loop corrections to the scalar masses from Dirac gauginos are free of logarithmic enhancements) and "supersafe" (the experimental limits on the squark/gluino masses can be relaxed due to the reduced production rate). Consistency with the measured Standard Model-like Higgs boson mass is imposed, and a numerical exploration of the parameter space is provided. Models that can account for the diphoton excess are additionally characterized by having couplings that can remain perturbative up to very high scales, while remaining consistent with experimental constraints, the Higgs boson mass, and an electroweak scale which is not excessively fine-tuned.

Leading two-loop corrections to the Higgs boson masses in SUSY models with Dirac gauginos

“…To have renormalisable Yukawa couplings between the octet and the MSSM fields we would need to add new coloured states (such as a vector-like top). However, in the most general version of the MDGSSM there could also be terms that violate the above assumption -which have only recently attracted attention [17,71] -namely couplings between the singlet and the octet of the form…”

A supersymmetric theory of baryogenesis and sterile sneutrino dark matter from B mesons

“…If no other source of mass for gauginos is present, this implies that there must exist a hierarchy (c 1 /Λ 1 )/(c 2,3 /Λ 2,3 ) 10 −3 . Such hierarchy can be explained either by invoking some tuning of the c i coefficients or by allowing for at least two separate sources of SUSY breaking [29] so that Λ 1 Λ 2,3 .…”

Precision tools and models to narrow in on the 750 GeV diphoton resonance

“…We find a similar behaviour, but still there are several GeV difference between both calculations. For κ 10 = 0.8 and X t = 4, the point would be within the interesting range for m h = [123,127] GeV, while the more sophisticated calculation predicts a mass below 120 GeV. Thus, the assumed uncertainty of 2 GeV in Ref.…”

“…[180] and we fixed X κ10 = 0. The lines are the results from SPheno, while the green and red shades areas are the ranges of κ 10 which predict m h = [123,127] GeV according to Ref. [180].…”