750 GeV diphotons and supersymmetric grand unification

Abstract

We investigate the 750 GeV diphoton excess in terms of supersymmetric models which preserve grand unification in the ultraviolet. We show that minimal extensions of the MSSM by a singlet and a vector-like 5-plet or 10-plet of SU(5) can explain the observed signal while remaining perturbative up to the GUT scale. Different from previous analyses we rely on light sfermions in the loops which -compared to the analog non-supersymmetric models -enhance the diphoton cross section by up to a factor of seven. While the resonance decay width is narrow, mass splitting of the scalar and pseudoscalar components may result in a double resonance. We perform a likelihood analysis on the ATLAS and CMS data to show that the significance of the diphoton excess increases from 3.3 σ (single narrow resonance) to 3.9 σ for the double resonance. We also provide signal predictions in other diboson channels to be tested at LHC-13.

750 GeV diphotons: implications for supersymmetric unification II

“…[7] but were studied for 4 of our 6 theories in ref. [8]. For each theory, the rates are computed for two cases corresponding to whether the supersymmetric mass terms of the vector matter, µ i , satisfy unified boundary conditions.…”

“…A sufficient diphoton signal results only if λ i take values close to the maximum allowed by perturbativity, and hence we take them to be determined by renormalization group flow, yielding a highly predictive theory. The diphoton resonance has been further explored in this minimal supersymmetric theory [8] as well as in other supersymmetric theories involving a singlet with vector matter in complete unified multiplets [9][10][11][12][13][14][15].…”

“…Next, let us take into account the effect of the scalar components of Φ i andΦ i , which is also investigated in ref. [8]. The trilinear couplings between the scalar components of S, Φ i andΦ i are given by…”

Diphoton resonance confronts dark matter

“…The production cross section for the diphoton resonance appears relatively large for given collider bounds from other related LHC searches [5,6]. The typical interpretation of diphoton excesses with a new scalar resonance calls for extra vector-like fermions with sizable Yukawa couplings to the resonance [5,6,[12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29]. In the case of a spin-2 resonance such as Kaluza-Klein graviton, a nontrivial positioning of SM particles in -1 -…”

Plateau inflation in R-parity violating MSSM

“…In order to explain the observed anisotropy of the cosmic microwave background (CMB) temperature at the super horizon scales [1] and at the same time the low value of the tensor-to-scalar ratio r < 0.07 [1,2] one requires an inflaton field with a plateau potential [3][4][5][6][7][8][9]. The other hint for a scalar field is the 750 GeV diphoton excess which may have been observed by ATLAS [10] and CMS [11] collaborations which has launched a large number of models which explain the 750 GeV diphoton resonance in the context of left-right models [12][13][14][15][16][17][18][19], Grand Unification [20][21][22] and supersymmetry (SUSY) [23][24][25][26][27][28] and other exotic models (reviewed in [29,30]). Cosmological implications of the 750 GeV scalar have been studied in [31][32][33][34][35].…”