Proton lifetime in minimal SUSY SU(5) in light of LHC results

K S Babu,Ilia Gogoladze,Cem Salih Ün

doi:10.1007/jhep02(2022)164

K S Babu, Ilia Gogoladze + Show 1 more

Open Access

https://doi.org/10.1007/jhep02(2022)164

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Abstract

We examine proton decay mediated by color-triplet Higgsinos in minimal supersymmetric SU(5) grand unified theory in light of the discovery of the Higgs boson and the absence of SUSY signals at the LHC. We pay special attention to various threshold effects arising from Planck-suppressed operators that affect the color-triplet Higgsino mass and also allow for correcting the wrong mass relations for the light fermions. Our analysis allows for a non-universal SUSY spectrum with the third family sfermions having a separate mass compared to the first two families. We identify the allowed parameter space of the model and show that the SUSY scalar masses are constrained by current limits from proton lifetime to be above 5 TeV, while the glunio, Wino and the Higgsinos may be within reach of the LHC. When the SUSY scalar masses are required to be ≤ 30 TeV, so that they are within reach of next generation collider experiments, we find that proton lifetime for the decay p → overline{nu} K+ is bounded by τ(p → overline{nu} K+) ≤ 1.1 × 1035 yrs.

Highlights

The color-triplet Higgsino, which is typically more dominant over the d = 6 gauge boson mediated proton decay rate, which scales as (MV )−4 with MV being the GUT scale mass of the gauge bosons
We identify the allowed parameter space of the model and show that the SUSY scalar masses are constrained by current limits from proton lifetime to be above 5 TeV, while the glunio, Wino and the Higgsinos may be within reach of the Large Hadron Collider (LHC)
When the SUSY scalar masses are required to be ≤ 30 TeV, so that they are within reach of generation collider experiments, we find that proton lifetime for the decay p → νK+ is bounded by τ (p → νK+) ≤ 1.1 × 1035 yrs

Summary

Correcting the wrong fermion mass relations

While staying within minimal SUSY SU(5), the wrong mass relations for the first two family fermions predicted by eq (2.12) can be corrected by allowing higher dimensional nonrenormalizable operators in the Yukawa superpotential. Such operators will be suppressed by a fundamental scale, presumably the Planck scale. It is interesting to note that the higher dimensional Yukawa operators of eq (3.1) can be generated by integrating out a 5 + 5∗ matter fields, as a simplest example, with mass of order the Planck scale Denoting these fields as χ + χ, the superpotential given by [25]. With this assumption, including eq (3.1), the mass matrices of down-type quarks and charged leptons take the form: Md = (f + f )vd,. It is this form of the effective baryon number violating operators that we shall use in our numerical study

Gravitational smearing of unified gauge coupling

Findings

Conclusion