[Paper Review] Dark matter and Inflation in PeV scale SUSY

Girish Kumar Chakravarty, Najimuddin Khan+1 more|arXiv (Cornell University)|Jul 12, 2017

Computational Physics and Python Applications3 citations

TL;DR

This paper proposes a unified supersymmetric model at the PeV scale that simultaneously explains cosmic inflation and the observed PeV neutrinos at IceCube. Using a no-scale Kähler potential and D-term inflation via Higgs-sneutrino coupling, it achieves Starobinsky-like inflation and generates a 6 PeV bino-like dark matter particle that accounts for ~11% of the relic density; its decay into neutrinos reproduces the IceCube flux, while gauge unification and a 125 GeV Higgs are preserved via RGE running from GUT-scale SUSY breaking.

ABSTRACT

We construct an unified model of inflation and PeV dark matter which is consistent with the CMB observations and can explain the PeV neutrinos at IceCube. A no-scale K\ahler potential and an appropriate choice of gauge kinetic function in MSSM superfields can result in Starobinsky like Higgs-sneutrino plateau inflation from $D$-term potential. The SUSY breaking at the PeV scale is achieved through the Polonyi field. This sets the scales $m_0, m_{\frac{1}{2}}, A_0$ at the GUT scale in terms of the parameters of the theory. The low energy (PeV scale) spectrum is obtained by running the RGEs. We show that the $\sim$125 GeV higgs and the gauge coupling unification can be achieved in this model. The $6$ PeV bino-type dark matter is a subdominant fraction ($\sim 11\%$) of the relic density and its decay gives the PeV scale neutrino flux observed at IceCube by choosing the couplings of the $R$-parity violating operators.

Motivation & Objective

• To unify inflation and PeV-scale dark matter within a single supersymmetric framework consistent with CMB observations.
• To explain the origin of the 125 GeV Higgs boson and gauge coupling unification in a model with high-scale SUSY breaking.
• To account for the PeV neutrino flux observed by IceCube through the decay of a heavy bino-like dark matter particle.
• To realize D-term inflation with a Starobinsky-like plateau using Higgs and sneutrino fields in a no-scale MSSM setup.
• To achieve consistent low-energy spectra via RGE evolution from GUT-scale boundary conditions set by Polonyi-mediated SUSY breaking.

Proposed method

• Employing a no-scale Kähler potential and a specific gauge kinetic function in the MSSM superfields to generate a flat D-term potential for inflation.
• Utilizing the Polonyi field to break supersymmetry at the PeV scale, setting the GUT-scale boundary conditions for m₀, m₁/₂, and A₀.
• Running the renormalization group equations (RGEs) from the GUT scale down to the electroweak scale to determine the low-energy spectrum.
• Introducing R-parity violating operators with tuned couplings to allow the 6 PeV bino-like dark matter to decay into neutrinos, matching the IceCube flux.
• Constructing a Higgs-sneutrino hybrid potential that supports a Starobinsky-like inflationary plateau via D-term contributions.
• Ensuring consistency with CMB observations by verifying the scalar spectral index and tensor-to-scalar ratio in the inflationary model.

Experimental results

Research questions

• RQ1 Can a single PeV-scale SUSY model simultaneously account for successful D-term inflation and the PeV neutrino flux observed by IceCube?
• RQ2 How can the 125 GeV Higgs mass and gauge coupling unification be achieved in a model with high-scale SUSY breaking at the PeV scale?
• RQ3 What role does the Polonyi field play in setting the GUT-scale boundary conditions for soft masses in this unified framework?
• RQ4 How does the inclusion of R-parity violating operators enable a heavy bino-like dark matter to decay into PeV neutrinos while remaining consistent with relic density constraints?
• RQ5 To what extent can the no-scale Kähler potential and D-term potential jointly generate a Starobinsky-like inflationary plateau?

Key findings

• The model realizes a Starobinsky-like inflationary plateau through a D-term potential involving the Higgs and sneutrino fields, consistent with CMB observations.
• The 125 GeV Higgs boson mass is successfully reproduced via RGE evolution from GUT-scale boundary conditions set by PeV-scale SUSY breaking.
• Gauge coupling unification is preserved in the model, indicating consistency with minimal supersymmetric grand unification.
• The 6 PeV bino-like dark matter particle constitutes approximately 11% of the total relic density, consistent with cosmological constraints.
• The decay of this dark matter particle into neutrinos, mediated by R-parity violating operators, reproduces the observed PeV neutrino flux at IceCube.
• The model achieves a consistent low-energy spectrum through RGE running, with all parameters determined from the underlying theory at the GUT scale.