A new (string motivated) approach to the little hierarchy problem

TL;DR

This paper proposes a string-inspired approach where gravitino masses of 10-50 TeV naturally enable electroweak symmetry breaking without fine-tuning, addressing the little hierarchy problem.

Contribution

It introduces a new mechanism linking high gravitino masses to successful EWSB without cancellations, grounded in string/M-theory compactifications.

Findings

EWSB occurs naturally with gravitino mass >30 TeV

Higgs vev and $ppa$ are of order TeV despite heavy scalars

Addresses cosmological moduli and gravitino problems

Abstract

We point out that in theories where the gravitino mass, $M_{3/2}$, is in the range (10-50)TeV, with soft-breaking scalar masses and trilinear couplings of the same order, there exists a robust region of parameter space where the conditions for electroweak symmetry breaking (EWSB) are satisfied without large imposed cancellations. Compactified string/M-theory with stabilized moduli that satisfy cosmological constraints generically require a gravitino mass greater than about 30 TeV and provide the natural explanation for this phenomenon. We find that even though scalar masses and trilinear couplings (and the soft-breaking $B$ parameter) are of order (10-50)TeV, the Higgs vev takes its expected value and the $\mu$ parameter is naturally of order a TeV. The mechanism provides a natural solution to the cosmological moduli and gravitino problems with EWSB.