QCD-Compatible Supermassive Inert Top-Down Holographic Mesinos at Intermediate Coupling

TL;DR

This paper presents a UV-complete type IIA string dual model of thermal QCD at intermediate coupling, where mesinos are heavier and non-interacting with mesons, resolving a longstanding contradiction in holographic QCD models.

Contribution

It introduces a new holographic dual at intermediate coupling with heavier, non-interacting mesinos and derives a large-N enhancement of the KK mass scale, improving realism of QCD holographic models.

Findings

Mesinos are much heavier than mesons in the model.

Mesino-mesino-single meson interactions vanish.

Large-N enhancement of the KK mass scale is derived.

Abstract

A longstanding problem with the popular Sakai-Sugimoto holographic dual of thermal QCD is that the "mesinos", the (non-supersymmetric) fermionic partners of the mesons, are nearly isospectral with mesons and have an unsuppressed mesino-meson interaction, both being in contradiction with actual QCD. We solve this problem in a UV-complete (and ${\it different}$) type IIA string dual ${\it at\ intermediate\ coupling}$ of realistic thermal QCD, in which the mesinos are shown to be much heavier than and non-interacting with mesons (the wave-function/mass/interaction terms receiving no ${\cal M}$-theory ${\cal O}(R^4)$ corrections). In particular we derive a large-$N$ enhancement of the KK mass scale $M_{KK}$ (from $M_{KK}$ to $M_{KK}^{\rm eff}\sim N^{1 + \frac{1}{{\cal O}(1)}}M_{KK}$) arising from the construction of the type IIA mirror \cite{MQGP} of the type IIB dual \cite{metrics} of thermal QCD-like theories, as well as the generation of a one-parameter family of $M_{KK}$-independent mass scale at ${\cal O}(R^4)$ in the ${\cal M}$-theory uplift \cite{OR4} wherein the parameter can be made appropriately large. We also show that the mesino-mesino-single-($\rho/\pi$)meson interactions, vanish identically in the aforementioned type IIA holographic dual.