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arXiv · 2203.11950

Bootstrapping Pions at Large $N$

Jan Albert·Leonardo Rastelli
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Abstract

We revisit from a modern bootstrap perspective the longstanding problem of solving QCD in the large $N$ limit. We derive universal bounds on the effective field theory of massless pions by imposing the full set of positivity constraints that follow from $2 \to 2$ scattering. Some features of our exclusion plots have intriguing connections with hadronic phenomenology. The exclusion boundary exhibits a sharp kink, raising the tantalizing scenario that large $N$ QCD may sit at this kink. We critically examine this possibility, developing in the process a partial analytic understanding of the geometry of the bounds.

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Jan Albert, Leonardo Rastelli. 2022-03-22. Bootstrapping Pions at Large $N$. https://doi.org/10.1007/jhep08(2022)151

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