Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: S-matrix bootstrap for resonances   We study the $2\rightarrow2$ $S$-matrix element of a generic, gapped and
Lorentz invariant QFT in $d=1+1$ space time dimensions. We derive an analytical
bound on the coupling of the asymptotic states to unstable particles (a.k.a.
resonances) and its physical implications. This is achieved by exploiting the
connection between the S-matrix phase-shift and the roots of the S-matrix in
the physical sheet. We also develop a numerical framework to recover the
analytical bound as a solution to a numerical optimization problem. This later
approach can be generalized to $d=3+1$ spacetime dimensions.

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The categories of this paper are: nucl-th
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The categories of this paper are: econ
33
The categories of this paper are: plasm-ph
24
The categories of this paper are: dg-ga
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The categories of this paper are: acc-phys
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The categories of this paper are: adap-org
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The categories of this paper are: cs
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The categories of this paper are: cond-mat
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The categories of this paper are: alg-geom
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The categories of this paper are: ao-sci
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The categories of this paper are: cmp-lg
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The categories of this paper are: chem-ph
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The categories of this paper are: supr-con
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The categories of this paper are: quant-ph
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The categories of this paper are: q-alg
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The categories of this paper are: hep-lat