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arXiv · hep-th/9709019

Multiloop $Φ^3$ Amplitudes from Bosonic String Theory

Kaj Roland·Haru-Tada Sato
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Abstract

We show how the multiloop amplitudes of $Φ^3$ theory (in the worldline formulation of Schmidt and Schubert) are recovered from the N-tachyon $(h+1)$-loop amplitude in bosonic string theory in the $α' \to 0$ limit, if one keeps the tachyon coupling constant fixed. In this limit the integral over string moduli space receives contributions only from those corners where the world-sheet resembles a $Φ^3$ particle diagram. Technical issues involved are a proper choice of local world-sheet coordinates, needed to take the string amplitudes off-shell, and a formal procedure for introducing a free mass parameter $M^2$ instead of the tachyonic value $-4/α'$.

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Kaj Roland, Haru-Tada Sato. 1997-09-02. Multiloop $Φ^3$ Amplitudes from Bosonic String Theory. https://doi.org/10.1016/s0550-3213(97)00822-5

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