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arXiv · 1802.04021

Field theoretical derivation of Lüscher's formula and calculation of finite volume form factors

Zoltán Bajnok·János Balog·Márton Lájer·Chao Wu
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Abstract

We initiate a systematic method to calculate both the finite volume energy levels and form factors from the momentum space finite volume two-point function. By expanding the two point function in the volume we extracted the leading exponential volume correction both to the energy of a moving particle state and to the simplest non-diagonal form factor. The form factor corrections are given in terms of a regularized infinite volume 3-particle form factor and terms related to the Lüsher correction of the momentum quantization. We tested these results against second order Lagrangian and Hamiltonian perturbation theory in the sinh-Gordon theory and we obtained perfect agreement.

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Zoltán Bajnok, János Balog, Márton Lájer, Chao Wu. 2018-07-10. Field theoretical derivation of Lüscher's formula and calculation of finite volume form factors. https://doi.org/10.1007/jhep07(2018)174

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