Soft behavior of a closed massless state in superstring and universality of the soft behavior of the dilaton

TY - JOUR

T1 - Soft behavior of a closed massless state in superstring and universality of the soft behavior of the dilaton

AU - di Vecchia, Paolo

AU - Marotta, Raffaele

AU - Mojaza, Matin

PY - 2016/12/1

Y1 - 2016/12/1

N2 - We consider the tree-level scattering amplitudes in the NS-NS (Neveu-Schwarz) massless sector of closed superstrings in the case where one external state becomes soft. We compute the amplitudes generically for any number of dimensions and any number and kind of the massless closed states through the subsubleading order in the soft expansion. We show that, when the soft state is a graviton or a dilaton, the full result can be expressed as a soft theorem factorizing the amplitude in a soft and a hard part. This behavior is similar to what has previously been observed in field theory and in the bosonic string. Differently from the bosonic string, the supersymmetric soft theorem for the graviton has no string corrections at subsubleading order. The dilaton soft theorem, on the other hand, is found to be universally free of string corrections in any string theory.

AB - We consider the tree-level scattering amplitudes in the NS-NS (Neveu-Schwarz) massless sector of closed superstrings in the case where one external state becomes soft. We compute the amplitudes generically for any number of dimensions and any number and kind of the massless closed states through the subsubleading order in the soft expansion. We show that, when the soft state is a graviton or a dilaton, the full result can be expressed as a soft theorem factorizing the amplitude in a soft and a hard part. This behavior is similar to what has previously been observed in field theory and in the bosonic string. Differently from the bosonic string, the supersymmetric soft theorem for the graviton has no string corrections at subsubleading order. The dilaton soft theorem, on the other hand, is found to be universally free of string corrections in any string theory.

U2 - 10.1007/JHEP12(2016)020

DO - 10.1007/JHEP12(2016)020

M3 - Journal article

SN - 1126-6708

VL - 2016

SP - 20

EP - 45

JO - Journal of High Energy Physics (Online)

JF - Journal of High Energy Physics (Online)

IS - 020

M1 - 020

ER -