Spinning-off stringy electro-magnetic memories

TL;DR

This paper extends string corrections to electromagnetic memory effects in Type I superstring theory, incorporating spin effects, non-perturbative corrections, and potential observable signals in semi-classical states.

Contribution

It generalizes EM memory corrections to Type I superstrings, including spin effects and non-perturbative $\alpha'\$ corrections, and discusses potential experimental detection.

Findings

Corrections are non-perturbative in $\alpha'\$ and decay as 1/R at large distances.

Spin N states induce N derivatives on the amplitude with respect to retarded time.

Possible detection of string memory signals in semi-classical coherent states.

Abstract

We extend and generalise the string corrections to the EM memory to the Type I superstring including spin effects. Very much as in the simpler bosonic string context, the relevant corrections are non-perturbative in $\alpha'$, slowly decaying (as $1/R$) at large distances and modulated in retarded time $u=t-R$. For spin $N$ states in the first Regge trajectory they entail a sequence of $N$ derivatives wrt $u$ on the `parent' $N=0$ amplitude. We also briefly discuss how to include loop effects, that broaden and shift the string resonances, and how to modify our analysis for macroscopic semi-classical quasi-BPS coherent states, whose collisions may lead to detectable string memory signals in viable Type I models.