# Spin polarization independence of hard polarized fermion string scattering amplitudes

## TL;DR

This paper demonstrates that in high-energy limits, polarized fermion string scattering amplitudes are independent of spin polarization choices, extending Gross's conjecture to the fermionic sector and contrasting with field theory results.

## Contribution

It reveals a novel polarization independence property of fermionic string scattering amplitudes at all mass levels, extending theoretical understanding of high-energy string interactions.

## Key findings

- Polarized fermion string scattering amplitudes are polarization-independent at high energies.
- This extends Gross's conjecture to include fermionic sectors.
- The property contrasts with polarization dependence in fermionic field theory scatterings.

## Abstract

We calculate a class of polarized fermion string scattering amplitudes (PFSSA) at arbitrary mass levels. We discover that, in the hard scattering limit, the functional forms of the non-vanishing PFSSA at each fixed mass level are independent of the choices of spin polarizations. This result justifies and extends Gross conjecture on high energy string scattering amplitudes to the fermionic sector. In addition, this peculiar property of hard PFSSA is to be compared with the usual spin polarization dependence of the hard polarized fermion field theory scatterings.