Measurement of the two photon exchange on the neutron with Super BigBite spectrometer in Hall A at Jefferson Lab

The nTPE experiment which will run in January of 2022 in Jefferson La Hall A

aims to measure the two-photon exchange contribution in elastic electron-neutron

scattering at a four-momentum transfer $Q^2$~= 4.0 GeV$^2$.

The proposed experiment will measure the ratio of quasi-elastic $en$ over $ep$

cross sections off deuterium at the aforementioned value of $Q^2$ and two beam energies,

4.03 and 6.00 GeV.

The experimental setup is composed of the BigBite (BB) spectrometer to detect

the scattered electrons and  Super-BigBite (SBS) to detect the protons and neutrons.

This set of measurements will give an experimental estimation of the neutron Rosenbluth slope.

The comparison between the experimental Rosenbluth slope and the current estimation of $G_E^n$

will provide an experimental estimation of the two-photon exchange contribution.

In this presentation we will present the nTPE experiment with an emphasis

on the experimental analysis method and the progress of the data analysis.