Three-nucleon force contribution to the deuteron channel in $(d,p)$ reactions

TL;DR

This paper investigates how three-nucleon forces influence deuteron-target interactions in (d,p) reactions, revealing strong sensitivity to the force model and the optical potential assumptions, affecting reaction cross section calculations.

Contribution

It provides the first detailed analysis of three-nucleon force effects on the deuteron channel in (d,p) reactions using chiral EFT interactions within the ADWA framework.

Findings

Deuteron-target potential is highly sensitive to 3N force models.

Using Watanabe folding reduces the sensitivity to 3N forces.

3N force effects on cross sections depend on optical potential assumptions.

Abstract

The contribution of a three-nucleon (3N) force, acting between the neutron and proton in the incoming deuteron with a target nucleon, to the deuteron-target potential in the entrance channel of the $A(d,p)B$ reaction has been calculated within the adiabatic distorted wave approximation (ADWA). Four different 3N interaction sets from local chiral effective field theory ($\chi$EFT) at next-to-next-to-leading order (N2LO) were used. Strong sensitivity of the adiabatic deuteron-target potential to the choice of the 3N force format has been found, which originates from the enhanced sensitivity to the short-range physics of nucleon-nucleon (NN) and 3N interactions in the ADWA. Such a sensitivity is reduced when a Watanabe folding model is used to generate $d$-$A$ potential instead of ADWA. The impact of the 3N force contribution on $(d,p)$ cross sections depends on assumptions made about the $p$-$A$ and $n$-$A$ optical potentials used to calculate the distorted $d$-$A$ potential in the entrance channel. It is different for local and nonlocal optical potentials and depends on whether the induced three-body force arising due to neglect of target excitations is included or not.