A New Structure in the Deuteron

TL;DR

This paper proposes a new perspective on the deuteron structure, suggesting the existence of an 'incomplete' P-state component observable at high momenta, which could reveal non-nucleonic configurations through specific experimental signatures.

Contribution

It introduces a novel light-front framework considering the deuteron as a pseudo-vector system, predicting observable signatures of non-nucleonic components in high-energy electro-disintegration experiments.

Findings

Identification of a new 'incomplete' P-state structure in the deuteron.

Predicted angular anisotropy in nucleon momentum distribution.

Enhanced tensor polarization at large internal momenta.

Abstract

We demonstrate that a paradigm shift from considering the deuteron as a system of bound proton and neutron to considering it as a pseudo-vector system in which we observe proton and neutron, results in a possibility of probing a new "incomplete" P-state like structure on the light-front (LF), at extremely large internal momenta, which can be achieved in high energy transfer electro-disintegration of the deuteron. Investigating the deuteron on the light-front, where the vacuum-fluctuations are suppressed, we found that this new structure, together with conventional S- and D- states, is a leading order in transferred energy of the reaction, thus it is not suppressed on the light-front.The incompleteness of the observed P-state results in a violation of angular condition which can happen only if deuteron contains non-nucleonic structures such as $\Delta$$\Delta$, $N^*N$ or hidden color components. We demonstrate that experimentally verifiable signatures of "incomplete" P-states are angular anisotropy of LF momentum distribution of the nucleon in the deuteron as well as an enhancement of the tensor polarization strength beyond the S- and D- wave predictions at large internal momenta in the deuteron.