Studying the Strangeness $D$-Term in Hall C via Exclusive $\ddot{I}•$ Electroproduction

Abstract

We propose a measurement of exclusive electroproduction of $\ddot{I}•$ mesons near threshold in Hall C. We will measure the |t|-dependence of the exclusive $\ddot{I}•$ electroproduction cross section, which has recently been proposed as an observable sensitive to the strangeness $D$-term. The contribution of strangeness to the total $D$-term is presently unknown, with different arguments favoring $D_s$ being large, being small, or even having opposite sign from the total $D$-term. Our exploratory measurement is designed to distinguish between these hypotheses. If $D_s$ turns out to be small, $\ddot{I}•$ electroproduction can be used to study the gluon $D$-term. In addition, this dataset will allow us to perform measurements of other exclusive meson final states, including the first measurement of $\hat{I}{\cdot }^{\prime }$ electroproduction and multi-differential measurements of $\hat{I}\cdot$ and $\ddot{I}‰$ electroproduction.

Proposal submitted to Jefferson Lab PAC 53 On ArXiv, v1 is the letter-of-intent, v2 is the approved proposal