Compton Scattering from the Deuteron below Pion-Production Threshold

TL;DR

This study reports new measurements of photon-deuteron elastic scattering above 70 MeV, refining nucleon polarizability values and confirming consistency with previous data through Chiral Effective Field Theory analysis.

Contribution

It provides the first measurements above 100 MeV and offers refined values for nucleon isoscalar polarizabilities using new experimental data and theoretical analysis.

Findings

New differential cross section data between 70 and 112 MeV

Refined values for nucleon polarizabilities: _s and _b

Data consistent with previous measurements and theoretical models

Abstract

Differential cross sections for elastic scattering of photons from the deuteron have recently been measured at the Tagged-Photon Facility at the MAX IV Laboratory in Lund, Sweden. These first new measurements in more than a decade further constrain the isoscalar electromagnetic polarizabilities of the nucleon and provide the first-ever results above 100 MeV, where the sensitivity to the polarizabilities is increased. We add 23 points between 70 and 112 MeV, at angles 60deg, 120deg and 150deg. Analysis of these data using a Chiral Effective Field Theory indicates that the cross sections are both self-consistent and consistent with previous measurements. Extracted values of \alpha_s = [12.1 +/- 0.8(stat) +/- 0.2(BSR) +/- 0.8(th)] X 10^{-4} fm^3 and \beta_s = [2.4 +/- 0.8(stat) +/- 0.2(BSR) +/- 0.8(th)] X 10^{-4} fm^3 are obtained from a fit to these 23 new data points. This paper presents in detail the experimental conditions and the data analysis used to extract the cross sections.