Nucleon Polarisabilities from Compton Scattering on the Deuteron

• Published in: arXiv.org
• Main Authors: Griesshammer, Harald W, Gautam Rupak
• Format: Paper
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 29.12.2000
• Subjects: Elastic scattering; Field theory; Parameter uncertainty; Pions
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.0012096

An analytic calculation of the differential cross section for elastic Compton scattering on the deuteron at photon energies \omega in the range of 25-50 MeV is presented to next-to-next-to-leading order, i.e. to an accuracy of \sim 3%. The calculation is model-independent and performed in the low energy nuclear Effective Field Theory without dynamical pions. The iso-scalar, scalar electric and magnetic nucleon polarisabilities \alpha_0 and \beta_0 enter as free parameters with a theoretical uncertainty of about 20%. Using data at \(\omega_{Lab}=49 MeV\) we find \(\alpha_0=8.4\pm 3.0(exp)\pm 1.7(theor)\), \(\beta_0=8.9\pm 3.9(exp)\pm 1.8(theor)\), each in units of \(10^{-4} fm^3\). With the experimental constraint for the iso-scalar Baldin sum rule, \(\alpha_0=7.2\pm 2.1(exp)\pm 1.6(theor)\), \(\beta_0=6.9\mp 2.1(exp)\mp 1.6(theor)\). A more accurate result can be achieved by: (i) better experimental data, and (ii) a higher order theoretical calculation including contributions from a couple of so far undetermined four-nucleon-two-photon operators.