Finite-size effects in heavy halo nuclei from effective field theory

Journal Article · Wed Jan 01 00:00:00 EST 2020 · European Physical Journal. A

DOI:https://doi.org/10.1140/epja/s10050-019-00001-1· OSTI ID:1800178

Ryberg, E.; Forssén, C.; Phillips, D. R.; van Kolck, U.

Abstract Halo/Cluster Effective Field Theory describes halo/cluster nuclei in an expansion in the small ratio of the size of the core(s) to the size of the system. Even in the point-particle limit, neutron-halo nuclei have a finite charge radius, because their center of mass does not coincide with their center of charge. This point-particle contribution decreases as$$$$1/A_\mathrm {c}$$$$ $1/A_c$, where$$$$A_\mathrm {c}$$$$ $A_c$is the mass number of the core, and diminishes in importance compared to other effects, e.g., the size of the core to which the neutrons are bound. Here we propose that for heavy cores the EFT expansion should account for the small factors of$$$$1/A_\mathrm {c}$$$$ $1/A_c$. As a specific example, we discuss the implications of this organizational scheme for the inclusion of finite-size effects in expressions for the charge radii of halo nuclei. We show in particular that a short-range operator could be the dominant effect in the charge radius of one-neutron halos bound by a P-wave interaction. The point-particle contribution remains the leading piece of the charge radius for one-proton halos, and so Halo EFT has more predictive power in that case.

• Research Organization: Univ. of Arizona, Tucson, AZ (United States); Ohio Univ., Athens, OH (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: FG02-04ER41338; FG02-93ER40756
• OSTI ID: 1800178
• Journal Information: European Physical Journal. A, Vol. 56, Issue 1; ISSN 1434-6001
• Publisher: Springer
• Country of Publication: United States
• Language: English

Related Subjects

Physics