Range corrections in Proton Halo Nuclei

We analyze the effects of finite-range corrections in halo effective field theory for S-wave proton halo nuclei. We calculate the charge radius to next-to-leading order and the astrophysical S-factor for low-energy proton capture to fifth order in the low-energy expansion. As an application, we confront our results with experimental data for the S-factor for proton capture on Oxygen-16 into the excited $1/2^+$ state of Fluorine-17. Our low-energy theory is characterized by a systematic low-energy expansion, which can be used to quantify an energy-dependent model error to be utilized in data fitting. Finally, we show that the existence of proton halos is suppressed by the need for two fine tunings in the underlying theory.Comment: 30pages, 12 figure

Constraining Low-Energy Proton Capture on Beryllium-7 through Charge Radius Measurements

In this paper, we point out that a measurement of the charge radius of Boron-8 provides indirect access to the S-factor for radiative proton capture on Beryllium-7 at low energies. We use leading-order halo effective field theory to explore this correlation and we give a relation between the charge radius and the S-factor. Furthermore, we present important technical aspects relevant to the renormalization of pointlike P-wave interactions in the presence of a repulsive Coulomb interaction.Comment: Accepted for publication in European Physical Journal A. 29 pages, 9 figure

Effective field theory for proton halo nuclei

We use halo effective field theory to analyze the universal features of proton halo nuclei bound due to a large S-wave scattering length. Our work provides a fully field-theoretical treatment of bound halo nuclei in the presence of a repulsive Coulomb interaction. With a Lagrangian built from effective core and valence-proton fields, we derive a leading-order expression for the charge form factor. Within the same framework we also calculate the radiative proton capture cross section. We present general results at leading order that can be applied to any one-proton halo system bound in a relative S wave. We illustrate the method by studying the excited 1/2(+) state of fluorine 17, for which we give results for the charge radius and the astrophysical S factor

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

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 / Ac, where Ac 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 / Ac. 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

Effective field theory for proton halo nuclei

We use halo effective field theory to analyze the universal features of proton halo nuclei bound due to a large S-wave scattering length. Our work provides a fully field-theoretical treatment of bound halo nuclei in the presence of a repulsive Coulomb interaction. With a Lagrangian built from effective core and valence-proton fields, we derive a leading-order expression for the charge form factor. Within the same framework we also calculate the radiative proton capture cross section. We present general results at leading order that can be applied to any one-proton halo system bound in a relative S wave. We illustrate the method by studying the excited 1/2 + state of fluorine 17, for which we give results for the charge radius and the astrophysical S factor

Three-Body Halo States in Effective Field Theory: Renormalization and Three-Body Interactions in the Helium-6 System

In this paper we study the renormalization of Halo effective field theory applied to the Helium-6 halo nucleus seen as an alpha-neutron-neutron three-body state. We include the 0(+) dineutron channel together with both the 3/2(-) and 1/2(-) neutron-alpha channels into the field theory and study all of the six lowest-order three-body interactions that are present. Furthermore, we discuss three different prescriptions to handle the unphysical poles in the P-wave two-body sector. In the simpler field theory without the 1/2(-) channel present we find that the bound-state spectrum of the field theory is renormalized by the inclusion of a single three-body interaction. However, in the field theory with both the 3/2(-) and 1/2(-) included, the system can not be renormalized by only one three-body operator

The Doughnut for Urban Development:Manual, Appendix and Database

With the Doughnut for Urban Development we are using doughnut economics as a model for urban development and construction for the first time. Doughnut Economics has previously been used with great success globally and for urban strategies ranging from Amsterdam to Copenhagen.We have developed the Manual to provide the entire industry with a practical tool to evaluate the sustainability of their projects and what they can do to make them even more sustainable. The manual embraces both social and planetary sustainability and incorporates both local and global dimensions.The Doughnut for Urban Development is an open-source project and all the following resources can be downloaded for free:- The Manual- A scientific Appendix providing background for the Manual- A Database of impact areas used in the manual- A tool to assess a project's biodiversity impacts throughout its life cycl

Cluster Effective Field Theory

Halo nuclei are loosely bound systems consisting of a core plus valence nucleon(s). In so called Halo, or Cluster, effective field theory, the core of the halo nucleus is treated as an effective degree-of-freedom without internal structure. As such, Cluster effective field theory is a low-energy model, appropriate for the typical momentum scales of halo physics. The advantages of using effective field theory are the systematic way of improving results, by including higher orders in the momentum expansion, and the rigorous error estimates that are available at each order.In this thesis we present a formalism for treating one-proton and two-neutron halo nuclei in effective field theory, with an emphasis on charge radii, astrophysical S-factors, and the renormalization of three-body states. We also discuss a new power-counting scheme for heavy-core systems and introduce finite-size contributions. For one-proton halo nuclei we derive formalism for S- and P-wave systems, which we exemplify by studying the one-proton halo states 17F* and 8B, respectively. Of particular significance are: (i) our calculation of the radiative capture cross section of 16O(p,gamma)17F* to fifth order in the S-wave system and (ii) our derivation of a leading-order correlation between the charge radius of 8B and the threshold S-factor of 7Be(p,gamma)8B for the P-wave system.Our alternative power counting for halo nuclei with a heavy core leads to a new organizational principle that demotes the naive leading-order contributions to the charge radius for neutron halos. Additionally, in this new power counting we include the finite-size effects of the constituents explicitly into the field theory and derive how their finite sizes contribute to the charge radius of S- and P-wave one-neutron and one-proton halo states.For two-neutron halo systems we derive the field-theory integral equations to study both bound and resonant states. We apply the formalism to the 0+ channel of 6He. In this three-body field theory we include both the 3/2- and the 1/2- channels of the alpha-n subsystem, together with the 0+ channel of the n-n part. Furthermore, we include the relevant three-body interactions and analyze, in particular, the renormalization of the system

Effective Field Theory and One-proton Halo Nuclei

In this thesis we present formalism for treating one-proton halo nuclei in effective field theory. Halo nuclei are loosely bound systems consisting of a core plus valence nucleon(s). In so called Halo, or Cluster, effective field theory, the core of the halo nucleus is treated as a structureless, effective degree-of-freedom. As such, Cluster effective field theory is a low-energy model, appropriate for typical momentum scales of halo physics. The advantages of using effective field theory are the systematic way of improving results, by including higher orders, and the rigorous error estimates at each order. The observables that we consider are the charge form factor and the radiative capture cross section. A leading-order correlation between these observables is also derived. The framework is presented to next-to-leading order for S-wave interactions and to leading order for P-wave interactions. The formalism is exemplified by applying it to study the one-proton halo states 17F* and 8B. Results are presented for the charge radii of these systems and the S-factors of the radiative capture reactions 16O(p,γ)17F* and 7Be(p,γ)8B. The S-factor results compare well with data and previous calculations