Optical potentials for the rare-isotope beam era

We review recent progress and motivate the need for further developments in nuclear optical potentials that are widely used in the theoretical analysis of nucleon elastic scattering and reaction cross sections. In regions of the nuclear chart away from stability, which represent a frontier in nuclear science over the coming decade and which will be probed at new rare-isotope beam facilities worldwide, there is a targeted need to quantify and reduce theoretical reaction model uncertainties, especially with respect to nuclear optical potentials. We first describe the primary physics motivations for an improved description of nuclear reactions involving short-lived isotopes, focusing on its benefits for fundamental science discoveries and applications to medicine, energy, and security. We then outline the various methods in use today to build optical potentials starting from phenomenological, microscopic, and ab initio methods, highlighting in particular the strengths and weaknesses of each approach. We then discuss publicly-available tools and resources facilitating the propagation of recent progresses in the field to practitioners. Finally, we provide a set of open challenges and recommendations for the field to advance the fundamental science goals of nuclear reaction studies in the rare-isotope beam era.Comment: This paper is the outcome of the Facility for Rare Isotope Beams Theory Alliance (FRIB - TA) topical program "Optical Potentials in Nuclear Physics" held in March 2022 at FRIB. Its content is non-exhaustive, was chosen by the participants and reflects their efforts related to optical potential

Analysis of corrections to the eikonal approximation

Various corrections to the eikonal approximations are studied for two- and three-body nuclear collisions with the goal to extend the range of validity of this approximation to beam energies of 10 MeV/nucleon. Wallace's correction does not improve much the elastic-scattering cross sections obtained at the usual eikonal approximation. On the contrary, a semiclassical approximation that substitutes the impact parameter by a complex distance of closest approach computed with the projectile-target optical potential efficiently corrects the eikonal approximation. This opens the possibility to analyze data measured down to 10 MeV/nucleon within eikonal-like reaction models.Comment: 10 pages, 8 figure

Ab initio investigations of A=8A=8 nuclei: α−α\alpha{-}\alpha scattering, deformation in 8^8He, radiative capture of protons on 7^7Be and 7^7Li and the X17 boson

International audienceWe apply the No-Core Shell Model with Continuum (NCSMC) that is capable of describing both bound and unbound states in light nuclei in a unified way with chiral two- and three-nucleon interactions as the only input. The NCSMC can predict structure and dynamics of light nuclei and, by comparing to available experimental data, test the quality of chiral nuclear forces. We discuss applications of NCSMC to the $\alpha{-}\alpha$ scattering and the structure of $^8$Be, the p+$^7$Be and p+$^7$Li radiative capture and the production of the hypothetical X17 boson claimed in ATOMKI experiments. The $^7$Be(p,$\gamma$)$^8$B reaction plays a role in Solar nucleosynthesis and Solar neutrino physics and has been subject of numerous experimental investigations. We also highlight our investigation of the neutron rich exotic $^8$He that has been recently studied experimentally at TRIUMF with an unexpected deformation reported

HTA - How to tackle pressing challenges: International Harmonization, Real World Data, and Surrogates

Health Technology Assessment is one of the standard instruments in support of the decision-making to define the public health services both internationally and in the German health care system. Besides systematic reviews, benefit-harm-analyses, health economic evaluations, and, decision-analytic modelling, especially epidemiological and biometrical questions and methods play a key role. From this perspective discussions on increased European cooperation including calls for wider harmonization are attracting greater interests.The overall aim is, to present at the GMDS workshop relevant information on this emerging field of harmonization in Europe across similarities and differences in the HTA process. Current developments around the composition of the EU-HTA Network are provided. This network accepts the challenge to define and establish a "Joint Work" across Europe. Special emphasis was placed on the discussion on "Harmonization of HTA: is it a threat or does it mean support?". Furthermore, methodological discussions and questions are being addressed: "Are Real World Data and Surrogates possible parameters for decision-making or HTA?"Health Technology Assessment (Gesundheitstechnologiefolgenabschätzung) gehört international und im deutschen Gesundheitswesen zu den Standardinstrumenten der Entscheidungsunterstützung zur Definition des Leistungskatalogs. Neben systematischen Reviews, Nutzen-Schaden-Abwägungen, gesundheitsökonomischen Evaluationen und entscheidungsanalytischen Modellierungen spielen insbesondere epidemiologische und biometrische Fragen und Methoden eine Rolle. Vor diesem Hintergrund geraten die zunehmenden Diskussionen um europäische Zusammenarbeit in den Fokus bis hin zu Rufen nach umfangreicher Harmonisierung. Die GMDS-Arbeitsgruppe HTA möchte gemeinsam mit den AG/AK Methodik Systematischer Reviews, Gesundheitsökonomie und Medical Decision Making dieses Thema aufgreifen und aktuelle Entwicklungen darstellen. Dies beginnt mit einem europäischen Blick auf den Aufbau des EU-HTA-Netzwerks, das sich der Herausforderung stellt, "Joint Work" europaweit zu definieren und zu etablieren. Hier rückt die Diskussion um "Harmonisierung von HTA" in den Vordergrund: Ist dies als Bedrohung oder als Unterstützung zu werten? Im zweiten Teil des Artikels wird vor diesem Hintergrund eine weitere aktuelle methodische Frage aus verschiedenen Perspektiven erörtert: "Sind Real World Data und Surrogate mögliche Parameter im Decision Making oder in der Gesundheitstechnologiefolgenabschätzung?"

Shaping a research agenda to ensure a successful European health technology assessment: insights generated during the inaugural convention of the European access academy

Julian E, Pavlovic M, Sola-Morales O, et al. Shaping a research agenda to ensure a successful European health technology assessment: insights generated during the inaugural convention of the European access academy. Health Economics Review . 2022;12(1): 54.OBJECTIVES: Key challenges for a joint European Health Technology Assessment (HTA) include consolidated approaches towards the choice of adequate comparator(s), selection of endpoints that are relevant to patients with a given disease, dealing with remaining uncertainties as well as transparent and consistent management of related processes. We aimed to further crystallize related core domains within these four areas that warrant further research and scrutiny.; METHODS: Building on the outcomes of a previously conducted questionnaire survey, four key areas, processes, uncertainty, comparator choice and endpoint selection, were identified. At the inaugural convention of the European Access Academy dedicated working groups were established defining and prioritizing core domains for each of the four areas. The working groups consisted of~10 participants each, representing all relevant stakeholder groups (patients/ clinicians/ regulators/ HTA & payers/ academia/ industry). Story books identifying the work assignments were shared in advance. Two leads and one note taker per working group facilitated the process. All rankings were conducted on an ordinal Likert Response Scale scoring from 1 (low priority) to 7 (high priority).; RESULTS: Identified key domains include for processes: i) address (resource-) challenge of multiple PICOs (Patient/ Intervention/ Comparator/ Outcomes), ii) time and capacity challenges, iii) integrating all involved stakeholders, iv) conflicts and aligning between different multi-national stakeholders, v) interaction with health technology developer; for uncertainty: i) early and inclusive collaboration, ii) agreement on feasibility of RCT and acceptance of uncertainty, iii) alignment on closing evidence gaps, iv) capacity gaps; for comparator choice: i) criteria for the choice of comparator in an increasingly fragmented treatment landscape, ii) reasonable number of comparators in PICOs, iii) shape Early Advice so that comparator fulfils both regulatory and HTA needs, iv) acceptability of Indirect Treatment Comparisons (ITC), v) ensure broad stakeholder involvement in comparator selection; for endpoint selection: i) approaching new endpoints; ii) patient preferences on endpoints; iii) position of HTA and other stakeholders; iv) long-term generation and secondary use of data; v) endpoint challenges in RCTs.; CONCLUSIONS: The implementation of a joint European HTA assessment is a unique opportunity for a stronger European Health Union. We identified 19 domains related to the four key areas, processes, uncertainty, comparator choice and endpoint selection that urgently need to be addressed for this regulation to become a success. © 2022. The Author(s)