NIHAM
NIHAM
Centre of Excellence
NUCLEAR INTERACTIONS AND HADRONIC MATTER
Project Title: From Nuclei to Stars: Towards a Comprehensive Understanding
Financing agency: UEFISCDI
Project Type/Code: Exploratory Research Project / PN-III-P4-PCE-2021-0060
Contract Number PCE 8/2022
Project Summary: Summary: The new experimental facilities open the frontiers in low-energy nuclear science allowing to address the underlying physics of nuclei leading to understanding the origin of elements in universe. Essential open questions will be raised within the project: how does the effective nuclear force depend on proton-to-neutron ratio; which are the relevant degrees of freedom and symmetries of nuclear systems at extremes of isospin; how does shape coexistence/mixing influence the weak decays of exotic nuclei expected to significantly affect the astrophysical scenarios concerning rp-process and r-process path and the forbidden transitions of nuclei dominating the reactor antineutrino anomaly. The efforts will be focused on structure and dynamics of medium mass proton-rich nuclei around N=Z line up to 100Sn and neutron-rich nuclei in A~100 region. Our goal is to obtain robust predictions on structure and weak interaction rates based on a realistic description of the available experimental data. Special effort will be devoted to refine the realistic effective interactions obtained from a G-matrix based on the Bonn CD potential in large model spaces to properly account for the essential degrees of freedom in exotic medium mass nuclei. Shape coexistence phenomena will be self-consistently treated in the framework of the beyond-mean-field complex Excited Vampir model aiming to a comprehensive description of the results of experiments on properties to limits of existence.

Domain of the project:
Domain: PE. MATHEMATICS, PHYSICAL SCIENCES, INFORMATION AN COMMUNICATION, ENGINEERING, UNIVERSE AND EARTH SCIENCES
Subdomain: PE2. Fundamental constituents of matter: partricle, nuclear, plasma, atomic, molecular, gas and optical physics
Main Research Area: PE2_3. Nuclear Physics
Secondary Research Area: PE2_1. Fundamental interactions and fields
Secondary Research Area: PE2_4. Nuclear astrophysics


Keywords:
exotic medium-mass nuclei; coexistence phenomena; terrestrial and stellar weak interaction rates; realistic effective interactions; beyond-mean-field approaches.

Project leader: Alexandrina Petrovici
E-mail address: [email protected]

Host institution of the project:
Institution name: Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering
Institution address:  30 Reactorului St., Magurele, jud. Ilfov, P.O.B. MG-6, RO-077125, Romania
Project results: In this project we addressed essential open questions concerning the structure and dynamics of exotic medium mass nuclei relevant for the understanding of fundamental symmetries and interactions and having impact on nucleosynthesis processes. Shape coexistence and mixing becoming progressively the fundamental defining characteristics of nuclei near the N=Z line and the A ~ 100 neutron-rich nuclei required the development and application of the complex Excited Vampir beyond-mean-field model enabling the use of realistic effective interactions in large model spaces. We achieved the first unitary description of isomeric states and beta decay properties for the investigated proton-rich nuclei. We obtained a comprehensive understanding of the multifaceted impact of shape coexistence on the first-forbidden beta decay and the structure and dynamics of the populated states in exotic neutron-rich nuclei.  
List of publications:

1.Shape coexistence and isomeric states in 94Pd within a beyond-mean-field approach,
A. S. Mare, A. Petrovici
Phys. Rev. C 106, 054306 (2022)

2.E0 transition strengths in 70Se and 70Kr mirror nuclei within a beyond-mean-field model,
Alexandrina Petrovici
Symmetry 14, 2594 (2022)

3.Shape coexistence and first-forbidden decay of 92Rb to 92Sr,
A. Petrovici
Phys. Rev. C 109, 024303 (2024)

4.Multifaceted impact of shape coexistence in proton-rich nuclei within a beyond-mean-field model,
A. Petrovici, O. Andrei 
accepted for publication in EPJ Web of Conferences (2024)

5.Multiple shape coexistence in 98Zr and first-forbidden beta decay of 98Y,
A. Petrovici, O. Andrei 
submitted for publication in Phys. Rev. C (2024)

6.Various facets of shape coexistence in neutron-rich nuclei within a beyond-mean-field approach,
A. Petrovici, O. Andrei 
submitted for publication in EPJ Web of Conferences (2024)


List of talks:

1.Triple shape coexistence and beta decay of 96Y to 96Zr,
A. Petrovici,
invited talk at SSNET 2022, Orsay, France, 30 May - 3 June 2022.

2.Impact of shape coexistence on the dynamics of proton-rich and neutron-rich medium mass nuclei,
A. Petrovici,
invited talk at the Charpathian Summer School of Physics 2023 (CSSP23), Sinaia, Romania, 02-15 July 2023.

3.Shape coexistence and mixing behind the isomers of 94Pd,
A. Petrovici,
talk at the 17th International Symposium on Capture Gamma-Ray Spectroscopy and Related Topics (CGS17), Grenoble, France, 17-21 July 2023.

4.Coexistence phenomena in proton-rich medium mass nuclei within a beyond-mean-field approach,
A. Petrovici,
invited talk at NUSTAR Week 2023, Bucharest-Magurele, Romania, 10-13 October 2023.

5.Various facets of shape coexistence in neutron-rich nuclei within a beyond-mean-field approach,
A. Petrovici,
talk at V International Conference on Nuclear Structure and Dynamics (NSD2024), Valencia, Spain, 27-31 May 2024.

6.Multifaceted impact of shape coexistence in proton-rich and neutron-rich nuclei within a beyond-mean-field model,
A. Petrovici,
talk at EURORIB 2024, Center Parcs De Vossemeren, Lommel, Belgium, 2-7 June 2024.

7.Magnetic moments of micro-second isomeric states at N=59 shape transition region,
J.-M. Daugas, A. Petrovici, et al. ,
talk at International Symposium on Nuclear Science (ISNS24), Sofia, Bulgaria, 9-13 September 2024

8.Beyond-mean-field approach to shape coexistence phenomena in neutron-rich nuclei,
A. Petrovici,
Invited talk at International Conferences on Shapes and Symmetries in Nuclei: from Experiment to Theory (SSNET’24), Orsay, France, 4-8 November 2024


PhD Theses:

1.Nuclear Structure and Dynamics of Exotic Medium-Mass Nuclei,
A. S. Mare
, University of Bucharest, Doctoral School in Physics, 21.10.2022 (grade Excellent)
Coordinator: Prof. Dr. Alexandrina Petrovici

2.Indirect Measurements for Nuclear Astrophysics: Proton Breakup Reaction at Intermediate Energies,
A. I. Chilug (Stefanescu)
, University of Bucharest, Doctoral School in Physics, 20.01.2023 (grade Excellent)
Coordinator: Prof. Dr. Alexandrina Petrovici