Role of symmetries in nuclear physics
- PDF / 203,102 Bytes
- 4 Pages / 481.89 x 708.661 pts Page_size
- 116 Downloads / 192 Views
part of Springer Nature, 2020 https://doi.org/10.1140/epjst/e2020-000209-2
THE EUROPEAN PHYSICAL JOURNAL SPECIAL TOPICS
Editorial
Role of symmetries in nuclear physics Venkata Krishna Brahmam Kota1,a and Ashok Kumar Jain2 1 2
Physical Research Laboratory, Ahmedabad 380 009, India Amity Institute of Nuclear Science & Technology, Amity University, Noida 201301, UP, India Received 2 September 2020 / Accepted 2 September 2020 Published online 23 October 2020 Abstract. We briefly describe the motivation for the special issue on ’Role of symmetries in Nuclear Physics’. In addition, we also present an overview of the topics covered in this special issue.
Symmetries pervade every area of physics and are universally accepted to play a unifying role, more so in the microscopic domain. However, nearly all the symmetries, including those having geometric connotations, are invisible. This invisibility imparts them a mysterious nature, manifesting in many mathematical groups. We confirm their presence by various observables in experimental data, like specific patterns in the energy spectra, special relationships between transition rates, and emergence of various selection rules. Heisenberg’s introduction of isospin with SU (2) [1,2], Wigner’s spin–isospin SU (4) [3], Elliott’s SU (3) for rotational nuclei [4–7] and Racah’s pairing quasi-spin SU (2) [2,8] algebras are benchmark examples of symmetry principles in nuclei. These various Lie algebraic symmetries and their many extensions within the nuclear shell model [2,9] have been investigated during the nineteen sixties and they played a major role in providing an organized description of nuclear data and a deeper understanding of nuclear structure [10–13]. A renaissance in applying symmetries to organize and explain large amount of nuclear data was witnessed by the introduction of the interacting boson model [14] in the late seventies with U (6) spectrum generating algebra containing vibrational U (5), rotational SU (3), and γ-unstable O(6) symmetries. Various extensions of the interacting boson model also came into being, which include interacting boson-fermion models for odd mass and odd-odd nuclei developed during eighties and nineties and applications to quantum phase transitions and clustering in nuclei in the last 20 years [15–18]. In addition, a new line of research using point group symmetries for cluster configurations in lighter N ∼ Z nuclei has opened up [19,20]. All these and extensions of the shell model description to include multi-shell excitations using SU (3) basis and also via the so called Sp(6, R) ⊃ SU (3) symmetry [21–23], giving no-core shell model, established symmetry principles to be an important part of nuclear physics. Besides these, opening a new direction, there is growing evidence for the importance of isospin and also spin–isospin SU (4) in heavy nuclei [24–26]. On the other hand, there are several new studies involving fundamental symmetries such as rotational invariance, time-reversal, parity and so on in statistical nuclear physics with parti
Data Loading...
