Speaker
Dr
Yi Hua Lam
(CEN Bordeaux-Gradignan)
Description
The influence of isospin nonconservation is important for testing the fundamental symmetries underlying the Standard Model, e.g., corrections to superallowed 0+ -> 0+ -decay rates [Towner and Hardy (2010)], and is pivotal for computing theoretical amplitudes for nucleon transfer reaction which violates isospin selection rule [Blank and Borge (2008)]. Recently, we have constructed a realistic isospin-nonconserving (INC) shell-model Hamiltonian in sd shell. The INC Hamiltonian consists of an isospin-conserving Hamiltonian, i.e. either USD [Brown and Wildenthal (1988)], or USDA, or USDB interactions [Richter and Brown (2008)], a Coulomb interaction, and a phenomenological charge-dependent forces of nuclear origin. All charge-dependent strengths were determined by a least-squares fit to reproduce newly compiled experimental coefficients of the isobaric multiplet mass equation (IMME) [Y.H.L. et al. (2013)] with very low root-mean-square deviation values 33 keV [Y.H.L. et al. (2013)]. This INC Hamiltonian provides an accurate theoretical description of the isospin mixing in nuclear states.
We present two of the important applications: (a) the microscopic description of staggering behavior of IMME isovector and isotensor coefficients; and (b) the breaking of the quadratic IMME in A = 24 , 28 , 32 quintets. Overall, this new INC Hamiltonian shows its robustness in providing an accurate theoretical description of the isospin mixing in nuclear states of sd shell nuclei.
Primary author
Dr
Yi Hua Lam
(CEN Bordeaux-Gradignan)
Co-authors
Dr
Etienne Caurier
(IPHC Strasbourg)
Dr
Nadya A. Smirnova
(TU Darmstadt)
