# Multiple chiral doublet bands with octupole correlations in reflection-asymmetric triaxial particle rotor model

## TL;DR

This paper develops a reflection-asymmetric triaxial particle rotor model to study multiple chiral doublet bands with octupole correlations in $^{78}$Br, achieving good agreement with experimental data and revealing the impact of triaxial deformation on electromagnetic transition rates.

## Contribution

The paper introduces a novel reflection-asymmetric triaxial particle rotor model incorporating octupole correlations for analyzing chiral doublet bands.

## Key findings

- Calculated energies and transition ratios agree with experimental data.
- Triaxial deformation significantly affects $B(E1)$ transition probabilities.
- Adjusting deformation parameter $oldsymbol{ extgamma}$ improves model-data agreement.

## Abstract

A reflection-asymmetric triaxial particle rotor model (RAT-PRM) with a quasi-proton and a quasi-neutron coupled with a reflection-asymmetric triaxial rotor is developed and applied to investigate the multiple chiral doublet (M$\chi$D) bands candidates with octupole correlations in $^{78}$Br. The calculated excited energies, energy staggering parameters, and $B(M1)/B(E2)$ ratios are in a reasonable agreement with the data of the chiral doublet bands with positive- and negative-parity. The influence of the triaxial deformation $\gamma$ on the calculated $B(E1)$ is found to be significant. By changing $\gamma$ from 16$^\circ$ to 21$^\circ$, the $B(E1)$ values will be enhanced and better agreement with the $B(E1)/B(E2)$ data is achieved. The chiral geometry based on the angular momenta for the rotor, the valence proton and valence neutron is discussed in details.