Nuclear modification factor in intermediate-energy heavy-ion collisions

The transverse momentum dependent nuclear modification factors (NMF), namely $R_{CP}$, is investigated for protons produced in Au + Au at 1$A$ GeV within the framework of the isospin-dependent quantum molecular dynamics (IQMD) model. It is found that the radial collective motion during the expansion stage affects the NMF at low transverse momentum a lot. By fitting the transverse mass spectra of protons with the distribution function from the Blast-Wave model, the magnitude of radial flow can be extracted. After removing the contribution from radial flow, the $R_{CP}$ can be regarded as a thermal one and is found to keep unitary at transverse momentum lower than 0.6 GeV/c and enhance at higher transverse momentum, which can be attributed to Cronin effect.Comment: 8 pages, 5 figures; aceepted by Physics Letters

Chiral geometry of higher excited bands in triaxial nuclei with particle-hole configuration

The lowest six rotational bands have been studied in the particle-rotor model with the particle-hole configuration $\pi h^1_{11/2}\otimes\nu h^{-1}_{11/2}$ and different triaxiality parameter $\gamma$. Both constant and spin-dependent variable moments of inertial (CMI and VMI) are introduced. The energy spectra, electromagnetic transition probabilities, angular momentum components and $K$-distribution have been examined. It is shown that, besides the band 1 and band 2, the predicted band 3 and band 4 in the calculations of both CMI and VMI for atomic nuclei with $\gamma=30^\circ$ could be interpreted as chiral doublet bands.Comment: 4 pages, 4 figure