• The evolution of the chiral symmetry in cesium isotopes

    分类: 物理学 >> 核物理学 提交时间: 2023-07-03

    摘要: Following the reports of candidate chiral doublet bands observed in cesium isotopes, the possible chiral candidates and the evolution of three-dimensional rotation in $^{120-134}{ textrm{Cs}}$ are investigated within the microscopic three-dimensional tilted axis cranking covariant density functional theory (3DTAC-CDFT). By investigating the evolution of the polar angle $ theta$ and azimuth angle $ varphi$ as a function of rotational frequency $ hbar omega$, the transition from the planar rotation to the chiral rotation has been found in $^{121-133}{ textrm{Cs}}$. The corresponding critical rotational frequency $ omega_{ textrm{crit}}$ of the appearance of chiral aplanar rotation decreases as neutron number increases, which can be attributed to the neutrons in $(gd)$ and $(sd)$ shells having smaller angular momentum components along both the short and long axes, and larger components along medium axis, respectively. In comparison, only planar rotation has been obtained in $^{120,134}{ textrm{Cs}}$. With these interpretations, the obtained $I sim hbar omega$ and energy spectra as well as $B(M1)/B(E2)$ values show reasonable agreement with the available experimental data. In addition, the evolution of quadrupole deformation $ beta$ and triaxial deformation $ gamma$ are also discussed.

  • Interference effects on Higgs mass measurement in $e^+e^-\to H(\gamma\gamma) Z$ at CEPC

    分类: 物理学 >> 核物理学 提交时间: 2016-09-13

    摘要: A high luminosity Circular Electron Positron Collider (CEPC) as a Higgs Factory will be helpful to the precision measurement of the Higgs mass. The signal-background interference effect is carefully studied for the Higgs diphoton decay mode in the associated Z boson production at the future e+e− colliders at energy 246GeV. The mass shifts go up from about 20MeV to 50MeV for the experimental mass resolution ranging from 0.8GeV to 2GeV.