Neutrino mass spectroscopy using Er³⁺ ions placed at inversion center of host crystals

We propose neutrino mass spectroscopy using Er$^{3+}$:Cs$_2$NaYF$_6$ or :Y$_2$O$_3$ crystal placed in hollow of a Bragg fiber as a target system. Unknown neutrino parameters and properties such as the lightest neutrino mass, Majorana/Dirac distinction, and CP violating phases can be explored by measuring scattered photons ($\gamma$) along the excitation (and fiber) axis by varying Raman trigger ($\gamma_0$) directions, in Er$^{3+}$ de-excitation process from $|e\rangle $ state to $|g\rangle $ state; $|e\rangle \,, | e\rangle + \gamma_0 \rightarrow | g\rangle + \gamma + \nu_i\bar{\nu}_j$, $\nu_i\,, i = 1, 2,3$ being a mass-resolved neutrino state. Rates and required level of QED background rejection are calculated using measured data of the target system.