Theoretical studies on structural properties and decay modes of $^{284-375}$119 isotopes

In this manuscript, we analyze the structural properties of $Z=119$ superheavy nuclei in the mass range of 284 $\le$ A $\le$ 375 within the framework of axially deformed relativistic mean field theory (RMF) and calculate the binding energy, radii, quadrupole deformation parameter, separation energies and density profile. To investigate the phenomenon of shape coexistence the RMF calculations are performed within three possible solutions i.e. prolate, oblate and spherical configurations. To get a better visualization of nucleon and total matter distribution, two-dimensional contour representation of density distribution for $^{291}$119 and $^{303}$119 has been made. Further, a competition between possible decay modes such as $\alpha-$decay, $\beta-$decay and spontaneous fission (SF) of the isotopic chain of $Z=119$ superheavy nuclei under study is systematically analyzed within self-consistent relativistic mean field model. Our analysis confirmed that $\alpha-$decay is restricted within the mass range 284 $\leq$ A $\leq$ 296 and thus being the dominant decay channel in this mass range. There is no possibility of $\beta-$decay for the considered isotopic chain. In addition, we forecasted the $\alpha-$decay chain of fission survival nuclides i.e. $^{284-296}$119 and found as one $\alpha$ chain from $^{284}$119 and $^{296}$119, two consistent $\alpha$ chains from $^{285}$119 and $^{295}$119, three consistent $\alpha$ chains from $^{286}$119 and $^{294}$119, four consistent alpha chains from $^{287}$119, six consistent alpha chains from $^{288-293}$119. Thus, such studies can be of great significance to the experimentalists in very near future for synthesizing $Z=119$ superheavy nuclei.