The decay properties of Hassium isotopes are examined through a detailed analysis of their half-lives for various decay modes, including \(\alpha\) -decay, \(\beta ^{-}\) -decay, \(\beta ^{+}\) -decay, and spontaneous fission. \(\alpha\) -decay half-lives are calculated using the Unified Fission Model with a Woods–Saxon potential, while analytical formulas are employed for \(\beta\) -decay and spontaneous fission. A preliminary comparison of four mass models (LDM, DZ28, WS4, FRDM), enhanced via machine learning techniques, identifies the improved WS4 model as the most accurate for predicting \(\alpha\) -decay Q-values. Using this model, the competition between decay modes in Hassium isotopes is systematically investigated. Results reveal that \(\beta ^{+}\) and \(\beta ^{-}\) decays are far less competitive compared to \(\alpha\) -decay and spontaneous fission, both of which exhibit significantly shorter half-lives. Neutron-deficient and neutron-rich isotopes are found to predominantly undergo spontaneous fission, whereas intermediate isotopes ( \(^{259}\) Hs and \(^{261-275}\) Hs) primarily decay via \(\alpha\) -emission. Notably, the possibility of \(\beta ^{+}\) -decay is identified around \(^{269}\) Hs. A total of 16 decay chains have been constructed, along with their associated decay modes and half-lives. The predicted decay modes exhibit strong agreement with available experimental observations, thereby reinforcing confidence in the reliability of the calculated decay chains that have not yet been experimentally confirmed.
