Gauge and scalar boson mediated proton decay in a predictive SU(5) GUT modelDoršner, Ilja (Avtor) Džaferović-Mašić, Emina (Avtor) Fajfer, Svjetlana (Avtor) Saad, Shaikh (Avtor) physics of elementary particlesWe assess proton decay signatures in the simplest viable $SU(5)$ model with regard to constraints on parameters governing the Standard Model fermion mass spectrum. Experimental signals for all eight two-body proton decay processes result from exchange of two gauge bosons, a single scalar leptoquark, or their combination. Consequently, it enables us to delve into an in-depth anatomy of proton decay modes and anticipate future signatures. Our findings dictate that observing a proton decay into $p \to \pi^0 e^+$ indicates gauge boson mediation, with the potential for observation of $p \to \eta^0 e^+$ mode. Alternatively, if decay is through the $p \to K^+ \bar{\nu}$ process, it is mediated by a scalar leptoquark, possibly allowing the observation of $p \to \pi^0 \mu^+$. Detection of both $p \to \pi^0 e^+$ and $p \to K^+ \bar{\nu}$ could enhance $p \to \pi^0 \mu^+$ through constructive interference. The model predicts inaccessibility of $p \to \pi^+\bar{\nu}$, $p \to \eta^0 \mu^+$, $p \to K^0 e^+$, and $p \to K^0 \mu^+$, regardless of the dominant mediation type, in the coming decades. In summary, through a comprehensive analysis of proton decay signals, gauge coupling unification, and fermion masses and mixing, we both accurately and precisely constrain the parameter space of the $SU(5)$ model in question.20242024-04-25 11:33:55Članek v reviji155975UDK: 539.1ISSN pri članku: 2470-0010DOI: 10.1103/PhysRevD.109.075023COBISS_ID: 193887491sl