Advancing String Theory with 4G Model of Final Unification

In the framework of the recently proposed 4G model of final unification, integrating three large atomic gravitational constants corresponding to the electromagnetic, strong, and electroweak interactions, we explore the physical existence of a fundamental electroweak fermion of rest energy 585 GeV. This particle is envisioned as the "zygote" of all elementary fermions and as the weak‐field counterpart to photons and gluons. Using three core assumptions and five defining relations, the model quantitatively reproduces key nuclear and particle physics observables, including the strong coupling constant, nuclear binding energies, neutron lifetime, charge radii, and several dimensionless large numbers. Theoretical string tensions and energies are derived for each atomic interaction (weak, strong, electromagnetic) using experimentally relevant scales (GeV–MeV–eV) rather than the inaccessible Planck scale, thus extending string theory's applicability to testable low‑energy domains. Comparative analysis (Tables 1 and 2) demonstrates close agreement between calculated string energies and known interaction energies, providing a bridge between quantum gravity concepts and measurable nuclear data. String theory’s mathematical consistency requires experimental grounding. Systematically testing different sets of the three atomic gravitational constants (Ge, Gn, Gw) over the next 15 years offers a practical pathway to advance string theory from an abstract mathematical framework to a viable predictive model with experimentally testable interaction-level phenomena. The model predicts astrophysical signatures of the 585 GeV fermion through annihilation and acceleration processes generating TeV–multi‑TeV photons, consistent with Fermi-LAT gamma-ray excesses in the Milky Way halo (0.5–0.8 TeV dark matter mass range, 20 GeV spectral peaks). Our 4G model's charged electroweak fermion at 585 GeV/c² exhibits remarkable numerical proximity to half the supersymmetric Higgsino mass (1.1–1.2) TeV/c², where 2×585 GeV = 1.170 TeV precisely matches both the central Higgsino prediction and the H.E.S.S. cosmic-ray electron spectral break energy. This triple correspondence among independent phenomena, the predicted mass doubling, Higgsino dark matter candidate, and observed electron spectrum transition, reinforces alignment with dark matter, supersymmetry, and high-energy astrophysics theories. The charged fermion may manifest through electron-positron pair production or annihilation processes contributing to the 1.17 TeV spectral characteristics. Such convergence provides compelling experimental search avenues bridging nuclear physics, particle phenomenology, and cosmic-ray astrophysics while demonstrating the model’s ability to unify fundamental constants within an experimentally testable string–gravitational framework.