This page is a convenience sample of physics papers suggesting causes for the values of the Standard Model of Particle Physics' experimentally measured constants, which I update from time to time. They are listed in order of publication from most recent to oldest. I do not render any opinion on the merits of these proposals.
Nobuhito Maru, Yoshiki Yatagai, "Fermion Mass Hierarchy in Grand Gauge-Higgs Unification"
Van E. Mayes "All Fermion Masses and Mixings in an Intersecting D-brane World"
Alexander Baur, Hans Peter Nilles, Andreas Trautner, Patrick K.S. Vaudrevange, "Unification of Flavor, CP, and Modular Symmetries"
Andrea Wulzer, "Behind the Standard Model"
Junu Jeong, Jihn E. Kim, Se-Jin Kim, "Flavor mixing inspired by flipped SU(5) GUT"
Gauhar Abbas, "A new solution of the fermionic mass hierarchy of the standard model"
Emiliano Molinaro, Francesco Sannino, Zhi-Wei Wang, "Safe Pati-Salam"
J. T. Penedo, S. T. Petcov, "Lepton Masses and Mixing from Modular S4 Symmetry"
Yoshio Koide, Hiroyuki Nishiura, "Parameter-Independent Quark Mass Relation in the U(3)×U(3)′ Model"
T. K. Kuo, S. H. Chiu, "Flavor Mixing and the Permutation Symmetry among Generations"
M. Novello, V. Antunes, "Connecting the Cabbibo-Kobayashi-Maskawa matrix to quark masses"
Astrid Eichhorn, Aaron Held, "Mass difference for charged quarks from asymptotically safe quantum gravity"
Kevin Loch, "Emperically [sic] Derived Fermion Higgs Yukawa Couplings and Pole Masses"
http://vixra.org/abs/1711.0388 (note that links to vixra are to papers by non-professional physicists, some of which are contrary to accepted scientific findings and theories)
HM Chan, ST Tsou, "The Framed Standard Model (I) - A Physics Case for Framing the Yang-Mills Theory?"
Stephen F. King "A model of quark and lepton mixing"
J. Lemmon, "The origin of fermion families and the value of the fine structure constant"