Gauge coupling and fermion mass relations in low string scale brane models

Abstract

We analyze the gauge coupling evolution in brane inspired models with $U(3)\times U(2)\times U(1{)}^N$ symmetry at the string scale. We restrict to the case of brane configurations with two and three abelian factors (N=2,3) and where only one Higgs doublet is coupled to down quarks and leptons and only one to the up quarks. We find that the correct hypercharge assignment of the Standard Model particles is reproduced for six viable models distinguished by different brane configurations. We investigate the third generation fermion mass relations and find that the correct low energy $m_b/m_{\tau }$ ratio can be obtained for $b-\tau$ Yukawa coupling equality at a string scale as low as $M_S\sim 10^3$ TeV.

15 pages, 3 figures

References in corpus (17)

• Big Bang Nucleosynthesis (in "The Review of Particle Properties" 2004)
• The Hierarchy Problem and New Dimensions at a Millimeter
• New Dimensions at a Millimeter to a Fermi and Superstrings at a TeV
• Strong Coupling Expansion Of Calabi-Yau Compactification
• Branes Intersecting at Angles
• Weak Scale Superstrings
• Open Strings
• Three-Family Supersymmetric Standard-like Models from Intersecting Brane Worlds
• Intersecting Brane Worlds
• A D-brane alternative to unification
• Anomalous U(1)s in Type I superstring vacua
• D-branes and the Standard Model
• Gauge Unification in Supersymmetric Intersecting Brane Worlds
• Splitting Supersymmetry in String Theory
• D-Branes, Moduli and Supersymmetry
• GUT Model Hierarchies from Intersecting Branes
• A Pati-Salam model from branes

Cited by in corpus (6)

• Towards a realistic Standard Model from D-brane configurations
• Low Scale String Theory Benchmarks for Hidden Photon Dark Matter Interpretations of the XENON1T Anomaly
• D-brane Standard Model variants and Split Supersymmetry: Unification and fermion mass predictions
• Inverted neutrino mass hierarchies from U(1) symmetries
• D-brane Standard Model-Like and Scalar Dark Matter in Type IIA Superstring Theory
• Unification and fermion mass relations in low string scale D-brane models