FCNC Processes from D-brane Instantons

Abstract

Low string scale models might be tested at the LHC directly by their Regge resonances. For such models it is important to investigate the constraints of Standard Model precision measurements on the string scale. It is shown that highly suppressed FCNC processes like K0- bar K^0 oscillations or leptonic decays of the D0-meson provide non-negligible lower bounds on both the perturbatively and surprisingly also non-perturbatively induced string theory couplings. We present both the D-brane instanton formalism to compute such amplitudes and discuss various possible scenarios and their constraints on the string scale for (softly broken) supersymmetric intersecting D-brane models.

28 pages, 13 figures, reference added, 1 typo corrected, style file added

References in corpus (15)

• Four-dimensional String Compactifications with D-Branes, Orientifolds and Fluxes
• Spacetime Instanton Corrections in 4D String Vacua - The Seesaw Mechanism for D-Brane Models
• Neutrino Majorana Masses from String Theory Instanton Effects
• Stringy Instantons and Quiver Gauge Theories
• Instanton Induced Neutrino Majorana Masses in CFT Orientifolds with MSSM-like spectra
• Non-perturbative Yukawa Couplings from String Instantons
• Stringy Instantons at Orbifold Singularities
• D-brane Instantons on the T^6/Z_3 orientifold
• The LHC String Hunter's Companion
• Instantons and Holomorphic Couplings in Intersecting D-brane Models
• Lifting D-Instanton Zero Modes by Recombination and Background Fluxes
• Non-perturbative superpotentials across lines of marginal stability
• The Weinberg Operator and a Lower String Scale in Orientifold Compactifications
• On mass hierarchies in orientifold vacua
• The Neutrino Suppression Scale from Large Volumes