Related papers: Yukawa Corrections from Four-Point Functions in In…
We discuss the structure of Yukawa couplings in D-brane models in which the SM fermion spectrum appears at the intersections of D-branes wrapping a compact space. In simple toroidal realistic examples one can explicitly compute the Yukawa…
To address fermion mass hierarchy and flavor mixings in the quark and lepton sectors, a minimal flavor structure without any redundant parameters beyond phenomenological observables is proposed via decomposition of the Standard Model Yukawa…
A fourth generation of Standard Model (SM) fermions is usually considered unlikely due to constraints from direct searches, electroweak precision measurements, and perturbative unitarity. We show that fermion mass textures consistent with…
We consider the Yukawa couplings for quarks and leptons in the context of Pati-Salam model using intersecting D-brane models where the Yukawa coupling matrices are rank one in a simple choice of family replication. The CKM mixings can be…
We study the structure of Yukawa couplings in intersecting D6-branes wrapping a factorizable 6-torus compact space T^6. Models with MSSM-like spectrum are analyzed and found to fail in predicting the quark mass spectrum because of the way…
In the minimal supersymmetric extension of the Standard Model (MSSM), fermion masses and Yukawa couplings receive radiative corrections at one loop from diagrams involving the supersymmetric particles. The corrections to the relation…
We calculate tree level three and four point scattering amplitudes in type II string models with matter fields localized at the intersections of D-brane wrapping cycles. The analysis of the three point amplitude is performed in the context…
We propose a scenario to obtain non-trivial Yukawa coupling matrices for the quark-lepton mass generation in supersymmetric intersecting D-brane models in type IIA T^6/Z_2 x Z_2 orientifold. As an example, an explicit model is constructed…
Recently, the complete landscape of three-family supersymmetric Pati-Salam models from intersecting D6-branes on a type IIA $\mathbb{T}^6/(\mathbb{Z}_2\times \mathbb{Z}_2)$ orientifold has been enumerated consisting of 33 independent models…
It is known that chiral fermions naturally appear at certain intersections of branes at angles. Motivated by this fact, we propose a string scenario in which different standard model gauge interactions propagate on different (intersecting)…
We analyse the structure of Yukawa couplings in local SU(5) F-theory models with $E_8$ enhancement. In this setting the $E_8$ symmetry is broken down to SU(5) by a 7-brane configuration described by T-branes, all the Yukawa couplings are…
String instanton Yukawa corrections from Euclidean D-branes are investigated in an effective Standard Model theory obtained from the minimal U(3)xU(2)xU(1) D-brane configuration. In the case of the minimal chiral and Higgs spectrum, it is…
We investigate lepton flavor violation in the context of intersecting D-brane models. We point out that these models have a source to generate flavor violation in the trilinear scalar couplings while the geometry of the construction leads…
Fermion masses and mixing, both in the quark and leptonic sector, are discussed within the approach to the Yukawa puzzle proposed by Arkani-Hamed and Schmaltz. In the quark sector we have shown that at least two extra dimensions are…
I discuss the calculation of the heavy generation masses in the superstring derived standard-like models. The top quark Yukawa coupling is obtained from a cubic level mass term while the bottom quark and tau lepton mass terms are obtained…
We construct a new set of intersecting D4-brane models that yield the (non-supersymmetric) standard model up to vector-like matter and, in some cases, extra U(1) factors in the gauge group. The models are constrained by the requirement that…
We built an extended 2HDM theory with a spontaneously broken $U(1) _{X}$ global symmetry, where the tree level Universal Seesaw Mechanism generates the mass hierarchy of the Standard Model charged fermions and the Zee-Babu mechanism…
We present a complete analysis of the fermion masses and mixing matrices in the framework of the little flavon model. In this model textures are generated by coupling the fermions to scalar fields, the little flavons, that are…
This technical note shows how Electrodynamics and a Yukawa model are dressed after integrating out perturbative brane fluctuations, and it is found that first order corrections in the inverse of the brane tension occur for the fermion and…
We construct a supersymmetric composite model in type IIA T^6/(Z_2 x Z_2) orientifold with intersecting D6-branes. Four generations of quarks and leptons are naturally emerged as composite fields at low energies. Two pairs of light…