相关论文: On the (Non) Perturbative Origin of Quark Masses i…
Non-perturbative superpotential cross-couplings between visible sector matter and K\"ahler moduli can lead to significant flavour-changing neutral currents in compactifications of type IIB string theory. Here, we compute corrections to…
We study U(N) SQCD with N_f <= N flavors of quarks and antiquarks by engineering it with a configuration of fractional D3-branes on a C^3 / Z_2 x Z_2 orbifold. In particular we show how the moduli space of the gauge theory naturally emerges…
We study models of fermion mass matrices based on a flavor- and generation-dependent string-motivated U(1)$_A$ gauge symmetry and report two new classes of solutions to the requisite consistency conditions. In particular, we propose that…
We propose a minimal embedding of the Standard Model spectrum in a D-brane configuration of type I string theory. The SU(3) color and SU(2) weak interactions arise from two different collections of branes. The model is neither grand unified…
We apply the well-known Scherk-Schwarz supersymmetry breaking mechanism in an open string context. We construct a new Z_3\times Z_3^\prime model, containing only D9-branes, and rederive from a more geometric perspective the known…
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…
We consider the most general generation-independent U(1) gauge symmetry consistent with the presence of Yukawa couplings for all quarks and leptons in the SUSY version of the Standard Model. This U(1) has generically mixed anomalies with SM…
D3-brane probes of E-type Yukawa points lead to strongly coupled nearly conformal sectors nearby the Standard Model (visible sector) which are motivated by F-theory GUTs. Realistic visible sector brane configurations induce a seesaw mass…
We propose several quark mass deformations of the holographic model of massless QCD using the D4/D8/D8bar brane configuration proposed by Sakai and Sugimoto. The deformations are based on introducing additional D4 or D6 branes away from the…
In F-theory GUT constructions Yukawa couplings necessarily take place at the intersection of three matter curves. For generic geometric configurations this gives rise to problematic Yukawa couplings unable to reproduce the observed…
In the extra U(1) superstring inspired model, we examine the electroweak and U(1)-prime symmetry breaking with the singlet and exotic quark D, D+{\c}along with the study of heavy Z-prime boson in accordance with the top quark mass region.…
Recently we provided a microscopic derivation of the exact supergravity profile for the twisted scalar field emitted by systems of fractional D3-branes at a Z2 orbifold singularity. In this contribution we focus on a set-up supporting an N…
We study the bulk effective theory of a class of orbifolds of the type IIB string with D5-branes, compactified to four dimensions. These constructions are connected, in a region of their moduli space, to some orbifolds of the type I and…
We elucidate certain aspects of F-theory gauge dynamics, due to quantum splitting of certain brane stacks, which are absent in the Type IIB limit. We also provide a working implementation of an algorithm for computing cohomology of line…
We propose an SU(5) GUT model extended with two additional pairs of $\mathbf{10}$ representation vector-like fermions. The CDF collaboration $W$ boson mass anomaly is explained by using the VEV of a real $\mathrm{SU(2)_L}$ triplet scalar…
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 are inspired by the facts that M-theory may reconcile the supersymmetric GUT scale with that of quantum gravity, and that it provides new avenues for low-energy supersymmetry breaking, to re-examine a flipped SU(5) model that has been…
We consider a 5D SUSY $SU(3)_c\times SU(2)_L\times U(1)_Y\times {\cal U}(1)$ model compactified on an $S^{(1)}/Z_2$ orbifold. To cancel anomalies arising from the presence of ${\cal U}(1)$, we employ a Chern-Simons term and also chiral…
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…
We consider the scenario in which the mass matrices of the charged fermions in the SO(10) Grand Unified Theory are generated exclusively by renormalizable Yukawa couplings to one $\mathbf{10} \oplus \mathbf{120}$ representation of scalars.…