Results 1  10
of
48
Yukawa couplings in intersecting Dbrane models
 JHEP
"... Abstract: We compute the Yukawa couplings among chiral fields in toroidal Type II compactifications with wrapping D6branes intersecting at angles. Those models can yield realistic standard model spectrum living at the intersections. The Yukawa couplings depend both on the Kähler and open string mod ..."
Abstract

Cited by 76 (9 self)
 Add to MetaCart
(Show Context)
Abstract: We compute the Yukawa couplings among chiral fields in toroidal Type II compactifications with wrapping D6branes intersecting at angles. Those models can yield realistic standard model spectrum living at the intersections. The Yukawa couplings depend both on the Kähler and open string moduli but not on the complex structure. They arise from worldsheet instanton corrections and are found to be given by products of complex Jacobi theta functions with characteristics. The Yukawa couplings for a particular intersecting brane configuration yielding the chiral spectrum of the MSSM are computed as an example. We also show how our methods can be extended to compute Yukawa couplings on certain classes of elliptically fibered CY manifolds which are mirror to complex cones over del Pezzo surfaces. We find that the Yukawa couplings in intersecting D6brane models have a mathematical interpretation in the context of homological mirror symmetry. In particular, the computation of such Yukawa couplings is related to the construction of
Getting just the supersymmetric standard model at intersecting branes on the Z6orientifold
 INTERSECTING BRANES ON THE Z6ORIENTIFOLD, PHYS. REV. D70 (2004) 126010, HEPTH/0404055
, 2004
"... In this paper, globally N = 1 supersymmetric configurations of intersecting D6branes on the Z6 orientifold are discussed, involving also fractional branes. It turns out rather miraculously that one is led almost automatically to just one particular class of 5 stack models containing the SM gauge gr ..."
Abstract

Cited by 56 (12 self)
 Add to MetaCart
In this paper, globally N = 1 supersymmetric configurations of intersecting D6branes on the Z6 orientifold are discussed, involving also fractional branes. It turns out rather miraculously that one is led almost automatically to just one particular class of 5 stack models containing the SM gauge group, which all have the same chiral spectrum. The further discussion shows that these models can be understood as exactly the supersymmetric standard model without any exotic chiral symmetric/antisymmetric matter. The superpartner of the Higgs finds a natural explanation and the hypercharge remains massless. However, the nonchiral spectrum within the model class is very different and does not in all cases allow for a N = 2 low energy field theoretical understanding of the necessary breaking U(1) × U(1) → U(1) along the Higgs branch, which is needed in order to get the standard Yukawa couplings. Also the leftright symmetric models belong to exactly one class of chiral spectra, where the two kinds of exotic chiral fields can have the interpretation of forming a composite Higgs. The aesthetical beauty of these models, involving only nonvanishing intersection numbers of
Recombination of intersecting Dbranes by local tachyon condensation
 JHEP 0306
"... We provide a simple low energy description of recombination of intersecting Dbranes using super YangMills theory. The recombination is realized by condensation of an offdiagonal tachyonic fluctuation localized at the intersecting point. The recombination process is equivalent to braneantibrane a ..."
Abstract

Cited by 36 (1 self)
 Add to MetaCart
(Show Context)
We provide a simple low energy description of recombination of intersecting Dbranes using super YangMills theory. The recombination is realized by condensation of an offdiagonal tachyonic fluctuation localized at the intersecting point. The recombination process is equivalent to braneantibrane annihilation, thus our result confirms Sen’s conjecture on tachyon condensation, although we work in the super YangMills theory whose energy scale is much lower than α ′. We also discuss the decay width of nonparallelly separated Dbranes.
Intersecting brane models of particle physics and the Higgs mechanism
 JHEP 0207
"... Abstract: We analyze a recently constructed class of Dbrane theories with the fermion spectrum of the SM at the intersection of D6branes wrapping a compact toroidal space. We show how the SM Higgs mechanism appears as a brane recombination effect in which the branes giving rise to U(2)L × U(1) rec ..."
Abstract

Cited by 35 (8 self)
 Add to MetaCart
(Show Context)
Abstract: We analyze a recently constructed class of Dbrane theories with the fermion spectrum of the SM at the intersection of D6branes wrapping a compact toroidal space. We show how the SM Higgs mechanism appears as a brane recombination effect in which the branes giving rise to U(2)L × U(1) recombine into a single brane related to U(1)em. We also show how one can construct D6brane models which respect some supersymmetry at every intersection. These are quasisupersymmetric models of the type introduced in hepth/0201205 which may be depicted in terms of SUSYquivers and may stabilize the hierarchy between the weak scale and a fundamental scale of order 10100 TeV present in low string scale models. Several explicit D6brane models with three generation of quarks and leptons and different SUSYquiver structure are presented. One can prove on general grounds that if one wants to build a (factorizable) D6brane configuration with the SM gauge group and N = 1 SUSY (or quasiSUSY), also a massless (B −L) generator must be initially present in any model. If in addition we insist on left and righthanded fermions respecting the same N = 1 SUSY, the brane configurations are forced to have intersections giving rise to Higgs multiplets, providing for a rationale for the very existence of the SM Higgs sector. JHEP
An Improved Brane AntiBrane Action from Boundary Superstring Field Theory
 and MultiVortex Solutions”, JHEP 0301 (2003) 012, hepth/0211180
"... Abstract: We present an improved effective action for the DbraneantiDbrane system obtained from boundary superstring field theory. Although the action looks highly nontrivial, it has simple explicit multivortex (i.e. codimension2 multiBPS Dbrane) multiantivortex solutions. The solutions hav ..."
Abstract

Cited by 31 (7 self)
 Add to MetaCart
(Show Context)
Abstract: We present an improved effective action for the DbraneantiDbrane system obtained from boundary superstring field theory. Although the action looks highly nontrivial, it has simple explicit multivortex (i.e. codimension2 multiBPS Dbrane) multiantivortex solutions. The solutions have a curious degeneracy corresponding to different “magnetic ” fluxes at the core of each vortex. We also generalize the brane antibrane effective action that is suitable for the study of the inflationary scenario and the production of defects in the early universe. We show that when a brane and antibrane are distantly separated, although the system is classically stable it can decay via quantum tunneling through the barrier. Keywords: DBranes; Tachyon Condenstaion; Superstrings and Heterotic Strings;
Brane Inflation and Cosmic String Tension in Superstring Theory,” arXiv:hepth/0501099
"... Abstract. In a simple reanalysis of the KKLMMT scenario, we argue that the slow roll condition in the D3D3brane inflationary scenario in superstring theory requires ..."
Abstract

Cited by 30 (11 self)
 Add to MetaCart
(Show Context)
Abstract. In a simple reanalysis of the KKLMMT scenario, we argue that the slow roll condition in the D3D3brane inflationary scenario in superstring theory requires
D3/D7 inflationary model and Mtheory
 Phys. Rev. D
"... A proposal is made for a cosmological D3/D7 model with a constant magnetic flux along the D7 worldvolume. It describes an N = 2 gauge model with FayetIliopoulos terms and the potential of the hybrid Pterm inflation. The motion of the D3brane towards D7 in a phase with spontaneously broken supers ..."
Abstract

Cited by 29 (12 self)
 Add to MetaCart
(Show Context)
A proposal is made for a cosmological D3/D7 model with a constant magnetic flux along the D7 worldvolume. It describes an N = 2 gauge model with FayetIliopoulos terms and the potential of the hybrid Pterm inflation. The motion of the D3brane towards D7 in a phase with spontaneously broken supersymmetry provides a period of slowroll inflation in the de Sitter valley, the role of the inflaton being played by the distance between D3 and D7branes. After tachyon condensation a supersymmetric ground state is formed: a D3/D7 bound state corresponding to an Abelian nonlinear (noncommutative) instanton. In this model the existence of a nonvanishing cosmological constant is associated with the resolution of the instanton singularity. We discuss a possible embedding of this model into a compactified Mtheory setup. 1
Dynamical decay of braneantibrane and dielectric brane
, 2002
"... Using Dbrane effective field theories, we study dynamical decay of unstable brane systems: (i) a parallel braneantibrane pair with separation l and (ii) a dielectric brane. In particular we give explicitly the decay width of these unstable systems, and describe how the decay proceeds after the tun ..."
Abstract

Cited by 22 (1 self)
 Add to MetaCart
(Show Context)
Using Dbrane effective field theories, we study dynamical decay of unstable brane systems: (i) a parallel braneantibrane pair with separation l and (ii) a dielectric brane. In particular we give explicitly the decay width of these unstable systems, and describe how the decay proceeds after the tunnel effect. The decay (i) is analysed by the use of a tachyon effective action on the DpDp. A pair annihilation starts by nucleation of a bubble of a tachyon domain wall which represents a throat connecting these branes, and the tunneling decay width Γ is found to be proportional to ∼ exp(−lp+1TDp). We study also the decay leaving topological defects corresponding to lowerdimensional branes, which may be relevant for recent inflationary braneworld scenario. As for the decay (ii), first we observe that Dpbranes generically “curl up ” in a nontrivial RR field strength. Using this viewpoint, we compute the decay width of the dielectric D2branes by constructing relevant Euclidean bounce solutions in the shape of a funnel. We also give new solutions in doughnut shape which are involved with nucleation of dielectric branes from nothing.
Heating in brane inflation and hidden dark matter
, 2006
"... Towards the end of brane inflation, the brane pair annihilation produces massive closed strings. The transfer of this energy to Standard Model (SM) open string modes depends on where the SM branes and the brane annihilation are located: in the bulk, in the same throat or in different throats. We fi ..."
Abstract

Cited by 21 (6 self)
 Add to MetaCart
(Show Context)
Towards the end of brane inflation, the brane pair annihilation produces massive closed strings. The transfer of this energy to Standard Model (SM) open string modes depends on where the SM branes and the brane annihilation are located: in the bulk, in the same throat or in different throats. We find that, in all cases as long as the brane annihilation and the SM branes are not both in the bulk, the transfer of energy to start the hot big bang epoch can be efficient enough to be compatible with big bang nucleosynthesis. The suppression of the abundance of the graviton and its KaluzaKlein (KK) thermal relics follows from the warped geometry in flux compactification. This works out even in the scenarios where a long period of tunneling is expected. In the multithroat scenario, we find a dynamical mechnism of selecting a long throat as the SM throat. We establish three new dark matter candidates: KK modes with specific angular momentum in the SM throat, those in the brane annihilation throat, and different matters generated by KK modes tunneled to other throats. Since the latter two couple to the visible matter sector only through graviton mediation, they behave as hidden dark matter. Hidden dark matter has novel implications on the dark matter coincidence problem and the high energy cosmic rays.