Symmetry breaking caused by large ℛ-charge

We discuss the gauge symmetry breaking via the Hosotani mechanism by using exact results on supersymmetric gauge theories based on the localization method. We use the theories on S 2 × S 1 Euclidean space, and study how the effective potential for the Wilson line phase varies by running an imaginary chemical potential. In order to break the symmetry, we find that large ℛ-charge is necessary. With such large ℛ-charge, we study the phase structure of the theory. In addition, we observed that a finite size effect on our curved space when we take ℛ-charge is not so large

Universal turbulence on branes in holography

At a meson melting transition in holographic QCD, a weak turbulence of mesons was found with critical embeddings of probe D-branes in gravity duals. The turbulent mesons have a power-law energy distribution ε n ∝ ( ω n ) α where ω n is the mass of the n -th excited resonance of the meson tower. In this paper, we find that the turbulence power α is universal, irrespective of how the transition is driven, by numerically calculating the power in various static brane setups at criticality. We also find that the power α depends only on the cone dimensions of the probe D-branes

Linear programming analysis of the R -parity violation within EDM-constraints

The constraint on the R -parity violating supersymmetric interactions is discussed in the light of current experimental data of the electric dipole moment of neutron, 129 Xe , 205 Tl, and 199 Hg atoms, and YbF and ThO molecules. To investigate the constraints without relying upon the assumption of the dominance of a particular combination of couplings over all the rest, an extensive use is made of the linear programming method in the scan of the parameter space. We give maximally possible values for the EDMs of the proton, deuteron, 3 He nucleus, 211 Rn, 225 Ra, 210 Fr, and the R -correlation of the neutron beta decay within the constraints from the current experimental data of the EDMs of neutron, 129 Xe, 205 Tl, and 199 Hg atoms, and YbF and ThO molecules using the linear programming method. It is found that the R -correlation of the neutron beta decay and hadronic EDMs are very useful observables to constrain definite regions of the parameter space of the R -parity violating supersymmetry

The formulation of gauge-Higgs unification with dynamical boundary conditions

The boundary conditions on multiply connected extra dimensions play major roles in gauge-Higgs unification theory. Different boundary conditions, having been given in ad hoc manner so far, lead to different theories. To solve this arbitrariness problem of boundary conditions, we construct a formulation of gauge-Higgs unification with dynamics of boundary conditions on <math altimg="si1.gif" xmlns="http://www.w3.org/1998/Math/MathML"><msup><mrow><mi>M</mi></mrow><mrow><mn>4</mn></mrow></msup><mo>×</mo><msup><mrow><mi>S</mi></mrow><mrow><mn>1</mn></mrow></msup><mo stretchy="false">/</mo><msub><mrow><mi>Z</mi></mrow><mrow><mn>2</mn></mrow></msub></math> . As a result, it is found that only highly restricted sets of boundary conditions, which lead to nontrivial symmetry breaking, practically contribute to the partition function. In particular, we show that for <math altimg="si2.gif" xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi mathvariant="italic">SU</mi></mrow><mo stretchy="false">(</mo><mn>5</mn><mo stretchy="false">)</mo></math> gauge group, sets of boundary conditions which lead to <math altimg="si3.gif" xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi mathvariant="italic">SU</mi></mrow><mo stretchy="false">(</mo><mn>5</mn><mo stretchy="false">)</mo><mo stretchy="false">→</mo><mrow><mi mathvariant="italic">SU</mi></mrow><mo stretchy="false">(</mo><mn>3</mn><mo stretchy="false">)</mo><mo>×</mo><mrow><mi mathvariant="italic">SU</mi></mrow><mo stretchy="false">(</mo><mn>2</mn><mo stretchy="false">)</mo><mo>×</mo><mi>U</mi><mo stretchy="false">(</mo><mn>1</mn><mo stretchy="false">)</mo></math> symmetry breaking are naturally included in the restricted sets

Spectroscopy of family gauge bosons

Spectroscopy of family gauge bosons is investigated based on a U(3) family gauge boson model proposed by Sumino. In his model, the family gauge bosons are in mass eigenstates in a diagonal basis of the charged lepton mass matrix. Therefore, the family numbers are defined by (e1,e2,e3)=(e,μ,τ) , while the assignment for quark sector are free. For possible family-number assignments (q1,q2,q3) , under a constraint from K0 – K¯0 mixing, we investigate possibilities of new physics, e.g. production of the lightest family gauge boson at the LHC, μ−N→e−N , rare K and B decays, and so on

Chiral ground states in a frustrated holographic superconductor

Frustration is an important phenomenon in condensed matter physics because it can introduce a new order parameter such as chirality. Towards understanding a mechanism of the frustration in strongly correlated systems, we study a holographic superconductor model with three scalar fields and an interband Josephson coupling, which is important for the frustration. We analyze free energy of solutions of the model to determine ground states. We find chiral ground states, which have nonzero chirality

Phase diagram of a holographic superconductor model with s-wave and d-wave

We consider a holographic model with a scalar field, a tensor field and a direct coupling between them as a superconductor with an s-wave and a d-wave. We find a rich phase structure in the model. The model exhibits a phase of coexistence of the s-wave and the d-wave, or a phase of an order competition. Furthermore, it has a triple point

Electromagnetic instability in holographic QCD

Using the AdS/CFT correspondence, we calculate the vacuum decay rate for the Schwinger effect in confining large N c gauge theories. The instability is induced by thecorrespondence, we calculate the vacuum quark antiquark pair creation triggered by strong electromagnetic fields. The decay rate is obtained as the imaginary part of the Euler-Heisenberg effective Lagrangian evaluated from the D-brane action with a constant electromagnetic field in holographic QCD models such as the Sakai-Sugimoto model and the deformed Sakai-Sugimoto model. The decay rate is found to increase with the magnetic field parallel to the electric field, while it decreases with the magnetic field perpendicular to the electric field. We discuss generic features of a critical electric field as a function of the magnetic field and the QCD string tension in the Sakai-Sugimoto model

Position space formulation for Dirac fermions on honeycomb lattice

We study how to construct Dirac fermion defined on the honeycomb lattice in position space. Starting from the nearest neighbor interaction in tight binding model, we show that the Hamiltonian is constructed by kinetic term and second derivative term of three flavor Dirac fermions in which one flavor has a mass of cutoff order and the other flavors are massless. In this formulation, the structure of the Dirac point is simplified so that its uniqueness can be easily shown even if we consider the next-to-nearest neighbor interaction. We also show that there is a hidden exact <math altimg="si1.gif" xmlns="http://www.w3.org/1998/Math/MathML"><mi>U</mi><mo stretchy="false">(</mo><mn>1</mn><mo stretchy="false">)</mo></math> symmetry (flavor–chiral symmetry) at finite lattice spacing, which protects the masslessness of the Dirac fermion, and discuss the analogy with the staggered fermion formulation

Affine SU( N ) algebra from wall-crossings

We study the relation between the instanton counting on ALE spaces and the BPS state counting on a toric Calabi-Yau three-fold. We put a single D4-brane on a divisor isomorphic to A N −1 -ALE space in the Calabi-Yau three-fold, and evaluate the discrete changes of BPS partition function of D4-D2-D0 states in the wall-crossing phenomena. In particular, we find that the character of affine SU( N ) algebra naturally arises in wall-crossings of D4-D2-D0 states. Our analysis is completely based on the wall-crossing formula for the d = 4, N $$\mathcal{N}$$ = 2 supersymmetric theory obtained by dimensionally reducing the Calabi-Yau three-fold