arXiv subjects

Y. Hosotani

Publications and source records attributed to Y. Hosotani.

17 recordsLinked to original sources

arXiv2009

Dynamical Electroweak Symmetry Breaking in SO(5)xU(1) Gauge-Higgs Unification with Top and Bottom Quarks

An SO(5)xU(1) gauge-Higgs unification model in the Randall-Sundrum warped space with top and bottom quarks is constructed. Additional fermions on the Planck brane make exotic particles heavy by effectively changing boundary conditions of bulk fermions from those determined by orbifold conditions. Gauge couplings of a top quark multiplet trigger electroweak symmetry breaking by the Hosotani mechanism, simultaneously giving a top quark the observed mass. The bottom quark mass is generated by combination of brane interactions and the Hosotani mechanism, where only one ratio of brane masses is relevant when the scale of brane masses is much larger than the Kaluza-Klein scale (\sim 1.5 TeV). The Higgs mass is predicted to be 49.9 (53.5) GeV for the warp factor 10^{15} (10^{17}). The Wilson line phase turns out π/2 and the Higgs couplings to W and Z vanish so that the LEP2 bound for the Higgs mass is evaded. In the flat spacetime limit the electroweak symmetry is unbroken.

hep-ph↗

arXiv2007

Two loop finiteness of Higgs mass and potential in the gauge-Higgs unification

The zero mode of an extra-dimensional component of gauge potentials serves as a 4D Higgs field in the gauge-Higgs unification. We examine QED on $M^4 \times S^1$ and determine the mass and potential of a 4D Higgs field (the $A_5$ component) at the two loop level with gauge invariant reguralization. It is seen that the mass is free from divergences and independent of the renormalization scheme.

hep-ph↗

arXiv2006

Gauge-Higgs Unification and Quark-Lepton Phenomenology in the Warped Spacetime

In the dynamical gauge-Higgs unification of electroweak interactions in the Randall-Sundrum warped spacetime the Higgs boson mass is predicted in the range 120 GeV -- 290 GeV, provided that the spacetime structure is determined at the Planck scale. Couplings of quarks and leptons to gauge bosons and their Kaluza-Klein (KK) excited states are determined by the masses of quarks and leptons. All quarks and leptons other than top quarks have very small couplings to the KK excited states of gauge bosons. The universality of weak interactions is slightly broken by magnitudes of $10^{-8}$, $10^{-6}$ and $10^{-2}$ for $μ$-$e$, $τ$-$e$ and $t$-$e$, respectively. Yukawa couplings become substantially smaller than those in the standard model, by a factor $|\cos \onehalf θ_W|$ where $θ_W$ is the non-Abelian Aharonov-Bohm phase (the Wilson line phase) associated with dynamical electroweak symmetry breaking.

hep-ph↗

arXiv2001

Cosmic Shells

When a potential for a scalar field has two local minima there arise spherical shell-type solutions of the classical field equations due to gravitational attraction. We establish such solutions numerically in a space which is asymptotically de Sitter. It generically arises when the energy scale characterizing the scalar field potential is much less than the Planck scale. It is shown that the mirror image of the shell appears in the other half of the Penrose diagram. The configuration is smooth everywhere with no physical singularity.

gr-qc↗

arXiv2000

False Vacuum Black Holes and Universes

We construct a black hole whose interior is the false vacuum and whose exterior is the true vacuum of a classical field theory. From the outside the metric is the usual Schwarzschild one, but from the inside the space is de Sitter with a cosmological constant determined by the energy of the false vacuum. The parameters of the field potential may allow for the false vacuum to exist for more than the present age of the universe. A potentially relevant effective field theory within the context of QCD results in a Schwarzschild radius of about 200 km.

gr-qc↗

arXiv2000

Monopoles, Dyons and Black Holes in the Four-Dimensional Einstein-Yang-Mills Theory

A continuum of monopole, dyon and black hole solutions exist in the Einstein-Yang-Mills theory in asymptotically anti-de Sitter space. Their structure is studied in detail. The solutions are classified by non-Abelian electric and magnetic charges and the ADM mass. The stability of the solutions which have no node in non-Abelian magnetic fields is established. There exist critical spacetime solutions which terminate at a finite radius, and have universal behavior. The moduli space of the solutions exhibits a fractal structure as the cosmological constant approaches zero.

hep-th↗

arXiv1998

Complex Monopoles in the Path Integral

Complex monopole configurations dominate in the path integral in the Georgi-Glashow-Chern-Simons model and disorder the Higgs vacuum. No cancellation is expected among Gribov copies of the monopole configurations.

hep-th↗

arXiv1998

Complex Monopoles and Gribov Copies

Complex monopole solutions exist in the three dimensional Georgi-Glashow model with the Chern-Simons term. They dominate the path integral and disorder the Higgs vacuum. Gribov copies of the vacuum and monopole configurations are studied in detail.

hep-th↗

arXiv1996

Aspects of Confinement and Chiral Dynamics in 2-d QED at Finite Temperature

We evaluate the Polyakov loop and string tension at zero and finite temperature in $QED_2.$ Using bozonization the problem is reduced to solving the Schrödinger equation with a particular potential determined by the ground state. In the presence of two sources of opposite charges the vacuum angle parameter $θ$ changes by $2π(q/e)$, independent of the number of flavors. This, in turn, alters the chiral condensate. Particularly, in the one flavor case through a simple computer algorithm, we explore the chiral dynamics of a heavy fermion.

hep-th↗

arXiv1996

Confinement and Chiral Dynamics in the Multi-flavor Schwinger Model

Two-dimensional QED with $N$ flavor fermions is solved at zero and finite temperature with arbitrary fermion masses to explore QCD physics such as chiral condensate and string tension. The problem is reduced to solving a Schrödinger equation for $N$ degrees of freedom with a specific potential determined by the ground state of the Schrödinger problem itself.

hep-th↗

arXiv1995

Massive multi-flavor Schwinger model at finite temperature and on compact space

The multi-flavor Schwinger model on $R^1$ at finite temperature $T$ is mathematically equivalent to the model on $S^1$ at $T=0$. The latter is reduced to a quantum mechanical system of $N-1$ degrees of freedom. Physics sensitively depends on the parameter $m/T$. Finite temperature behavior of the massive Schwinger model is quite different from that of the massless Schwinger model.

hep-ph↗

arXiv1995

The interplay between mass, volume, θ, and <\psibarψ> in N-flavor QED_2

The Schwinger model (QED_2) with N flavors of massive fermions on a circle of circumference L, or equivalently at finite temperature T, is reduced to a quantum mechanical system of N-1 degrees of freedom. With degenerate fermion masses (m) the chiral condensate develops a cusp singularity at $θ=\pm π$ in the limit L -> $\infty$ or T -> 0, which is removed by a large asymmetry in the fermion masses. Physical quantities sensitively depend on the parameter mL or m/T, and the m -> 0 and L -> $\infty$ (or T -> 0) limits do not commute. A detailed analysis is given for N=3.

hep-th↗

arXiv1995

Spontaneous Magnetization in Lorentz Invariant Theories

In a class of three-dimensional Abelian gauge theories with both light and heavy fermions, heavy chiral fermions can trigger dynamical generation of a magnetic field, leading to the spontaneous breaking of the Lorentz invaiance. Finite masses of light fermions tend to restore the Lorentz invariance.

hep-th↗

arXiv1995

More About the Massive Multi-flavor Schwinger Model

The massive multi-flavor Schwinger model on a circle is reduced to a finite dimensional quantum mechanics problem. The model sensitively depends on the parameter $mL|\cos\onehalfθ|$ where $m$, $L$, and $θ$ are a typical fermion mass, the volume, and the vacuum angle, respectively.

hep-th↗

arXiv1995

The Massive Multi-flavor Schwinger Model

QED with N species of massive fermions on a circle of circumference L is analyzed by bosonization. The problem is reduced to the quantum mechanics of the 2N fermionic and one gauge field zero modes on the circle, with nontrivial interactions induced by the chiral anomaly and fermions masses. The solution is given for N=2 and fermion masses (m) much smaller than the mass of the U(1) boson with mass μ=\sqrt{2e^2/π} when all fermions satisfy the same boundary conditions. We show that the two limits m \go 0 and L \go \infty fail to commute and that the behavior of the theory critically depends on the value of mL|\cos\onehalfθ| where θis the vacuum angle parameter. When the volume is large μL \gg 1, the fermion condensate <\psibar ψ> is -(e^{4γ} mμ^2 \cos^4\onehalfθ/4π^3)^{1/3} or $-2e^γmμL \cos^2 \onehalfθ/π^2 for mL(μL)^{1/2} |\cos\onehalfθ| \gg 1 or \ll 1, respectively. Its correlation function decays algebraically with a critical exponent η=1 when m\cos\onehalfθ=0.

hep-th↗

arXiv1994

Reply to Hagen & Sudarshan's Comment

We show that the argument in Phys Rev Lett 70 (1993) 1360 is correct and consistent, and that Hagen & Sudarshan's solution has inconsistency leading to non-vanishing commutators of $[P^1, P^2]$ and $[P^j, H]$ even in physical states. This proves that many of HS's statements in their Comment are based merely on incorrect guess, but not on careful algebra.

hep-th↗

arXiv1993

Multiple Chern-Simons Fields on a Torus

Intertwined multiple Chern-Simons gauge fields induce matrix statistics among particles. We analyse this theory on a torus, focusing on the vacuum structure and the Hilbert space. The theory can be mimicked, although not completely, by an effective theory with one Chern-Simons gauge field. The correspondence between the Wilson line integrals, vacuum degeneracy and wave functions for these two theories are discussed. Further, it is obtained in both of these cases that the two total momenta and Hamiltonian commute only in the physical Hilbert space.

hep-th↗