On the phase diagram of the SU(2) adjoint Higgs model in 2+1 dimensions (original) (raw)
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On the phase diagram of the Higgs SU(2) model
The Higgs SU(2) model with fixed Higgs length is usually believed to have two different phases at high gauge coupling (\beta), separated by a line of first order transitions but not distinuguished by any typical symmetry associated with a local order parameter, as first proved by Fradkin and Shenker. We show that in regions of the parameter space where it is usually supposed to be a first order phase transition only a smooth crossover is in fact present.
Phase diagram of the lattice SU ( 2 ) Higgs model
Nucl Phys B, 2010
We perform a detailed study of the phase diagram of the lattice Higgs SU(2) model with fixed Higgs field length. Consistently with previsions based on the Fradkin-Shenker theorem we find a first order transition line with an endpoint whose position we determined. The diagram also shows cross-over lines: the cross-over corresponding to the pure SU(2) bulk is also present at nonzero coupling with the Higgs field and merges with the one that continues the line of first order transition beyond the critical endpoint. At high temperature the first order line becomes a crossover, whose position moves by varying the temperature.
Lattice studies at zero and finite temperature in the SU(2) Higgs model at small couplings
Physics Letters B, 1992
In the weak coupling region (fl= 8, 2 = 0.0017235 and 0.023705 ) the Higgs transition is determined on symmetrical (164) as well as thermal ( 163× ?¢~) lattices. This transition is weakly first order and becomes weaker for larger 2. Higgs and vector boson masses are obtained near to the phase transition, consistent with a mass ratio depending on 2 only. The transition temperature is obtained as a function of the Higgs mass. The results are compared with perturbative relations.
The finite-temperature phase transition in lattice SU(2) Higgs theory at weak couplings
Nuclear Physics B
In the weak-coupling region, at f3 = 8 and a A corresponding to an intermediate Fliggs mass, the Higgs transition is studied on asymmetric thermal (ts~x 2) lattices. A two-state signal is identified, indicating a first-order transition. Multihistogram and finite-size analysis are consistent with such a conclusion although the evidence is rather weak. The value of the Higgs condensate r(1~rjt) indicates a weakly first-order transition, in qualitative accordance with partially resummed perturbation theory. On the other hand, the latent heat and the metastability temperature range bT/T~ri exceed perturbative estimates by an order of magnitude. Higgs and vector boson masses are measured on symmetric lattices near the zero-temperature phase transition. The W-mass is found to he more sensitive to the lattice size than the Higgs mass. Masses and condensates are consistent with improved tree level relations within reasonable renormalized couplings.
Two-state signal at the confinement-higgs phase transition in the standard SU(2) higgs model
Physics Letters B, 1985
In a Monte Carlo calculation, numerical evidence is found for metastable coexisting phases in the variable length (h = 1.01 and fixed length (h = oo) SU(2) Higgs model with doublet scalar field. This supports earlier conjectures about the first ordei nature of the phase transition for finite gauge coupling (fl) and an arbitrary scalar self-coupling (X).
Studies of the phase in a U(1) gauge-Higgs model with global SU(2) symmetry
Nuclear Physics B, 1986
Properties of the phases in a gauge-Higgs model with SU(2)globu I ® U(l)lo,,al symmetry are investigated using a variety of probes. These include studies of the low-lying spectrum and measurement of a quantity that is sensitive to the breaking of the global SU(2) symmet~' and which provides useful information even on finite lattices. The strength of the effective gauge coupling and the ability (or lack thereof) of gauge interactions to induce chiral symmetry breaking is tested by evaluating {~+) in the quenched approximation for singly-charged fermions.
New order parameter for the Higgs transition in SU(2) -Higgs theory
Physical Review D
We investigate the Higgs transition within the four dimensional SU (2)− gauge-Higgs model in search for an order parameter as a function of the Higgs field hopping parameter, κ, using Lattice technique. We measure the Higgs condensate after applying Landau Gauge Fixing and study the corresponding susceptibility, magnetization and fourth order Binder cumulant using four different spatial volumes with N τ = 2. The computation is carried out with gauge coupling, β g = 8, for a range of scalar self-coupling, λ = {0.00010, 0.00350}, with emphasis near the critical end-point. Finite size scaling analysis of the gauge fixed condensate and its cumulants agree with the standard 3d Ising values ν = 0.62997, β/ν = 0.518, γ/ν = 1.964 at λ = 0.00150. These results are in agreement with previous studies suggesting 3d Ising universality class. The numerical results also indicate that, at the transition point, the gauge fixed condensate vanishes in the infinite volume limit.
2024
The lattice SU(2) gauge-scalar model with the scalar field in the adjoint representation of the gauge group has two completely separated confinement and Higgs phases according to the preceding studies based on numerical simulations that have been performed in the specific gauge fixing based on the conventional understanding of the Brout-Englert-Higgs mechanism. In this paper, we reexamine this phase structure in a gauge-independent way based on the numerical simulations performed without any gauge fixing. This is motivated to confirm the recently proposed gauge-independent Brout-Englert-Higgs mechanism for generating the mass of the gauge field without relying on any spontaneous symmetry breaking. For this purpose, we investigate correlations between gauge-invariant operators obtained by combining the original adjoint scalar field and the new field called the color-direction field which is constructed from the gauge field based on the gauge-covariant decomposition of the gauge field due to Cho-Duan-Ge-Shabanov and Faddeev-Niemi. Consequently, we reproduce gauge independently the transition line separating the confinement phase and the Higgs phase, and show surprisingly the existence of a new transition line that completely divides the confinement phase into two parts. Finally, we discuss the physical meaning of the new transition and the implications of the confinement mechanism.
Phase diagram of the lattice Higgs model
Nuclear Physics B, 2010
We perform a detailed study of the phase diagram of the lattice Higgs SU (2) model with fixed Higgs field length. Consistently with previsions based on the Fradkin-Shenker theorem we find a first order transition line with an endpoint whose position we determined. The diagram also shows cross-over lines: the cross-over corresponding to the pure SU (2) bulk is also present at nonzero coupling with the Higgs field and merges with the one that continues the line of first order transition beyond the critical endpoint. At high temperature the first order line becomes a crossover, whose position moves by varying the temperature.
Search for critical points in the SU(2) Higgs model
Physical Review D, 1990
We study the order of the Higgs phase transition in the SU(2) Higgs model at several values of the gauge coupling P for bare quartic coupling A, =0.5 using Monte Carlo simulations. We determine the internal energy of metastable states on various lattice sizes and estimate that the transition terminates at the critical point located at 1.95 & P, & 2. 25. We also apply a recently proposed multihistogram method in our data analysis. At P = 2. 25 and P= 2.4 our data strongly indicate the presence of a first-order phase transition. For P 2.6 we find no indication of a discontinuity in the internal energy on lattices up to size 16 and the transition is either weakly first order or of higher order.