34 research outputs found
Dynamical Restoration of Z_N Symmetry in SU(N)+Higgs Theories
We study the Z_N symmetry in SU(N)+Higgs theories with the Higgs field in the
fundamental representation. The distributions of the Polyakov loop show that
the Z_N symmetry is explicitly broken in the Higgs phase. On the other hand,
inside the Higgs symmetric phase the Polyakov loop distributions and other
physical observables exhibit the Z_N symmetry. This effective restoration of
the Z_N symmetry changes the nature of the confinement-deconfinenement
transition. We argue that the Z_N symmetry will lead to time independent
topological defect solutions in the Higgs symmetric deconfined phase which will
play important role at high temperatures.Comment: 13 pages, 4 figure
Stabilisation of Seven Directions in an Early Universe M -- theory Model
Our model consists of intersecting 22'55' branes in M theory distributed
uniformly in the common transverse space. Equations of state follow from U
duality symmetries. In this model, three spatial directions expand, and seven
directions stabilise to constant sizes. From string theory perspective, the
dilaton is hence stabilised. The constant sizes depend on certain imbalance
among initial values. One naturally obtains M_{11} \simeq M_s \simeq M_4 and
g_s \simeq 1 within a few orders of magnitude. Smaller numbers, for example M_s
\simeq 10^{- 16} M_4, are also possible but require fine tuning.Comment: 11 Pagesl. Latex file. Version 2: Minor changes and a reference
added. Version 3: Title changed; many textual modifications, mainly to keep
within journal's length constraints, and to explain the differences between
brane gas models and intersecting brane configurations used here; references
added. To appear in Physical Review D (Rapid communications
Meta-stable States in Quark-Gluon Plasma
We study the meta-stable states in high temperature phase of QCD
characterised by nonzero expectation values for the imaginary part of the
Polyakov loop. We consider dynamical staggered quarks, and carry
out simulations at various values of the coupling to observe these
states. In particular, we find the value of the coupling () above
which the meta-stable states appear. The resulting value of
corresponds to temperature MeV for .Comment: This version includes new simulations carried out on bigger lattices,
particularly on and $32^3 x 6
Parametric resonance of complex scalar field under spacetime oscillations
In this proceeding, we study time evolution of a complex scalar field, in
symmetry broken phase, in presence of oscillating spacetime metric background.
We show that spacetime oscillations lead to parametric resonance of the field.
This generates excitations in the field for a wide range of frequency of
spacetime oscillations which ultimately lead to the formation of topological
vortices. The lowest frequency cut-off to induce this phenomena is set by
system size due to finite size effects.Comment: 4 pages, 3 figures, Contribution to proceedings of XXIV DAE-BRNS
Symposium on High Energy Physics, Dec. 14-18, 2020, Jatni, Odisha, Indi