18,404 research outputs found
Magnetic monopoles in a charged two-condensate Bose-Einstein system
We propose that a charged two-condensate Bose system possesses point-like
topological defects which can be interpreted as magnetic monopoles. By making
use of the -mapping theory, the topological charges of these magnetic
monopoles can be expressed in terms of the Hopf indices and Brouwer degree of
the -mapping.Comment: 4 page
750 GeV Resonance in the Gauged -Extended MSSM
Recently the ATLAS and CMS collaborations at the LHC announced their
observation of a potential 750 GeV di-photon resonance, after analyzing the
TeV LHC data. This observation has significant implications for
low-energy supersymmetry. Beyond the MSSM and the NMSSM, we study the
MSSM-extensions with an extra gauge symmetry. The anomaly cancellation
and the spontaneous breaking of the non-decoupled generically require
introducing vector-like supermultiplets (both colored and color-neutral ones)
and singlet supermultiplets, respectively. We illustrate that the potential 750
GeV resonance () can be accommodated in various mechanisms, as a
singlet-like scalar or pseudoscalar. Three benchmark scenarios are presented:
(1) vector-like quarks (VLQ) mediated ; (2) scalar
VLQ mediated ; (3) heavy scalar (pseudo-scalar)
associated production . Additionally, we notice
that the -mediated vector boson fusion production and -associated
production , if yielding a signal rate of the observed level,
might have been excluded by the searches for via Drell-Yan process at the
LHC.Comment: v3, figure update with corresponding modification in discussion,
version accepted by PL
Complete One-Loop Matching for a Singlet Scalar in the Standard Model EFT
We present the results of the first complete one-loop matching calculation
between the real singlet scalar extension of the Standard Model and the
Standard Model effective field theory (SMEFT) at dimension six. Beyond their
immediate relevance to the precision calculation of observables in singlet
extensions of the Standard Model, our results illustrate a variety of general
features of one-loop matching. We explore the interplay between
non-supersymmetric non-renormalization theorems, the logarithmic dependence of
Wilson coefficients, and the relevance of mixed diagrams in theories with large
scale separation. In addition, we highlight some of the subtleties involved in
computing observables at next-to-leading order in SMEFT by mapping our results
to the parameter at one loop.Comment: 21 page
Ordering of geometrically frustrated classical and quantum Ising magnets
A systematic study of both classical and quantum geometric frustrated Ising
models with a competing ordering mechanism is reported in this paper. The
ordering comes in the classical case from a coupling of 2D layers and in the
quantum model from the quantum dynamics induced by a transverse field. By
mapping the Ising models on a triangular lattice to elastic lattices of
non-crossing strings, we derive an exact relation between the spin variables
and the displacement field of the strings. Using this map both for the
classical (2+1)D stacked model and the quantum frustrated 2D system, we obtain
a microscopic derivation of an effective Hamiltonian which was proposed before
on phenomenological grounds within a Landau-Ginzburg-Wilson approach. In
contrast to the latter approach, our derivation provides the coupling constants
and hence the entire transverse field--versus--temperature phase diagram can be
deduced, including the universality classes of both the quantum and the
finite--temperature transitions. The structure of the ordered phase is obtained
from a detailed entropy argument. We compare our predictions to recent
simulations of the quantum system and find good agreement. We also analyze the
connections to a dimer model on the hexagonal lattice and its height profile
representation, providing a simple derivation of the continuum free energy and
a physical explanation for the universality of the stiffness of the height
profile for anisotropic couplings.Comment: 15 pages, 7 figure
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