971 research outputs found
TYC 1031 01262 1: The First Known Galactic Eclipsing Binary with a Type II Cepheid Component
We present the discovery and CCD observations of the first eclipsing binary
with a Type II Cepheid component in our Galaxy. The pulsation and orbital
periods are found to be 4.1523 and 51.38 days, respectively, i.e. this variable
is a system with the shortest orbital period among known Cepheid binaries.
Pulsations dominate the brightness variations. The eclipses are assumed to be
partial. The EB-subtype eclipsing light curve permits to believe that the
binary's components are non-spherical.Comment: 3 pages, 3 figures, accepted to MNRAS Letter
T-odd correlations from CP violating anomalous top-quark couplings revisited
We revisit the effect of CP violating anomalous top-quark couplings in
production and decay. We consider production through
gluon fusion (and light annihilation) followed by top-quark decay
into or . We find explicit analytic expressions for all the
triple products generated by the anomalous couplings that fully incorporate all
spin correlations. Our results serve as a starting point for numerical
simulations for the LHC.Comment: minor typos correcte
A Perturbative Realization of Miransky Scaling
Near conformal dynamics is employed in different extensions of the standard
model of particle interactions as well as in cosmology. Many of its interesting
properties are either conjectured or determined using model computations. We
introduce a relevant four dimensional gauge theory template allowing us to
investigate such dynamics perturbatively. The gauge theory we consider is
quantum chromodynamics with the addition of a meson-like scalar degree of
freedom as well as an adjoint Weyl fermion.
At the two-loop level, and in the Veneziano limit, we firmly establish the
existence of several fixed points of which one is all directions stable in the
infrared. An interesting feature of the model is that this fixed point is lost,
within the perturbatively trustable regime, by merging with another fixed point
when varying the number of quark flavors. We show the emergence of the Miransky
scaling and determine its properties. We are also able to determine the walking
region of the theory which turns out to be, at large number of colors, about
12% of the conformal window. Furthermore, we determine highly relevant
quantities for near conformal dynamics such as the anomalous dimension of the
fermion masses.Comment: 17 pages, 8 figure
Emergence of supersymmetry on the surface of three dimensional topological insulators
We propose two possible experimental realizations of a 2+1 dimensional
spacetime supersymmetry at a quantum critical point on the surface of three
dimensional topological insulators. The quantum critical point between the
semi-metallic state with one Dirac fermion and the s-wave superconducting state
on the surface is described by a supersymmetric conformal field theory within
-expansion. We predict the exact voltage dependence of the
differential conductance at the supersymmetric critical point.Comment: 8 pages, 2 figures; published versio
THIACALIX[4]ARENES DERIVATIVES: FROM SELF-ASSEMBY TO FUNCTIONAL MATERIALS
This work was supported by the by Russian Science Foundation, project # 19-13-00095
Cross-relaxation and phonon bottleneck effects on magnetization dynamics in LiYF4:Ho3+
Frequency and dc magnetic field dependences of dynamic susceptibility in
diluted paramagnets LiYF:Ho have been measured at liquid helium
temperatures in the ac and dc magnetic fields parallel to the symmetry axis of
a tetragonal crystal lattice. Experimental data are analyzed in the framework
of microscopic theory of relaxation rates in the manifold of 24
electron-nuclear sublevels of the lowest non-Kramers doublet and the first
excited singlet in the Ho ground multiplet split by the crystal
field of S symmetry. The one-phonon transition probabilities were computed
using electron-phonon coupling constants calculated in the framework of
exchange charge model and were checked by optical piezospectroscopic
measurements. The specific features observed in field dependences of the in-
and out-of-phase susceptibilities (humps and dips, respectively) at the
crossings (anti-crossings) of the electron-nuclear sublevels are well
reproduced by simulations when the phonon bottleneck effect and the cross-spin
relaxation are taken into account
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