41,966 research outputs found
Anomalous Higgs Couplings
We review the effects of new effective interactions on the Higgs boson
phenomenology. New physics in the electroweak bosonic sector is expected to
induce additional interactions between the Higgs doublet field and the
electroweak gauge bosons leading to anomalous Higgs couplings as well as to
anomalous gauge-boson self-interactions. Using a linearly realized invariant effective Lagrangian to describe the bosonic sector of
the Standard Model, we review the effects of the new effective interactions on
the Higgs boson production rates and decay modes. We summarize the results from
searches for the new Higgs signatures induced by the anomalous interactions in
order to constrain the scale of new physics in particular at CERN LEP and
Fermilab Te vatron colliders.Comment: 35 pages, latex using epsfig.sty psfig.sty and axodraw.sty, 16
postscript figure
Large reduction with the Twisted Eguchi-Kawai model
We examine the breaking of symmetry recently reported for the Twisted
Eguchi-Kawai model (TEK). We analyse the origin of this behaviour and propose
simple modifications of twist and lattice action that could avoid the problem.
Our results show no sign of symmetry breaking and allow us to obtain values of
the large infinite volume string tension in agreement with extrapolations
from results based upon straightforward methods.Comment: latex file 14 pages, 4 figure
Charged-current inclusive neutrino cross sections in the SuperScaling model including quasielastic, pion production and meson-exchange contributions
Charged current inclusive neutrino-nucleus cross sections are evaluated using
the superscaling model for quasielastic scattering and its extension to the
pion production region. The contribution of two-particle-two-hole vector
meson-exchange current excitations is also considered within a fully
relativistic model tested against electron scattering data. The results are
compared with the inclusive neutrino-nucleus data from the T2K and SciBooNE
experiments. For experiments where GeV, the
three mechanisms considered in this work provide good agreement with the data.
However, when the neutrino energy is larger, effects from beyond the
also appear to be playing a role. The results show that processes induced by
two-body currents play a minor role at the kinematics considered.Comment: 10 pages, 7 figure
The Clustering of Extragalactic Extremely Red Objects
We have measured the angular and spatial clustering of 671 K5
Extremely Red Objects (EROs) from a 0.98 square degree sub-region of the NOAO
Deep Wide-Field Survey (NDWFS). Our study covers nearly 5 times the area and
has twice the sample size of any previous ERO clustering study. The wide field
of view and BwRIK passbands of the NDWFS allow us to place improved constraints
on the clustering of z=1 EROs. We find the angular clustering of EROs is
slightly weaker than in previous measurements, and w(1')=0.25+/-0.05 for
K<18.40 EROs. We find no significant correlation of ERO spatial clustering with
redshift, apparent color or absolute magnitude, although given the
uncertainties, such correlations remain plausible. We find the spatial
clustering of K5 EROs is well approximated by a power-law, with
r_0=9.7+/-1.1 Mpc/h in comoving coordinates. This is comparable to the
clustering of 4L* early-type galaxies at z<1, and is consistent with the
brightest EROs being the progenitors of the most massive ellipticals. There is
evidence of the angular clustering of EROs decreasing with increasing apparent
magnitude, when NDWFS measurements of ERO clustering are combined with those
from the literature. Unless the redshift distribution of K>20 EROs is very
broad, the spatial clustering of EROs decreases from r_0=9.7+/-1.1 Mpc/h for
K20 EROs.Comment: Accepted for publication in the ApJ. 29 pages with 10 figures. The
NOAO Deep Wide-Field Survey Bootes data release is available online at
http://www.noao.edu/noao/noaodeep
Steak Location Within the Semitendinosus Muscle Impacts Metmyoglobin Accumulation on Steaks During Retail Display
Beef color is a major attribute consumers utilize to make purchasing decisions. It is estimated poor color shelf-life of beef steaks costs the meat industry more than $1 billion annually. Shelf-life color is influenced by a balance of two biochemical processes within steaks: metmyoglobin reducing ability and oxygen consumption. Steaks that exhibit a greater metmyoglobin reducing and a reduced oxygen consumption are typically characterized as more color stable. Characteristics of the muscle fiber or muscle cell are what determine the properties of a steak. Commonly, muscles with more oxidative fibers have an elevated oxygen consumption and reduced metmyoglobin reducing ability. The Semitendinosus muscle or eye of round possesses a divergent muscle fiber isoform distribution based on the location steaks are fabricated. The objective of this study was to examine effects of steak location on muscle fiber type distribution and metmyoglobin accumulation of Semitendinosus steaks
Ghost excitonic insulator transition in layered graphite
Some unusual properties of layered graphite, including a linear energy
dependence of the quasiparticle damping and weak ferromagnetism at low doping,
are explained as a result of the proximity of a single graphene sheet to the
excitonic insulator phase which can be further stabilized in a doped system of
many layers stacked in the staggered () configuration
The role of spatial and temporal radiation deposition in inertial fusion chambers: the case of HiPER¿
The first wall armour for the reactor chamber of HiPER will have to face short energy pulses of 5 to 20 MJ mostly in the form of x-rays and charged particles at a repetition rate of 5–10 Hz. Armour material and chamber dimensions have to be chosen to avoid/minimize damage to the chamber, ensuring the proper functioning of the facility during its planned lifetime. The maximum energy fluence that the armour can withstand without risk of failure, is determined by temporal and spatial deposition of the radiation energy inside the material. In this paper, simulations on the thermal effect of the radiation–armour interaction are carried out with an increasing definition of the temporal and spatial deposition of energy to prove their influence on the final results. These calculations will lead us to present the first values of the thermo-mechanical behaviour of the tungsten armour designed for the HiPER project under a shock ignition target of 48 MJ. The results will show that only the crossing of the plasticity limit in the first few micrometres might be a threat after thousands of shots for the survivability of the armour
Some constraints on neutral heavy leptons from flavor-conserving decays of the Z boson
Small neutrino masses can arise in some grand unified models or superstring
theories. We consider a model with an enhanced fermion sector containing Dirac
neutral heavy leptons. The dependence on the mass and mixing parameters of
these new fermions is investigated for several measurable quantities. We study
the flavor-conserving leptonic decays of the Z boson and universality breaking
in these decays. We also consider the W boson mass dependence on neutral heavy
lepton parameters.Comment: 20 pages, Revtex 3.0, 6 uuencoded and compressed postscript figures
included. Compressed postscript file of paper, including figures, also
available by anonymous ftp at
ftp://ftp.physics.carleton.ca/pub/theory/gour/ocipc9411.ps.Z . Accepted for
publication in Phys. Rev. D
Magnetic field-induced insulating behavior in highly oriented pyrolitic graphite
We propose an explanation for the apparent semimetal-insulator transition
observed in highly oriented pyrolitic graphite in the presence of magnetic
field perpendicular to the layers. We show that the magnetic field opens an
excitonic gap in the linear spectrum of the Coulomb interacting quasiparticles,
in a close analogy with the phenomenon of dynamical chiral symmetry breaking in
the relativistic theories of the 2+1-dimensional Dirac fermions. Our
strong-coupling appoach allows for a non-perturbative description of the
corresponding critical behavior
Measuring the deviation of the 2-3 lepton mixing from maximal with atmospheric neutrinos
The measurement of the deviation of the 2-3 leptonic mixing from maximal,
D_23 = 1/2 - sin^2(theta_23), is one of the key issues for understanding the
origin of the neutrino masses and mixing. In the three-neutrino context we
study the dependence of various observables in the atmospheric neutrinos on
D_23. We perform a global three-neutrino analysis of the atmospheric and
reactor neutrino data taking into account the effects of both the oscillations
driven by the "solar" parameters (Delta_m_21^2 and theta_12) and the 1-3
mixing. The departure from the one-dominant mass scale approximation results
into the shift of the 2-3 mixing from maximal by Delta_sin^2(theta_23) ~ 0.04,
so that D_23 ~ 0.04 +- 0.07 (1 sigma). Though value of the shift is not
statistically significant, the tendency is robust. The shift is induced by the
excess of the e-like events in the sub-GeV sample. We show that future large
scale water Cherenkov detectors can determine D_23 with accuracy of a few
percent, comparable with the sensitivity of future long baseline experiments.
Moreover, the atmospheric neutrinos will provide unique information on the sign
of the deviation (octant of theta_23).Comment: 20 pages, LaTeX2e file using RevTEX4, 6 figures and 1 table include
- …