1,917 research outputs found
Magnetic moments of decuplet baryons using effective quark masses in chiral constituent quark model
The magnetic moments of decuplet baryons have been
calculated in the chiral constituent quark model (CQM) with explicit
results for the contribution coming from the valence quark polarizations, sea
quark polarizations, and their orbital angular momentum. Since the
decuplet baryons have short lifetimes, the experimental
information about them is limited. The CQM has important implications for
chiral symmetry breaking as well as SU(3) symmetry breaking since it works in
the region between the QCD confinement scale and the chiral symmetry breaking
scale. The predictions in the model not only give a satisfactory fit when
compared with the experimental data but also show improvement over the other
models. The effect of the confinement on quark masses has also been discussed
in detail and the results of CQM are found to improve further with the
inclusion of effective quark masses.Comment: 21 pages. To appear in Phys. Rev. D. arXiv admin note: text overlap
with arXiv:1505.0330
Distinguishing Signatures of top-and bottom-type heavy vectorlike quarks at the LHC
An SU(2) vectorlike singlet quark with a charge either +2/3 (t') or -1/3 (b')
is predicted in many extensions of the Standard Model. The mixing of these
quarks with the top or bottom lead to Flavor Changing Yukawa Interactions and
Neutral Current. The decay modes of the heavier mass eigenstates are therefore
different from the Standard Model type chiral quarks. The Large Hadron Collider
(LHC) will provide an ideal environment to look for the signals of these exotic
quarks. Considering all decays, including those involving Z- and Yukawa
interactions, we show how one can distinguish between t' and b' from ratios of
event rates with different lepton multiplicities. The ability to reconstruct
the Higgs boson with a mass around 125.5 GeV plays an important role in such
differentiation.Comment: 18 pages, 10 figure
Near-optimal irrevocable sample selection for periodic data streams with applications to marine robotics
We consider the task of monitoring spatiotemporal phenomena in real-time by
deploying limited sampling resources at locations of interest irrevocably and
without knowledge of future observations. This task can be modeled as an
instance of the classical secretary problem. Although this problem has been
studied extensively in theoretical domains, existing algorithms require that
data arrive in random order to provide performance guarantees. These algorithms
will perform arbitrarily poorly on data streams such as those encountered in
robotics and environmental monitoring domains, which tend to have
spatiotemporal structure. We focus on the problem of selecting representative
samples from phenomena with periodic structure and introduce a novel sample
selection algorithm that recovers a near-optimal sample set according to any
monotone submodular utility function. We evaluate our algorithm on a seven-year
environmental dataset collected at the Martha's Vineyard Coastal Observatory
and show that it selects phytoplankton sample locations that are nearly optimal
in an information-theoretic sense for predicting phytoplankton concentrations
in locations that were not directly sampled. The proposed periodic secretary
algorithm can be used with theoretical performance guarantees in many real-time
sensing and robotics applications for streaming, irrevocable sample selection
from periodic data streams.Comment: 8 pages, accepted for presentation in IEEE Int. Conf. on Robotics and
Automation, ICRA '18, Brisbane, Australia, May 201
Curiosity Based Exploration for Learning Terrain Models
We present a robotic exploration technique in which the goal is to learn to a
visual model and be able to distinguish between different terrains and other
visual components in an unknown environment. We use ROST, a realtime online
spatiotemporal topic modeling framework to model these terrains using the
observations made by the robot, and then use an information theoretic path
planning technique to define the exploration path. We conduct experiments with
aerial view and underwater datasets with millions of observations and varying
path lengths, and find that paths that are biased towards locations with high
topic perplexity produce better terrain models with high discriminative power,
especially with paths of length close to the diameter of the world.Comment: 7 pages, 5 figures, submitted to ICRA 201
All two-qubit states that are steerable via Clauser-Horne-Shimony-Holt-type correlations are Bell nonlocal
We derive a new inequality that is necessary and sufficient to show
EPR-steering in a scenario employing only correlations between two arbitrary
dichotomic measurements on each party. Thus the inequality is a complete
steering analogy of the CHSH inequality, a generalisation of the result of
Cavalcanti et al, JOSA B, 32(4), A74 (2015). We show that violation of the
inequality only requires measuring over equivalence classes of mutually
unbiased measurements on the trusted party and in fact assuming a general two
qubit system arbitrary pairs of distinct projective measurements at the trusted
party are equally useful. Via this it is found that for a given state the
maximum violation of our EPR-steering inequality is equal to that for the CHSH
inequality, so all states that are EPR-steerable with CHSH-type correlations
are also Bell nonlocal.Comment: 5+4 pages. V2: close to journal version, simpler proof of steering
inequality, examine dichotomic POVM cas
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