3,911 research outputs found
A look inside charmed-strange baryons from lattice QCD
The electromagnetic form factors of the spin-3/2 baryons, namely
, , and , are
calculated in full QCD on PACS-CS lattices with a pion mass of
156(9) MeV. The electric charge radii and magnetic moments from the and
multipole form factors are extracted. Results for the electric quadrupole
form factors, , are also given. Quark sector contributions are computed
individually for each observable and then combined to obtain the baryon
properties. We find that the charm quark contributions are systematically
smaller than the strange-quark contributions in the case of the charge radii
and magnetic moments. moments of the and
provide a statistically significant data to conclude that their electric charge
distributions are deformed to an oblate shape. Properties of the spin-1/2
and baryons are also computed and a thorough
comparison is given. This complete study gives valuable hints about the
heavy-quark dynamics in charmed hadrons.Comment: 14 pages, 14 figures. Includes a subsection on the systematic effect
Examining prejudice reduction through solidarity and togetherness experiences among Gezi Park activists in Turkey
Prejudice reduction research has focused on reducing negative regard as a means to improve relations between various groups (e.g., religious, ethnic, political). Though positive regard between groups may be created, these forms of contact and common identification do not alter policy orientations of advantaged groups toward disadvantaged ones. Rather than intergroup contact, it is suggested that a collective action model of prejudice reduction (Dixon, J., Levine, M., Reicher, S., & Durrheim, K. (2012). Beyond prejudice: Are negative evaluations the problem and is getting us to like one another more the solution? Behavioral and Brain Sciences, 35, 411-425) would create ties between disadvantaged groups to work toward beneficial policy change. We seek to show that the Gezi Park protests in Taksim, İstanbul functioned as an intergroup phenomenon, requiring the cooperation of a number of disadvantaged groups (e.g., feminists, Kurds) working together to improve the status of all present. In a series of interviews with 34 activists from the Gezi Park protests, participants were to reflect on their individual and group-based experiences during their time in the Gezi Park protests. Data indicate that although a few groups remained distant or disconnected during the protests, a common ground was achieved such that some participants were able to overcome past prejudices. Data also indicate that through group perceptions and individuals’ descriptions of events, groups who had previously not been able to cooperate were able to work and stick together at Gezi. Results also imply, in line with Dixon et al. (2012), that if disadvantaged groups work together, they might change the position of their groups and improve each group’s disadvantaged position via collective action
Traveling waves in one-dimensional nonlinear models of strain-limiting viscoelasticity
In this article we investigate traveling wave solutions of a nonlinear
differential equation describing the behaviour of one-dimensional viscoelastic
medium with implicit constitutive relations. We focus on a subclass of such
models known as the strain-limiting models introduced by Rajagopal. To describe
the response of viscoelastic solids we assume a nonlinear relationship among
the linearized strain, the strain rate and the Cauchy stress. We then
concentrate on traveling wave solutions that correspond to the heteroclinic
connections between the two constant states. We establish conditions for the
existence of such solutions, and find those solutions, explicitly, implicitly
or numerically, for various forms of the nonlinear constitutive relation
CP violation in and LFV
The CMS collaboration has reported a possible lepton flavour violating (LFV)
signal . Whereas this does not happen in the standard model (SM),
we point out that new physics responsible for this type of decay would, in
general, also produce charge-parity (CP) violation in . We
estimate the size of this effect in a model independent manner and find that a
large asymmetry, of order 25\%, is allowed by current constraints.Comment: RevTex, 6 pages with one figure. Typos corrected and figure update
Instability and stability properties of traveling waves for the double dispersion equation
In this article we are concerned with the instability and stability
properties of traveling wave solutions of the double dispersion equation
for ,
. The main characteristic of this equation is the existence of two
sources of dispersion, characterized by the terms and . We
obtain an explicit condition in terms of , and on wave velocities
ensuring that traveling wave solutions of the double dispersion equation are
strongly unstable by blow up. In the special case of the Boussinesq equation
(), our condition reduces to the one given in the literature. For the
double dispersion equation, we also investigate orbital stability of traveling
waves by considering the convexity of a scalar function. We provide both
analytical and numerical results on the variation of the stability region of
wave velocities with , and and then state explicitly the conditions
under which the traveling waves are orbitally stable.Comment: 16 pages, 4 figure
T-odd correlations from top-quark CEDM in lepton plus jets top-pair events
There exist several recent studies of the top-quark CEDM in the context of
searching for CP violating signals in top-quark pair production at the LHC.
Most of these studies constrain the CEDM either from deviations in the top-pair
cross section from its standard model value, or from T-odd asymmetries in the
dimuon channel. Motivated by ATLAS and CMS interest, we extend the study of
T-odd asymmetries to the lepton plus jets channel. At the parton level, using
MadGraph, we identify the most promising signals and their statistical
sensitivity. We find that the signals with larger sensitivity to the CEDM
require distinguishing between and jets and propose a simple way
to address this.Comment: 12 pages, 2 tables, 1 figur
Probabilistic Logic Programming with Beta-Distributed Random Variables
We enable aProbLog---a probabilistic logical programming approach---to reason
in presence of uncertain probabilities represented as Beta-distributed random
variables. We achieve the same performance of state-of-the-art algorithms for
highly specified and engineered domains, while simultaneously we maintain the
flexibility offered by aProbLog in handling complex relational domains. Our
motivation is that faithfully capturing the distribution of probabilities is
necessary to compute an expected utility for effective decision making under
uncertainty: unfortunately, these probability distributions can be highly
uncertain due to sparse data. To understand and accurately manipulate such
probability distributions we need a well-defined theoretical framework that is
provided by the Beta distribution, which specifies a distribution of
probabilities representing all the possible values of a probability when the
exact value is unknown.Comment: Accepted for presentation at AAAI 201
Quasistatic nonlinear viscoelasticity and gradient flows
We consider the equation of motion for one-dimensional nonlinear
viscoelasticity of strain-rate type under the assumption that the stored-energy
function is -convex, which allows for solid phase transformations. We
formulate this problem as a gradient flow, leading to existence and uniqueness
of solutions. By approximating general initial data by those in which the
deformation gradient takes only finitely many values, we show that under
suitable hypotheses on the stored-energy function the deformation gradient is
instantaneously bounded and bounded away from zero. Finally, we discuss the
open problem of showing that every solution converges to an equilibrium state
as time and prove convergence to equilibrium under a
nondegeneracy condition. We show that this condition is satisfied in particular
for any real analytic cubic-like stress-strain function.Comment: 40 pages, 1 figur
Tensor form factors of nucleon in QCD
We extract the isovector tensor nucleon form factors, which play an important
role in understanding the transverse spin structure of the nucleon when related
to the quark helicity-flip generalized parton distributions via their first
moments. We employ the light-cone QCD sum rules to leading order in QCD and
include distribution amplitudes up to twist 6 in order to calculate the three
tensor form factors , and . Our results agree well with
those from other approaches in the low and high momentum-transfer regions.Comment: 8 pages, 1 figure; minor changes, matches journal versio
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