605 research outputs found
Analysis of and with QCD sum rules
In this article, we calculate the masses and the pole residues of the
heavy baryons and with the QCD
sum rules. The numerical values (or
) and (or ) are in good agreement
with the experimental data.Comment: 18 pages, 18 figures, slight revisio
Active Amplification of the Terrestrial Albedo to Mitigate Climate Change: An Exploratory Study
This study explores the potential to enhance the reflectance of solar
insolation by the human settlement and grassland components of the Earth's
terrestrial surface as a climate change mitigation measure. Preliminary
estimates derived using a static radiative transfer model indicate that such
efforts could amplify the planetary albedo enough to offset the current global
annual average level of radiative forcing caused by anthropogenic greenhouse
gases by as much as 30 percent or 0.76 W/m2. Terrestrial albedo amplification
may thus extend, by about 25 years, the time available to advance the
development and use of low-emission energy conversion technologies which
ultimately remain essential to mitigate long-term climate change. However,
additional study is needed to confirm the estimates reported here and to assess
the economic and environmental impacts of active land-surface albedo
amplification as a climate change mitigation measure.Comment: 21 pages, 3 figures. In press with Mitigation and Adaptation
Strategies for Global Change, Springer, N
Single-cell analysis of early chick hypothalamic development reveals that hypothalamic cells are induced from prethalamic-like progenitors
The hypothalamus regulates many innate behaviors, but its development remains poorly understood. Here, we used single-cell RNA sequencing (RNA-seq) and hybridization chain reaction (HCR) to profile multiple stages of early hypothalamic development in the chick. Hypothalamic neuroepithelial cells are initially induced from prethalamic-like cells. Two distinct hypothalamic progenitor populations then emerge and give rise to tuberal and mammillary/paraventricular hypothalamic cells. At later stages, the regional organization of the chick and mouse hypothalamus is highly similar. We identify selective markers for major subdivisions of the developing chick hypothalamus and many previously uncharacterized candidate regulators of hypothalamic induction, regionalization, and neurogenesis. As proof of concept for the power of the dataset, we demonstrate that prethalamus-derived follistatin inhibits hypothalamic induction. This study clarifies the organization of the nascent hypothalamus and identifies molecular mechanisms that may control its induction and subsequent development
Effects of Large CP violating phases on g_{\m}-2 in MSSM
Effects of CP violation on the supersymmetric electro-weak correction to the
anomalous magnetic moment of the muon are investigated with the most general
allowed set of CP violating phases in MSSM. The analysis includes contributions
from the chargino and the neutralino exchanges to the muon anomaly. The
supersymmetric contributions depend only on specific combinations of CP phases.
The independent set of such phases is classified. We analyse the effects of the
phases under the EDM constraints and show that large CP violating phases can
drastically affect the magnitude of the supersymmetric electro-weak
contribution to and may even affect its overall sign.Comment: 26 pages Latex file including 4 figure
Gamma-Ray Bursts: The Underlying Model
A pedagogical derivation is presented of the ``fireball'' model of gamma-ray
bursts, according to which the observable effects are due to the dissipation of
the kinetic energy of a relativistically expanding wind, a ``fireball.'' The
main open questions are emphasized, and key afterglow observations, that
provide support for this model, are briefly discussed. The relativistic outflow
is, most likely, driven by the accretion of a fraction of a solar mass onto a
newly born (few) solar mass black hole. The observed radiation is produced once
the plasma has expanded to a scale much larger than that of the underlying
``engine,'' and is therefore largely independent of the details of the
progenitor, whose gravitational collapse leads to fireball formation. Several
progenitor scenarios, and the prospects for discrimination among them using
future observations, are discussed. The production in gamma- ray burst
fireballs of high energy protons and neutrinos, and the implications of burst
neutrino detection by kilometer-scale telescopes under construction, are
briefly discussed.Comment: In "Supernovae and Gamma Ray Bursters", ed. K. W. Weiler, Lecture
Notes in Physics, Springer-Verlag (in press); 26 pages, 2 figure
Rare Decays of \Lambda_b->\Lambda + \gamma and \Lambda_b ->\Lambda + l^{+} l^{-} in the Light-cone Sum Rules
Within the Standard Model, we investigate the weak decays of and with the light-cone
sum rules approach. The higher twist distribution amplitudes of
baryon to the leading conformal spin are included in the sum rules for
transition form factors. Our results indicate that the higher twist
distribution amplitudes almost have no influences on the transition form
factors retaining the heavy quark spin symmetry, while such corrections can
result in significant impacts on the form factors breaking the heavy quark spin
symmetry. Two phenomenological models (COZ and FZOZ) for the wave function of
baryon are also employed in the sum rules for a comparison, which can
give rise to the form factors approximately 5 times larger than that in terms
of conformal expansion. Utilizing the form factors calculated in LCSR, we then
perform a careful study on the decay rate, polarization asymmetry and
forward-backward asymmetry, with respect to the decays of , .Comment: 38 pages, 15 figures, some typos are corrected and more references
are adde
An analytical biomarker for treatment of patients with recurrent B-ALL after remission induced by infusion of anti-CD19 chimeric antigen receptor T (CAR-T) cells
Light cone QCD sum rules study of the semileptonic heavy and transitions to and baryons
The semileptonic decays of heavy spin--1/2, and
baryons to the light spin-- 1/2, and baryons are investigated
in the framework of the light cone QCD sum rules. In particular, using the most
general form of the interpolating currents for the heavy baryons as well as the
distribution amplitudes of the and baryons, we calculate all
form factors entering the matrix elements of the corresponding effective
Hamiltonians in full QCD. Having calculated the responsible form factors, we
evaluate the decay rates and branching fractions of the related transitions.Comment: 30 Pages, 5 Figures and 18 Table
Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment
This paper describes an analysis of the angular distribution of W->enu and
W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with
the ATLAS detector at the LHC in 2010, corresponding to an integrated
luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and
the missing transverse energy, the W decay angular distribution projected onto
the transverse plane is obtained and analysed in terms of helicity fractions
f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV
and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw
> 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour,
are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017
+/- 0.030, where the first uncertainties are statistical, and the second
include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables,
revised author list, matches European Journal of Physics C versio
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