492 research outputs found
On the Derivation of Vector Radiative Transfer Equation for Polarized Radiative Transport in Graded Index Media
Light transport in graded index media follows a curved trajectory determined
by the Fermat's principle. Besides the effect of variation of the refractive
index on the transport of radiative intensity, the curved ray trajectory will
induce geometrical effects on the transport of polarization ellipse. This paper
presents a complete derivation of vector radiative transfer equation for
polarized radiation transport in absorption, emission and scattering graded
index media. The derivation is based on the analysis of the conserved
quantities for polarized light transport along curved trajectory and a novel
approach. The obtained transfer equation can be considered as a generalization
of the classic vector radiative transfer equation that is only valid for
uniform refractive index media. Several variant forms of the transport equation
are also presented, which include the form for Stokes parameters defined with a
fixed reference and the Eulerian forms in the ray coordinate and in several
common orthogonal coordinate systems.Comment: This paper has been submitted to JQSR
Heavy Quark Spin Symmetry and Heavy Baryons: Electroweak Decays
Heavy quark spin symmetry is discussed in the context of single and doubly
heavy baryons. A special attention is paid to the constraints/simplifications
that this symmetry imposes on the non-relativistic constituent quark model wave
functions and on the b->c semileptonic decays of these hadrons.Comment: Presented at the 21st European Conference on Few-Body Problems in
Physics, Salamanca, Spain, 30 August - 3 September 201
P67 195. Cirugía del tromboembolismo pulmonar masivo en el enfermo crítico
La extracción de los trombos pulmonares en el tromboembolismo pulmonar masivo antes de 1953 (operación de Trendelenburg) cosechó fracaso tras fracaso. Desde el advenimiento de la circulación extracorpórea (CEC) el porcentaje de éxito de esta operación mejoró notablemente, no habiendo dejado de aumentar hasta la actualidad, existiendo series que reflejan porcentajes de hasta el 94% de supervivencia inmediata, con 86 y 83% de supervivencia actuarial a 1 y 3años.Presentamos un caso de paciente varón de 35años sin enfermedad previa ni antecedentes familiares de enfermedad tromboembólica. Consulta por insuficiencia respiratoria, siendo diagnosticado por tomografía computarizada de tromboembolismo en AP izquierda, la cual ocluye. El ECO-Doppler de MMII descarta trombosis venosa profunda (TVP). Una nueva tomografía computarizada informa de persistencia de la obstrucción de AP izquierda y sus ramas, que parece haber aumentado. En ecocardiografía transtorácica (ETT) dilatación de cavidades derechas con función de ventrículo derecho (VD) normal y presión sistólica de la arteria pulmonar (PSAP) de 70 mmHg. Los estudios para investigar trombofilia fueron negativos.Tras unos días empeora su situación, produciéndose dos paradas cardiorrespiratorias, de las que es reanimado y tratado inmediatamente con TNK. La tomografía computarizada muestra la existencia de nuevo episodio de tromboembolismo pulmonar que afecta a la AP derecha gravemente.Es intervenido quirúrgicamente bajo CEC sin parada circulatoria, extrayéndose molde trombótico de tronco y ambas ramas de la AP. La evolución postoperatoria fue favorable. En tomografía computarizada de control se observan limpios el tronco y las ramas de la AP, con cierto compromiso en ramas subsegmentarias de la AP izquierda.Se muestran imágenes de la intervención y tomografía computarizada pre y posquirúrgicas
Colour reconnections in Herwig++
We describe the implementation details of the colour reconnection model in
the event generator Herwig++. We study the impact on final-state observables in
detail and confirm the model idea from colour preconfinement on the basis of
studies within the cluster hadronization model. Moreover, we show that the
description of minimum bias and underlying event data at the LHC is improved
with this model and present results of a tune to available data.Comment: 19 pages, 21 figures, 2 tables. Matches with published versio
Efectos fisiológicos, agronómicos y económicos del riego con agua marina desalinizada en un cultivo de pomelo
La escasez de recursos hídricos para regadío en zonas áridas y semiáridas como el sureste español ha fomentado el uso de recursos hídricos no convencionales, entre los cuales el agua marina desalinizada (AMD) se ha convertido en el más prometedor para paliar la sobredemanda de agua. Sin embargo, las ventajas e inconvenientes de su uso complementario en el riego agrícola deben ser consi‐deradas. Este estudio evaluó la respuesta agrofisiológica de un cultivo de pomelo al riego con AMD durante tres años consecutivos. Se observaron diferencias significativas al comparar la calidad del AMD con los recursos convencionales de agua dulce disponibles, mayoritariamente procedentes del Trasvase Tajo‐Segura. Además, el estudio determinó el posible riesgo de sodicidad del suelo, las diferencias no significativas en las relaciones hídricas foliares y la elevada acumulación de boro en las hojas derivado del riego con AMD, comparado con el uso de recursos hídricos superficiales convencionales. Finalmente, una evaluación económica permitió analizar la rentabilidad de implantar total o parcialmente este re‐curso en el riego, considerando el coste del agua y del fertilizante y los ingresos obtenidos por la venta de la fruta. Los resultados proporcionan orientación para el uso y la gestión del AMD en zonas con escasez de recursos hídricos
Top Squarks and Bottom Squarks in the MSSM with Complex Parameters
We present a phenomenological study of top squarks (~t_1,2) and bottom
squarks (~b_1,2) in the Minimal Supersymmetric Standard Model (MSSM) with
complex parameters A_t, A_b, \mu and M_1. In particular we focus on the CP
phase dependence of the branching ratios of (~t_1,2) and (~b_1,2) decays. We
give the formulae of the two-body decay widths and present numerical results.
We find that the effect of the phases on the (~t_1,2) and (~b_1,2) decays can
be quite significant in a large region of the MSSM parameter space. This could
have important implications for (~t_1,2) and (~b_1,2) searches and the MSSM
parameter determination in future collider experiments. We have also estimated
the accuracy expected in the determination of the parameters of ~t_i and ~b_i
by a global fit of the measured masses, decay branching ratios and production
cross sections at e^+ e^- linear colliders with polarized beams. Analysing two
scenarios, we find that the fundamental parameters apart from A_t and A_b can
be determined with errors of 1% to 2%, assuming an integrated luminosity of 1
ab^-1 and a sufficiently large c.m.s. energy to produce also the heavier ~t_2
and ~b_2 states. The parameter A_t can be determined with an error of 2 - 3%,
whereas the error on A_b is likely to be of the order of 50%.Comment: 31 pages, 8 figures, comments and references added, conclusions
unchanged; version to appear in Phys. Rev.
Seventy-eight entire mitochondrial genomes and nuclear rRNA genes provide insight into the phylogeny of the hard ticks, particularly the Haemaphysalis species, Africaniella transversale and Robertsicus elaphensis
DATA AVAILABILITY : Data will be made available on request.Hoogstraal and Kim (1985) proposed from morphology, three groups of Haemaphysalis subgenera: (i) the
“structurally advanced”; (ii) the “structurally intermediate”; and (iii) the “structurally primitive” subgenera.
Nuclear gene phylogenies, however, did not indicate monophyly of these morphological groups but alas, only
two mitochondrial (mt) genomes from the “structurally intermediate” subgenera had been sequenced. The
phylogeny of Haemaphysalis has not yet been resolved. We aimed to resolve the phylogeny of the genus Haemaphysalis,
with respect to the subgenus Alloceraea. We presented 15 newly sequenced and annotated mt genomes
from 15 species of ticks, five species of which have not been sequenced before, and four new 18S rRNA
and 28S rRNA nuclear gene sequences. Our datasets were constructed from 10 mt protein-coding genes, cox1,
and the 18S and 28S nuclear rRNA genes. We found a 132-bp insertion between tRNA-Glu (E) gene and the nad1
gene in the mt genome of Haemaphysalis (Alloceraea) inermis that resembles insertions in H. (Alloceraea) kitaokai
and Rhipicephalus (Boophilus) geigyi. Our mt phylogenies had the three species of Amblyomma (Aponomma) we
sequenced embedded in the main clade of Amblyomma: Am. (Aponomma) fimbriatum, Am. (Aponomma) gervaisi
and Am. (Aponomma) latum. This is further support for the hypothesis that the evolution of eyes appears to have
occurred in the most-recent-common-ancestor of Amblyocephalus (i.e. Amblyomminae plus Rhipicephalinae)
and that eyes were subsequently lost in the most-recent-common-ancestor of the subgenus Am. (Aponomma).
Either Africaniella transversale or Robertsicus elaphensis, or perhaps Af. transversale plus Ro. elaphensis, appear to be
the sister-group to the rest of the metastriate Ixodida. Our cox1 phylogenies did not indicate monophyly of the
“structurally primitive”, “structurally intermediate” nor the “structurally advanced” groups of Haemaphysalis
subgenera. Indeed, the subgenus Alloceraea may be the only monophyletic subgenus of the genus Haemaphysalis
sequenced thus far. All of our mt genome and cox1 phylogenies had the subgenus Alloceraea in a clade that was
separate from the rest of the Haemaphysalis ticks. If Alloceraea is indeed the sister to the rest of the Haemaphysalis
subgenera this would resonate with the argument of Hoogstraal and Kim (1985), that Alloceraea was a subgenus
of “primitive” Haemaphysalis. Alectorobius capensis from Japan had a higher genetic-identity to A. sawaii, which
was also from Japan, than to the A. capensis from South Africa. This indicates that A. capensis from Japan may be
a cryptic species with respect to the A. capensis from South Africa.JSPS KAKENHI and the Japan Program for Infectious Diseases Research and Infrastructure from the Japan Agency for Medical Research and Development (AMED).https://www.elsevier.com/locate/ttbdisam2024Veterinary Tropical DiseasesNon
Limits on anomalous trilinear gauge boson couplings from WW, WZ and Wgamma production in pp-bar collisions at sqrt{s}=1.96 TeV
We present final searches of the anomalous gammaWW and ZWW trilinear gauge
boson couplings from WW and WZ production using lepton plus dijet final states
and a combination with results from Wgamma, WW, and WZ production with leptonic
final states. The analyzed data correspond to up to 8.6/fb of integrated
luminosity collected by the D0 detector in pp-bar collisions at sqrt{s}=1.96
TeV. We set the most stringent limits at a hadron collider to date assuming two
different relations between the anomalous coupling parameters
Delta\kappa_\gamma, lambda, and Delta g_1^Z for a cutoff energy scale Lambda=2
TeV. The combined 68% C.L. limits are -0.057<Delta\kappa_\gamma<0.154,
-0.015<lambda<0.028, and -0.008<Delta g_1^Z<0.054 for the LEP parameterization,
and -0.007<Delta\kappa<0.081 and -0.017<lambda<0.028 for the equal couplings
parameterization. We also present the most stringent limits of the W boson
magnetic dipole and electric quadrupole moments.Comment: 10 pages, 5 figures, submitted to PL
Evidence for an Excess of Soft Photons in Hadronic Decays of Z^0
Soft photons inside hadronic jets converted in front of the DELPHI main
tracker (TPC) in events of qqbar disintegrations of the Z^0 were studied in the
kinematic range 0.2 < E_gamma < 1 GeV and transverse momentum with respect to
the closest jet direction p_T < 80 MeV/c. A clear excess of photons in the
experimental data as compared to the Monte Carlo predictions is observed. This
excess (uncorrected for the photon detection efficiency) is (1.17 +/- 0.06 +/-
0.27) x 10^{-3} gamma/jet in the specified kinematic region, while the expected
level of the inner hadronic bremsstrahlung (which is not included in the Monte
Carlo) is (0.340 +/- 0.001 +/- 0.038) x 10^{-3} gamma/jet. The ratio of the
excess to the predicted bremsstrahlung rate is then (3.4 +/- 0.2 +/- 0.8),
which is similar in strength to the anomalous soft photon signal observed in
fixed target experiments with hadronic beams.Comment: 37 pages, 9 figures, Accepted by Eur. Phys. J.
- …