Berry Phase of a Resonant State

We derive closed analytical expressions for the complex Berry phase of an open quantum system in a state which is a superposition of resonant states and evolves irreversibly due to the spontaneous decay of the metastable states. The codimension of an accidental degeneracy of resonances and the geometry of the energy hypersurfaces close to a crossing of resonances differ significantly from those of bound states. We discuss some of the consequences of these differences for the geometric phase factors, such as: Instead of a diabolical point singularity there is a continuous closed line of singularities formally equivalent to a continuous distribution of `magnetic' charge on a diabolical circle; different classes of topologically inequivalent non-trivial closed paths in parameter space, the topological invariant associated to the sum of the geometric phases, dilations of the wave function due to the imaginary part of the Berry phase and others.Comment: 28 pages Latex, three uuencoded postcript figure

Contribution of the Residual Body in the Spatial Organization of Toxoplasma gondii Tachyzoites within the Parasitophorous Vacuole

Toxoplasma gondii proliferates and organizes within a parasitophorous vacuole in rosettes around a residual body and is surrounded by a membranous nanotubular network whose function remains unclear. Here, we characterized structure and function of the residual body in intracellular tachyzoites of the RH strain. Our data showed the residual body as a body limited by a membrane formed during proliferation of tachyzoites probably through the secretion of components and a pinching event of the membrane at the posterior end. It contributes in the intravacuolar parasite organization by the membrane connection between the tachyzoites posterior end and the residual body membrane to give place to the rosette conformation. Radial distribution of parasites in rosettes favors an efficient exteriorization. Absence of the network and presence of atypical residual bodies in a ΔGRA2-HXGPRT knock-out mutant affected the intravacuolar organization of tachyzoites and their exteriorization

Macro-porous permeability aspects of MgSO4 salt hydrate foams for energy storage applications

In the present work a macroporous silicone foam, able to contain the magnesium sulfate, was chosen as matrix for the reversible hydration/dehydration process of the salt hydrate. The aim of the article was addressed towards the assessment of the relationship among microstructure, permeability and mass diffusion of the composite foam. This aspect represents an essential step for the future industrial development of this composite material. The results show that the filler content influences the foam morphology where a transition from closed to mixed and then closed cell again was observed with increasing filler content. Consequently, depending on the distribution and interconnection of the structural channels, a different effectiveness in guaranteeing mass diffusion phenomena was identified. In particular, permeability tests show that foams with 50 wt% of salt hydrates have a highly interconnected microstructure allowing a permeability over three times higher than a closed cell structure making it suitable for thermochemical energy storage applications.This work was partially funded by the Ministerio de Ciencia, Innovaci on y Universidades de España (MCIU/AEI/ FEDER, UE) (RTI2018-093849-B-C31) and by the Ministerio de Ciencia, Innovaci on y Universidades - Agencia Estatal de Investigaci on (AEI) (RED2018-102431-T). Dr. Luisa F. Cabeza would like to thank the Catalan Government for the quality accreditation given to her research group (2017 SGR 1537). GREiA is certified agent TECNIO in the category of technology developers from the Government of Catalonia. This work is partially supported by ICREA under the ICREA Academia program. Furthermore, special thanks to Dr. Angela Caprì who made the composite foam samples used for this experimental campaign. Open Access Funding provided by Universita degl

Alternative symplectic structures for SO(3,1) and SO(4) four-dimensional BF theories

The most general action, quadratic in the B fields as well as in the curvature F, having SO(3,1) or SO(4) as the internal gauge group for a four-dimensional BF theory is presented and its symplectic geometry is displayed. It is shown that the space of solutions to the equations of motion for the BF theory can be endowed with symplectic structures alternative to the usual one. The analysis also includes topological terms and cosmological constant. The implications of this fact for gravity are briefly discussed.Comment: 13 pages, LaTeX file, no figure

S_3-flavour symmetry as realized in lepton flavour violating processes

A variety of lepton flavour violating effects related to the recent discovery of neutrino oscillations and mixings is here systematically discussed in terms of an S_3-flavour permutational symmetry. After a brief review of some relevant results on lepton masses and mixings, that had been derived in the framework of a Minimal S_3-Invariant Extension of the Standard Model, we derive explicit analytical expressions for the matrices of the Yukawa couplings and compute the branching ratios of some selected flavour changing neutral current (FCNC) processes, as well as, the contribution of the exchange of neutral flavour changing scalars to the anomaly of the muon's magnetic moment as functions of the masses of the charged leptons and the neutral Higgs bosons. We find that the S_3 x Z_2 flavour symmetry and the strong mass hierarchy of the charged leptons strongly suppress the FCNC processes in the leptonic sector well below the present experimental upper bounds by many orders of magnitude. The contribution of FCNC to the anomaly of the muon's magnetic moment is small but non-negligible.Comment: 23 pages, one figure. To appear in J. Phys A: Mathematical and Theoretical (SPE QTS5

The breaking of the flavour permutational symmetry: Mass textures and the CKM matrix

Different ansaetze for the breaking of the flavour permutational symmetry according to S(3)L X S(3)R in S(2)L X S(2) give different Hermitian mass matrices of the same modified Fritzsch type, which differ in the symmetry breaking pattern. In this work we obtain a clear and precise indication on the preferred symmetry breaking scheme from a fit of the predicted theoretical Vckm to the experimentally determined absolute values of the elements of the CKM matrix. The preferred scheme leads to simple mass textures and allows us to compute the CKM mixing matrix, the Jarlskog invariant J, and the three inner angles of the unitarity triangle in terms of four quark mass ratios and only one free parameter: the CP violating phase Phi. Excellent agreement with the experimentally determined absolute values of the entries in the CKM matrix is obtained for Phi = 90 deg. The corresponding computed values of the Jarlskog invariant and the inner angles are J = 3.00 X 10^-5, alpha= 84 deg, beta= 24 deg and gamma =72 deg in very good agreement with current data on CP violation in the neutral kaon-antikaon system and oscillations in the B-Bbar system.Comment: 21 pages, 1 fig. Content enlarged, references added and typos corrected. To be published in Phys Rev

Rendimiento de terneros alimentados con silo de maíz o láctico con un promotor de la fermentación ruminal

Se efectuó el engorde de 120 bovinos (296 &plusmn; 6,9 kg) machos cruzados de Cebú durante 120 días divididos en tres tratamientos. Tratamiento 1: 40 animales alimentados con ensilaje normal de maíz (EN). Tratamiento 2: n= 40 animales alimentados con ensilaje inoculado con probiótico láctico enriquecido en N no proteico (NNP) (EP). Tratamiento 3 (EPS): 40 bovinos alimentados con EP más un suplemento nitrogenado de lento consumo (SNLC). Se emplearon tres toros canulados para estudiar la cinética ruminal y la digestibilidad in vivo. La concentración de NH3 en el fluido ruminal fue significativamente menor en EN (15 mg/100 ml) que en EP y EPS (18 y 22 mg/100 ml, respectivamente). La degradabilidad in situ de la FND fue 28% en EN, 38% para EP y 48% en EPS (p<0,05). El coeficiente de digestibilidad aparente de la MS fue significativamente menor en EN (57%) comparado con 68% en EP y 70% en EPS. El consumo voluntario fue menor (p<0,05) en EN (90 g/kg0,75/d) comparado con 120 y 140 g/kg0,75/d para EP y EPS respectivamente. Se observó un aumento en la ingestión de N de 72 g/d (EN) a 218 g/d (EP) y 277 g/d en EPS, aunque no se observan diferencias en la eficiencia de utilización entre los tratamientos EP y EPS. La digestibilidad aparente del N aumentó de un 73% para EN a un 76% para EP y EPS. Las cuentas de lactobacilos fueron de 1,6 millones/ml en EN, 10,5 en EP, a 12,5 millones/ml en el EPS. La excreción de derivados púricos aumentó en las dos dietas con el probiótico (p<0,05). Las ganancias diarias de peso fueron diferentes (p<0,05) para las 3 dietas (0,874 kg/d para EN, 1,172 para EP y 1,250 para EPS). La oferta de ensilaje de maíz enriquecido con probióticos con o sin suplemento nitrogenado de lento consumo incrementó la ganancia de peso en bovinos en engorde mejorando el proceso de fermentación ruminal e incrementando la producción de proteína microbiana