Electromagnetic Form Factors of a Massive Neutrino

Electromagnetic form factors of a massive neutrino are studied in a minimally extended standard model in an arbitrary $R_{\xi}$ gauge and taking into account the dependence on the masses of all interacting particles. The contribution from all Feynman diagrams to the charge, magnetic, and anapole form factors, in which the dependence on the masses of all particles as well as on gauge parameters is accounted for exactly, are obtained for the first time in explicit form. The asymptotic behavior of the magnetic form factor for large negative squares of the momentum of an external photon is analyzed and expression for the anapole moment of a massive neutrino is derived. The results are generalized to the case of mixing between various generations of the neutrino. Explicit expressions are obtained for the charge, magnetic, and electric dipole and anapole transition form factors as well as for the transition electric dipole moment.Comment: 16 pares with 5 figures in pdf forma

Oscillatons revisited

In this paper, we study some interesting properties of a spherically symmetric oscillating soliton star made of a real time-dependent scalar field which is called an oscillaton. The known final configuration of an oscillaton consists of a stationary stage in which the scalar field and the metric coefficients oscillate in time if the scalar potential is quadratic. The differential equations that arise in the simplest approximation, that of coherent scalar oscillations, are presented for a quadratic scalar potential. This allows us to take a closer look at the interesting properties of these oscillating objects. The leading terms of the solutions considering a quartic and a cosh scalar potentials are worked in the so called stationary limit procedure. This procedure reveals the form in which oscillatons and boson stars may be related and useful information about oscillatons is obtained from the known results of boson stars. Oscillatons could compete with boson stars as interesting astrophysical objects, since they would be predicted by scalar field dark matter models.Comment: 10 pages REVTeX, 10 eps figures. Updated files to match version published in Classical and Quantum Gravit

On the thermal footsteps of Neutralino relic gases

Current literature suggests that neutralinos are the dominant cold dark matter particle species. Assuming the microcanonical definition of entropy, we examine the local entropy per particle produced between the ``freeze out'' era to the present. An ``entropy consistency'' criterion emerges by comparing this entropy with the entropy per particle of actual galactic structures given in terms of dynamical halo variables. We apply this criterion to the cases when neutralinos are mosly b-inos and mostly higgsinos, in conjunction with the usual ``abundance'' criterion requiring that present neutralino relic density complies with 0.1 < \Omega_{\chic{\tilde\chi^0_1}} < 0.3 for $h\simeq 0.65$. The joint application of both criteria reveals that a better fitting occurs for the b-ino channels, hence the latter seem to be favoured over the higgsino channels. The suggested methodology can be applied to test other annihilation channels of the neutralino, as well as other particle candidates of thermal gases relics.Comment: LaTex AIP style, 8 pages including 1 figure. Final version to appear in Proceedings of the Mexican School of Astrophysics (EMA), Guanajuato, M\'exico, July 31 - August 7, 200

Can dark matter be a Bose-Einstein condensate?

We consider the possibility that the dark matter, which is required to explain the dynamics of the neutral hydrogen clouds at large distances from the galactic center, could be in the form of a Bose-Einstein condensate. To study the condensate we use the non-relativistic Gross-Pitaevskii equation. By introducing the Madelung representation of the wave function, we formulate the dynamics of the system in terms of the continuity equation and of the hydrodynamic Euler equations. Hence dark matter can be described as a non-relativistic, Newtonian Bose-Einstein gravitational condensate gas, whose density and pressure are related by a barotropic equation of state. In the case of a condensate with quartic non-linearity, the equation of state is polytropic with index $n=1$. To test the validity of the model we fit the Newtonian tangential velocity equation of the model with a sample of rotation curves of low surface brightness and dwarf galaxies, respectively. We find a very good agreement between the theoretical rotation curves and the observational data for the low surface brightness galaxies. The deflection of photons passing through the dark matter halos is also analyzed, and the bending angle of light is computed. The bending angle obtained for the Bose-Einstein condensate is larger than that predicted by standard general relativistic and dark matter models. Therefore the study of the light deflection by galaxies and the gravitational lensing could discriminate between the Bose-Einstein condensate dark matter model and other dark matter models.Comment: 20 pages, 7 figures, accepted for publication in JCAP, references adde

General massive one-loop off-shell three-point functions

In this work we compute the most general massive one-loop off-shell three-point vertex in D-dimensions, where the masses, external momenta, and exponents of propagators are arbitrary. This follows our previous paper in which we have calculated several new hypergeometric series representations for massless and massive (with equal masses) scalar one-loop three-point functions, in the negative dimensional approach.Comment: 16 pages, 2 figures, 4 table

Hydrodynamics of galactic dark matter

We consider simple hydrodynamical models of galactic dark matter in which the galactic halo is a self-gravitating and self-interacting gas that dominates the dynamics of the galaxy. Modeling this halo as a sphericaly symmetric and static perfect fluid satisfying the field equations of General Relativity, visible barionic matter can be treated as ``test particles'' in the geometry of this field. We show that the assumption of an empirical ``universal rotation curve'' that fits a wide variety of galaxies is compatible, under suitable approximations, with state variables characteristic of a non-relativistic Maxwell-Boltzmann gas that becomes an isothermal sphere in the Newtonian limit. Consistency criteria lead to a minimal bound for particle masses in the range $30 \hbox{eV} \leq m \leq 60 \hbox{eV}$ and to a constraint between the central temperature and the particles mass. The allowed mass range includes popular supersymmetric particle candidates, such as the neutralino, axino and gravitino, as well as lighter particles ($m\approx$ keV) proposed by numerical N-body simulations associated with self-interactive CDM and WDM structure formation theories.Comment: LaTeX article style, 16 pages including three figures. Final version to appear in Classical and Quantum Gravit

Intercropping of tomato with antagonistic plants in the treatment of soil infested with Meloidogyne spp., under greenhouse

El intercultivo de tomate con especies antagónicas se considera una alternativa de manejo de Meloidogyne spp. El objetivo del trabajo fue evaluar el intercultivo de las especies Tagetes erecta, Tagetes minuta y Crotalaria juncea para el manejo de Meloidogyne spp., en el cultivo de tomate. Se determinó, en las plantas de tomate, el índice de agallas y el número y peso de frutos. El intercultivo de tomate con T. erecta mostro un menor índice de agallas que el resto de los tratamientos evaluados. Además, se observó en este tratamiento, y en el de T. minuta, un mayor peso y número de frutos con respecto al tratamiento con C. juncea y al testigo sin intercultivo. En las condiciones de este ensayo, el intercultivo de tomate con T. erecta mostró ser una buena alternativa de manejo de Meloidoigyne spp. Se contribuye con esta práctica a una menor utilización de fitosanitarios, con el efecto positivo que trae aparejado para con el medio ambiente, y a la obtención de un producto hortícola de mayor inocuidad para el consumo.Tomato intercropping with antagonistic species is considered a management alternative for Meloidogyne spp. The objective of the work was to evaluate the intercropping of Tagetes erecta, Tagetes minuta and Crotalaria juncea for the management of Meloidogyne spp., in tomato cultivation. The gall index and the number and weight of fruits were determined in tomato plants. Tomato intercropping with T. erecta showed a lower gall index than the rest of evaluated treatments. In addition, a higher weight and number of fruits were observed in this treatment and in the one with T. minuta, respect to the C. juncea treatment and the control without intercropping. Under the conditions of this trial, intercropping of tomato with T. erecta proved to be a good alternative for the management of Meloidoigyne spp. This practice contributes to a lesser use of phytosanitary products, with the positive effect that it has on the environment, and to the obtaining of a more innocuous horticultural product for human consumption.Fil: Comezaña, María Micaela. Universidad Nacional del Sur. Departamento de Agronomía; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca; ArgentinaFil: Rodríguez, R. A.. Universidad Nacional del Sur. Departamento de Agronomía; ArgentinaFil: Ayastuy, M. E.. Universidad Nacional del Sur. Departamento de Agronomía; ArgentinaFil: Muscolino, C.. Universidad Nacional del Sur. Departamento de Agronomía; ArgentinaFil: Rosetti, F.. Universidad Nacional del Sur. Departamento de Agronomía; ArgentinaFil: Belladonna, D. P.. Universidad Nacional del Sur. Departamento de Agronomía; Argentin

Stability of the monoclinic phase in the ferroelectric perovskite PbZr(1-x)TixO3

Recent structural studies of ferroelectric PbZr(1-x)TixO3 (PZT) with x= 0.48, have revealed a new monoclinic phase in the vicinity of the morphotropic phase boundary (MPB), previously regarded as the the boundary separating the rhombohedral and tetragonal regions of the PZT phase diagram. In the present paper, the stability region of all three phases has been established from high resolution synchrotron x-ray powder diffraction measurements on a series of highly homogeneous samples with 0.42 <=x<= 0.52. At 20K the monoclinic phase is stable in the range 0.46 <=x<= 0.51, and this range narrows as the temperature is increased. A first-order phase transition from tetragonal to rhombohedral symmetry is observed only for x= 0.45. The MPB, therefore, corresponds not to the tetragonal-rhombohedral phase boundary, but instead to the boundary between the tetragonal and monoclinic phases for 0.46 <=x<= 0.51. This result provides important insight into the close relationship between the monoclinic phase and the striking piezoelectric properties of PZT; in particular, investigations of poled samples have shown that the monoclinic distortion is the origin of the unusually high piezoelectric response of PZT.Comment: REVTeX file, 7 figures embedde

Prevalence and management of pain in Italian patients with advanced non-small-cell lung cancer

Pain is a highly distressing symptom for patients with advanced cancer. WHO analgesic ladder is widely accepted as a guideline for its treatment. Our aim was to describe pain prevalence among patients diagnosed with advanced non-small-cell lung cancer (NSCLC), impact of pain on quality of life (QoL) and adequacy of pain management. Data of 1021 Italian patients enrolled in three randomised trials of chemotherapy for NSCLC were pooled. QoL was assessed by EORTC QLQ-C30 and LC-13. Analgesic consumption during the 3 weeks following QoL assessment was recorded. Adequacy of pain management was evaluated by the Pain Management Index (PMI). Some pain was reported by 74% of patients (42% mild, 24% moderate and 7% severe); 50% stated pain was affecting daily activities (30% a little, 16% quite a bit, 3% very much). Bone metastases strongly affected presence of pain. Mean global QoL linearly decreased from 64.9 to 36.4 from patients without pain to those with severe pain (P<0.001). According to PMI, 616 out of 752 patients reporting pain (82%) received inadequate analgesic treatment. Bone metastases were associated with improved adequacy and worst pain with reduced adequacy at multivariate analysis. In conclusion, pain is common in patients with advanced NSCLC, significantly affects QoL, and is frequently undertreated. We recommend that: (i). pain self-assessment should be part of oncological clinical practice; (ii). pain control should be a primary goal in clinical practice and in clinical trials; (iii). physicians should receive more training in pain management; (iv). analgesic treatment deserves greater attention in protocols of anticancer treatment

Assessment of Ergonomic Aspects in Dental Clinic Rooms

This study aimed to describe how to evaluate and quantify the ergonomic satisfaction level of dental clinics rooms. Requirements for design, production and selection of dental equipment as described in ISO/TC-106/SC-6-N-411, support more comprehensive studies for an ergonomic evaluation and ergo design of the dental workstations. It was created a checklist of ergonomics requirements which is supported by Standards ISO/FDI and acquired by mean of a literature review. According to information exposed at the document of the Ergonomics Society of Dental Ergonomics - ESDE we can consider that the elaboration of an ergonomic evaluation protocol regard to the dental workstation is an important demand for the ergonomics, particularly in relation to the performance of the ergonomic design which presents qualified to assist to dental equipment manufactures. By this means, the identification of the evaluation factors pointed in ISO/TC 106/SC 6 N 411 offers the basic information to the process of elaboration of this protocol addressed by the described general guidelines.4116103610