New calculation schemes for proton-deuteron scattering including the Coulomb interaction

The Coulomb interaction between the protons is included in the description of proton-deuteron scattering using the screening and renormalization approach in the framework of momentum-space integral equations. Two new calculational schemes are presented that confirm the reliability of the perturbative approach for treating the screened Coulomb interaction in high partial waves, used by us in earlier works.Comment: To be published in Phys. Rev.

Electron trapping and acceleration by the plasma wakefield of a self-modulating proton beam

It is shown that co-linear injection of electrons or positrons into the wakefield of the self-modulating particle beam is possible and ensures high energy gain. The witness beam must co-propagate with the tail part of the driver, since the plasma wave phase velocity there can exceed the light velocity, which is necessary for efficient acceleration. If the witness beam is many wakefield periods long, then the trapped charge is limited by beam loading effects. The initial trapping is better for positrons, but at the acceleration stage a considerable fraction of positrons is lost from the wave. For efficient trapping of electrons, the plasma boundary must be sharp, with the density transition region shorter than several centimeters. Positrons are not susceptible to the initial plasma density gradient.Comment: 9 pages, 9 figures, 1 table, 44 reference

Benchmark calculation for proton-deuteron elastic scattering observables including Coulomb

Two independent calculations of proton-deuteron elastic scattering observables including Coulomb repulsion between the two protons are compared in the proton lab energy region between 3 MeV and 65 MeV. The hadron dynamics is based on the purely nucleonic charge-dependent AV18 potential. Calculations are done both in coordinate space and momentum space. The coordinate-space calculations are based on a variational solution of the three-body Schr\"odinger equation using a correlated hyperspherical expansion for the wave function. The momentum-space calculations proceed via the solution of the Alt-Grassberger-Sandhas equation using the screened Coulomb potential and the renormalization approach. Both methods agree within 1% on all observables, showing the reliability of both numerical techniques in that energy domain. At energies below three-body breakup threshold the coordinate-space method remains favored whereas at energies higher than 65 MeV the momentum-space approach seems to be more efficient.Comment: Submitted to Phys. Rev.

Riemann-Cartan Space-times of G\"odel Type

A class of Riemann-Cartan G\"odel-type space-times are examined in the light of the equivalence problem techniques. The conditions for local space-time homogeneity are derived, generalizing previous works on Riemannian G\"odel-type space-times. The equivalence of Riemann-Cartan G\"odel-type space-times of this class is studied. It is shown that they admit a five-dimensional group of affine-isometries and are characterized by three essential parameters $\ell, m^2, \omega$: identical triads ($\ell, m^2, \omega$) correspond to locally equivalent manifolds. The algebraic types of the irreducible parts of the curvature and torsion tensors are also presented.Comment: 24 pages, LaTeX fil

All-optical trapping and acceleration of heavy particles

A scheme for fast, compact, and controllable acceleration of heavy particles in vacuum is proposed, in which two counterpropagating lasers with variable frequencies drive a beat-wave structure with variable phase velocity, thus allowing for trapping and acceleration of heavy particles, such as ions or muons. Fine control over the energy distribution and the total charge of the beam is obtained via tuning of the frequency variation. The acceleration scheme is described with a one-dimensional theory, providing the general conditions for trapping and scaling laws for the relevant features of the particle beam. Two-dimensional, electromagnetic particle-in-cell simulations confirm the validity and the robustness of the physical mechanism.Comment: 10 pages, 3 figures, to appear in New Journal of Physic

Coherent photon assisted cotunneling in a Coulomb blockade device

We study cotunneling in a double junction Coulomb blockade device under the influence of time dependent potentials. It is shown that the ac-bias leads to photon assisted cotunneling which in some cases may dominate the transport. We derive a general non-perturbative expression for the tunneling current in the presence of oscillating potentials and give a perturbative expression for the photon assisted cotunneling current.Comment: Replaced with a longer paper which includes a non-perturbative calculation. 13 pages with 1 figure. To be published in Physical Review

Avaliação da formação de corpos lúteos acessórios e dosagem de progesterona em cabras da raça Saanen após o uso de hCG.

Avalia a formação de CLa e concentração plasmática de progesterona em decorrência da administração de hCG em cabras cinco dias após a última monta natural. Conclui-se que o tratamento com hCG 5 dias após a última MN induziu um efeito luteotrópico, e não a formação de CLa, antecipando o momento da ocorrência da elevação das concentração de progesterona plasmática. [Evaluation of formation of accessories corpora lutea and plasma progesterone concentration in Saanen goats treated with hCG]

Tillering Dynamics of \u3ci\u3ePanicum maximum\u3c/i\u3e Jacq. cv. Tanzania-1 After Grazing

Tillering dynamics and tiller dry matter weight from Tanzania grass (Panicum maximum cv. Tanzania-1) were evaluated in two post-grazing stubbles (High Post-grazing Stubble – HPS-3.6 t of DM/ha and Low Post-grazing Stubble – LPS-2.3 t of DM/ha). There was no difference between post-grazing stubbles for decapitated axillary and basal remainder and new axillary tillers. The LPS presented greater number of new basal tillers. The rate of appearance of new basal and axillary tillers decreased with time after grazing. There were differences between the treatments on tiller dry matter weight, and greater values were found in the high post-graze stubble

Avaliação do perfil fenotípico de caprinos brasileiros e africanos.

Resumo: Objetivou-se diferenciar populações caprinas brasileiras e cabo-verdianas (n=1084) por meio de descritores biométricos e comparação com raças comerciais. Foram avaliadas sete características de fêmeas adultas, através da estatística descritiva, análise de variância, teste de multicolinearidade, distância generalizada de Mahalanobis (D2) e algoritmo UPGMA. Após o teste de multicolinearidade foi identificada e descartada a variável profundidade torácica. O maior valor da D2 foi entre as populações Nambi e Mambrina (D2=93,78), e a menor D2 foi entre as cabras cabo-verdianas de Santo Antão e São Vicente (D2=0,41). O dendrograma colocou as raças Mambrina e Anglo-Nubiana a parte das demais. As cabras de Cabo Verde ficaram mais próximas das brasileiras de núcleos de conservação. As caboverdianas se agruparam segundo Barlavento e Sotavento. A eficácia da manutenção dos caprinos brasileiros em rebanhos de conservação nos faz preconizar tais iniciativas como ferramenta eficaz de manutenção dos recursos genéticos para potencial uso sustentável. Evaluation of the phenotypic profile of Brazilian and African goats. Abstract: The work aims was differentiate Brazilian goats populations of Cape Verdean (n = 1084) using biometric descriptors and comparison with commercial breeds. It was measured seven characteristics of female adult goats by using descriptive statistics, analysis of variance test multicollinearity, Mahalanobis distance (D2) and UPGMA algorithm. After testing of multicollinearity was identified and discarded the thoracic depth variable. The maximum value of D2 was between populations Nambi and Mambrina (D2 = 93.78), and the lower D2 was between the Cape Verdean goats of Santo Antão and São Vicente (D2 = 0.41). The dendrogram put the breeds Mambrina and Anglo-Nubian part of others. The goats of Cape Verde were closer to the Brazilian conservation nuclei. The Cape Verdean were made a group was Barlavento and Sotavento. The maintenance efficiency of the Brazilian goat herds conservation makes us valuate such initiatives as an effective tool for maintenance of genetic resources for potential use sustainable