Determination of the scattering length for Rb-Cs X1Σ+^{1}\Sigma ^{+} ground electronic state using a variational method

We performed the calculation of the scattering length for the elastic collision between the rubidium and cesium atoms. For this we applied a variational procedure based on the R-matrix theory for unbound states employing the finite element method (FEM) for expansion of the wave-function in terms of a finite set of local basis functions. The FEM presents as advantages the possibility of the development of a efficient matrix inversion algorithm which significantly reduces the computation time to calculate the R matrix. We also tested a potential energy curve with spectroscopic accuracy obtained before from a direct adjustment procedure of experimental data of the $X^{1}\Sigma^{+}$ state based on genetic algorithm. The quality of our result was evaluated by comparing them with several ones previously published at literature.Comment: 15 pages, 6 tables and 2 figure

^1S_0 pairing correlations in relativistic nuclear matter and the two-nucleon virtual state

We use the Gorkov formulation of the Dirac-Hartree-Fock-Bogoliubov approximation to nuclear pairing to study the ^1S_0 nucleon-nucleon correlations in nuclear matter. We find the short-range correlations of the ^1S_0 pairing fields to be almost identical to those of the two-nucleon virtual state. We obtain mutually consistent results for the pairing fields, using several different sets of effective interaction parameters, when we demand that each of these sets places the virtual-state pole at its physical location.Comment: 11 pages, 9 PostScript figures, RevTex, submitted to Phys. Rev.

Bounds on Z′Z^\prime from 3-3-1 model at the LHC energies

The Large Hadron Collider will restart with higher energy and luminosity in 2015. This achievement opens the possibility of discovering new phenomena hardly described by the Standard Model, that is based on two neutral gauge bosons: the photon and the $Z$. This perspective imposes a deep and systematic study of models that predicts the existence of new neutral gauge bosons. One of such models is based on the gauge group $SU(3)_C \times SU(3)_L \times U(1)_N$ called 3-3-1 model for short. In this paper we perform a study with $Z^\prime$ predicted in two versions of the 3-3-1 model and compare the signature of this resonance in each model version. By considering the present and future LHC energy regimes, we obtain some distributions and the total cross section for the process $p + p \longrightarrow \ell^{+} + \ell^{-} + X$. Additionally, we derive lower bounds on $Z^\prime$ mass from the latest LHC results. Finally we analyze the LHC potential for discovering this neutral gauge boson at 14 TeV center-of-mass energy.Comment: 6 pages, 9 figures, 2 table

Identification of the external branch of the superior laryngeal nerve during minimally invasive video-assisted thyroidectomy

The minimally invasive video-assisted thyroidectomy (MIVAT) without gas infusion is considered safe and has advantages in terms of cosmetic results compared to the conventional approach. AIM: to present our findings regarding the identification of the external branch of the superior laryngeal nerve (EBSLN) during MIVAT. STUDY DESIGN: Transversal cohort study. MATERIAL AND METHOD: twelve patients underwent hemithyroidectomy for thyroid nodular disease through MIVAT method. The upper pedicle of the thyroid was dissected under the magnified view at 0-degree five-millimeter endoscope in order to achieve the identification of EBSLN in all cases. RESULTS: We identified 10 (83.3%) EBSLN out of 12 cases. The nerve ran medially to the branches of the superior thyroid artery in 8 cases (80%) and crossed anteriorly in 2 (20%). CONCLUSIONS: We identified the EBSLN in 83.3% of the cases, whose course was medial to the branches of the superior thyroid artery in 80% and crossing anteriorly in 20%. The ligation of the upper pedicle of the thyroid can be performed under direct view of the EBSLN.A tireoidectomia minimamente invasiva vídeo-assistida (TIMIVA) sem infusão de gás é considerada segura com vantagem estética em relação ao procedimento convencional. OBJETIVO: Apresentar os achados de identificação do ramo externo do nervo laríngeo superior (RELS) durante a TIMIVA. FORMA DE ESTUDO: Estudo de coorte transversal. CASUÍSTICA E MÉTODO: Doze pacientes foram submetidos à hemitireoidectomia por doença nodular tireoidiana. Dissecamos o pedículo vascular tireoidiano superior com o auxílio de endoscópio de cinco milímetros de zero grau visando à identificação do RELS em todos os casos. RESULTADOS: Dos 12 casos, identificamos o RELS em 10 (83,3%), sendo que o trajeto era medial aos ramos da artéria tireoidiana superior em 8 (80%) e cruzava anteriormente tais ramos em 2 (20%). CONCLUSÕES: Identificamos o RELS em 83,3% dos casos, com trajeto medial aos ramos da artéria tireoidiana superior em 80% e cruzando anteriormente tais ramos em 20%. A ligadura do pedículo superior da tireóide pode ser feita com o RELS sob visão direta.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de MedicinaUniversidade Metropolitana de SantosUNIFESP, EPMSciEL

Cosmic String in Scalar-Tensor Gravity

The gravitational properties of a local cosmic string in the framework of scalar-tensor gravity are examined. We find the metric in the weak-field approximation and we show that, contrary to the General Relativity case, the cosmic string in scalar-tensor gravitation exerces a force on non-relativistic, neutral test particle. This force is proportional to the derivative of the conformal factor $A^{2}(\phi)$ and it is always attractive. Moreover, this force could have played an important role at the Early Universe, although nowadays it can be neglegible. It is also shown that the angular separation $\delta\varphi$ remains unaltered for scalar-tensor cosmic strings.Comment: 15 pages, LATEX, no figure