The Bc→ψ(2S)πB_c\rightarrow \psi(2S)\pi, ηc(2S)π\eta_c(2S)\pi decays in the perturbative QCD approach

Nonleptonic two body $B_c$ decays including radially excited $\psi(2S)$ or $\eta_c(2S)$ mesons in the final state are studied using the perturbative QCD approach based on $k_T$ factorization. The charmonium distribution amplitudes are extracted from the $n = 2, l = 0$ Schr$\ddot{o}$dinger states for the harmonic oscillator potential. Utilizing these distribution amplitudes, we calculate the numerical results of the $B_c\rightarrow \psi(2S),\eta_c(2S)$ transition form factors and branching fractions of $B_c\rightarrow \psi(2S)\pi, \eta_c(2S)\pi$ decays. The ratio between two decay modes $B_c\rightarrow \psi(2S)\pi$ and $B_c\rightarrow J/\psi\pi$ is compatible with the experimental data within uncertainties, which indicate that the harmonic oscillator wave functions for $\psi(2S)$ and $\eta_c(2S)$ work well. It is found that the branching fraction of $B_c\rightarrow \eta_c(2S)\pi$, which is dominated by the twist-3 charmonium distribution amplitude, can reach the order of $10^{-3}$. We hope it can be measured soon in the LHCb experiment.Comment: 9 pages, 3 figures,3 Table

Estudio piloto de intervención de enfermería radiológica en examen de resonancia magnética 3-t

OBJETIVO Se objetivó investigar el efecto de la intervención de enfermería radiológica en examen abdominal de IRM 3-T. MÉTODO Sesenta pacientes con enfermedades abdominales fueron divididos aleatoriamente en dos grupos: grupo intervención de enfermería RM y grupo control. Todos fueron sometidos a examen abdominal de RM 3-T. Las intervenciones de enfermería RM se efectuaron en el grupo establecido. Los resultados, incluyendo tasa de éxito en única vez, relación de imágenes de RM diagnosticables y puntos de calidad de imagen, fueron comparadas entre ambos grupos. RESULTADOS La tasa de éxito en única vez en grupo control y grupo intervención de enfermería RM fueron de 66,67% y 96,67%, expresando diferencias significativas (χ2 =9.017, POBJETIVO O objetivo deste estudo foi investigar o resultado da intervenção de enfermagem na radiologia em exame de ressonância magnética (RM) abdominal 3 Tesla. MÉTODO 60 pacientes com patologias abdominais foram aleatoriamente divididos em dois grupos: grupo de intervenção de enfermagem em RM e grupo controle. Todos os pacientes foram submetidos ao exame de RM abdominal 3 Tesla. As intervenções de enfermagem em RM foram realizadas no grupo de intervenção de enfermagem. Os resultados foram comparados entre os dois grupos, incluindo a taxa de sucesso único, o coeficiente das imagens de RM diagnosticáveis e os pontos da qualidade de imagem. RESULTADOS As taxas de sucesso único no grupo controle e no grupo de intervenção de enfermagem em RM foram 66,67% e 96,67%, com diferença significativa de (χ2 =9,017, POBJECTIVE The aim of this study was to investigate the effect of radiology nursing intervention in abdominal examination at 3-T MRI. METHOD 60 patients with abdominal diseases were divided into two groups randomly: MR nursing intervention group and control group. All the patients underwent abdominal MR examination at 3-T. The MR nursing interventions were performed in nursing intervention group. The outcomes, including one-time success rate, the ratio of diagnosable MR images and the points of image quality, were compared between these two groups. RESULTS The one-time success rates in control group and MR nursing intervention group were 66.67% and 96.67% with significant difference ( χ2 =9.017,

A representation basis for the quantum integrable spin chain associated with the su(3) algebra

An orthogonal basis of the Hilbert space for the quantum spin chain associated with the su(3) algebra is introduced. Such kind of basis could be treated as a nested generalization of separation of variables (SoV) basis for high-rank quantum integrable models. It is found that all the monodromy-matrix elements acting on a basis vector take simple forms. With the help of the basis, we construct eigenstates of the su(3) inhomogeneous spin torus (the trigonometric su(3) spin chain with antiperiodic boundary condition) from its spectrum obtained via the off-diagonal Bethe Ansatz (ODBA). Based on small sites (i.e. N=2) check, it is conjectured that the homogeneous limit of the eigenstates exists, which gives rise to the corresponding eigenstates of the homogenous model.Comment: 24 pages, no figure, published versio

An hourglass model for the flare of HST-1 in M87

To explain the multi-wavelength light curves (from radio to X-ray) of HST-1 in the M87 jet, we propose an hourglass model that is a modified two-zone system of Tavecchio & Ghisellini (hereafter TG08): a slow hourglass-shaped or Laval nozzle-shaped layer connected by two revolving exponential surfaces surrounding a fast spine, through which plasma blobs flow. Based on the conservation of magnetic flux, the magnetic field changes along the axis of the hourglass. We adopt the result of TG08---the high-energy emission from GeV to TeV can be produced through inverse Compton by the two-zone system, and the photons from radio to X-ray are mainly radiated by the fast inner zone system. Here, we only discuss the light curves of the fast inner blob from radio to X-ray. When a compressible blob travels down the axis of the first bulb in the hourglass, because of magnetic flux conservation, its cross section experiences an adiabatic compression process, which results in particle acceleration and the brightening of HST-1. When the blob moves into the second bulb of the hourglass, because of magnetic flux conservation, the dimming of the knot occurs along with an adiabatic expansion of its cross section. A similar broken exponential function could fit the TeV peaks in M87, which may imply a correlation between the TeV flares of M87 and the light curves from radio to X-ray in HST-1. The Very Large Array (VLA) 22 GHz radio light curve of HST-1 verifies our prediction based on the model fit to the main peak of the VLA 15 GHz radio light curve.Comment: 14 pages, 2 figures, accepted for publication in A