3,870 research outputs found
Superstable cycles for antiferromagnetic Q-state Potts and three-site interaction Ising models on recursive lattices
We consider the superstable cycles of the Q-state Potts (QSP) and the
three-site interaction antiferromagnetic Ising (TSAI) models on recursive
lattices. The rational mappings describing the models' statistical properties
are obtained via the recurrence relation technique. We provide analytical
solutions for the superstable cycles of the second order for both models. A
particular attention is devoted to the period three window. Here we present an
exact result for the third order superstable orbit for the QSP and a numerical
solution for the TSAI model. Additionally, we point out a non-trivial
connection between bifurcations and superstability: in some regions of
parameters a superstable cycle is not followed by a doubling bifurcation.
Furthermore, we use symbolic dynamics to understand the changes taking place at
points of superstability and to distinguish areas between two consecutive
superstable orbits.Comment: 12 pages, 5 figures. Updated version for publicatio
Performance of a C4F8O Gas Radiator Ring Imaging Cherenkov Detector Using Multi-anode Photomultiplier Tubes
We report on test results of a novel ring imaging Cherenkov (RICH) detection
system consisting of a 3 meter long gaseous C4F8O radiator, a focusing mirror,
and a photon detector array based on Hamamatsu multi-anode photomultiplier
tubes. This system was developed to identify charged particles in the momentum
range from 3-70 GeV/c for the BTeV experiment.Comment: 28 pages, 23 figures, submitted to Nuclear Instruments and Method
Model-Independent Determination of the Strong-Phase Difference Between D0 and D0 → K0S,L h+h- (h=π,K) and its Impact on the Measurement of the CKM angle γ/φ3
We report the first determination of the relative strong-phase difference between D^0 -\u3e K^0_S,L K^+ K^- and D^0-bar -\u3e K^0_S,L K^+ K^-. In addition, we present updated measurements of the relative strong-phase difference between D^0 -\u3e K^0_S,L pi^+ pi^- and D^0-bar -\u3e K^0_S,L pi^+ pi^-. Both measurements exploit the quantum coherence between a pair of D^0 and D^0-bar mesons produced from psi(3770) decays. The strong-phase differences measured are important for determining the Cabibbo-Kobayashi-Maskawa angle gamma/phi_3 in B^- -\u3e K^- D^0-tilde decays, where D^0-tilde is a D^0 or D^0-bar meson decaying to K^0_S h^+ h^- (h=pi,K), in a manner independent of the model assumed to describe the D^0 -\u3e K^0_S h^+ h^- decay. Using our results, the uncertainty in gamma/phi_3 due to the error on the strong-phase difference is expected to be between 1.7 and 3.9 degrees for an analysis using B^- K^- D^0-tilde D^0-tilde -\u3e K^0_S pi^+ pi^- decays, and between 3.2 and 3.9 degrees for an analysis based on B^- -\u3e K^- D^0-tilde, D^0-tilde -\u3e K^0_S K^+ K^- decays. A measurement is also presented of the CP-odd fraction, F_-, of the decay D^0 -\u3e K^0_S K^+ K^- in the region of the phi -\u3e K^+ K^- resonance. We find that in a region within 0.01 GeV^2/c^4 of the nominal phi mass squared F_- \u3e 0.91 at the 90% confidence level
The Cleo Rich Detector
We describe the design, construction and performance of a Ring Imaging
Cherenkov Detector (RICH) constructed to identify charged particles in the CLEO
experiment. Cherenkov radiation occurs in LiF crystals, both planar and ones
with a novel ``sawtooth''-shaped exit surface. Photons in the wavelength
interval 135--165 nm are detected using multi-wire chambers filled with a
mixture of methane gas and triethylamine vapor. Excellent pion/kaon separation
is demonstrated.Comment: 75 pages, 57 figures, (updated July 26, 2005 to reflect reviewers
comments), to be published in NIM
Model-Independent Determination of the Strong-Phase Difference Between D^0 and D^0-bar-\u3e K^0_S,L h^+ h^- (h=pi,K) and its Impact on the Measurement of the CKM angle gamma/phi_3
We report the first determination of the relative strong-phase difference between D^0 -\u3e K^0_S,L K^+ K^- and D^0-bar -\u3e K^0_S,L K^+ K^-. In addition, we present updated measurements of the relative strong-phase difference between D^0 -\u3e K^0_S,L pi^+ pi^- and D^0-bar -\u3e K^0_S,L pi^+ pi^-. Both measurements exploit the quantum coherence between a pair of D^0 and D^0-bar mesons produced from psi(3770) decays. The strong-phase differences measured are important for determining the Cabibbo-Kobayashi-Maskawa angle gamma/phi_3 in B^- -\u3e K^- D^0-tilde decays, where D^0-tilde is a D^0 or D^0-bar meson decaying to K^0_S h^+ h^- (h=pi,K), in a manner independent of the model assumed to describe the D^0 -\u3e K^0_S h^+ h^- decay. Using our results, the uncertainty in gamma/phi_3 due to the error on the strong-phase difference is expected to be between 1.7 and 3.9 degrees for an analysis using B^- K^- D^0-tilde D^0-tilde -\u3e K^0_S pi^+ pi^- decays, and between 3.2 and 3.9 degrees for an analysis based on B^- -\u3e K^- D^0-tilde, D^0-tilde -\u3e K^0_S K^+ K^- decays. A measurement is also presented of the CP-odd fraction, F_-, of the decay D^0 -\u3e K^0_S K^+ K^- in the region of the phi -\u3e K^+ K^- resonance. We find that in a region within 0.01 GeV^2/c^4 of the nominal phi mass squared F_- \u3e 0.91 at the 90% confidence level
Oseledets' Splitting of Standard-like Maps
For the class of differentiable maps of the plane and, in particular, for
standard-like maps (McMillan form), a simple relation is shown between the
directions of the local invariant manifolds of a generic point and its
contribution to the finite-time Lyapunov exponents (FTLE) of the associated
orbit. By computing also the point-wise curvature of the manifolds, we produce
a comparative study between local Lyapunov exponent, manifold's curvature and
splitting angle between stable/unstable manifolds. Interestingly, the analysis
of the Chirikov-Taylor standard map suggests that the positive contributions to
the FTLE average mostly come from points of the orbit where the structure of
the manifolds is locally hyperbolic: where the manifolds are flat and
transversal, the one-step exponent is predominantly positive and large; this
behaviour is intended in a purely statistical sense, since it exhibits large
deviations. Such phenomenon can be understood by analytic arguments which, as a
by-product, also suggest an explicit way to point-wise approximate the
splitting.Comment: 17 pages, 11 figure
Altered expression of cytokines in mice infected intranasally with two syncytial variants of Herpes simplex virus type 1
Immune evasion strategies are important for the onset and the maintenance of viral infections. Many viruses have evolved mechanisms to counteract or suppress the host immune response. We have previously characterized two syncytial (syn) variants of Herpes simplex 1 (HSV-1) strain F, syn14-1 and syn17-2, obtained by selective pressure with a natural carrageenan. These variants showed a differential pathology in vaginal and respiratory mucosa infection in comparison with parental strain. In this paper, we evaluated the modulation of immune response in respiratory mucosa by these HSV-1 variants. We observed altered levels of Tumor Necrosis Factor-α and Interleukin-6 in lungs of animals infected with the syn14-1 and syn17-2 variants compared with the parental strain. Also, we detected differences in the recruitment of immune cells to the lung in syn variants infected mice. Both variants exhibit one point mutation in the sequence of the gene of glycoprotein D detected in the ectodomain of syn14-1 and the cytoplasmic tail of syn17-2. Results obtained in the present study contribute to the characterization of HSV-1 syn variants and the participation of the cellular inflammatory response in viral pathogenesis.Fil: Artuso, MarĂa Carolina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de QuĂmica BiolĂłgica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de QuĂmica BiolĂłgica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Linero, Florencia Natalia. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de QuĂmica BiolĂłgica. Laboratorio de VirologĂa; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Gazzaniga, Silvina NoemĂ. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de QuĂmica BiolĂłgica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de QuĂmica BiolĂłgica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Scolaro, Luis Alberto. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de QuĂmica BiolĂłgica. Laboratorio de VirologĂa; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Pujol, Carlos Alberto. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de QuĂmica BiolĂłgica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de QuĂmica BiolĂłgica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Wainstok, Rosa. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de QuĂmica BiolĂłgica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de QuĂmica BiolĂłgica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Carlucci, Maria Josefina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de QuĂmica BiolĂłgica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de QuĂmica BiolĂłgica de la Facultad de Ciencias Exactas y Naturales; Argentin
Study of f_0(980) and f_0(1500) from B_s \to f_0(980)K, f_0(1500)K Decays
In this paper, we calculate the branching ratios and CP-violating asymmetries
for \bar B^0_s \to f_0(980)K, f_0(1500)K within Perturbative QCD approach based
on k_T factorization. If the mixing angle falls into the range of
25^\circ<\theta<40^\circ, the branching ratio of \bar B^0_s\to f_0(980)K is
2.0\times 10^{-6}<{\cal B}(\bar B^0_s\to f_0(980)K)<2.6\times 10^{-6}, while
lies in the range of 140^\circ<\theta<165^\circ, {\cal B}(\bar
B^0_s\to f_0(980)K) is about 6.5\times 10^{-7}. As to the decay {\cal B}(\bar
B^0_s\to f_0(1500)K), when the mixing scheme \mid f_0(1500)>=0.84\mid s\bar
s>-0.54\mid n\bar n> for f_0(1500) is used, it is difficult to determine which
scenario is more preferable than the other one from the branching ratios for
these two scenarios, because they are both close to 1.0\times10^{-6}. But there
exists large difference in the form factor F^{\bar B_s^0\to f_0(1500)} for two
scenarios.Comment: 14 pages, 3 figures, submitted to J. Phys.
An Update of Eyeglasses-Supported Nasal–Facial Prosthetic Rehabilitation of Cancer Patients with Post-Surgical Complications: A Case Report
Featured Application: This case report aims to describe an update of the digital protocol for the fabrication of a facial prosthesis for those patients who cannot be rehabilitated with plastic surgery because of post-surgical complications after maxillofacial surgery. In detail, it describes the application of the digital protocol to a mid-facial defect. The innovation proposed is oriented to simplify the procedures and reduce the time and cost of the process, aiming to recover the quality of life of inoperable patients. This case report aims to describe novel steps in the digital design/manufacturing of facial prostheses for cancer patients with wide inoperable residual defects, with a focus on a case of a mid-facial defect. A facial scanner was used to make an impression of the post-surgical residual defect and to digitalize it. The daughter’s face scan was used for reconstructing the missing anatomy. Using 3D printing technologies, try-in prototypes were produced in silicone material. The substructure was laser melted. The final prosthesis was relined directly onto the patient’s defect. The prosthesis resulted in a very low weight and a high elasticity of the external margins. The laser-melted substructure ensured the necessary rigidity with minimum thickness
Characterization and Modeling of Non-Uniform Charge Collection in CVD Diamond Pixel Detectors
A pixel detector with a CVD diamond sensor has been studied in a 180 GeV/c
pion beam. The charge collection properties of the diamond sensor were studied
as a function of the track position, which was measured with a silicon
microstrip telescope. Non-uniformities were observed on a length scale
comparable to the diamond crystallites size. In some regions of the sensor, the
charge drift appears to have a component parallel to the sensor surface (i.e.,
normal to the applied electric field) resulting in systematic residuals between
the track position and the hits position as large as 40 m. A numerical
simulation of the charge drift in polycrystalline diamond was developed to
compute the signal induced on the electrodes by the electrons and holes
released by the passing particles. The simulation takes into account the
crystallite structure, non-uniform trapping across the sensor, diffusion and
polarization effects. It is in qualitative agreement with the data. Additional
lateral electric field components result from the non-uniform trapping of
charges in the bulk. These provide a good explanation for the large residuals
observed.Comment: Accepted by Nucl. Instr. and Met
- …