1,041 research outputs found

    Correlation functions in conformal Toda field theory I

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    Two-dimensional sl(n) quantum Toda field theory on a sphere is considered. This theory provides an important example of conformal field theory with higher spin symmetry. We derive the three-point correlation functions of the exponential fields if one of the three fields has a special form. In this case it is possible to write down and solve explicitly the differential equation for the four-point correlation function if the fourth field is completely degenerate. We give also expressions for the three-point correlation functions in the cases, when they can be expressed in terms of known functions. The semiclassical and minisuperspace approaches in the conformal Toda field theory are studied and the results coming from these approaches are compared with the proposed analytical expression for the three-point correlation function. We show, that in the framework of semiclassical and minisuperspace approaches general three-point correlation function can be reduced to the finite-dimensional integral.Comment: 54 pages, JHEP styl

    Lie and Noether symmetries of geodesic equations and collineations

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    The Lie symmetries of the geodesic equations in a Riemannian space are computed in terms of the special projective group and its degenerates (affine vectors, homothetic vector and Killing vectors) of the metric. The Noether symmetries of the same equations are given in terms of the homothetic and the Killing vectors of the metric. It is shown that the geodesic equations in a Riemannian space admit three linear first integrals and two quadratic first integrals. We apply the results in the case of Einstein spaces, the Schwarzschild spacetime and the Friedman Robertson Walker spacetime. In each case the Lie and the Noether symmetries are computed explicitly together with the corresponding linear and quadratic first integrals.Comment: 19 page

    Spatially and polarization resolved plasmon mediated transmission through continuous metal films

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    The experimental demonstration and characterization is made of the plasmon-mediated resonant transmission through an embedded undulated continuous thin metal film under normal incidence. 1D undulations are shown to enable a spatially resolved polarisation filtering whereas 2D undulations lead to spatially resolved, polarization independent transmission. Whereas the needed submicron microstructure lends itself in principle to CD-like low-cost mass replication by means of injection moulding and embossing, the present paper demonstrates the expected transmission effects on experimental models based on metal-coated photoresist gratings. The spectral and angular dependence in the neighbourhood of resonance are investigated and the question of the excess losses exhibited by surface plasmons is discusse

    Impurity state in the vortex core of d-wave superconductors: Anderson impurity model versus unitary impurity model

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    Using an extended Anderson/Kondo impurity model to describe the magnetic moments around an impurity doped in high-TcT_{\text{c}} d-wave cuprates and in the framework of the slave-boson meanfield approach, we study numerically the impurity state in the vortex core by exact diagonalization of the well-established Bogoliubov-de Gennes equations. The low-energy impurity state is found to be good agreement with scanning tunnelingmicroscopy observation. After pinning a vortex on the impurity site, we compare the unitary impurity model with the extended Anderson impurity model by examining the effect of the magnetic field on the impurity state. We find that the impurity resonance in the unitary impurity model is strongly suppressed by the vortex; while it is insensitive to the field in the extended Anderson impurity model.Comment: 8 pages, 3 figure

    Josephson Current in the Presence of a Precessing Spin

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    The Josephson current in the presence of a precessing spin between various types of superconductors is studied. It is shown that the Josephson current flowing between two spin-singlet pairing superconductors is not modulated by the precession of the spin. When both superconductors have equal-spin-triplet pairing state, the flowing Josephson current is modulated with twice of the Larmor frequency by the precessing spin. It was also found that up to the second tunneling matrix elements, no Josephson current can occur with only a direct exchange interaction between the localized spin and the conduction electrons, if the two superconductors have different spin-parity pairing states.Comment: 5 pages, 1 figur

    Study of the f2(1270)f_2(1270), f2(1525)f_2'(1525), f0(1370)f_0(1370) and f0(1710)f_0(1710) in the J/ψJ/\psi radiative decays

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    In this paper we present an approach to study the radiative decay modes of the J/ψJ/\psi into a photon and one of the tensor mesons f2(1270)f_2(1270), f2(1525)f'_2(1525), as well as the scalar ones f0(1370)f_0(1370) and f0(1710)f_0(1710). Especially we compare predictions that emerge from a scheme where the states appear dynamically in the solution of vector meson--vector meson scattering amplitudes to those from a (admittedly naive) quark model. We provide evidence that it might be possible to distinguish amongst the two scenarios, once improved data are available.Comment: The large Nc argument improved; version published in EPJA

    Excited B mesons from the lattice

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    We determine the energies of the excited states of a heavy-light meson QqˉQ\bar{q}, with a static heavy quark and light quark with mass approximately that of the strange quark from both quenched lattices and with dynamical fermions. We are able to explore the energies of orbital excitations up to L=3, the spin-orbit splitting up to L=2 and the first radial excitation. These bsˉb \bar{s} mesons will be very narrow if their mass is less than 5775 MeV -- the BKBK threshold. We investigate this in detail and present evidence that the scalar meson (L=1) will be very narrow and that as many as 6 bsˉb \bar{s} excited states will have energies close to the BKBK threshold and should also be relatively narrow.Comment: 17 pages, 6 ps figure

    Glenohumeral Hydrodistension for Postoperative Stiffness After Arthroscopic Primary Rotator Cuff Repair

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    Background: Postoperative stiffness is a known complication after rotator cuff repair (RCR). Glenohumeral hydrodistension (GH) has been a treatment modality for shoulder pathology but has not been used to treat postoperative stiffness after RCR. Purpose/Hypothesis: The purpose of this study was to identify the risk factors for postoperative stiffness after RCR and review outcomes after treatment with GH. Our hypotheses were that stiffness would be associated with diabetes and hyperlipidemia and correlated with the tendons involved and that patients with stiffness who underwent GH would have significant improvement in range of motion (ROM). Study Design: Case series; Level of evidence, 4.Methods:Included were 388 shoulders of patients who underwent primary RCR by a single surgeon between 2015 and 2019. Shoulders with revision RCRs were excluded. Patient characteristics, medical comorbidities, and perioperative details were collected. A total of 40 shoulders with postoperative stiffness (10.3%) received GH injectate of a 21-mL mixture (15 mL of sterile water, 5 mL of 0.5% ropivacaine, and 1 mL of triamcinolone [10 mg/mL]). The primary outcome measure was ROM in forward flexion, internal rotation, external rotation, and abduction. Statistical tests were performed using analysis of variance. Results: Patients with diabetes had significantly decreased internal rotation at final follow-up after RCR as compared with patients without diabetes. GH to treat stiffness was performed most commonly between 1 and 4 months after RCR (60%), and patients who received GH saw statistically significant improvements in forward flexion, external rotation, and abduction after the procedure. Patients with hyperlipidemia had the most benefit after GH. Among those undergoing concomitant procedures, significantly more patients who had open subpectoral biceps tenodesis underwent GH. Patients who underwent subscapularis repair or concomitant subacromial decompression had significant improvement in ROM after GH. Only 1 patient who received GH underwent secondary surgery for resistant postoperative stiffness. Conclusion: Patients with diabetes had increased stiffness. Patients with a history of hyperlipidemia or concomitant open subpectoral biceps tenodesis were more likely to undergo GH for postoperative stiffness. Patients who underwent subscapularis repair demonstrated the most improvement in ROM after GH. After primary RCR, GH can increase ROM and is a useful adjunct for patients with stiffness to limit secondary surgery
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