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Stephan Narison 《Physics letters. [Part B]》2013,718(4-5):1321-1333
Using recent values of the QCD (non-)perturbative parameters given in Table 1 and an estimate of the N3LO QCD perturbative contributions based on the geometric growth of the PT series, we re-use QCD spectral sum rules (QSSR) known to N2LO PT series and including all dimension-six NP condensate contributions in the full QCD theory, for improving the existing estimates of and from the open charm and beauty systems. We especially study the effects of the subtraction point on “different QSSR data” and use (for the first time) the Renormalization Group Invariant (RGI) scale-independent quark masses in the analysis. The estimates [rigourous model-independent upper bounds within the SVZ framework] reported in Table 8: , and , , which improve previous QSSR estimates, are in perfect agreement (in values and precisions) with some of the experimental data on and on recent lattice simulations within dynamical quarks. These remarkable agreements confirm both the success of the QSSR semi-approximate approach based on the OPE in terms of the quark and gluon condensates and of the Minimal Duality Ansatz (MDA) for parametrizing the hadronic spectral function which we have tested from the complete data of the and ? systems. The values of the running quark masses and from are in good agreement though less accurate than the ones from recent and ? sum rules. 相似文献
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《Nuclear Physics B》2006,732(3):444-462
In this paper we discuss representations of the Birman–Wenzl–Murakami algebra as well as of its dilute extension containing several free parameters. These representations are based on superalgebras and their baxterizations permit us to derive novel trigonometric solutions of the graded Yang–Baxter equation. In this way we obtain the multiparametric R-matrices associated to the , and quantum symmetries. Two other families of multiparametric R-matrices not predicted before within the context of quantum superalgebras are also presented. The latter systems are indeed non-trivial generalizations of the vertex model when both distinct edge variables statistics and extra free-parameters are admissible. 相似文献
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The structural and thermodynamic properties of titanium nitride (TiN) have been investigated by merging first-principles calculations and particle-swarm algorithm. The three phases are identified for TiN, including the B1, the , and the B2 phases. A new phase of anti-TiP structure with the space group has been predicted. The calculated phase transition from the B1 to the occurs at 270 GPa. The vibrational, elastic, and thermodynamic properties for the three phases have been calculated and discussed. 相似文献
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《Radiation measurements》2008,43(8):1325-1330
A new glow curve fitting function is proposed for mixed-order kinetics. The free parameters of this function are the glow curve maximum , the temperature maximum , activation energy and ratio , where and are initial concentrations of electrons in active and inactive traps, respectively. The new fitting method for determination of the thermoluminescence (TL) parameters is checked for some characteristics values of the parameters. The characteristics of this obtained function are simplicity, clearness and precision. To get this function only analytical terms obtained out of mixed-order kinetics equation were used. There are no empirical terms. 相似文献
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《Radiation measurements》2007,42(4-5):874-877
Ytterbium doped borate crystals are promising laser media, e.g. in (LSB) matrices large distance between ytterbium ions results in reduced concentration quenching of the ytterbium f–f luminescence [Petermann, K., Fagundes-Peters, D., Johansen, O., Mond, M., Peters, V., Romero, J.J., Kutovoi, S., Speiser, J., Giesen, A., 2005. Highly Yb-doped oxides for thin-disc lasers. J. Crystal Growth 275, 135-140]. ions in complex oxides in addition to the 4f 4f transitions often manifest fast charge transfer luminescence (CTL) in the UV-visible range. In some borates it was not observed at all, like in orthoborates of Sc, Y and La [Van Pieterson, L., Heeroma, M., de Heer, E., Meijerink, A., 2000. Charge transfer luminescence of . J. Lumin. 91, 177–193]; in haloborates , where X = Cl, Br, the UV/visible luminescence was attributed to ytterbium CTL though it looked substantially different from other matrices [Dotsenko, V.P., Berezovskaya, I.V., Pyrogenko, P.V., Efryushina, N.P., Rodniy, P.A., Eijk van, C.W.E., Sidorenko, A.V., 2002. Valence states and luminescence properties of ytterbium ions in strontium haloborates. J. Solid State Chem. 166, 271–276]; while in oxyborate “classical” CTL was observed [Jubera, V., Garcia, A., Chaminade, J.P., Guillen, F., Sablayrolles, Jean, Fouassier, C., 2007. and luminescent properties of the phase. J. Lumin. 124(1), 10–14]. In this work the luminescence properties of another borate, namely LSB doped by Yb are presented. 相似文献
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Luminescent, optical and color properties of natural rose quartz 总被引:2,自引:0,他引:2
R. Kibar J. Garcia-Guinea A. etin S. Selvi T. Karal N. Can 《Radiation measurements》2007,42(10):1610-1617
Rose quartz is an interesting mineral with numerous impurities that have been studied by scanning electron microscopy (SEM), X-ray fluorescence (XRF), X-ray diffraction (XRD), cathodoluminescence (CL), ion beam luminescence (IBL), radioluminescence (RL), thermoluminescence (TL) and optical absorption (OA). After HF etching, rose quartz from Oliva de Plasencia (Caceres, Spain) shows under SEM the presence of other silicate phases such as dumortierite . The OA spectrum of rose quartz suggests that these inclusions are the cause of coloration of rose quartz. The luminescence (CL, IBL, RL, TL) spectra behavior, at both room temperature and lower, confirms that the emission could be associated with Si–O strain structures, including non-bridging oxygen or silicon vacancy–hole centers; the observed emission could be associated with recombination of a hole trapped adjacent to a substitutional, charge-compensated aluminum alkali ion center; the emission could be associated with substitutional and the peak could be associated with point defects in sites. These results suggest that, while defect properties of rose quartz are not greatly dissimilar to those of purer forms of quartz and silica, further research seems necessary to determine criteria for the evolution of the newly-formed self-organized microstructures in the rose quartz lattice under irradiation. 相似文献
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In this note, we investigate the electromagnetic radiation emitted from a revolving point charge in a compact space. If the point charge is circulating with an angular frequency on the -plane at with boundary conditions, and , it emits radiation into the z-direction of . We find that the radiation shows discontinuities as a function of at which a new propagating mode with a different Fourier component appears. For a small radius limit , all the Fourier modes except the zero mode on -plane are killed, but an effect of squeezing the electric field totally enhances the radiation. In the large volume limit , the energy flux of the radiation reduces to the expected Larmor formula. 相似文献
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We have systematically investigated the disorder dependence electron phonon scattering rate in three dimensional disordered V82Pd18 ? xFex alloys. A minimum in temperature dependence resistivity curve has been observed at low temperature . In the temperature range the resistivity correction follows law. The dephasing scattering time has been calculated from analysis of magnetoresistivity by weak localization theory. The electron dephasing time is dominated by electron–phonon scattering and follows anomalous temperature (T) and disorder dependence behaviour like , where is the impurity resistivity. The magnitude of the saturated dephasing scattering time at zero temperature decreases with increasing disorder of the samples. Such anomalous behaviour of dephasing scattering rate is still unresolved. 相似文献