Top-quark-mass enhancement in a seesaw-type quark mass matrix

We investigate the implications of a seesawtype mass matrix, i.e.,M _f?m _LM _F ^?1 m _R, for quarks and leptonsf under the assumption that the matricesm _L andm _R are common to all flavors (up-/down- and quark-/lepton-sectors) and the matricesM _F characterizing the heavy fermion sectors have the form [(unit matrix)+b _f (a democratic matrix)] whereb _f is a flavor parameter. We find that by adjusting the complex parameterb _f, the model can provide thatm _t?m _b while at the same time keepingm _u～m _d without assuming any parameter with hierarchically different values betweenM _U andM _D. The model with three adjustable parameters under the “maximal” top-quark-mass enhancement can give reasonable values of five quark-mass ratios and four KM matrix parameters.     

Top-quark-mass enhancement in a seesaw-type quark mass matrix

We investigate the implications of a seesawtype mass matrix, i.e.,M _f?m _LM _F ^?1 m _R, for quarks and leptonsf under the assumption that the matricesm _L andm _R are common to all flavors (up-/down- and quark-/lepton-sectors) and the matricesM _F characterizing the heavy fermion sectors have the form [(unit matrix)+b _f (a democratic matrix)] whereb _f is a flavor parameter. We find that by adjusting the complex parameterb _f, the model can provide thatm _t?m _b while at the same time keepingm _u??m _d without assuming any parameter with hierarchically different values betweenM _U andM _D. The model with three adjustable parameters under the ??maximal?? top-quark-mass enhancement can give reasonable values of five quark-mass ratios and four KM matrix parameters.     

UV and VUV spectroscopic study of Na0.4Y0.6F2.2 crystals doped with rare-earth ions

The short-wavelength transmission spectra of Na_0.4 R _0.6F_2.2 crystals with R = Y, Yb, or Lu have been investigated. For these crystals, the VUV transmission cutoffs are 78750, 58820, and 75200 cm^?1, respectively. The 4f ⁿ–4f ^n?15d absorption and excitation spectra of Na_0.4Y_0.6F_2.2 crystals activated with Ce³⁺, Pr³⁺, Nd³⁺, Er³⁺, Tm³⁺, and Yb³⁺ ions have been analyzed in the range 30000–80000 cm^?1. The energy positions of the lowest levels of the 4f ^n?15d configurations of these ions in the fluorite crystal matrix Na_0.4Y_0.6F_2.2 are determined. The absorption band in the spectral range 60600–70000 cm^?1 in Na_0.4(Y, Yb)_0.6F_2.2 crystals is due to the charge transfer from F^? to Yb³⁺. It is shown that the environmental symmetry of Ce³⁺ ions in Na_0.4R_0.6F_2.2 (R = Y, Yb, Lu) crystals is almost identical.     

Fluorescence lifetimes and radiative rate constants of alkanes at 25°C

Fluorescence lifetimes of 33 alkanes were measured at 25°C using a 0.7 ns pulse radiolysis system and the relationship between molecular structure, fluorescence lifetime (τ), quantum yield (Φ_f) and radiative rate constant (R = $\text{Φ}{}_{\mathrm{f}}\text{τ}$) is discussed. The τ's showed a large dependence on the molecular structure, however, the R-values were approximately constant for groups of alkanes: R = 1.3×10⁶s^?1 for n-alkanes, R ≈ 4×10⁶ s^?1 for aliphatic vicinally substituted dimethyl alkanes, R = 7×10⁶s^-1 for cyclohexane and alkylcyclohexanes, and R = 10×10⁶s^?1 for di- and trimethylcyclohexanes. The excited state lifetimes of some non-fluorescing alkanes were also determined from steady-state photolytic quenching data and found to be very low (? 0.3 ns).     

Abstract concentratable and reducible linear functionals and generalized functions

In the class of linear mappings of the abstract (i.e., concretized by nothing) Poincaré invariant LIS (linear involutive space) L^a_f of test functions f:X∈R⁴ⁿ→f(X)∈C¹ into a LIS L and in the class of linear continuous mappings of the abstract Poincaré invariant locally convex topological LIS T^a_f into a locally convex topological LIS we axiomatize the notions of concentration of mappings in the closed sets δ?R⁴ⁿ and reductions of mappings to the Borel sets δ?R^4a. The axiomatization is necessary both for constructing abstract axiomatic quantum field theory and for consistent introduction of the above notions in concrete classes of generalized functions whose test function spaces contain no nontrivial finite function.     

Bianchi Type-II String Cosmological Model with Magnetic Field in f (R,T) Gravity

The spatially homogeneous and totally anisotropic Bianchi type-II cosmological solutions of massive strings have been investigated in the presence of the magnetic field in the framework of f(R,T) gravity proposed by Harko et al. (Phys Rev D 84:024020, 2011). With the help of special law of variation for Hubble^’s parameter proposed by Berman (Nuovo Cimento B 74:182, 1983) cosmological model is obtained in this theory. We consider f(R,T) model and investigate the modification R+f(T) in Bianchi type-II cosmology with an appropriate choice of a function f(T)=μ T. We use the power law relation between average Hubble parameter H and average scale factor R to find the solution. The assumption of constant deceleration parameter leads to two models of universe, i.e. power law model and exponential model. Some physical and kinematical properties of the model are also discussed.     

Bianchi Type-V Cosmology in f(R,T) Gravity with Λ(T)

A new class of cosmological models in f(R,T) modified theories of gravity proposed by Harko et al. (Phys. Rev. D 84:024020, 2011), where the gravitational Lagrangian is given by an arbitrary function of Ricci scalar R and the trace of the stress-energy tensor T, have been investigated for a specific choice of f(R,T)=f ₁(R)+f ₂(T) by considering time dependent deceleration parameter. The concept of time dependent deceleration parameter (DP) with some proper assumptions yield the average scale factor $a(t) = \sinh^{\frac{1}{n}}(\alpha t)$ , where n and α are positive constants. For 0<n≤1, this generates a class of accelerating models while for n>1, the models of universe exhibit phase transition from early decelerating phase to present accelerating phase which is in good agreement with the results from recent astrophysical observations. Our intention is to reconstruct f(R,T) models inspired by this special law for the deceleration parameter in connection with the theories of modified gravity. In the present study we consider the cosmological constant Λ as a function of the trace of the stress energy-momentum-tensor, and dub such a model “Λ(T) gravity” where we have specified a certain form of Λ(T). Such models may display better uniformity with the cosmological observations. The statefinder diagnostic pair {r,s} parameter has been embraced to characterize different phases of the universe. We also discuss the physical consequences of the derived models.     

On universality for area-preserving maps of the plane

We present detailed evidence that one-parameter families of area-preserving maps exhibit cascades of period doubling with universal geometric scaling in the parameter. We relate this behaviour to a fixed point equation of the form

$\text{Λ}{}^{\mathrm{?1}}\text{°Φ°Φ°Λ = Φ}$

and

$\text{det}\text{DΦ = 1}$

, Φ:$\text{R}$²→$\text{R}$². In particular we argue that the scaling transformation Λ:$\text{R}$²→$\text{R}$² is conjugate to the transformation Λ₀:(x, y)→(λx, μy), with λ² ≠ μ, and in fact λ² >μ. We present some numerical evidence that

$\text{δ = 8.721}$

…,

$\text{?}\text{1}\text{λ}\text{= 4.018}$

…,

$\text{1}\text{μ}\text{= 16.36}$

…, where δ is the asymptotic ratio of the differences of the parameter values corresponding to the successive periods 2^k described above.     

Superconductivity in thin tin films: Fluctuation effects

The excess electrical conductivity in thin tin films due to thermodynamic fluctuations above T_c has been measured as a function of temperature and sheet resistance R_ns of films which varied from 0.2 Ω/? to 120 Ω/?. Results have been compared with the Aslamazov-Larkin, Maki-Thompson and Patton theories. It is found that among three the Maki-Thompson theory gives a better fit to experimental data. The pair breaking parameter a fitting parameter in the M-T theory, is found to behave linearly with R_ns of films and is given by ? ? 9x10^?3 + 1.02x10^?2R_ns for R_ns ≤ 12 Ω/?.     

Thermoelectric properties of layered ferrocuprates <Emphasis Type="Italic">Ln</Emphasis>BaCuFeO<Subscript>5 + δ</Subscript> (<Emphasis Type="Italic">Ln</Emphasis>= La,Pr, Nd,Sm, Gd-Lu)

The electrical resistivity ρ and the thermopower S of ceramic materials LnBaCuFeO_{5 + δ} (Ln= La, Pr, Nd, Sm, Gd-Lu) are measured in air at temperatures in the range from 300 to 1100 K. All the studied ferrocuprates are p-type semiconductors. The electrical resistivity ρ and the thermopower S of these compounds increase with a decrease in the radius of the Ln ³⁺ cation (with an increase in the number of 4f electrons n in Ln ³⁺). The nonmonotonic behavior of the dependences ρ=f(n) and S=f(n) indicates that the electrical properties of the layered ferrocuprates LnBaCuFeO_{5 + δ} depend on the electronic configuration of the Ln ³⁺ cation. The power factors P calculated for the LnBaCuFeO_{5 + δ} ceramic materials from the experimental values of ρ and S increase with increasing temperature and, at T = 1000 K, reach the maximum values P = 102.0 and 54.1 µW m^?1 K^?2 for Ln = Pr(4f ²) and Sm(4f ⁵), respectively, and become close to each other and equal to 30–35 µW m^?1 K^?2 for Ln = Gd(4f ⁷), Dy(4f ⁹), and Ho(4f ¹⁰).     

Effect of A-site cation radius on thermodynamic properties of ARuO3 (A = Ca, Sr, and Ba)

The thermodynamic properties of alkaline earth ruthenate ARuO₃ (A?=?Ca, Sr, and Ba) perovskites have been investigated for the first time by means of a modified rigid ion model at temperature 1 K?≤?T?≤?300 K. As strong electron–phonon interactions are present in these compounds, the lattice contribution to the specific heat deserves proper attention. The values of specific heat calculated by us have shown remarkably good agreement with corresponding experimental data. We have found that in ARuO₃ (A?=?Ca, Sr, and Ba) ruthenate family, Debye temperature increases inversely with the ionic radius of the alkaline earth A cations. In addition, the results on the temperature dependence of thermal expansion coefficient (α), cohesive energy (?), molecular force constant (f), Reststrahlen frequency (υ), Debye temperature (θ _D), and Grüneisen parameter (γ) are also reported.     

Spectra of nonlocally bound quantum systems

We discuss a class of nonlinear and nonlocal models for the dynamics of a composite quantum system. The models in question depend on the following constituents: on two subsystem Hamiltonians (denoted by H and ?), an analytic function (f), and a real parameter (s). As demonstrated elsewhere before, the stationary states can be described in these models fairly explicitly. In this article, we build upon that result, and discuss the topological as well as statistical characteristics of the spectra. Here, we concentrate on the special case f = log. It turns out that an energy spectrum of the nonlocally bound system substantially differs from that of its components. Indeed, we show rigorously that, if H is the harmonic oscillator and ? is completely degenerate with one energy level, then the energy spectrum of the composite system has the topology of the Cantor set (for s > 2). In addition, we show that, if H is replaced by the logarithm of the harmonic oscillator, then the spectrum consists of finitely many intervals separated by gaps (for s sufficiently large). In the last case, the key analytic object is the series Σn ^?s . In particular, as an interesting offshoot, this structure furnishes a nontautological immersion of fundamental number-theoretic functions into the quantum formalism.     

Bonding and composition diagrams for sputtered a-Si : H

The combined influence of H partial pressure (p_H) and deposition rate (R_D) on Si-H bonding and total H content in diode-sputtered a-Si : H is presented in two simple graphs for the case of substrate temperature (T_s) equal to 225°C. Similar to a phase diagram, the graphs predict the H content and Si-H bonding that will result if a deposition is carried out with any prescribed pair of values (p_H, R_D), where 0.04 < p_H < 10 Paand 0.01 < R_D < 1 nm/sec. Well defined regions of Si-H bonding represented by dominant infrared stretching absorptions at 2000, 2090 and 2150 cm^?1 are obvious in the bonding diagram. The absorption at 2090 cm^?1 is the most commonly observed and is obtainable over a wide range of intermediate values of p_H and R_D. The absorption at 2000 cm^?1 is dominant only for the lowest p_H and the highest R_D. The absorption at 2150 cm^?1 is dominant in films deposited at high p_H and low R_D. The composition diagram shows that highest total H content is obtained for low R_D and high p_H, and lowest total H content results for high R_D and low p_H     

Bianchi type-I cosmology in f(R,T) gravity

We investigate the exact solutions of a Bianchi type-I space-time in the context of f(R, T) gravity [1], where f(R, T) is an arbitrary function of the Ricci scalar R and the trace of the energy-momentum tensor T. For this purpose, we find two exact solutions using the assumption of a constant deceleration parameter and the variation law of the Hubble parameter. The obtained solutions correspond to two different models of the Universe. The physical behavior of these models is also discussed.     

Large-scale structure of isotropic homogeneous turbulence

It is shown that the longitudinal correlation functionf is asymptotically proportional tor ^?3 asr→∞ and the energy spectrum function is asymptotically proportional toκ ² asκ→0 if and only if 0<〈(f u d ³ x)·u〉<∞. Moreover, the latter finiteness condition is shown to be essentially equivalent to 〈(fy·ud ³ x)²〉<∞ for nonstochasticyεL ²(R₃). Confirmed by recent experimental measurements, the larger dependencef ∝r ^?3 is concomitant with anO(r ^?6)=O(f ²) fall-off of the viscous force term in the Kármán-Howarth equation.     

Propagation of Hermite-cosh-Gaussian laser beams in n-InSb

The propagation of Hermite-cosh-Gaussian (HChG) laser beams in n-InSb are investigated for 0, 1 and 2 mode indices. The field distribution in the medium is expressed in terms of beam-width parameter f and decentred parameter b. The differential equations for f-parameter are established by parabolic wave equation approach under paraxial approximation. Analytical solutions are obtained under the condition R_n < R_d, where, R_n is the self-focusing length and R_d is the diffraction length. The behaviour of f-parameter with the dimensionless distance of propagation η for various b values is examined by numerical estimates. The results are presented graphically.     

Hard bremsstrahlung amplitudes fore + e − collisions with polarized beams at LEP/SLC energies

Cross sections are presented for the processese ⁺ e ^?→e ⁺ e ^?γ ande ⁺ e ^?→f \(\bar f\) γ (wheref is any light fermion) in the form of helicity amplitudes in which all complex phase information is kept. Owing to a spcial choice of the bremsstrahlung polarization and the use of spinor techniques the resultant expressions are extremely compact and lend themselves to fast numerical evaluation. An algorithm is given to obtain from the helicity amplitudes the cross section for arbitrary polarization of the incominge ⁺ e ^? beams. Special attention is given to the case of bremsstrahlung at very small angles to the beams, where a complicated dependence on the electron mass has to be taken into account.     

Constraints on the properties of the massive neutron star PSR J0348+0432 from the f0(975) and φ(1020) mesons

The effect of the f ₀(975) and φ(1020) mesons on the properties of the massive neutron star PSR J0348+0432 is examined in the framework of the relativistic mean-field theory by choosing the suitable hyperon coupling constants. It is found that, compared with that without the f ₀(975) and φ(1020) mesons, the radius of the neutron star PSR J0348+0432 increases from R = 12.072 km to R = 12.08 km (i.e. by 0.07%), the central energy density ? _c decreases from 5.6695 fm^?4 to 5.6492 fm^?4 (i.e. by 0.36%), the central pressure decreases from 1.585 fm^?4 to 1.58 fm^?4 (i.e. by 0.32%), the moment of inertia increases from 1.4592 × 10⁴⁵ g · cm² to 1.4615 × 10⁴⁵ g · cm² (i.e. by 0.16%) and the surface gravitational redshift decreases from z = 0.4026 to z = 0.4022 (i.e. by 0.1%). Our results show that the effect of the f ₀(975) and φ(1020) mesons on the properties of the massive neutron star PSR J0348+0432 is very small (i.e. no more than 0.5%) and therefore they do not play a major role.