ρ meson decays of heavy hybrid mesons

We calculate the ρ meson couplings between the heavy hybrid doublets H~h/S~h/M~h/T~h and the ordinary qQˉ doublets in the framework of the light-cone QCD sum rule. The sum rules obtained rely mildly on the Borel parameters in their working regions. The resulting coupling constants are rather small in most cases.     

θ dependence of QCD at finite isospin density

We probe the θ   dependence of QCD at finite isospin chemical potential μI${\mu }_I$ using the effective chiral Lagrangian approach. The phase diagram in the θ  , μI${\mu }_I$ plane is constructed and described in detail in terms of chiral and pion condensates. The physics at θ∼π$\theta \sim \pi$ is investigated in both the normal and superfluid phase. Finally, the behaviour of the gluon condensate at finite μI${\mu }_I$ is computed.     

Application of the vector ε and ρ extrapolation methods in the acceleration of the Richardson-Lucy algorithm

The vector ε and ρ extrapolation methods are applied in accelerating the convergence of the Richardson-Lucy (R-L) algorithm and its damped version. The theory and implementation are discussed in detail, and relevant numerical results are given, including the cases of noise-free images and images corrupted by the Poisson noise. The results show that the vector ε and ρ extrapolations of 9 orders can speed the convergence quite efficiently, and the ρ(9) method is more powerful than the ε(9) method for noisy degraded images. The extra computation burden due to the extrapolation is limited, and is well paid back by the accelerated convergence. The performances of these two methods are compared with the famous automatic acceleration method. For noise-free degraded images, the vector ε(9) and ρ(9) methods are more stable than the automatic method. For noisy degraded images, the damped R-L algorithm accelerated by vector ρ(9) or automatic methods is more powerful, and the instability of the automatic method is restrained by the damping strategy. We explain the instability of the method in accelerating the normal R-L algorithm by the numerical noise due to its frequent applications in the run.     

Doubly heavy baryon production at γγ collider

The inclusive production of doubly heavy baryons Ξ_cc${\Xi }_{cc}$ and Ξ_bb${\Xi }_{bb}$ at γγ collider is investigated. It is found that the contribution from the heavy quark pair QQ in color triplet and color sextet are important.     

Measurement of the branching ratios for the decays J/ψ → ϱπ and J/ψ → γη′

Decays of the J/ψ (3.1) resonance into final states with two charged hadrons and two photons are investigated. Branching ratios for the decays J/ψ → ?π and J/ψ → γη′ are determined to be

$\text{Г(J/ψ → pφ)}\text{Г(J/ψ → all)}\text{= (1.0± 0.2) ·10}{}^{\mathrm{?2}}\text{,}\text{Г(J/ψ → γη′)}\text{ГJ/ψ → all)}\text{= (2.0± 0.7) ·}{}^{\mathrm{?3}}$

Upper limits for the same decay modes of ψ′ (3.7) are also determined.     

Full lattice QCD study of the κ scalar meson

We studied the κ light scalar meson in 2+1 flavor full QCD with sufficiently light u and d quarks. Via lattice simulation we measured the correlators for the κ channel in the “Asqtad” improved staggered fermion formulation. After chiral extrapolation we obtained the mass of the κ meson with 826±119 MeV, which is within recent experimental values of 800-900 MeV. The simulations were carried out with the MILC 2+1 flavor gauge configurations at lattice spacing a ≈ 0.15 fm.     

Pair production of the heavy leptons associated with a gauge boson γ or Z at the ILC

The T-odd leptons are the typical particles predicted by the littlest Higgs model with T-parity (LHT model) and the observation of these particles might be regarded as the direct evidence of the LHT model. In this paper, we investigate the production of a pair of T-odd leptons associated with a gauge boson V (γ or Z  ) at the international linear e⁺e⁻$e^{+}{e}^{-}$ collider (ILC). The numerical results show that the possible signals of the T-odd leptons may be detected in the future ILC experiments.     

Quadripartite entanglement from cascaded χ nonlinear interactions

We theoretically analyze the generation of quadripartite continuous-variable entanglement, with different frequency, by cascaded nonlinear process in a quadruply resonant optical cavity. This process is realized by one optical parametric down-conversion operated below threshold cascaded by two sum-frequency generations in a quasiperiodic optical supperlattice. It shows that the signal, idler and two sum frequency modes are entangled according to the sufficient inseparability criterion proposed by van Loock and Furusawa. The quantum correlation spectra among these four modes versus normalized analysis frequency and nonlinear coupling coefficients are discussed as well in detail.     

Photonic band structure and effect of ε and μ on the reflectivity of one-dimensional magnetic photonic crystal structure

In this paper, we study the photonic band structure and reflection properties in one-dimensional magnetic photonic crystals (MPCs). Investigation of dispersion characteristics shows that in the case of MPCs, photonic band gaps arise due to the contrast in the wave impedance, not due to the contrast in the refractive index, while contrast in the refractive index of the two layers decides the position and number of the band gaps. We also study the effect of permittivity and permeability on reflection bands, which shows that the structure that has larger values of magnetic permeability (μ) than dielectric permittivity (ε) have wider TM-reflection bands, whereas the structure for which ε is greater than μ has wider TE-reflection bands. But the gap to mid-gap frequency ratio for TM-reflection bands is larger than TE-reflection bands. Thus, magnetic permeability has greater impact on the reflectivity of MPCs than dielectric permittivity. Finally, the analysis of the omni-reflectance in MPCs has also been studied.     

A deformed relativity with the quantum ℏ

Quantum relativity as a generalized, or rather deformed, version of Einstein relativity may offer a new framework to think about the structure of space–time at the true microscopic/quantum level. The approach typically gives some picture of a noncommutative (quantum) space–time. We propose a formulation with two deformations implemented on the Poincaré symmetry, using the independent Planck mass and Planck length as the invariant constraints. Together, they give the quantum ?  . The scheme leads to SO(2,4)$\mathit{SO}(2,4)$ as the relativity symmetry. We present a linear realization on a classical six-geometry beyond the familiar setting of space–time. Two extra coordinates to be considered as neither space nor time are needed. The last deformation step implementing the Planck length invariant constraines the six-geometry, as an extension of 4D space–time, giving it the structure of a AdS hypersurface. The resulted quantum world hence does not admit coordinate translation symmetries, which terminates further extension to an unstable symmetry. The quantum world is shown to be parallel to the “conformal universe”, but not scale invariant.     

μ–τ symmetry in Zee–Babu model

We study the Zee–Babu two-loop neutrino mass generation model and look for a possible flavor symmetry behind the tri-bimaximal neutrino mixing. We find that there probably exists the μ–τ   symmetry in the case of the normal neutrino mass hierarchy, whereas there may not be in the inverted hierarchy case. We also propose a specific model based on a Froggatt–Nielsen-like Z₅$Z_5$ symmetry to naturally accomplish the μ–τ symmetry on the neutrino mass matrix for the normal hierarchy case.     

Effects of orbital occupancies on the neutrinoless ββ matrix element of Ge

In this work we use the recently measured neutron occupancies in the ⁷⁶Ge and ⁷⁶Se nuclei as a guideline to define the neutron quasiparticle states in the 1p0f0g shell. We define the proton quasiparticles by inspecting the odd-mass nuclei adjacent to ⁷⁶Ge and ⁷⁶Se. We insert the resulting quasiparticles in a proton–neutron quasiparticle random-phase approximation (pnQRPA) calculation of the nuclear matrix element of the neutrinoless double beta (0νββ$0\nu \beta \beta$) decay of ⁷⁶Ge. A realistic model space and effective microscopic two-nucleon interactions are used. We include the nucleon–nucleon short-range correlations and other relevant corrections at the nucleon level. It is found that the resulting 0νββ$0\nu \beta \beta$ matrix element is smaller than in the previous pnQRPA calculations, and closer to the recently reported shell-model results.     

Three loop QCD MOM β-functions

We present the full expressions for the QCD β  -function in the MOMggg, MOMq and MOMh renormalization schemes at three loops for an arbitrary colour group in the Landau gauge. The results for all three schemes are in very good agreement with the SU(3)$\mathit{SU}(3)$ numerical estimates provided by Chetyrkin and Seidensticker.     

Relative merit of χ and χ SHG by charged water microdroplets - Implications for LIDAR

We investigated second harmonic generation (SHG) from neutral and electrically charged water microdroplets of uniform size. We found that angular distribution, polarization, and conversion efficiency of the SHG emission did not change within applied surface charge densities from 0 to 7.2 × 10⁻⁵ C/m². The latter is consistent with previously observed charge sensitive SHG efficiency on water interfaces if one considers particular experimental conditions. A brief discussion of the applicability of SHG for optical detection of charges in atmospheric clouds is given.     

Shell Model description of the ββ decay of Xe

We study in this Letter the double beta decay of ¹³⁶Xe with emission of two neutrinos which has been recently measured by the EXO-200 Collaboration. We use the same shell model framework, valence space, and effective interaction that we have already employed in our calculation of the nuclear matrix element (NME) of its neutrinoless double beta decay. Using the quenching factor of the Gamow–Teller operator which is needed to reproduce the very recent high resolution ¹³⁶Xe (³He, t) ¹³⁶Cs data, we obtain a nuclear matrix element M^2ν=0.025 MeV⁻¹${\mathrm{M}}^{2\nu }=0.025{\text{MeV}}^{-1}$ compared with the experimental value M^2ν=0.019(2) MeV⁻¹${\mathrm{M}}^{2\nu }=0.019(2){\text{MeV}}^{-1}$.     

First search for double β decay of dysprosium

A search for double β decay of dysprosium was realized for the first time with the help of an ultra-low background HP Ge γ detector. After 2512 h of data taking with a 322 g sample of dysprosium oxide limits on double beta processes in ¹⁵⁶Dy and ¹⁵⁸Dy have been established on the level of T_1/2?¹⁰¹⁴–¹⁰¹⁶ yr$T_{1/2}?{10}^{14}\text{–}{10}^{16}\text{yr}$. Possible resonant double electron captures in ¹⁵⁶Dy and ¹⁵⁸Dy were restricted on a similar level. As a by-product of the experiment we have measured the radioactive contamination of the Dy₂O₃ sample and set limits on the α   decay of dysprosium isotopes to the excited levels of daughter nuclei as T_1/2?¹⁰¹⁵–¹⁰¹⁷ yr$T_{1/2}?{10}^{15}\text{–}{10}^{17}\text{yr}$.     

Structural and superconductivity study on α-FeSex

We have successfully synthesized the α-FeSe_x binary tetragonal superconductors with nominal composition of FeSe_x (x=0.6-1.0) via conventional solid state reactions between Fe and Se sealed in quartz tubes. Fe and β-FeSe are the most commonly seen impurities in this binary system. A low-temperature annealing at 400 °C is found to be crucial to remove β-FeSe, which is the thermodynamic stable phase with hexagonal symmetry. For all the samples of FeSe_x, superconductivity is confirmed by magnetic measurements as well as resistivity measurements with their T_c at around 8 K. We noticed that their T_c does not vary with the different nominal Se amount. High-resolution synchrotron X-ray diffraction analysis revealed that the unit cell parameters of all these samples do not change within the error range, and their structure only tolerate the same very small amount of Se deficiency. Based on this study, we concluded that the α-FeSe_x superconductor only exist in a very narrow deficiency range.