Mixing among light scalar mesons and L=1 q\bar{q} scalar mesons

Following the re-establishment of the \sigma(600) and the \kappa(900), the light scalar mesons a_0(980) and f_0(980) together with the \sigma(600) and the \kappa(900) are considered as the chiral scalar partner of pseudoscalar nonet in SU(3) chiral symmetry, and the high mass scalar mesons a_0(1450), K^*_0(1430), f_0(1370) and f_0(1710) turned out to be considered as the L=1 q\bar{q} scalar mesons. We assume that the high mass of the L=1 q\bar{q} scalar mesons is caused by the mixing with the light scalar mesons. For the structure of the light scalar mesons, we adopted the qq\bar{q}\bar{q} model in order to explain the "scalar meson puzzle". The inter-mixing between the light scalar nonet and the high mass L=1 q\bar{q} nonet and the intra-mixing among each nonet are analyzed by including the glueball into the high mass scalar nonet.Comment: 16 pages, 5 figure

Cosmic ray sidereal diurnal variation of galactic origin observed by neutron monitors

Cosmic ray sidereal diurnal variations observed by neutron monitors are analyzed for the period 1961 to 1978, by adding 134 station years data to the previous paper (Nagashima, et al., 1983). Also the dependence of the sidereal variations on Sun's polar magnetic field polarity is examined for two periods; the period of negative polarity in the northern region, 1961 to 1969 and the period of positive polarity, 1970 to 1978. It is obtained that for the former period, the amplitude A=0.0203 + or 0.0020% and the phase phi=6.1 + or - 0.4 h LST and for the latter period, 0.0020% and phi=8.6 + or - 4 h LST, respectively

Metal-nonmetal transition in LixCoO2 thin film and thermopower enhancement at high Li concentration

We investigate the transport properties of LixCoO2 thin films whose resistivities are nearly an order of magnitude lower than those of the bulk polycrystals. A metal-nonmetal transition occurs at ~0.8 in a biphasic domain, and the Seebeck coefficient (S) is drastically increased at ~140 K (= T*) with increasing the Li concentration to show a peak of magnitude ~120 \muV/K in the S-T curve of x = 0.87. We show that T* corresponds to a crossover temperature in the conduction, most likely reflecting the correlation-induced temperature dependence in the low-energy excitations

Effects to Scalar Meson Decays of Strong Mixing between Low and High Mass Scalar Mesons

We analyze the mass spectroscopy of low and high mass scalar mesons and get the result that the coupling strengths of the mixing between low and high mass scalar mesons are very strong and the strengths of mixing for $I=1, 1/2$ scalar mesons and those of I=0 scalar mesons are almost same. Next, we analyze the decay widths and decay ratios of these mesons and get the results that the coupling constants $A'$ for $I=1, 1/2$ which represents the coupling of high mass scalar meson $N'$ -> two pseudoscalar mesons $PP$ are almost same as the coupling $A'$ for the I=0. On the other hand, the coupling constant $A$ for $I=1, I=1/2$ which represents the low mass scalar meson $N$ -> $PP$ are far from the coupling constant $A$ for I=0. We consider a resolution for this discrepancy. Coupling constant $A''$ for glueball $G$ -> $PP$ is smaller than the coupling $A'$. $\theta_P$ is $40^\circ \sim 50^\circ$.Comment: 15 pages, 6 figure

Anisotropic magnetic fluctuations in the ferromagnetic superconductor UCoGe studied by angle-resolved ^{59}Co NMR

We have carried out direction-dependent ^{59}Co NMR experiments on a single crystal sample of the ferromagnetic superconductor UCoGe in order to study the magnetic properties in the normal state. The Knight shift and nuclear spin-lattice relaxation rate measurements provide microscopic evidence that both static and dynamic susceptibilities are ferromagnetic with strong Ising anisotropy. We discuss that superconductivity induced by these magnetic fluctuations prefers spin-triplet pairing state.Comment: 4 pages, 4 figure

Anisotropy in the Antiferromagnetic Spin Fluctuations of Sr2RuO4

It has been proposed that Sr_2RuO_4 exhibits spin triplet superconductivity mediated by ferromagnetic fluctuations. So far neutron scattering experiments have failed to detect any clear evidence of ferromagnetic spin fluctuations but, instead, this type of experiments has been successful in confirming the existence of incommensurate spin fluctuations near q=(1/3 1/3 0). For this reason there have been many efforts to associate the contributions of such incommensurate fluctuations to the mechanism of its superconductivity. Our unpolarized inelastic neutron scattering measurements revealed that these incommensurate spin fluctuations possess c-axis anisotropy with an anisotropic factor \chi''_{c}/\chi''_{a,b} of \sim 2.8. This result is consistent with some theoretical ideas that the incommensurate spin fluctuations with a c-axis anisotropy can be a origin of p-wave superconductivity of this material.Comment: 5 pages, 3 figures; accepted for publication in PR

Evidence for incommensurate spin fluctuations in Sr_2RuO_4

We report first inelastic neutron scattering measurements in the normal state of Sr_2RuO_4 that reveal the existence of incommensurate magnetic spin fluctuations located at ${\bf q}_0=(\pm 0.6\pi/a, \pm 0.6\pi/a, 0)$. This finding confirms recent band structure calculations that have predicted incommensurate magnetic responses related to dynamical nesting properties of its Fermi surface

Incommensurate Magnetism around Vortices and Impurities in High-TcT_c Superconductors

By solving self-consistently an effective Hamiltonian including interactions for both antiferromagnetic spin-density wave (SDW) and d-wave superconducting (DSC) orderings, a comparison study is made for the local magnetic structure around superconducting vortices and unitary impurities. To represent the optimally doped regime of cuprates, the parameter values are chosen such that the DSC is dominant while the SDW is vanishingly small. We show that when vortices are introduced into the superconductor, an oscillating SDW is induced around them. The oscillation period of the SDW is microscopically found, consistent with experiments, to be eight lattice constants ($8a_0$). The associated charge-density wave (CDW) oscillates with a period of one half ($4a_0$) of the SDW. In the case of unitary impurities, we find a SDW modulation with identical periodicity, however without an associated CDW. We propose neutron scattering experiments to test this prediction.Comment: 5 pages, 4 eps figures (color) included in the tex