Measurement of branching fractions for B-->eta(c)K(*) decays

We report measurements of branching fractions for charged and neutral B-->eta(c)K decays where the eta(c) meson is reconstructed in the K(0)(S)K+/-pi(-/+), K+K-pi(0), K(*0)K-pi(+), and pp; decay channels. The neutral B0 channel is a CP eigenstate and can be used to measure the CP violation parameter sin(2phi(1). We also report the first observation of the B0-->eta(c)K(*0) mode. The results are based on an analysis of 29.1 fb(-1) of data collected by the Belle detector at KEKB.     

Transverse josephson plasma mode in T* cuprate superconductors

A transverse optical plasma mode is observed at far-infrared frequencies within the superconducting gap region by measuring the c-axis optical reflectivity for single crystals of T* cuprate superconductors SmLa0.85Sr0.15CuO4-delta and Nd1.4Sr0.4Ce0.2CuO4-delta. These T* cuprates have two different insulating layers sandwiching the superconducting CuO2 planes, leading to two longitudinal plasmons. Also, the transverse mode is directly observed due to the coupling of the infrared radiation with the current perpendicular to the superconducting layers which are regarded as an alternating array of two inequivalent Josephson junctions.     

Measurement of B(0)(d)-B_(0)(d) mixing rate from the time evolution of dilepton events at the upsilon(4S)

We report a determination of the B(0)(d)-&B_(0)(d) mixing parameter Deltam(d) based on the time evolution of dilepton yields in Upsilon(4S) decays. The measurement is based on a 5.9 fb(-1) data sample collected by the Belle detector at KEKB. The proper-time difference distributions for same-sign and opposite-sign dilepton events are simultaneously fitted to an expression containing Deltam(d) as a free parameter. Using both muons and electrons, we obtain Deltam(d) = 0.463+/-0.008 (stat)+/-0.016 (syst) ps(-1). This is the first determination of Deltam(d) from time evolution measurements at the Upsilon(4S). We also place limits on possible CPT violations.     

Zero-magnetization ferromagnet proven by helicity-switching Compton scattering

A single crystal of gadolinium-doped SmAl(2) has zero magnetization in the midst of the ordered temperature region, despite the probable ferromagnetic spin ordering. The asymmetry in Compton-scattering intensity when switching between right- and left-handed polarization of incident 150-keV synchrotron radiation provides decisive proof that ferromagnetic order is really there, and that spin and orbital magnetic contributions cancel. The experiments also show that the spin direction at this zero-magnetization state is rather stable against the external magnetic field and, nevertheless, reversible by a preceding control of temperature and an external field.     

Observation of large CP violation in the neutral B meson system

We present a measurement of the standard model CP violation parameter sin2 phi(1) based on a 29.1 fb(-1) data sample collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. One neutral B meson is fully reconstructed as a J/psi K(S), psi(2S)K(S), chi(c1)K(S), eta(c)K(S), J/psi K(L), or J/psi K(*0) decay and the flavor of the accompanying B meson is identified from its decay products. From the asymmetry in the distribution of the time intervals between the two B meson decay points, we determine sin2 phi(1) = 0.99+/-0.14(stat)+/-0.06(syst). We conclude that we have observed CP violation in the neutral B meson system.     

Absence of residual quasiparticle conductivity in the underdoped cuprate YBa2Cu4O8

We report measurements of the in-plane thermal conductivity kappa of the stoichiometric underdoped cuprate YBa2Cu4O8 (Y124) below 1 K. kappa(T) is shown to follow a simple phononic T3 dependence at the lowest temperature T for both current directions, with a negligible linear quasiparticle contribution. This observation is in marked contrast with behavior reported in optimally doped cuprates, and implies that extended zero-energy (or low-energy) quasiparticles are absent in Y124.     

Incident-angle dependence of the sensitivity of second-harmonic generation of an oxacyanine dye in an LB film.

The second-harmonic generation of a cyanine dye in an LB film was investigated by varying the incident angle of the excitation laser. There was a clear dependence on the incident angle, which was simulated by a simple model. Thus, a highly sensitive determination should be carried out at such an angle where the efficiency of the second-harmonic generation shows its maximum.     

Mössbauer and NMR studies of iron-carbon martensite

The atomic arrangements in Fe-C martensite, especially the interstitial carbon positions have been discussed utilizing⁵⁷Fe Mössbauer spectroscopy and¹³C and⁵⁷Fe spin-echo NMR measurements. The experimental result is well explained by the model of two interstices occupancy of carbon in the bct martensite. Especially, the spin-echo spectra by¹³C nuclei showed that two main lines first appear and clear satellite lines gradually rise during the aging at 323K, suggesting the carbon jumps from the tetrahedral to the octahedral interstices and further movements to form a local ordered arrangement.     

A characterization of isotropic immersions by extrinsic shapes of smooth curves

In this paper we show that an isometric immersion is isotropic in the sense of O'Neill if and only if it preserves logarithmic derivatives of first geodesic curvatures of some curves.