Possible daily and seasonal variations in quantum interference induced by Chern-Simons gravity.
Possible effects of Chern-Simons (CS) gravity on a quantum interferometer turn out to be dependent on the latitude and direction of the interferometer on Earth in orbital motion around the Sun. Daily and seasonal variations in phase shifts are predicted with an estimate of the size of the effects, wherefore neutron interferometry with ~5 m arm length and ~10(-4) phase measurement accuracy would place a bound on a CS parameter comparable to the Gravity Probe B satellite.

title: Triangular solution to the general relativistic three-body problem for general masses
abstract: Continuing work initiated in an earlier publication [Ichita, Yamada and Asada,  (2011)], we reexamine the post-Newtonian effects on Lagrange's equilateral triangular solution for the three-body problem. For three finite masses, it is found that a triangular configuration satisfies the post-Newtonian equation of motion in general relativity, if and only if it has the relativistic corrections to each side length. This post-Newtonian configuration for three finite masses is not always equilateral and it recovers previous results for the restricted three-body problem when one mass goes to zero. For the same masses and angular velocity, the post-Newtonian triangular configuration is always smaller than the Newtonian one.

title: Post-Newtonian effects of planetary gravity on the perihelion shift
abstract: We consider a coplanar system comprising of a massive central body (a star), a less massive secondary (a planet) on a circular orbit, and a test particle on a bound orbit exterior to that of the secondary. The gravitational pull exerted on the test particle by the secondary acts as a small perturbation, wherefore the trajectory of the particle can be described as an ellipse of a precessing perihelion. While the apsidal motion is defined overwhelmingly by the Newtonian portion of the secondary’s gravity, the post-Newtonian portion, too, brings its tiny input. We explore whether this input may be of any astrophysical relevance in the next few decades. We demonstrate that the overall post-Newtonian input of the secondary’s gravity can be split into two parts. One can be expressed via the orbital angular momentum of the secondary and another via its orbital radius. Despite some moderately large numerical factors showing up in the expressions for these two parts, the resulting post-Newtonian contributions from the secondary’s gravity into the apsidal motion of the test particle turn out to be small enough to be neglected in the near-future measurements.

title: Moment Approach to Determining the Orbital Elements of an Astrometric Binary with a Low Signal-to-Noise Ratio
abstract: A moment approach to the orbit determination of an astrometric binary with a low signal-to-noise ratio from astrometric observations alone is proposed, especially aiming at a close binary system with a short orbital period, such as Cyg X-1, and also at a star wobbled by planets. As an exact solution to the nonlinearly coupled equation, the orbital elements are written in terms of the second and third moments of projected positions that are measured by astrometry. This may hold the possibility of the true orbit estimate.

title: Collinear solution to the general relativistic three-body problem
abstract: The three-body problem is reexamined in the framework of general relativity. The Newtonian three-body problem admits Euler's collinear solution, where three bodies move around the common center of mass with the same orbital period and always line up. The solution is unstable. Hence, it is unlikely that such a simple configuration would exist owing to general relativistic forces dependent not only on the masses but also on the velocity of each body. However, we show that the collinear solution remains true with a correction to the spatial separation between masses. Relativistic corrections to the Sun-Jupiter Lagrange points L{sub 1}, L{sub 2}, and L{sub 3} are also evaluated.

title: Possible altitudinal, latitudinal, and directional dependence of the relativistic Sagnac effect in Chern-Simons modified gravity
abstract: Toward a test of parity violation in a gravity theory, possible effects of Chern-Simons (CS) gravity on an interferometer have been recently discussed. Continuing work initiated in an earlier publication [Okawara, Yamada and Asada,  (2012)], we study possible altitudinal and directional dependence of relativistic Sagnac effect in CS modified gravity. We compare the CS effects on Sagnac interferometers with the general relativistic Lense-Thirring (LT) effects. Numerical calculations show that the eastbound Sagnac interferometer might be preferred for testing CS separately, because LT effects on this interferometer cancel out. The size of the phase shift induced in the CS model might have an oscillatory dependence also on the altitude of the interferometer through the CS mass parameter $m_{CS}$. Therefore, the international space station site as well as a ground-based experiment is also discussed.

title: Properties of the Ground-State q bar q Mesons and Possible Classification of Observed Mesons in the U~(12)_SF X O(3,1)_L Scheme
abstract: We examine possible assignments for known mesons to the predicted ground-state q bar q multiplets in the U~(12)_SF-classification scheme of hadrons, based on their observed properties. The masses of missing members of the ground-state multiplets are estimated, using a phenomenological mixing scheme for the normal- and extra-spin wave functions specific to this classification scheme. We also examine experimental candidates for the excited 1P, 1D and 2S multiplets in a framework of the U~(12)_SF X O(3,1)_L-classification scheme, based on the analysis of the ground-state masses. Then we see that the two exotic mesons pi_1(1400) and pi_1(1600) with J^PC=1^-+ have suitable masses to be assigned to the P-wave excitation and also there are a number of observed mesonic states which could be classified in terms of the U~(12)_SF X O(3,1)_L scheme.

title: Light-quark meson spectrum in the covariant oscillator quark model with one-gluon-exchange effects
abstract: The covariant oscillator quark model, which was extended recently to include one-gluon-exchange effects, is applied to investigate the mass spectrum of light-quark mesons. In the meson rest frame our effective potential due to one-gluon exchange is given as the sum of a Coulomb-type, orbit-orbit-like, spin-orbit, and hyperfine interaction, and has similar general features as in the standard nonrelativistic quark model. However, there are essential differences between them. First, our scheme is manifestly covariant and the potential is concerned with the squared masses of hadrons. Second, our effective one-gluon-exchange potential is greatly modified due to the covariant nature and the retardation effect. Owing to these modifications our model reproduces quite well the experimental behavior of the spectra of radially excited states as well as orbitally excited states.

title: A Novel View of Exotic Hadrons and the Covariant Ũ(12)‐Classification Scheme
abstract: I classify exotic hadrons into two types, “genuine” and “hidden” exotics, and propose that the “hidden” exotics would be interpreted as “chiralons” in the Ũ(12)SF×O(3,1)L‐classification scheme of hadrons. Based upon this conjecture I investigate the mass spectrum of 1S, 1P, and 2S states for the cc system by use of a phenomenological mass formula with the spin‐dependent interactions and present possible assignments for exotic neutral charmonium‐like states which were recently discovered. It is also mentioned that some JPC‐exotic states predicted in this scheme might correspond to those found in a recent lattice QCD calculation of the charmonium spectrum.

title: Is the f1(1420) Our First Hybrid Meson

title: Baryon magnetic moments in the covariant oscillator quark model with unequal constituent masses
abstract: The baryon magnetic moments are investigated, applying the recently extended covariant oscillator quark model with unequal constituent masses. In this model covariant expressions for conserved hadron currents are explicitly given, and the moments are necessarily given in the unit of intrinsic particle magneton from the quark moments with some modified factors. Remarkably improved results over the simple quark-model calculations are obtained.