Three-body-interaction effects on the relativistic perihelion precession for the Sun-Jupiter-Saturn system
The relativistic perihelion precession due to the three-body interaction is derived. We consider a hierarchical coplanar three-body system, such as the Sun, Jupiter and Saturn, in which both the secondary object as the largest planet corresponding to Jupiter (mass $m_2$) and the third one corresponding to Saturn (mass $m_3$) orbit around the primary object corresponding to Sun (mass $m_1 \gg m_2 \gg m_3$), where the mean orbital radius of the third body is larger than that of the secondary one (denoted as $\ell$). We investigate the post-Newtonian effects on the motion of the third body (semimajor axis a, eccentricity e for the Keplerian orbital elements). Under some assumptions with a certain averaging, the relativistic perihelion precession of the third mass by the post-Newtonian three-body interaction is expressed as $6 G m_2 \ell^2 c^{-2} a^{-3} n (1+9e^2/16) (1-e^2)^{-3} $, where G and c denote the gravitational constant and the speed of light, respectively, and the mean motion for the third body is denoted as $n = 2\pi a^{3/2} G^{-1/2} (m_1+m_2)^{-1/2}$. For the Sun-Jupiter-Saturn system, it is $7.8 \times 10^{-6}$ arcsec/cy. This is larger than the Lense-Thirring effect by Sun but it cannot yet explain the recently reported value for the anomalous perihelion precession of Saturn as $-0.006 \pm 0.002$ arcsec/cy by Iorio (2009) based on the analyses by Pitjeva with the EPM2008 ephemerides.

title: Possible daily and seasonal variations in quantum interference induced by Chern-Simons gravity.
abstract: 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: 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: Possible latitude effects of Chern-Simons gravity on quantum interference
abstract: It has been recently suggested that possible effects of Chern-Simons gravity on a quantum interferometer are dependent on the latitude and direction of the interferometer on Earth in orbital motion around Sun. Continuing work initiated in the earlier publication [Okawara, Yamada and Asada,  (2012)], we perform numerical calculations of time variation in the induced phase shifts for nonequatorial cases. We show that the maximum phase shift at any latitude might occur at 6, 0 (and 12), and 18 hours (in local time) of each day, when the normal vector to the interferometer is vertical, eastbound and northbound, respectively. If two identical interferometers were located at different latitudes, the difference between two phase shifts that are measured at the same local time would be $O(\sin \delta\varphi)$ for a small latitude difference $\delta\varphi$. It might thus become maximally $\sim 20$ percents for $\delta\varphi \sim 10$ degrees, for instance.

title: Marginally stable circular orbit of a test body in spherically symmetric and static spacetimes
abstract: We study a marginally stable circular orbit (MSCO) such as the innermost stable circular orbit (ISCO) of a timelike geodesic in any spherically symmetric and static spacetime. It turns out that the metric components are separable from the constants of motion along geodesics. We show also that a metric component $g_{rr}$ with a radial coordinate $r$ does not affect MSCOs. This suggests that, as a test of gravity, any ISCO measurement may be put into the same category as gravitational redshift experiments. MSCOs for exact solutions to the Einstein's equation are also mentioned.

title: Improving the moment approach for astrometric binaries: possible application to Cygnus X-1
abstract: A moment approach for orbital determinations of astrometric binaries from astrometric observations alone has been recently studied for a low signal-to-noise ratio (Iwama et al. 2013, PASJ, 65, 2). Through avoiding a direct use of the time-consuming Kepler equation, temporalinformationistakenintoaccount toincrease theaccuracy ofstatistical moments. As numerical tests, 100 realizations are done and the mean value and the standard deviation are also evaluated. For a semimajor axis, the difference between the mean of the recovered values and the true value decreases to less than a tenth in the case of 10000 observed points. Therefore, the present approach works better than the previous one for orbital determinations when one has a large number of observed points. The present approach is thus applicable to CygX-1.

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: 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: Regge trajectories of mesons and baryons and a universal spring

title: The D(s)(2317) and D(s)(2459) mesons in ~U(12)-classification scheme of hadrons
abstract: The narrow mesons, DsJ*(2317) and DsJ(2460), observed recently in the final states Ds+ pi0 and Ds*+ pi0 are pointed out to be naturally assigned as the ground-state scalar and axial-vector chiral states in the csbar system, which would newly appear in the covariant U~(12) hadron-classification scheme proposed a few years ago. We predict the comparatively large electromagnetic decay widths to other models, which are due to the intrinsic electric dipole moment. The SELEX state DsJ(2632) is also able to be assigned to the P-wave chiral state with JP=1- in the U~(12)-classification scheme.

title: One-gluon exchange effects on linear meson trajectories in the covariant oscillator quark model
abstract: SummaryWe investigate one-gluon exchange effects on the linear Regge trajectories of all quark-antiquark meson systems, from light through heavy quarks, in the framework of the covariant oscillator quark model. This model gives linearly rising trajectories to both orbitally and radially excited states in the limit of neglecting perturbative QCD effects. We find that the spin-independent one-gluon exchange interaction barely affects the orbital excitations, preserving the well-known linearity of the leading Regge trajectories, but for the radial excitations it makes an appropriate contribution, in conformity with the observed behaviour largely deviating from the linear trajectories. We also calculate the hyperfine mass splittings of all ground-stateS-wave mesons. For as yet unknown mass splittings, we findM(B*c)−M(Bc)≈50 MeV andM(Y)−M(ηb)≈49 MeV.