Nucleon Electric Dipole Moments in High-Scale Supersymmetric Models

The electric dipole moments (EDMs) of electron and nucleons are promising probes of the new physics. In generic high-scale supersymmetric (SUSY) scenarios such as models based on mixture of the anomaly and gauge mediations, gluino has an additional contribution to the nucleon EDMs. In this paper, we studied the effect of the $CP$-violating gluon Weinberg operator induced by the gluino chromoelectric dipole moment in the high-scale SUSY scenarios, and we evaluated the nucleon and electron EDMs in the scenarios. We found that in the generic high-scale SUSY models, the nucleon EDMs may receive the sizable contribution from the Weinberg operator. Thus, it is important to compare the nucleon EDMs with the electron one in order to discriminate among the high-scale SUSY models.Comment: 22 pages, 8 figures, Version accepted for publication in JHE

Perturbative Unitarity of Strongly Interacting Massive Particle Models

Dark pion is a promising candidate for the strongly interacting massive particle dark matter. A large pion self-coupling $m_\pi/f_\pi$ tends to be required for correct relic abundance, and hence the partial-wave amplitudes can violate the perturbative unitarity even for the coupling within na\"ive perturbative regime. We improve the partial-wave amplitudes in order to satisfy the optical theorem. We demonstrate that the improvement is relevant only for semi-relativistic pions, and thus this does not affect the self-scattering cross section at the cosmic structures. We also discuss the impact of the improvement of the $\pi \pi \pi \to \pi \pi$ scattering process, and we find that there is an upper bound on $m_\pi$ at which the correct relic abundance is never achieved even at large $m_\pi/f_\pi$ due to the optical theorem.Comment: 17+26 pages, 5 figure

Spin Susceptibility of a J=3/2 Superconductor

We discuss the spin susceptibility of superconductors in which a Cooper pair consists of two electrons having the angular momentum J=3/2 due to strong spin-orbit interactions. The susceptibility is calculated analytically for pseudospin quintet states in a cubic superconductor within the linear response to a Zeeman field. The susceptibility for $A_{1g}$ symmetry states is isotropic in real space. For $E_g$ and $T_{2g}$ symmetry cases, the results depend sensitively on choices of order parameter. The susceptibility is isotropic for a $T_{2g}$ symmetry state, whereas it becomes anisotropic for an $E_{g}$ symmetry state. We also find in a $T_{2g}$ state that the susceptibility tensor has off-diagonal elements.Comment: 11 pages, 3 figure

NH3 in the Galactic Center is formed in Cool Conditions

It is an open question why the temperature of molecular gas in the Galactic center region is higher than that of dust. To address this problem, we made simultaneous observations in the NH_3 (J,K) = (1,1), (2,2), and (3,3) lines of the central molecular zone (CMZ) using the Kagoshima 6 m telescope. The ortho-to-para ratio of NH_3 molecules in the CMZ is 1.5--3.5 at most observed area. This ratio is higher than the statistical equilibrium value, and suggests that the formation temperature of NH_3 is 11--20 K. This temperature is similar to the dust temperature estimated from the submillimeter and infrared continuum. This result suggests that the NH_3 molecules in the CMZ were produced on dust grains with the currently observed temperature (11--20 K), and they were released into the gas phase by supernova shocks or collisions of dust particles. The discrepancy between warm molecular gas and cold dust can be explained by the transient heating of the interstellar media in the CMZ approximately 10^5 years ago when the NH_3 molecules were released from the dust.Comment: 19 pages, 12 figures, accepted for PAS