664 research outputs found
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 -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 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 scattering process, and we find
that there is an upper bound on at which the correct relic abundance is
never achieved even at large due to the optical theorem.Comment: 17+26 pages, 5 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
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 symmetry states is isotropic
in real space. For and symmetry cases, the results depend
sensitively on choices of order parameter. The susceptibility is isotropic for
a symmetry state, whereas it becomes anisotropic for an
symmetry state. We also find in a state that the susceptibility tensor
has off-diagonal elements.Comment: 11 pages, 3 figure
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