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Weak Interaction Singlet and Strong CP Invariance
Strong $\mathrm{CP}$ invariance is automatically preserved by a spontaneously broken chiral ${\mathrm{U}(1)}_{4}$ symmetry. A weak-interaction singlet heavy quark $Q$, a new scalar mesonExpand
Axions and the Strong CP Problem
Current upper bounds on the neutron electric dipole moment constrain the physically observable quantum chromodynamic (QCD) vacuum angleExpand
Completing natural inflation
If the inflaton is a pseudo-scalar axion, the axion shift symmetry can protect the flatness of its potential from too large radiative corrections. This possibility, known as natural inflation,Expand
The μ-problem and the strong CP-problem
Abstract We investigate a possible connection of a solution of the strong CP-problem and the generation of a mass term μ in the low energy Higgs superpotential of supersymmetric models. ThisExpand
Light Pseudoscalars, Particle Physics and Cosmology
Abstract We review physics of light pseudoscalars (axions, majorons and familons) and their effects in cosmology. The axions which solve the strong CP problem play important roles in astrophysics andExpand
Cosmological gravitino regeneration and decay
Abstract We present a detailed study of gravitino production and decay subsequent to cosmological inflation. We calculate the cross sections for gravitino production in collisions of particles in theExpand
Update of axion CDM energy density
We improve the estimate of the axion CDM energy density by considering the new values of current quark masses, the QCD phase transition effect and a possible anharmonic effect.
Axinos as dark matter
Supersymmetric extensions of the Standard Model that incorporate the axion solution to the strong CP problem necessarily contain also the axino, the fermionic partner of the axion. In contrast to theExpand
We show that axinos produced in the early Universe in the decay of the lightest neutralinos are a compelling candidate for cold dark matter. We argue that axinos may well provide the main componentExpand