476 research outputs found
Dynamically Favored Chiral Symmetry Breakings in Supersymmetric Quantum Chromodynamics
By the use of an effective superpotential in supersymmetric quantum
chromodynamics (SQCD) with N_f flavors and N_c colors of quarks for N_f>=N_c+2,
the influence of soft supersymmetry (SUSY) breakings is examined to clarify
dynamics of chiral symmetry breakings near the SUSY limit. In case that SQCD
triggers spontaneous chiral symmetry breakings, it is possible to show that our
superpotential dynamically favors the successive formation of condensates,
leaving either SU(N_f-N_c) or SU(N_f-N_c+1) unbroken as a chiral nonabelian
symmetry.Comment: 7 pages by RevTeX (with a note added
Matrix model and Yukawa couplings on the noncommutative torus
The IKKT model is proposed as a non-perturbative formulation of superstring
theory. We propose a Dirac operator on the noncommutative torus,which is
consistent with the IKKT model, based on noncommutative geometry. Next, we
consider zero-mode equations of the Dirac operator with magnetic fluxes. We
find that zero-mode solutions have the chirality and the generation structures
similar to the commutative case. Moreover, we compute Yukawa couplings of
chiral matter fields.Comment: 32 pages, no figure, v3 published versio
Superstring Backgrounds in String Geometry
String geometry theory is a candidate of the non-perturbative formulation of
string theory. In order to determine the string vacuum, we need to clarify how
superstring backgrounds are described in string geometry theory. In this paper,
we show that all the type IIA, IIB, SO(32) type I, and SO(32) and heterotic superstring backgrounds are embedded in configurations of the
fields of a single string geometry model. Especially, we show that the
configurations satisfy the equations of motion of the string geometry model in
if and only if the embedded string backgrounds satisfy the
equations of motion of the supergravities, respectively. This means that
classical dynamics of the string backgrounds are described as a part of
classical dynamics in string geometry theory. Furthermore, we define an energy
of the configurations in the string geometry model because they do not depend
on the string geometry time. A string background can be determined by
minimizing the energy.Comment: 15 pages. arXiv admin note: text overlap with arXiv:2003.1248
Effects of Z-Isomerization on the Bioavailability and Functionality of Carotenoids: A Review
Carotenoids, the most common fat-soluble plant pigments in nature, are beneficial to human health due to their strong antioxidant activities and abilities to prevent various diseases. Carotenoids have many geometrical isomers forms caused by E/Z-isomerization at arbitrary sites within the multiple conjugated double bonds. Several studies have addressed that the bioavailability as well as the antioxidant, anticancer, and antiatherosclerotic activities of carotenoids varies among the isomers. In addition, those variations differ among carotenoids: Z-isomerization resulted in “positive” or “negative” effect for carotenoids bioavailability and functionality, for example, Z-isomers of lycopene are more bioavailable than the all-E-isomer, whereas the opposite is observed for β-carotene. Thus, to efficiently promote the beneficial effects of carotenoids by ingestion, it is important to have a good understanding of the impact of E/Z-isomerization on the corresponding functional changes. The objective of this contribution is to review the effects of carotenoid Z-isomerization on bioavailability and functionality and describe their differences among carotenoids
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