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Tomohiro Matsuda

Publications and source records attributed to Tomohiro Matsuda.

97 records · Page 6Linked to original sources

Alternative Approach to Gaugino Condensation

We examine the mechanism of gaugino condensation in supersymmetric theories within a Nambu-Jona-Lasinio type approach. We investigate the effective Lagrangian description of higher energy theories that include some moduli fields in the gauge coupling constant. First we consider supersymmetric QCD with and without a mass term. We can find a phase transition in massless theory, but when we add a mass term, such a phase transition disappears. We also examine a model with a dilaton dependent coupling constant and find that it is very similar to supersymmetric QCD. Application of our method to supergravity is also examined.

hep-ph↗

Large N Expansion and Softly Broken Supersymmetry

We examine the supersymmetric non-linear O(N) sigma model with a soft breaking term. In two dimensions, we found that the mass difference between supersymmetric partner fields vanishes accidentally. In three dimensions, the mass difference is observed but O(N) symmetry is always broken also in the strong coupling region.

hep-ph↗

Tadpole Method and Supersymmetric O(N) Sigma Model

We examine the phase structures of the supersymmetric O(N) sigma model in two and three dimensions by using the tadpole method. Using this simple method, the calculation is largely simplified and the characteristics of this theory become clear. We also examine the problem of the fictitious negative energy state.

hep-ph↗

Gaugino Condensation in the Early Universe

We examine the process of formation of the gaugino condensation within a Nambu-Jona-Lasinio type approach. We construct an effective Lagrangian description for the gaugino condensation which include a Weyl compensator superfield whose vacuum expectation value is related to the gaugino condensation.

hep-ph↗

On gaugino condensation in the effective theory

We analyze the gaugino condensation in the effective theory for N=1 SU(N) Supersymmetric QCD with $N_{f}$ flavors. It is known that taking the vacuum expectation value of the matter field to be infinite, we can show that gaugino condensation can occur. At such a limit we should consider only pure supersymmetric Yang-Mills theory. But when we include an interaction term of order $O(\frac{1}{v})$, the situation can change. We analyze the effect of this interaction term and examine the gaugino condensation in the low energy Yang-Mills theory by using the scheme of Nambu-Jona-Lasinio.

hep-th↗

Comment on a mechanism of dynamical breaking of supersymmetry

We re-examine the so-called Nambu-Jona-Lasinio mechanism suggested by Song, Xu and Chin in breaking the supersymmetry in the Wess-Zumino model and show that this mechanism cannot be justified without assuming special effects between fermions. The fermion condensation suggested by them corresponds to an unstable vacuum configuration. As a result, there is no fermion condensation and no supersymmetry breaking in the model discussed by them.

hep-ph↗

Natural explanation for discrete R-symmetry in successful inflation in N=1 supergravity

Recently it was shown that discrete R-invariance in superpotential can lead to a successful flat potential in inflation. We suggest that this discrete R-symmetry arises from an underlying supersymmetric gauge theory, which gives rise to a scalar inflaton as a composite field. This discrete R-symmetry is common to the dynamical breaking scenarios in global supersymmetry studied several years ago. Some extension of the R-invariance method is also shown.

hep-ph↗