arXiv subjects

Akihiro Murayama

Publications and source records attributed to Akihiro Murayama.

6 recordsLinked to original sources

arXiv2004

Quantum Dynamics of a Bulk-Boundary System

The quantum dynamics of a bulk-boundary theory is closely examined by the use of the background field method. As an example we take the Mirabelli-Peskin model, which is composed of 5D super Yang-Mills (bulk) and 4D Wess-Zumino (boundary). Singular interaction terms play an important role of canceling the divergences coming from the KK-mode sum. Some new regularization of the momentum integral is proposed. An interesting background configuration of scalar fields is found. It is a localized solution of the field equation. In this process of the vacuum search, we present a new treatment of the vacuum with respect to the extra coordinate. The "supersymmetric" effective potential is obtained at the 1-loop full (w.r.t. the coupling) level. This is the bulk-boundary generalization of the Coleman-Weinberg's case. Renormalization group analysis is done where the correct 4d result is reproduced. The Casimir energy is calculated and is compared with the case of the Kaluza-Klein model.

hep-th↗

arXiv2004

Family of Singular Solutions in A SUSY Bulk-Boundary System

A set of classical solutions of a singular type is found in a 5D SUSY bulk-boundary system. The "parallel" configuration, where the whole components of fields or branes are parallel in the iso-space, naturally appears. It has three {\it free} parameters related to the {\it scale freedom} in the choice of the brane-matter sources and the {\it "free" wave} property of the {\it extra component} of the bulk-vector field. The solutions describe brane, anti-brane and brane-anti-brane configurations depending on the parameter choice. Some solutions describe the localization behaviour even after the non-compact limit of the extra space. Stableness is assured. Their meaning in the brane world physics is examined in relation to the stableness, localization, non-singular (kink) solution and the bulk Higgs mechanism.

hep-th↗

arXiv2004

A Bulk Effect to SUSY Effective Potential in a 5D Super-Yang-Mills Model

Supersymmetric effective potential of a 5D super-Yang-Mills model compactified on $S^1/Z_2$, i.e., on an interval $l$ of extra dimension, is estimated at the 1-loop level by the auxiliary field tadpole method. For the sake of infinite towers of Kaluza-Klein excitation modes of bulk fields involved in the tadpoles, there arises a definite bulk effect of linear growth of the effective potential along with the cutoff ${\mitΛ}$ which is greatly suppressed by $l$ to produce finite contributions. The minimization of the effective potential incorporating the tree potential and a Fayet-Iliopoulos $D$-term reveals an interesting case that the size of $l$ is stabilized at a length corresponding to an intermediate mass scale $10^{12-14}$ GeV.

hep-th↗

arXiv2004

Brane-Anti-Brane Solution and SUSY Effective Potential in Five Dimensional Mirabelli-Peskin Model

A localized configuration is found in the 5D bulk-boundary theory on an $S_1/Z_2$ orbifold model of Mirabelli-Peskin. A bulk scalar and the extra (fifth) component of the bulk vector constitute the configuration. $\Ncal=1$ SUSY is preserved. The effective potential of the SUSY theory is obtained using the background field method. The vacuum is treated in a general way by allowing its dependence on the extra coordinate. Taking into account the {\it supersymmetric boundary condition}, the 1-loop full potential is obtained. The scalar-loop contribution to the Casimir energy is also obtained. Especially we find a {\it new} type which depends on the brane configuration parameters besides the $S_1$ periodicity parameter.

hep-th↗

arXiv2004

Casimir Effect in the Brane World

Taking the Mirabelli-Peskin model, we examine the Casimir effect in the brane world. It is compared with that of the ordinary Kaluza-Klein theory.

hep-th↗

arXiv1997

Some Advantages of SUSY SU(4) x SU(2)_L x SU(2)_R Model in String Derived SO(10) GUTs

A D-parity violated SUSY SU(4) x SU(2) _ L x SU(2)_R gauge model with the Higgs sector 2{(4,1,2)+(4-bar,1, 2)}+(1,2,2)+some(1,1,1)'s is shown to have the following advantages: (i) It is the simplest and almost unique solution that satisfies M_X = M_{string} ~0.6 x 10^{18} GeV and M_{INT} ~ 5 x10^{11} GeV in superstring derived SUSY SO(10) GUTs. (ii) The proton is stable enough by the automatic "doublet-triplet splitting" closely connected with the D-parity violation. (iii) The minimization of SUSY one-loop effective potential in a toy model suggests that the SO(10) gauge theory tends to break dynamically down to the SU(4) x SU(2)_ L x SU(2)_R model.

hep-ph↗