Three-Pronged Junctions on SO (2 N )/ U ( N ) and Sp ( N )/ U ( N )

  • PDF / 362,813 Bytes
  • 5 Pages / 612 x 792 pts (letter) Page_size
  • 54 Downloads / 270 Views

DOWNLOAD

REPORT


HYSICS OF ELEMENTARY PARTICLES AND ATOMIC NUCLEI. THEORY

Three-Pronged Junctions on SO(2N)/U(N) and Sp(N)/U(N) T. Kima, * and Su. Shina, ** a

Department of Physics and Institute of Basic Science, Sungkyunkwan University, Suwon, 16419 Republic of Korea *e-mail: [email protected] **e-mail: [email protected] Received November 15, 2019; revised January 15, 2020; accepted February 28, 2020

Abstract—We report on the results of our work [1], which discusses 1 = 2 nonlinear sigma models on the quadrics of the Grassmann manifold and three-pronged junctions of the mass-deformed nonlinear sigma models on SO(8)/U (4) and Sp(3)/U (3) . This article is prepared for the Proceedings of International Workshop “Supersymmetries and Quantum Symmetries—SQS’2019”, which was held in Yerevan from 26 to 31 August, 2019. The talk was based on [1]. DOI: 10.1134/S1547477120050222

It is shown in [2] that we can construct threepronged junctions of the mass-deformed nonlinear sigma model on the cotangent bundle of the Grassmann manifold in the moduli matrix formalism without using the Plücker embedding. We can apply the method to mass-deformed nonlinear sigma models on the other Hermitian symmetric spaces. The work [1] discussed 1 = 2 nonlinear sigma models on the quadrics of the Grassmann manifold and three-pronged junctions of the mass-deformed nonlinear sigma models. The hyper-Kähler nonlinear sigma model on the cotangent bundle of the Grassmann manifold N +M ) , [3–5] is T * GN + M ,M , GN + M ,M = SU (NSU)×(SU (M )×U (1)



S = d4x

{ d θ [Tr (ΦΦe 4



V

Φ J ΦT = 0,  0 IN  J = ,  eI N 0 

2

(3)

1, for SO(2N )/U (N ) (4) e= −1, for Sp(N )/U (N ).

The parametrisation (2) shows that the constraint (3), which is f T + ef = 0 , ensures that Ψ obeys

+ ΨΨ e −V − cV )]

+ d θ [Tr ( Ξ ( ΦΨ − bI M ))

}

manifold G2N,N. The Kähler nonlinear sigma models on SO(2N )/U (N ) and Sp(N )/U (N ) are embedded to the Kähler nonlinear sigma model on G2N ,N [6], which corresponds to (1) with Ψ = 0, by

ΨT J Ψ = 0. (1)

+ (conjugate transpose)] , (c ∈ R ≥0, b ∈ C). Chiral fields Φ and ΨT are M × (N + M ) matrices. Vector field V and complex field Ξ are M × M matrices. There are two cases b = 0 and b ≠ 0 , which are related by the SU (2)R symmetry. We study the b = 0 case in this paper. The superfields in this case can be parametrised [5] by

 − fg  (2) Φ = (I M f ) , Ψ =  .  g  We can show that f lives on the base Grassmann manifold whereas g lives on the cotangent space [3, 5]. The Hermitian symmetric spaces SO(2N )/U (N ) and Sp(N )/U (N ) are submanifolds of the Grassmann

(5)

Therefore the only consistent 1 = 2 nonlinear sigma models on SO(2N )/U (N ) and Sp(N )/U (N ) for b = 0 is obtained by imposing constraints (3) and (5) on the model (1) with b = 0 [1]. The mass-deformed nonlinear sigma models [1] are obtained by adding the potential terms that are discussed in [5]:



S = d x 4

{ d θ [Tr (ΦΦe 4

V

+ ΨΨ e

−V

+ d θ Tr ( ΞΦΨ + Φ M Ψ



− cV )]

2

}

(6)

+ Φ 0Φ J ΦT + Ψ 0 ΨT J Ψ ) + (c.t.) . The models (6) have discret