Symmetric Mass Generation

In recent years a consensus has gradually been reached that the previously proposed deconfined quantum critical point (DQCP) for spin-1/2 systems, an archetypal example of quantum phase transition beyond the classic Landau's paradigm, actually does not correspond to a true unitary conformal field theory (CFT). In this work we carefully investigate another type of quantum phase transition supposedly beyond the similar classic paradigm, the so called ``symmetric mass generation...

Summary talk presented at the Conference on Lattice Field Theory, Amsterdam, September, 1992. Abstract: The status of several proposals for defining a theory of chiral fermions on the lattice is reviewed and some new estimates for the upper bound on the Higgs mass are presented.

Lattice regularization of chiral fermions has been a long-standing problem in physics. In this work, we present the density matrix renormalization group (DMRG) simulation of the 3-4-5-0 model of (1+1)D chiral fermions with an anomaly-free chiral U(1) symmetry, which contains two left-moving and two right-moving fermions carrying U(1) charges 3,4 and 5,0, respectively. Following the Wang-Wen chiral fermion model, we realize the chiral fermions and their mirror partners on the ...

I review the problem of formulating chiral symmetry in lattice gauge theory. I discuss recent approaches involving an infinite tower of additional heavy states to absorb Fermion doublers. For hadronic physics this provides a natural scheme for taking quark masses to zero without requiring a precise tuning of parameters. A mirror Fermion variation provides a possible way of extending the picture to chirally coupled light Fermions. Talk presented at "Quark Confinement and the H...

The foundations of the mass generation mechanism of particles are reviewed. The Spontaneous Symmetry Breaking (SSB) process within the standard model (SM) and the minimal supersymmetric standard model (MSSM) is used to explore the present status of the Higgs Mechanism along with the constraints in detecting the Higgs particles in experiments. The possible explanations and generalizations for the case that the Higgs particles should not appear or to couple the Higgs Mechanism ...

Taking inspiration from lattice QCD data, we argue that a finite non-perturbative contribution to the quark mass is generated as a consequence of the dynamical phenomenon of spontaneous chiral symmetry breaking, in turn triggered by the explicitly breaking of chiral symmetry induced by the critical Wilson term in the action. In pure lattice QCD this mass term cannot be separated from the unavoidably associated linearly divergent contribution. However, if QCD is enlarged to a ...

A dynamical mechanism of symmetry breaking in which gauge and matter fields play an active role is proposed. It basically represents a covariant generalization of the mechanism responsible for superconductivity, and provides a {\em natural} mechanism of generation of mass which is not in conflict with the present value of the cosmological constant. When applied to SU(2)$\times$U(1) leads to exactly the same physics (Lagrangian density) as the Standard Model but modifying {\em...

I study the prospect of generating mass for symmetry-protected fermions without breaking the symmetry that forbids quadratic mass terms in the Lagrangian. I focus on 1+1 spacetime dimensions in the hope that this can provide guidance for interacting fermions in 3+1 dimensions. I first review the SO(8) Gross-Neveu model and emphasize a subtlety in the triality transformation. Then I focus on the "m = 0" manifold of the SO(7) Kitaev-Fidkowski model. I argue that this theory exh...

We suggest a new mass generation mechanism for gauge fields. The quantum field theory constructed in this paper is nonabelian, gauge invariant and asymptotically free.

It is shown numerically, in a chiral U(1) gauge Higgs theory in which the left and right-handed fermion components have opposite U(1) charges, that the spectrum of gauge and Higgs fields surrounding a static fermion contains both a ground state and at least one stable excited state. To bypass the difficulties associated with dynamical fermions in a lattice chiral gauge theory we consider only static fermion sources in a quenched approximation, at fixed lattice spacing and cou...