We use the matrix product state formalism to construct stationary scattering states of elementary excitations in generic one-dimensional quantum lattice systems. Our method is applied to the spin-1 Heisenberg antiferromagnet, for which we calculate the full magnon-magnon S matrix for arbitrary momenta and spin, the two-particle contribution to the spectral function, and higher order corrections...

A 6-component “wave function” (not field, but S-matrix interpretable) for a massive spin-1 particle parallels the Dirac “chiralitydoubled” 4-component wave function for a spin-1/2 particle, by pairing two wave functions for same spin but opposite “handedness”. The correlated “opposite-parity” pair of complex 3-vectors defines a fluctuating spin-correlated lightlike “internal velocity” as well a...

In this paper the connection between the dipole moment tensor D and the spin four-tensor S is formulated in the form of the generalized UhlenbeckGoudsmit hypothesis, D = gSS . It is also found that the spin four-tensor S can be decomposed into two 4-vectors, the usual “space-space” intrinsic angular momentum S, which will be called ‘magnetic’ spin (mspin), and a new one, the “time-space” intrin...

Dark matter is believed to comprise approximately eighty-three percent of the matter in the universe, yet little is known about how it fits into our picture of the elementary particles that make up the world around us. There are now many great efforts underway to try and detect dark matter and probe the nature of its relation to the Standard Model of particle physics. In this work we investigat...

Are black holes elementary particles? Are they fermions or bosons? We investigate the remarkable possibility that quantum black holes are the smallest and heaviest elementary particles. We are able to construct various fundamental quantum black holes: the spin-0, spin-1/2, spin-1, and the Planckcharge cases, using the results in general relativity. Quantum black holes in the neighborhood of the...

A unified description of spacetime and matter is proposed by using a single irreducible representation of SO(10) Super-Poincaré algebra(SO(10)SPA). All (observed) elementary particles except the graviton are the (massless) eigenstates of SO10)SPA composed of fundamental Nambu-Goldstone fermions with spin 1/2, superons associating with the spontaneous breakdown of the supertranslation of the spa...

HEN A STRANGER, hearing that I am a physicist, asks me in what area of physics I work, I generally reply that I work on the theory of elementary particles. Giving this answer always makes me nervous. Suppose that the stranger should ask, “What is an elementary particle?” I would have to admit that no one really knows. Let me declare first of all that there is no difficulty in saying what is mea...

To know the properties of a particle or a wave, one should measure how its energy changes with its momentum. The relation between them is called the dispersion relation, which encodes essential information of the kinetics. In a magnet, the wave motion of atomic spins serves as an elementary excitation, called a spin wave, and behaves like a fictitious particle. Although the dispersion relation ...

In a geometric approach to special relativity it is found that the spin four-tensor S can be decomposed into two 4-vectors, the usual “space-space” intrinsic angular momentum S and a new one, the “time-space” intrinsic angular momentum Z, which are both equally well physical quantities. It is also shown that an electric dipole moment (EDM) of a fundamental particle, as a four-dimensional geomet...

First we argue in an informal, qualitative way that it is natural to enlarge space-time to five dimensions to be able to solve the problem of elementary particle masses. Several criteria are developed for the success of this program. Extending the Poincaré group to the group C of all angle-preserving transformations of space-time is one such scheme which satisfies these criteria. Then we show t...