相关论文: Classifying Reported and "Missing" Resonances Acco…
Relativistic resonances and decaying states are described by representations of Poincar\'e transformations, similar to Wigner's definition of stable particles. To associate decaying state vectors to resonance poles of the $S$-matrix, the…
We demonstrate that a highly excited quantum electromagnetic mode strongly interacting with a single qubit exhibits several distinct resonances in addition to the Bloch-Siegert resonance condition that arises in the interaction with…
The Rigged Hilbert Space (RHS) theory of resonance scattering and decay is reviewed and contrasted with the standard Hilbert space (HS) theory of quantum mechanics. The main difference is in the choice of boundary conditions. Whereas the…
The pole positions of the various baryon resonances are known to reveal well-pronounced clustering, so-called Hoehler clusters. For nonstrange baryons the Hoehler clusters are shown to be identical to Lorentz multiplets of the type…
Quantum resonances in the kicked rotor are characterized by a dramatically increased energy absorption rate, in stark contrast to the momentum localization generally observed. These resonances occur when the scaled Planck's constant…
The first part of the paper reviews applications of 2-spinor methods to relativistic qubits (analogies between tetrads in Minkowski space and 2-qubit states, qubits defined by means of null directions and their role for elimination of the…
I review theory and phenomenology of (K/2,K/2)*[(1/2,0)+(0,1/2)] states. First I make the case that the observed nucleon and Delta (1232) excitations (up to Delta(1600)) are exhausted by unconstrained (K/2,K/2)*[(1/2,0)+(0,1/2)] states with…
We extend the nonrelativistic QCD framework to explore the nature of the newly discovered di-$J/\psi$ resonances. Assuming them as either molecule-like states or tetraquarks, we calculated their hadroproduction cross sections at the LHC. We…
After a brief review of the celebrated 1941 paper of Rarita and Schwinger on the theory of particles with half-integral spins, we present an {\em ab initio} construct of the representation space relevant for the description of spin-3/2…
The structure of the reported excitation spectra of the light unflavored baryons is described in terms of multi-spin valued Lorentz group representations of the so called Rarita-Schwinger (RS) type (K/2, K/2)* [(1/ 2,0)+ (0,1/2)] with…
A consistent phenomenology of the interaction of particles of arbitrary spin requires covariant spinors, field operators, propagators and model interactions. Guided by an approach originally proposed by Weinberg, we construct from group…
We investigate the status of the lower spin-1/2 companions to spin-3/2 within the four-vector spinor, $\psi_\mu$. According to its reducibility, $\psi_\mu\longrightarrow \left[(1/2,1)\oplus (1,1/2)\right]\oplus [(1/2,0)\oplus (0,1/2)]$ this…
A well pronounced spin--grouping of baryon resonances to O(4) partial waves is found in baryon spectra and shown to be well interpreted in terms of Lorentz group representations of the type (1/2 +l', 1/2 +l')* [(1/2, 0)+(0,1/2)] with l'…
Einstein's photo-electric effect allows us to regard electromagnetic waves as massless particles. Then, how is the photon helicity translated into the electric and magnetic fields perpendicular to the direction of propagation? This is an…
Spinor-valued one-forms (Rarita-Schwinger fields) are normally used in the context of supergravity, where they describe spin 3/2 particles (gravitinos). Indeed, when decomposed into irreducible representations of the Lorentz group such a…
The spectrum of a quantum system has in general bound, scattering and resonant parts. The Hilbert space includes only the bound and scattering spectra, and discards the resonances. One must therefore enlarge the Hilbert space to a rigged…
We show that higher order differential equations and matrix spinor calculus are completely avoidable in the description of pure high spin-$j$ Weinberg-Joos states, $(j,0)\oplus (0,j)$. The case is made on the example of…
We describe relativistic particles with spin as points moving in phase space $X=T^* R^{1,3}\times C^2_L\times C^2_R$, where $T^* R^{1,3}=R^{1,3}\times R^{1,3}$ is the space of coordinates and momenta, and $C^2_L$ and $C^2_R$ are the spaces…
The relativistic three-body problem is approached via the extension of the SL(2,C) group to the Sp(4,C) one. In terms of Sp(4,C) spinors, a Dirac-like equation with three-body kinematics is composed. After introducing the linear in…
I make the case that the nucleon excitations do not exist as isolated higher spin states but are fully absorbed by (K/2,K/2)*[(1/2,0)+ (0,1/2)] multiplets taking their origin from the rotational and vibrational excitations of an underlying…