Topic
Spin-½
About: Spin-½ is a research topic. Over the lifetime, 40423 publications have been published within this topic receiving 796639 citations.
Papers published on a yearly basis
Papers
More filters
TL;DR: In this paper, the first-order density matrix is obtained for the state corresponding to a spin projection of a general different orbitals for different spins single determinental function, and the spin density and the charge density matrices are found to have the same natural orbitals in the projected state as in the unprojected state.
Abstract: The first‐order density matrix is obtained for the state corresponding to a spin projection of a general different orbitals for different spins single determinental function. Explicit expressions are given for the natural orbitals and occupation numbers in terms of parameters characteristic of the unprojected state. The spin density and the charge density matrices are found to have the same natural orbitals in the projected state as in the unprojected state. A number of special and limiting cases are considered, including that of slightly different orbitals for different spins.
145 citations
145 citations
01 Apr 2000
TL;DR: For heavy-light mesons, a relativistic symmetry that suppresses splittings in hadrons is identified and it is argued that the dynamics necessary for this symmetry are possible in QCD.
Abstract: Experimental data indicate small spin-orbit splittings in hadrons. For heavy-light mesons we identify a relativistic symmetry that suppresses these splittings. We suggest an experimental test in electron-positron annihilation. Furthermore, we argue that the dynamics necessary for this symmetry are possible in QCD.
145 citations
Metz1
TL;DR: In this article, the authors considered the adiabatic evolution of the Dirac equation in order to compute its Berry curvature in momentum space and found that the position operator acquires an anomalous contribution due to the non-Abelian Berry gauge connection making the quantum mechanical algebra noncommutative.
145 citations
TL;DR: In this paper, the triplet spin state is discussed under the following assumptions about the nuclear forces: (1) the forces are conservative, (2) they allow time-reversal, i.e., the reciprocity law is valid, and (3) the spin vectors of the neutron and proton enter in a symmetrical way, so that the total spin of the system is preserved during the collision.
Abstract: Neutron-proton scattering in the triplet spin state is discussed under the following assumptions about the nuclear forces: (1) the forces are conservative, (2) they allow time-reversal, i.e., the reciprocity law is valid, (3) the spin vectors of the neutron and proton enter in a symmetrical way, so that the total spin of of the system is preserved during the collision, and (4) the forces have a finite range. We do not assume that the forces can be derived from a potential function (i.e., that they are velocity-independent).General expressions are given for the scattering matrix and for the differential cross section. The matrix elements of the scattering matrix are expressed in terms of the minimum numbers of real, independent parameters. The energy dependence of these parameters near zero energy can be predicted uniquely on the basis of assumptions (1) to (4) above.
145 citations