Related papers: How High is High x?
Physics perspectives are shown for future experiments in electron or positron scattering on nucleons, towards a deep and comprehensive understanding of the angular momentum structure of the nucleon in the context of Quantum Chromodynamics.…
Top-antitop pairs produced at hadron colliders are largely unpolarized, but their spins are highly correlated. The structure of these correlations varies significantly over top production phase space, allowing very detailed tests of the…
Bound q\bar q -systems are considered in the framework of three different versions of the 3-dimensional reduction of the Bethe-Salpeter equation, all having the correct one-body limit when one of the constituent quark masses tends to…
It is shown that hyperon beta decay data can be well accommodated within the framework of Cabbibo's SU(3) symmetric description if one allows for a small SU(3) symmetry breaking proportional to the mass difference between strange and…
We discuss the nucleon to higher-spin $N$- and $\Delta$-resonance transitions by pions and photons. The higher-spin baryons are described by Rarita-Schwinger fields and, as we argue, this imposes a stringent consistency requirement on the…
We develop a technique to directly study spinons (emergent spin S = 1/2 particles) in quantum spin models in any number of dimensions. The size of a spinon wave packet and of a bound pair (a triplon) are defined in terms of wave-function…
In contrast to the canonically conjugate variates $q$,$p$ representing the position and momentum of a particle in the phase space distributions, the three Cartesian components, $J_{x}$,$J_{y}$, $J_{z}$ of a spin-$j$ system constitute the…
ew-electron systems confined in quasi one-dimensional quantum dots are studied by the configuration interaction approach. We consider the parity symmetry of states forming Wigner molecules in large quantum dots and find that for the…
A tight binding model is introduced to describe the strong interaction limit of excitonic ordering. At stoichiometry, the model reduces in the strong coupling limit to a pseudo-spin model with approximate U(4) symmetry. Excitonic order…
The identification of the correct model for physics beyond the Standard Model requires the determination of the spin of new particles. We investigate to which extent the spin of a new particle $X$ can be identified in scenarios where it…
The physics of interacting integer-spin chains has been a topic of intense theoretical interest, particularly in the context of symmetry-protected topological phases. However, there has not been a controllable model system to study this…
We determine baryon-baryon bound states in 3+1 dimensional ${\rm SU}(3)$ lattice QCD with two flavors, $4\times 4$ spin matrices, and in an imaginary time formulation. For small hopping parameter, $\kappa>0$, and large glueball mass (strong…
We present a factorization formula for valence quark distributions in a hadron in x-->1 limit. For the example of pion, we arrive at the form of factorization by analyzing momentum flow in the leading and high-order Feynman diagrams. The…
The structure of a bound state of several Dirac particles is discussed. Relying on solid mathematical arguments of the Wigner-Racah algebra, it is proved the a non-negligible number of configurations is required for a description of this…
We discuss a model for the relativistic bound states of 3-quark baryons based on confining quantum chromoynamics (QCD) with general Yang-Mills symmetry. The model postulates that 3-quark states are formed by consecutive 2-body collisions.…
Postulated by Pauli to explain the electronic structure of atoms and molecules, the exclusion principle establishes an upper bound of 1 for the fermionic natural occupation numbers $\{n_i\}$. A recent analysis of the pure…
Previous measurements with a single trapped proton or antiproton detected spin resonance from the increased scatter of frequency measurements caused by many spin flips. Here a measured correlation confirms that individual spin transitions…
The proton spin puzzle denotes the challenge of describing the proton's spin in terms of the angular momenta of the quarks and gluons which comprise it. These quarks and gluons carry a fraction $x$ of the proton's momentum. Contributions…
The compounds A$_2$Cu$_3$O(SO$_4$)$_3$ (A=Na, K) are characterized by copper hexamers which are weakly coupled to realize antiferromagnetic order below TN=3 K. They constitute novel quantum spin systems with S=1 triplet ground-states. We…
As the heaviest known fundamental particle, the top quark has taken a central role in the study of fundamental interactions. The top quark mass is a fundamental parameter of the standard model which places constraints on the Higgs boson…