Related papers: Quark spin coupling in baryons - revisited
We generalize spin-rotation coupling to compound spin systems. In the case of muons bound to nuclei in a storage ring the decay process acquires a modulation. Typical frequencies for $Z/A\sim 1/2$ are $\sim 3\times 10^6$Hz, a factor 10…
Including the meson-baryon (5 quark) intermediate states in a lattice simulation is challenging. However, it is important in order to obtain the correct energy eigenstates and to relate them to scattering phase shifts. Recent results for…
Interactions between hard partons and the quark-gluon plasma range from frequent soft interactions to rare hard scatterings. The larger number of soft interactions makes possible an effective stochastic description of parton-plasma…
Gluons are strong interaction gauge fields which interact between quarks, i.e. constituents of baryons and mesons. Interaction of matters is phenomenologically described by gauge theory of strong, electromagnetic, weak and gravitational…
Deep inelastic structure functions for the nucleon are obtained in a constituent quark model on the light cone. In the Bjorken limit the parton model is derived. Structure functions from the hadronic tensor at the scale $\mu \sim 0.25$ GeV…
Spin-polarons are obtained using an Ising-like exchange model consisting of double and super-exchange interactions in low dimensional systems. At zero temperature, a new phase separation between small magnetic polarons, one conduction…
Making use of numerous resonances discovered by the Crystal Barrel Collaboration we discuss some possible relations between the baryon and meson spectra of resonances composed of the light non-strange quarks. Our goal is to indicate new…
We present an unquenched quark model for baryons in which the effects of the quark-antiquark pairs (up, down and strange) are taken into account in an explicit form via a microscopic, QCD-inspired, quark-antiquark creation mechanism. In the…
The analysis of some effects caused by the spin--dependent pomeron couplings is presented. It is shown that the structure of pomeron--proton and quark--pomeron couplings can be tested in future polarized experiments on elastic $pp$…
The spin and orbital angular momentum carried by different quark flavors in the nucleon are calculated in the SU(3) chiral quark model with symmetry-breaking. The model is extended to all octet and decuplet baryons. In this model, the…
We explore quark interactions mediated by new gauge bosons of masses in the 0.3 - 50 GeV range. A tight upper limit on the gauge coupling of light Z' bosons is imposed by the anomaly cancellation conditions in conjunction with collider…
We examine the effect of adding pion exchange between quarks and pion self-energy corrections to the Los Alamos Relativistic Quark model with a short distance cutoff of the Bethe form. The contributions to the nucleon and the Delta-baryon…
We investigate the processes leading to phase-space equilibration of parton distributions in nuclear interactions at collider energies. We derive a set of rate equations describing the chemical equilibration of gluons and quarks including…
The implications of the latest data pertaining to \bar u-\bar d asymmetry and the spin polarization functions on the contributions of singlet Goldstone boson \eta' within \chiCQM with configuration mixing for explaining the ``proton spin…
The pion structure function is investigated in a simple model, where pion and constituent quark fields are coupled through the simplest pseudoscalar coupling. The imaginary part of the forward gamma* pi-> gamma* pi scattering amplitude is…
We derive the pion-nucleon interaction in the framework of a new perturbative approach to QCD, based on the use of quark composites as fundamental variables. The composites with the quantum numbers of the nucleons are assumed as new…
Using a covariant and angular-momentum-conserved chiral transport model, which takes into account the spin-orbit interactions of chiral fermions in their scatterings via the side jumps, we study the quark spin polarization in quark matter.…
Lepton and quark asymmetries at Z boson peak are a powerful means to test the couplings of the Z boson to fermions. The measurements performed at LEP and SLC colliders are reviewed, and their impact on the determination of the electroweak…
Top quark pairs are produced with strongly correlated spins in the partonic reactions $q\bar{q}\to t\bar{t}$ and $gg\to t\bar{t}$. A complete description of these effects in terms of the spin density matrix of the $t\bar{t}$ system in…
New preliminary results on kaon and pion production in central 30AGeV Pb+Pb collisions are presented. The data are compared to data at lower and higher energies to examine the energy dependence of the kaon to pion ratios and the inverse…