Rotational covariance and light-front current matrix elements
نویسندگان
چکیده
منابع مشابه
Rotational covariance and light-front current matrix elements.
Light-front current matrix elements for elastic scattering from hadrons with spin 1 or greater must satisfy a nontrivial constraint associated with the requirement of rotational covariance for the current operator. Using a model ρ meson as a prototype for hadronic quark models, this constraint and its implications are studied at both low and high momentum transfers. In the kinematic region appr...
متن کاملBaryon current matrix elements in a light-front framework.
Current matrix elements and observables for electroand photo-excitation of baryons from the nucleon are studied in a light-front framework. Relativistic effects are estimated by comparison to a nonrelativistic model, where we use simple basis states to represent the baryon wavefunctions. Sizeable relativistic effects are found for certain transitions, for example, to radial excitations such as ...
متن کاملOff-forward Matrix Elements in Light-Front Hamiltonian QCD
We investigate the off-forward matrix element of the light cone vector operator for a dressed quark state in light-front Hamiltonian perturbation theory. We obtain the corresponding splitting functions in a straightforward way. We show that the end point singularity is canceled by the contribution from the normalization of state. Considering mixing with the gluon operator, we verify the helicit...
متن کاملAxial-Current Matrix Elements in Light Nuclei from Lattice QCD
I present results from the first lattice QCD calculations of axial-current matrix elements in light nuclei, performed by the NPLQCD collaboration. Precision calculations of these matrix elements, and the subsequent extraction of multi-nucleon axial-current operators, are essential in refining theoretical predictions of the proton-proton fusion cross section, neutrino-nucleus cross sections and ...
متن کاملLight Hadron Weak Matrix Elements
The kaon bag parameter BK , which is required for constraining the CP violation parameter in the Cabibbo-Kobayashi-Maskawa matrix from experiment, has been successfully calculated with the Kogut-Susskind(KS) quark action, taking advantage of its UA(1) chiral symmetry[1]. A recent systematic calculation of BK with high statistics[2], however, reveals that the systematic uncertainties in the pert...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Physical Review D
سال: 1994
ISSN: 0556-2821
DOI: 10.1103/physrevd.49.1500