575 research outputs found
B-Mesons on the Transverse Lattice
We present results from a first study of -mesons that is based on a
transverse lattice formulation of light-front QCD. The shape of the Isgur-Wise
form factor is in very good agreement with experimental data. However, the
calculations yield rather large values for and compared
to contemporary calculations based on other techniques.Comment: invited talk given at CSSM workshop on `Lattice Hadron Physics',
Cairns, July 2001 and at ECT* workshop on `Light-cone Physics: Particles and
String', Trento, Sept. 200
Quark Correlations and Single Spin Asymmetries
We analyze the Sivers asymmetry in light-cone gauge. The average transverse
momentum of the quark distribution is related to the correlation between the
quark distribution and the transverse component of the gauge field at . We then use finiteness conditions for the light-cone Hamiltonian to
relate the transverse gauge field at to the color density
integrated over . This result allows us to relate the average transverse
momentum of the active quark to color charge correlations in the transverse
plane.Comment: 8 pages, 1 figur
Impact Parameter Space Interpretation for Generalized Parton Distributions
The Fourier transform of generalized parton distribution functions at xi=0
describes the distribution of partons in the transverse plane. The physical
significance of these impact parameter dependent parton distribution functions
is discussed. In particular, it is shown that they satisfy positivity
constraints which justify their physical interpretation as a probability
density. The generalized parton distribution H is related to the impact
parameter distribution of unpolarized quarks for an unpolarized nucleon,
H-tilde is related to the distribution of longitudinally polarized quarks in a
longitudinally polarized nucleon, and is related to the distortion of the
unpolarized quark distribution in the transverse plane when the nucleon has
transverse polarization.Comment: addtl. corrections, 34 page
Finiteness Conditions for Light-Front Hamiltonians
In the context of simple models, it is shown that demanding finiteness for
physical masses with respect to a longitudinal cutoff, can be used to fix the
ambiguity in the renormalization of fermions masses in the Hamiltonian
light-front formulation. Difficulties that arise in applications of finiteness
conditions to discrete light-cone quantization are discussed.Comment: REVTEX, 9 page
A 3+1 Dimensional Light-Front Model with Spontaneous Breaking of Chiral Symmetry
We investigate a 3+1 dimensional toy model that exhibits spontaneous
breakdown of chiral symmetry, both in a light-front (LF) Hamiltonian and in a
Euclidean Schwinger-Dyson (SD) formulation. We show that both formulations are
completely equivalent --- provided the renormalization is properly done. For
the model considered, this means that if one uses the same transverse momentum
cutoff on the SD and LF formulations then the vertex mass in the LF calculation
must be taken to be the same as the current quark mass in the SD calculation.
The kinetic mass term in the LF calculation is renormalized non-trivially,
which is eventually responsible for the mass generation of the physical fermion
of the model.Comment: 6 pages, REVTE
QCD on a transverse lattice
We present results from a transverse lattice study of low lying mesons.
Special emphasis is put on the issue of Lorentz invariant energy-momentum
dispersion relations for these mesons. The light-cone wave function for the
obtained in this framework is very close to its asymptotic shape.Comment: 10 pages, sprocl.sty, invited talk given at 5th International
Workshop on Particle Phyiscs Phenomenology, Chi-Pen, Taitung, Taiwan, 8-11
Nov 200
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