0 Measurements of the Σ 0 c and Σ + + c Mass Splittings

Isospin Splittings of Baryons

We discuss the isospin-breaking mass differences among baryons, with particular attention in the charm sector to the Σ c − Σ c , Σ c − Σ c , and Ξ c − Ξ c splittings. Simple potential models cannot accommodate the trend of the available data on charm baryons. More precise measurements would offer the possibility of testing how well potential models describe the non-perturbative limit of QCD. A ...

Measurement of the Σ π photoproduction line shapes near the Λ ( 1405 )

The reaction γ + p → K + + Σ + π was used to determine the invariant mass distributions or " line shapes " of the Σ + π − , Σ − π + and Σ 0 π 0 final states, from threshold at 1328 MeV/c 2 through the mass range of the Λ(1405) and the Λ(1520). The measurements were made with the CLAS system at Jefferson Lab using tagged real photons, for center-of-mass energies 1.95 < W < 2.85 GeV. The three ma...

Lambda Polarization in Polarized Proton-Proton Collisions at RHIC

We discuss Lambda polarization in semi-inclusive proton-proton collisions, with one of the protons longitudinally polarized. The hyperfine interaction responsible for the ∆-N and Σ-Λ mass splittings gives rise to flavor asymmetric fragmentation functions and to sizable polarized non-strange fragmentation functions. We predict large positive Lambda polarization in polarized proton-proton collisi...

δ-Double Derivations on C*-Algebras

ar X iv : h ep - p h / 04 03 15 3 v 5 2 3 A ug 2 00 4 T - Dependent Dyson - Schwinger Equation In IR Regime Of QCD : The Critical Point

The quark mass function Σ(p) in QCD is revisited, using a gluon propagator in the form 1/(k 2 + m 2 g) plus 2µ 2 /(k 2 + m 2 g) 2 , where the second (IR) term gives linear confinement for m g = 0 in the instantaneous limit, µ being another scale. To find Σ(p) we propose a new (differential) form of the Dyson-Schwinger Equation (DSE) for Σ(p), based on an infinitesimal subtractive Renormalizatio...