We consider the pion structure in the region of low and moderately high momentum transfers: at low Q 2 , the pion is treated as a composite system of constituent quarks; at moderately high momentum transfers, Q 2 = 10 ÷ 25 GeV 2 , the pion form factor is calculated within perturbative QCD taking into account one–gluon hard exchange. Using the data on pion form factor at Q 2 < 3 GeV 2 and pion a...

We obtain reliable ππ scattering amplitudes consistent with experimental data, both at low and high energies, and fulfilling appropriate analyticity properties. We do this by first fitting experimental low energy (s ≤ 1.42GeV) phase shifts and inelasticities with expressions that incorporate analyticity and unitarity. In particular, for the S wave with isospin 0, we discuss in detail several se...

The pion, and specifically its charge form factor, is of key interest in the study of the quark-gluon structure of hadrons. This is exemplified by the many calculations that treat the pion as one of their prime examples. One of the reasons is that the valence structure of the pion, being 〈qq̄〉, is relatively simple. Hence it is expected that the value of the four-momentum transfer squared Q, dow...

Ion recombination is approximately corrected for in the Task Group 51 protocol by Pion, which is calculated by a two-voltage measurement. This measurement approach may be a poor estimate of the true recombination, particularly if Pion is large (greater than 1.05). Concern exists that Pion in high-dose-per-pulse beams, such as flattening filter free (FFF) beams, may be unacceptably high, renderi...

We point out that, in analogy with spin waves in antiferromagnets, all parameters describing the real-time propagation of soft pions at temperatures below the QCD chiral phase transition can be expressed in terms of static correlators. This allows, in principle, the determination of the soft pion dispersion relation on the lattice. Using scaling and universality arguments, we determine the crit...

Current work on pion production in high-energy nucleus-nucleus collisions is re­ viewed. The majority of existing data are of the inclusive variety in which a single final state pion is detected. Experimental data are compared and their possible con­ tributions to obtaining new information on nuclear structure is discussed. Various models which attempt to explain the observed singlc-inclusive-p...