The CHAOS Collaboration at TRIUMF has measured differential cross sections for π±p elastic at incident pion kinetic energies of 19.9, 25.8, 32.0, 37.1, 43.3, 57.0, and 67.0 MeV. The data analysis at the five lowest energies has been completed at the University of Tübingen. In order to measure at forward angles, in the Coulomb-Nuclear Interference region, the CHAOS detector was modified from its standard configuration with a specially developed range telescope. μ±p scattering at forward angles was also measured simultaneously, and used for validation of acceptance simulations.
AbstractWith analytical representation for the pp scattering amplitudes introduced and tested at lower energies, a description of high precision is given of the $$d\sigma /dt$$
d
σ
/
d
t
data at $$\sqrt{s}= 13$$
s
=
13
TeV for all values of the momentum transfer, with explicit identification of the real and imaginary parts. In both t and b coordinates the amplitudes have terms identified as of non-perturbative and perturbative nature, with distinction of their influences in forward and large |t| ranges and in central and peripheral regions respectively. In the forward range, the role of the Coulomb-nuclear interference phase is investigated. The energy dependence of the parameters of the amplitudes are reviewed and updated, revealing a possible emergence of a peculiar behavior of elastic and inelastic profiles in b-space for central collisions, which seems to be enhanced quickly at higher energies. Some other models are also briefly discussed in comparison, including the above mentioned behavior in b-space.
Measurement of Analyzing Power for Proton-Carbon Elastic Scattering in the Coulomb-Nuclear Interference Region with a22−GeV/cPolarized Proton Beam
