Measurement of the transverse spin dependence of the pp total cross section in the 1–3 GeV/c region

Abstract

The pp total cross section difference between pure transverse spin states was measured in the laboratory momentum range l-3 GeV/c. Significant differences were found and these differences show striking energy dependence. This structure is in disagreement with the predictions of simple exchange models.

Hidden dibaryons in one- and two-pion production in NN collisions

“…In that time, the first experimental indications appeared for existence of the number of dibaryon states. In particular, in elastic scattering of polarized protons p + p, the signals of a whole series of isovector dibaryons in 1 D 2 , 3 F 3 , 1 G 4 , etc., partial waves were found [8,9,10] (see also later experimental works [11,12,13]). Besides that, rather convincing though indirect indications for an isoscalar dibaryon with quantum numbers I(J P ) = 0(3 + ) were found in measurements of the outgoing proton polarisation in the deuteron photodisintegration process γd → pn at energies E γ ≃ 400-600 MeV [14,15,16].…”

“…However, a number of more sensitive polarization characteristics were not reproduced within the framework of conventional meson-exchange models [32,33]. So, it was claimed [24] that excitation of the intermediate dibaryon resonances found in elastic pp scattering [5,9,10] should be taken into account in the NN → dπ process as well.…”

“…Ψ d is given by Eqs. ( 9)- (10). There are four independent helicity amplitudes in πd elastic scattering: 7…”