K+total cross sections onC12

Abstract

The total cross sections for K+ mesons on carbon and deuterium nuclei have been measured at eleven momenta in the range 450-740 MeV/c. The experimental technique was of the standard transmission type. The K+ meson is the least strongly interacting of available hadronic probes, with a long mean free path in nuclear matter. At low incident momentum the K+K interaction is dominated by the Szz phase shift and varies slowly with energy. These characteristics make the K+ an ideal tool for probing the nuclear volume to reveal nuclear medium effects. Measurements of the ratio of the total cross sections, per nucleon, of K+-C to K+-d have been suggested as a way to reveal effects of the nuclear medium. The total cross section ratios are found to lie significantly above those predicted by the usual nuclear medium corrections. This suggests that novel phenomena are taking place within the nucleus. Several models which incorporate such phenomena are discussed, including nucleon swelling, " mass rescaling, nuclear pions, and relativistic efFects.

Microscopic analysis ofK+-nucleus elastic scattering based onK+-nucleon phase shifts

“…Total cross sections for K + -nucleus have been extracted from transmission experiments [2,3,4]. Such data are complementary to the differential cross section data and exhibit often larger differences among the full-folding and tρ results, even though the same KN effective interaction is used.…”

K+-nucleon amplitudes in the medium below 800 MeV/c

“…(3) (lower part) the dependence on the beam momentum is reproduced at the level of 2-3% as is also the absolute scale of the cross sections. Including corrections due to Pauli correlations made no difference in the case of 6 Li, presumably because of the low density of this nucleus. Fig.…”

“…Comparing total cross sections of K + on 6 Li with three times the cross sections on deuteron, it was found that within 2% there are no indications for medium effects in the results for 6 Li, where the average density is about half of the average density for other nuclei [10,11]. Consequently in what follows we use 6 Li as a reference. Ratios between experimental and calculated reaction (left panels) and total cross sections (right panels) of K + on C, Si Ans Ca.…”

“…The same set of transmission measurements was later reanalysed to determine not only total cross sections but also reaction cross sections, that are less dependent on applied corrections [9]. Comparing total cross sections of K + on 6 Li with three times the cross sections on deuteron, it was found that within 2% there are no indications for medium effects in the results for 6 Li, where the average density is about half of the average density for other nuclei [10,11]. Consequently in what follows we use 6 Li as a reference.…”

“…For K + interaction with nucleons in the momentum range of 400-800 MeV/c the relevant energies in the medium are lower than the cm beam energy by up to 30 MeV. Total cross sections for K + on D, 6 Li, C, Si and Ca were measured in the early 1990s at four momenta below 800 MeV/c [5][6][7][8] . The same set of transmission measurements was later reanalysed to determine not only total cross sections but also reaction cross sections, that are less dependent on applied corrections [9].…”