The pp→K+nΣ+ reaction near threshold

Cross sections of the pp→K+Σ+n reaction close to threshold

“…The cross section for pp → K + Λp may have another systematical uncertainty of 10% due to a possible anisotropy of the kaon angular distribution. teractions with other data close to threshold [6,20,26]. In Fig.…”

“…The error bar contains also the absolute normalization uncertainty added in quadrature. The COSY-11 data [8] are shown as squares, the ANKE data point as a full diamond [6]. Cross section values reported by Sibirtsev et al [25] are shown as triangles.…”

“…For reactions (1.1) and (1.2) there are several measurements of total cross sections in the threshold region [1][2][3][4][5][6]. Direct observation of Λp FSI comes from the energy dependence of the total cross section in reaction (1.1).…”

“…Two measurements exist (three points in total) from different groups at COSY which vastly disagree with each other. COSY-11 [8] measured K + n coincidences while ANKE [6] relied on K + π + coincidences with the pion coming from the decay Σ + → π + n. The COSY-11 result indicates an enhancement of the cross section close to threshold, which might indicate a strong Σ + n FSI. In this work we use a different method to determine the pp → K + Σ + n cross section in the threshold region.…”

Upper limits for a narrow resonance in the reactionp+p→K++(Λp)

“…There were also exclusive measurements of the reaction pp ! K þ Ãp by the COSY-TOF Collaboration [15][16][17] and total cross section measurements by the COSY-11 [18] and COSY-ANKE Collaboration [19,20]. The first high-resolution measurement of pp !…”