Formation of a narrow baryon resonance with positive strangeness in K + collisions with Xe nuclei

Abstract

The data on the charge-exchange reaction K + Xe → K 0 pXe ′ , obtained with the bubble chamber DIANA, are reanalyzed using increased statistics and updated

Observation of a narrow baryon resonance with positive strangeness formed inK+Xe collisions

“…Using the ratio between the numbers of resonant and nonresonant charge-exchange events in the peak region, the intrinsic width of this baryon resonance has been determined as ( + ) = 0.34 ± 0.10 MeV. The results reported in this paper confirm our earlier observations based on part of the present statistics of the charge-exchange reaction K + Xe → K 0 pXe [5,7,8].…”

“…This estimate of the + intrinsic width has been derived assuming that the bulk of produced + baryons decay upon leaving the nucleus. The value of obtained in this analysis is consistent with our earlier estimates [7,8], and does not violate the upper limits set by BELLE [14] and by the E19 experiment at J-PARC [32].…”

“…Subsequently, both experiments were able to confirm their initial observations [6][7][8]. Moreover, increasing the statistics of the charge-exchange reaction allowed DIANA to directly estimate the + intrinsic width: 0.4 ± 0.1 MeV [7,8]. More recently, observation of a narrow peak near 1.54 GeV in the missing mass of the K 0 S meson in the reaction γp → K 0 S K 0 L p was reported by a group from the CLAS Collaboration [9].…”

“…Subsequently, both experiments were able to confirm their initial observations [6][7][8]. Moreover, increasing the statistics of the charge-exchange reaction allowed DIANA to directly estimate the + intrinsic width: 0.4 ± 0.1 MeV [7,8].…”

“…2(c) and 2(d). This selection has already been used in our previous papers [5,7,8], and was found to produce no artificial structures in the m(pK 0 ) spectrum by an independent theoretical analysis [31]. The simulation predicts that this selection retains 77% of all rescattering-free events.…”