Pion-induced production of Λ(1520) hyperons on nuclei near threshold

Abstract

We study the pion-induced inclusive Λ(1520) hyperon production from nuclei near threshold within a nuclear spectral function approach accounting for incoherent primary π − mesonproton π − p → K 0 Λ(1520) production processes. We calculate the absolute differential and total cross sections for the production of Λ(1520) hyperons off carbon and tungsten nuclei at laboratory angles of 0 • -10 • , 10 • -45 • and 45 • -85 • by π − mesons with momentum of 1.7 GeV/c as well as their relative (transparency ratio) differential and integral yields from these nuclei within four scenarios for their total in-medium width. We demonstrate that these absolute observables, contrary to the relative ones, reveal some sensitivity to the Λ(1520) in-medium width. Therefore, their measurement in a dedicated experiment at the GSI pion beam facility will allow to shed light on this width. 1) We can neglect the processes π − N → KΛ(1520)π with one pion in the final state at the incident pion momentum of 1.7 GeV/c, because they are energetically suppressed due to the fact that this momentum is less than their production threshold momentum of 1.98 GeV/c in vacuum π − N collisions. Moreover, taking into account the results of the study [21] of pion-induced φ meson production on 12 C and 184 W nuclei at beam momentum of 1.7 GeV/c, we ignore in the present work by analogy with [21] the secondary pion-nucleon πN → KΛ(1520) production processes.2) Determining the strength of the Λ(1520) production cross sections in π − A collisions near threshold (cf. [21]).