Abstract
The production of Xi (1321)^{-} and overline{Xi }(1321)^{+} hyperons in inelastic p+p interactions is studied in a fixed target experiment at a beam momentum of 158 hbox {Ge}hbox {V}!/!c. Double differential distributions in rapidity {y} and transverse momentum p_{T} are obtained from a sample of 33M inelastic events. They allow to extrapolate the spectra to full phase space and to determine the mean multiplicity of both {Xi }{^-} and overline{Xi }{^+} . The rapidity and transverse momentum spectra are compared to transport model predictions. The {Xi }{^-} mean multiplicity in inelastic p+p interactions at 158 hbox {Ge}hbox {V}!/!c is used to quantify the strangeness enhancement in A+A collisions at the same centre-of-mass energy per nucleon pair.
Highlights
Hyperons are made up of one or more strange valence quarks
At the same time rather impressive efforts have been invested into studies of hyperon production in nucleus–nucleus interactions, because strangeness carrying particles are expected to have different characteristics when produced in hadron–hadron and nucleus-nucleus collisions
Measurements of − and + spectra in inelastic p+p interactions at 158 GeV/c were performed by the NA61/SHINE experiment at the CERN SPS
Summary
Hyperons are made up of one or more strange valence quarks. In p+p interactions the initial state has no constituent strange quarks. At the same time rather impressive efforts have been invested into studies of hyperon production in nucleus–nucleus interactions, because strangeness carrying particles are expected to have different characteristics when produced in hadron–hadron and nucleus-nucleus collisions. A number of complex nuclear effects enter here which are difficult to control quantitatively This is why NA61/SHINE has embarked upon a systematic study of hyperon production in an experimental programme which covers hadron–proton, hadron–nucleus, and nucleus– nucleus collisions [2,3,4,5]. Interactions in the target are selected with the trigger system by requiring an incoming beam proton and no signal from S4, a small 2 cm diameter scintillation counter placed on the beam trajectory between the two vertex magnets (see Fig. 1) This minimum bias trigger fires, if no charged particle is detected on the beam trajectory downstream of the target
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
