Double Resonance in Dalitz Plot of M(pLambda)-M(KLambda) in DISTO Data on p+p rightarrow p+Lambda+K+ at 2.85 GeV

TL;DR

This paper reports a double resonance phenomenon in p+p collisions at 2.85 GeV, revealing a peak at 2265 MeV/c2 in pLambda and a broad bump at 1700 MeV/c2 in K+Lambda, suggesting complex resonance interactions.

Contribution

It uncovers a novel double resonance structure in the Dalitz plot of p+p collisions, linking it to nucleon resonances and final-state interactions, not previously observed in this context.

Findings

Identification of a peak at M(pLambda) = 2265 MeV/c2

Observation of a broad bump at M(K+ Lambda) ~ 1700 MeV/c2

Double resonance zone XY(2265, 1700) not accessible at higher energies

Abstract

The X(2265) resonance was previously observed in DISTO data of p+p rightarrow p+Lambda+K+ at 2.85 GeV on an attempt of searching for the kaonic nuclear state K-pp rightarrow p + Lambda. In the present paper we report an additional finding, namely, a double resonance type phenomena, not only with a peak at M(pLambda) = 2265 MeV/c2 but also a broad bump at M(K+ Lambda) ~ 1700 MeV/c2. This "double-resonance" zone is expressed as XY(2265, 1700). The latter bump may result from nearby nucleon resonances, typically N*(1710), as well as by attractive K - Lambda final-state interaction. We point out that this double resonance XY(2265, 1700) as seen in DISTO at 2.85 GeV cannot be populated kinematically in a HADES experiment at 3.5 GeV.