CERN Accelerating science

Preprint
Report number	E1-2004-137 ; JINR-E1-2004-137
Title	Observation of $S=+1$ Narrow Resonances in the System $pK^0_s$ from $p+\rm {C_3H_8}$ Collision at 10 GeV/$c$
Author(s)	Aslanyan, P Zh ; Emelyanenko, V N ; Rikhvitskaya, G G
Affiliation	(Veksler and Baldin Laboratory of High Energies, Dubna) ; (Yerevan State University, Armenia)
Publication	2004
Imprint	3 Sep 2004
Number of pages	7
Subject category	Particle Physics - Experiment
Abstract	Experimental data from a 2 m propane bubble chamber have been analyzed to search for an exotic baryon state, the $\Theta^+$ baryon, in the $pK^0_s$ decay mode for the reaction $p+{\rm C_3H_8}$ at 10 GeV/$c$. The $pK^0_s$ invariant mass spectrum shows resonant structures with $M_{p K_s^0}=1540\pm 8$, $1613\pm10$, $1821\pm11$ MeV/$c^2$ and $\Gamma_{p K_s^0}= 9.2\pm1.8$, $16.1\pm4.1$, $28.0\pm9.4$ MeV/$c^2$. The statistical significance of these peaks has been estimated as $5.5$, $4.8$ and $5.0$ s.d., respectively. There are also small peaks in mass regions of 1487 (3.0 s.d.), 1690 (3.6 s.d.) and 1980 (3.0 s.d.) MeV/$c^2$.
Submitted by	[email protected]