Exotic narrow resonance searches in the systems $K_s^0 p$, $K_s^0 Λ$ and $Λp$ in pA-interactions at 10 GeV/c

Abstract

Experimental data from the 2m propane bubble chamber have been analyzed to search for an exotic baryon states, in the $K_s^0 p$, $K_s^0 Λ$ and $Λp$ decay mode for the reaction p+$C_3H_8$ at 10 GeV/c. The invariant mass spectrum $ΛK^0_s$ observe a narrow peaks at 1750, 1795,1850 MeV/$c^2$. The statistical significance of these peaks has been estimated as 5.6, 3.3 and 3.0 S.D., respectively. There are the small enhancements in mass regions of (1650-1675) and (1925-1950) MeV/c$^2$. These would be candidates for the $N^0$ or the $Ξ^0$ pentaquark states. The $pK^0_s$ invariant mass spectrum shows resonant structures with $M_{K_s^0 p}$=1540, 1613, 1821 MeV/$c^2$. The statistical significance of these peaks have been estimated as 5.5,4.8 and 5.0 s.d., respectively. There are also small peaks in 1487(3 s.d.),1690(3.6 s.d.), 1750(2.3 s.d.) and 1980(3.0 s.d.) MeV/$c^2$ mass regions. The invariant mass spectrum S=-1 $Λp$ observe a narrow peaks at 2100, 2175,2285 and 2353 MeV/$c^2$. Their excess above background by the second method is 6.9, 4.9, 3.8 and 2.9 S.D., respectively. There is also a small peak in 2225(2.2 s.d.) MeV/$c^2$ mass region.