Observation of narrow baryon resonance in $p{K}_s^0$ mode in $pA$-interactions at $70GeV/c$ with SVD-2 setup

Abstract

We report on the SVD-2 experiment data analysis aimed to search for an exotic baryon state, the ${\Theta }^{+}$-baryon, in a $p{K}_s^0$ decay mode with IHEP U-70 accelerator proton beam at $70GeV/c$. A resonant structure with $M=1526\pm 3(stat.)\pm 3(syst.)MeV/c^2$ and $\Gamma <24MeV/c^2$ was found in the $p{K}_s^0$ invariant mass spectrum, with the statistical significance of this peak estimated as $5.6\sigma$.

4 pages, 4 figures, First International Workshop "Hadron Structure and QCD", HSQCD-2004, Repino, St. Petersburg, Russia, May 2004