First determination of the spin and parity of the charmed-strange baryon <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mi mathvariant="normal">Ξ</mml:mi><mml:mi>c</mml:mi></mml:msub><mml:mo stretchy="false">(</mml:mo><mml:mn>2970</mml:mn><mml:msup><mml:mo stretchy="false">)</mml:mo><mml:mo>+</mml:mo></mml:msup></mml:math>

We report results from a study of the spin and parity $\Xi_{c}(2970)^+$ using $980~\mathrm{fb^{-1}}$ data sample collected by Belle detector at KEKB asymmetric-energy $e^{+}e^{-}$ collider. The decay angle distributions in chain $\Xi_{c}(2970)^+ \to \Xi_c(2645)^{0}\pi^{+} \Xi_c^{+}\pi^{-}\pi^{+}$ are analyzed to determine this charmed-strange baryon. angular strongly favor $J =1/2$ over $3/2$ or $5/2$, under an assumption that lowest partial wave dominates decay. also measure ratio branching fractions $R={\mathcal{B}[ \Xi_{c}(2970)^+ ]} / { \mathcal{B}[ \Xi_c^{\prime0}\pi^{+} =1.67 \pm 0.29\mathrm{(stat.)}^{ +0.15}_{ -0.09}\mathrm{(syst.)} 0.25\mathrm{(IS)}$, where last uncertainty is due possible isospin-symmetry-breaking effects. This $R$ value favors spin-parity $J^P=1/2^+$ with light-quark degrees freedom $s_{l}=0$. first determination