Evidence of New States Decaying into $\Xi^{\prime}_{c}\pi$

TL;DR

This paper reports evidence for two new charmed baryons decaying into $\\Xi^{\prime}_{c}\pi$, with measured mass differences, interpreted as $J^P=1/2^-$ states analogous to known charmed baryons.

Contribution

The discovery of two new charmed baryons decaying into $\\Xi^{\prime}_{c}\pi$ and their interpretation as $J^P=1/2^-$ states is a novel contribution.

Findings

Evidence for two new charmed baryons decaying into $\\Xi^{\prime}_{c}\pi$.

Measured mass differences of approximately 318 and 324 MeV.

Interpretation as $J^P=1/2^-$ $\\Xi_{c1}$ states.

Abstract

Using 13.7 $fb^{-1}$ of data recorded by the CLEO detector at CESR, we report evidence for two new charmed baryons: one decaying into $\Xi_c^{0 \prime}\pi^+$ with the subsequent decay $\Xi_c^{0 \prime} \to \Xi_c^0 \gamma$, and its isospin partner decaying into $\Xi_c^{+ \prime} \pi^-$ followed by $\Xi_c^{+\prime} \to \Xi_c^+\gamma$. We measure the following mass differences for the two states: $M(\Xi_c^0 \gamma \pi^+)-M(\Xi_c^0)$=318.2+-1.3+-2.9 MeV, and $M(\Xi_c^+ \gamma \pi^-)-M(\Xi_c^+)$=324.0+-1.3+-3.0 MeV. We interpret these new states as the $J^P = 1/2^- \Xi_{c1}$ particles, the charmed-strange analogs of the $\Lambda_{c1}^+(2593)$.