EXOTIC BARYONS INSPIRE   JSON PDGID:
B172

${{\mathit P}_{{{c {{\overline{\mathit c}}}}}}{(4457)}^{+}}$

$I(J^P)$ = $1/2(?^{?})$ 

was ${{\mathit P}_{{{c}}}{(4450)}}$
A resonance seen in ${{\mathit \Lambda}_{{{b}}}^{0}}$ $\rightarrow$ ${{\mathit P}_{{{c}}}^{+}}{{\mathit K}^{-}}$, then ${{\mathit P}_{{{c}}}}$ $\rightarrow$ ${{\mathit J / \psi}}{{\mathit p}}$, with a significance of 12 standard deviations. The ${{\mathit J / \psi}}{{\mathit p}}$ quark content is ${{\mathit u}}{{\mathit u}}{{\mathit d}}{{\mathit c}}{{\overline{\mathit c}}}$, a pentaquark. See also the ${{\mathit P}_{{{c {{\overline{\mathit c}}}}}}{(4380)}^{+}}$. In the best amplitude fit, the two states have opposite parity, one having $\mathit J = 3/2$, the other $\mathit J = 5/2$. Extraction of the pentaquark signals requires some understanding of the dominant ${{\mathit K}^{-}}{{\mathit p}}$ background. AAIJ 2015P used a model-dependent approach. AAIJ 2016AG reanalyzed the data making minimal assumptions about the ${{\mathit K}^{-}}{{\mathit p}}$ background, and thus confirmed the strong significance of the pentaquark signals.
${{\mathit P}_{{{c {{\overline{\mathit c}}}}}}{(4457)}^{+}}$ MASS $4457.3^{+4.0}_{-1.8}$ MeV 
 
${{\mathit P}_{{{c {{\overline{\mathit c}}}}}}{(4457)}^{+}}$ WIDTH $6.4^{+6.0}_{-2.8}$ MeV 
 
Mode  
Fraction ($\Gamma_i$ / $\Gamma$) Scale Factor/
Conf. Level
P(MeV/c)  
$\Gamma_{1}$ ${{\mathit J / \psi}}{{\mathit p}}$ seen 828
 
$\Gamma_{2}$ ${{\mathit \Lambda}_{{{c}}}^{+}}{{\overline{\mathit D}}^{0}}$ not seen  
 
$\Gamma_{3}$ ${{\mathit \Lambda}_{{{c}}}^{+}}{{\mathit \pi}^{+}}{{\mathit D}^{-}}$ not seen  
 
$\Gamma_{4}$ ${{\mathit \Sigma}_{{{c}}}{(2455)}^{++}}{{\mathit D}^{-}}$ not seen  
 
$\Gamma_{5}$ ${{\mathit \Sigma}_{{{c}}}{(2520)}^{++}}{{\mathit D}^{-}}$ not seen  
 
$\Gamma_{6}$ ${{\overline{\mathit \Lambda}}_{{{c}}}^{-}}{{\mathit \pi}^{+}}{{\mathit D}^{+}}$ [1] not seen  
 
$\Gamma_{7}$ ${{\overline{\mathit \Sigma}}_{{{c}}}{(2455)}^{0}}{{\mathit D}^{+}}$ [1] not seen  
 
$\Gamma_{8}$ ${{\overline{\mathit \Sigma}}_{{{c}}}{(2520)}^{0}}{{\mathit D}^{+}}$ [1] not seen  
 
$\Gamma_{9}$ ${{\mathit \Lambda}_{{{c}}}^{+}}{{\mathit \pi}^{+}}{{\mathit D}^{*-}}$ not seen  
 
$\Gamma_{10}$ ${{\overline{\mathit \Lambda}}_{{{c}}}^{-}}{{\mathit \pi}^{+}}{{\mathit D}^{*+}}$ [1] not seen  
 
[1] Searched for the charge conjugate mode from ${{\overline{\mathit P}}_{{{c {{\overline{\mathit c}}}}}}^{-}}$ decays.