Charmed Baryons

The L=0 (no angular momentum between quarks) baryons are shown in intro:plets. The singly charmed baryons (including the and states on which this thesis focuses) are on the second level of these multiplets, while the doubly charmed baryons, which are the subject of doublec, are those on the third level of the multiplets. With the exception of the and $\Omega_c^{\prime 0}$ (both shown in intro:delta-plet), all of the L=0 singly charmed baryons in intro:plets have (likely) been observed. The properties of the L=0charmed baryons are listed in intro:cbaryons. In addition, several L=1 and excited states have been observed: the , the , and most recently the $\Xi_{c1}(2720)$ [18].

  

Figure 1.2: SU(4) baryon multiplets which show all the L=0 baryons present in a four-quark system. Extending these diagrams to SU(5) for the baryons containing a quark would require a 4-dimensional drawing. (Figure from pdg:pdg98.)

[ $\frac{1}{2}^+$ baryons with the SU(3) octet (states) as a base.]

intro:nucleon-plet [ $\frac{3}{2}^+$ baryons with the SU(3) decuplet ($\Delta$ states) as a base.]

intro:delta-plet

 

Table 1.4: Properties of the L=0 charmed baryons [4]. The I(J^P) values of many of these states have not been experimentally measured; in these cases we give the predicted values. Baryons with $J = \half$ belong to the SU(4) multiplet shown in intro:nucleon-plet while those with $J = \threehalf$ belong to the multiplet shown in intro:delta-plet.

	Quark
Baryon	content	Mass ()	I(JP)
	$\cq(\uq\dq)_a$	$2284.9 \pm 0.6$	$0(\half ^+)$
	$\cq\dq\dq$	$2452.9 \pm 0.6$	$1(\half ^+)$
	$\cq(\uq\dq)_s$	$2453.6 \pm 0.9$	$1(\half ^+)$
	$\cq\uq\uq$	$2452.8 \pm 0.6$	$1(\half ^+)$
	$\cq\dq\dq$	$2517.5 \pm 1.4$	$1(\threehalf ^+)$
	$\cq\uq\dq$	unobserved	$1(\threehalf ^+)$
	$\cq\uq\uq$	$2519.4 \pm 1.5$	$1(\threehalf ^+)$
	$\cq(\sq\dq)_a$	$2471.8 \pm 1.4$	$\half(\half ^+)$
	$\cq(\sq\uq)_a$	$2466.3 \pm 1.4$	$\half(\half ^+)$
$\xic^{\prime 0}$	$\cq(\sq\dq)_s$	$2578.8 \pm 3.2$	$\half(\half ^+)$
$\xic^{\prime +}$	$\cq(\sq\uq)_s$	$2574.1 \pm 3.3$	$\half(\half ^+)$
$\xic^{*0}$	$\cq\sq\dq$	$2644.5 \pm 1.8$	$\half(\threehalf ^+)$
$\xic^{*+}$	$\cq\sq\uq$	$2647.4 \pm 2.0$	$\half(\threehalf ^+)$
	$\cq\sq\sq$	$2704.0 \pm 4.0$	$0(\half ^+)$
$\Omega_c^{\prime 0}$	$\cq\sq\sq$	unobserved	$0(\threehalf ^+)$