Physics – High Energy Physics – High Energy Physics - Phenomenology
Scientific paper
2001-05-15
Nucl.Phys. A696 (2001) 638-666
Physics
High Energy Physics
High Energy Physics - Phenomenology
21 pages, 2 figures
Scientific paper
10.1016/S0375-9474(01)01202-7
Phenomenological applications of an effective theory of low-lying excited states of charm and bottom isoscalar baryons are discussed at leading and next-to-leading order in the combined heavy quark and large $N_c$ expansion. The combined expansion is formulated in terms of the counting parameter $\lambda\sim 1/m_Q, 1/N_c$; the combined expansion is in powers of $\lambda^{1/2}$. We work up to next-to-leading order. We obtain model-independent predictions for the excitation energies, the semileptonic form factors and electromagnetic decay rates. The spin-averaged mass of the doublet of the first orbitally excited sate of $\Lambda_b$ is predicted to be approximately $5920 MeV$. It is shown that in the combined limit at leading and next-to-leading order there is only one independent form factor describing $\Lambda_b \to \Lambda_c \ell \bar{\nu}$; similarly, $\Lambda_b \to \Lambda_{c}^{*} \ell \bar{\nu}$ and $\Lambda_b \to \Lambda_{c1} \ell \bar{\nu}$ decays are described by a single independent form factor. These form factors are calculated at leading and next-to-leading order in the combined expansion. The electromagnetic decay rates of the first excited states of $\Lambda_c$ and $\Lambda_b$ are determined at leading and next-to leading order. The ratio of radiative decay rates $\Gamma(\Lambda_{c}^{*} \to \Lambda_c \gamma) / \Gamma(\Lambda_{b1} \to \Lambda_b \gamma)$ is predicted to be approximately 0.2, greatly different from the heavy quark effective theory value of unity.
Baccouche Aziza Z.
Chow Chi-Keung
Cohen Thomas D. .
Gelman Boris A.
No associations
LandOfFree
Excited Heavy Baryons and Their Symmetries III: Phenomenology does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Excited Heavy Baryons and Their Symmetries III: Phenomenology, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Excited Heavy Baryons and Their Symmetries III: Phenomenology will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-61514