Quantitative predictions for B semileptonic decays into D, D{sup {asterisk}}, and the orbitally excited D{sup {asterisk}{asterisk}} in quark models in the manner of Bakamjian and Thomas

Journal Article · Sat Nov 01 04:00:00 EST 1997 · Physical Review, D

DOI:https://doi.org/10.1103/PhysRevD.56.5668· OSTI ID:543896

Morenas, V ^[1]; Le Yaouanc, A; Oliver, L; Pene, O; Raynal, J ^[2]

---

1. Laboratoire de Physique Corpusculaire, Universite Blaise Pascal - CNRS/IN2P3, F-63177 Aubiere Cedex (France)
2. Laboratoire de Physique Theorique et Hautes Energies, Universite de Paris XI, Batiment 211, 91405 Orsay Cedex (France)

Once chosen the dynamics in one frame, the rest frame in this paper, the Bakamjian-Thomas method allows one to define relativistic quark models in any frame. These models have been shown to provide, in the infinite quark mass limit, fully covariant current form factors as matrix elements of the quark current operator. In this paper we use the rest frame dynamics fitted from the meson spectrum by various authors, already shown to provide a reasonable value for {rho}{sup 2}. From the general formulas for the scaling invariant form factors {xi}{sup (n)}(w), {tau}{sub 1/2}{sup (n)}(w), and {tau}{sub 3/2}{sup (n)}(w), we predict quantitavely the B semileptonic branching ratios to the ground state and orbitally excited charmed mesons D, D{sup {asterisk}}, and D{sup {asterisk}{asterisk}}. We check Bjorken{close_quote}s sum rule and discuss the respective contributions to it. We find {xi}(w){approx_equal}[2/(1+w)]{sup 2}, resulting from the fact that the ground state wave function is Coulomb-like. We also find {tau}{sub 3/2}{approx_equal}0.5[2/(1+w)]{sup 3} and {tau}{sub 1/2}(w){lt}{tau}{sub 3/2}(w). Very small branching ratios into j=1/2 orbitally excited D{close_quote}s results. The overall agreement with experiment is rather good within the present accuracy which is poor for the orbitally excited charmed mesons. We predict a ratio B(B{r_arrow}D{sub 2}{sup {asterisk}}l{nu})/B(B{r_arrow}D{sub 1}l{nu})=1.55{plus_minus}0.15 as a mere consequence of the heavy quark symmetry. If some faint experimental indications that B(B{r_arrow}D{sub 1}l{nu}){approx_equal}B(B{r_arrow}D{sub 2}{sup {asterisk}}l{nu}) were confirmed, it would indicate a sizable O(1/m{sub c}) correction. {copyright} {ital 1997} {ital The American Physical Society}

• OSTI ID: 543896
• Journal Information: Physical Review, D, Journal Name: Physical Review, D Journal Issue: 9 Vol. 56; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
B MESONS
BRANCHING RATIO
D MESONS
D*-2010 MESONS
D*2-2460 MESONS
EXCITED STATES
FORM FACTORS
GROUND STATES
MATRIX ELEMENTS
QUARK MODEL
SCALE INVARIANCE
SEMILEPTONIC DECAY
SUM RULES
WAVE FUNCTIONS