Orbital and radial excitations of B hadrons

Present situation

The evidence and the production rate for B** orbital excitations decaying into B(*) pi has been published by DELPHI in 95: Phys. Lett. B345 (1995) 598 and can be accessed . Preliminary results containing also 1994 data have been shown . Other ALEPH and OPAL collaborations have obtained similar signals. Evidence for radial excitations of B hadrons has been reported by DELPHI at the HEP96 conference but it remains unpublished.

What remains to be done

The published Delphi result on orbital excitations uses only data registered between 1991 and 1993. Large improvements can be expected using also 1994 and 1995 and the new BSAURUS package. The following points need to be clarified and published: - the rate of 27% measured by DELPHI seems high and there are discrepancies between experiments. From the production rates measured for narrow D** states in c-jets and using models one predicts b-->Bu,d** of the order of 20%. And this rate must include "narrow" and "broad" states. So the observed bump must contain also the "broad" states. It would be nice to try to have an experimental evidence for this. Which implies that "broad" states are not so broad. - B** --> B* pi decays can be studied using B* candidates. - decay angular distributions can be published - DELPHI is the only experiment which has shown evidence for the production of B(*)' (radial excitations):B(*)' --> B(*) pi+ pi-. This result has to be confirmed by a second analysis and published.

Tools and contact-persons

The analysis can be done using the BSAURUS package. Contact persons: