Understanding DsJ*(2317) and DsJ(2460) OUTLINE Spectroscopy of mesons containing a single heavy quark New evidences of positive parity charmed states Evaluation of their strong and radiative widths Predictions in the beauty sector Rossella Ferrandes Bari University Frascati, 17 May 2005

chromomagnetic interaction Description of hadrons containing a single heavy quark Q QCD lagrangian for the heavy quark: chromomagnetic interaction kinetic energy spin flavour symmetric subleading in the limit

Q q Qq mesons are classified in doublets labeled by SlP: Sl = Sq + L In the infinite heavy quark mass limit, the heavy quark spin SQ and the light degrees of freedom angular momentum Sl decouple Q q Qq mesons are classified in doublets labeled by SlP: J = Sl + SQ Sl = Sq + L States differing for the heavy quark spin orientation are degenerate in mass.

Strong decays M (MeV) D2* D1 D1 D0* D* D slP=1/2- slP=1/2+ slP=3/2+ 2600 D2* D1 2400 s-wave decays (broad) D1 D0* 2200 D* 2000 D 1800 d-wave decays (narrow) slP=1/2- slP=1/2+ slP=3/2+

Belle cu cd Broad states previously established slP=3/2+ axial vector newly found slP=1/2+ scalar previously established slP=3/2+ tensor newly found slP=1/2+ axial vector previously established slP=3/2+ axial vector Broad states

cs BaBar CLEO DsJ*(2317) DsJ(2460) Belle narrow states

helicity analyses favour J=1 Spin-parity assignment for DsJ*(2317) observation of decay natural spin-parity: 0+, 1-, 2+... decay not observed BaBar 0+ assignment favoured decay not observed Spin-parity assignment for DsJ(2460) observation of decay spin-parity: 0-, 1+, 2-... Belle observation of decay J=0 assignment ruled out observation of decay JP= 1+ favoured helicity analyses favour J=1

Different interpretations: For slP= 1/2+ strange states potential models typically predict masses larger than the experimental values, above the DK and D*K thresholds 2504 MeV So slP= 1/2+ states were expected to have large widths 2364 MeV In the interpretation as cs states, the experimental resonances are narrow because of isospin violation. Different interpretations: 4-quark state (H. Y. Cheng et al. 03) molecule (Barnes, Close, Lipkin 03) atom (Szczepaniak 03) … BaBar Looking for isospin partners: CDF

To identify the experimental resonances with cq states of SlP=1/2+ doublet we must calculate strong widths calculate radiative widths obtaining for non strange states: large widths for strange states: width < experimental resolution according to experimental values

Effective lagrangian describing interactions between heavy mesons and pseudoscalar light mesons based on heavy quark spin-flavour symmetry chiral symmetry for light mesons Q qa

Analogously for the axial state: Strong decays Non strange states h (QCD sum rules) P. Colangelo et al., PRD (95) Considering also decay Experimentally: Analogously for the axial state:

Gasser and Leutwyler, NPB (1985) Strange states Isospin violating decays mixing Gasser and Leutwyler, NPB (1985) Analogously for the scalar state:

Casalbuoni et al., Phys. Rept. (1997) Radiative decays suppressed as 1/mc VMD (Vector Meson Dominance) Casalbuoni et al., Phys. Rept. (1997)

Overall agreement with experiments supports our interpretation Summary of the results: P. Colangelo, F. De Fazio, PLB (03) P. Colangelo, F. De Fazio, RF, MPL A (04) meson experimental width (MeV) evaluated width (MeV) Overall agreement with experiments supports our interpretation 0.1 predictions 0.5 0.2 0.4 the role of 1/mc corrections currently under investigation

chromomagnetic interaction centre of mass of the doublet Predictions for beauty mesons belonging to 1/2+ doublet M=P, V M=S, A kinetic energy chromomagnetic interaction centre of mass of the doublet

Analogously for non strange states: 1 meson mass (MeV/c2) width (MeV/c2)

Experimental measurements consistent with canonical interpretation CONCLUSIONS Charm sector Strange states: widths << experimental resolution Experimental measurements consistent with canonical interpretation consistent with experimental values Non strange states: widths consistent with experimental measurements (~100 MeV) Beauty sector Predictions of masses and widths for beauty mesons belonging to 1/2+ doublet

Backup transparencies

Analogous situation for and doublets cq mesons bq mesons Mesons belonging to doublet Analogous situation for and doublets

experimental masses large states narrow states