Latest developments in the Spectroscopy of Heavy Hadrons Fulvia De - PowerPoint PPT Presentation

Latest developments in the Spectroscopy of Heavy Hadrons Fulvia De Fazio INFN - Bari Questi tion: recent discoveries in charm(onium) and bottom (onium) spectra might be exotic states? Collaborators: P. Colangelo, R. Ferrandes, S. Nicotri, A. Ozpineci, M. Rizzi F. De Fazio INFN Bari Hadron 2011 1

Open charm/beauty states • D 0 (2308), D’ 1 (2440) * (2317), D’ s1 (2460) • D s0 • D(2550), D(2600), D(2750), D(2760) • D sJ (2632) • D sJ (2860), D sJ (2710), D sJ (3040) • B 1 (5734), B * 2 (5738) • B s1 (5830), B * s2 (5840) F. De Fazio INFN Bari Hadron 2011 2

Open charm/beauty states • D 0 (2308), D’ 1 (2440) * (2317), D’ s1 (2460) • D s0 • D(2550), D(2600), D(2750), D(2760) • D sJ (2632) Seen only by SELEX, never confirmed • D sJ (2860), D sJ (2710), D sJ (3040) • B 1 (5734), B * 2 (5738) • B s1 (5830), B * s2 (5840) F. De Fazio INFN Bari Hadron 2011 3

Open charm/beauty states • D 0 (2308), D’ 1 (2440) * (2317), D’ s1 (2460) • D s0 • D(2550), D(2600), D(2750), D(2760) • D sJ (2632) Seen only by SELEX, never confirmed • D sJ (2860), D sJ (2710), D sJ (3040) • B 1 (5734), B * 2 (5738) • B s1 (5830), B * s2 (5840) F. De Fazio INFN Bari Hadron 2011 4

Hadrons containing a single heavy quark Q Spin of the heavy quark and of the light degrees of freedom decoupled in the m Q → ∞ limit       angular momentum =  + spin J s s = + s L s M Q of the light degrees of freedom (conserved)  q Mesons classified as doubl ublets • In the HQ limit: P degenerate - states with the same s l • finite m Q corrections - remove degeneracy between the states of the same doublet - induce mixing between states with the same J P F. De Fazio INFN Bari Hadron 2011 5

Qq multiplets P J − 3 D-wave doublets: s = 5 / 2 − (D’ (s)2, D (s)3 ), (B’ (s)2, B (s)3 ) 2 l L = 2 − s = 2 3 / 2 l (D * (s)1, D (s)2 ), (B * (s)1, B (s)2 ) − 1 + P-wave doublets: 2 s = 3 / 2 + 1 (D (s)1, D * (s)2 ), (B (s)1, B * (s)2 ) l L = 1 s = + 1 / 2 1 l (D * (s)0, D ’ (s)1 ), (B * (s)0, B ’ (s)1 ) + 0 − 1 s = L = 1 / 2 0 fundamental doublet: (D (s), D * (s) ), (B (s), B * (s) ) l − 0 F. De Fazio INFN Bari Hadron 2011 6

Qq multiplets P J − Strong g transitions betwee een multip iple lets 3 s = 5 / 2 − 2 l L = 2 − s = 2 3 / 2 l − 1 + − + 3 1 2 → 2 + pseudoscalar meson 2 s = 3 / 2 + 1 d-wave transition l L = + 1 3 mesons are expected to be narrow s = + 1 / 2 2 1 l + 0 + − 1 1 → 2 + pseudoscalar meson − 1 2 s-wave transition s = L = 1 / 2 0 + l 1 − mesons are expected to be broad 0 2 F. De Fazio INFN Bari Hadron 2011 7

cq multiplets P J Low ly lyin ing Rad. Rad . Excita tati tions − 3 s = 5 / 2 − 2 l L = 2 D ( 2750 ), D ( 2760 ) ? − s = 2 3 / 2 l − 1 Γ D ≈ ± 40 MeV * ,0 + D ( 2460 ) * 2 2 2 s = Γ D ≈ 3 / 2 + ± 20 MeV 1 D 1 ( 2420 ) l 1 L = 1 Γ ′ D ≈ ′ s = D 0 + 384 MeV ( 2430 ) 1 / 2 1 1 l 1 + Γ D ≈ D *0 0 ( 2308 ) 260 MeV 0 0 − * ± * 0 1 D ( 2010 ), D ( 2007 ) D ( 2600 ) ? s = L = 1 / 2 0 l ± − 0 D ( 1869 ), D ( 1865 ) D ( 2550 ) ? 0 F. De Fazio INFN Bari Hadron 2011 8

cs multiplets P J Low ly lyin ing − 3 s = 5 / 2 − 2 l L = 2 − s = 2 3 / 2 l − 1 Γ D ≈ 20 MeV + D * ( 2573 ) 2 * s2 s2 s = Γ D < 3 / 2 + 2.3 MeV 1 D s1 ( 2536 ) l L = s1 1 s = + 1 / 2 1 l + 0 − D * ( 2112 ) 1 s s = L = 1 / 2 0 l − D s ( 1968 ) 0 F. De Fazio INFN Bari Hadron 2011 9

+ π 0 mass distribution: D sJ (2317) Narrow peak in the D s BaBa Ba Bar Belle le 2.32 GeV GeV CL CLEO EO + + π − 0 M ( D ) M ( D ) s s production also observed at a fixed target exp observed width consistent with exp. Resolution (<10 MeV) intrinsic width smaller F. De Fazio INFN Bari Hadron 2011 10

D sJ (2317) quantum numbers I ≠ The narrow width suggests Isospin violating decay i.e. 1 confirmed by the absence of isospin partners ± ± π ± eventually decaying in , π  D D s s I=0 is the preferred assignment + → π = 0 0 P ( 2317 ) D D J sJ s The observation of the mode D sJ (2317) → D s π 0 favours the assignment J P =0 + Also suggested by the helicity angle distribution Consistent with being flat F. De Fazio INFN Bari Hadron 2011 11

*+ π 0 mass distribution: D sJ (2460) Another narrow peak in the D s 2.4 .46 GeV GeV CL CLEO EO *+ π 0 ) - M(D s *+ ) M(D s Belle lle width consistent with exp resolution BaBa Ba Bar F. De Fazio INFN Bari Hadron 2011 12

D sJ produced in B decays: B → D D sJ D s (2317) →π o D s D s (2460) →π o D s * Belle observes radiative decay of D sJ (2460) D s (2460) →γ D s rules out J ut J=0 =0 Analysis of helicity angle distribution suggests J= J=1 spin in 1 13 F. De Fazio INFN Bari Hadron 2011

D sJ (2317) & D sJ (2460) The two narrow states identified as the J P =(0 + ,1 + ) lowest lying cs states with L=1 • are data consistent with this interpretation? • are data consistent with other interpretations? Understanding if D sJ (2317) and D sJ (2460) can be identified with the J P =(0 + ,1 + ) lowest lying cs states with L=1 means checking that (*) π 0 proceed at a rate larger than the radiative modes • the isospin violating decays to D s • the total rate should not exceed the exp upper bound Γ ≤ 10 MeV F. De Fazio INFN Bari Hadron 2011 14

Hadronic modes P. Colangelo, FDF (*) π 0 can be described The decays D * s0 (D’ s1 ) → D s PLB570, 180 (*) η P. Colangelo, R. Ferrandes, FDF as the result of the strong transition D s0 (D’ s1 ) → D s MPLA19, 2083 followed by the π - η mixing * ) D s ( D s π 0 ' ) D * s 0 ( D s 1 η h computed by sum rules Isospin violation enters here 2     − 2 2 M m 1 h m m   Γ → π = + π D 0 * 0 3 d u ( D D ) s ( 1 ) p + π π s 0 s   0 2 2 m m 16 f M p −   d u m π * 0 D s 0   s 2 Γ → π = ± 0 ( D ( 2317 ) D ) 7 1 KeV sJ s Γ → π = ± * 0 ( D ( 2460 ) D ) 7 1 KeV sJ s F. De Fazio INFN Bari Hadron 2011 15

Radiative modes: Light-cone sum rule predictions ( m c → ∞ ) PDG DG P. Colangelo, A. Ozpineci, FDF PRD 72 , 074004 The largest computed rate corresponds to the largest measured radiative branching ratio D sJ (2317) a and D sJ (2460) beha ehave as ordinar ary cs cs mesons F. De Fazio INFN Bari Hadron 2011 16

cs multiplets P J Low ly lyin ing − 3 s = 5 / 2 − 2 l L = 2 − s = 2 3 / 2 l − 1 + D * ( 2573 ) 2 s2 s = 3 / 2 + 1 D s1 ( 2536 ) l L = 1 s = + 1 / 2 1 l + 0 − D * ( 2112 ) 1 s s = L = 1 / 2 0 l − D s ( 1968 ) 0 F. De Fazio INFN Bari Hadron 2011 17

cs multiplets P J Low ly lyin ing − 3 s = 5 / 2 − 2 l L = 2 − s = 2 3 / 2 l − 1 + D * ( 2573 ) 2 s2 s = 3 / 2 + 1 D s1 ( 2536 ) l L = 1 s = D ' + ( 2460 ) 1 / 2 1 s1 l + D * 0 ( 2317 ) s0 − D * ( 2112 ) 1 s s = L = 1 / 2 0 l − D s ( 1968 ) 0 F. De Fazio INFN Bari Hadron 2011 18

cs multiplets P J Low ly lyin ing − 3 s = 5 / 2 − 2 l L = 2 − s = 2 3 / 2 l − 1 + D * ( 2573 ) 2 s2 s = 3 / 2 + 1 D s1 ( 2536 ) l L = 1 D*K t K threshold s = D ' + ( 2460 ) 1 / 2 Γ < 1 3 . 5 MeV s1 l D K K threshold ld + D * 0 ( 2317 ) Γ < 3 . 8 MeV s0 − D * ( 2112 ) 1 s s = L = 1 / 2 0 l − D s ( 1968 ) 0 F. De Fazio INFN Bari Hadron 2011 19

D sJ sJ (2860 2860) • Discovered by BaBar Collab. • Reconstructed in + → − π + + 0 D K ( K ) K − + + → π π 0 ( K ) K D + 0 and in K S = ± ± M 2856 . 6 1 . 5 5 . 0 MeV BaBar Collab., PRL 97 (06) 222001 Γ = ± ± 48 7 10 MeV Quantum number assignment required in order to identify it Possibilities: - low lying state not yet observed - radial excitation of an already observed state Only ly states that ca can dec decay to the he observe rved mode ode D DK are e allo llowed F. De Fazio INFN Bari Hadron 2011 20

cs multiplets P Low ly lyin ing Rad excitat Rad ations J − 3 s = 5 / 2 − 2 l L = 2 − s = 2 3 / 2 l − 1 + D * ( 2573 ) 2 s2 s = 3 / 2 + 1 D s1 ( 2536 ) l L = 1 s = D ' + ( 2460 ) 1 / 2 1 s1 l + D * 0 ( 2317 ) s0 − D * ( 2112 ) 1 s s = L = 1 / 2 0 l − D s ( 1968 ) 0 F. De Fazio INFN Bari Hadron 2011 21

cs multiplets P Low ly lyin ing Rad Rad excitat ations J − 3 s = 5 / 2 − for orbidd dden 2 l L = 2 − s = 2 3 / 2 for orbidd dden l − 1 + D * ( 2573 ) 2 s2 s = 3 / 2 + 1 D s1 ( 2536 ) l for orbidd dden L = 1 s = D ' + ( 2460 ) for orbidd dden 1 / 2 1 s1 l + D * 0 ( 2317 ) s0 − D * ( 2112 ) 1 s s = L = 1 / 2 0 l − D s ( 1968 ) for orbidd dden 0 F. De Fazio INFN Bari Hadron 2011 22