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

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1

F. De Fazio INFN Bari Hadron 2011

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

SLIDE 2

2

F. De Fazio INFN Bari Hadron 2011

Open charm/beauty states

D0(2308), D’1(2440)
Ds0

*(2317), D’s1(2460)

D(2550), D(2600), D(2750), D(2760)
DsJ(2632)
DsJ(2860), DsJ(2710), DsJ(3040)
B1(5734), B*

2(5738)

Bs1(5830), B*

s2 (5840)

SLIDE 3

3

F. De Fazio INFN Bari Hadron 2011

Open charm/beauty states

D0(2308), D’1(2440)
Ds0

*(2317), D’s1(2460)

D(2550), D(2600), D(2750), D(2760)
DsJ(2632)
DsJ(2860), DsJ(2710), DsJ(3040)
B1(5734), B*

2(5738)

Bs1(5830), B*

s2 (5840)

Seen only by SELEX, never confirmed

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4

F. De Fazio INFN Bari Hadron 2011

Open charm/beauty states

D0(2308), D’1(2440)
Ds0

*(2317), D’s1(2460)

D(2550), D(2600), D(2750), D(2760)
DsJ(2632)
DsJ(2860), DsJ(2710), DsJ(3040)
B1(5734), B*

2(5738)

Bs1(5830), B*

s2 (5840)

Seen only by SELEX, never confirmed

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5

F. De Fazio INFN Bari Hadron 2011

Hadrons containing a single heavy quark Q

Spin of the heavy quark and of the light degrees of freedom decoupled in the mQ → ∞ limit

Q M

s s J   

 +

=

angular momentum

f the light degrees of freedom (conserved)

Mesons classified as doubl ublets

In the HQ limit:
states with the same

sl

P degenerate

finite mQ corrections
remove degeneracy between the states of the same doublet
induce mixing between states with the same JP

q

s L s   



+ =

spin

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6

F. De Fazio INFN Bari Hadron 2011

Qq multiplets

2 / 1 s =

l

−

1 1 L = 2 / 1 s =

l

2 / 3 s =

l

+ +

1 2 / 3 s =

l

2 / 5 s =

l

−

1

P

J

−

2 L = 2 L =

− +

1

+

2

−

2

−

3

fundamental doublet: (D(s),D*

(s)), (B(s),B* (s))

P-wave doublets: (D(s)1,D*

(s)2), (B(s)1,B* (s)2)

(D*

(s)0,D’ (s)1), (B* (s)0,B’ (s)1)

D-wave doublets: (D’(s)2,D(s)3), (B’(s)2,B(s)3) (D*

(s)1,D(s)2), (B* (s)1,B(s)2)

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7

F. De Fazio INFN Bari Hadron 2011

Qq multiplets

2 / 1 s =

l

−

1 1 L = 2 / 1 s =

l

2 / 3 s =

l

+ +

1 2 / 3 s =

l

2 / 5 s =

l

−

1

P

J

−

2 L = 2 L =

− +

1

+

2

−

2

−

3

Strong g transitions betwee een multip iple lets

d-wave transition

2 3

+

− +

→ 2 1 2 3

+ pseudoscalar meson

− +

→ 2 1 2 1

2 1

+

mesons are expected to be broad mesons are expected to be narrow + pseudoscalar meson

s-wave transition

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8

F. De Fazio INFN Bari Hadron 2011

cq multiplets

2 / 1 s =

l

−

1 1 L = 2 / 1 s =

l

2 / 3 s =

l

+ +

1 2 / 3 s =

l

2 / 5 s =

l

−

1

P

J

−

2 L = 2 L =

− +

1

+

2

−

2

−

3

) 1865 ( D ), 1869 ( D

±

) 2007 ( D ), 2010 ( D

* *±

) 2420 ( D1

±

) 2460 ( D

,0 * 2 ±

Low ly lyin ing Rad Rad. . Excita tati tions

) 2308 ( D*0 ) 2430 ( D 0

1

′ MeV 40

* 2

D ≈

Γ MeV 20

1

D ≈

Γ MeV 260

D ≈

Γ MeV 384

1

D ≈

Γ ′ ? ) 2550 ( D ? ) 2600 ( D ? ) 2760 ( D ), 2750 ( D

SLIDE 9

9

F. De Fazio INFN Bari Hadron 2011

cs multiplets

2 / 1 s =

l

−

1 1 L = 2 / 1 s =

l

2 / 3 s =

l

+ +

1 2 / 3 s =

l

2 / 5 s =

l

−

1

P

J

−

2 L = 2 L =

− +

1

+

2

−

2

−

3 ) 1968 ( Ds ) 2112 ( D*

s

) 2536 ( Ds1 ) 2573 ( D*

s2

MeV 2.3

s1

D <

Γ MeV 20

* s2

D ≈

Γ

Low ly lyin ing

SLIDE 10

10

F. De Fazio INFN Bari Hadron 2011

Narrow peak in the Ds

+ π0 mass distribution: DsJ(2317)

2.32 GeV GeV

) ( ) (

+ +

−

s s

D M D M π

Ba BaBa Bar CL CLEO EO Belle le production also observed at a fixed target exp

bserved width consistent with exp. Resolution (<10 MeV)

intrinsic width smaller

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11

F. De Fazio INFN Bari Hadron 2011

DsJ(2317) quantum numbers

The narrow width suggests Isospin violating decay i.e. confirmed by the absence of isospin partners eventually decaying in ,

1 I ≠



π

± s

D

± ±π s

D

) 2317 ( π

s sJ

D D →

+

= 0

P

J

I=0 is the preferred assignment The observation of the mode DsJ(2317) → Dsπ0 favours the assignment JP=0+ Also suggested by the helicity angle distribution Consistent with being flat

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12

F. De Fazio INFN Bari Hadron 2011

Another narrow peak in the Ds

*+π0 mass distribution: DsJ(2460)

M(Ds

*+ π0 ) - M(Ds *+)

Belle lle Ba BaBa Bar

CL CLEO EO 2.4 .46 GeV GeV width consistent with exp resolution

SLIDE 13

13

F. De Fazio INFN Bari Hadron 2011

DsJ produced in B decays: B→ D DsJ

Ds(2317)→πoDs Ds(2460)→πoDs

*

Ds(2460)→γDs

Belle observes radiative decay of DsJ(2460) rules out J ut J=0 =0 spin in 1 Analysis of helicity angle distribution suggests J= J=1

SLIDE 14

14

F. De Fazio INFN Bari Hadron 2011

DsJ(2317) & DsJ(2460)

The two narrow states identified as the JP=(0+,1+) lowest lying cs states with L=1

are data consistent with this interpretation?
are data consistent with other interpretations?

Understanding if DsJ(2317) and DsJ (2460) can be identified with the JP=(0+,1+) lowest lying cs states with L=1 means checking that

the isospin violating decays to Ds

(*)π0 proceed at a rate larger than the radiative modes

the total rate should not exceed the exp upper bound Γ≤ 10 MeV

SLIDE 15

15

F. De Fazio INFN Bari Hadron 2011

Hadronic modes

π

η

Ds (Ds

*)

D*

s0 (Ds1 ' )

The decays D*

s0 (D’s1) → Ds (*) π0 can be described

as the result of the strong transition Ds0 (D’s1) → Ds

(*) η

followed by the π-η mixing

h

3 2 2 2 2 2 *

*

) 1 ( 2 16 1 ) (

π π π

π π p p m m m m m m M M f h D D

u d s u d D D s s

s s

+             + − − = → Γ

P. Colangelo, FDF

PLB570, 180

P. Colangelo, R. Ferrandes, FDF

MPLA19, 2083

KeV 1 7 ) ) 2460 ( ( KeV 1 7 ) ) 2317 ( (

*

± = → Γ ± = → Γ π π

s

D D D D

sJ s sJ

Isospin violation enters here computed by sum rules

SLIDE 16

16

F. De Fazio INFN Bari Hadron 2011

Radiative modes: Light-cone sum rule predictions

The largest computed rate corresponds to the largest measured radiative branching ratio (mc → ∞)

P. Colangelo, A. Ozpineci, FDF

PRD 72 , 074004

PDG DG DsJ(2317) a and DsJ(2460) beha ehave as ordinar ary cs cs mesons

SLIDE 17

17

F. De Fazio INFN Bari Hadron 2011

cs multiplets

2 / 1 s =

l

−

1 1 L = 2 / 1 s =

l

2 / 3 s =

l

+ +

1 2 / 3 s =

l

2 / 5 s =

l

−

1

P

J

−

2 L = 2 L =

− +

1

+

2

−

2

−

3 ) 1968 ( Ds ) 2112 ( D*

s

) 2536 ( Ds1 ) 2573 ( D*

s2

Low ly lyin ing

SLIDE 18

18

F. De Fazio INFN Bari Hadron 2011

cs multiplets

2 / 1 s =

l

−

1 1 L = 2 / 1 s =

l

2 / 3 s =

l

+ +

1 2 / 3 s =

l

2 / 5 s =

l

−

1

P

J

−

2 L = 2 L =

− +

1

+

2

−

2

−

3 ) 1968 ( Ds ) 2112 ( D*

s

) 2536 ( Ds1 ) 2573 ( D*

s2

Low ly lyin ing

) 2317 ( D*

s0

) 2460 ( D'

s1

SLIDE 19

19

F. De Fazio INFN Bari Hadron 2011

cs multiplets

2 / 1 s =

l

−

1 1 L = 2 / 1 s =

l

2 / 3 s =

l

+ +

1 2 / 3 s =

l

2 / 5 s =

l

−

1

P

J

−

2 L = 2 L =

− +

1

+

2

−

2

−

3 ) 1968 ( Ds ) 2112 ( D*

s

) 2536 ( Ds1 ) 2573 ( D*

s2

Low ly lyin ing

) 2317 ( D*

s0

) 2460 ( D'

s1

D*K t K threshold D K K threshold ld

MeV 8 . 3 < Γ MeV 5 . 3 < Γ

SLIDE 20

20

F. De Fazio INFN Bari Hadron 2011

DsJ

sJ(2860

2860)

BaBar Collab., PRL 97 (06) 222001

Discovered by BaBar Collab.
Reconstructed in

and in

+ + − + + − +

→ → K K K K K D ) ( ) ( π π π

S

K D+

MeV 10 7 48 MeV . 5 5 . 1 6 . 2856 M ± ± = Γ ± ± =

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

de D

DK are e allo llowed

SLIDE 21

21

F. De Fazio INFN Bari Hadron 2011

cs multiplets

2 / 1 s =

l

−

1 1 L = 2 / 1 s =

l

2 / 3 s =

l

+ +

1 2 / 3 s =

l

2 / 5 s =

l

−

1

P

J

−

2 L = 2 L =

− +

1

+

2

−

2

−

3 ) 1968 ( Ds ) 2112 ( D*

s

) 2536 ( Ds1 ) 2573 ( D*

s2

) 2317 ( D*

s0

) 2460 ( D'

s1

Low ly lyin ing Rad Rad excitat ations

SLIDE 22

22

F. De Fazio INFN Bari Hadron 2011

cs multiplets

2 / 1 s =

l

−

1 1 L = 2 / 1 s =

l

2 / 3 s =

l

+ +

1 2 / 3 s =

l

2 / 5 s =

l

−

1

P

J

−

2 L = 2 L =

− +

1

+

2

−

2

−

3 ) 1968 ( Ds ) 2112 ( D*

s

) 2536 ( Ds1 ) 2573 ( D*

s2

) 2317 ( D*

s0

) 2460 ( D'

s1

Low ly lyin ing Rad Rad excitat ations for

rbidd

dden for

rbidd

dden for

rbidd

dden for

rbidd

dden for

rbidd

dden

SLIDE 23

23

F. De Fazio INFN Bari Hadron 2011

cs multiplets

2 / 1 s =

l

−

1 1 L = 2 / 1 s =

l

2 / 3 s =

l

+ +

1 2 / 3 s =

l

2 / 5 s =

l

−

1

P

J

−

2 L = 2 L =

− +

1

+

2

−

2

−

3 ) 1968 ( Ds ) 2112 ( D*

s

) 2536 ( Ds1 ) 2573 ( D*

s2

) 2317 ( D*

s0

) 2460 ( D'

s1

Low ly lyin ing Rad Rad excitat ations allo llowed allo llowed for

rbidd

dden for

rbidd

dden allo llowed allo llowed allo llowed for

rbidd

dden for

rbidd

dden for

rbidd

dden

SLIDE 24

24

F. De Fazio INFN Bari Hadron 2011

DsJ(2710)

Belle Collab.: analysis of the mode

+ + →

K D D B

New resonance decaying to D0K+ with:

MeV 23 108 MeV 9 2708

36 31 11 10

± ± = Γ ± ± = M

J=0 J=1 J=2 JP=1 =1- fa favoured A broad structure at M=2688 MeV with Γ=112 MeV was found by BaBar in the DK mass distribution implies P=-1

− − − →

1

SLIDE 25

25

F. De Fazio INFN Bari Hadron 2011

cs multiplets

2 / 1 s =

l

−

1 1 L = 2 / 1 s =

l

2 / 3 s =

l

+ +

1 2 / 3 s =

l

2 / 5 s =

l

−

1

P

J

−

2 L = 2 L =

− +

1

+

2

−

2

−

3 ) 1968 ( Ds ) 2112 ( D*

s

) 2536 ( Ds1 ) 2573 ( D*

s2

) 2317 ( D*

s0

) 2460 ( D'

s1

Low ly lyin ing Rad Rad excitat ations

SLIDE 26

26

F. De Fazio INFN Bari Hadron 2011

cs multiplets

2 / 1 s =

l

−

1 1 L = 2 / 1 s =

l

2 / 3 s =

l

+ +

1 2 / 3 s =

l

2 / 5 s =

l

−

1

P

J

−

2 L = 2 L =

− +

1

+

2

−

2

−

3 ) 1968 ( Ds ) 2112 ( D*

s

) 2536 ( Ds1 ) 2573 ( D*

s2

) 2317 ( D*

s0

) 2460 ( D'

s1

Low ly lyin ing Rad Rad excitat ations

* s1

D

* s

D

′

SLIDE 27

27

F. De Fazio INFN Bari Hadron 2011

DsJ(2860) & DsJ(2710)

predictions on allowed decay rates can help to distinguish among the various possibilities HQ HQ lim limit it: the members of the doublets are described by effective fields:

−

= 2 1 sP

 +

= 2 1 sP

 +

= 2 3 sP

 −

= 2 3 sP

 −

= 2 5 sP



L=0 L=1 L=2

SLIDE 28

28

F. De Fazio INFN Bari Hadron 2011

DsJ(2860) & DsJ(2710)

Interactions with the emission of a light pseudoscalar meson described by effective Lagrangian terms H H H π S H H π T H H π X H H π X’ X’ H H π Analogous terms describe interactions involving radial excitation doublets:

,... ~ , ~ h h g g → →

SLIDE 29

29

F. De Fazio INFN Bari Hadron 2011

DsJ(2860) : results for width ratios

P. Colangelo, S. Nicotri, FDF

PLB 642, 48

1 2 3 4 5

Would explain the observed narrowness

SLIDE 30

30

F. De Fazio INFN Bari Hadron 2011

DsJ(2860)

Our supported option:

5

Sig

ignal expected in in D*K

Small signal expected also in Ds η

In this case the small width can be attributed to the suppression due to the kaon momentum factor: f-wave transition The spin 2 partner could decay in p-wave due to the effect of 1/mQ corrections may escape detection Our ur conclusion

n:

DsJ(2860) is likely to be a JP=3- state Should decay to D*K Assuming the experimentally measured width would predict in the typical range of these couplings 5 .

2 1

≈ + k k

SLIDE 31

31

F. De Fazio INFN Bari Hadron 2011

Identifying DsJ(2710) through its decay modes

P. Colangelo, S. Nicotri, M. Rizzi, FDF
Phys. Rev. D77, 014012

the dependence on the (unknown) couplings drops out The D*K decay is the signal that must be investigated in order to distinguish the two possible assignments

SLIDE 32

32

F. De Fazio INFN Bari Hadron 2011

BaBar Analysis of D*K final states

D*K invariant mass spectrum

(background-subtracted)

angular analysis

Three peaks are visible: The angular distribution is consistent with the expectations for states with natural parity (0+,1-,2+,3-,…) for Ds1(2710) and DsJ(2860) excluded by the observation

f the D*K mode

BaBar, PRD80 (09 )092003

MeV 35 239 ) ) 3040 ( ( MeV 8 3044 ) ) 3040 ( ( MeV 6 3 48 ) ) 2860 ( ( MeV 2 2862 ) ) 2860 ( ( MeV 7 149 ) ) 2710 ( ( MeV 2 2710 ) ) 2710 ( (

46 42 30 5 5 2 39 52 * 1 12 7 * 1 syst stat sJ syst stat sJ syst stat sJ syst stat sJ syst stat s syst stat s

D D m D D m D D m ± ± = Γ ± ± = ± ± = Γ ± ± = ± ± = Γ ± ± =

+ + + + + +

SLIDE 33

33

F. De Fazio INFN Bari Hadron 2011

BaBar Analysis of D*K final states

D*K invariant mass spectrum

(background-subtracted)

angular analysis

Three peaks are visible: The angular distribution is consistent with the expectations for states with natural parity (0+,1-,2+,3-,…) for Ds1(2710) and DsJ(2860) excluded by the observation

f the D*K mode

BaBar, PRD80 (09 )092003

MeV 35 239 ) ) 3040 ( ( MeV 8 3044 ) ) 3040 ( ( MeV 6 3 48 ) ) 2860 ( ( MeV 2 2862 ) ) 2860 ( ( MeV 7 149 ) ) 2710 ( ( MeV 2 2710 ) ) 2710 ( (

46 42 30 5 5 2 39 52 * 1 12 7 * 1 syst stat sJ syst stat sJ syst stat sJ syst stat sJ syst stat s syst stat s

D D m D D m D D m ± ± = Γ ± ± = ± ± = Γ ± ± = ± ± = Γ ± ± =

+ + + + + +

to be discussed later…

SLIDE 34

34

F. De Fazio INFN Bari Hadron 2011

BaBar Analysis of D*K final states

Branching fractions

syst stat sJ sJ syst stat s s

DK D B K D D B DK D B K D D B 19 . 15 . 10 . 1 ) ) 2860 ( ( ) ) 2860 ( ( 12 . 13 . 91 . ) ) 2710 ( ( ) ) 2710 ( (

* 1 * 1

± ± = → → ± ± = → →

+ + + +

Supports the identification of Ds1(2710) with 23S1 (first radial excitation of Ds

*)

Does not support or discard unambiguously any interpretation: still to be understood

SLIDE 35

35

F. De Fazio INFN Bari Hadron 2011

cs multiplets

2 / 1 s =

l

−

1 1 L = 2 / 1 s =

l

2 / 3 s =

l

+ +

1 2 / 3 s =

l

2 / 5 s =

l

−

1

P

J

−

2 L = 2 L =

− +

1

+

2

−

2

−

3 ) 1968 ( Ds ) 2112 ( D*

s

) 2536 ( Ds1 ) 2573 ( D*

s2

) 2317 ( D*

s0

) 2460 ( D'

s1

Low ly lyin ing Rad Rad excitat ations

SLIDE 36

36

F. De Fazio INFN Bari Hadron 2011

cs multiplets

2 / 1 s =

l

−

1 1 L = 2 / 1 s =

l

2 / 3 s =

l

+ +

1 2 / 3 s =

l

2 / 5 s =

l

−

1

P

J

−

2 L = 2 L =

− +

1

+

2

−

2

−

3 ) 1968 ( Ds ) 2112 ( D*

s

) 2536 ( Ds1 ) 2573 ( D*

s2

) 2317 ( D*

s0

) 2460 ( D'

s1

Low ly lyin ing Rad Rad excitat ations

) 2710 ( DsJ ? ) 2860 ( DsJ

SLIDE 37

37

F. De Fazio INFN Bari Hadron 2011

DsJ(3040)

The only additional information is that it decays → D*K YES → DK NO JP=1+, 2-, 3+,…

SLIDE 38

38

F. De Fazio INFN Bari Hadron 2011

cs multiplets

2 / 1 s =

l

−

1 1 L = 2 / 1 s =

l

2 / 3 s =

l

+ +

1 2 / 3 s =

l

2 / 5 s =

l

−

1

P

J

−

2 L = 2 L =

− +

1

+

2

−

2

−

3 ) 1968 ( Ds ) 2112 ( D*

s

) 2536 ( Ds1 ) 2573 ( D*

s2

) 2317 ( D*

s0

) 2460 ( D'

s1

Low ly lyin ing Rad Rad excitat ations

) 2710 ( DsJ ? ) 2860 ( DsJ

SLIDE 39

39

F. De Fazio INFN Bari Hadron 2011

cs multiplets

2 / 1 s =

l

−

1 1 L = 2 / 1 s =

l

2 / 3 s =

l

+ +

1 2 / 3 s =

l

2 / 5 s =

l

−

1

P

J

−

2 L = 2 L =

− +

1

+

2

−

2

−

3 ) 1968 ( Ds ) 2112 ( D*

s

) 2536 ( Ds1 ) 2573 ( D*

s2

) 2317 ( D*

s0

) 2460 ( D'

s1

Low ly lyin ing Rad Rad excitat ations

) 2710 ( DsJ ? ) 2860 ( DsJ ) 3040 ( DsJ ) 3040 ( DsJ ) 3040 ( DsJ ) 3040 ( DsJ

SLIDE 40

40

F. De Fazio INFN Bari Hadron 2011

cs multiplets

2 / 1 s =

l

−

1 1 L = 2 / 1 s =

l

2 / 3 s =

l

+ +

1 2 / 3 s =

l

2 / 5 s =

l

−

1

P

J

−

2 L = 2 L =

− +

1

+

2

−

2

−

3 ) 1968 ( Ds ) 2112 ( D*

s

) 2536 ( Ds1 ) 2573 ( D*

s2

) 2317 ( D*

s0

) 2460 ( D'

s1

Low ly lyin ing Rad Rad excitat ations

) 2710 ( DsJ ? ) 2860 ( DsJ ) 3040 ( DsJ ) 3040 ( DsJ ) 3040 ( DsJ ) 3040 ( DsJ

would imply an (unlikely) mass inversion if DsJ(2860) has been properly placed

SLIDE 41

41

F. De Fazio INFN Bari Hadron 2011

DsJ(3040): how to discriminate among the four possibilities?

info from Relativistic Quark Model (RQM)
Allowed strong decays:
to D*

(s) + light pseudoscalar meson

DK, D

sη

to members of higher doublets + a light pseudoscalar meson

D*

0K, D

, D*

s0 , D’

D’1K D1K, K, D D*

2K

to D(s) + a light vector meson

DK DK*, D , Ds φ

SLIDE 42

42

F. De Fazio INFN Bari Hadron 2011

DsJ(3040): how to discriminate among the four possibilities?

1

~

s

D′

decays in s-wave to D*K, Ds

* η (broader), has the largest R1 ,

the largest width to light vector mesons

P. Colangelo , FDF

PRD81, 094001

SLIDE 43

43

F. De Fazio INFN Bari Hadron 2011

DsJ(3040): how to discriminate among the four possibilities?

1

~

s

D′

decays in s-wave to D*K, Ds

* η (broader), has the largest R1 ,

the largest width to light vector mesons

the two 2- states should not be observed in the decay to light vector mesons
P. Colangelo , FDF

PRD81, 094001

SLIDE 44

44

F. De Fazio INFN Bari Hadron 2011

DsJ(3040): how to discriminate among the four possibilities?

1

~

s

D′

decays in s-wave to D*K, Ds

* η (broader), has the largest R1 ,

the largest width to light vector mesons

the two 2- states should not be observed in the decay to light vector mesons
Ds2 cannot decay to D1K but should have the largest width to D2

*K

P. Colangelo , FDF

PRD81, 094001

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DsJ(3040): how to discriminate among the four possibilities?

1

~

s

D′

decays in s-wave to D*K, Ds

* η (broader), has the largest R1 ,

the largest width to light vector mesons

the two 2- states should not be observed in the decay to light vector mesons
Ds2 cannot decay to D1K but should have the largest width to D2

*K

look at the features of the spin partner
P. Colangelo , FDF

PRD81, 094001

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F. De Fazio INFN Bari Hadron 2011

DsJ(3040): how to discriminate among the four possibilities?

1

~

s

D′

decays in s-wave to D*K, Ds

* η (broader), has the largest R1 ,

the largest width to light vector mesons

the two 2- states should not be observed in the decay to light vector mesons
Ds2 cannot decay to D1K but should have the largest width to D2

*K

look at the features of the spin partner
P. Colangelo , FDF

PRD81, 094001

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F. De Fazio INFN Bari Hadron 2011

Hidden charm (conventional) states

Belle, BaBar 05

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F. De Fazio INFN Bari Hadron 2011

Hidden charm states (?)

From N. Brambilla et al. EPJ C71 (11) 1534

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Hidden beauty states

BaBar & CLEO (08) to be confirmed BaBar & CLEO (04) very recently discovered puzzling states: Zb(10610) & Zb(10650) decaying to ϒ(nS nS) ) π± (n=1,2,3) and hb(mP mP) ) π± (m=1,2) in ϒ(5S) decays in association with a single charged pion favoured quantum numbers I=1, =1, JP=1 =1+ decays to ϒ and hb occur with comparable rates → no spin-flip suppression Belle 2011, to be confirmed To be confirmed and interpreted: Yb(10888)

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Exotic interpretations

Mole lecula lar state: loosely bound state of a pair of mesons. The dominant binding mechanism should be pion exchange. Being weakly bound, mesons tend to decay as if they were free Disti tincti tive fe features of

f mu

multiquark picture re wit ith res espe pect to charmo monium:

prediction of many new states
possible existence of states with non-zero charge, strangeness or both

Tetraquark: Bound state of four quarks (diquark-antidiquark) quarks grouped into colour triplet scalar

r vector clusters.

Strong decays via rearrangement processes Charmo monium hyb hybrids States with an excited gluonic degree of freedom 0+-, 1-+, 2+-…quantum numbers are not possible for cc states but are possible for hybrids → would unambiguously signal an exotic state Lattice predictions for the lowest lying hybrid: M฀ 4.2 GeV Thresho hold effect cts Virtual enhancement of cross section that may not indicate a resonance.

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X(3872): discovery and properties

Observed in 2003 by four experiments in two production channels:

From R. Van Kooten, D0

mass very close to D0D*0 threshold: M(X(3872) )

)– (M (MD0+MD*

D*0) =

) = -0.32 ± 0. 0.35 35 GeV GeV

very small width: Γ <

< 2. 2.3 3 GeV @ 90% c.l.

X→ J/ψ π π

consistent with originating from X → J/ψ ρ → C=+1

from angular distributions in X→ J/ψ π π (CDF) → JPC= 1++ ( χ’c1 ) or JPC= 2-+ ( ηc2 )
search for charged partners produced no result → I=0

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X(3872): decays to two or three pions

3 . 4 . . 1 ) / ( ) / ( ± ± = → →

− + − +

π ψπ π π ψπ J X B J X B Isospin violation Two and three pion modes were found with: Possible explanation:

2 . ) / ( ) / ( 3 . 4 . . 1 ) / ( ) / ( ≅ → → ⇒ ± ± = → →

− + − +

ψω ψρ π ψπ π π ψπ J X A J X A J X B J X B

phase space severely suppressed phace space not very suppressed

Suzuki, PRD 72, 114013

BaBar studies the πππ distribution in X → J/ψ ω which seeems too favour a p-wave decay JP=2 =2- however in in contras ast with other properties of X

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X(3872): radiative decays to J/ψ γ and ψ(2S) γ

May help in distinguishing the different possibilities

if X=

X= χ’c1 → X→ψ(2S) γ should have a rate larger than X → J/ψ γ

if X=

X= ηc2 or X=composite object → X→ψ(2S) γ is suppressed with respect to X → J/ψ γ Ba BaBa Bar gives: while Belle lle: 4 . 1 4 . 3 ) / ) 3872 ( ( ) ) 2 ( ) 3872 ( ( ± = → Γ → Γ γ ψ γ ψ J X S X . 2 ) / ) 3872 ( ( ) ) 2 ( ) 3872 ( ( < → Γ → Γ γ ψ γ ψ J X S X

Barnes et al, PRD 72, 054026 Swanson, PLB 598, 197

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X(3872): mole lecule ule vs char armoniu ium

c u u c

Swanson, Brateen, Voloshin X proximity to DD* threshold may suggest that a molecular state made of charmed mesons contributes to the structure of X Mixing of the molecule (dominant component) with other states such as pure charmonium no definite isospin radiative decays In the molecular scenario arise from the radiative decays of the individual vector mesons γ γ

− +

→ → D D X D D X &

γ γ γ

± ± →

→ → D D D D D D

* * *

& ,

Vol Volos

shin

and the decay is strongly suppressed with respect to γ

− +

→ D D X γ D D X → If ob

bser

erved, the he suppr ppression of

f

w with h res espe pect to

wou
uld s

suppor pport t the m he mol

lec

ecular inter erpretation? γ

− +

→ D D X γ D D X →

SLIDE 55

55

X(3872) as the first radial excitation of χc1 : radiative decays

Standard mechanism for radiative X transitions into charmed states Pole diagrams known from exp data Unknown coupling Intermediate (3770)

ψ

DD

gψ

Intermediate D*

1

ˆ g c′

Unknown coupling Can be obtained from data

n radiative D* decays

c

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F. De Fazio INFN Bari Hadron 2011

X(3872) as the first radial excitation of χc1 : radiative decays

Can be evaluated as a function of the ratio of the two unknown couplings

1

ˆ g c

R<0.7 in the cc description R is very small for small values of (when the ψ pole contribution is negligible) the he s suppr ppression of

f R is not
t pec

peculiar of

f the m

he mol

lec

ecular s scen enario Very small values of R

1

ˆ g c

P. Colangelo, S. Nicotri, FDF

PLB 650, 16611

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X(3872) as the first radial excitation of χc1 : hadronic decays

1

ˆ g

Exp bound Values of typical of hadronic couplings can reproduce the small width of X(3872)

1

ˆ g

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Heavy quark mass limit for heavy quarkonium states

HQ spin simmetry YE

YES S

HQ flavour symmetry NO

NO Usual classification for the states:

J s L

n

1 2 +

s = spin L = orbital angular momentum J = total angular momentum radial quantum number with:

s L L

C P

+ +

− = − = ) 1 ( ) 1 (

1

L=0 ↔ S- wave states L=1 ↔ P- wave states L=2 ↔ D- wave states …..

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Multiplets for heavy quarkonium states

L=0 multiplet

spin 1 state spin 0 state n=1 n=2

( ) ( )

) 2 ( ), 2 ( ) 1 ( ), 1 ( S S S S

c c

ψ η ψ η

L=1 multiplet

spin 2 spin 1 spin 0 triplet singlet spin 1 n=1

( ) [ ]

) 1 ( , ) 1 ( ), 1 ( ), 1 (

2 1

P h P P P

c c c c

χ χ χ

L=2 multiplet

triplet spin 3 triplet spin 2 triplet spin 1 singlet spin 2

( ) [ ]

, , ,

2 1 3 3 2 3 1 3

D n D n D n D n

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Effective Lagrangian for radiative transitions of heavy quarkonia

F. De Fazio,

PRD 79, 054015

P ↔ S
D ↔ P

photon a single constant describes all the transitions among the various members of the P and S multiplets

reduced theoretical uncertainty
model independence

idem for transitions among members of D and P multiplets

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1P → 1S transitions

Exploting known data: spin symm mmetry t turns out to be exp xperimentally well s satisfied averaged result: + total widths of χcJ states can be used to predict:

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2S → 1P transitions

possibility to exploit data in the beauty sector: define width ratio and coupling ratio even though the coupling might be different passing from beauty to charm, it is reasonable to assume that the ratios of the couplings stay stable we can predict analogous charm ratios

) (c J

R

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2S → 1P transitions

prediction for J=1: =1: Identifing X(3872) with χc1(2P) and using the data: and are close enough to consider the assumption X(3872) = χc1(2P) plausible to be contrasted with composite scenarios in which X(3872) → ψ(2S)γ is suppressed with respect to X(3872) → ψ(1S)γ

) ( 1 c

R

X

R

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Concluding remarks

open charm mesons:
all the observed cs states classified as ordinary mesons
the most intriguing challenge remains to understand why

D*

s0 (2317) and D’s1(2460) have masses below the D(*)K threshold

HQ symmetry predicts analogous states in the beauty system :

M(B*

s0)=5721 MeV decaying to Bs π0

M(B’s1)=5762 MeV decaying to B*

s π0

quarkonium like states:
X(3872) still puzzling state
identification with χ’c1 plausible ( according to my analysis of radiative decays)
Many other states not discussed

Strongly required independent confirmation of charged quarkonium-like states (at present only Belle has evidence)

P. Colangelo et al.

MPLA 19, 2083