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XYZ News from Belle. XYZ mesons. Stephen L. Olsen, Univ of Hawai’i QWG 2006 June 26-30, Brookhaven. B-factories are Charmonium factories. c c production mechanisms @ a B factory: B meson decays e + e - annihilation gg collisions e + e - radiative return (isr).

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Xyz mesons

XYZ News from Belle

XYZ mesons

Stephen L. Olsen, Univ of Hawai’i

QWG 2006 June 26-30, Brookhaven


B factories are charmonium factories
B-factories are Charmonium factories

cc production mechanisms @ a B factory:

  • B meson decays

  • e+e- annihilation

  • gg collisions

  • e+e- radiative return (isr)


C c production in b decays
cc production in B decays

J = 0 or 1

j=½

j=½

Spectator model says Jcc= 0 or 1 should

dominate exclusive BK(cc) decays.


Allowed decays all have bf 10 3 from pdg2004
Allowed decays all have Bf~10-3from PDG2004

hcK 0.9 x10-3

J/yK 1.0 x10-3

J/yK* 1.4 x10-3

J/yK12701.8 x10-3

y’K 0.7 x10-3

y’K* 0.9 x10-3

cc0K 0.6 x10-3

cc1K 0.7 x10-3

BK cc(J=2) still not seen


E e j y c c
e+e- J/y + (cc)

J/y

hc’

cc0

X

hc

X (almost) always

contains (cc)

C(X) = +1

M(X)

consistent with bkg


Gg d d
gg DD

JPC = 0++, 2++

e+e- g (cc)

cc

JPC = 1--


Xyz particles in belle
XYZ particles in Belle

  • X(3872)

    • p+p- J/y in BKp+p-J/y

  • Z(3930)

    • DD in gg DD

  • Y(3940)

    • wJ/y in BK wJ/y

  • X(3940)

    • e+e-J/y X & e+e-  J/y DD*

  • Y(4260)

    • p+p-J/y in e+e-g p+p- J/y

NEW


Gg z 3931 dd at belle
gg  Z(3931) DD at Belle

sin4q (J=2)

Belle PRL 96, 082003 (2006)

4111 evts (5.5)

M=3931 4  2 MeV

=208 3 MeV

M(DD) GeV

Matches well to cc2’ expectations


Z 3930 candidate for the c c2
Z(3930): candidate for the cc2’

M= 3931 MeV is

~45 MeV low

G=20MeV too narrow?

3931

Masses from

Barnes, Godfrey & Swanson

PRD 72, 054026 (2005)


E e j y x 3940
e+e- J/yX(3940)

e+e-J/y + X

hep-ex 0507019 submitted to PRL


X 3940 d d seen d d w j y not seen
X(3940)D*D seen(DD & wJ/y not seen)

B(DD)<41%

B(D*D)>45%

From X(3940) → D*D:

M = (3943 ± 6 ± 6) MeV

G < 52 MeV at 90%CL


Is the x 3940 the h c
Is the X(3940) the hc”?

M= 3943 MeV is

~150 MeV low

G<52MeV too narrow?

3940


X 3872 in b k p p j y
X(3872) in BKp+p-J/y

y’p+p-J/y

X(3872)p+p-J/y

PRL 91, 262001

M(ppJ/y)


Also seen in pp
Also seen in pp

X(3872)

D0

CDF

11.6s

X(3872)

PRL 93, 072004 (2004)

PRL 93, 162002 (2004)

Production properties similar to those of the y’

hep-ex/0406022


C 1 is established
C=+1 is established

M(pp) looks like a r

X(3872)gJ/y seen in:

CDF

PRL 96 102002

Belle

hep-ex/0505037

Belle

&

X(3872)”w”J/y seen

Belle


ereJ/y

k(erxeJ/y)

0++ 0-+

Ruled out by Belle

qlp

y

c2/dof=34/9

c2/dof = 34/9

|cosq|

|cosqlp|

|cosy|

rule out 0++ & 0 -+


Angular analysis from cdf
Angular analysis from CDF

1++

or

2-+

Ilya Kravchenko: FPCP06


Belle threshold peak in b kd 0 d 0 p 0
Belle: Threshold peak in BKD0D0p0

Belle hep-ex/0606055  today!

M(DDp)

DE

+0.7

-1.7

M=3875.4  0.7  0.8 MeV

Br(BKX)Bf(XD0D0p0 )

= (1.27  0.31 )x10-4

+0.22

-0.39

Br(XD0D0p0)

Br(Xp+p-J/y)

~ 10


Comments on the d 0 d 0 p 0 mass peak
Comments on the D0D0p0 mass peak

PDG MX3872: 3871.2  0.5 MeV

~2s discrepancy

PDG05

2xPDG error on mD0

(could be  2.0 MeV)

+0.7

-1.7

Fitted M: 3875.4  0.7  0.8 MeV

DD* “Binding Energy?”:

Here error on

mD0 drops out

+0.7

-1.7

M–(mD0+ mD*0) = +4.3  0.7 MeV

Nominally ~2.3sabove D0D*0 threshold

(but errors are non-Gaussian)


X 3872 has no satisfactory c c assignment
X(3872) has no satisfactory cc assignment

3872

cc1’

Br(gJ/y) too small

& Br(rJ/y) too big

hc2

  • hc2rJ/y ispin forbidden

  • D0D0p0 @ thresh. suppressed

  • BKcc(J=2) suppressed


Y 3940 in b k w j y
Y(3940) in BK wJ/y

M≈3940 ± 11 MeV

G≈ 92 ± 24 MeV

G(Y3940 wJ/y)> 7 MeV

(an SUF(3) violating decay)

~

this is 103 x G(y’  hJ/y)

(another SUF(3) violating decay)

if the Z(3930) is the cc2’

the Y(3940) mass is too

high for it to be the cc1’

M(wJ/y) MeV

PRL94, 182002 (2005)


Is there a c c slot for y 3940
Is there a cc slot for Y(3940) ?

hc”

Mass is low

cc1’

Can M(cc1’)>M(cc2’)?

3940

3931

cc0’

“ “ “ “


E e g isr y 4260 at babar

233 fb-1

e+e- gisr Y(4260) at BaBar

BaBar PRL95, 142001 (2005)

Not seen in e+e- hadrons

X.H. Mo et al, hep-ex/0603024

Y(4260)

4260

BES data

s(e+e-+p-J/)~50pb

G(Y4260p+p- J/y) > 1.6MeV @ 90% CL

4260


Y 4260 at cleo iii

13.3 fb-1

BaBar

CLEO III

N

125  23 (~8)

14.1 +5.2 (4.9)

-4.2

Mass (MeV)

4259  8 +2

4283+17 4

-16

-6

Width (MeV)

88  23 +6

70 +40 5

-25

-4

Y(4260) at CLEO-III

ISR

(1S)-(4S)

13.3 fb-1

Consistent results

R.Poling @ Charm 2006


Y 4260 at belle
Y(4260) at Belle

M=4295  10 +11 MeV

G = 133  26 +13 MeV

-5

Select e+e- p+p-ℓ+ℓ- +X; Nchg=4

Mℓ+ℓ-=MJ/y30MeV; pJ/y>2 GeV; Mpp>0.4GeV

-6

| data

4.2<MppJ/y<4.4

Preliminary

MC

MX

For y’p+p-J/y in the same data:

M(y’) = 3685.3  0.1 MeV

(PDG: M(y’)=3686.09  0.04)


Babar vs cleo vs belle
BaBar vs CLEO vs Belle

-4.2

-5

-6

-16

-6

-4

-25

~2.5s different

“Full” report from Belle at ICHEP in Moscow


No 1 c c slot for the y 4260
No 1-- cc slot for the Y(4260)

X.H. Mo et al, hep-ex/0603024

4280

4280


Dd threshold in relation to the y 4260
DD** threshold in relation to the “Y(4260)”

D** spectrum

No obvious

distortions

4.28-mD

M(p+p-J/y) GeV


Summary
summary

  • Z(3931) (ggDD)

    • Probably the cc2’

  • X(3940) (e+e- J/y X)

    • C=+1

    • Could be the hc” (albeit with some stretching)

  • X(3872):

    • JPC = 1++

    • Br(Xp+p- J/y) large

    • Br(XD0D0p0) seen; ~ 10xBr(Xp+p-J/y)

D*D


Summary cont d

233 fb-1

summary cont’d

  • Y(3940)

    • G( Y3940 wJ/y) >7 MeVtoo

      large for charmonium

    • Mass too low for a hybrid

  • “Y(4260)”

    • Confirmed by Belle but at a higher mass

    • G(y4260p+p-J/y)>1.6 MeValso very large

    • JPC=1--, but not seen in e+e- hadrons

      - Straddles the D**D threshold, but with no obvious distortions to the ppJ/y line-shape


Conclusions

(mine, not Belle’s)

conclusions

  • There is a new hadron spectroscopy in the 3.5~4.5 GeV mass region

    • Maybe more than one

  • The new states are characterized by large partial widths (Bfs) to hadrons+J/y

    • Br(X(3872)rJ/y) > 4.3% (Isospin=1)

    • G(Y(3940)wJ/y) > 7 MeV (SU(3) octet)

    • G(Y(4260)p+p-J/y) > 1.6 MeV

  • There is no apparent transition at the D**D mass threshold




Look at e e j y d d
Look at e+e-J/y D(D(*))

  • Reconstruct a J/y & a D

    • use D0K-p+ & D+K-p+p+

  • Determine recoil mass


Inclusive b kx from babar
Inclusive BKx from BaBar

Fully reconstructed B- tags

?


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