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Experimental environment D sJ ’s and their properties X(3872)... ...and also Y(3940) cc recoil spectrum pentaquarks? Conclusion. New Resonances at Belle. B. Golob University of Ljubljana, Slovenia Belle Collaboration.

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New resonances at belle

  • Experimental environment

  • DsJ’s and their properties

  • X(3872)...

  • ...and also Y(3940)

  • cc recoil spectrum

  • pentaquarks?

  • Conclusion

New Resonances at Belle

B. Golob

University of Ljubljana, Slovenia

Belle Collaboration

B. Golob, Belle Cracow Epiphany Conference, 2005


New resonances at belle

Experimental environment

Mt. Tsukuba

e-

KEKB

B

Belle

Υ(4s)

~1 km in diameter

> 900 pb-1/day (~1 M BB/day)

e+

Integrated luminosity

∫Ldt = 255 fb-1 on reson.

30 fb-1 off reson.

~280 M BB

B

Oct ‘04

May ‘99

KEKB asymmetric B

factory

Υ(4s)

B. Golob, Belle Cracow Epiphany Conference, 2005


New resonances at belle

Experimental environment

Central Drift

Chamber

e+

3.5 GeV

s(pt)/pt=

0.3% √pt2+1

3(4) layer

Si vtx det.

e-

8 GeV

combined particle ID

e(K±)~85%

e(p±→K±)<~10%

@ p<3.5 GeV/c

Aerogel

Cherenkov

Counter

(n=1.015-

1.030)

m and KL

identification

(14/15 lyrs

RPC+Fe)

1.5T SC

solenoid

EM Calorimeter

CsI (16X0)

B. Golob, Belle Cracow Epiphany Conference, 2005


New resonances at belle

B

ECM/2

signal

ECM/2

U(4s)

e-

e+

signal

B

B

∑ pi, ∑ Ei

continuum

Experimental environment

Off reson. data:

continuum only

On reson. data:

BB (spherical) separated

from continuum

(jet shaped) on basis of

topological variables

e.g. angle

between B

direction

and beam

axis

B. Golob, Belle Cracow Epiphany Conference, 2005


New resonances at belle

DsJ states

Production in continuum

DsJ+(2460)→Ds+g

DsJ*(2317)+→Ds+p0

DsJ+(2460)→Ds*+p0

3.4

3.0

Mass (GeV)

2.6

Ds*+

2.2

Ds+

1.8

86.9 fb-1,PRL92,012002(2004)

M(DsJ(2317))=2317.2±0.5±0.9 MeV

M(DsJ(2460))=2456.5±1.3±1.3 MeV

Masses lower than

predicted

in potential models;

Widths consistent

with zero

B. Golob, Belle Cracow Epiphany Conference, 2005


New resonances at belle

DsJ states

Production in

B decays

B → DDsJ

Helicity angle:

Ds

DsJ

B

D

q

DsJ*(2317)+

→Ds+p0

g,p0

J=1

DsJ(2460)+

→Ds*+p0

DsJ(2460)+

→Ds+g

J=1

J=2

J=0

275M BB,BELLE-CONF-0461

DsJ*(2317)+→Ds+p0

DsJ(2460)+→Ds+g

Data agree with JP=0+ (DsJ(2317)) and 1+ (DsJ(2460))

Br(B0→D-DsJ*(2317)+)=(10.3±2.2±3.1)x10-4

B. Golob, Belle Cracow Epiphany Conference, 2005


New resonances at belle

First observation of B0→DsJ*-K+

DsJ states

M(Dsp0)-M(Ds)

DE

6.8 s signif.

0.2 0.3 0.4 0.5 0.6 (GeV)

-0.10 0 0.10 (GeV)

c

s

b

d

u

K+

Br(B0→DsJ*(2317)-K+)∙Br(DsJ*(2317)-→Ds-p0)

W

s

Br(B0→Ds-K+)

B0

d

152M BB,hep-ex/0409026

Br(B0→D-DsJ*(2317)+)∙Br(DsJ*(2317)+→Ds+p0)

DsJ

Br(B0→D-Ds+)

d

DsJ*(2317)-→Ds-p0

(Ds→fp,K*K,KSK)

Br(B0→DsJ(2317)-K+)∙ Br(DsJ(2317)-→Ds-p0)=

(5.3 ± 1.4± 0.7 ± 1.4)x10-5

4-quark

content?

<2.5x10-5 @90% CL

<0.94x10-5

<0.40x10-5

B→DsJ(2317)p-

B→DsJ(2460)K+

B→DsJ(2460)p-

= 1.8 ± 0.6

= 0.13 ± 0.05

B. Golob, Belle Cracow Epiphany Conference, 2005


New resonances at belle

Observed by Belle with

152M BB

B± → K± p+p-J/y

l+l-

How about with 275M BB?

152M BB,

PRL91,262001

(2003)

275M BB,S.Olsen,GHP’04

X(3872)

Calculate Mbc in 5 MeV bins ofM(p+p-J/y)

M(p+p-l+l-)-M(l+l-)

3865

MeV

48.6±7.8 evts.

(>10s)

M=3872.4

±0.7 MeV

3870

MeV

no. of

B’s in

bins of

M(p+p-J/y)

3875

MeV

M(p+p-l+l-)

B. Golob, Belle Cracow Epiphany Conference, 2005


New resonances at belle

B± → K± p+p- p0 J/y

Mbc andDE

in 25 MeV

bins of

M(p+p-p0)

X(3872)

-0.1 0.1

5.20 5.25 5.30

Mbc

DE

M(p+p-p0J/y)= M(X)± 3s

no. of B’s in

bins ofM(p+p-p0)

13.1±4.2 evts.(6.4s)

M(p+p-p0)>750 MeV

consistent with 0

First observation of decay mode

other than p+p-J/y;

subthreshold decay to wJ/y

(expected for DD* molecule)

C(X(3872))=+1

B. Golob, Belle Cracow Epiphany Conference, 2005


New resonances at belle

Dalitz plot for

B→ KwJ/y

Y(3940)

B→ Kp+p- p0 J/y

B± → K* J/y; K*→ K± w

Events in DE, Mbc signal region

resonant

structure?

M2(J/yw)

M(p+p-p0J/y)

B→

KwJ/y

M(p+p-p0)

M2(Kw)

For these

B→ KwJ/y

plot Mbc, DE in bins

ofM(wJ/y)

B. Golob, Belle Cracow Epiphany Conference, 2005


New resonances at belle

B± → K± wJ/y

No. of B’s

in bins of

M(wJ/y)

275M BB,

hep-ex/0408126

Y(3940)

40 MeV binsM(wJ/y)

3897

MeV

3937

MeV

3977

MeV

large

deviations

from phase

space

M(Y)=3943±11±13 MeV

G=87±22±26 MeV

58 ± 11 evts.

Fit with

added

BW

(8.1s)

Relatively large signal at

lowM(wJ/y)

Br(B→YK)Br(Y→wJ/y)=

(7.1±1.3±3.1)x10-5

B. Golob, Belle Cracow Epiphany Conference, 2005


New resonances at belle

cc recoil spectrum

X

e-

e+

J/y

hc

cc0

hc(2s)

well established method(e.g. double cc

production)

Reconstruct

J/y →l+l-

Calculate recoil mass (mass of X):

285 fb-1,T.Ziegler,GHP’04

new resonance

N=148 ± 33 (4.5 s)

M=3940 ± 11 MeV

Reconstruction of

additional D or D*

besideJ/y→

- new resonance decays

to DD*;

- not seen in J/y w

probably not Y(3940)

confirmation of hc(2s) after 1st

observation by Belle

B. Golob, Belle Cracow Epiphany Conference, 2005


New resonances at belle

Pentaquark searches

M(pK-)

y[cm]

L(1520)

M(pKS)

x[cm]

(KN+(1540)X)

(KN(1520)X)

< 2%(90%CL)

155M BB,hep-ex/0411005

Searches in decays,“high energy” (charm baryon,B)

Searches in secondary interactions,“low energy”

select pK secondary vtx

detector “tomography”:

M(pK-)fit

with D-wave

BW and

treshold

funct.;

L parameters

in agreement

with PDG

M(pKS) fit with 3rd order

poly.and narrow sig.(2 MeV)

at different m

assuming Br(+→pKS)=25%

B. Golob, Belle Cracow Epiphany Conference, 2005


New resonances at belle

Pentaquark searches

B0  p pKS

B0  p+ D(*)-p

B+  p pK+

B0 pD0p

B0  p+D-p

155M BB,hep-ex/0411005

B decays

Qc0

Q(1540)+

Qc*+

Q*(1600)++

303

±21

evts.

M(Qc0)=3099 MeV(H1)

s=3.5 MeV (det. resol.)

@90% CL

B. Golob, Belle Cracow Epiphany Conference, 2005


New resonances at belle

  • KEKB is also a great source of charm& cc states

  • Some expected, mainly unexpected/puzzling

    observations/discoveries

D**broad states

PRD69,112002

Y(3940)

hep-ex/0408126

DsJ properties

BELLE-CONF-0461

hep-ex/0409026

hc(2s)

PRL89,102001

PRD70,071102

PQ

searches

hep-ex/0411005

X(3872)→ wJ/y

S.Olsen,GHP’04

Sc(2800)

hep-ex/0412069

resonance in cc

recoil

T.Ziegler,GHP’04

Lc+ p structure

hep-ex/0409005

Conclusions

range of questions:

understanding

all properties

as expected?

why such

properties?

what are they?

will be addressed as more statisticsis collected

B. Golob, Belle Cracow Epiphany Conference, 2005


Pq backup
PQbackup


New resonances at belle

Pentaquark searches

M(pK-)

L(1520)

M(pKS)

(KN+(1540)X)

(KN(1520)X)

< 2%

155M BB,hep-ex/0411005

backup slide

Searches in sec. inter.

select pK secondary vtx

detector “tomography”:

M(pK-)fit

with D-wave

BW and

treshold

funct.;

L parameters

in agreement

with PDG

y[cm]

Q(1540)+

M(pKS) fit with

3rd order poly.

and narrow sig.

(2 MeV) at

different m

x[cm]

@90% CL

assuming Br(+→pKS)=25%

m

B. Golob, Belle Cracow Epiphany Conference, 2005


New resonances at belle

Pentaquark searches

L(1520)

p

p

formation

p(pK-)~500 MeV

K-

K-

L(1520)

p

p

production

majority

K-

K-

assuming Br(+→pKS)=25%

Br((1520)→pK-)=

0.5 Br((1520)X→NK)

ratio of e from MC

(KN+(1540)X)

(KN(1520)X)

< 2%(90%CL)

backup slide

L(1520)

spectrum

(fit to

M(pK-) in

mom. bins

formation

p

non-zero

strangeness

most pK vtx

produced by

strange

particles

vtx with addit.

track

distance

pK- vtx –

next track

distance

pK- vtx –

next K+

cm

B. Golob, Belle Cracow Epiphany Conference, 2005


D sj backup
DsJ backup


New resonances at belle

Production in B decays

DsJ states

backup slide

Decay channel Br[10-4] signif.

B  D DsJ(2317) [Dsp0] 10.1  1.5  3.0 9.5s

B  D DsJ(2317) [Ds*g] 4.0-1.4+1.5 (<8.4) 3.5s

B  D DsJ(2460) [Ds*p0] 14.8-2.5+2.8  4.4 8.6s

B  D DsJ(2460) [Dsg] 6.4  0.8  1.9 11s

B  D DsJ(2460) [Ds*g] 2.6-1.0+1.1 (<5.7) 3.0s

B  D DsJ(2460) [Dsp+p-] 1.0-0.4+0.5 (<2.3) 2.6s

B  D DsJ(2460) [Dsp0] 0.2-0.5+0.7 (<1.7) --

B  D* DsJ(2317) [Dsp0] 3.1-1.7+2.1 (<8.5) 2.0s

B  D* DsJ(2460) [Ds*p0] 28.7-6.4+7.4  8.6 6.9s

B  D* DsJ(2460) [Dsg] 12.7-2.0+2.2  3.8 10s

Br(DsJ(2460)→Ds+g)/Br(DsJ(2460)→Ds*+p0)=0.43±0.08±0.04

Br’s from DE fits in Mbc and M(DsJ) signal region

Largest syst. uncertainty from p0 eff. and D branching

fractions

B. Golob, Belle Cracow Epiphany Conference, 2005



New resonances at belle

Y(3940)

backup slide

B→ KwJ/y

DE in 40 MeV bins

ofM(wJ/y)

|DE| < 0.03 GeV, 5.2725< Mbc< 5.2875 GeV

all fits consistent yield

within stat. error (~200±20)

B yield inM(wJ/y)

bins for B→ KwJ/y

phase space MC

Yields determined from

simultaneous DE and Mbc fits

(constrained to be equal);

peak position and width from fits

to integrated distrib.

Fit with f(M)=Aq*(M)

q*(M): mom. of daughter part.

in wJ/y frame

B. Golob, Belle Cracow Epiphany Conference, 2005


New resonances at belle

Nw=74±14

Y(3940)

backup slide

B→ KwJ/y

M(p+p-p0)

DE, Mbc signal region

20% variation

included in

syst. error.

Ks,K± yields

consistent

with acc.

ratio.

acceptance

KS

M(wJ/y)

M(wJ/y)<3997 MeV

(first 3 bins in

M(wJ/y));

no resonance

in Kw in this

M(wJ/y) region

M(Kw)

DE, Mbc side band:

Nw=14±10(non-w 3p)

fraction of true w

in signal: 0.90±0.18

(in syst. error)

B. Golob, Belle Cracow Epiphany Conference, 2005


New resonances at belle

Y(3940)

backup slide

B→ KwJ/y

Main syst. uncertainty:

fit using S-wave BW or Lorentzian shape for resonance;

linear or 3rd order polynomial for bckg.;

largest deviation +38%

possible non-w 3p contribution;

-28%

Significance:

integral of fitted phase space in first 3 bins of M(wJ/y)

16.8±1.4

total number of events: 55.6

significance > 9s

> 8s

B. Golob, Belle Cracow Epiphany Conference, 2005


L c p structure backup
Lcp structure backup


New resonances at belle

Lc+ p structure

Sc(2455)0

Sc(2520)0

B-→ Lc+ p p-

D(1600)

D(2420)

152M BB,hep-ex/0409005

3-body baryon production in

B decays: baryon-antibaryon

system peaked near treshold

Fits to DE

in mass bins

264±20 evts.

Lc+ →pK-p+,pKS,Lp+,

pKSp+p-,Lp+p+p-

L→ pp-

BW peak + feed

down fromB-→ Lc+ D

M = 3.35 ± 0.02 GeV

50 ± 10 evts.(5.6 s)

G~70 MeV

B. Golob, Belle Cracow Epiphany Conference, 2005


New resonances at belle

Lc+ p

Lc+ p structure

Br(B-→ Sc(2455)0 p)=(3.67+0.74-0.66 ± 0.36 ± 0.95)∙10-5

Br(B-→ (Lc+ p)p-)=(3.87+0.77-0.72 ± 0.43 ± 1.01)∙10-5

Sc(2455)0 p

Sc(2455)0 p

simultaneous fit

to 6 DE distrib.;

Ni=SjeijYj

Lc+ D(2420)

Lc+ D(1600)

Lc+ D(1232)

due toBr( Lc+ → pK-p+ )

M=3.35 +0.01-0.02 ± 0.02 GeV

G=0.07 +0.04-0.03± 0.04 GeV

from different bkgd. param.

B. Golob, Belle Cracow Epiphany Conference, 2005