Recent results from the E852 data analysis

• Motivation, E852 vs GlueX

• PWA basics

• 00 production

• and ’ spectra : have we seen exotics yet ?

• Computational challenge

• Outlook

‘Simplest’ QCD states

Lab for fundamental symmetry tests

Heavy QQ are non-relativistic

Light meson are chiral eigenstates

Beyond the quark model : glueballs, exotics

Bridge between QCD and the S-matrix theory

Why mesons ?

LS

S

1

2

S = S + S1 2

J = L + S

C = (-1)L + S

P = (-1)L + 1

JPC = 0--,0+-,1-+,2+-,

DSBquark model

Meson spectroscopy : open issues

over O(100) light mesons listed in the PDG ~ O(10) in the summary tables ~ O(1) properly described

S = (p + pp)2

t=(p’N – pp)2

M2x = (pa + pb)2 a

b

N’p

,

t/s << 1

Kinematics of peripheral production

s . 20 GeV2 , E, LAB =8-9 GeV

t < 1 GeV2 Mx . 2.5 GeV

s » 40 GeV2 , E, LAB =18 GeV

t < 1 GeV2 Mx . 3 GeV

E852 GlueX

You do it in all possible way to study systematics

0 physics input“maximal’ ambiguity

some physics input “moderate” ambiguities

… the less you know the more ambiguous the answer …

know everything no ambiguities

Dynamics of peripheral production I

a

b

c

d

t=sac

s=sab

s/t ! 1T(s,t)

(t)(t) s(t)

a c

b d

L = Re(t) Resonance (or bound state Im=0)

(18GeV) p a2 p 0 n

dN/dt

p n

-a2

t

s

Natural exchange ()

Unnatural exchange (b1)

Quasi-two body reactions

E852

II Multiple particle production - p ! 00 n

-

p

0

0

n_

s

s1

M

t1

t

s/t,s/t1,s/M2! 1

Regge + particle 4 point function

t,

- 0

0

1 ~FESR~

M2 ~ sM2<<s

00 spectrum

f2(1270)

(400-1200)

(J. Gunter et al.) 2001 - p ! 0 n

Combined analysis of CERN-Krakow-Munich and E852 data L.Lesniak at al.

badgood

=

O(p2/f2

)

+

Low order expansion

Higher order expansion

+ unitarization

Interplay between “elementary” (CDD) and “dynamical” resonances

(S=I=0)

only(no KK, no resonances)

+KK

2 Resonaces @ ~1.3, 1.5 GeV

Relevant partial waves :

S D0 D- Po P- (unnatural)

D+ P+ (natural)

Mass dependence

t-dependence

“Global features” of the ’ production

- p ! 0 n

a0 and a2 resonances

(A.Dzierba et al.) 2003 (M.Swat, Ph.D thesis) 2003

a2 1320

0 vs -

C is a good quantum number

ao and a2 are produced (helps with ambiguities)

o

ao 980

a2 1320

Work in progress on full - sample O(100K) events !

a0(980) not seen before exchange

very low t<0.1 GeV2

P-wave results from the 0 data

1(900 – 5GeV) emerges

Intensity in the weak P-waves is strongly affected by the a2(1320), strong wave due to acceptance corrections

No consistent B-W description of the P-wave fund when all helicity amplitudes where taken into account

1 BW resonance in P+

a2(1320)

2 BW resonances in D+

a2(1800) = ?

E852 ’ analysis

… combine Regge description with chiral constraints

s>>t,M

tRegge

Chiral

M

What is the origin of the P-wave in the , ’

rescattering (dual) to diffraction vs quasi-two body(resonance)

- p ! - pResults of coupled channel analysis of - p ! ’- p

D

S P

D

P

P-wave comes entirely from background : no resonances needed

- : 1(1400) > 350 MeV

’- : 1(1600) > 350 MeV

0 : 1(1400) > 350 MeV

Can be explained in terms of - ’ rescattering Constrained by the standard SU(3)L£ SUR(3) £ UA(1) effective lagrangian

: 1(1600), < 200 MeV Currently is being reanalyzed Using 150M (full) event sample (compared to 250K)

1-+ exotic : current status

An Exotic Signal in 3

LeakageFrom

Non-exotic Wavedue to imperfectly

understood acceptance

ExoticSignal

1

Correlation ofPhase

&Intensity

M( ) GeV / c2

BNL (E852) ca 1985

- p ! -+- p

CERN ca. 1970E852 2003Full sample

Software/Hardware from past century is obsolete

BNL

Compare statistics and shapes

28

4

Eve

nts

/50

MeV

/c2

SLAC

SLAC

1.0 2.52.01.5

M(3) GeV / c2

p vs p data

a2

a1

?

Condo’93 p -> + -+ n @ 19.3 GeV Adams ’93 (E852) p -> + -+ p @ 18 GeV

OPE

Photo production enhances exotic mesons

--> (JPC=1--) --> 1(JPC=1-+)

“pluck” the string (S=1,LQQ=0->Lg=1)

1-+ exotic : S=1, L=1

VMD

Condo’93

p -> X+ n

5 GeV

8 GeV

p -> X0 n

18GeV

a2

1

a2

1

1

a2

~ 50% - 100%

10%

In photoproduction

M.Swat, AS

Computational challenge

Step 1 - Reconstruction and Monte Carlo

Reconstruction and

Kinematic Fitting

M.C. data (150M)

MoreFilters

50M 25M

Data (78M) 16M 9M

This involves several hours of M.C.generation and staging of about 1TB of

data to disk and processing Time required: about a weekPerhaps re-done 2 or 3 times

Multiplepasses to

understandcuts

- p ! -+- p

This is the inputto the fitter.

Each time a changeis made to the modelthe inputs must beregenerated

25M

9M

150M

For each eventcompute massesand angles andall invariants and waves thatdepend on massesand angles

Typical # ofamplitudes: 40 or so

240 GB

40 GB

15 GB

Current model

- p ! -+- p

-

p

resonance region

a2,a1,2

,f2,f0,+

-

-

n

Step 2 - Preparing Data and Fits

with the existing software design this can take up to 1 week ! on 100 processors (40 x 80 x 10 = 32000 files)

This is being redesignedin current version this step takes< 1h !

Modern amplitude analysis

AVIDD cluster (Analysis and Visualization of Instrument-Driven Data)

2x208 2.4 GHz Pentium(IUB + IUPUI)

MANTRID

Original E852rp exotic based on0.5M eventsNow processing 10M

36-processor cluster with 1.6Tb of storage

Preliminary results from full E852 sample

a2(1320)2(1670)

Chew’s zero ?

Interference between elementary particle (2) Or the CDD pole with the unitarity cut

Inelastic diffraction : is (1800) a hybrid ?

d/dt = Ae10t

Why Hall D can resolve issues in meson spectrum

• Several orders of magnitude increase in statistics

• “Unlimited” computational resources

• New developments in theory, LGT, EFT

• High energy, intensity, polarized photon beams