Klaus Peters Ruhr-Universität Bochum Yokohama, March 3, 2003 Charmed Hybrids @

Klaus PetersKlaus PetersRuhr-Universität BochumRuhr-Universität Bochum

Yokohama, March 3, 2003Yokohama, March 3, 2003

Charmed Hybrids @

22 March 3, 2003March 3, 2003Klaus Peters, U Bochum, Charmed Hybrids in Proton AntiprotonKlaus Peters, U Bochum, Charmed Hybrids in Proton Antiproton

OverviewOverview

Phenomenology of HybridsCharmed Hybrid SpectrumExperimental techniquesConclusions

see also Helmut Koch’s talk on Hadron physics with Panda

see also Ted Barnes’ talk on Testing QCD – from LEAR to GSI

see also Walter Henning’s talk on The GSI Future Project


Standard model meson only one leading term

Other colour neutral configurations may mix

Decoupling is possible only if

states are narrowlower density of statesleading term vanishes

Ex

oti

c lig

ht

qq

Ex

oti

c cc

1 - - 1 - +

0 2 0 0 0 4 0 0 0M e V / c2

10 - 2

1

1 0 2

Hadrons are very complicatedHadrons are very complicated

qq

(q )(q )q q

+

(q )gq

+

gg

+

= (q ) gi i j jq

+........


Simplest HybridsSimplest Hybrids

S-Wave+Gluon (qq)8g with ()8=coloured1S0 3S1

combined with a 1+ or 1- gluon

Gluon 1–– (TM) 1+– (TE)

1S0, 0–+ 1+– 1––

3S1, 1–– 0++ 0–+

1++ 1–+

2++ 2–+

Meson – Hybrid Mixing

gMIX

gFSI

q

q


Charmed HybridsCharmed Hybrids

Gluonic excitations of the quark-antiquark-potential may lead to bound states

LQCD: -potentialmH ~ 4.2-4.5 GeV

Light charmed hybrids could be as narrow as O(5-50 MeV)

important <r2> and rBreakup


LQCD cLQCD cccg 1g 1-+-+ vs. c vs. ccc 1 1---- (J/ (J/))

1-+ m(ccg) Model Group Reference

4390 ±80 ±200 isotropic MILC97 PRD56(1997)7039

4317 ±150 isotropic MILC99 NPB93Supp(1999)264

4287 isotropic JKM99 PRL82(1999)4400

4369 ±37 ±99 anisotropic ZSU02 hep-lat 0206012

(1-+,1--) m(ccg)- m(cc)

1340 ±80 ±200 isotropic MILC97 PRD56(1997)7039

1220 ±150 isotropic MILC99 NPB93Supp(1999)264

1323 ±130 anisotropic CP-PACS99 PRL82(1999)4396

1190 isotropic JKM99 PRL82(1999)4400

1302 ±37 ±99 anisotropic ZSU02 hep-lat 0206012


Charmed Hybrid Level SchemeCharmed Hybrid Level Scheme

1-- (0,1,2)-+ < 1++ (0,1,2)+-

JKM00, NPB83Suppl83(2000)304 and Manke, PRD57(1998)3829

L-Splittingm ~ 100-250 MeV/c2

for 1-+ to 0+-

S-Splittings Page thesis,1995 and

PRD35(1987)16684.14 (0-+ ) to 4.52 GeV/c2 (2-+)

consistent w/LQCDJKM, NPB86suppl(2000)397,

PLB478(2000) 1510-+ 4.14

1-+ 4.37

2-+ 4.52

1-- 4.48

4.1

4.2

4.3

4.4

4.5

4.6

4.7

4.8

0+- 4.47

1+- 4.70

2+- 4.85

1++ 4.81

DD**


FluxtubeFluxtube

Meson

Hybrid

~ Simplified Lattice Approach

Flux (excited Gluon) carries angular momentum


Charmed Hybrids – DecaysCharmed Hybrids – Decays

Fluxtube-Model predicts DD**(+c.c.) decaysif mH<4290 MeV/c2 below DD0(+c.c.)

H < 50 MeV/c2

Some exotics can decay neither to DD nor to DD*(+c.c.)

e.g.: JPC(H)=0+-

• fluxtube forbidden: J/f2, J/()S, ch1

• fluxtube allowed: c0, c0, c2, c2, h1cSmall number of final states with small phase space

• favours a narrow resonanceif DD**(+c.c.) possible still very small phase space

But! be prepared for surprisesmeasure DD nor to DD*(+c.c.) waves as well


Charmed Hybrids – Decays of 1Charmed Hybrids – Decays of 1-+-+

a very likely decay mode will (could?) be c()S

ano DD**(+c.c.) needed and fluxtube allowedC. Michael, hep-lat 0207017preferably using 00 to avoid (770) contaminationuse charged mode +- for comparison

detect the c in the radiative decay to J/

detect the soft photonand the lepton pair


Proton-Antiproton @ Rest/FlightProton-Antiproton @ Rest/Flight

Production

all JPC available

Formation

only selected JPC

see also Diego Bettoni’s talk on Charmonium Production


Proton-Antiproton @ Rest/FlightProton-Antiproton @ Rest/Flight

Gluon rich process creates gluonic excitation in a direct waycc requires the quarks to annihilate (no rearrangement)yield comparable to charmonium productioneven at low momenta large exotic content has been proven

Momentum range for a survey pp ~15 GeV

p

p_

G

M

p

M

H

p_

p

M

H

p_

p

p_

G

p

p_

H

p

p_

H

Production

all JPC available

Formation

only selected JPC


Accessible HadronsAccessible Hadrons

Other exotics with identical decay channels same region

mass and phase spaceof recoil meson forexotic JPC included


Signatures, Potential ProblemsSignatures, Potential Problems

“Leading charmonia”J/, ‘, (‘)

c, cj, [DD] a.o.m.?

DiLeptonse+e- (Ecal,Trk)+- (Trk,Hcal)

()-Tag and recoil (Trk,Cherenkov)

KS (+K±)-Tagc and hc (Vtx,Trk,Cherenkov)

Photon-Pairs from cc (Ecal,no-Trk)from 0 and (Ecal)

Many information needed on “trigger” level !

see also Jim Ritman’s talk on Detector concepts for Panda


pp in Flight – no longer a challenge! in Flight – no longer a challenge!

Crystal Barrel provedannihilation in flight can be

analyzed unambiguously

Formation:two body decays, where at

least one particle carries spin!~10k events L up to 6

Production:small recoil momenta reduce

the available phase space and the contributing waves dramatically

alternative: integration of the production process

Peters, NPA 692(2001)295


Summary & OutlookSummary & Outlook

Investigation of charmed hybrids isthe key tool to the investigation ofgluonic degrees of freedom inside hadrons

HESR @ GSI will survey the whole ccg mass region in formation and production processes ...

... to measure the whole spectrum of charmed hybrids

Klaus Peters Ruhr-Universität Bochum Yokohama, March 3, 2003 Charmed Hybrids @

Documents

Transcript of Klaus Peters Ruhr-Universität Bochum Yokohama, March 3, 2003 Charmed Hybrids @