Post on 17-Aug-2020
Klaus PetersKlaus PetersRuhrRuhr--UniversitätUniversität BochumBochum
JINR JINR DubnaDubna Workshop, Nov 20, 2003Workshop, Nov 20, 2003
Exotic Hadrons @ PandaExotic Hadrons @ Panda
22 Nov 20, 2003Nov 20, 2003Klaus Peters, U Bochum, Hybrids and GlueballsKlaus Peters, U Bochum, Hybrids and Glueballs
Understanding QCD at small EnergiesUnderstanding QCD at small Energies
Increase precisionmeasure static properties of well known states
Increase the database of decayssearch for unusual decay modes to gain information
Put the hadrons to the limits put the hadrons in vacuum with different baryon density
Excite additional modessearch for gluonic and radial excitations of hadronssearch for gluonic excitation of the strong vacuum
33 Nov 20, 2003Nov 20, 2003Klaus Peters, U Bochum, Hybrids and GlueballsKlaus Peters, U Bochum, Hybrids and Glueballs
Objects of InterestObjects of Interest
Mesons/Baryons
Molecules/Multiquarks
Hybrids
Glueballs
Quark AntiQuark
44 Nov 20, 2003Nov 20, 2003Klaus Peters, U Bochum, Hybrids and GlueballsKlaus Peters, U Bochum, Hybrids and Glueballs
1.0
1.5
2.0
2.5
qq Mesons
L = 0 1 2 3 4
Each box correspondsto 4 nonets (2 for L=0)
Radial excitations
(L = qq angular momentum)
exoticnonets
0–+
0+–
1++
1+–
1–+
1––
2–+
2+–2++
0–+
2–+
0++
Glu
eballs
Hyb
rids
Lattice1-+ 1.9 GeV
Light Meson SpectrumLight Meson Spectrum
0++ 1.6 GeV
55 Nov 20, 2003Nov 20, 2003Klaus Peters, U Bochum, Hybrids and GlueballsKlaus Peters, U Bochum, Hybrids and Glueballs
Hybrid mixing
Glueball mixing
Level MixingLevel Mixing
Light quark problemthe mixing
Mixingbroad stateshigh level density
I=1 I=0nn I=0ss I=½
a1 f1 f1’ K1B
b1 h1 h1’ K1A
JPC=JP+
JPC=JP-
Kaon mixingstrong interaction C undefined K1A-K1B
Isoscalar mixingstrong interaction IG, JPC identical ?-?‘
Isospin mixingelm interaction ? I=1 ?-?
66 Nov 20, 2003Nov 20, 2003Klaus Peters, U Bochum, Hybrids and GlueballsKlaus Peters, U Bochum, Hybrids and Glueballs
Level MixingLevel Mixing
Light quark problemthe mixing
Mixingbroad stateshigh level density
Better:narrow states
and/or lower level densitycharmed systems !
Exo
tic
light
Exo
tic
cc
1-- 1-+
0 2000 4000MeV/c2
10-2
1
102
77 Nov 20, 2003Nov 20, 2003Klaus Peters, U Bochum, Hybrids and GlueballsKlaus Peters, U Bochum, Hybrids and Glueballs
Σ
Π
Charmed HybridsCharmed Hybrids
LQCD: gluonic excitations of the quark-antiquark-potential may lead to bound statesΣ-potential
for one-gluon exchangeΠ-potential
from excited gluon flux
mHcc ~ 4.2-4.5 GeV/c2
Light charmed hybrids could be narrow if open charm decays are inaccessible or suppressed
Σ
Π
important <r2> and rBreakup
3
3.5
4
1 2
R/r0
V(R)/GeV
J/?
?c
? ‘
Hcc
DD
88 Nov 20, 2003Nov 20, 2003Klaus Peters, U Bochum, Hybrids and GlueballsKlaus Peters, U Bochum, Hybrids and Glueballs
S1
S2
S=S1+S2
J=L+S
P=(-1)L+1
C=(-1)L+S
L
Simplest HybridsSimplest Hybrids
S-Wave+Gluon (qq)8g with ()8=coloured1S0 ↑↓ 3S1 ↑↑ combined with a 1+ or 1- gluon
2–+2+-
1–+1+-
0–+0+-3S1, 1––
1––1++1S0, 0–+
1+(TE)1– (TM)Gluon
Exotic JPC cannot! be formed by qq
99 Nov 20, 2003Nov 20, 2003Klaus Peters, U Bochum, Hybrids and GlueballsKlaus Peters, U Bochum, Hybrids and Glueballs
LQCD LQCD ccccgg 11--++ vs. cvs. ccc 11---- (J/(J/ψψ))
NPB93Supp(1999)264MILC99isotropic150±4317
PRL82(1999)4400JKM99isotropic4287
±
±
±
±
37
130
150
80
m(ccg)- m(cc)
37
80
m(ccg)
hep-lat 0206012ZSU02anisotropic99±1302
PRL82(1999)4400JKM99isotropic1190
PRL82(1999)4396CP-PACS99anisotropic±1323
NPB93Supp(1999)264MILC99isotropic±1220
PRD56(1997)7039MILC97isotropic200±1340
∆(1-+,1--)
hep-lat 0206012ZSU02anisotropic99±4369
PRD56(1997)7039MILC97isotropic200±4390
ReferenceGroupModel1-+
1010 Nov 20, 2003Nov 20, 2003Klaus Peters, U Bochum, Hybrids and GlueballsKlaus Peters, U Bochum, Hybrids and Glueballs
Charmed Hybrid Level SchemeCharmed Hybrid Level Scheme
1-- (0,1,2)-+ < 1++ (0,1,2)+-
JKM, NPB 83suppl(2000)304 and Manke, PRD57(1998)3829
L-Splitting?m ~ 100-250 MeV/c2
for 1-+ to 0+-
S-SplittingsPage thesis,1995 and PRD 35(1987)16684.14 (0-+) to 4.52 GeV/c2 (2-+)
consistent w/LQCDJKM, NPB 86suppl(2000)397, PLB478(2000) 151
0-+ 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**
1111 Nov 20, 2003Nov 20, 2003Klaus Peters, U Bochum, Hybrids and GlueballsKlaus Peters, U Bochum, Hybrids and Glueballs
FluxtubeFluxtube
Meson
Hybrid
~ Simplified Lattice Approach
Flux (excited Gluon) carries angular momentumBali, priv. comm., 1991
1212 Nov 20, 2003Nov 20, 2003Klaus Peters, U Bochum, Hybrids and GlueballsKlaus Peters, U Bochum, Hybrids and Glueballs
Charmed Hybrids Charmed Hybrids –– DecaysDecays
Fluxtube-Model predicts DD**(+c.c.) decaysif mH< 4290 MeV/c2 below DD0(+c.c.)
→ ΓH < 50 MeV/c2
Some exotics can decay neither to DD nor to DD*(+c.c.)
e.g.: JPC(H)=0+-
J/? f2, J/? (pp)S, ?ch1
χc0ω, χc0φ, χc2ω, χc2φ, h1c?Small 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
1313 Nov 20, 2003Nov 20, 2003Klaus Peters, U Bochum, Hybrids and GlueballsKlaus Peters, U Bochum, Hybrids and Glueballs
Charmed Hybrids Charmed Hybrids –– Decays of 1Decays of 1--++
a very likely decay mode will (could?) be χc(pp)S
aC. Michael, hep-lat 0207017preferably using p0p0 to avoid ?(770) contaminationuse charged mode p+p- for comparison
detect the χc in the radiative decay to J/?
detect the soft photonand the lepton pair
NeededSerious calculations for production and partial decay widths for ccg
1414 Nov 20, 2003Nov 20, 2003Klaus Peters, U Bochum, Hybrids and GlueballsKlaus Peters, U Bochum, Hybrids and Glueballs
ProtonProton--Antiproton AnnihilationAntiproton Annihilation
Production all JPC available
Formation only selected JPC
p
p recoil
p
p
1515 Nov 20, 2003Nov 20, 2003Klaus Peters, U Bochum, Hybrids and GlueballsKlaus Peters, U Bochum, Hybrids and Glueballs
Formation
ProtonProton--Antiproton AnnihilationAntiproton Annihilation
Gluon rich process creates gluonic excitation directlyss/cc requires the quarks to annihilate (no rearrangement)yield comparable to charmonium productioneven at low momenta large exotic content has been proven
G
M
p
p
G
p
p
Production all JPC available
only selected JPC
p
p
H
nng
H
p
p ssg/ccg
M
p
p
H
nng
M
Hp
p
ssg/ccg
1616 Nov 20, 2003Nov 20, 2003Klaus Peters, U Bochum, Hybrids and GlueballsKlaus Peters, U Bochum, Hybrids and Glueballs
Heavy GlueballsHeavy Glueballs
Light gg/ggg-systems are complicated to identify (mixing!)Exotic heavy glueballs
m(0+-) = 4140(50)(200) MeVm(2+-) = 4740(70)(230) MeV
Width unknown, but!nature invests more likely in mass than in momentumnewest proof: double cc yield in e+e-
Flavour-blindnesspredicts decays into charmed final states too
Same run period as hybridsIn addition: scan m>2 GeV/c2
Morningstar,Peardon, PRD60(1999)34509Morningstar,Peardon, PRD56(1997)4043
2++
0+-
2+-
1717 Nov 20, 2003Nov 20, 2003Klaus Peters, U Bochum, Hybrids and GlueballsKlaus Peters, U Bochum, Hybrids and Glueballs
44--Quark FormationQuark Formation
Proton-Antiproton contains already a 4-Quark-System
Idea: Dilepton-Tag from Drell-Yan-Production
AdvantagesTriggerless JPC-Ambiguities1200 E./day @ 12 GeV300 E./day @ 5-8 GeVantiproton-Beam(for L=1032cm-2s-1)
Bannikov, Gornuschkin, Kopeliovich, Krumshteinand Sapozhnikov, JINR E1-92-344 (1992)
1818 Nov 20, 2003Nov 20, 2003Klaus Peters, U Bochum, Hybrids and GlueballsKlaus Peters, U Bochum, Hybrids and Glueballs
TT + + @ @ variousvarious experimentsexperimentsLEPS(SPRingLEPS(SPRing--8), 8), Diana(ITEPDiana(ITEP), ), Clas(JLABClas(JLAB) ) Saphir (Elsa)Saphir (Elsa)
1919 Nov 20, 2003Nov 20, 2003Klaus Peters, U Bochum, Hybrids and GlueballsKlaus Peters, U Bochum, Hybrids and Glueballs
PentaQuarkPentaQuark PicturePicture
In a multi quark picturenK+ has an anti-strange quark and several light quarkspKS has no defined strangeness and thus only a supporting evidence
Jaffe-Wilczek pictureAnti-quark act as a junction between two diquarks
Basic ideaReplace the anti-quark by other anti-quarks – like anti-charmseveral quark combinations for each charge
T C-- |cdddd>, |cssss>
T C- |cuddd>, |cudds>, |cudss>, |cusss>
T C0 |cuudd>, |cuuds>, |cuuss>
T C+ |cuuud>, |cuuus>
T C++ |cuuuu>
plus all isomeres
Jaffe & Wilczek hep-ph/0307341Karliner & Lipkin hep-ph/0307343
2020 Nov 20, 2003Nov 20, 2003Klaus Peters, U Bochum, Hybrids and GlueballsKlaus Peters, U Bochum, Hybrids and Glueballs
TT CC00 ||ccuudduudd>, |>, |ccuudsuuds>, |>, |ccuussuuss>>
Is the most discussed anti-charm penta-quark|cuudd> would decay to ND final states like nD0 or pD-
problematic below the ND threshold of ~2.8 GeV/c2
(many weak channels NKX possible, signature unclear)|cuuds> would decay to pDS
-
but also below the open charm threshold (~2.91 GeV/c2) there is the clean channel pφπ- which would also be used for the pDS
-
selection|cuuss> would decay to S+DS
- and ?0D0
but also below the open charm threshold (~3.15 GeV/c2) there is the clean channel S+φp- which would also be used for the S+DS
- selection.(there are some other weak channels with ?KX with unclear signature)
Implies uncooled p beam or formation with Fermi-momentumon a nuclear target
2121 Nov 20, 2003Nov 20, 2003Klaus Peters, U Bochum, Hybrids and GlueballsKlaus Peters, U Bochum, Hybrids and Glueballs
Exotics in ProtonExotics in Proton--AntiprotonAntiproton
Exotics are heavily produced in pp reactions
High production yields for exotic mesons (or with a large fraction of it)
f0(1500)p → ~25 % in 3p0
f0(1500)p → ~25 % in 2?p0
p1(1400)p → >10 % in p±p0?
Interference with other well known (conventional) states is mandatory for the phase analysis
Crystal Barrel
2222 Nov 20, 2003Nov 20, 2003Klaus Peters, U Bochum, Hybrids and GlueballsKlaus Peters, U Bochum, Hybrids and Glueballs
0 2 4 6 8 12 1510p Momentum [GeV/c]
Mass [GeV/c2]
Two bodythresholds
Molecules
GluonicExcitations
qq Mesons
1 2 3 4 5 6
Hybrids
Hybrids+Recoil
Glueball
Glueball+Recoil
??SS??
? c? cScSc? c?c
OcOcOO DDDsDs
qqqq ccqq
nng,ssg ccg
ggg,gg
light qqp,?,? ,f2,K,K*
ccJ/? , ?c, ?cJ
nng,ssg ccg
ggg
Accessible Hadrons at PANDA @ GSIAccessible Hadrons at PANDA @ GSI
conventionalcharmonium
exoticcharmonium
Charmed states
2323 Nov 20, 2003Nov 20, 2003Klaus Peters, U Bochum, Hybrids and GlueballsKlaus Peters, U Bochum, Hybrids and Glueballs
0 2 4 6 8 12 1510p Momentum [GeV/c]
Mass [GeV/c2]
Two bodythresholds
Molecules
GluonicExcitations
qq Mesons
1 2 3 4 5 6
Hybrids
Hybrids+Recoil
Glueball
Glueball+Recoil
??SS??
? c? cScSc? c?c
OcOcOO DDDsDs
qqqq ccqq
nng,ssg ccg
ggg,gg
light qqp,?,? ,f2,K,K*
ccJ/? , ?c, ?cJ
nng,ssg ccg
ggg
Accessible Hadrons at PANDA @ GSIAccessible Hadrons at PANDA @ GSI
Other exotics with identical decay channels → same region
glueballs
Glueballs
2424 Nov 20, 2003Nov 20, 2003Klaus Peters, U Bochum, Hybrids and GlueballsKlaus Peters, U Bochum, Hybrids and Glueballs
Lessons from LEARLessons from LEAR
Eγ
3π0
Emin
cosθ
Full solid angleno missing particles (photons!)no “dead” regions
Merged p0 are easy to handle“moderate” angular resolution sufficient
Low thresholdsEmin~20 MeV in theelectromagnetic detector
φ (φ)-Tagφφ and recoil φ
K-Trigger/K-IdKS-TriggerKaon ID @ high energies
2525 Nov 20, 2003Nov 20, 2003Klaus Peters, U Bochum, Hybrids and GlueballsKlaus Peters, U Bochum, Hybrids and Glueballs
It’s All a Question of Statistics ...It’s All a Question of Statistics ...
pp → 3p0
with100 events
2626 Nov 20, 2003Nov 20, 2003Klaus Peters, U Bochum, Hybrids and GlueballsKlaus Peters, U Bochum, Hybrids and Glueballs
It’s All a Question of Statistics ... ...It’s All a Question of Statistics ... ...
pp → 3p0
with100 events1000 events
2727 Nov 20, 2003Nov 20, 2003Klaus Peters, U Bochum, Hybrids and GlueballsKlaus Peters, U Bochum, Hybrids and Glueballs
It’s All a Question of Statistics ... ... ...It’s All a Question of Statistics ... ... ...
pp → 3p0
with100 events1000 events10000 events
2828 Nov 20, 2003Nov 20, 2003Klaus Peters, U Bochum, Hybrids and GlueballsKlaus Peters, U Bochum, Hybrids and Glueballs
It’s All a Question of Statistics ... ... ... ...It’s All a Question of Statistics ... ... ... ...
pp → 3p0
with100 events1000 events10000 events100000 events
2929 Nov 20, 2003Nov 20, 2003Klaus Peters, U Bochum, Hybrids and GlueballsKlaus Peters, U Bochum, Hybrids and Glueballs
pp in Flight in Flight –– no longer a challenge!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 dramaticallyalternative: integration of the production process
Peters, NPA 692(2001)295
3030 Nov 20, 2003Nov 20, 2003Klaus Peters, U Bochum, Hybrids and GlueballsKlaus Peters, U Bochum, Hybrids and Glueballs
Summary & OutlookSummary & Outlook
Investigation of exotics is thekey tool for the investigation ofgluonic degrees of freedom inside hadrons
Panda@HESR will survey the mass region from ~2 to more than 4 GeV/c2 in formation and production processes ...
... to measure the whole spectrum of heavy exotics