Hierarchies of MatterHierarchies of Matter

matter

crystal

atom

atomic nucleus

nucleon

quarks

10-9 m

10-10 m

10-14 m

10-15 m

< 10-18 m

(macroscopic)

• confinement

• hadron masses

general features: constituents observed as

free particles

ii

m m

nucleon: constituents (quarks) not observed as free particles

ii

m m

Hadron PhysicsHadron Physics

• How are hadrons (baryons and mesons) built from quarks and gluons ?

• Can we quantitatively account for the confinement of quarks and gluons inside hadrons ?

e.g., nucleon mass ?

• J/ spectroscopy confinement

• glueballs (ggg) and hybrids (ccg)

• hidden and open charm mesons in nuclei

• hypernuclei

Physics program at the HESRPhysics program at the HESR

Further possibilities:

• Inverted Deeply Virtual Compton Scattering

• CP-violation (D/-sector)

• fundamental symmetries; p in traps

The GSI p - FacilityThe GSI p - Facility

p production with 29 GeV p-beam p production rate: 107/s

p-stored in the HESR: (High Energy Storage Ring) p-momentum: 1.5 - 15 GeV/c

Nstored: 5 • 1010 pHigh luminosity mode L 2 • 1032 cm-2s-1 p/p 10-4 (stochastic cooling)High resolution mode

L 1031 cm-2s-1 p/p 10-5 (e–- cooling)

Quantumelectrodynamics (QED)Quantumelectrodynamics (QED) Quantumchromodynamics (QCD)Quantumchromodynamics (QCD)

r

crV

rV

r

rKr

c

3

4rV S

rforrV

confinement potential

rV

Masse / MeV

2900

3100

3300

3500

3700

3900

4100

3730DD

)3097(

)3686(')3770(''

)4040('''

)3525(hc )3510(1)3556(2

)3415(0

)3590('c

)2980(c

1D23D2

3P0(~3800)3P1(~3880)

3P2(~3940)

terra incognita

cc

Charmonium

1fm

Charmonium ( c c )Positronium (e+e–)

ionisation energy

binding energy meV

0

-1000

-3000

-5000

-7000

e e

Positronium

0.1nm1S0

1S0

1S0

3S1

3S11P1 3P1

3P0

3P2

comparison e+e¯ versus ppcomparison e+e¯ versus pp

e+e- interactions: only 1-- states formed other states populated in secondary decays (moderate mass resolution)

pp reactions: all states directly formed (very good mass resolution)

production of 1,2

'ee

2,1

/J ee

formation of 1,2

/J ee

2,1pp

Crystall Ball

E 760 (Fermilab)

m (beam) = 0.5 MeV

GlueballsGlueballs

characteristic feature of QCD self-interaction among gluons

predicted masses: 1.5 - 5.0 GeV/c2

candidate: f0(1500): 0++; =110MeV no flavour blind decay

mixing with neighbouring scalar meson states

search for higher lying glueball states

mixing with (qq) and (QQ) excluded for exotic states

mixing with (QQ) small

width 100 MeV

charmed hybrids (ccg)charmed hybrids (ccg)

predicted masses: 3.9 - 4.5 GeV/c2

lowest state: JPC = 1–+ (exotic)

width: could be narrow (LGT: 10 MeV)

forbidden decays:

e.g. O+– DD, D*D*, DSDS (CP-violation)(QQg) (Qq)L=0 + (Qq)L=0 (dynamic selection rule)

below 4.3 GeV/c2 no decay into DD

preferred decays:

(ccg) (cc) + X

e.g. 1+– J/ + , ,

in-medium modification of mesons

in-medium modification of mesons study of chiral symmetry

restoration in the charm sector

Open Charm in NucleiOpen Charm in Nuclei

Consequence of dropping D-meson mass in the medium:

strong enhancement of D-meson cross section in near/sub-threshold region

probing D-meson properties at ground state nuclear matter density and T 0 (complementary to heavy ion collisions)

J/ - nucleon interactionJ/ - nucleon interaction

• J/ - suppression regarded as signature for the generation of the quark-gluon plasma in ultra-relativistic nucleus-nucleus collisions

• suppression due to purely hadronic interactions?

measure N-J/ cross section in nuclear matter

)1A(/JAp

Str

ange

sess

Neutron Number

three-dimensional nuclear chart with strangeness degree of freedomthree-dimensional nuclear chart

with strangeness degree of freedom

Double Hypernucleus SpectroscopyDouble Hypernucleus Spectroscopy

double hypernuclens productiondouble hypernuclens production detector schemedetector scheme

¯(dss) p(uud) (uds) (uds) rates: applying K-trigger: 3 • 105 stopped ¯ / d

detected -transitions: 100 / d

keV-resolution !!

layout of proposed new GSI facilitylayout of proposed new GSI facilityp-beam

p-beam

synergy effect: parallel operation of physics programssynergy effect: parallel operation of physics programs

ConclusionConclusion

• The interaction of cooled antiproton beams with nucleons and nuclei opens up a broad and challenging research program ranging from non-perturbative QCD – phenomena (glueballs, hybrids, confinement, chiral symmetry breaking) to CP-violation and tests of fundamental symmetries.

• High luminosity and monochromaticity at HESR will provide high precision data and sensitivity to rare processes.

• Electron-cooling in the HESR is a technological challenge.

• With the realisation of the HESR as integral part of the future accelerator facility, GSI will play a pioneering role in the experimental exploration of long-distance (non-perturbative) QCD and the structure of hadronic matter.