hadron physics with antiprotons - panda experiment · 2006. 1. 9. · h. koch, leap03, yokohama,...

H. Koch, LEAP03, Yokohama, March 3-7, 2003

Hadron Physics with Antiprotons

– Introduction

– HESR/PANDA - Project at GSI (→ W. Henning)

– Merits of experiments with antiprotons

– Physics Program

Charmonium Spectroscopy (→ D. Bettoni)

Heavier Glueballs and charmed Hybrids (→ K. Peters)

Hadrons in Nuclear Matter (→ W. Henning)

Double Hypernuclei (→ J. Pochodzalla)

Further Options:

Low energy beams, Open Charm production, CP-Violation, Inverted Deeply Virtual

Compton Scattering (→ P. Kienle, Poster H. Koch, S. Ganzhur)

– Status of the Project

– Conclusions


Introduction

Open problems in non-perturbative QCD

Confinement

Violation of chiral symmetry

Masses of Hadrons

Important : Gluonic degrees of freedom

Layout of proposed new GSI facility

p-beam

p-beam



HESR (High Energy Storage Ring)p production with 29 GeV p-beam

p production rate : 107/s

p-stored in the HESR, Fixed Target (ECM ≤ 5.5 GeV)

p-momentum : 1.5-15 GeV/c

Np-stored : 5 1010

High luminosity mode

L ≈ 2 1032 cm-2s-1

δp/p ≈ 10-4 (stochastic cooling)

High resolution mode

L ≈ 1031 cm-2s-1

δp/p ≈ 10-5 (e–- cooling)

BILD fehltWoher ?

PANDA-Detector

The PANDA detector

Detector features:

• tracking of charged particles• measurement and identification of g, e±, m±, p±, K±, p, p• high rate capability• sophisticated and fast trigger scheme


PANDA – DetectorDetector requests– Nearly full solid angle for charged particles and Gammas

– High rate capability

– Good particle identification (e, µ, π, K, p)

– Efficient trigger on e, µ, K, D

General purpose detector– Target: Jet/Pellet/Wire

– Tracking: Pixels (MVD) / Straws / Mini-Drift-Chambers (MDC)

– E.M. Calorimeter: PbWO4, APD-Readout

– Muons: Plastic Scint. Strips

– PID: Aerogel Cerenkov (ACC) / DIRC

– Trigger: High p⊥ electrons/muons / Multiplicity jump (KS, Λ, …)

Secondary vertex (D’s,…) / Invariant masses / Global kinematical conditions

0

QCD systems to be studied at HESRQCD systems to be studied at HESR

N 2S+1LJ

1 1S0

1 3S1

1 1P1

1 3P0

1 3P1

1 3P2

1 1D2

1 3D1

1 3D2

1 3D3

1 3F4

2 1S0

2 3S1

2 3P2

3 1S0

JPC

0–+

1––

1+–

0++

1++

2++

2–+

1––

2––

3––

4++

0–+

1––

2++

0–+

I = 1

π

ρ

b1(1235)

a0(1450)∗

a1(1260)

a2(1320)

π2(1670)

ρ(1700)

ρ3(1690)

a4(2040)

π(1300)

ρ(1450)

π(1800)

I = 0

η, ηη'

ω, φφ

h1(1170), h1(1380)

f0(1370)∗ , f0(1710)∗

f1(1285), f1(1420)

f2(1270), f2'(1525)

η2(1645), η2(1870)

ω(1650)

ω3(1670), φφ3(1850)

f4(2050), f4(2220)

η(1295), ηη(1440)

ω(1420), φφ(1680)

f2(1810), f2(2010)

η(1760)

I = 1/2

K

K*(892)

K1B†

K0*(1430)

K1A†

K2*(1430)

K2(1770)

K*(1680)‡

K2(1820)

K3* (1780)

K4*(2045)

K(1460)

K*(1410)‡

K2* (1980)

K(1830)

ud, uu, dd uu, dd, ss su, sd

Review of Particle Physics 2000

contributions from LEAR experiments



HESR / PANDA

Production Rates (1-2 (fb)-1/y)

Final StateMeson resonance anything b

b

A b

DD nb

J e e nb

J nb

nb

nb

c c

c c

+

→

→→ +

+ +

100 10

50 10

2 10 10

250 10

630 10

3 7 10

20 10

0 1 10

10

10

8 5

7

9

2 7

7

5

µµµ

ψ µ µχ ψ γ

ΛΛΞ Ξ

Λ ΛΩ Ω

ΛΛ( ) ( )

/ ( , )

( / ) .

.

– –

cross section # reconstr. events/y

Common Feature : Low multiplicity events Moderate particle energiesFor Pairs : Charge symmetric conditions Trigger on one, investigate the other


Merits of experiments with Antiprotons

– High cross sections

Facilitates search for rare particles (Glueball Groundstate)– Most particles can be directly created in formation processes regardless of

their JPC quantum numbers (cc-spectroscopy)

– Exotic states are produced with rates similar to qq, qqq-systems (Glueball-,

Hybrid candidates)

– (Cooled) beams have small ∆p/p and small emittances

Clean experimental conditions– p-induced reactions (≤ 15 GeV) have low particle multiplities

Reconstruction of full events, Reliable PWA

0

0

1

1

2

2

3 GeV2

3

mποπο2

mπο

πο2

712,000 eventspp → ποποπο (at rest)

f2(1565)

mηπο2

mηπ

ο2

0.6

0.6

0.8

1.0

1.2

1.4

1.6

0.8 1.0 1.2 1.4 1.6 GeV2

pp → ποηη (at rest)

m2(π0 KLmiss)

m2( π

0K

Lseen

)

0.4

0.6

0.8

1

1.2

1.4

1.8

2

0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 GeV2

fo (1500)• K

LK

L

pp • πoKLK

L

37.500 events

1.2 1.3 1.4 1.5 1.6 1.7 GeV2

2.4

2.6

2.8

3.0

M2πη’

M2 ηη

’

f0(1500)

pp π°ηη'pp 5 π°

Phase

Spac

e

1000 1200 1400 1600

2000

4000

6000

CB Data

M4πο




e+e–- collisions: Only 1– – -states are directly formed (Well measured, e– e+ energy scans) The other states only visible through secondary reactions, e.g.: e+e– → ψ’ → χ + γ (moderate mass resolution)pp - collisions: All states can be directly formed (Very good mass resolution, scans with p)

Charmonium - States



p d X p X XStop ( ) , ( ) , ; ( )→ + + → → ′−+ −1 1400 16000π ηπ ηπ πηGeneral observations

– High Statistics data needed

– Exotics couple to pp with a strength similar to qq-states

(Established by BNL; First hints: VES, GAMS)

1 32

a2(1320)

π1(1400)

mπη [GeV2/c4]2

Num

ber

of e

vent

s

LEAR : Spin Exotics

Decay: (ηπ)L=1

Mass: 1400 ± 30 MeV

Width: 310 ± 70 MeV

Quantum Numbers: JPC = 1–+ (I =1)

not possible from qq

Properties of the ρ(1400)

Previous indications of this resonance:

P = (–)L+1

C = (–)L+S

J = L + S

π–p (π η)n (GAMS/CERN, 100 GeV/c, 1988)π–p (π η)n (VES/Serpukhov, 100 GeV/c, 1993)π–p (π η)n (E852/Brookhaven, 18 GeV/c, 1997)

M: 1300 – 1400 MeV, G: 150 – 400 MeV


A second exotic particle (JPC=1–+)

Crystal Barrel:

pp π+π–η'

π1(1600): M = 1563 ± 30 MeV/c2Γ = 195 ± 50 MeV/c2

preliminary, LEAP2000 conference

BNL (E852):

π–p ρπ–p

π1(1600): M = 1593 ± 8 MeV/c2Γ = 168 ± 20 MeV/c2

Phys. Rev. Lett. 81 (1998) 5760


preliminary, Joerg Reinhardt, Bonn

()S a2(1320) a0(1450) 1 lnL

(1585,160)

22.72 77.28 - - - 164.2

18.68 80.78 0.53 - - 158.31

33.75 40.35 0.01 25.9 - 134.1

24.26 64.0 1.23 2.39 8.04 126.63

22.72 77.28 - - - 164.2

18.68 80.78 0.53 - - 158.31

27.15 64.7 1.33 - 6.82 127.83

24.26 64.0 1.23 2.39 8.04 126.63

(1567.7,158.2)

26.93 64.5 1.28 - 7.08 127.28

(1563,195.0)

23.64 61.3 1.24 3.76 10.1 125.86

Fit of Dalitz plot



~ 900 events in 1 year of running

Meson production in Ds decays with BABAR

Indications for a J/ψφ resonances?

BABAR can expect ~300 events within 5 years.

M2 (J

/)(

GeV

2 /c4 )

M2( K)(GeV2/c4)

2031099-00424.0

2.016.0

17.0

18.0

19.0

20.0

21.0

22.0

23.0

5.04.54.03.53.02.5

4.35 GeV/c24.5 GeV/c2

New Results from CLEO

Phys. Rev. Lett. 84, 1393 (2000)

B J/ψφK

4.7 GeV/c2



Physics Program / Charmonium Spectroscopy

Energies/Energy splittings/Widths of states

Details of QQ-interactions

Confinement Potential

Exclusive Decays

Mixing of perturbative/non-pert. effects

cc - system (QCD) e+e–-system (QED)=


Physics Program / Charmonium SpectroscopyExperimental situation

R704 (CERN/ISR) / E760/835 (Fermilab) Discovery of hc (1P1) - state Very precise values for masses and withs of χc, ηc-states Measurement of previously unknown branching ratios Determination of αs (mc)

e.g. / ; , (Hadron helicity non conserving process)/ , , (G parity violating decays)

, ... (Radiative decays), , , , (Higher Fock state contributions)

c co

cJ

J BBJ

ψ ρπ η χψ π π ωπ ρη

ψ γ π η ψχ ρρ φφ ρη ρη η η

→ →→ −

′ → + ′−→ ′ ′ ′

+ −

0

0

But : Severe limitations (Non magnetic detector, beamtime, beam momentum reproducibility, ...)

– ηc‘ (Cball) not yet established (Spin-Spin-Interaction)– 1P1 (E760) unconfirmed– D-wave states (some of them very narrow) and radially P-states not fully understood (Structure of states)– Angular distributions of radiative decays not understood (Mixing of pert./non-pert. Effects)

Many questions left open:


Physics Program / Charmed Hybrids

Predictions: (LQCD, Bag-Model, Flux-Tube-Model,…)

Masses Lowest energy states: 3.9-4.5 GeV/c2

Ground state: JPC = 1–+ (spin-exotic)

Widths

Could be narrow in some cases (≈MeV)

Charmed Hybrids : (ccg)


Physics Program / Charmed Hybrids

High chances to find charmed hybrids

Less mixing than in (qqg)-sector

Measuring program at HESRStates with non exotic q.-n.:

p-scan: pp → (ccg) 3.9 - 4.3 GeV/c2 ; J/ψ-trigger) pp → (ccg) (4.3 - 5.0 GeV/c2 ; D-trigger),

≈ 104 (ccg) → J/ψ + η per day (Decay channel selects q.-n.)

States with exotic q.-n.:

Production experiment:

≈ 102 (ccg) per day, PWA of Dalitz-Plots (see LEAR)

In addition: Measuring program on light hybrids ≈ 2 GeV/c2, Scan- and production mode

Favorite channels:

Large cross sections (µb), Complementary to Hall D

pp ccg→ +( ) ( )π η0

J / , ,ψ ω φγ+

pp ccg f K K→ →( ) ( ) , , ...1 11285 π


Physics Program / Heavier Glueballs

Predictions:Masses:

1.5-5.0 GeV/c2 (Ground state found? ;

Candidates for further states?)

Quantum numbers:

Several spin exotics (oddballs), e.g.

JPC = 2+- (4.3 GeV/c2 )

Widths: ≥ 100 MeV/c2

– Decay into two lighter glueballs often forbidden because of q.-n.

– No mixing effects for oddballs

Glueballs (gg)

C. Morningstar, M. Peardon; Phys. Rev. D 60 (1999) 034509

Charmonium

4000

2000

0++2++ 1+– 2-+ 3++ 1++ 1-- 3--

0-+ 0+- 1-+ 2+- 2-- 0-- 3-+3+-

JPC

UKQCD Collaboration, G. S. Bali et al., Phys. Lett. B309 (1993) 378.

6000

[MeV]


Charmonium States and PredictedGlueballs


Physics Program / Heavier Glueballs

Production cross section:

Maybe high in pp-annihilation (see f0(1500))

Comparable to qq-systems (! µb)

Experimental program at HESR

p-scan for non-exotics: pp → (gg) → φφ, φη(Most reasonable channels, easily distinguishable,

low l - waves (simple PWA))

Production exp. for exotics: pp → (gg) + π

Reasonable measuring times


Physics Program / Measurements in the Charm Region

Spin non exotic states X pp X p scan− → −: ( )

Spin exotic states qq Y pp Y oduction e− → +(# ) : , ,... (Pr mod )π η

Heavier qq mesons n mK

Heavier Glueballs

Charmed Hybrids J

− → +→→

πφφ φη

ψη

,...

, ,...

/ ,...

X :

Y : Oddballs

Charmed Hybrids e g groundstates

→→

ηπ φφχ ππ

, ,...

( ) ,... ( . . )


Physics Program / Hadrons in Nuclear Matter1) Effective masses of hadrons in the nuclear medium – 206Pb(d, 3He), Q-Value

– K+, K–-Production in heavy ion collisions

Excitation spectra → (mK)Eff.


Physics Program / Hadrons in Nuclear MatterEffective D-masses in nuclear medium

– Dramatically increased DD-decay rate of ψ’- and χC2-states in nuclear medium

Substantial increase of widths (0.3 MeV → ?; 2.0 MeV → ?)

– Increased width of ψ(3770) (24 MeV → ?)


Physics Program / Hadrons in Nuclear Matter2) J/ψ - nucleon absorption cross section

Important for J/ψ - suppression in QGP

Proposed reaction: p(3.4-4.6 GeV/c) + A → J/ψ + (A-1)

Furthermore:

– cc - dissociation to open charm in the presence of nucleons:

– Elastic J/ψ - nucleon cross sections (Low momenta)

pd D c→ +− +Λ

pd J n→ + +/ψ γ


Physics Program / Double Hypernuclei3) Strange Baryons in Nuclear FieldHypernuclei = Third dimension of the nuclear chart

Production of Double Λ-Hypernuclei:

p GeV c A KK A A( . / ) ( ) ;(slow)

Trigger

(slow)2 6 + → + ⋅⋅⋅ + ′ → ′− −Ξ Ξ Ξ ΛΛ1 24 34

Active, secondary target


Physics Program / Further Options

– Baryon SpectroscopyNew states, Quantum numbers and decay rates

– Rare D-decaysExample:

– Direct CP-Violation in Λ, Λ-decays

Compare angular decay asymmetries

Prediction (SM) ≈ 2x10-5 HESR: 1 year of beamtime

D BR f+ + −→

⋅⋅ ⋅ ⋅

µ ν ψ( ~ ) ~ ~ ( )

Sensitive Test of LQCD,

10 0402 2Γ

( , ) for /α α π πΛ Λ→ →− +p p

A ≈ +−

α αα α



Direct CP-Violation (SCS)

D D r SM r r0 0 8 410 10/ Mixing ( ) ( ) HESR : / ~− < − −∆

Compare * / * Asymmetries ( )HESR /

D K K D K K A SMA A

+ + − − −

− −→ → <

= ≈ −0 0 3

4 310

10 10∆

CP-Violation in charmed region



Study of reversed Deeply Virtual Compton Scattering (DVCS) → Nucleon structure functions

Low energy p-physics

– pp-annihilation process

– Antiprotonic atoms

– Antihydrogen

p p+ → + → ++ −γ γ γ* l l


Status of the Project

May 1999Jan. 2001Nov. 2001

July 2002

Nov. 2002

Jan. 2003

: LOI for HESR (www.ep1.rub.de/gsi/part1.ps.gz): Start of Detector simulations (Geant 4): Conceptual Design Report (www.gsi.de/GSI-Future) Review by an International Committee of the „Deutsche Wissenschaftsrat“ : First Meeting of the PANDA collaboration (35 Institutions, 160 scientists so far): Very positive vote of the „Deutsche Wissenschaftsrat“ Start of R&D work for the PANDA detector: Promise for funding of the project by the German Ministery for Research and Technology


Conclusion– HESR will deliver cooled high quality antiproton beams with energies up to 15 GeV

– Antiproton induced reactions exhibit unique features

– High statistics data

– Low multiplicity events

– Symmetric production of particles and antiparticles

– High production rates for gluonic hadrons

– Many states can be directly formed

– Rich and unique Physics Program with emphasis on charmed particles

– Precision charmonium spectroscopy

– Search for charmed hybrids and heavier Glueballs

– J/ψ-Nucleon interactions

– Effective masses of hadrons in nuclear matter

– CP-violation in the charm sector

– Low energy p - physics, including Antihydrogen experiments

hadron physics with antiprotons - panda experiment · 2006. 1. 9. · h. koch, leap03, yokohama,...

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