Paola Gianotti - LNF Goals and achievements in meson spectroscopy: LEAR and FermiLab activities Overview of the GSI Future Project The Antiproton

Paola Gianotti - LNF

Goals and achievements in meson spectroscopy:LEAR and FermiLab activities

Overview of the GSI Future Project The Antiproton Physics Program

Charmonium spectroscopyHybrids and glueballsMedium modification of mesonsHypernuclei

The PANDA detector concept Conclusions

From LEAR to HESR:From LEAR to HESR:

past, present and future of mesonpast, present and future of meson

spectroscopy with antiprotons spectroscopy with antiprotons


Goals and achievements in meson spectroscopyGoals and achievements in meson spectroscopy

QCD is the accepted theory of strong interaction even if calculating the properties of mesons from the QCD Lagrangian is very difficult phenomenological models are used instead

All these models predict in addition to

conventional states exotic states with

explicit glue content

Some of these exotic states have been finaly identified even if our understanding of ordinary mesons is not exhaustive


Different experimental techniques are used to disentangle these states:

• Studies of different final states;

• Selection of special working conditions or final states to filter

initial state quantum numbers;

• Production mechanisms ( collisions, pp annihilation,

peripheral or central production, etc).

Goals and achievements in meson spectroscopyGoals and achievements in meson spectroscopy

Meson spectrum consists of an increasingly large number of broad overlapping states crowed in the mass region around 1÷2 GeV.


The LEAR The LEAR inheritanceinheritance

Three glueball candidates: f0(1500), f0(1370), f0(1710) 0++

(1440) 0+

Two hybrids candidates: 1(1400), 1(1600) 1+

Beam intensity 104 ÷ 106 p/s

Beam momentum

100÷2000 MeV/c

Δp/p 10-3

Machine vacuum 10-11÷ 10-12 Torr

circumference 78.54 m


OBELIXOBELIX

A.Bertin et al.,Physics Letters B385, (1996), 493. A.Bertin et al.,Physics Letters B400, (1997), 226.

A.Bertin et al.,Physics Letters B361, (1995), 187.

F.Nichitiu et al.,Physics Letters B545, (2002), 261.

The LEAR inheritanceThe LEAR inheritance

Crystal BarrelCrystal Barrel


The Fermilab activityThe Fermilab activity

0

Many results come from E760-E835 experiments at Fermilab Antiproton Accumulator

8·1011 p per stackaccumulation rate 4 · 1010 p/hp accumulated at 8.9 GeV/c anddecelerated decreasing dipole current “fine scan” using stochastic cooling

Initial beam intensity 1012 p Gas jet target density 1012 ÷1014 atoms/cm3

to keep luminosity constant 2·1031 cm-2sec-1

Momentum spread p/p 10-4→ (√s) 200 KeV

8·1011 p per stackaccumulation rate 4 · 1010 p/hp accumulated at 8.9 GeV/c anddecelerated decreasing dipole current “fine scan” using stochastic cooling

Initial beam intensity 1012 p Gas jet target density 1012 ÷1014 atoms/cm3

to keep luminosity constant 2·1031 cm-2sec-1

Momentum spread p/p 10-4→ (√s) 200 KeV


SIS 100/300

HESR

SuperFRS

NESR

CR

p Target

GSI Future FacilityGSI Future Facility

UNILAC SIS

FRS

ESR

Primary Beams

• 238U28+ 1.5 GeV/u; 1012/s ions/pulse • 30 GeV protons; 2.5x1013/s

• 238U73+ up to 25 (- 35) GeV/u; 1010/s

Storage and Cooler Rings

• Radioactive beams• e – A collider

• 1011 stored and cooled p0.8 - 14.5 GeV

• Cooled beams• Rapidly cycling superconducting magnets

Key Technical Features

• Broad range of radioactive beams up to 1.5 - 2 GeV/u• Antiprotons 3 (0) - 30 GeV

Secondary Beams• From protons to uranium- In future also atiprotons

• From 1MeV/u to 2 GeV/u- In future up to 30 GeV/u

• 109 to 1011 particles/cycle - In future 1012 particles/cycle• 0.1Hz to 1Hz repetition rate

- In future up to 3 Hz

• From protons to uranium- In future also atiprotons

• From 1MeV/u to 2 GeV/u- In future up to 30 GeV/u

• 109 to 1011 particles/cycle - In future 1012 particles/cycle• 0.1Hz to 1Hz repetition rate

- In future up to 3 Hz


HESR - High Energy Storage RingHESR - High Energy Storage Ring

High luminosity mode High resolution mode

• p/p ~ 10-5 (electron cooling)• Lumin. = 1031 cm-2 s-1

• Lumin. = 2 x 1032 cm-2 s-1 • p/p ~ 10-4 (stochastic cooling)

• Production rate 2x107/sec

• Pbeam = 1 - 15 GeV/c

• Nstored = 5x1010 p

• Internal Target


Charmonium spectroscopyCharmonium spectroscopy

Charmonium spectrumis becoming more clear…

• 5 new measurements of c mass


Even on the ground state on the simplest parameters thereare consistency problems…

Five new measurements published 2002-2003,four by e+e- experiments



Charmonium spectrumis becaming more clear…

• ’c unambiguously seen




3580 3600 3620 3640 3660 3680

CBALL 86(2S)→X

’c

3637.7±4.4 MeV

BELLE 02B→K (KSK+-)

BELLE 03e+e-→J/ X

CLEO 03→KSK+-

BABAR 03→KSK+-

Mass (MeV)

New measurementsof mass are consistent!

tot = (19 ± 10) MeV



Charmonium spectrumis becaming more clear…

Open problems…


• ’c unambiguously seen

• h1c not confirmed

•States above DDthr. are not well established



MassDecay

channelsstudied

Total BR seen (%)Decay

ChannelsWith error <30%

c 2979.6±1.2 21 60.3 3

’c 3654.0±6.0 4 ~ 0 0

J/ 3096.92±.01 135 44.2 83

’ 3686.09±.03 62 77.1 29

c0 3415.2±0.3 17 12.3 10

c1 3510.59±.10 13 33.6 6

c2 3556.26±.11 19 26.3 10

hc 2 ? 0

(3770) 3770.0±2.4 2 ~ 0 1

(3836) 3836±13 1 ~ 0 0

X(3872) 3872.0±0.6 3 ~ 0 0

(4040) 4040±10 6 ~ 0 1

(4160) 4159±20 1 ~ 0 0

(4415) 4415±6 2 ~ 0 0


3500 3520 MeV3510C

Ball

ev./

2 M

eV

100

ECM

CBallE835

1000

E 8

35

ev./

pb

c1

Charmonium PhysicsCharmonium Physics

e+e- → ’→

→ e+e-→ J/

● e+e- interactions:

- Only 1-- states are formed- Other states only by secondary decays (moderate mass resolution)

- All states directly formed (very good mass resolution)

→ J/→ e+e-

p p→ 1,2

● pp reactions:

Br(e+e- → ) ·Br( → c) = 2.5 10-5Br(pp → c) = 1.2 10-3


Exotic hadronsExotic hadrons

In the light meson spectrum exotic statesoverlap with conventional states

The QCD spectrum is much rich than that of the naive quark model also the gluons can act as hadron components

The “exotic hadrons” fall in 3 general categories:

(qq) gHybrids

Glueballs

(qq)(qq)Multiquarks

Exoti

c lig

ht

qq

Exoti

c cc

1 -- 1-+

0 2000 4000MeV/c2

10-2

1

102

Paola Gianotti - LNFE

xoti

c lig

ht

qq

Exoti

c cc

1 -- 1-+

0 2000 4000MeV/c2

10-2

1

102


The QCD spectrum is much rich than that of the naive quark model also the gluons can act as hadron components

The “exotic hadrons” fall in 3 general categories:

(qq) gHybrids

Glueballs

(qq)(qq)Multiquarks

In the cc meson spectrum the density of states is lower and therefore the overlap


In the light meson region, about 10 states have been classified as “Exotics”. Almost all of them have been seen in pp...


Main non-qq candidates

f0(980) 4q state

f0(1500) 0++ glueball candidate



(1410); (1460) 0+ glueball candidate

f1(1420) hybrid, 4q state

1(1400) hybrid candidate 1


(1800) hibrid candidate 0



a2’(2100) hybrid candidate 1++


Production

all JPC available

Formation

only selected JPC

Exotic mesons are produced with rates similar to qq conventional systems

All ordinary quantum numbers can be reached ~1 b

All ordinary quantum numbers can be reached ~1 b

p

p_

G

p

p_

H

p

p_

H

Glueballs and HybridsGlueballs and Hybrids

p

p_

G

M

p

M

H

p_

p

M

H

p_

Even exotic quantum numbers can be reached ~100 pb

Even exotic quantum numbers can be reached ~100 pb


p

p_

G

M

p

M

H

p_

p

M

H

p_production

p

p_

G

p

p_

H

p

p_

Hformation


● Gluonic excitations of the quark-antiquark-potential

may lead to bound states

● LQCD: mH ~ 4.2-4.5 GeV ; JPC 1-+

Charmed HybridsCharmed Hybrids

● Flux tube-Model predicts HDD** (+c.c.) decaysIf mH<4290 MeV/c2→

H < 50 MeV/c2

● Some exotics can decay neither to DD nor to DD*+c.c.– e.g.: JPC(H)=0+-

• Flux-tube allowedc0,c0,c2,c2,

c,h1, h1c• Flux-tube forbidden

J/f2,J/()S

– Small number of final states with small phase space

r0=0.5fm

BaBar and Belle would expect ~300 evts. each in 5 years not competitive


• Light gg/ggg-systems are complicated to be identified

• Oddballs: exotic heavy glueballs– m(0+-) = 4740(50)(200) MeV– m(2+-) = 4340(70)(230) MeV

• Width unknown, but!– nature invests more likely in

mass than in momentum good prob. to see in charm channels

– Same run period as hybridsMorningstar and Peardon, PRD60 (1999) 034509Morningstar and Peardon, PRD56 (1997) 4043

GlueballsGlueballs


Mesons in nuclear matterMesons in nuclear matter

One of the fundamental question of QCD is the generation of

MASSThe light meson masses are larger than the sum of the constituent quark masses!

Spontaneous chiral symmetry breaking seems to play a decisive role in the mass generation of light mesons.

How can we check this?



Since density increasein nuclear matter is possible a partial restoration of chiral symmetry

● Light quarks are sensitive to quark condensate

Evidence for mass changes of pions and kaons has been observed

● Deeply bound pionic atoms

Nucleus-Nucleus CollisionsProton-Proton Collisions

K-

K+

K-

K+

f* = 0.78f

● Kaon-production environments


pionic atoms

KAOS/FOPI

HESR

π

K

D

vacuum nuclear mediumρ = ρ0

π+

π-

K-

K+

D+

D-

25 MeV

100 MeV

50 MeV

Mass modifications of mesons

With p beam up to 15GeV/c these studieswill be extended

Sub-threshold enhancement for D and Dmeson productionexpected signal:

strong enhancement of the D-meson cross section, relative D+ D- yields, in the near/sub-threshold region.


pp→ D+D-

10-2

10-1

1

10

102

103

(nb)

4 5 6 7

D+

D-

T (GeV)

in-medium

free masses



The lowering of the DD thresh.

– allow ’,c2 charmonium states

to decay into this channel

3

GeV/c2 Mass

3.2

3.4

3.6

3.8

4

(13D1)

(13S1)

c(11S0)

(33S1)

c1(13P1)c1(13P0)

DD3,743,64

3,54

vacuum10

20

thus resulting in a substantial increase of width of these states

c2(13P2)

(23S1)

– states above DD thresh. would have larger width

Idea– Study relative changes of yield and width of the charmonium

state (3770).

BR into (10-5 in free space)

Predictions by Ye.S. Golubeva et al., Eur.Phys.J. A 17,(2003)275


J/J/ Absorption in Nuclei Absorption in Nucleie-

e+

J/

p● Important for the understanding of heavy ion collisions related to QGP

● Reaction

p + A → J/ + (A-1)

→e+e

● A complete set of measurements could be done - J/, ‘, J on different nuclear target

- Longitudinal and transverse Fermi-

distribution is measurable


s

ud

s

dd

s

ds

s

ss

0

• Use pp interaction to produce a hyperon “beam” (t~10-10 s) which is tagged by the antihyperon or its decay products

Hypernuclear PhysicsHypernuclear Physics

_

(Kaidalov & Volkovitsky)

quark-gluon string model


- capture:

- p + 28 MeV-

3 GeV/c

Kaons _

trigger

p_

2. Slowing down and capture

of insecondary

target nucleus

2. Slowing down and capture

of insecondary

target nucleus

1.Hyperon-

antihyperonproduction

at threshold

1.Hyperon-

antihyperonproduction

at threshold+28MeV

3. -spectroscopy

with Ge-detectors

3. -spectroscopy

with Ge-detectors

Production of Double HypernucleiProduction of Double Hypernuclei

-(dss) p(uud) (uds) (uds)


Expected Counting RateExpected Counting Rate

Ingredients (golden events)─ luminosity 2·1032 cm-2s-1 ─ +- cross section 2mb for pp 700 Hz─ p (100-500 MeV/c) p500 0.0005– + reconstruction probability 0.5– stopping and capture probability pCAP 0.20– total captured - 3000 / day

– - to -nucleus conversion probability p 0.05– total hypernucleus production 4500 /month

– gamma emission/event, p 0.5– -ray peak efficiency pGE 0.1

• ~7/day „golden“ -ray events (+ trigger)• ~700/day with KK trigger

high resolution -spectroscopy of double hypernuclei will be feasible


Other physics topicsOther physics topics

Cross section σ ≈ 2.5pb @ s ≈10 GeV2

L = 2·1032 cm-2 s-1→ 103 events per month

• Reversed Deeply Virtual Compton Scattering

• CP-violation (D/ – sector)- D0D0 mixing

SM prediction < 10-8

- compare angular decay asymmetries for

SM prediction ~ 2·10-5

• Rare D-decays:D+→+ (BR 10-4)

W+

c

d


Detector requests:

• nearly 4 solid angle (partial wave analysis)• high rate capability (2·107 annihilations/s)• good PID (, e, , , K, p)• momentum resolution (~1%)• vertex info for D, K0

S, (c = 317 m for D±)• efficient trigger (e, , K, D, )• modular design (Hypernuclei experiments)

General Purpose DetectorDetector


Detector Detector (top view)(top view)

target spectrometer forward spectrometer

micro vertexdetector

electromagneticcalorimeter

DIRC:Detecting InternallyReflectedCherenkov light

straw tubetracker

mini driftchambers

muon counter

Solenoidalmagnet

iron yoke


PANDA DetectorPANDA Detector


PANDA CollaborationPANDA Collaboration

•At present a group of 300 physicists

from 49 institutions of 11 countries

Basel, Beijing, Bochum, Bonn, Catania, Cracow, Dresden, Edinburg, Erlangen, Ferrara,

Franhfurt, Genova, Giessen, Glasgow, KVI Groningen, GSI, FZ Jülich I + II, JINR, Katowice,

Lanzhou, LNF, Los Alamos, Mainz, Milano, Milano Politecnico, Minsk, TU München,

Münster, Northwestern, BINP Novosibirsk, Pavia, Silesia, Stockolm, Torino I + II, Torino

Politecnico,Trieste, TSL Uppsala, Tübingen, Uppsala, SINS Warsaw, AAS Wien

Basel, Beijing, Bochum, Bonn, Catania, Cracow, Dresden, Edinburg, Erlangen, Ferrara,

Franhfurt, Genova, Giessen, Glasgow, KVI Groningen, GSI, FZ Jülich I + II, JINR, Katowice,

Lanzhou, LNF, Los Alamos, Mainz, Milano, Milano Politecnico, Minsk, TU München,

Münster, Northwestern, BINP Novosibirsk, Pavia, Silesia, Stockolm, Torino I + II, Torino

Politecnico,Trieste, TSL Uppsala, Tübingen, Uppsala, SINS Warsaw, AAS Wien

http://www.gsi.de/hesr/panda

Spokesperson: Ulrich Wiedner – Uppsala deputy

Austria – China - Germany – Italy – Netherlands – Poland – Russia – Sweden – Switzerland - U.K. – U.S.


ConclusionsConclusions

perform high resolution spectroscopy with p-beam in formation experiments:

E ≈ Ebeam

produce, with high yields, gluonic excitations: glueballs, hybrids, multi-quark states

≈ 100 pb

study partial chiral symmetry restoration by implanting mesons inside the nuclear medium

produce hyperon-antihyperon taggable beams

Thanks to the new GSI HESR facilityp will be used to...


Topic Competitor

ConfinementCharmonium

all cc states with high resolution

CLEO-C only 1–– statesformed

Gluonic Excitations

charmed hybridsheavy glueballs

CLEO-C light glueballsHall-D light hybrids

Nuclear Interactions

D-mass shift

J/ absorption (T~0)Dane K-mass shift

Hypernuclei-spectroscopy of- and -hypernuclei

JHF single HN

Dane high luminosity

Open Charm Physics

Rare D-DecaysCP-physics in Hadrons

CLEO-C rare D-DecaysCP-physics in D-Mesons

Competition Competition BES, CLEO, DaBES, CLEO, Dane, HallD, JHFne, HallD, JHF


Final state Cross section # rec. events

Meson resonance + anything

100mb 1010

50mb 1010

2mb 108

DD 250nb 107

J/(→e+e,) 630nb 109

2(→ J/) 3.7nb 107

cc 20nb 107

cc 0.1nb 105

HESR/ expected counting ratesHESR/ expected counting rates

One year of data taking ≈ 1-2(fb)-1

Documents

Paola Gianotti - LNF Goals and achievements in meson spectroscopy: LEAR and FermiLab activities Overview of the GSI Future Project The Antiproton