e e physics from f to y

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L.N.F. 31/05/06
Prospects for ee- physics at LNF from f to y
INFN RoadMap Working Group F.Ambrosino,
F.Anulli, D.Babusci, S.Bianco, C.Bini, N.Brambilla
, R.DeSangro, P.Gauzzi, P.M.Gensini, S.Giovannella
, V.Muccifora, M.Negrini, F.Nguyen,
S.Pacetti, G.Pancheri, M.Passera, A.Passeri,
A.D.Polosa, M.Radici, Y.N.Srivastava, A.Vairo,
G.Venanzoni, G.Violini Cosenza,Ferrara,Frascati,M
ilano,Napoli,Padova,Pavia,Perugia,Roma1,Roma3 arX
ivhep-ex/0603056 LNF 06/11 (IR) http//www.roma
1.infn.it/people/bini/roadmap.html
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Outline
1. The physics case for DANAE (DAFNE-2)

• Physics at a high luminosity f factory
• (non K-decays and non hypernuclei)
• ee- physics in the energy range 1 lt vs lt 2.5 GeV

2. Detector considerations
3. An higher energy option the t charm factory
4. Final remarks
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1. The physics case for DANAE (DAFNE-2)

• Measurement of ee- ? hadrons cross-section in
  the range
• 2Mp lt vs lt 2.5 GeV.
• ? hadronic contributions to g-2
• ? hadronic contributions to aem running
• ? vector meson spectroscopy
• (2) Radiative decays of vector mesons
• ? h, h physics (from the f)
• ? physics of scalar mesons (multiquark states)
• (3) gg physics
• ? gg?p0p0, pp- from threshold up to 1GeV the
  s
• ? gg widths of scalar and pseudoscalar mesons
• (p0, h, h, f0(980), a0(980))
• (4) Hadron form-factors in the time-like region
• ? proton, neutron, L, S
• (5) Systematic of K N interactions

Mostly hadron physics precision tests of the SM
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Status of Rhad measurements

• ?s lt 1 GeV accessible through radiative return
  work in progress by KLOE
• 1 lt ?s lt 2.5 GeV accessible with energy scan.

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• ?s lt 1 GeV dominant for g-2.
• Best measurements
• KLOE (rad.ret.)
• CMD-2 / SND ee- energy scan.
• agreement between rad.ret. and ee- data ? dR/R
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• disagreement with t data (but the situation is in
  progress)

Comparison between t data (yellow band) KLOE
rad.ret. data (black) ee- scan data (colors)
am (g-2)/2 amexp-amth 2 ? 3 st.dev.
(ee-) 1 st.dev. (t)
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• 1 lt ?s lt 2.5 GeV dominant for aem.
• Old experiments with large systematic
  uncertainties
• B-factories (rad.ret.)
• Inclusive vs. Exclusive measurements

Impact of DANAE scan Statistical errors only
(same binning) ds(4p)/s(4p) () BABAR present
(blue) BABAR final (green) DANAE 1 year (red)
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• Summary Precision Tests of the Standard
  Model
• am (g-2)/2 (10-11)
• Present situation
• d(am)exp 60 ? 25 (BNL E969, ?)
• d(am)th (60?90)HLO based on dR/R 1
  (?slt1 GeV)
• ? (25?40)LBL purely theory
• Marginal improvement can be foreseen for g-2
• Dahad (10-5)
• Present situation d(Dahad ) 35 ?
  d(sin2qefflept)12.5
• dR/R 1 (?sltM(J/y)) ? d(Dahad ) 7 ?
  d(sin2qefflept)2.5
• Very important improvement for aem
• Energy scan is very important.

Competitors B-factories and t charm factories
(rad.ret.) VEPP-2000 _at_ Novosibirsk ?s lt 2 GeV L
lt 1032 cm-2s-1 from 2007
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An alternative measurement of running
aQED (thanks to L.Trentadue) through Small Angle
Bhabha extending the LEP analysis at lower q2.
t -1/2s(1-cosq)
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Energy scan ? Vector (and Scalar) Meson
Spectroscopy
Several new questions after Babar rad.ret.
data r w and f recurrencies how many, which
masses ? Do they fit quark model multi-plets ?
r(1900) baryonium ? hybrid meson ? ff0(980) vs
fh cross-sections evidence of 4-quark
f0(980) Structure ?
Observations of r(1900)
Competitors same as above (VEPP2000 limited to 2
GeV)
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Radiative decays a tool for low mass meson
physics
f decays source of ?Pseusoscalar Mesons
2 109 h and 107 h with 50 fb-1 h ?
p0gg h ? pp-ee- h ? pp-h h ? pp-g h ?
pp-p0 ? Scalar mesons pp, hp, KK f0(980),
a0(980) ? KK
Competitors ( on h , h ) WASA_at_COSY AND
CrystalBall_at_MAMI high flux hadronic machines
probably complementary to DANAE
Radiative decays of vector recurrencies to scalar
mesons e.g. G(r(1700) ? f0(1370)g)/
G(r(1700) ? f0(1500)g) useful for
understanding the second scalar multi-plet.
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gg physics study of 0 and 0- hadronic states
Lint 1 fb-1
?s 1 GeV low mass spectrum p, h, pp
threshold ?s 2.4 GeV extend to the region of
h, f0 and a0, hp and KK thresholds.
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Is a Small Angle Tagger needed ? Probably Yes, to
reduce the hadronic backgrounds (expecially at
the f energy) BUT it limits the accessible part
of the spectrum
Simulated pp spectra with and without tagging _at_
?s 1 GeV and 2.4 GeV
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gg ? p0p0 search for the s, the lowest
mass scalar meson. Fundamental ingredient to
assess the 4quark nature of the scalar
multi-plet.
Recent estimate of the s effect on ee- ? ee-
p0p0 cross-section (F.Nguyen, F.Piccinini and
A.D.Polosa hep-ph/0602205)
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Time-Like Form Factors of the Baryons Poor
experimental information in the t-l Neutron vs.
Proton, asymptotic behaviours,. Open problem in
the s-l (GE/GM)p vs q2 2g contribution
Polar angle distribution ? GE(s) and
GM(s) asymmetry in q ? 2g contribution (A ? 0)
Polarization of the outgoing nucleon ?
phase difference dE-dM even with unpolarized ee-
beams
From a complete measurement at ?s GE(s)
GM(s) dE-dM and A
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Sensitivity (model dependent) Numerical
simulation assuming 1 month data taking _at_
1032 cm-2s-1 ,20 bin 0.1 GeV2 large 1/s5
behaviour of the cross-section A 0.2 GE (?
6 effect to explain s-l discrepancy)
Angular distributions
Polarisation measurement vs. q
Competitors B-factories (rad.ret.) proton only,
in progress VEPP2000 _at_ Novosibirsk proton and
neutron up to 2 GeV PANDA/PAX _at_ GSI proton
only, but pol. gt2013
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Systematic of KN interactions using
monochromatic kaons from f decays ? K
interactions on gas (He, H2,..) ? KL
interactions on gas and targets
(including regeneration) Several millions of
events expected
Motivations (apart from hypernuclei) gKNL and
gKNS are unknown L(1405) assessment Radiative
captures
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2. Detector considerations

• For the DANAE program a general purpose detector
  is
• required with the following general features
• Full angular coverage
• Efficient tracking down to low momentum
  particles
• Hermetic calorimeter efficient down to low energy
  g
• Good particle identification.
• Some special features
• ? Small Angle Tagger for gg physics
• ? Polarimeter for proton and neutrons
• ? Neutron detector efficient for kinetic
  energies
• 3 lt Ekin lt 300 MeV.

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Assuming one interaction region only we have
studied the possibility of using KLOE as base
detector Open questions ? need of a vertex
detector (h ? pp-ee-, f ? KK-g,
multi-hadrons) ? need to improve calorimeter
granularity (h ? p0gg , a0, f0 ? 5g) ? Small
Angle Tagger vs. machine configuration ?
Neutron detection with the KLOE calorimeter (a
study is in progress on this point) ? How to do
the polarimeter ? ? Compatibility between
polarimeter and vertex detector.
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3. An higher energy option the t charm factory
ee- machine 3 lt ?s lt 3.8 GeV L 1034
cm-2s-1 (present machines 10) Lint 100 fb-1
/ year large potentialities in flavour
physics to be considered within the
super-flavour factory project
Competitors CLEO-C is running the goal is to
collect lt 10 fb-1 between J/y, y(3770) and
DsDs threshold by 2008 BEPC-II will start in
2007 goal L 1033 cm-2s-1 B-factories are
running many t and charm physics results
Super-B-factories discussions are open (see
DIF06)
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(1) Hidden Charm physics analysis of
charmonium Precise extraction of SM parameters
(aS, mC) Charmonium decays (e.g. J/y ? g
hc) Exotic Spectroscopy in the charmonium
decays Search for new physics (LFV, EDM,) (2)
Open Charm physics use ee- ? y(3770) ? DD With
100 fb-1 (1 year)? CP Violations and D
mixing Charm decays are important for
analyzing B-decays (3) t physics LFV t ? mg _at_
10-9 level hadronic decays g-2 precision
measurement of mass and couplings
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4. Final remarks

• There is a wide experimental program for DANAE
• complementary to Kaon physics.
• Motivations come from hadron physics and
• from precision tests of the Standard Model.
• General considerations
• The energy increase is a fundamental ingredient.
• Ultimate and complete measurements.
• KLOE with some upgrades can be well-suited for
• such a program.

The t charm factory has to be considered as an
important option in the frame-work of the
Super-Flavour Factory.