1. PROSPETTIVE DI FISICA A DANE FASE 2
Fabio Bossi, LNF
Padova
20/11/03

2. Integrated luminosity (pb-1)
KLOE Data taking:
Days of running
Integrated luminosity (pb-1)
Total  L dt ~ 400 pb1
2002
Particles’ collection:
2001
7108 K+ K pairs
2000
5108 KS KL pairs
2107 
2003 run started in October on FINUDA. Goal: deliver ~200 pb1, then switch back to KLOE for a long run to deliver 1 fb1 .

4. DAFNE: PERSPECTIVES FOR AN UPGRADE
Two option under consideration:
 “High energy” (up to  2.4 GeV c.m.)
 Minor modification to the machine
 Physics case: baryons form factors, high precision spectroscopy
 “High luminosity ” (~ 1034 cm-2s-1)
 Major modification to the machine and/or radically new ideas
 Physics case: CPT tests, K rare decays, quantum interferometry, hypernuclear physics

5. High Energy
DAFNE 2

6. NUCLEON FORM FACTORS IN THE TIME LIKE REGION
Differential x-section:
GE, GM complex numbers, need polarization of final state to measure the relative phase needed to obtain FPauli and FDirac (i.e. what theorists calculate!)
GE = GM only at threshold, need to know angular distribution
At large Q2, G(Q2) = G(-Q2)
If only valence quarks GM(n) = GM(p) / 2

7. PROTON FORM FACTOR pQCD fit G(Q2) = G(-Q2)
factor 2 from naive prediction!
rapid fall just above threshold
A. De Falco

8. Ldt = 0.4 pb-1 NEUTRON FORM FACTOR Data from FENICE only, 74 events
GM(p)/2
GM(n) > GM(p) !
A. De Falco

9.  FORM FACTOR
Only one existing measurement (DM2) based on GeV

10. EVENT YIELDS
(e+e  NN) ~ 0.1  1 nb
400  4000 present luminosity
(e+e  ) ~ 0.1 nb
400 present luminosity
FINUDA estimates efficiencies ranging between (5  40)% for nucleons (no idea for ‘s)
Major limitation of FINUDA present setup is limited angular acceptance (KLOE has full solid angle coverage)
FINUDA might measure p polarization!

11. MY CONCLUSIONS ON BARYON F.F.
NUCLEON F.F. CAN BE MEASURED WITH UNPRECEDENTED PRECISION AT D2 AS LONG AS L > 1031
DISCRIMINATION BETWEEN nn AND  EVENTS (B/S ~ 4) BASED ON TIMING MIGHT RESULT VERY DIFFICULT DUE TO HIGH BUNCH X-ING RATE IN DANE
SOME R&D WORK HAS TO BE ENCOURAGED ON NEUTRON EFFICIENCY WITH PRESENT DETECTORS
LAMBDA F.F. MEASUREMENT SHOULD BE PURSUED  S > 2.4 GeV

12. Muon - Anomaly Anomalous magnetic moment of the muon am = (g-2)m
Motivation: Determination of Hadronic Vacuum Polarization = High Precision Test of the Standard Model:
Anomalous magnetic moment of the muon am = (g-2)m
Running Fine Structure Constant at Z0-mass aQED (MZ)
Hadronic Vacuum Polarization
2nd largest contrib., cannot be calculated in pQCD
Error of hadronic contribution is dominating total Error !
Dirac-Theory: (g - 2 ) = 0
Quantum Corrections: (g - 2 )  0 due to corrections of:
- electromagnetic Interaction
- weak Interaction
- strong Interaction (and maybe NEW PHYSICS ???)

13. } } Status: Muon - Anomaly How to test the Standard Model?
Compare experimental Value with Theory - Prediction for Muon-Anomaly
New Data Input from:
a) CMD-2 (Novosibirsk) in p+ p-
Channel: 0.6% Precision < 1 GeV
reanalysis of their data publ. ’08/03
b) t-Data from ALEPH, OPAL, CLEO
Experiment E821 (BNL ‘02)
dam(exp.) = ± 0.7 ppm
THEORY: ’
THEORY ’03 }
Theory Evaluation using only
e+ e- - Data 2 s - Deviation }
Theory Evaluation using only
t – Data: Agreement with Exp.
PRESENT KLOE DATA CONFIRM CMD-2

14. A. Denig

15. A. Denig (Alghero Workshop)

16. WHAT CAN BE USED FROM DAFNE
DAFNE2 can exploit DAFNE hardware:
vacuum chamber
all quads and sexts
RF cavity
Feedback, vacuum system...
But needs new:
stronger bending dipoles
4 SC quads in IR2
C. Biscari

18. Dipole Section

19. Magnetisation curve
1100 MeV
1050 MeV
1020 MeV
510 MeV

20. Injection - Full Energy
Linac upgrade up to 1.1 GeV
injecting directly in rings
+ transfer lines + septa
DOUBLING THE DAFNE-LINAC ENERGY IS FEASIBLE AT MODERATE COST (~6 MEuros)
C. Biscari

21. or Injection - Ramping
… there is no problem implementing energy ramping for DAFNE II
Inject and ramp time << beam lifetime at 1.1GeV
All of the PS can be reused
It simply requires:
High Level Software development
careful hardware configuration.
C. Biscari

22. Conclusions of High E option
Energy upgrade to 1.02 GeV/beam straightforward
and at moderate cost
Exploit most of existing hardware
Preliminary design for dipoles
with some questions about
- maximum achievable field (-> Emax ~1.1 GeV)
- current dependence of field quality
Parameters of superconducting IR quadrupoles
are well within the range of existing designs
C. Biscari

23. High Luminosity
DANE x 100

24. Ideas for Luminosity increase
Some will be tested
in near future:
Others …
collisions with neutralized beams
(four beams) + feedback system
ring against linac
Monochromators
Collisions with large crossing angle:
Ecm= 2Ebeamcos(qc/2),
e.g. qc/2 =60°,Ebeam=1GeV
Crab cavities (KEK-B)
Collisions with round beams (VEPP2000)
Negative aC (KEK-B, DAFNE)
C. Biscari

25. A novel approach: large crossing angle
If we want to collide at the F-pole, we could increase the ring Energy by greatly increasing the crossing angle 2a, such as:
Ecm= 2Ebeamcos(a)
detector
Ecm = 1 GeV KS KL
E + 1 GeV F F F
E - 1 GeV
For example a=60°
corresponds to Ebeam=1GeV

26. + Main guidelines for the design L ~ 10 34 at F energy Double ring
Multibunch operation +
Powerful damping
Negative momentum compaction
Very short bunch at IP
C. Biscari

27. Luminosity 1034 set of consistent parameters
new
challenges
C. Biscari

28. ZOOM OF THE
RINGS SECTION
QUADRUPOLES
SEXTUPOLES 1m

29. Charge asymmetry in KS semileptonic
KLOE AT DANE
Nature of scalar mesons
KS semileptonic decay
KS decay into 2
Yesterday (20 pb-1)
More a), b), c)
Charge asymmetry in KS semileptonic
Main and medium-rare decays of KL and K
Vus measurement
Hadronic cross section
Limits on KS  3
Today (400 pb-1)
More 2), 6) and part of 3)
Quantum interferometry …
Tomorrow (2000 pb-1)

30. DANE
The  decay at rest provides monochromatic and pure beams of Kaons
K rare decays
Absolute branching ratios
K lifetimes
K+K- 1.5 106 /pb-1 p = 120 MeV/c
KLKS /pb p = 110 MeV/c
The variety of K decay channels and the possibility for a complete closure of the kinematics allow the selection of many samples for measuring the efficiencies directly from data.
The  decays at rest allow us to select monochromatic (p ~ 110 MeV/c) pure beams of Kaons:
K rare decays.
Absolute branching ratios:
K life times:
The variety of K decay channels and the possibility for a complete closure of the kinematics allow the selection of many samples for measuring the efficiencies directly from data.

31. Tagged KL and KS “beams”
KL tagged by KS  p+p- at IP
Efficiency ~ 70% (mainly geometrical)
KL angular resolution: ~ 1°
KL momentum resolution: ~ 2 MeV
KS  p+p-
KL  2p0
KS tagged by KL interac. in EmC
Efficiency ~ 30% (largely geometrical)
KS angular resol.: ~ 1° (0.3 in f)
KS momentum resolution: ~ 2 MeV
KL “crash”
= 0.22 (TOF)
KS  p-e+n

32. KL: B/B ~ 0.7% AL ~ 0.007 % B/B ~ 1.6% AS ~ 1.3 % 170 pb-1
KS SEMILEPTONIC DECAYS
170 pb-1
BR(KS  e) = (6.8 0.15) 10-4
ASL = (19 18) 10-3
KL:
B/B ~ 0.7%
AL ~ %
Preliminary result using all data to be presented at next SC
B/B ~ 1.6%
AS ~ 1.3 %

33. <e+ | Hwk | K0 > <e+ | Hwk | K0 > S L 8 103 =
KS SEMILEPTONIC DECAYS AND THE S = Q RULE
The relevant parameter is:
<e+ | Hwk | K0 >
Re (x+) ~
~ 106 S.M.
<e+ | Hwk | K0 > S
1 + 4 Re(x+) = =
Present Uncertainties L
8 103
BR(KS  e) L =
BR(KL  e) S
1 103
7 103
KLOE can improve a lot on this with present data
10 fb1 would give ~ 2 103 on BR(KS )

34. Suppressed by DS=DQ rule (c=d=0) p-e+nHWK0 = a + b
KS SEMILEPTONIC DECAYS AND TESTS OF CPT
In the SM:
b=d=0 if CPT holds
Suppressed by DS=DQ rule (c=d=0)
p-e+nHWK0 = a + b
p+e-nHWK0 = a*- b*
p+e-nHWK0 = c + d
p-e+nHWK0 = c*- d*
AS = 2(Re eK + Re dK + Re b/a - Re d*/a)
AL = 2(Re eK - Re dK + Re b/a + Re d*/a)
4 Re  ~ AS - AL CP
CPT
Test if AS consistent with 2 Re 
2 fb-1
Next run
Measurement of AS to 30%
20 fb-1
DANE 2
100 fb-1
Competitive measurement of Re 

35. One can improve e/ separation increasing calorimeter granularity
The numbers above assume present detection efficiency for signal TOT ~ 6%
One can recover some acceptance by the use of a vertex detector and a lower magnetic field
One can improve e/ separation increasing calorimeter granularity
R&D work needed !

36. efficiency after all fiducial cuts ~ 10%
KS  30
This CP violating decay has a predicted B.R. of 9 with a relative error of 2.4%
KLOE will present at next SC its preliminary limit with present statistics (O(107) )
efficiency after all fiducial cuts ~ 10%
NOBS ~ 20 events in 100 fb1
At this level some more work on background rejection needed!

37. Kaon interferometry: what can be measured
A . Di Domenico
Double differential time distribution:
where t1(t2) is the time of one (the other) kaon
decay into f1 (f2) final state and:
characteristic interference term
at a f-factory => interferometry
fi = p+p-, p0p0, pln, p+p-p0, 3p0, p+p-g ..etc
Integrating in (t1+t2) we get the time difference (Dt=t1-t2) distribution (1-dim plot):
From these distributions for various final states fi we can measure the following quantities:

38. Kaon interferometry: main observables
A . Di Domenico
mode
measured quantity
parameters

39. At a new f-factory with 100 fb-1 : dDm ~ 0.018  10-11  s-1
KLOE preliminary
340 pb1
Dm = (5.64  0.37)  1011  s-1
PDG ’02: (5.301  0.016)  1011  s-1
FIRST EXAMPLE OF QUANTUM INTERFERENCE WITH KAONS
At a new f-factory with 100 fb-1 :
dDm ~   s-1

40. KLOE has just started attacking its main original program i. e
KLOE has just started attacking its main original program i.e. measuring all the parameters of the neutral K system ( among which Re (‘/) ), for which it were originally estimated to be needed 510 fb1
With present efficiencies one may think to need 2050 fb1 i.e. DANE 2
Again, KLOE experience (phase 1) can be a guidance to possible hardware interventions on the detector to improve its performace (better QCAL?, vertex detector?)

41. G(KL  gg) / G(KL  p0p0p0) R=(2.79±0.02stat±0.02syst)10-3
AN INTERLUDE : KL  2
G(KL  gg) / G(KL  p0p0p0)
NA48 e KLOE have measured R =
R=(2.79±0.02stat±0.02syst)10-3
(370 pb1 )
KLOE
R=(2.81±0.01stat±0.02syst)10-3
NA48
The value of BR(KL  2) is presently limited by BR(KL  p0p0p0 ) that is know to ~ 1.3%
KLOE will measure this BR to << 1% with present data
A new measurement of R to a better precision (both statistical and systematical) will soon be needed

42. = Theoretical error < 10%
G. Isidori
= Theoretical error < 10%

43. KL 0 at a  factory?
Kaons are tagged
Kaons 4-momentum is known (reconstruction of decay kinematics allowed)
Beam free of neutral baryons backg.
A -factory is naturally suited for this search since:
Production rate: 106 KS-KL pairs / pb-1
cm-2s-1 : 1012 KL produced
observed decays: 30  tot / year (SM)
must be tot  10%

44. …but still remember
G. Isidori, Alghero Workshop

45. HYPERNUCLEAR SPECTROSCOPY

46. OPEN QUESTIONS
A. Feliciello

47. FINUDA IS COMING!
A. Feliciello

48. ONE STEP BEYOND:  SPECTROSCOPY
NEED HIGH LUMINOSITY DUE TO LOW EVENT RATES (AND LOW DETECTOR EFFICIENCIES)
A. Feliciello

49. SLIGHTLY REDUCED DETECTOR ACCEPTANCE
FINUDA WITH GERMANIUM DETECTOR
SLIGHTLY REDUCED DETECTOR ACCEPTANCE
A. Feliciello

50. PRODUCTION OF NEUTRON RICH HYPERNUCLEI
V. Paticchio
Typical counting rate with : 130 ev/h

51. DAFNE status and outlook
Adiabatic changes on DAFNE approaching to an end.
DAFNE performances expected to reach the original design goals (L= 5 * 10 32), within the next 2 years.
3- 4 years of physics program fully booked with current (or slightly upgraded) detectors.
After that, only radical changes possible
S. Bertolucci, closing Alghero workshop