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PROSPETTIVE DI FISICA A DA  NE FASE 2

PROSPETTIVE DI FISICA A DA  NE FASE 2. Fabio Bossi, LNF Padova 20/11/03. Integrated luminosity (pb - 1 ). Days of running. KLOE Data taking: 2000-2002. Total  L dt ~ 400 pb 1. 2002. Particles’ collection :. 2001. 7  10 8 K + K  pairs. 2000. 5 10 8 K S K L pairs.

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PROSPETTIVE DI FISICA A DA  NE FASE 2

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

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

  3. 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

  4. High Energy DAFNE 2

  5. NUCLEON FORM FACTORS IN THE TIME LIKE REGION Differential x-section: GE, GMcomplex numbers, need polarization of final state to measure the relative phaseneeded 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 quarksGM(n) = GM(p) / 2

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

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

  8.  FORM FACTOR Only one existing measurement (DM2) based on 4 events @ 2.4 GeV

  9. EVENT YIELDS (e+e NN) ~ 0.1 1 nb 400 4000 events/day @ present luminosity (e+e ) ~ 0.1 nb 400 events/day @ 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!

  10. MY CONCLUSIONS ON BARYON F.F. NUCLEON F.F. CAN BE MEASURED WITH UNPRECEDENTED PRECISION AT D2 AS LONG ASL > 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

  11. HadronicVacuum Polarization 2nd largest contrib., cannot be calculated in pQCD Error of hadronic contribution is dominating total Error ! Muon - Anomaly • 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) Dirac-Theory: (g - 2 ) = 0 Quantum Corrections: (g - 2 )  0due to corrections of: - electromagnetic Interaction - weak Interaction - strong Interaction (and maybe NEW PHYSICS ???)

  12. Status: Muon - Anomaly How to test the Standard Model? Compareexperimental ValuewithTheory - Predictionfor Muon-Anomaly New Data Input from: a) CMD-2 (Novosibirsk) inp+ 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: ’08 2003 } THEORY ’03 Theory Evaluation using only e+ e- - Data 2s - Deviation } Theory Evaluation using only t – Data: Agreement with Exp. PRESENT KLOE DATA CONFIRM CMD-2

  13. A. Denig

  14. A. Denig (Alghero Workshop)

  15. 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

  16. Dipole Section

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

  18. 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

  19. 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

  20. 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

  21. High Luminosity DANE x 100

  22. 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

  23. F F F KL KS 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 E + 1 GeV E - 1 GeV For example a=60° corresponds to Ebeam=1GeV

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

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

  26. ZOOM OF THE RINGS SECTION QUADRUPOLES SEXTUPOLES 1m

  27. 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)

  28. Kaons @ 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 KLKS106/pb-1 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.

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

  30. 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 ~ 0.007 % Preliminary result using all data to be presented at next SC B/B ~ 1.6% AS ~ 1.3 %

  31. KS SEMILEPTONIC DECAYS AND THE S = Q RULE The relevant parameter is: <e+ | Hwk | K0 > ~ 106 S.M. Re (x+) ~ <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 )

  32. 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* KS SEMILEPTONIC DECAYS AND TESTS OF CPT In theSM: b=d=0 if CPTholds Suppressed by DS=DQ rule (c=d=0) AS= 2(ReeK + RedK + 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 

  33. 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 !

  34. KS 30 This CP violating decay has a predicted B.R. of 1.9 10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!

  35. 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:

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

  37. 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 newf-factorywith 100 fb-1 : dDm ~ 0.018  10-11 s-1

  38. 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50fb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?)

  39. 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

  40. G. Isidori = Theoretical error < 10%

  41. 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 1 year @ 1035 cm-2s-1 : 1012 KL produced observed decays: 30  tot / year (SM) must betot  10%

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

  43. HYPERNUCLEAR SPECTROSCOPY

  44. OPEN QUESTIONS A. Feliciello

  45. FINUDA IS COMING! A. Feliciello

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

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

  48. PRODUCTION OF NEUTRON RICH HYPERNUCLEI V. Paticchio Typical counting rate with FINUDA @ 1034 : 130 ev/h

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