KLOE CSN1. Catania, 16 September 2002

Transcription

1 KLOE CSN1 Paolo Franzini Università di Roma, La Sapienza Catania, 16 September 2002

2 OUTLINE 1. Brief htory 2. L and backgrounds 3. Computing 4. Physics Milestones th Catania, 16 September 2002 Paolo Franzini - KLOE , CSN1 2

3 1. Htory KLOE year anniversary. 1. KLOE design and msion 2. KLOE cost 3. Today th Catania, 16 September 2002 Paolo Franzini - KLOE , CSN1 3

4 Design And Msion Measure R(ɛ /ɛ) + much other physics K L π 0 π 0 for a stattical error of 10 4 Guess: need 1 year at L=10 33 cm 2 s 1 Including systematics a la NA K L π 0 π 0 So far got 2 20,000 K L π 0 π pb 1 Resolution as expected: good for t, OKforE, r, φ Can take the very high machine background, 100 because of the very flexible KLOE trigger but with efficiency losses th Catania, 16 September 2002 Paolo Franzini - KLOE , CSN1 4

5 Cost April 1, 1992 estimate: G. KLOE functional by 1996 (DAΦNE by 95). KLOE operating by summer 98 at a cost of 51.5 G. Very little computing acquired (1992 1$ $ $ AND Y!!!) KLOE was descoped and slowed down. Ex PM 5000 PM. Less fibers, make do with Poli.Hi.Tec etc. Still KLOE an excellent detector. Thanks to its good design and construction works in difficult conditions. It was lots of work from the small KLOE collaboration. Xmas 98 New Year 99 KLOE enters DAΦNE hall. We were really proud and happy. th Catania, 16 September 2002 Paolo Franzini - KLOE , CSN1 5

6 1999 to today April 14, 1999 KLOE detects e + e e + e and e + e K L K S. Also dcovers that L much lower than claimed. KLOE operates then and today at a very high efficiency, >95% Processing can barely keep up with DAΦNE up to 6 pb 1 /day Q-cal (not in the original proposal). Needs some upgrade de/dx measurement in DC. Installed th year. In 99 2 pb 1 delivered. Some nice events. In 2000 L still very low: 20 pb 1. The first KLOE physics Publhed 5 papers in PL in 2002, after acquiring sufficient CPU power for reconstruction, analys, MC... reprocessing In 2001 L improved, but the already high bckgnd hit the sky. Too much load on: library, processing, reprocessing In 2002 L improved and background much reduced. th Catania, 16 September 2002 Paolo Franzini - KLOE , CSN1 6

7 2. The Cost of Background 1. Tracking and clustering efficiency 2. Trigger rate: reconstruction and storage cost 3. Accidentals background to physics 4. 01, 02, 03 (% of contaminated events) F (bckgnd) B, for any L. Trigger rate can be reduced at an additional loss of efficiency 2001 Hardened the trigger at a cost in efficicency. 99.2% 94% for K S π + π +K e3,µ3,π2. Almost 10 for ζ=1 eff. Toward the end of 2001 improved L/B reduced the load on recostruction. For B=( khz), eff(tracking) drops by 4.5%. th Catania, 16 September 2002 Paolo Franzini - KLOE , CSN1 7

8 2002 e e + DC, 1 st layer P P 2002 P f khz khz 2001 f khz khz f khz khz Can process up to 6 pb 1 /day but it s very marginal. th Catania, 16 September 2002 Paolo Franzini - KLOE , CSN1 8

9 The search for K S π 0 π 0 π M(3 0 ) (MeV) rd 2002, 10 pb 4 Ev , 100 pb 77 Ev M(3 ) (MeV) th Catania, 16 September 2002 Paolo Franzini - KLOE , CSN1 9

10 40 L - 1/ b/s To date 1 day /4 5/4 6/3 7/3 8/2 9/1 10/1 10/31 11/30 1-May 31-May 30-Jun 30-Jul 29-Aug th Catania, 16 September 2002 Paolo Franzini - KLOE , CSN1 10

11 200 d t - 1/pb May 31-May 30-Jun 30-Jul 29-Aug th Catania, 16 September 2002 Paolo Franzini - KLOE , CSN1 11

12 100 L, 1/pb/month th Catania, 16 September 2002 Paolo Franzini - KLOE , CSN1 12

13 2002 DAΦNE in 2003 will deliver >10 pb 1 /day th Catania, 16 September 2002 Paolo Franzini - KLOE , CSN1 13

14 Trigger thresholds Eth=50 MeV Eth=100 MeV 200 Beams Barrel MeV End Cap th Catania, 16 September 2002 Paolo Franzini - KLOE , CSN1 14

15 Trigger rates in 2002 High Thr. Nominal Thr. khz khz T L DAΦNE off φ Bhabha Th larger than 2001, but acceptable at higher L CR, can be lowered to 0.5 khz 2003 Computing power: 2-3 for pb 1 /day. REALISTIC The machine background will remain low Without more computing, DAΦNE progress will be in vain th Catania, 16 September 2002 Paolo Franzini - KLOE , CSN1 15

16 KLOE - Archiviazione dati 26 Agosto Raw 6 Tbytes GONE Raw 22 Tbytes Ricostruiti 12 Tbytes Raw 48 Tbytes Ricostruiti 37 Tbytes Raw 23 Tbytes Ricostruiti 18 Tbytes More storage needed soon (referees) 110 TB available for 2003 th Catania, 16 September 2002 Paolo Franzini - KLOE , CSN1 16

17 Offline Farm CPUs 10 4 E450 User/MonteCarlo/DST 7/ B80 User/Reconstruction 6/2001 Servers 2 H80 TSM(Library) + NFS(Dk) Servers 12/2001 Dks 3TB 7/ Servers 2 H70 AFS Servers 2000 Dks 2TB 2000 Library Magstar 100TB (5000 cassettes) TB drives TB?/2003 Router Catalyst 6000 Gigabit/FE 2002 These facilities are in use 24 hours a day, 365 days a year. They must be on when the machine on They are never idle analys, reprocessing (instal., maint.). th Catania, 16 September 2002 Paolo Franzini - KLOE , CSN1 17

18 Offline Farm Potenza di Calcolo Totale - Equivalente a CPU H80 Partizione nominale : 20% Utenti/Gruppi di anali (23 CPUs) 12% MC/Generazione-ricostruzione (13 CPUs) 68% Ricostruzione/Produzione DST (76 CPUs) Ricostruzione Ago 02 : 47 triggers/s/cpu media 35CPU (fino a 50) Estrapolando a fondi L 2 34 triggers/s/cpu ed in media 55CPU L 3 28 triggers/s/cpu ed in media 80CPU usate th Catania, 16 September 2002 Paolo Franzini - KLOE , CSN1 18

19 In 2003 DAΦNE will pass the 100 µb 1 /s mark, 77 reached, nominally 20% of design L. For L> , i.e. L>9 pb 1 /d, including MC, calibration, analys... we need 2.5 in CPU power or +1.5 CPU-P +10 Tbyte of dk space Reprocessing and raw data storage might still be necessary. We have now collected 2% of the approved first KLOE program. We have operated so far under very different L and B condition and we want to recover the lost efficiencies. th Catania, 16 September 2002 Paolo Franzini - KLOE , CSN1 19

20 New Physics (Not in milestones) K L γγ, from about 150 pb 1, 2001 data BR EASY S=8751 B=1514 /dof=104/100 S=8679 B=853 /dof=65/ M( ) MeV th Catania, 16 September 2002 Paolo Franzini - KLOE , CSN1 20

21 τ KL check, will improve accuracy τ KL K L ns ( PDG 51.7 ) events 2 /dof =93/ t (ns) th Catania, 16 September 2002 Paolo Franzini - KLOE , CSN1 21

22 η γγγ (π + π π 0 ) BR(η γγγ)< % CL From 50 pb 1, 2001 data High background BR(η γγγ)< % CL Crystal ball, 2002 preliminary New analys underway, need MC. th Catania, 16 September 2002 Paolo Franzini - KLOE , CSN1 22

23 K S π + π π 0 NOT C\P\ BR HARD Preliminary study with 2001 data shows it s feasible Need MC th Catania, 16 September 2002 Paolo Franzini - KLOE , CSN1 23

24 Kaon interferometry 2001 data, 182 pb 1 e + e φ K 0 +K 0 (π + π ) 1 +(π + π ) 2 First Time Observation 150 Beam pipe regeneration Events /dof 43.89/47 N decay m ns 1 N pipe t t K S th Catania, 16 September 2002 Paolo Franzini - KLOE , CSN1 24

25 Understanding KLOE: DAΦNE Energy spread Use p(k S ) and β(k L ), two independent values of w(daφne) From w 1 + w 2, beam spread dependent and w 1 w 2 b. s. ind.: Intrinsic DA NE energy spread 1.0 rms( W) MeV W=1019 MeV, W 0.65 Mev E=510, E 0.4 MeV Run nr th Catania, 16 September 2002 Paolo Franzini - KLOE , CSN1 25

26 M(K S ) Events/200 kev 430 kev m(φ) 2m(K S ) = 26 MeV (1/2m(φ)) 2 = m 2 (K S )+p 2 K S δm KLOE 270 kev δm DAΦNE 220 kev δm RadCor 20 kev MeV mk ( S) mk ( S ) MeV CMD-2 NA48 KLOE m(k S ) = ± ± MeV Who right? QED rad corr are site dependent th Catania, 16 September 2002 Paolo Franzini - KLOE , CSN1 26

27 σ(e + e φ) from K ± σ phys (e + e φ)=3.2±0.1 µb Independent of tag efficiency We have hints of dcrepancies with Novosibirsk BR s th Catania, 16 September 2002 Paolo Franzini - KLOE , CSN1 27

28 Milestones Marzo 02 Ricostruzione dei dati del 2001 Done 2. Maggio 02 DST dei dati 2001 per l anali Done, except for charged kaons waiting for new tracking code. All procedures tested, ready to go. Needs <3 months on one machine, 3 days on all. th Catania, 16 September 2002 Paolo Franzini - KLOE , CSN1 28

29 Milestones Dicembre 02 Manutenzione di KLOE e presa dati 02 Data taking from 1 May /pb OFFICIAL DAFNE LOG Delivered 248 Logged /03/02 12/09/02 Note: we do not take data with L<20 µb 1 s 1, not all logged L usable. DAΦNE L includes machine study. Eff.>96%. But it costs blood... th Catania, 16 September 2002 Paolo Franzini - KLOE , CSN1 29

30 Milestone Continuous improvements of KLOE calibration. Improved specific ionization corrections, approaching test beam accuracy. Major weakness HV CAEN power supplies for phototubes: one PS/wk for 5000 PS s. 16 failed in Aug. Have 11 spares. CAEN will not repair till after end run!! Cf. CUSB. 0 failures/5 years, for 1000 PS. ns Aug 9 Sep EMC Time SIGMA before/after calibration nrun ns nrun ns nrun th Catania, 16 September 2002 Paolo Franzini - KLOE , CSN1 30

31 Milestones Dicembre 02 BR(K S πe ± ν) 7. Dicembre 02 BR(K S π + π e π 0 π 0 ) All new event finder, efficiency, corrections etc. programs written and debugged. Ready for final pass end September. Will get also A S l =(e+ e )/(e + + e ), never measured before th Catania, 16 September 2002 Paolo Franzini - KLOE , CSN1 31

32 Evts/MeV June pb pb e 1760 e Evts/MeV e 1766 e E -20 ms - P 0 ms (MeV) Ems - P 0 ms (MeV) th Catania, 16 September 2002 Paolo Franzini - KLOE , CSN1 32

33 Milestones Dicembre 02 Mura di φ ρπ Last refinements to correct for kev systematics error in M, stattical error 500 kev. Complete. 6. Dicembre 02 BR(φ γ+a 0, f 0 ) OK The KLOE results are very important for the understanding of the low energy q q and q qq q states as proved by much recent theoretical interest. Improving the stattical accuracy and systematic errors which still scale as n of fundamental importance. Also φ η, η + γ th Catania, 16 September 2002 Paolo Franzini - KLOE , CSN1 33

34 φ a 0 γ ηπ 0 γ π + π π 0 π 0 γ 2 charged+5γ 2001, 142 1/pb 00 01, norm by L th Catania, 16 September 2002 Paolo Franzini - KLOE , CSN1 34

35 Evts/(10 MeV) data 60 pb -1 φ a 0 γ ηπ 0 γ γγπ 0 γ 5γ 2001, 60 1/pb 00 01, norm by L Evts M ηπ (MeV) Confirm 2000 results Better determination of parameters M ηπ (MeV) th Catania, 16 September 2002 Paolo Franzini - KLOE , CSN1 35

36 φ η γ ηπ 0 γ π + π 3γ Events/4 MeV BR(φ η γ ) 150 pb M( ) MeV th Catania, 16 September 2002 Paolo Franzini - KLOE , CSN1 36

37 8. Dicembre 02 BR(K L π + π e π 0 π 0 ) OK 9. Dicembre 02 BR(K ± µν, π ± π 0 ) OK?? th Catania, 16 September 2002 Paolo Franzini - KLOE , CSN1 37

38 10. Dicembre 02 Mura preliminare di σ(e + e π + π ) OK Also pion form factor Problem theory, i.e. rad cor 1. New problems with calculations of muon anomaly 2. Need a good QED calculation of e + e π + π γ 3. The above needs an analytic form for ππγ ver, i.e. the pion form factor, sort of vicious circle 4. Need a good QED calculation of Bhabha scatt. at low E, large θ 5. Finally find σ(e + e π + π nγ), n=0,1... th Catania, 16 September 2002 Paolo Franzini - KLOE , CSN1 38

39 The muon anomaly and γ ππ From τ data: [a exp µ a th µ ] = 110 ± 80 exp ± 113 th τ 2σ From e + e data: [a exp µ a th µ ] = 368 ± 80 exp ± 113 th e + e 1.8σ A 4% difference due to an unaccounted ospin hard to believe in very likely either the e + e or τ data wrong. Kirill Melnikov See later th Catania, 16 September 2002 Paolo Franzini - KLOE , CSN1 39

40 th Catania, 16 September 2002 Paolo Franzini - KLOE , CSN1 40

41 th Catania, 16 September 2002 Paolo Franzini - KLOE , CSN1 41

42 Milestones for Ricostruzione dati /4 2. Lavoro su KLOE per nuova regione di interazione 1/4 3. Upgrade del Q-Cal 1/4 4. Preparazione DST per anali 1/4 5. Upgrade del filtro di livello 3 1/4 6. Monte Carlo per anali /4 7. BR, σ per K ± 2-4/4 8. Anali con errori stematici ridotti, dati /4 9. Manutenzione e presa dati nel 2003?-4/4 th Catania, 16 September 2002 Paolo Franzini - KLOE , CSN1 42

43 Remarks I mentioned that the I-spin rotation (π + π ) (π ± π 0 ), relating e + e π + π and W ± π ± π 0, leads to an 4% difference. A similar rotation, (K ± π 0 ) (K L π ± ), appears when we consider the semileptonic decays K ± π 0 (eν) and K L π ± (eν). Ignoring I-spin corrections, we have: Γ(K L,e3 )=Γ(K S,e3 )=2 Γ(K ± e3 ). Correcting for phase space, 0.8%, the measured values give: 2Γ + Γ L =(3.66 ± 0.06)% Γ L Again 4%, too big??? To get V us to better than 1.1%, 39 years after its introduction, we need that correction. th Catania, 16 September 2002 Paolo Franzini - KLOE , CSN1 43

44 In some kind of jargon one must compute corrections due to I-spin and SU(3) flavor breaking. In another, we need QCD calculation of the hadronic matrix elements. Progress slow but coming. The KLOE program centered on th problem. Comparon of K L, K S and K ± semileptonic decays with KLOE can verify the correctness of the calculations, to accuracies well beyond present theoretical ablilities. A new measurement of the neutral pion current coupling to the photon underway, using radiative return to reach the range 2m π <M(ππ) < 1 GeV without an energy scan. th Catania, 16 September 2002 Paolo Franzini - KLOE , CSN1 44

45 Both cases above are example of contributions to fundamental problems in physics. QCD a beautiful theory but very hard to use especially at low energy. Good measurements are at least an inducement to try harder. Th also very much the case with precion measurements of K ππ rates and the study of scalar and pseudoscalar meson via φ-radiative decays. We expect in 2003 a very improved DAΦNE. We need more computing power for that. We need it even at lower luminosity, in order to recover the efficiency losses in the trigger. It would be sad if we couldn t collect those data! th Catania, 16 September 2002 Paolo Franzini - KLOE , CSN1 45