1 / 39

P erspectives o n charged K physics in KLOE

P erspectives o n charged K physics in KLOE 2 nd KLOE Physics Workshop , 10 th -12 th june 2002 Otranto (LE) M. Primavera for the Charged K Group : P. Branchini, V. Casavola, E. De Lucia, P. De Simone,

zonta
Download Presentation

P erspectives o n charged K physics in KLOE

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Perspectives on charged K physics in KLOE 2nd KLOE Physics Workshop, 10th-12th june 2002 Otranto (LE) M. Primavera for the Charged K Group: P. Branchini, V. Casavola, E. De Lucia, P. De Simone, E. Gorini, V. Kulikov, M. Martemianov, L. Passalacqua, V. Patera, M. Primavera, G. Saracino, B. Sciascia, A. Ventura M. Primavera 2nd KLOE Physics Workshop, 10th-12th june 2002 Otranto (LE)

  2. Some Initial Remarks • No description about details of the analysis • Nothing concerning systematics • Just a “statistical exercise” based on preliminary results of all the analysis performed up to now extrapolating it to 500 pb-1 where KLOE can give significative impr.s in the present “K± scenario?” • Not all analysis at the same stage! Some numbers could change if new inputs M. Primavera 2nd KLOE Physics Workshop, 10th-12th june 2002 Otranto (LE)

  3. “Shopping list” • FCross Section (see Maxim’s talk) • Kmasses and lifetimes • BR’s : K, K 0, K 3, Kl4 • Ke3 and Km3 decays, DVus • Dalitz plots of K00, K  + - • Conclusions M. Primavera 2nd KLOE Physics Workshop, 10th-12th june 2002 Otranto (LE)

  4. K± Mass • World Data (in MeV) • 493.677 0.016 (fit) (PDG2001) • 493.677  0.013 (average) CPT measurement : Kpp+p- • World data (in MeV) • -0.032  0.090 (Ford,’72,1.5M) • Limited by the knowledge of m p+ - m p- ( 70keV) =493.6 MeV/c2 =0.9 MeV/c2 Data MC =494.2 MeV/c2 =1.2 MeV/c2 Stat.:DM ~ 2keV….but we are limited by DC calib.(Dp/p~10-4) We can do better by using F(?) Invariant mass of selected secondary particles triplets M. Primavera 2nd KLOE Physics Workshop, 10th-12th june 2002 Otranto (LE)

  5. K± Life Time • World Data (in ns) • 12.385  0.024 (fit), 12.385  0.025 (average) (PDG) • 12.451  0.030 (KOPTEV - 1995) K at rest • 12.368  0.041 (KOPTEV - 1995) K at rest • 12.380  0.016 (OTT - 1971) K at rest • 12.272  0.036 (LOBKOWICZ - 1969) K in flight • 12.443  0.038 (FITCH - 1965) K at rest • CPT measurement : World data (%) 0.11  0.09 (Average) (PDG2001) 0.090  0.078 (best meas., ‘69) M. Primavera 2nd KLOE Physics Workshop, 10th-12th june 2002 Otranto (LE)

  6. Normalized K time distribution # Data / e(t) 17.5 pb–1 (end 2000) • (ns)=12.40±0.08 (stat)+(?)(sys) t (ns) 500 pb-1 stat  0.015 ns M. Primavera 2nd KLOE Physics Workshop, 10th-12th june 2002 Otranto (LE)

  7. Branching ratios 1 + K+ K 2  For 500 pb-1 we have (rec.) approx. 300*106K+K Two body decays in K+K- stream M. Primavera 2nd KLOE Physics Workshop, 10th-12th june 2002 Otranto (LE)

  8. Ratio o/ • World data • 0.3334  0.0028 (fit) • 0.3316  0.0032 (Average) (PDG) • 0.3329  0.0047 (USHER - 1992) (45k) • 0.3355  0.0057 (WEISSENBERG - 1976) • 0.305  0.018 (ZELLER - 1969) • 0.3277  0.0065 (AERBACH - 1967) Weissenberg (ITEP) Usher (CERN) Auerbach KLOE PDG 2001 Zeller 0.3306  0.0012 (stat.)+(?)(sys.) (KLOE preliminary, 11.2pb-1) M. Primavera 2nd KLOE Physics Workshop, 10th-12th june 2002 Otranto (LE)

  9. Exp. ratio (o/)  2  ndf = 0.532 for 16 points  + – , e±0 ± 0,  0 0 o Ratio o/ CMSmomentum spectrum for +K decay DR/R ≈ 1% (world average)  0.5‰ (500 pb-1only stat!) M. Primavera 2nd KLOE Physics Workshop, 10th-12th june 2002 Otranto (LE)

  10. Branching ratio o • KLOE can measure absolute BR’s • World Data, PDG2001 (10 -2 ) • 21.17  0.14 (fit) • 21.18  0.28 (best exp.,16k) Exp. BR(o) Preliminary estimation for total statistics: 2.6 pb–1 (end 2000) 20.560.26(stat.)+(?)(sys) DBR/BR ≈ 1.3% (best meas.)  1‰ (500 pb-1only stat!) M. Primavera 2nd KLOE Physics Workshop, 10th-12th june 2002 Otranto (LE)

  11. Branching ratio  Exp. BR() • World Data, PDG2001 (10 -2 ) • 63.51  0.18 (fit) • 63.24  0.44 (best exp.,62k) Preliminary estimation for total statistics: 2.6 pb–1 (end 2000) 61.260.50(stat.)+(?)(sys) DBR/BR ≈ 0.7% (best meas.)  0.6‰ (500 pb-1only stat!) M. Primavera 2nd KLOE Physics Workshop, 10th-12th june 2002 Otranto (LE)

  12. K±±+– (t±) and K±±00 (t’±) decays • Extremely interesting decays from direct CP point of view, by measuring • World Data, PDG2001 • (0.7  1.2)10 -3(At world average) • (0  6 )10 -3(At’ world average) • … unfortunately theory provides O(10-8) and KLOE could have sensitivities down to ~ 10-5with statistics comparable to CP to 10-4 in neutral kaons!  with 500 pb-1and present t(t’) we cannot do better than PDG on At’, At M. Primavera 2nd KLOE Physics Workshop, 10th-12th june 2002 Otranto (LE)

  13. K±±+– branching ratio • World Data ( 10 -2 ) • 5.59  0.05 (fit), 5.52  0.10 (average) (PDG2001) • 5.34  0.21 (PANDOULAS - 1970) • 5.71  0.15 (DEMARCO - 1965) • 6.0  0.4 (YOUNG - 1965) • 5.54  0.12 (CALLAHAN - 1964, 2332ev.) • 5.1  0.2 (SHAKLEE - 1964) • 5.7  0.3 (ROE - 1961) Without tagging! M. Primavera 2nd KLOE Physics Workshop, 10th-12th june 2002 Otranto (LE)

  14. K±±+– decay Data MC Data MC 85MeV/c 85MeV/c =493.6 MeV/c2 =0.9 MeV/c2 =494.2 MeV/c2 =1.2 MeV/c2 Momentum of selected secondary particles Invariant mass of selected secondary particles triplets M. Primavera 2nd KLOE Physics Workshop, 10th-12th june 2002 Otranto (LE)

  15. K±±00 branching ratio • World Data ( 10 -2 ) • 1.73  0.04 (fit) • 1.77  0.07 (average) (PDG) • 1.84  0.06 (CHIANG - 1972) • 1.53  0.11 (PANDOULAS - 1970) • 1.8  0.2 (SHAKLEE - 1964) • 1.7  0.2 (ROE - 1961) Best measur. has 3.5% error, And it’s based on only 1307 events M. Primavera 2nd KLOE Physics Workshop, 10th-12th june 2002 Otranto (LE)

  16. K±±00 branching ratio • Preliminary on 6.33 pb-1(December 2001) K±±00measuring branching ratio and Dalitz plot parameters M. Primavera 2nd KLOE Physics Workshop, 10th-12th june 2002 Otranto (LE)

  17. Kl4 Decays • Good place to study hadronic physics and to test cPT but low BR (~10 -5) : K+  p+p-e+ne 3.910-5 K+  p+p-m+nm1.410-5 K+  p0p0e+ne 2.110-5 KL0  p0pene 5.210-5 • Form factors can be extracted from the decay rate as partial wave expansions containing the pp elastic scattering phase shifts (dIl) • K+e4 studied at CERN SPS (1977) by using 30000 rec. ev. KLOE needs at least 10stat. to be significative, but M. Primavera 2nd KLOE Physics Workshop, 10th-12th june 2002 Otranto (LE)

  18. m me K±e±00 ne studies • World Data ( 10 -5 ) • 2.1  0.4 (fit) • 2.54  0.89 (average) (Barmin 88,10 ev.) Highest statistics in: (00e±e)/(0e±e) = (4.2±1.0)10–4 (BOLOTOV 86, 25 evts) 1515 selected Ke4 events over 102600 MC generated  MC1.48%  ~0.9 Ke4/pb–1 are expected on data Only2 Ke4 found in 6.33 pb–1  ~150 ev in 500pb–1 Data MC rec m M. Primavera 2nd KLOE Physics Workshop, 10th-12th june 2002 Otranto (LE) Study on K±00e±e me

  19. 3M 400 k Vusfrom Kl3 decays • obtained by the measurement of • Assuming a linear expansion of the evolution of form factors f+Kp and f0Kp • While theory provides the knowledge of form factors at q2=0: l+ measured in Ke3 and Km3, l0 only in Km3 (suppressed in Ke3 by the factor (me/MK)2 ) M. Primavera 2nd KLOE Physics Workshop, 10th-12th june 2002 Otranto (LE)

  20. Experimental status of K+e3 and K+3 decays 2345,’72 3516, ‘72 (ISTRA+) 112 k (ISTRA+) (KEK-E246) 41 k, 2001-2002 ≥100 k, 2001 M. Primavera 2nd KLOE Physics Workshop, 10th-12th june 2002 Otranto (LE)

  21. Vus with K+e3 decays • Contributions to the total error 0.22% (from the most recent measur.of Dl/l) M. Primavera 2nd KLOE Physics Workshop, 10th-12th june 2002 Otranto (LE)

  22. Preliminary 20 pb-1 K+e3 yield in KLOE (stat. only) M. Primavera 2nd KLOE Physics Workshop, 10th-12th june 2002 Otranto (LE)

  23. Dalitz plots parameters in t(t’) decays s0 = isi/3 = (mK2 + m2 +2m°2)/3  X = (s1 – s2)/m2 Y = (s3 – s0)/m2 si = (PK – Pi)2 i = 1,2,3 F(X,Y;g,h,k) = 1+gY+hY2+kX2 CP  ASYMM. (g+- g-) / (g++ g-) Theory provides Ag,Ag0 ~10-6 up to 10-4 (more effordable than At(t’)) Ag measured (-7±5) 10-3 with ~ 106 ev.(KLOE is out), Ag0never measured 1 year of data taking @NA48’ (~ 109 t decays and ~ 108 t’) D Ag,D Ag0 ~ 10-4 K±±00measuring branching ratio and Dalitz plot parameters M. Primavera 2nd KLOE Physics Workshop, 10th-12th june 2002 Otranto (LE)

  24. QUADRATIC COEFFICIENTk 0.0197±0.0045±0.0029(BATUSOV 98) 6.33 pb-1  ~15500 K°° (MCnormalized) VERY PRELIMINARY ASYMMETRY (g+- g-) / (g++ g-) NEVER MEASURED M. Primavera 2nd KLOE Physics Workshop, 10th-12th june 2002 Otranto (LE)

  25. Conclusions • We cannot do much more on charged K masses • We can improve life times, absolute BR’s and Vus knowledge, keeping well under control systematics • CP viol. in partial decay rates (At(t’) is out • We can measure Ag0(but should be done before NA48 !) M. Primavera 2nd KLOE Physics Workshop, 10th-12th june 2002 Otranto (LE)

  26. Vus with K+e3 decays (new) M. Primavera 2nd KLOE Physics Workshop, 10th-12th june 2002 Otranto (LE)

  27. Present statistics Experimental Data Selection: 1099682 K± , 1075 K±3 3.16 pb-1(July 2000, DBV4) Selection: 299880 K±, 352 K±3 M. Primavera 2nd KLOE Physics Workshop, 10th-12th june 2002 Otranto (LE)

  28. Selected Kaons on MC M. Primavera 2nd KLOE Physics Workshop, 10th-12th june 2002 Otranto (LE)

  29. ±±+–Branching Ratio (preliminary estimation) * ** *Background contamination negligible (<0.3% from MC) **0.34% subtraction KPMFILT selecting nonK+K– events (MC) M. Primavera 2nd KLOE Physics Workshop, 10th-12th june 2002 Otranto (LE)

  30. Statistics analized Experimental Data Selection: 1099682 K± , 869 K±±00 3.16 pb-1(July 2000, DBV4) Selection: 299880 K±, 347 K±±00 M. Primavera 2nd KLOE Physics Workshop, 10th-12th june 2002 Otranto (LE)

  31. Selected Kaons on MC M. Primavera 2nd KLOE Physics Workshop, 10th-12th june 2002 Otranto (LE)

  32. ±±00Branching Ratio (very preliminary estimation) * ** *Background contamination subtracted (~0.3% in MCpreliminary) **0.34% subtraction KPMFILT selecting nonK+K– events (MC) M. Primavera 2nd KLOE Physics Workshop, 10th-12th june 2002 Otranto (LE)

  33. Filter algorithm (I)Preliminary requirements • Cosmic Veto  (DC+EMC) Trigger • Any of the 5 EvCl algorithms • a 2-tracks vertex in the DC involving a K± track • Distance between the two tracks’ first/last hit < 50 cm • Angle at vertex between the two tracks > 2° K±±00measuring branching ratio and Dalitz plot parameters M. Primavera 2nd KLOE Physics Workshop, 10th-12th june 2002 Otranto (LE)

  34. Filter algorithm (II)Further requirements • 4 “ontime” non-associated clusters coming from the charged vertex: |ti–tj–(Li–Lj)/c|<3t(Ei,Ej) i,j=1,..,4 • Considered the best possible quartet of clusters: 80 MeV < m12,m34 < 190 MeV ( 3m cut ) • Charged product track momentum: |pdau| < 135 MeV in K± frame all contamination ~0.4% (MC) K±±00measuring branching ratio and Dalitz plot parameters M. Primavera 2nd KLOE Physics Workshop, 10th-12th june 2002 Otranto (LE)

  35. Tagging strategies 1) K±±0 • Daughter momentum: 199 MeV < |pdau| < 211 MeV in K frame • Missing mass at K vertex: 90 MeV < mm < 180 MeV • 2 ontime non-associated clusters: 120 MeV < m < 150 MeV all contamination ~0.35% (MC) 2) K±± • Daughter momentum: 226 MeV < |pdau| < 245 MeV in K frame • Missing mass at K vertex: |mm|< 5 MeV all contamination ~0.3% (MC) K±±00measuring branching ratio and Dalitz plot parameters M. Primavera 2nd KLOE Physics Workshop, 10th-12th june 2002 Otranto (LE)

  36. BR measurement method WORK IN PROGRESS ±00 1 Ntag [Nobs]tag [ ]tag BR(K±00) = tag = 0,  ±00 • [ ]tag  does not depend onFILFO ,EvCl ,tag • independence from trigto be tested ±00     = K(pK) vtx(pK,p)4clu(E)2pairing(E) K±±00measuring branching ratio and Dalitz plot parameters M. Primavera 2nd KLOE Physics Workshop, 10th-12th june 2002 Otranto (LE)

  37. Efficiencies (Data and MC ) Kvs # of non-associated clusters (non-tag, E > 20 MeV) All tag events sample WORK IN PROGRESS vtx(p) 00 events subsample clu (E) 0 events subsample K±±00measuring branching ratio and Dalitz plot parameters M. Primavera 2nd KLOE Physics Workshop, 10th-12th june 2002 Otranto (LE)

  38.   + – , e±0 ± 0,  0 0 o Ratio o/ • Ratio tagging • peak window 225 MeV/c < PCM < 245 MeV/c • peak window 195 MeV/c < PCM < 215 MeV/c • Decay vertex with Rxy > 40 cm • For good trigger efficiency : one kaon track has a decay o • Cut for secondary vertex and secondary momentum 20 MeV/c <Psec < 400 MeV/c • Cut for kaon momentum at decay point 80 MeV/c < PK < 120 MeV/c CMSmomentum spectrum for +K decay M. Primavera 2nd KLOE Physics Workshop, 10th-12th june 2002 Otranto (LE)

  39. Branching ratio of o,   • Branching ratio cuts • Number of K all caluclated as number of decays in secondary monentum window from 20 to 400 MeV/c • Decay vertex with Rxy > 40 cm • peak window and peak window • Using only drift chamber information M. Primavera 2nd KLOE Physics Workshop, 10th-12th june 2002 Otranto (LE)

More Related