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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,

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P erspectives o n charged K physics in KLOE

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  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)

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