M. Primavera 2 nd KLOE Physics Workshop, 10 th -12 th june 2002 Otranto (LE) 1 Perspectives on 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, E. Gorini, V. Kulikov, M. Martemianov, L. Passalacqua, V. Patera, M. Primavera, G. Saracino, B. Sciascia, A. Ventura

M. Primavera 2 nd KLOE Physics Workshop, 10 th -12 th june 2002 Otranto (LE) 2 Some Initial Remarks  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?”  No description about details of the analysis  Not all analysis at the same stage! Some numbers could change if new inputs

M. Primavera 2 nd KLOE Physics Workshop, 10 th -12 th june 2002 Otranto (LE) 3  K e3 and K  3 decays,  V us “Shopping list”  K  masses and lifetimes  BR’s : K  , K     0, K   3 , K  l4  Conclusions  Cross Section (see Maxim’s talk)  Dalitz plots of K     0  0, K      +  -

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

M. Primavera 2 nd KLOE Physics Workshop, 10 th -12 th june 2002 Otranto (LE) 5 K ± Life Time World Data (in ns)  (fit),  (average) (PDG)  (KOPTEV ) K at rest  (KOPTEV ) K at rest  (OTT ) K at rest  (LOBKOWICZ ) K in flight  (FITCH ) K at rest  CPT measurement : World data (%) 0.11  0.09 (Average) (PDG2001)  (best meas., ‘69)

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

M. Primavera 2 nd KLOE Physics Workshop, 10 th -12 th june 2002 Otranto (LE) 7 Branching ratios Two body decays in K + K  - stream K+K+ KK  ++ 11 22 For 500 pb -1 we have (rec.) approx. 300*10 6   K + K 

M. Primavera 2 nd KLOE Physics Workshop, 10 th -12 th june 2002 Otranto (LE) 8 Ratio  o /  Zeller Auerbach Weissenberg (ITEP) Usher (CERN) KLOE PDG 2001 World data  (fit)  (Average) (PDG)  (USHER ) (45k)  (WEISSENBERG )  (ZELLER )  (AERBACH )  (stat.)+(?)(sys.) (KLOE preliminary, 11.2pb -1 )

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

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

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

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

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

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

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

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

M. Primavera 2 nd KLOE Physics Workshop, 10 th -12 th june 2002 Otranto (LE) 17 K l4 Decays  Good place to study hadronic physics and to test  PT but low BR (~10 -5 ) : K +   +  - e + e 3.9  K +   +  -  +  1.4  K +   0  0 e + e 2.1  K L 0   0   e  e 5.2   Form factors can be extracted from the decay rate as partial wave expansions containing the  elastic scattering phase shifts (  I l )  K + e4 studied at CERN SPS (1977) by using rec. ev. KLOE needs at least 10  stat. to be significative, but

M. Primavera 2 nd KLOE Physics Workshop, 10 th -12 th june 2002 Otranto (LE) 18 Study on K ±  0  0 e ± e Highest statistics in:  (  0  0 e ± e )/  (  0 e ± e ) = (4.2±1.0)  10 –4 (BOLOTOV 86, 25 evts) K ±  e ±  0  0 e studies World Data (  ) 2.1  0.4 (fit) 2.54  0.89 (average) (Barmin 88,10 ev.) 1515 selected K e4 events over MC generated   MC  1.48%  ~0.9 K e4 /pb –1 are expected on data Only 2 K e4 found in 6.33 pb –1  ~150 ev in 500pb –1 m e m  Data m  m e MC rec

M. Primavera 2 nd KLOE Physics Workshop, 10 th -12 th june 2002 Otranto (LE) 19 V us from K l3 decays  While theory provides the knowledge of form factors at q 2 =0: + measured in K e3 and K  3, 0 only in K  3 (suppressed in K e3 by the factor (m e /M K ) 2 )  Assuming a linear expansion of the evolution of form factors f + K  and f 0 K  400 k 3 M3 M  obtained by the measurement of

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

M. Primavera 2 nd KLOE Physics Workshop, 10 th -12 th june 2002 Otranto (LE) 21 V us with K + e3 decays  Contributions to the total error 0.22% (from the most recent measur.of 

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

M. Primavera 2 nd KLOE Physics Workshop, 10 th -12 th june 2002 Otranto (LE) 23 CP  ASYMM. (g + - g - ) / (g + + g - ) Theory provides A g,A g 0 ~10 -6 up to (more effordable than A  (  ’) ) K ±  ±  0  0 measuring branching ratio and Dalitz plot parameters s i = ( P K – P i ) 2 i = 1,2,3 s 0 =  i s i / 3 = (m K 2 + m  2 + 2m  ° 2 ) / 3  X = (s 1 – s 2 ) / m  2 Y = (s 3 – s 0 ) / m  2 F(X,Y;g,h,k) = 1+gY+hY 2 +kX 2 Dalitz plots parameters in  (  ’) decays A g measured (-7±5)  with ~ 10 6 ev.(KLOE is out), A g 0 never measured 1 year of data (~ 10 9  decays and ~ 10 8  ’)   A g,  A g 0 ~ 10 -4

M. Primavera 2 nd KLOE Physics Workshop, 10 th -12 th june 2002 Otranto (LE) 24 QUADRATIC COEFFICIENT k ±0.0045± (BATUSOV 98) ASYMMETRY (g + - g - ) / (g + + g - ) NEVER MEASURED 6.33 pb -1  ~15500 K  °  ° (  MC normalized) KLOE 6.33 pb –1 PDG g0.607± ±0.031 h0.026± ±0.018 k0.0080± ± VERY PRELIMINARY

M. Primavera 2 nd KLOE Physics Workshop, 10 th -12 th june 2002 Otranto (LE) 25 Conclusions  We can improve life times, absolute BR’s and V us knowledge, keeping well under control systematics  We cannot do much more on charged K masses  CP viol. in partial decay rates (A  (  ’ ) is out  We can measure A g 0 (but should be done before NA48 !)

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

M. Primavera 2 nd KLOE Physics Workshop, 10 th -12 th june 2002 Otranto (LE) 27 Present statistics Experimental Data Selection: K ±, 1075 K ± 3  MCstream1K3p Generated K ±  all 980k800k Generated K ±  ±  +  – 54.8k422k Selection : K ±, 352 K ± 3  3.16 pb -1 (July 2000, DBV4)

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

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

M. Primavera 2 nd KLOE Physics Workshop, 10 th -12 th june 2002 Otranto (LE) 30 Statistics analized 3.16 pb -1 (July 2000, DBV4) Experimental Data Selection: K ±, 869 K ±  ±  0  0 MCstream1K3p0 Generated K ±  all 980k560k Generated K ±  ±  0  k285k Selection : K ±, 347 K ±  ±  0  0

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

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

M. Primavera 2 nd KLOE Physics Workshop, 10 th -12 th 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  0 measuring branching ratio and Dalitz plot parameters

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

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

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

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

M. Primavera 2 nd KLOE Physics Workshop, 10 th -12 th june 2002 Otranto (LE) 38 Ratio  o /  Ratio tagging   peak window 225 MeV/c < P CM < 245 MeV/c   peak window 195 MeV/c < P CM < 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 < P K < 120 MeV/c CMS  momentum spectrum for  + K  decay    +  –, e ±  0  ±  0,    0  0   o

M. Primavera 2 nd KLOE Physics Workshop, 10 th -12 th 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 