Roberto Versaci Heavy Quarks and Leptons '06 – München / 26 1 New results from KLOE Roberto Versaci on behalf of the KLOE collaboration

Roberto Versaci Heavy Quarks and Leptons '06 – München / 26 2 Outline ● KLOE and DAFNE Neutral kaons Charged kaons Hadronic physics Future plans Main K L branching ratios K L  p + p – (g) K L  p e n e form factor K S  p + p - (g) / K S  p 0 p 0 K S  p e n e ; A S ; form factor Lifetime Semileptonic decays K ± ® m ± n m (g) Test of CP, CPT, DS=DQ rule, QM Determination of V US and CP parameters Test of cPT theories

Roberto Versaci Heavy Quarks and Leptons '06 – München / 26 3 Days of run pb -1 KLOE and DAFNE electron-positron collider √s = m f = GeV s(f) ≈ 3 mb ~2.5 fb -1 collected LINAC KLOE e MeV e + Frascati - LNF Decay BR(%) K + K K L K S 34.0 rp+ppp 15.3 hg 1.3

Roberto Versaci Heavy Quarks and Leptons '06 – München / 26 4 KLOE and DAFNE Endcap – Barrel modules Pb / scintillating fibers 4880 PMT p/e PID based on TOF s t = 57 ps / √(E[GeV])  100 ps s E = / √(E[GeV])

Roberto Versaci Heavy Quarks and Leptons '06 – München / 26 5 KLOE and DAFNE Stereo geometry, 4m diameter wires 90% Helium, 10% isobutane s rf = 150 mm, s z = 2 mm s p /p ~ 4 x 10 -3

Roberto Versaci Heavy Quarks and Leptons '06 – München / 26 6 Tagging The f decay at rest provides monochromatic and pure kaon beams The detection of a K guarantees the presence of the K with known momentum  Tag mechanism Normalization to the number of tags allows a precise measurement of absolute BRs K + K x 10 6 /pb -1 p* = 127 MeV/c l ± = 95 cm K L K S 10 6 /pb -1 p* = 110 MeV/c l S = 6 mm l L = 3.4 m K  mnmK  pp0K  mnmK  pp0 K S  p + p - K L interacts in EMC

Roberto Versaci Heavy Quarks and Leptons '06 – München / 26 7 Neutral kaons ● Main K L branching ratios ● K L  p + p – (g) ● K L lifetime ● K L  p e n e form factor ● K S  p + p - (g) / K S  p 0 p 0 ● K S  p e n e ; A S ; form factor Data sample between 200 and 400 pb -1

Roberto Versaci Heavy Quarks and Leptons '06 – München / 26 8 Main K L BRs BR (K L  pen e ) = ± ± BR (K L  pmn m ) = ± ± BR (K L  p 0 p 0 p 0 ) = ± ± BR (K L  p + p - p 0 ) = ± ± Error dominated by error in t L, needed for geometrical acceptance PLB 632 (2006) BR( pen + pmn + p + p - p 0 + p 0 p 0 p 0 ) from KLOE + BR( p + p - + p 0 p 0 + g g ) from PDG'04 = ± ~ 0.36 %

Roberto Versaci Heavy Quarks and Leptons '06 – München / 26 9 Main K L BRs BR (K L  pen e ) = ± ± k evts BR (K L  pmn m ) = ± ± k evts BR (K L  p 0 p 0 p 0 ) = ± ± k evts BR (K L  p + p - p 0 ) = ± ± k evts Normalize S x BR(K L  x) = 1 and solve for t L taking KLOE BRs & BR( p + p - + p 0 p 0 + gg ) from PDG'04 Average with KLOE direct measurement PLB 626 (2005) : PLB 632 (2006) t L = (50.72  0.17  0.33 ) ns t L = (50.84  0.23 ) ns

Roberto Versaci Heavy Quarks and Leptons '06 – München / K L  p en e form factor Form factor expansion: ● linear ● quadratic one pole parametrization: PLB 636 (2006) M V = ( 870  6  7 ) MeV P(c 2 ) = l + = (28.6  0.5  0.4)  c 2 / dof = 330 / 363 P(c 2 ) = 0.89 l + ' = ( 25.5  1.5  1.0 )  l + '' = ( 1.4  0.7  0.4 )  c 2 / dof = 325 / 362 P(c 2 ) = 0.92 f + (t) = 1 + l + [t/m p 2 ] f + (t) = 1 + l + ' [t/m p 2 ] + ½ l + '' [t/m p 2 ] 2 LinearQuadratic M V 2 M V 2 - t t/m p 2

Roberto Versaci Heavy Quarks and Leptons '06 – München / Plus other measurements |e| = (2.216  0.013)  ● Measurement of the ratio BR (K L  p + p – ) / BR (K L  p m n m ) ● BR (K L  p m n m ) taken from KLOE measurement PLB 638 (2006) K L  p + p – (g) BR (K L  p + p - ) =  stat  syst √(E 2 miss +p 2 miss )(MeV)

Roberto Versaci Heavy Quarks and Leptons '06 – München / Averaged with KLOE '02 Common syst. accounted for ● K S  p + p - (g) : 2 tracks from the IP ● K S  p 0 p 0 : 4 photons from the IP Hep-ex/ EPJC in press Time stability BR(K S  p + p – (g))/BR(K S  p 0 p 0 ) R p S =  R p S =  BR(K S  p + p – (g)) = (  )  BR(K S  p 0 p 0 ) = (  )  Most precise values

Roberto Versaci Heavy Quarks and Leptons '06 – München / PLB 636 (2006) E miss – P miss ● Normalized to BR(K S  p + p - ) ● K S  p + p - background rejected using TOF PID ● Signal from fit to E miss – P miss spectrum Allows test of CP, CPT and DS = DQ rule K S  p en e (g) Linear slope of the form factor l + = ( 33.9 ± 4.1 ) x BR(K S  p e n e ) = (7.082  0.092)  10 -4

Roberto Versaci Heavy Quarks and Leptons '06 – München / G (K S  p - e + n e ) - G (K S  p + e - n e ) G (K S  p - e + n e ) + G (K S  p + e - n e ) A S = = (1.5 ± 9.6 ± 2.9) x G S vs G L : test of DS=DQ rule A S vs A L : tests of CP and CPT A S - A L = 4 (Re d + Re x_ ) A S + A L = 4 (Re e - Re y ) 2 Re x + = (G S -G L ) / (G S +G L ) Re x + = (-1.2  3.6)  Re x_ = (-0.8  2.5)  Re y = (0.4  2.5)  BR(K S  p - e + n e ) = (3.528  0.062)  BR(K S  p + e - n e ) = (3.517  0.058)  With full statistics (5x) A S to 3 x PLB 636 (2006) K S  p en e (g)

Roberto Versaci Heavy Quarks and Leptons '06 – München / PLB 619 (2005) ● K L crash and 6 photons ● Kinematic fit ● Reject events with tracks from the IP ● Cuts using 4 vs 6 photons pairing ● Main background source: K S  p 0 p fake clusters ● Normalization to K S  p 0 p 0 CP violation K S  p 0 p 0 p 0 BR(K S  p 0 p 0 p 0 ) < 1.2  % C.L. A(K S  3p 0 ) < % C.L. A(K L  3p 0 ) h 000 =

Roberto Versaci Heavy Quarks and Leptons '06 – München / To be published Phys. Lett. B QM and CPT tests Loss of coherence z ≠ 0  QM Decoherence parameter depends on the basis: z 00, z SL Quantum gravity may result in QM and CPT (effect in K 0 K 0 ) Using quantum interfence in f  K S K L  p + p - p + p - I(t 1,t 2,g)g ~ O(m K 2 /M P ) ≠ 0 I(t 1,t 2,w)w = |w|e iW ≠ 0 I(t1,t2,z) ∝ exp(-G L t 1 -G S t 1 ) + exp(-G S t 1 -G L t 2 ) - 2(1-z) exp(-(G S +G L )(t 1 +t 2 )) / 2cos(DmDt)

Roberto Versaci Heavy Quarks and Leptons '06 – München / No evidence for QM and CPT Re w x10 2 Im w x % CL 95% CL K L regeneration on the beam pipe  Data: 7366 evts QM and CPT tests z SL =   0.007c 2 /dof = 29.7/32 z 00 = (0.10  0.21  0.04)  c 2 /dof = 29.6/32 g = (  0.4)  GeVc 2 /dof = 33/32  w = (  0.9)  c 2 /dof = 29/31  w = (  0.6)  To be published Phys. Lett. B

Roberto Versaci Heavy Quarks and Leptons '06 – München / Bell-Steinberger relation CPT test in the kaons system Assumes the unitarity conservation 2(m L -m S ) G S -G L tan f SW = d parametrize CPT violation d can be used to constrain Dm K0 and DG

Roberto Versaci Heavy Quarks and Leptons '06 – München / CP and CPT tests Using the Bell-Steinberger relation Submitted to JHEP GeV    (e) = (159.6  1.3)   (d) = (0.4  2.1)   GeV < m K0 -m K0 < 6.3  % C.L.

Roberto Versaci Heavy Quarks and Leptons '06 – München / Charged kaons Lifetime Semileptonic decays K ± ® m ± n m (g) Data sample between 200 and 400 pb -1

Roberto Versaci Heavy Quarks and Leptons '06 – München / K ± lifetime Given the tag, look for the decay vertex of the second kaon ● Method #1: fit t * distribution from decay length Measure the kaon decay length taking into account the energy loss:t * = S i DL i / b i g i c ● Method #2: Directly measure decay time (in progress) Use K  p p 0 decay to reconstruct decay time from p 0 cluster time Two methods allow cross check of systematics Preliminary t  = (  stat  syst ) ns

Roberto Versaci Heavy Quarks and Leptons '06 – München / K ± semileptonic decays ● Fit of the charged secondary square mass spectrum m 2 lept ● Mass of charged secondary from TOF measurement ●  0 reconstruction from 2 neutral clusters in EMC ● Separate measurements for each charge and each tag 4 independent normalization samples Preliminary BR(K   p 0 e  n e ) = (5.047   0.039)  BR(K   p 0 m  n m ) = (3.310   0.045)  10 -2

Roberto Versaci Heavy Quarks and Leptons '06 – München / BR (K ± ®m ± n m (g)) PLB 632(2006) ● Fit of the momentum distribution of the charged secondary, p* ● Background subtraction, p 0 in the final state ● Efficiency evaluated directly on data using uncorrelated sample selected using EMC info ● 8 x 10 5 events ● Total accuracy 0.27% BR(K   m  n m (g)) =   0.015

Roberto Versaci Heavy Quarks and Leptons '06 – München / V us summary l' + = (31) l'' + = (3) (Pole model: KLOE, KTeV and NA48 av.) l 0 = (95) (KTeV and ISTRA+ av.) ● f + (0) = 0.961(8) Leutwyler and Roos [Phys. C25, 91, 1984] ● Vud= (27) Marciano and Sirlin [Phys.Rev.Lett ,2006] Slopes From unitarity V US  f + (0)=0.2187(22)

Roberto Versaci Heavy Quarks and Leptons '06 – München / V ud - V us plane |V us /V ud | can be extracted from the ratio: from lattice MILC Coll. PoS LAT2006 Fitting with V ud, V us + unitarity constraint V ud V us (K l3 ) G (K  mn m (g)) |V US | 2 f K G (p  mn m (g)) |V US | 2 f p ∝ fKfpfKfp = 1.208(2)( ) V us / V ud = ( ) V us = ( ) V ud = (27) c 2 /dof = 0.046/2 P(c 2 ) = 0.97 V us = (7) V ud = (16) c 2 /dof = 3.94/1 P(c 2 ) = 0.05 unitarity V us / V ud

Roberto Versaci Heavy Quarks and Leptons '06 – München / What's next? data (~2 fb -1 ) to be analyzed Complete K ± semileptonic and lifetime cPT, CPV, CPTV V US, DS = DQ rule Lepton universality K L  peng K S  gg K S  p + p - e + e - K S  pmn K S  p + p - p 0 K S  e + e - K ±  p ± p 0 K ±  e ± n / K ±  m ± n K ±  p 0 p 0 e ± n On going analyses

Roberto Versaci Heavy Quarks and Leptons '06 – München / Spare slides

Roberto Versaci Heavy Quarks and Leptons '06 – München / h physics F  h' g / h gh-h' mixing angle h  p 0 g g cPT test h mass h  p + p - p 0, p 0 p 0 p 0 m u -m d Dalitz plots h  ggg, p + p - forbidden C, P, CP h  p + p - e + e - CP

Roberto Versaci Heavy Quarks and Leptons '06 – München / K L lifetime PLB 626 (2005) 100M K L  p 0 p 0 p 0 events ● Require ≥ 3 g s ● e(L K ) ~99%, uniform in L ● Background ~1.3% Use K L  p + p - p 0 to determine ● Calorimeter timescale ● Photon-vertex efficiency ● Resolution: s L (gg) ~ 2 cm Direct measurement: Average with result from K L BRs: t L = (50.84  0.23 ) ns t L = (50.92  0.17  0.25 ) ns

Roberto Versaci Heavy Quarks and Leptons '06 – München / K L selection ● 328 pb -1 split in 14 samples ● Tag given by K S  p + p - e Tag ~63% ● K L kinematic from K S ● Best separation using P miss – E miss ● K e3 K m3 separation using TOF & energy deposit in EMC ● 2g invariant mass and timing P miss – E miss

Roberto Versaci Heavy Quarks and Leptons '06 – München / K L  p + p – (g) h + - = e + e' ≈ e | h + - | =  ((G(K  p + p - ))/(G(K  p + p - ))) | h + - | has been determined using: t KL from KLOE t KS from PDG'04 BR(K S  p + p - ) from KLOE e has been determined using: Re(e'/e) PDG'04 arg e' = arg e |e| = (2.216  0.013)  | h + - | = (2.219  0.013)  10 -3

Roberto Versaci Heavy Quarks and Leptons '06 – München / PLB 636 (2006) E miss – P miss ● Normalized to BR(K S  p + p - ) ● K S  p + p - background rejected using TOF PID ● Signal from fit to E miss – P miss spectrum Allows test of CP, CPT and DS = DQ rule K S  p en e (g)

Roberto Versaci Heavy Quarks and Leptons '06 – München / PLB 636 (2006) Consistent with DS = DQ rule Charge asymmetry A S = (1.5 ± 9.6 ± 2.9) x 10-3 With full statistics (5x) KLOE will measure A S to 3 x Linear slope of the form factor l + = ( 33.9 ± 4.1 ) x BR(K S  p - e + n e ) = (3.528  0.062)  BR(K S  p + e - n e ) = (3.517  0.058)  BR(K S  p e n e ) = (7.082  0.092)  K S  p en e (g)

Roberto Versaci Heavy Quarks and Leptons '06 – München / G (K S  p - e + n e ) - G (K S  p + e - n e ) A S = Comparison of charge asymeetries A S and A L allows tests of CP and CPT Comparison of decay widths allows test of DS=DQ rule A S - A L = 4 (Re d + Re x_ ) A S + A L = 4 (Re e - Re y ) 2 Re x + = (G S -G L ) / (G S +G L ) Re x + = (-1.2  3.6)  Re x_ = (-0.8  2.5)  Re y = (0.4  2.5)  K S  p en e (g)

Roberto Versaci Heavy Quarks and Leptons '06 – München / K ± lifetime Discrepancy between in-flight and at-rest measurements Discrepancy among different stoppers in at-rest measurements Confirmation is needed

Roberto Versaci Heavy Quarks and Leptons '06 – München / independent normalization samples (2 tag x 2 charges) 410 pb -1 self-triggering tags from 2001 and 2002 data Fit of the charged secondary square mass spectrum m 2 lept K     and K      rejected cutting on p*(m  ) Efficiency evaluated from MC and corrected for Data/MC ratio K ± semileptonic decays

Roberto Versaci Heavy Quarks and Leptons '06 – München /    e+e+e+e+   Two tracks vertex in the FV: 40 cm <  < 150 cm Track of charged secondary extrapolated to EMC Two body decays cut: p*(m  ) < 195 MeV/c  0 reconstruction: 2 neutral clusters in EMC with TOF matching the kaon decay vertex Mass of charged secondary from TOF measurement K ± l3 signal selection

Roberto Versaci Heavy Quarks and Leptons '06 – München /         with a   undergoing a Dalitz decay, or with a wrong cluster associated to    give a m l 2 under the Ke3 peak  cut requiring (E miss – P miss ) < 90 MeV       with early    , give m l 2 under the K  3 peak  rejected using the missing momentum of the secondary track in the pion rest frame (P* sec < 90 MeV) K  0  0 K  0 K nucl.int. K3K3 Ke 3 K ± l3 background (I)

Roberto Versaci Heavy Quarks and Leptons '06 – München / The residual background is ≈ 1.5% of the selected K ± l3 sample. It has m lept 2 ≈ m  2       K nucl.int.     The cuts reject ≈ 96% of the background events The efficiency on the signal is ≈ 50% for both K e3 and K  3 K ± l3 background (II)

Roberto Versaci Heavy Quarks and Leptons '06 – München / V us from semileptonic decays

Roberto Versaci Heavy Quarks and Leptons '06 – München / 26 41