Recent results of KLOE at DA NE nb
Recent results of KLOE at DA NE [nb] V. Patera Rome I University & Laboratori Nazionali di Frascati (INFN) s [Me. V] V. Patera CERN seminar 28 March 2006 1
DA NE & KLOE : the origin Daphne DA NE (Greek a i , English laurel, Italian alloro) daughter of the river god Peneios and Gaea (goddess of the earth) flew the courting of Apoll and was metamorphosed into laurel by her mother; later on the name of this plant was attributed to Apoll not to be confused with Daphnis – son of Hermes (Mercurius) and a Sicilian nymph Chloe KLOE – the greening, is a surname of Demeter (Ceres) Daphnis and Chloe – couple of lovers in the hononymous novel of Logos (~300 a. C. ) – made famous by Ravel symphonic poem V. Patera CERN seminar 28 March 2006
Outline Physics @ peak DA NE, the frascati factory The KLOE detector KLOE recent results: Kaon physics (mostly) Non Kaon physics Future of KLOE & DA NE Summary and conclusions Recent results → 2005 -2006 V. Patera CERN seminar 28 March 2006 3
Physics at a -factory (I) Not only KAON physics A factory is a collider e+erunning at s = M = 1. 02 Ge. V 0 - 1 - 0+ (1020) BR 83% KK ' BR 1. 3% BR 15% Vus , Medium-Rare KS, L decays, CPT with Ks , KL charge asymmetries, Quantum Interferometry, But also: hadronic cross section , radiative decays. “Natural” luminosity unit: fb-1 a 0(980) f 0(980) decay Produced ev/fb-1 K+ K- 1. 5 x 109 KLKS 1. 0 x 109 5 x 107 ’ 2 x 105 V. Patera CERN seminar 28 March 2006
Physics at the -factory (II) Extensively study all the possible decay channels with a multipurpose detector Kaon physics BR( K +K ) = 49. 2% BR( K 0 K 0) = 33. 8% KSKL and K+K- pairs are produced in a pure quantum state (JPC=1 --) : #unique feature is the production of pure and quasi monochromatic KS, KL, K+ and K- beams decay ~at rest. Detection of a KS (KL) guarantees the presence of a KL(KS) with known momentum and direction (the same for K +K ) # precision measurement of absolute BR’s #interference measurements in KS KL system V. Patera CERN seminar 28 March 2006 5
Physics at the -factory (III) Non-kaon physics Radiative decays ( ) M to probe the quark structure of the meson M ’ mixing angle a 0 f 0 Hadronic cross-section measurement using the Initial State Radiation to vary the energy: e+ e For theoretical estimate of the hadronic contribution (a hadr) to the anomalous magnetic moment of the muon (a ) down to the threshold energy for production V. Patera CERN seminar 28 March 2006 ISR s’ 6
Outline Physics @ peak DA NE, the frascati factory The KLOE detector KLOE recent results: Kaon physics (mostly) Non Kaon physics Future of KLOE & DA NE Summary and conclusions V. Patera CERN seminar 28 March 2006 7
DA NE: the Frascati -factory • e e collider @ s = M = 1019. 4 Me. V • 2 interaction regions (KLOE – DEAR/FINUDA) • Separate e , e rings to minimize beam-beam interactions • Crossing angle: 12. 5 mrad ( px 12. 5 Me. V ) V. Patera CERN seminar 28 March 2006
DA NE: the Frascati -factory • 105+105 bunches • 2. 7 ns bunch spacing • I-peak ~ 2. 4 A • I+peak ~ 1. 5 A • Injection during data taking V. Patera CERN seminar 28 March 2006
DA NE 24 h Performance (Dec. 05) 1. 2 e-32 ee+ 2 A 1 A 8 pb-1 V. Patera CERN seminar 28 March 2006 10
s (Me. V) DA NE: energy stability s monitored to within 70 ke. V 2004 Some variations in 2004 Stable (1019. 3 -1019. 6) in 2005 s (Me. V) Run number 2005 IP position, spot size and s monitored on line by bhabha and KK events V. Patera CERN seminar 28 March Run 2006 number 11
KLOE@DA NE: the data sample Data taking finished march 2006 • Lpeak= 1. 3 × 1032 cm s • Integrated L 2. 5 fb-1 • 200 pb-1 off-peak 2004 734 pb-1 2005 1256 pb-1 analysis ongoing 2001 170 pb-1 2002 280 pb-1 Analysis nearly complete V. Patera CERN seminar 28 March 2006
Outline Physics @ peak DA NE, the frascati factory The KLOE detector KLOE recent results: Kaon physics (mostly) Non Kaon physics Future of KLOE & DA NE Summary and conclusions V. Patera CERN seminar 28 March 2006 13
KLOE experiment The KLOE design was driven by the measurement of direct CP through the double ratio: R = (KL + ) (KS 0 0) / (KS + ) (KL 0 0) Be beam pipe (spherical, 10 cm , 0. 5 mm thick) + instrumented permanent magnet quadrupoles (32 PMT’s) Drift chamber (4 m 3. 75 m, CF frame) Gas mixture: 90% He + 10% C 4 H 10 12582 stereo–stereo sense wires almost squared cells Electromagnetic calorimeter lead/scintillating fibers (1 mm ), 15 X 0 4880 PMT’s 98% solid angle coverage Superconducting coil (B = 0. 52 T) V. Patera CERN seminar 28 March 2006
The KLOE Calorimeter: • Pb-scintillating fibers matrix: <ρ> ~ 5 g/cm 3, <X 0>~ 1. 6 cm • 4880 PMTs • 98% hermetic coverage Lead σ(E)/E = 5. 7%/ E(Ge. V) σ(t) = 54 ps/ E(Ge. V) 50 ps ε 95% for 20 Me. V photons vtx( ) ~ 1. 5 cm ( from KL ) V. Patera CERN seminar 28 March 2006 9
The KLOE Drift Chamber: • 90% He, 10% i. C 4 H 10 ( X 0=900 m ) • 12582 stereo sense wires • structure in C-Fibre (<0. 1 X 0) • Non saturated drift velocity • 2 x 2 (inner) & 3 x 3 (outer) cm 2 squared cell size Drift Chamber p/p = 0. 4 % (tracks with > 45°) xhit = 150 m (xy), 2 mm (z) xvertex ~ 1 mm (M ) ~1 Me. V (from KS→ ) V. Patera CERN seminar 28 March 2006
Outline Physics @ peak DA NE, the frascati factory The KLOE detector KLOE recent results: Kaon physics (mostly) Non Kaon physics Future of KLOE & DA NE Summary and conclusions V. Patera CERN seminar 28 March 2006 17
K physics at KLOE - tagging The decay at rest provides monochromatic and pure beam of kaons pure JPC = 1 state K S, K K L, K decay mode BR K K 49. 1% KSKL 34. 1% Tagging: observation of KS, L signals presence of KL, S ; K+ signals K Clean , normalized K+, K-, KL and KS beams (KS unique!!) absolute branching ratio measurement: BR=(Nsig/Ntag)(1/ sig) Kaon momentum is measured with 1 Me. V resolution (e. g. p(KL) = p( )- p(KS)) K +K = 0. 245 p* = 127 Me. V/c ±= 95 cm K LK S = 0. 22 p* = 110 Me. V/c S = 6 mm; L = 3. 4 m V. Patera CERN seminar 28 March 2006 18
Neutral Kaons KS semileptonic decays KS → decay KL dominant BR’s KL lifetime KLe 3 form factor slopes KL → - + and KL, KS and Bell-Steinberger KL, KS Quantun Interferometry V. Patera CERN seminar 28 March 2006 19
Tagging of KS KLbeams KL tagged by KS vertex at IP KS tagged by KL interaction in Em. C KL “crash” =0. 22 (TOF) K S KL 2 ~ 70% (mainly geometrical) KL angular resolution: ~ 1° KL momentum resolution: ~ 1 Me. V K S e ~ 30% (largely geometrical) KS angular resolution: ~ 1° (0. 3 in ) KS momentum resolution: ~ 1 Me. V V. Patera CERN seminar 28 March 2006 20
Analysis of KS → e decays Event selection (410 pb-1 ) Fit distributions of 5 variables in data with various MC sources including e and processes • KS tagged by KL crash • Kinematic cuts to reject background from KS → • Track-cluster association • e/ ID from TOF • Identify the charge of final state Obtain number of signal events from a constrained likelihood e fit of multiple data distributions Events/Me. V e • 2 tracks from IP to EMC 700 600 500 400 300 200 100 Data MC fit e bad other 0 Normalize using KS 0 50 100 50 events in same Emiss( e) pmiss (Me. V) data set V. Patera CERN seminar 28 March 2006 21
KS e decay – Results Ac ce pte d BR(KS e+ ) = (3. 529 0. 057 0. 027) 10 -4 by PL B BR(KS e- ) = (3. 518 0. 051 0. 029) 10 -4 BR(KS e ) = (7. 048 0. 076 stat 0. 050 syst) 10 -4 BR( e ) [KLOE ’ 02, Phys. Lett. B 535, 17 pb 1]: (6. 91 0. 34 stat 0. 15 syst) 10 -4 Charge asymmetry A= K→ K→ AS=AL AS A L if CPT and S= Q signals CPT in mixing and/or decay with S Q AS-AL=4 Re( ) if CPT holds in decays with S Q ASe = (1. 5 9. 6 2. 9) 10 -3 Linear form factor slope With 2. 5 fb 1: AS 3 10 3 2 Re + = (33. 8 4. 1) 10 -3 In good agreement with linear fit from KL semileptonic form factor [ ( 28. 6 0. 6)× 10 V. Patera CERN seminar 28 March 2006 22
KS e : CPT test Sensitivity to CPT violating effects through charge asymmetry AS, L = (KS, L -e+ ) (KS, L +e- ) AS = 2(Re Re Re y Re x ) AS A L 0 violates CPT S Q AL = 2(Re. CP Re CPT iny Re and CPT mixing decay x ) 1 M 11 M 22 i 2 m. S m. L i S L AL = (3. 322 0. 058 0. 047) 10 -3 , KTe. V 2002 V. Patera CERN seminar 28 March 2006 23
KS → e : results Test of S = Q rule Ac ce pte d BR(KLe 3) (KS) = 89. 58 0. 06 ps PDG 0. 40 (KL) = 51. 01 0. 20 ns PDG + KLOE ’ 05 (avg. ) 0. 39 Test of S = Q rule by PL B KTe. V ’ 04 KLOE ’ 05 KLOE KS assuming S = Q PDG ’ 04 Test of CPT and S Q: (x+) = ( 0. 4 3. 1 1. 8) × 10 (x ) = ( 0. 2 2. 4 0. 7) × 10 Factor 2 improvement w. r. t. current most precise measurement Factor 5 improvement w. r. t. current most precise measurement (CPLEAR, ) (KS) (KL) BR(KL→ e ) (CPLEAR, ) PDG + KLOE ’ 05 (avg. ) KLOE V. Patera CERN seminar 28 March 2006 AL ( ) KTe. V CPLEAR 24
KS : first observation • Measurement never done before • More difficult than KSe 3: 2002 Data KS + + 1) Lower BR: expect 2) Background events from KS : same PIDs of the signal • Event counting from the fit to Emiss( ) Pmiss distribution: 3% stat error -40 • Efficiency estimate from KL early decays and from MC + data control samples. -20 V. Patera CERN seminar 28 March 2006 0 20 40 Emiss Pmiss (Me. V) 25
KS 0 0 0 – test of CP and CPT KS 3 0 is purely CP violating If CPT conserved, S = L | ’ 000|2 BRSM(KS 3 0) = 1. 9 × 10 9 • MC 3 (BR 10 5) • MC 2 Best previous result from direct search: BR < 1. 4 × 10 5 90% CL [SND ’ 99] BR< 7. 4 10 7 [interference, NA 48, ‘ 04] Signature ( presel ~ 14%): KL crash + 6 ’s, no tracks from IP Background rejection: KS + 2 split/accidental clusters Define signal box in 23 vs. 22 plane: 3 cluster pairs with best 0 mass estimates 2 best cluster pairs - 0 masses, E(KS), p(KS), angle between 0’s V. Patera CERN seminar 28 March 2006
KS 0 0 0 (II) 350 pb-1 MC Nbkg(MC) = 3. 13 ± 0. 82 ± 0. 37 Eff. Stat. = Nobs = 2 5. 3 data KLOE 450 pb 1 ’ 01+’ 02 data BR < 1. 2 × 10 7 90% CL 450 pb 1 ’ 01+’ 02 data Prospects for 2. 5 fb 1: • 6. 5 increase in statistics (L efficiency) • 1. 5 decrease in background Potential to reduce limit ~10 PLB 619 (2005) V. Patera CERN seminar 28 March 2006
Dominant KL branching ratios Absolute BR measurements to 0. 5 -1% from 328 pb-1 data sample KL tagged by KS : • 13 106 for the measurement • 4 106 used to evaluate efficiencies BR’s to e , , and + - 0: • KL vertex reconstructed in DC • PID using decay kinematics • Fit with MC spectra including radiative processes and optimized Em. C response to / /KL BR to 0 0 0: • Photon vertex reconstructed by TOF using Em. C (3 clusters) • rec = 99%, background < 1% Lesser of pmiss Emiss in or hyp. (Me. V) V. Patera CERN seminar 28 March 2006 28
Dominant KL BR’s and KL lifetime Using the constraint BR(KL) = 1 we get: L direct measurement from KL 400 pb 1) • Require 3 ’s • (LK) ~ 99%, uniform in L • L( ) ~ 2. 5 cm • Background ~ 1. 3% Use KL π+π-π0 for: • Em. C time scale • Photon vertex efficiency x 102 Events/0. 3 ns [PLB 632 (2006)] BR(KL e ) = 0. 4007 0. 0006 stat 0. 0014 syst BR(KL ) = 0. 2698 0. 0006 stat 0. 0014 syst Lifetime indirect measurement: BR(KL 3 ) = 0. 1997 0. 0005 stat 0. 0019 syst = 50. 72 0. 17 0. 33 ns L BR(KL ) = 0. 1263 0. 0005 stat 0. 0011 syst Lifetime direct measurement [PLB 626 (2005)] : L = 50. 92 0. 17 0. 25 ns KL lifetime, KLOE average : L = 50. 84 0. 23 ns V. Patera CERN seminar 28 March 2006 PK = 110 Me. V Excellent lever arm for lifetime measurement 6 - 24. 8 ns 40 -165 cm 0. 37 L L/ c (ns) Vosburg, ’ 72: L = 51. 54 ± 0. 44 ns 29
KLe 3 form factor slopes Ac ce pte d • 328 pb 1, 2 106 Ke 3 decays by PL • Kinematic cuts + TOF PID to reduce background ( ~ 0. 7% final contamination ) B • Separate measurement for each charge state (e , e ) to check systematics • t measured from and KL momenta: t/m 2 0. 3 Linear fit 103 (*) ISTRA+ m /m 0 correction 2/dof e 28. 7 0. 7 156/181 e 28. 5 0. 6 174/181 All 28. 6 0. 5 330/363 = (28. 6 0. 5 0. 4) 10 3 Quadratic fit 103 2/dof e 24. 6 2. 1 1. 9 1. 0 152/180 e 26. 4 2. 1 1. 0 173/180 All 25. 5 1. 5 1. 4 0. 7 325/362 = (25. 5 1. 0) 10 3 = ( 1. 4 0. 7 0. 4) 10 3 Correlation: ( , ) = 0. 95 Pole model MV = 870(7) Me. V Phase space integral Pole model versus Quadratic parameterization: • KLOE: 0. 5 per mil difference • KTe. V: 6 per mil difference. V. Patera CERN seminar 28 March 2006 30
BR KL Decay CP violating Related to K KL beam tagged by KS → 328 pb-1 ’ 01+’ 02 data Selection • KL vertex reconstructed in DC • PID using decays kinematics • Fit with MC spectra including radiative processes Normalize using KL events BR(KL )= (1. 963 0. 012 0. 017) 10 -3 V. Patera CERN seminar 28 March 2006 Su bm itt ed to PL B
• KLOE in agreement with KTe. V [PRD 70 (2004), 092006] • BR=(1. 975 0. 012) confirm the discrepancy (4 standard deviations) with PDG 04 BR(KL ) 10 -3 BR KL and l l PDG 2004 KTe. V KLOE preliminary Using BR(KS ) and L agreement with prediction from Unitarity Triangle (1. 5 ) from KLOE and S from PDG 04 | = (2. 216 0. 013) 10 -3 | | PDG 04 = (2. 280 0. 013) 10 -3 V. Patera CERN seminar 28 March 2006
CPT test: Bell-Steinberger relation Measurements of KS KL observables can be used for the CPT test from unitarity : 1 (1 + i tan SW) [Re i Im ] A*(KS f ) A(KL f ) f f f S kl 3 S L B(KLl 3) Re Re y i( Im Im x ) S L B(KLl 3) (AS+AL)/4 i( Im Im x ) KS S L KL 00 KS S L KL KS f = A(KL →f)/A(KS →f) V. Patera CERN seminar 28 March 2006 33
CPT test: inputs to the Bell-Steinberger relation KS S 0. 08958 ± 0. 00006 ns KL L= 50. 84 ± 0. 23 ns KL l A KS L A KL S KL KS KL SW = (0. 759± 0. 001) =0. 757 ± 0. 012 = 0. 763 ± 0. 014 Im x+ = (0. 8 ± 0. 7) 10 -2 KLOE measurements Im x from a combined fit of KLOE + CPLEAR data V. Patera CERN seminar 28 March 2006 34
CPT and Bell-Steinberger: result Im Re KLOE preliminary: Re Im CPLEAR: Re Im - Uncertainty on Im is now dominated by and - Semileptonic sector contributes by ~ 10% V. Patera CERN seminar 28 March 2006 35
t=t 1 -t 2 t 1 t 2 m from here I( t) (a. u) Kaon interferometry: KSKL Perfect vertex reolution no simultaneous decays ( t=0) in the same final state due to the destructive quantum interference t/ S V. Patera CERN seminar 28 March 2006
KSKL • Analysed data: L=380 pb • Fit including t resolution and efficiency effects + regeneration • S, L fixed from PDG KL regeneration on beam pipe KLOE PRELIMINARY m = (5. 34 0. 34) 109 s 1 At 2. 5 fb-1 m 0. 14 109 s 1 PDG ’ 04: (5. 290 0. 016) 10 s 1 Best (Ktev’ 03)(5. 288 0. 043) 10 s 1 V. Patera CERN seminar 28 March 2006 Data Fit result
KSKL : test of quantum coherence • Fit including t resolution and efficiency effects + regeneration • S, L m fixed from PDG Decoherence parameter: KLOE preliminary result: From CPLEAR data, Bertlmann et al. (PR D 60 (1999) 114032) obtain: with 2. 5 fb-1 : as CP viol. O( > high sensitivity to z V. Patera CERN seminar 28 March 2006
Charged Kaons K ± lifetime BR(K+ 2 ) K± semileptonic decays V. Patera CERN seminar 28 March 2006 39
Tagging K+ KMeasurement of absolute BR’s: K beam tagged from K Two-body decays identified as peaks in the momentum spectrum of secondary tracks in the kaon rest frame: 6 x 108 tags/fb-1 Given the tag a dedicated reconstruction of K tracks is performed, correcting for d. E/dx losses of charged kaons in the DC 102 Ev/0. 5 Me. V Kinem. ID Data 3000 — fit: – – 2000 + 1000 180 200 220 240 p* (Me. V) + K + + K – – 0 V. Patera CERN seminar 28 March 2006 40
Measurement of BR(K ( )) MC includes Signal selection radiative process • Tag from K- -. • 175 pb-1: 1/3 used for signal selection, 2/3 used as efficiency sample • Subtraction of 0 identified background. • Count events in (225, 400) Me. V window of the momentum distribution in K rest frame ( hypothesis) region • Selection efficiency measured on data • Radiated acceptance measured on MC BR(K+ + ( )) = 0. 6366 0. 0009 stat. 0. 0015 syst. [PLB 632 (2006)] • (K ( ))/ ( ( )) |Vus|2/|Vud|2 f. K 2/f 2 • From lattice calculations: f. K /f =1. 198(3)(+16 5) (MILC Coll. Po. S (LAT 2005) 025, 2005) P* [Me. V] |Vus| / |Vud| =0. 2294 0. 0026 V. Patera CERN seminar 28 March 2006 41
Measurement of the K lifetime • Tag events with K 2 decay • Kaon decay vertex in the fiducial volume • Measure from PDG not in agreement PDG = (12. 385± 0. 024)ns 16 -30 ns 200 pb-1 K (ns) KLO E pr elim Measure the kaon decay length taking into account the energy loss: K = i Li/( i ic) • Tracking efficiency and resolution functions measured on data by means of neutral vertex identification. • Fit of the K distribution. = 12. 367 0. 044 Stat 0. 065 Syst ns inar y V. Patera CERN seminar 28 March 2006 42
Measurement of BR(K ℓ 3) 4 independent-tag samples: K+ 2, K 2, and K 2 keep under control the systematic effects due to the tag selection Kinematical cuts to reject non-semileptonic decays, residual background is about 1. 5% of the selected K l 3 sample Constrained likelihood fit of m 2 data distributions from To. F measurements count the number of signal events Selection efficiency from MC and correct for Data/MC differences. Ev/(14 Me. V)2 Perform the BR measurement on each tag sample, separately normalizing to tag counts in the same data set, and average accounting for correlations: K e 3 K nuc. int K 0 0 KLOE p relimina r y BR(K e 3) = (5. 047 0. 019 Stat 0. 039 Syst-Stat 0. 004 Sys. Tag)× 10 -2 BR(K 3) = (3. 310 0. 016 Stat 0. 045 Syst-Stat 0. 003 Sys. Tag)× 10 -2 V. Patera CERN seminar 28 March 2006 43
All Kaons together! Test of CKM unitarity: the first row V. Patera CERN seminar 28 March 2006 44
Unitarity test of CKM matrix – Vus & Vus / Vud • Most precise test of unitarity possible at present comes from 1 st row: |Vud|2 + |Vus|2 + |Vub|2 ~ |Vud|2 + |Vus|2 1 – Can test if = 0 at 10 -3 level: from super-allowed nuclear -decays: 2|Vud| Vud = 0. 0005 from semileptonic kaon decays: 2|Vus| Vus = 0. 0009 • Extract |Vus| from Kl 3 decays. EM effects must be included: (K ℓ ) |Vus f+K 0 -(0) |2 I( t) SEW(1 + + SU(2) ) |Vus| t) f+K 0 -(0) Relative uncertainty: = 0. 5 t) |Vus| f+K 0 -(0) • Extract |Vus|/ |Vud| from (K ( ))/ ( ( )) ratio. Dominated by theoretical uncertainity on the f. K/f evaluation from lattice QCD • KLOE can measure almost all experimental inputs for neutral and charged kaons: branching ratios, lifetimes, and form factors (but S). V. Patera CERN seminar 28 March 2006 45
Vus from KLOE results (BR’s and L) KL e 3 BR 0. 4007(15) Slopes KL 3 KS e 3 K 3 0. 2698(15) 7. 046(91)× 10 -4 0. 05047(46) 0. 03310(40) 50. 84(23) ns 89. 58(6) ps 12. 384(24) ns (Pole model: KLOE, KTe. V, and NA 48 ave. ) (KTe. V and Istra+ ave. ) From unitarity • f+(0)=0. 961(8) Leutwyler and Roos Z. [Phys. C 25, 91, 1984] • Vud=0. 97377(27) Marciano and Sirlin [Phys. Rev. Lett. 96 032002, 2006] 2/dof = 1. 9/4 V. Patera CERN seminar 28 March 2006 Vus×f+(0) = 0. 2187(22) 46
Vus around the world and Unitarity Vus f+(0) PDG 04 plot: F. Mescia courtesy PDG 04 • L = 50. 99(20) ns, average KLOE-PDG • Including all new measurements for semileptonic kaon decays (KTe. V, NA 48, E 865, and KLOE) From unitarity • f+(0)=0. 961(8) Leutwyler and Roos [Z. Phys. C 25, 91, 1984] • <Vus×f+(0)>WORLD AV. = 0. 2164(4) V. Patera CERN seminar 28 March 2006 Vud=0. 97377(27) Marciano and Sirlin [Phys. Rev. Lett. 96 032002, 2006] Vus×f+(0) = 0. 2187(22) 47
The Vus Vud plane Inputs: Vus = 0. 2254 0. 0020 Kl 3 KLOE, using f+(0)=0. 961(8) Vud = 0. 97377 0. 00027 Marciano and Sirlin Phys. Rev. Lett. 96 032002, 2006 Vus/Vud = 0. 2294 0. 0026 ty tari uni K 2 KLOE (K ( ))/ ( ( )) |Vus|2/|Vud|2 f. K 2/f 2 Fit results, P( 2) = 0. 66: Vus = 0. 2246 0. 0016 Vud = 0. 97377 0. 00027 Fit result assuming unitarity, P( 2) = 0. 23: Vus = 0. 2264 0. 0009 V. Patera CERN seminar 28 March 2006 48
Non Kaons physics (my personal selection) mass (e+e → ) off peak physics @ 1 Ge. V V. Patera CERN seminar 28 March 2006 49
measurement @ KLOE Large discrepancy between the two most precise measurements GEM: M = (547. 311 ± 0. 028 ± 0. 032) Me. V/c 2 NA 48: M = (547. 843 ± 0. 030 ± 0. 041) Me. V/c 2 PLB 619 (2005) 281 PLB 533 (2002) 196 Ø measurement method measurement: E 3 cross checking: E 1 E 2 After the kinematic fit (p, Etot, cluster times) the mass measurement is almost independent from the energy of the clusters, it is dominated by the cluster positions. The momentum and the vertex position are precisely determined from Bhabha scattering at large angle e+e- → e+e. Absolute scale buy line shape and mass V. Patera CERN seminar 28 March 2006
measurement @ KLOE • Kinematic fit applied on → events and 0 selected by looking at different Dalitz plot regions 2/ndf = 304/257 0 0 <m > = ( 134. 956 0. 018 ) Me. V = ( 1. 66 0. 005 ) Me. V M (Me. V) 2/ndf = 146/161 E 1<E 2<E 3 <m > = ( 547. 708 0. 014 ) Me. V M (Me. V) = ( 2. 143 0. 012 ) Me. V V. Patera CERN seminar 28 March 2006 M (Me. V) 51
M (Me. V) Data set divided in 8 periods M (Me. V) measurement @ KLOE 547. 95 547. 90 NA 48 547. 85 547. 80 M( 0) = ( 134990 6 stat 30 syst ) ke. V M( 0)PDG = ( 134976. 6 0. 6 ) ke. V 547. 75 547. 70 M( ) = ( 547822 5 stat 69 syst ) ke. V ary n i m i l e r KLOE p Systematics mainly from √s and vertex position EMC linearity in progress NA 48 compatibility: 0. 24 V. Patera CERN seminar 28 March 2006 52
μ and (e+e → ) @ KLOE Dispersion integral relates a had(vac-pol) to s(e+e- hadrons) Process e+e- + - @ s < 1 Ge. V contributes as much as 66% to a had So far, estimates of a had from: 1) measuring (e+e ) vs s at an e+e- collider, varying the beam energy 2) using the spectral function from (LEP, CESR data) V. Patera CERN seminar 28 March 2006
(e+e → ) @ KLOE At the mass it is possible to measure e+e with high accuracy: (s’ = s – 2 E s) Exploit ISR to extract (e+e + ) for s´ from 2 m s Luminosity from e+e ( ) counts, 55 < e < 125 , at 0. 5% (th) 0. 3%(exp) Radiator function H(M ), defined as: M 2 d M d. M FSR M M with inclusion of radiative effects, as FSR, from QED MC calculation (PHOKHARA, Karlsuhe Theory Group, Kühn et al. ) V. Patera CERN seminar 28 March 2006 54
(e+e → ) : data samples for events Photons at small angles ( < 15 o or > 165° ) Photon NOT DETECTED High Statistics for ISR Photons Low relative contribution of FSR <0. 5% in entire M – range Small amount of other background Photons at large angle ( 50 o < < 130° ) Photon detection required High amount of FSR and background Allows measurement at threshold Allows measurement of charge asymmetry Test of FSR V. Patera CERN seminar 28 March 2006 55
(e+e → ) : small angle results ( e+e- ) nb KLOE 1200 2001 Data 1000 140 pb-1 800 600 CMD-2 (‘ 04) [0. 37 -0. 93 Ge. V 2] 1400 2 contribution to a hadr CMD-2 EPS (‘ 05) preliminary SND (‘ 05), KLOE (‘ 05) 40 0 a [10 -10 ] 200 0. 3 0. 4 0. 5 0. 6 0. 7 0. 8 M 2 0. 9 (Ge. V 2) Phys. Lett. B 606 (2005) 12 • fair agreement btw all 4 data sets CMD-2 and KLOE agree within 0. 5 • disagreement btw KLOE and SND ca. 1. 5 V. Patera CERN seminar 28 March 2006 56
(e+e → ) : improvement at small angle The goals for the analysis of 2002 data: considerable reduction of errors Changes of online and offline reconstruction New version of BABAYAGA with full NLO d. N/d. M 2 (events/Ge. V 2) Normalisation to Muons 2002 Data Acceptance Trigger * Tracking Vertex Reconstruction Filter * Particle ID Trackmass Cut Background Unfolding Effects Total experimental error Luminosity * Vacuum Polarization FSR Corrections Radiator Function Total theoretical error *Goal : Error < 1% M 2 (Ge. V 2) V. Patera CERN seminar 28 March 2006 0. 3% <0. 3% << 0. 6% 0. 1% 0. 2% 0. 3% 0. 2% 0. 9% <<0. 6% 0. 2% 0. 3% 0. 5% 0. 9%
(e+e → ) : large angle PRO & CONTRA pr MC< the threshold region is accessible photon tagging is possible (4 -momentum constraints) lower signal statistics large FSR contributions large background irreducible bkg. from decays eli na ry 50 o< <130 o L = 240 pb-1 By means of dedicated selection cuts it is possible to fight the dominant background Analysis in very advanced state Threshold region non-trivial due to irreducible FSR-effects, which have to be cut from MC using phenomenol. Models (interference effects unknown) mi M 2 (Ge. V 2) FSR & f 0 V. Patera CERN seminar 28 March 2006 & f
(e+e → ) : Forward-backward asymmetry : + - system: A(ISR) C-odd while A(FSR) & A(scalar) C-even asymmetry in the variable: Phys. Lett. B 634 (06), 148 90 o MC • data MC: ISR+FSR+f 0(KL) Pion polar angle [o] Using the f 0 amplitude from Kaon Loop model, good agreement data-MC* both around the f 0 mass and at low masses. * G. Pancheri, O. Shekhovtsova, M (Me. V) V. Patera CERN seminar 28 March 2006 G. Venanzoni, hep-ph/0506332 59
@ large angle: looking for f 0 The f 0 signal is a deviation of M spectrum from the expected ISR + FSR shape. Scalar amplitude from models: 1. Kaon-loop KL (Achasov-Ivanchenko, NPB 315 1989): for each scalar meson S there are three free parameters of the fit: g. S , g. SKK, MS K 2. Events/1. 2 Me. V 676000 events g KK S g. SKK g. SPP No-Structure NS (by. KG. Isidori and L. Maiani ): a modified BW + a polynomial continuum: g S , g. SKK, MS + pol. cont. parameters e+ e- V S g. VS g. S V. Patera CERN seminar 28 March 2006 M( ) (Me. V) f 0(980) region M( ) (Me. V)
Fit to the m( ) spectrum: (491 bins, 1. 2 Me. V wide, m( ) = 420 to 1009 Me. V) KL fit NS fit Fit : ISR + FSR + + scalar ± interf(SCAL+ FSR) Kaon-Loop and No-Structure fits: f 0 signal Good description in both cases of signal and background “negative” interference; The introduction of a (600) doesn’t improve the fit. [PLB 634 (2006) 148] V. Patera CERN seminar 28 March 2006 f 0 signal
s ( Me. V ) Off resonance run @ 1 Ge. V s = 1030 s = 1023 s = 1018 s = 1010 s = 1000 • background-free Radiative Return 200 pb-1 allow to be statistically competitive with VEPP-2000 at threshold • a -scan allows to study the modeldependence in desciption of f 0(980) • background-free - program • KLOE Integrated 200 pb-1 at s = 1. 00 Ge. V • In addition has been performed a -scan of 4 points, 10 pb-1 each First look into off-peak-data very promising. . . ! - Large photon angle acceptance cuts - PID: both tracks identified as pions Number of Events / Me. V Run-Nr. 10 pb-1 ONPEAK OFFPEAK V. Patera CERN seminar 28 March 2006 Trackmass [Me. V]
KLOE physics papers published to date KS KL K+ + 0 0 KS 0 0 0 PLB 535, 37 (02) PLB 538, 21 (02) PLB 566, 61 (03) PLB 597, 49 (04) PLB 619, 61 (05) 0 0 0 ' + 0 + l + l + PLB 536, 203 (02) PLB 537, 21 (02) PLB 541, 45 (02) PLB 561, 55 (03) PLB 606, 12 (05) PLB 608, 199 (05) PLB 634, 148 (06) KL lifetime PLB 626, 15 (05) KL main PLB 632, 43 (06) K+ + ( ) PLB 632, 76 (06) + V. Patera CERN seminar 28 March 2006 PLB 591, 49 (04) PLB 606, 12 (05)
Outline Physics @ peak DA NE, the frascati factory The KLOE detector KLOE recent results: Kaon physics (mostly) Non Kaon physics Future of KLOE & DA NE Summary and conclusions V. Patera CERN seminar 28 March 2006 64
DA NE & KLOE future DAFNE upgrades physics program KLOE upgrades V. Patera CERN seminar 28 March 2006 65
DA NE : near term future 2006 – Final KLOE run (up to 2 fb-1) -shutdown for FINUDA installation -FINUDA run Only e+e- collider in Europe DAFNE scientific program scheduled up to 2008. 2007 – FINUDA run (up to 1 fb-1) -shutdown for SIDDHARTA installation -SIDDHARTA run Upgrades have been proposed and submitted to INFN. Explicitely mentioned in the 3 -years “ROAD-MAP” 2008 – SIDDHARTA run (up to 1 fb-1) -shutdown for FINUDA installation -Final FINUDA run (up to 2 fb-1) V. Patera CERN seminar 28 March 2006 of INFN
DA NE Upgrade – short term (3 years) Starting from 1. 5 x 1032, 2 fb-1/year: Reduction of e- ring beam impedance (by a factor 2) : Removal and shielding of the broken Ion-Cleaning-Electrodes Higher positron current (up to 2 A), so far limited to 1. 3 A: New injection kickers Ti-Coating against electron cloud Feedback upgrades Wigglers modifications to increase Lifetime (by a factor 2): New interaction region Transfer lines upgrade (continuous injection) To be discussed: Crab cavities, waist modulation (RF quads) Expected a factor > 3 in Luminosity V. Patera CERN seminar 28 March 2006
DA NE-2: Long term upgrade (2010 ) Change of machine layout, insertion of: Superconducting cavities Superconducting wigglers Ramping Dipoles New vacuum chamber Machine can go higher in energy (up to 2. 4 Ge. V) TDR in preparation: necessary to submit the project Energy (Ge. V) 1. 02 Integrated Luminosity per year (fbarn-1) >10 Total integrated luminosity (5 years, fbarn-1) >50 >3 >8 1032 >1032 Peak luminosity (cm-1 sec-2) V. Patera CERN seminar 28 March 2006 2. 4
The KLOE future: KLOE-2 An Espression of Interest for the continuation of the KLOE has been presented. The physics program is focused on KS physics , , ’ physics and quantum interferometry studies. Time schedule and luminosity foreseen are 30 fb-1 on tape within 2014 11 institution x 7 nations involved V. Patera CERN seminar 28 March 2006
KLOE 2: perspectives for Kaon physics Lint= 20 -50 fb-1 Competitive on rare KS decays, CPT and DS= DQ violating parameters, interesting for CHPT Present @20 fb-1 @50 fb-1 KS 0 0 0 CP, CPT < 1. 2 10 -7 KS e CPT, DS= DQ (7. 09 0. 10) 10 -4 As CPT (1. 5 11) 10 -3 KS + - 0 KS e+e- cpt KS 0 e+e- KL CP KS cpt < 5 10 -9 0. 2 10 -5 2 10 -3 (3 1) 10 -7 < 1. 4 10 -7 0. 4 10 -7 < 2 10 -8 (6 3) 10 -9 (2. 78 0. 07) 10 -6 seen 0. 03 10 -6 BR(K±e 2)/BR(K± 2) SM test (2. 416 0. 053) 10 -5 <% rel. err seen 0. 1 10 -5 1 10 -3 0. 3 10 -7 < 9 10 -9 2 10 -9 0. 02 10 -6 few ‰ rel err Assuming/extrapolating present KLOE efficiencies/systematics V. Patera CERN seminar 28 March 2006
KLOE-2: perspectives for & scalars physics -factory = ed ’ factory BR( ) = 1. 3 × 10 -2 N (20 fb-1) ~ 9 × 108 BR( ’ ) = 6. 2 × 10 -5 N ’(20 fb-1) ~ 5 × 106 Monochromatic prompt photon: clear signature Ch. PT, study of spectrum , ’ l+l-, lll(‘) e+e expected 3000 events (Dalitz & double dalitz decays) with high statistics test of CP violation beyond SM ’ sensitive to expected 200. 000 events With 20 fb-1 f 0 , f K+K- (KK) (expected BR ~ 10 -6(-8) ) well measured (105 K+K- and 103 KK), direct measure of the gf. KK coupling V. Patera CERN seminar 28 March 2006
KLOE 2: Kaon interferometry: main observables mode measured quantity V. Patera CERN seminar 28 March 2006 parameters
KLOE 2: detector upgrades The KLOE efficiency/systematics can be improved, increasing quadratically the collected events both via the tag and via the signal emisphere. The KLOE experience suggest as upgrades of the detector Use of a lower magnetic field. This can increase acceptance for several of the above mentioned channels and ease pattern recognition (. 5 T→. 3 T →x 2 gain in acceptance on KSl 3) Insertion of a vertex chamber. At present, first tracking layer is at 30 cm (i. e. 50 S) from the I. P. Increase the KS, K± geometrical acceptance Increase calorimeter’s readout granularity. Can improve photon counting, as well as particle identification (e/ / ). A small angle tagger for physics V. Patera CERN seminar 28 March 2006
Outline Physics @ peak DA NE, the frascati factory The KLOE detector KLOE recent results: Kaon physics (mostly) Non Kaon physics Future of KLOE & DA NE Summary and conclusions V. Patera CERN seminar 28 March 2006 74
Conclusions Ø KLOE has integrated 2. 5 fb-1 during its data taken at DA NE Ø During 2005 -2006 published results leading to substantial improvement to VUS, TCPV, hadr Ø Analysis of approx. 2/3 of the data set on-going Ø An Eo. I for the continuation of the KLOE physics program at an improved DA NE has been presented V. Patera CERN seminar 28 March 2006
SPARES V. Patera CERN seminar 28 March 2006 76
Bfield & reconstruction eff: KS e decays Magnetic field value dramatically affects signal acceptance. Can improve up to a factor ~ 2 (KLCrash + Ks DC selection) 0. 2 T. Spadaro 0. 15 0. 1 Proper balancing with consequent loss in momentum resolution yet to be studied Present analysis, MC with 0. 05 detailed field map 400 pb MC with LSF=0. 5, with uniform axial B field 0 3 5 B (k. G) 4 V. Patera CERN seminar 28 March 2006
KS 3 0 decays Background mostly due to photon clusters double splittings Preliminary studies show that there is room for “algorithmic” improvements in background rejection without big losses in signal efficiency Study of the entire KLOE data set crucial for a better assessment of the real potentialities of the analysis Ideally, with 20 fb 1 one can reach a limit ~ 5 x 10 9 With 50 fb 1 one could hope to observe a few events! V. Patera CERN seminar 28 March 2006
KS + 0 : a test for Ch. PT predicts B(Ks + 0) = (2. 4 ± 0. 7)x 10 7 The present experimental value (3. 3 +1. 1 0. 9 ) x 10 7 is the average of three different measurement each individually precise at ~ 40% A preliminary KLOE analysis obtains sig ~ 1. 3%, S/B ~ 2 Assuming No further effort made to reduce background Further efforts completely remove background Error on BR @ Error on BR 2 fb 1 (%) 20 fb 1 (%) @ Error on BR 50 fb 1 (%) ~ 60% ~ 20% ~ 12% ~ 40% ~ 12% ~ 8% V. Patera CERN seminar 28 March 2006 @
KS + 0 as a pedagogical example This is the typical case where analysis would greatly benefit from simple detector upgrades At least one of the two tracks has low momentum: 65% of signal lost only due to acceptance Acceptance can be increased by the use of a lower B field Also the use of a vertex chamber could definitely help Both can be useful also for the rejection of the background due to patological charged kaon events V. Patera CERN seminar 28 March 2006
KS 0 e+e decays Fundamental to assess indirect CPV contribution to parent KL decay Measured by NA 48 on the basis of 7 events (plus 6 + ) BR = (5. 8 ± 3) x 10 -9 Theoreticians’ dream: measurement at 15% accuracy What efficiency can reasonably be expected for KLOE? V. Patera CERN seminar 28 March 2006
KS 0 e+e decays Further selection based on cuts on 5 independent variables signal MC MC signal DATA 400 pb 1 e+e inv. mass V. Patera CERN seminar 28 March 2006 DATA 400 pb 1 2 kinem. fit
KS 0 e+e decays Cuts tuned on MC: 0 events retained < 4. 8 ev / fb 1 @ 90% CL Detailed studies of problematic topologies: single dalitz : 880 pb 1 : 0 events < 2. 6 ev / fb 1 double dalitz: 4200 pb 1 : 0 events < 0. 55 ev / fb 1 K +K : 880 pb 1 : 0 events < 2. 6 ev / fb 1 Overall efficiency on signal: 4. 3% Check on data (~ 400 pb 1) : 0 observed (0. 12 expected) Optimistically (no further bkg) ~ 5 events observed in 20 fb 1 V. Patera CERN seminar 28 March 2006
Prospectives for Interferometry Mode Parameter Best measurement or PDG-04 fit KLOE-2 L=100 fb-1 Dm 5. 288 ± 0. 043 109 s-1 ± 0. 02 STAT 109 s-1 0 0 Re( ’/ ) (1. 67 ± 0. 26) 10 -3 ± 0. 2 STAT 10 -3 0 0 Im( ’/ ) 0. 0012± 0. 0023 ± 0. 0022 STAT e AL (3322± 58 ± 47 ) 10 -6 ± 18 STAT 10 -6 e e Re(d. K) (0. 29 ± 0. 27) 10 -3 ± 0. 2 STAT 10 -3 e e Im(d. K) (0. 24 ± 0. 50) 10 -4 ± 20 STAT 10 -4 V. Patera CERN seminar 28 March 2006
Perspectives for , ’ at DA NE-2 -factory = ed ’ factory BR( ) = 1. 3 × 10 -2 N (20 fb-1) ~ 9 × 108 BR( ’ ) = 6. 2 × 10 -5 N ’(20 fb-1) ~ 5 × 106 Monochromatic prompt photon: clear signature Mixing – ’: Uncertainty dominated by systematics; improvement can come by measuring main ’ BR’s decays: (test Ch. PT; major improvements expected with 20 fb-1) Dalitz decays: e+e- , , e+e- Transition FF e+e- (Test of CP violation, analogous to KL e+e- ) Improvements on forbidden/rare decays ’ decays: Dalitz plot of ’ + - scalar amplitude ’ first observation / isospin violation V. Patera CERN seminar 28 March 2006
KS e : CPT test KS e amplitudes e HW K = a b b=d=0 if CPT holds e HW K = c d e HW K = c* d* c=d=0 if S= Q holds e HW K = a* b* • Sensitivity to CPT violating effects through charge asymmetry AS = 2(Re Re Re y Re x ) AL = 2(Re 1 2 CP CPT in Remixing Re y decay M 11 M 22 i x ) m. S m. L i S L V. Patera CERN seminar 28 S Q Re and CPT Re y = Re b/a Re x 2006 = Re d*/a March 86
Semileptonic decay amplitudes: definitions CP =0 =0 a b c d CPT violation: S= Q violation: T =0 =0 CPT =0 =0 S= Q =0 =0 CPT violation & S= Q violation : V. Patera CERN seminar 28 March 2006 87
KL CP violation Number of KL from fit of Number di KL from fit of V. Patera CERN seminar 28 March 2006 88
CPT test: accuracy on i We get the following accuracies on each term of the sum: 10 -4 KS S L B(KLl 3) AS+AL)/4 i Im x Im Re 00 KS K S S L KL V. Patera CERN seminar 28 March 2006 89
CPT test: m(K)-m(K) Ge. V KLOE (K)- (K) CPLEAR m(K)-m(K) Ge. V 1 2 M 11 M 22 i m. S m. L i S L Ge. V ( m) ~ 2 10 Ge. V ( ) ~ 4 10 Ge. V V. Patera CERN seminar 28 March 2006 90
Comparison of e+e- experiments 2 contribution to a hadr PLB 578 (2004) 285 JETP, Vol. 101, No 6 (2005) 1053 interpolation of 60 KLOE data points from 0. 35 to 0. 95 Ge. V 2 [0. 37 -0. 93 Ge. V 2] / KLOE - 1 Comparison with recent e+e Data CMD-2 (‘ 04) CMD-2 EPS (‘ 05) preliminary SND (‘ 05), KLOE (‘ 05) a [10 -10 ] M 2 (Ge. V 2) • CMD-2 (‘ 04) and KLOE agree @ high M • some disagreement btw. KLOE and CMD-2/SND on the peak • fair agreement btw all 4 data sets CMD-2 and KLOE agree within 0. 5 • disagreement btw KLOE and SND ca. 1. 5 V. Patera CERN seminar 28 March 2006 91
mass measurement : the method Using the decays: E 3 cross checking purpose A kinematic fit is performed imposing: Px, Py, Pz, Etot t-r/c of clusters conservation compatible with light velocity E 1 E 2 As a consequence of the kinematic fit the mass measurement is almost independent from the energy of the clusters, it is dominated by the cluster positions. The momentum and the vertex position are precisely determined run by run from the study of the Bhabha scattering at large angle e +e- e+e – (90000 events for each run). Absolute scale determined buy line shape and mass V. Patera CERN seminar 28 March 2006 92
Prospects for small angle analysis Analysis of the new data (2 fb ): take advantage of larger statist Change strategy normalizing to Differently from the old analsyis statistics is an issue, due to the small cross section in some S bins Many systematics cancel out on theory side: ′ ′ Luminosity, VP , radiator or reduce to small corrections on the experimental side tracking , vtx efficiencies ′ and trigger veto Improvements also on Filter/ECL strategies V. Patera CERN seminar 28 March 2006 93
Neutral kaons tagging: KS “beam” KS Clean KS tagging by time-of-flight KL “crash” identification of KL interactions in the calorimeter : tof(KL) ~30 ns tof ( ~6 ns) KL velocity in the rest frame 0. 218 Tagging efficiency tag, total~ 30% 1. 4 108 tagged KS Kinematic closure of the event * (p. S=p -p. L): KS angular resolution: ~ 1° (0. 3 in ) KS momentum resolution: ~ 1 Me. V/c V. Patera CERN seminar 28 March 2006
o Both the particles not Mtrk [Me. V] identified as electrons Cut on 2 in the hyp. Cut on Track. Mass vs. M 2 Cut on angle m m <130 o, E >50 Me. V ) KL OE d. N/d. M 2 @ large angle (50 < – MC pr eli m ina ry M 2 [Ge. V 2] L = 240 pb-1 – MC - MC 2 2 m M [Ge. V ] M 2 [Ge. V 2] The spectrum extends down to the 2 -pions threshold 10 times more statistics on tape! V. Patera CERN seminar 28 March 2006 95
Forward-backward asymmetry 90 o + - system: A(ISR) C-odd A(FSR) C-even an asymmetry is expected in the variable: test of s. QED via comparison data/MC MC f 0 kk model f 0 ‘no str’ a /2 no f 0 A(f 0) C-even Pion polar angle [o] 20 o< o <160 45 o< <135 o Issue: to distinguish the effect of the interference (described in our MC by s. QED ) and the effect of f 0(980). M [Ge. V] Czyż, Grzelińska, Kühn, Phys. Lett. B 611(116)2006 V. Patera CERN seminar 28 March 2006
: experimental picture The Particle Data Group measures are not in agreement = (12. 385± 0. 024)ns V. Patera CERN seminar 28 March 2006
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