EPSI: Status Report E. Iacopini CSN1: Assisi 21 settembre 2004 Nuovi recenti risultati da NA48/n Run 2004 (NA48/2) Run 2004 (NA48/2) Possibili sviluppi futuri Possibili sviluppi futuri

Nuovi recenti risultati …

L’unitarietà della matrice CKM

V us dal K 0 e3

…

K 0 e3 Data/MC comparison

V us dal K 0 e3 BR(K L →3   ) = ±0.0070…

V us dallo   beta decay

V us dal K + e3

V us da NA48/n

Altri risultati …

… e altri ancora …

NA48/2 (risultati dal run 2003)

 Direct CP violation in K ±   ±  +  , K ±   ±  0  0 M (u )  1 + g  u, u= (2m K /m  2 ) (m K /3 – E*  -odd ) M (u )  1 + g  u, u= (2m K /m  2 ) (m K /3 – E*  -odd )  (A g ) < 2  10 – 4 (limited by statistics) g + - g - A g = ———— g + + g -   Rare decays: to test  PT & search for A CP K e4  -  scatt. length  ( ) 10 6 events) K      , K     e + e , K      +  , K  e2, K   l  l + l , K      0 , K      0 l + l , … etc.   Semileptonic decays: K  e3, K   3 contribution to the measurement of |V us | search for f T, f S The Goals of NA48/2

E.Shabalin-98 I.Scimemi-04 A g : theory & experimental limits 1.0E E E E E SUSY SM |Ag||Ag| new physics G.D’Ambrosio-97 G.D’Ambrosio,G.Isidori, G.Martinelli-99 L.Maiani,N.Paver-95 E.Shabalin-01,-04 NA48/2 experiments by 2002

1cm DFDF Quadrupole 2 nd Quadruplet ACHROMAT FRONT-END ACHROMAT 10 cm m vacuum tank He tank + spectrometer magnet B+/- K+K+ K-K- K+K+ K-K- focusing beams NA48/2 experiment configuration 114m decay volume beams coincide within <1mm FDFD P K spectra, 60  3 GeV/c The simultaneous K + and K - beamsNA48 Set-Up not to scale TAX 17 TAX 18

1cm DFDF Quadrupole 2 nd Quadruplet ACHROMAT FRONT-END ACHROMAT 10 cm m vacuum tank He tank + spectrometer magnet B+ K+K+ K-K- K+K+ K-K- focusing beams The simultaneous K + and K - beamsNA48 Set-Up NA48/2 experiment configuration alternate magnet polarity daily (’03) 3-4h (’04) FDFD not to scale TAX 17 TAX 18

1cm DFDF Quadrupole 2 nd Quadruplet ACHROMAT FRONT-END ACHROMAT 10 cm m vacuum tank He tank + spectrometer magnet B- K+K+ K-K- K+K+ K-K- focusing beams The simultaneous K + and K - beamsNA48 Set-Up NA48/2 experiment configuration alternate magnet polarity daily (’03) 3-4h (’04) FDFD not to scale TAX 17 TAX 18

1cm DFDF Quadrupole 2 nd Quadruplet ACHROMAT FRONT-END ACHROMAT 10 cm m vacuum tank He tank + spectrometer magnet K+K+ K-K- K+K+ K-K- focusing beams The simultaneous K + and K - beamsNA48 Set-Up NA48/2 experiment configuration alternate the beam lines (weekly) FDFD not to scale TAX 17 TAX 18

1cm DFDF Quadrupole 2 nd Quadruplet ACHROMAT FRONT-END ACHROMAT 10 cm m vacuum tank He tank + spectrometer magnet K-K- K+K+ K-K- K+K+ focusing beams The simultaneous K + and K - beamsNA48 Set-Up NA48/2 experiment configuration alternate the beam lines (weekly) FDFD not to scale TAX 17 TAX 18 Supersample

… Alcune definizioni … dove u = ( S 3 – S 0 ) / M   e S i : (P K - P  i ) 2 = M K 2 + M  M K E *, S 0 =  S i /3 = M       → u=(2M k /3M  2 )(M K - 3 E * ) K+ K- u distributions for K+ e K-

A g measurement A g measurement (acceptance cancellation) Physical asymmetries: Physical asymmetries:  A S → slope of ratio U(K + B+) / U(K - B-)  A J → slope of ratio U(K + B-) / U(K - B+) Z axis (beam direction) Saleve Jura X axis Top view of the setup Apparatus-induced asymmetries: A + → slope of ratio U(K + B+) / U(K + B-) A  → slope of ratio U(K - B+) / U(K - B-) A SJ = (A S +A J )/2   g = A g  2g physics asymmetries (to mask the results A SJ,A S & A J are presented with OFFSETS !)  A ± = (A + +A  )/2 = (A S -A J )/2 asymmetry induced by the experimental setup asymmetry induced by the experimental setup ( many of the effects observed in A ± cancel in A SJ ) ( many of the effects observed in A ± cancel in A SJ )

recorded events, 10 6 # of Super- Samples run K    -  +   K    0  0   (complete cycles) 2003 (I) 2003 (I) ~ 600 ~20 non-stable conditions 2003 (II) (analyzed) 2003 Statistics ~ 1 month of data taking in 2003 at stable conditions have been analyzed

|V| U Dalitz plot for K      +  - & M(3  ) odd pion in beam pipe even pion in beam pipe M 3π, GeV/c 2 Events KK K+K+ SS1-3 data: > 1120 million events selected

Asymmetry vs. P K Asymmetry vs. P K ( 1 month ’03 data): preliminary Statistical error of A : 2, Statistical error of A g : 2.7*10 -4  2 /ndf 6/11 A SJ + offset = 0 ± 0.117*10 -3  2 /ndf 6.7/11 A  = (0.131 ± 0.117)*10 -3 K±±+-K±±+- P K, GeV/c A S +offset A J +offset A+A+ A-A- (A S +A J )/2 + offset (A + +A - )/2 A g =A SJ /2g =A SJ * 2.304, essendo g = ±0.007

Asymmetry vs. time Asymmetry vs. time ( 1 month ’03 data): preliminary  2 /ndf 5.6/12  2 /ndf 13.5/12 A S +offset A J +offset A+A+ A-A- (A S +A J )/2 + offset (A + +A - )/2 Day-sample pair K±±+-K±±+-

Results on A g one month of NA48/2 data taking in 2003:  K ±   +    ± A g c = (  2.7)∙10 -4  K ±   0  0  ± (36M events) A g 0 = (  5.0)∙10 -4 uncertainties dominated by the statistical errors! Other experiment data on A g c BNL (1970): (- 7.0 ± 5.3)∙10 -3 FNAL, HyperCP –2000 (preliminary) (2.2±1.5±3.7)∙10 -3 Serpukhov data on A g 0 I.V.Ajinenko et al., PLB567(2003)159.: (5.1 ± 2.8 )∙10 -3 G.A.Akopdzhanov, hep-ex/ prelim.: (0.2 ± 1.9 )∙10 -3

Run 2004

The startup  Technical run during the week of April 19 th Smooth startup as usual Start refurbishing old tagger FADC readout for Kabes  Some clouds appeared… PS startup delayed by one week PS startup delayed by one week Need to exchange all the water pipes to the booster Kevlar window was discovered broken Kevlar window was discovered broken  No further delays PS startup was in time with the revised schedule Protons to NA48 on Friday May 14 th Spare kevlar window put back in a record time …

Kevlar window broken (courtesy of Luigi di Lella)

First period 15/5-8/6  Supersample 4 Start data taking … B field inverted every 30 million triggers  A new problem… PS septum 16 broken (water leak in the vacuum) 5 days without beam Replaced with the only spare (remember this…) Coupled to a faulty bellow in TT20 transmission line

Scrubbing & 25 nsec structure  From 8/6 to 27/6 (19 days) Maintenance during the scrubbing runs 25 nsec time used for  runs + test session for the future Different timing (2.2/12.0 seconds) Bunched structure different istantaneous intensity Tight schedule for tests Commissioning of the resurrected FADC readout for Kabes Test of a Kabes station with 25  m mesh Test of an Alice pixel chip as a high rate beam tracker Commissioning of Lkr selective readout

Second period 27/6-7/7  Supersample 5 Alternate the achromat with 3 periods (i.e. down, up, down) Better control of the number of event for each class (u/d,+-) …  But black clouds were coming back…

Second period 27/6-7/7  On July 5 th the PS septum 16 broke Yes, it was the only spare installed in May… ! The original one was foreseen to be repaired in September after a proper cool-down period It was decided to repair the original one (3 weeks) Operate without cooling during this time 1 injection batch instead of 2 11  s beam substructure Half integral intensity at the same instantaneous rate  Beam back on July 6 th, evening, with an intensity gradually approaching the nominal one Twice the instantaneous rate

Third period 7/7-19/7  Supersample 6 Still with 11  s beam sub-structure, Implement selective Lkr and HAC readout 5/16 (then 6/16) of events with only 2VTX and 1VTX not readout Improve from 52k to 60k events/burst, keeping the good number of K   +  -   at 12k The period ended with the stop (5 days) for the PS septum installation  We got an extension/compensation time 2 weeks to be shared between asymmetry data taking and test for the future

Fourth and fifth period 23/7-11/8  Supersample 7 Go back to standard beam conditions Nominal instantaneous intensity  Supersample 8  Good operating conditions

Muon runs for alignment  Muon runs more frequent than in 2003 Get better control on the time dependence of the alignment Frequency of about ten days between muon runs (except at the early stage of the run) Alignment is very stable, unlike 2003

Statistics 2004 Statistics in 10 6 K 3  charged SSDatesA+B+A+B-A-B+A-B- 4 15/5 – 8/ /6 – 7/ /7 – 19/ /7 – 1/ /8 – 11/ Total Grand total: 2.15*10 9

Futuro… EOI CERN-SPSC del LOI sarà presentata a Villars (26 sett. 2004)

Possibili scenari dopo NA48/2 (>2005) … misurare BR di decadimenti rari, come E. Iacopini CSN1:28 Gennaio 2004

Perché misurarli ?

…dal solito triangolo dello SM: Perché misurarlo ?

Predizione (CKM Workshop): BR(K + →   ) = 8.0 ± 1.1 × Sono attesi miglioramenti nel calcolo NNLO  4 % error (Buras) K + →  + : Teoria L’ elemento di matrice adronico può essere estratto dal ben misurato K + →  0 e Non ci sono contributi “long distance” all’ampiezza QCD NLO Buchalla, Buras 1999

Beam: Present K12 (NA48/2) New HI K + > 2006 Factor wrt 2004 SPS protons per pulse1 x x Duty cycle (s./s.) 4.8 / Solid angle (  sterad)  0.40  1640 Av. K + momentum (GeV/c) 6075 Total : 1.35 Mom. band RMS: (  p/p in %)  4  1~0.25 Area at KABES (cm 2 )  7.0  20  2.8 Total beam per pulse (x 10 7 ) per Effective spill length (MHz) / … / cm 2 (KABES) (MHz) ~45 (~27) ~16 (~10) Eff. running time / yr (pulses) * K + decays per year *  40 Possible new high-intensity K + beam for ‘NA48/3’ (K + →   )

Principali decadimenti in competizione con K + →  +                         e  63 % 21 % 6 % 2 % 3 % (called K +  3 ) 5 % (called K + e3 ) Soppressione:  PID, kinematics  veto, kinematics CHV, kinematics  veto, kinematics  veto,  PID  veto, E/P Veti il più possibile ermetici e misure ridondanti sono una necessità assoluta, comunque l’alta energia dei K li semplifica …

golden zone Region I Region II

NA48/3: Experimental Layout 5 MHz Kaon decays Vacuum 800 MHz (  /K/p) Only the upstream detectors see the 800 MHz beam straw Gigatracker: 2 Spibes+FlashTPC

Acceptance 20 events per BR = (Region I) Acceptance Region IRegion II 75 GeV/c 80 events/year !! But populated by 3 body decays

2004 tests …. One of the two weeks of extension/compensation has been devoted to tests for the future  Small angle veto with crystals  Kabes readout with FADC  Pixels for beam tracker  Intensity scans for Kabes (25 and 50 mm meshes)  Quartz counters for a possible new hodoscope

Small angle photon veto PbWO 4 crystals (CMS) Dimension of crystals 2x2x23 cm 3 7 x 7 cm matrix ~ 25 X 0 Readout with light guides and PMT Hard to radiation damage

725µm thick ALICE chip 300µm thick sensor Mounted on thin test-PCB Material in beam: 3.78 % X 0 Chip=0.77% X 0 Sensor=0.32% X 0 PCB=0.8% X 0 V fd =21V V op =30V 2 x 8192 pixels Pixel Assemblies ALICE Pixel Assemblies tested in August 04 in NA48

Charged hodoscope Time resolution, together with CEDAR and Gigatracker ≈ 100ps We are considering a design in which the scintillator, orthogonal to the beam axis, is seen by PMs disposed along the beam Another possibility could be to look at the Cerenkov light from a slab of fused silica Glass RPC as ALICE ?

Cerenkov (CEDAR) K/  Cedar-W Cedar-N Test foreseen during October 2004 run, together with Compass Cerenkov differential counter Highly parallel beam

NA48/3: Veti per i fotoni Disegno KTeV/CKM Sandwich 1 mm piombo 5 mm scintillatore E` auspicabile, ma resta da dimostrare, che lavorando ad energie piu` alte si possano rilassare le richieste rispetto a CKM BR(K + →  +  0 ) ~10 10  BR(K + →  + ) Non c’e` rischio di enfatizzare troppo questo fatto:

Muon rejection Better than rejection inefficiency mandatory obtained by NOMAD We are designing a new detector (MAMUD) incorporating: Hadron calorimetry Muon Rejection Sweeping Magnet

Previsione sui tempi NA48/3 Tentative timescale: 2004 Definition of the new detectors and cost estimation 2005 Prototype tests of the new items Proposal for SPSC 2006 TDR submission 2007 Construction 2008 Construction 2009 Data Taking

K + →  + E949 Continuazione di E787(dec. a riposo) 12 settimane di presa dati nel 2002: Analisi in corso, ci si auspica: –Sensitivita` Regione II molto migliorata –Sensitivita` (I + II) 2002 simile a quella di E787 Approvati per 60 settimane… –Ma… nessuno sa se e quando l’esperimento continuera` la presa dati Lettera di intenti a J-PARC basata sulla stessa tecnica.

Proposta per misurare ~100 K + →  +  (in volo) Ridondanza: spettrometri magnetici e RICH (per K e  ) Il necessario R&D e` stato completato: – –Costruito prototipo di SCRF per il fascio di K separato (22 GeV/c) – –Inefficienza dei veti per fotoni e` 5×10 1 GeV (misurata) Un fattore 6 meglio del necessario – –Operazione in vuoto dei tubi a “straw” dimostrata HEPAP-P5 non ne ha ratificato l’approvazione per ragioni di costo

E` il primo esperimento dedicato per cercare K L →    SES~ Basato su veti ermetici a fascio neutro molto collimato Presa dati (~100 giorni) durante il 2004 Questa iniziativa potrebbe continuare a J-PARC

(2009?) Si propone di raccogliere ≈ 60 K L →    con Segnale/Fondo ~2 (Im t ~ 15%) Misurare tutto quanto possibile: –Energia, Posizione ed angolo per ogni fotone Lavorare nel centro di massa –Fascio AGS con microstruttura –Uso del tempo dI volo per misurare l’impulso del K L Inizio costruzione nel 2005.