October 19, 2006 CHIPP Bern Augusto Ceccucci/CERN1 Future of Kaon Physics Augusto Ceccucci/CERN J-PARC  hypernuclei K Rare Decay U-70  factory Hadron xsec K S decays N ff CERN-SPS Rare K decays LFV Chiral dynamics Frequent K decays

October 19, 2006 CHIPP BernAugusto Ceccucci/CERN2 CKM Unitarity and Rare Kaon Decays The unitarity of the CKM matrix can be expressed by triangles in a complex plane. There are six triangles, one is more “triangular”: V ud V ub *+V cd V cb *+V td V tb *=0 It is customary to employ the Wolfenstein parameterization: V us ~ V cb ~   V ub ~   i  V td ~   i  Sensitive to |V td | CP It is important to check that the unitary triangle is the same for all heavy quarks. The s-quark is just as important as the b-quark. If experiment shows that there are differences between the flavors this would be an important discovery.

October 19, 2006 CHIPP BernAugusto Ceccucci/CERN3 The Global Contest of Flavour and CPV Re  ’/  Dm  m Bs Sin 2    What will we learn next??

October 19, 2006 CHIPP BernAugusto Ceccucci/CERN4 Forward Look (Personal Choice) Quantity Exp  Sin2  Peng )~0.05 Belle/Babar  Bs )~0.02 LHCb   (B  DK) LHCb B (s)     (SM sens.) LHC  (BR(K +   ))~ 0.10 P326 (NA48/3) BR(K 0   ) (SM sens.) J-PARC  (BR(B  Super-B Year: 20XX

October 19, 2006 CHIPP BernAugusto Ceccucci/CERN5 K→  : SM Theoretical Prediction charm contribution NNLO Buras, Gorbahn, Haisch, Nierste hep-ph/ top contributions NLO Calculation: Buchalla & Buras: 1993, 1999 Misiak, Urban: 1999 The uncertainty of the SM prediction is mostly due to uncertainty of the CKM parameters and not to hadronic matrix elements: BR(K +  + )  (1.6×10 -5 )|V cb | 4 [  2 +(  c -  ) 2 ]  (8.0 ± 1.1)× BR(K L  0 )  (7.6×10 -5 )|V cb | 4  2  ± 0.6  ×10 -11

October 19, 2006 CHIPP BernAugusto Ceccucci/CERN6 MFV: Sensitivity to Z 0 Penguin from Bobeth et a. (2005) 14.4 < q 2 (GeV 2 )< 25 1 < q 2 (GeV 2 ) < < q 2 (GeV 2 ) < 1 E  > 1.8 GeV

October 19, 2006 CHIPP Bern Augusto Ceccucci/CERN7 K 0 L    BNL stopped In Japan a step by step approach is proposed: KEK: –E391a has completed data taking (three runs) –Present limit < %CL –Aim to reach the Grossman-Nir bound (~10 -9 ) J-PARC (>2010) –Proposal for the J-PARC hadron facility –Step I: move the improved E391a detector at J-PARC; To reach SM sensitivity Received J-PARC PAC stage I approval –Step II: build a new detector and a dedicated beam-line to be able reach ~ 100 SM events CERN –Evaluating capabilities in the context of an upgraded proton complex

K 0 L    at J-Parc Improvements w.r.t. E391a: CsI calorimeter with a finer granularity New photon veto in the beam Waveform digitization for higher rates

October 19, 2006 CHIPP BernAugusto Ceccucci/CERN9 K + →  + : setting the bar for the next generation of experiments 100 events Mean=SM 100 events Mean=E787/949 Current constraint on  plane ? E787/E949: BR(K + →  + ) = ×

October 19, 2006 CHIPP BernAugusto Ceccucci/CERN10 Plans for K + →  + Decays at rest: –There is a Letter of Intent to continue K + →  + studies with kaons decays at rest at J-PARC –The plan is to move the BNL-E949 detector to Japan to study Hadron Nuclear Spectroscopy at the Spring-8 LEPS2 photon source –Then, the detector could be moved to J-PARC when/if a low energy K + line becomes available Decays in flight: –Not anymore pursued at FNAL –There is a proposal with a sensitivity to collect about 80 SM events in two years at the CERN-SPS –The proposal (P-326) builds on the infrastructure of the current CERN kaon experiment (NA48/2) and is also known as NA48/3

October 19, 2006 CHIPP Bern Augusto Ceccucci/CERN11 Proposal to Measure the Rare Decay K     at the CERN SPS CERN, Dubna, Ferrara, Florence, Frascati, Mainz, Merced, Moscow, Naples, Perugia, Protvino, Pisa, Rome, Saclay, San Luis Potosi, Sofia, Turin CERN-SPSC SPSC-P-326 Presented at the CERN SPSC in September 2005 R&D endorsed by CERN Research Board on December 2005 Test beams in Oct-Nov 2006 Seeking more groups to join Aims to complete R&D by the end of 2007…. …to start data taking in 2011

October 19, 2006 CHIPP Bern Augusto Ceccucci/CERN12 CERN Proton Complex NA48 SPS LHC CNGS CERN Proton Complex

October 19, 2006 CHIPP Bern Augusto Ceccucci/CERN13 NA48

October 19, 2006 CHIPP Bern Augusto Ceccucci/CERN14 P-326 Detector Layout SPS primary p: 400 GeV/c Secondary beam: 75 GeV/c 800 MHz  /K/p (~6% K + ) K+K+ ++ ~11 MHz of K + decays (KABES) K     SPIBES: Si  pixel X/X 0 << 1% per station Pixel size ~ 300 x 300  m excellent time resolution

October 19, 2006 CHIPP Bern Augusto Ceccucci/CERN 15 Background rejection 1) Kinematical Rejection 2) Photon vetoes to reject K +  +  0 : P(K  ) = 75 GeV/c Requiring P(   ) < 35 GeV/c P(   ) > 40  GeV/c It can be hardly missed in the calorimeters!! 3) PID (RICH) for K +  +  rejection

October 19, 2006 CHIPP Bern Augusto Ceccucci/CERN 16 Signal & backgrounds from K decays / year* TotalRegion IRegion II Signal (SM) K++0K++0 2.7±0.21.7±0.21.0±0.1 K2K2 1.2±0.31.1±0.3<0.1 K e4 2±2negligible2±2 K   +  +   and other 3-tracks bckg. 1±1negligible1±1 22 1.3±0.4negligible1.3±0.4 K2K2 0.4±0.10.2±0.1 K e3, K  3,othersnegligible  Total bkg9±33.0±0.26±3 SPS used as LHC injector (so it will run in the future) No flagrant time overlap with CNGS P-326 fully compatible with the rest of CERN fixed target Conservative beam request based on decennial NA48 experience at SPS * Before taxes. Proposal quotes a more conservative

October 19, 2006 CHIPP Bern Augusto Ceccucci/CERN17 LKr inefficiency measured with data Cluster not reconstructed E  = 22 GeV Pion P=42 GeV/c Photon E=11 GeV Expected position   track and lower energy  are use to predict the position of the other  LKr ineff. per  (E  > 10 GeV):  ~ 7 × (preliminary) K +      selected kinematically Just collected tagged  to measure  for E  < 10 GeV using an e - beam and the NA48 DCH’s as active target

October 19, 2006 CHIPP Bern Augusto Ceccucci/CERN18 Other Physics Opportunities The situation is similar to NA48, which was designed to measure “only”  ’/  but produced many more measurements Accumulating ~100 times the flux of NA48/2 will allow us to address, for instance: 1.Cusp like effects (  scattering) –K        , K       e  2.Lepton Flavour Violation K        e , K       e +, R K =  (K   e   /  K      3.Search for new low mass particles –K      X –K       P (pseudoscalar sGoldstino) 4.Study rare     decays 5.Improve greatly on rare radiative kaon decays 6.Compare K + and K - (alternating beam polarity) –K        (CPV interference) –T-odd Correlations in K l4 7.And possibly, given the quality of the detector, topics in hadron spectroscopy Example I Example I I

October 19, 2006 CHIPP Bern Augusto Ceccucci/CERN19 Example I: Observation of  scattering effect in K→3  decays 1 bin = GeV 2 K ±  ±  0  0 4m π M events 4m π + 2 NA48/2 has made the first observation the of the charge exchange process  +    0  0 in the K   0  0   decay. M 2 (  0  0 ) (GeV/c 2 ) 2 NA48/2 PLB 633 (2006) hep-ex/ N. Cabibbo, hep-ph/ PRL (2004) N. Cabibbo and G. Isidori, hep-ph/ JHEP 503 (2005) G. Colangelo, J. Gasser, et al. hep-ph/ PLB 638 (2006)  ~|M 0 +M 1 | 2

October 19, 2006 CHIPP Bern Augusto Ceccucci/CERN20 Difference between  scattering length in I=0 and I=2 states (a 0 – a 2 )m + = ± 0.010(stat) ± 0.004(syst) ± 0.013(theor) In agreement with theory (a 0 – a 2 )m + = ± (Colangelo 2001) NA48/2 PLB 633 (2006) hep-ex/

October 19, 2006 CHIPP Bern Augusto Ceccucci/CERN21 Masiero, Paradisi, Petronzio, hep-ph/ NA48/2 EPS05 EXAMPLE II : R K =  (K   e  ) /  (K    

October 19, 2006 CHIPP Bern Augusto Ceccucci/CERN22 P-326 Project CORE Cost ~26 MCHF –Including about 3.7 MCHF for online/offline computing Cost drivers: –Photon Vetoes: 5.0 MCHF –RICH: 3.0 MCHF –Magnets: 3.0 MCHF –Gigatracker: 2.9 MCHF (0.13  m CMOS) Completion of R&D and TDR submission during 2007 Construction time –It is a window of opportunity between the completion of the LHC detectors and before the LHC upgrade (SLHC) –A step-by-step upgrade of the to experimental setup allows one to address LFNV and other topics before the full construction of P-326 Data taking with full detector from 2011 The consolidation/upgrade of the CERN proton complex enthuses to also think about an K 0 L   

October 19, 2006 CHIPP Bern Augusto Ceccucci/CERN23

October 19, 2006 CHIPP Bern Augusto Ceccucci/CERN24 Why should CH Participate Outstanding physics opportunity –The importance of rare kaon decays has been recognised by the theoretical community since a long time. If these experiments are not done, we will arguably lack the cleanest test of the SM flavour sector –It is a “no lose situation”. If new particles exists, their effect must appear in loops –No other clean way to study the FCNC d  s transitions –Complementary with LHCb –Cost-effective alternative to Super-F factories With a moderate investment CH could play an essential role –The time scale is well matched to bridge the current round of LHC experiments and the ILC/SLHC construction Small risk –The SPS is here to stay and the CERN proton complex will be consolidated –Projects such as this one add breath to the CERN Physics programme  low strategic/schedule risk –The experiment is feasible with some more R&D  moderate technical risk –The exploitation of existing CERN infrastructure keeps the tag price low  low financial risk

October 19, 2006 CHIPP Bern Augusto Ceccucci/CERN25 Summary J-PARC –Hypernuclei studies (K1.8 line “day one” experiments) –P14: K  L     (K0 beam-line, >2010) –P6: Transverse  polarisation (K         ) (K1.1BR beam-line) –P9: K      at rest (>2013) CERN-SPS: P-326 (NA48/3) –K      in-flight (Precise SM prediction, Test of MFV) –LFNV: R K =  (K   e   /  K     , K       e -, K       e +,… –Chiral dynamics (Ke4, K  4, radiative and non-leptonic kaon decays) –  Scattering –Search for new low energy particles –T-odd correlations Other labs (“frequent” decays) –IHEP Protvino (in-flight separated beam) –Frascati  factory (hadronic x-sections, K Interferometry, nucleon ff)

October 19, 2006 CHIPP Bern Augusto Ceccucci/CERN26 SPARES

October 19, 2006 CHIPP Bern Augusto Ceccucci/CERN27 Plans at the Frascati  factory Last KLOE run: 2006 DA  NE runs until 2008 for other experiments: FINUDA +SIDDHARTA Plans for Luminosity and Energy upgrades (DANAE) CM Energy (GeV) Peak Luminosity (cm -2 s -1 ) DANAE Motivation: Kaon interferometry (QM) Nuclear Physics N N form factor Synchrotron radiation R&D

28 Beamline was built in and commissioned in December 2004 IHEP Protvino: RF-separated Main beam parameters : Primary proton beam energy GeV Primary proton beam intensity ppp Secondary beam momentum 12.5 or 18 GeV Length of the beam line ~200m K   intensity at the end 5 x 10 6  +, p contamination <25% Muon halo <100 % End of the beamlineDeflector in the beamline

October 19, 2006 CHIPP Bern Augusto Ceccucci/CERN29 Expected Backgrounds (J-PARC-Step1) For 7 SM events: S/B~1.4

October 19, 2006 CHIPP Bern Augusto Ceccucci/CERN30 P-326 RICH performance P from straws RICH Radiator: STP Ne: (n-1)x10 6 =67.1 L=18 m

October 19, 2006 CHIPP Bern Augusto Ceccucci/CERN31 Theory vs. Experiment SM ObservableTheory errorExp error 2006 B(K  L    ~3%?? B(K     ~6%~75% A FB (B  X s l  l  ) ~8%?? B(B  X s  ) ~10%~9% B(B  X s l  l  ) ~13%~20% A FB (B  K ( * ) l  l  ) ~15%~30% B(B  (K ( * )  )  ) ~25%~40% B(B s      ) ~30%?? B(B  K*l  l  ) ~35%~13% Adapted from U. Flavour in the LHC era, 6-8 Feb 06, CERN

October 19, 2006 CHIPP Bern Augusto Ceccucci/CERN32 Standard Model contribution to P T : P T (SM) < Effects from final state interactions (FSI) : P T (FSI) < A large window for new physics in the region of P T = ~ T-violating Transverse Muon Polarization in K + →     Decays P T = ± (stat) ± (syst) ( |P T | < : 90% C.L. ) Im  = ± (stat) ± (syst) ( |Im  | <0.016 : 90% C.L. ) KEK-PS E246 result E246 Non-zero P T is a clear signal of T violation

October 19, 2006 CHIPP Bern Augusto Ceccucci/CERN33 Upgraded E246 experiment at J-PARC Sensitivity goal =  P T ~10 -4  P T stat ~ 0.05  P T stat ( E246 ) ~10 -4  P T syst ~ 0.1  P T syst ( E246 ) ~10 -4 Stopped K + decay SC Toroidal spectrometer Active muon polarimeter etc. E246 detector