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Status of the NA62 project

Status of the NA62 project. Mauro Raggi for NA62 LNF group : A. Antonelli , M. Moulson , M. Raggi, T. Spadaro

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Status of the NA62 project

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  1. Status of the NA62 project Mauro Raggi for NA62 LNF group: A. Antonelli, M. Moulson, M. Raggi, T. Spadaro E. Capitolo, C. Capoccia, A. Cecchetti, G. Di Raddo,B. Dulach, R. Lenci, G. Corradi, B. Ponzio, C. Paglia, M. Santoni, D. Tagnani, S. Valeri, thanks to V. Lollo, R. Diraddovacuum experts 41st Meeting of the LNF Scientific Committee LNF November 22, 2010

  2. Outline • NA62 experiment at CERN • The Large Angle Veto system of NA62 (LAV) • LAV construction activity at LNF • The LAV front end electronics • ANTI-A2 2010 test beam results • Time resolution • Energy resolution • The NA62 RK measurement improvements

  3. K++nnin the Standard Model The Knndecays are the most precisely calculated FCNC decays: • Dominated by top quark (charm significant, but controlled) • Hadronic matrix element shared with well measured K+0e+n • Largest uncertainty from CKM elements • Even small NP effect can be observed BRSM(K++nn) = (8.22 ± 0.75)x1011 J. Brod, M. Gorbahn, E. Stamou arXiv:1009.0947

  4. K++nnbeyond the SM Present experimental knowledge based on 7 events E787+E949: Deviations from SM by more than 10% quite possible in many NP models

  5. NA62 Collaboration CERN TRIUMF • Birmingham • Bristol • Glasgow • Liverpool • Ferrara • Florence • LNF • Naples • Perugia • Pisa • Rome I • Rome II • Turin • IHEP • IINR • JINR Bucharest* • San Luis Potosi • Gomel* • Minsk HEP* • Minsk INP* Mainz • George Mason • SLAC • UC Merced Bratislava Sofia UCL Louvain ~150 physicists from ~30 different institutions Proposed as P326 @ SPSC in 2005 Approved by CERN December2008 Approved by INFN July 2009 Synchronization run Oct-Nov 2011 First physics run foreseen in 2013 Version 0 circulated in Sept. Final version in print in December

  6. NA62 Beam & Detectors INFN • SPS primary p: 400 GeV/c • Unsepareted beam: • (75±1) GeV/c • 750 MHz • p/K/p (~6% K+) LAV: Large Angle Photon Veto Sofia CERN SAV Small Angle Veto Beam Line + Infra. • IHEP • INR CHOD Charged Hodoscope INFN CHANTI Target UK CEDAR p+ K+ n n Gigatracker (GTK) LKr MUV • Measure Kaon: • Time • Angles • Momentum CERN Straw Tracker RICH Mainz Decay Region 65m INFN INFN IHEP INR Belgium JINR Mexico CERN Total Length 270m US

  7. The photon veto system INFN LAV: 8-50 mrad Large Angle Photon Veto SAC Small Angle Calorimeter Target p+ K+ p0 g g LKr 1-8 mrad Decay Region 65m Collect photons from dominating p+p0decay Provide full coverage form 50 to 0 mrad Inefficiency on p0detection of ~10-8 LAV to be operated in 10-6 mbarvacuum region IRC Intermediate ring calorimeter

  8. LNF responsibilities • LAV Mechanical design • Construction tooling • Installation procedures • LAV stations construction and quality control • LAV front end electronics • Design and production • Performance tests and assembly • Detector commissioning • Coordination of entire photon veto system

  9. LAV technology choice Technology chosen after extensive tests @BTF, comparing: A Pb/scintillating fibres prototype built at LNF APb/scintillating tile prototype from the CKM exp. The response of PbGl SF57 blocks from OPAL Detection efficiency measured in test beams:figure satisfies requests,will re-use PbGl (economy + blocks built and available)

  10. NA62 Large Angle Veto A1-A11 Vacuum • 12 LAV stations mounted along 120 meter decay region 6 meters apart • 4 different station types: • ANTI-A1 to A5 160 blocks; 5 layers in vacuum • ANTI-A6 to A8 240 blocks; 5 layers in vacuum • ANTI-A9 to A11 248 blocks; 4 layers in vacuum • ANTI-A12 256 blocks; 4 layers in air • Angular coverage 8-50 mrad • Inefficiency < 10-4from 0.2 GeV to 35 GeV • Sensitive elements: 2500 OPAL barrel calorimeter lead glass blocks • Efficiency measurements with electron @BTF in 2007:1-e<10-4 for 200 MeV<E<500 MeV

  11. In vacuum operation studies • Original OPAL PMT were not built to be operated in vacuum: • Heating of the PMT divider in vacuum investigated • Maximum temperature reached by the divider 60 °C • Well below components safety limit • The LAV will bring a lot of material in the evacuated decay region: • Measured single component outgassing rates • Outgassing rate per single ANTI station 1.510-3mbarls-1 • Outgassing rate for the whole LAV system 2.510-2mbarls-1 • The predicted values are compatible with direct measurement on ANTI-A1

  12. Improving PMT performance Oscillating behavior observed in the original OPAL dividers due parasitic inductance on last dynodesThis causes refirings in the LAV FE electronics New divider Effectofnewdividers Original opal divider LNF new divider

  13. Single block operation and test Test the PMT: Light Yield Gain curve Equalization voltage Glue plates to strengthen the original bond between lead glass block and steel PMT mounting More than 700 blocksalready processed Replace original OPAL dividers with new one projected @ LNF

  14. LAV assembly procedure Mount structure of four blocks called “bananas”Mount the LED for the monitoring systemRoute and fix the cables in the structures Close the vessel and perform vacuum leak and outgassing test. Fill the vessel with 5 layers of 8 “bananas”Route the cables to the flanges

  15. LAV construction status • A1 completed and tested in 2009 • A2 completed and tested in summer 2010 • A3 assembly finished last week • Final cabling, flanging and tests in progress • A3 will ship to CERN on 29 November • A4 vessel will be delivered on November 29th. • All A4 internal components ready for installation • A4 delivery to CERN expected in January 2011 • A5 vessel construction of is nearly  complete; • About half of internal components are finished. • Design of ANTI-A6 to A8 and A11 complete A11 4 layers ∅299 cm A6-8 5 layers ∅259cm

  16. LAV Front end Electronics

  17. FE time over threshold technique • Requirements for LAV front end • Dynamic range from 0.1-30 GeV • Manage signals from 25mV-10V • s(t)<1ns and s(E)/E~10%/√E • Equip 2500 channels • Measurement technique • Clamp the analog signal • Compare with 2 different threshold • Produce LVDS signals with the ToT width • Measure the width of the LVDS using a TDC • Use a Q=f(ToT) to reconstruct the charge • Prototype VME6U card produced at LNF • 8 input and 16 output channels • Final ToT mezzanine • (clamping/amplifier/splitter/2 discriminators) • Manual threshold adjustment • No interface

  18. Test beam setup (PS-T9) T9hadron beam:Electrons0,5 –5GeVselectedusingthresholdcherenkovcounters. Muons up to8GeV • Validate final version of FE and new voltage divider: • Time-over-threshold vs. charge calibration curves • Efficiency vs. threshold for electrons, hadrons and muons • Measure time and energy resolution • Test new FEE with TELL1 readout

  19. A2 Energy resolution and linearity Select electrons using 2 beam Cerenkov counters (TDC & QDC):Operated at two different pressures to select electrons in a given P range: Q(pC) Good linearity and energy resolution better than 10%/√E up to 2 GeV ToT(ns)

  20. A2 Time resolution Electrons, first hit block. Time slewing fit and corrected Time resolution after time slewing correction for single block ~500ps @ 1GeV

  21. LAV veto readout chain • 32 analog channels inputs • 64 LVDS channels output • VME 9Umechanics 400x400 mm2 • Include services: • Analog sums of 4 and 16 blocks • Remote threshold • Individual channel threshold control • Pulsing system Front end board LNF A custom version of LHCb TELL1 board will house the TDC boards, manage the data transfer to PCs and produce the L0 primitives.

  22. Status of RK=Ke2/K2 measurementin NA62 phase I (2007-2008)

  23. RK=G(Ke2)/G(Km2) in the SM Sensitive to lepton flavor violation and its SM expectation: Few % due to: K->en(g) IB process Helicty suppressionfactor ~10-5 • SM prediction:excellent sub-per-milaccuracy due tocancellation of hadronic uncertainties. • Measurements of RK has long been considered as tests of lepton universality. • Recently understood: helicity suppression ofRK might enhance sensitivity to non-SM Theoretical expect. (Phys. Lett. 99 (2007) 231801): RKSM = (2.4770.001)10–5

  24. RK beyond the SM 2 Higgs Doublet Models – tree level Kl2 can proceed via exchange of charged Higgs H±instead of W± Does not affect the ratio RK 2 Higgs Doublet Models – one-loop level Dominant contribution to RK: H±mediated LFV (rather than LFC) with emission of   RKenhancement can be experimentally accessible 3 unknown parameters: MH±, D13, tan b Effect in large tanregime with a massive H± (PRD 74 (2006) 01170) (13=510–4, tan=40, MH=500 GeV/c2) lead to RKMSSM = RKSM(1+0.013) 1.3% measurable!

  25. LNF contributions to RK analysis For a ~5 per-mil measurement, keep under control radiative corrections: 1. Ke2g(DE) background is of the same order of Ke2g(IB): Rejection via cut on Mmiss, residual bkg from KLOE measurement of DE 2. For a precise evaluation of Ke2g(IB) acceptance: Resum multi-photon energy spectra in the MC, a correction of ~% 3. Lessen effect of additional g in final state to selection efficiency: Veto Ke3 while ignoring collinear g’s from IB/from e- external radiation. Implement method using Ke3g, get as by product powerful check from data: material budget efficiency of electron identification cut via E/P 4. Selected data to be fit as Ke2+Km2+Ke3 Best statistical accuracy achievable Evaluation of mmis-id probability from data 5. Suggest the correct interpretation of Km2 trigger downscaling effect

  26. June 2010 result (40% data set) (arXiv:1008.1219) Backgrounds RK = (2.486 ± 0.011stat ± 0.007syst)  10–5 RK = (2.486 ± 0.013)  10–5 60K Ke2 candidates, 8.8% background SM Systematic uncertainties Independent measurementsin lepton momentum bins Result presented at BEACH 2010 Perugia, June ‘10arXiv:1008.1219, acc. by Nucl. Phys. B Proc. Supp.

  27. Conclusions • A lot of activity during 2010: • 2 LAV station assembled ANTI-A2, ANTI-A3 • Design of ANTI-A6 to A8 • New PMT dividers projected and mounted successfully • Front end electronic prototypes successfully tested • Final result of 40% of the statistics achieved for RK • Plans for 2011 activity: • Build A4,A5, A6, A7 • Mount of the 4 ANTI stations in the NA62 at CERN • Production of a first part of the front end electronics • Test the whole system in the synchronization run

  28. Spares

  29. The NA62 Collaboration • Birmingham • Bristol • Glasgow • Liverpool • Bratislava • Gomel* • Minsk HEP* • Minsk INP* • Bucharest* • IHEP • IINR • JINR • Sofia • Mainz • UCL Louvain TRIUMF • CERN • George Meson • SLAC • UC Merced • Ferrara • Florence • LNF • Naples • Perugia • Pisa • Rome I • Rome II • Turin • San Luis Potosi ~150 physics from 30 different institutions

  30. Summary of SM Theory Uncertainties CKM parameter uncertainties dominate the error budget today. BRSM(K++nn) = (8.22 ± 0.75)x1011 Present prediction has 9% error. With foreseeable improvements, it is reasonable to expect the total SM theory error ≤6%. Unmatched by any other FCNC process (K or B). 30% deviation from the SM would be a 5 signal of New Physics Lot of room for NP left by present experimental knowledge:

  31. Trigger and DAQ O(10 MHz) RICH MUV CEDAR STRAWS LKR LAV L0 1 MHz 2K 1K 2.5K 13K 8K L0 TP 200 1 MHz 1 MHz 1 MHz O(<1ms) L1 PC PC PC PC PC PC PC PC PC GbE switch EB/L2 PC PC PC PC PC PC PC PC PC PC PC PC PC PC L0 trigger CDR O(KHz) Trigger primitives

  32. 2007 data K+e2 samples Pb wall installed No Pb wall (sample analysed) Ke2 candidates: 62,170 Background: 11.9% Ke2 candidates: 59,964 Background: 8.7%

  33. Partial (40%) data set Preliminary NA62 Ke2/K2result first presented at Kaon 2009(Tsukuba, Japan, June 2009): PoS(KAON09)025, arXiv:0908.3858 RK/RK=0.64% • Significant progress since then: • Beam halo background subtraction procedure improved + other improvements data sample increased by 17% to 60K Ke2 candidates without significant change of the systematic uncertainties. • Dedicated simulations of IB radiative corrections to the Kl2 decay eliminated the corresponding systematic uncertainty. • Fine corrections for the local sources of positron identification and trigger inefficiency; fine corrections to the background estimate. Updated result presented at BEACH 2010 Perugia, Italy, June 2010): arXiv:1008.1219, accepted by Nucl. Phys. B Proc. Supp. RK/RK=0.52%

  34. Analysis of the full NA62 data set • Varying data taking conditions: • alternative K+/K– beams (for beam halo background measurement); • Pb wall during early data taking (for muonmis-ID measurement). • Reprocessing of the full physics data set completed; • Electron ID efficiency analysis completed; • All relevant calibration databases produced; • MC productions are progressing. • Updates: • more elaborate beam halo background subtraction for K– data; • measurement of BR(Ke2 SD) to address the high Ke2 background with Pb data.

  35. Summary RK • Analysis of the partial 40% data setwas completed in 2010. The corresponding publication is being reviewed by the Collaboration, and is to be submittedas CERN preprint in Dec 2010 or Jan 2011. • The preparatory work for the analysis of the whole 2007data sample (calibrations, efficiency analysis, etc.) has been • completed. • Active work on Ke2/K2measurement with the full 2007 data set: (1) improvement of beam halo background subtraction methods; (2) measurement of the Ke2 (SD) background process; (3) averaging of the partially correlated measurements. • The 2007 physics programme spans beyond Kl2() studies: precise measurements of Kl3 and rare decays are foreseen.

  36. NA48 Dismounting

  37. Synchronization Run • Preamble: Our goal remains physics data talking in 2013 and 14. • Synchronization Run in fall 2011 • Validation Test for the new common electronics boards, e.g. TEL62, TDCB. • Test of timing; synchronization of detectors and beam • Test for readout and online systems • Limitation: uses Muons (no hadron beam) and only a subset of detectors • Two main difficulty: • Advance final solutions for detectors and infrastructure, and avoid temporary patch-ups for 2011. • Manpower needs to be reinforced, especially to finalize the common electronics (TEL62, TDCB,…)

  38. NA62 2010 Achievements RK Result (40% of the 2007-2008 data) Launch of the NA62 Software Framework (C++) NA60 Dismounting NA48 Dismounting NA62 Technical Design Document STRAW Engineering Prototype & Test GTK Laser Setup Construction GTK Prototype Bump Bonded Assembly (IZM) GTK Prototype Test Beam GTK ASIC Architecture Choice LKR CREAM Market Survey RICH Vessel Design LAV A2-A3 Construction

  39. In a nutshell: NA62 in 2011 Publish the RK Result (100%sample) NA62MC & Reconstruction release NA62 Trigger Simulation GTK Submission of full size R/O chip GTK Thinning and handling of dummy wafers GTK Choice of the cooling option STRAW Module Zero Construction STRAW Finalization of F/E -- R/O Electronics LKR CREAM Prototype/Pre-series RICH Vessel Construction LAV stations 5 6 7 / IRC Construction MUV3 Installation NA62 Synchronization Run

  40. A look forward: SPS Schedule and NA62 NA62 proposes to mitigate the lack of SPS running in 2012 by planning a Synchronization run late in 2011 and to start Physics Data Taking in 2013 The synchronization run would need to take place as late as possible in 2011 (about two weeks) and would require muons in ECN3 The Collaboration needs to collect a significant data sample before another long shutdown (in addition to the 2012 one)

  41. Muon efficiency vs. threshold 3 mV threshold is well above the noise, the efficiency for muon is 100%. Electron efficiency is under study Efficiency Monte Carlo Layer 2 data Threshold (pC) 3 5 6 8 Threshold mV) 4 7

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