T2K and the MAINZ Photon Beam

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1 TK and the MAINZ Photon Beam February, S. Boyd University of4 Warwick 11

2 Precis Long baseline neutrino oscillation experiment TK UK Collaboration is building an ECAL for detection We are thinking of using a tagged photon beam for calibration and reconstruction testing MAINZ fits our energy range and size/weight best The plan is around 9 (so talk may be a bit premature) This talk is a pure introduction to who we are and what we want to do. Furthur exploration will occur later.

3 Who are we? What is TK and what is it trying to do? What do TK-UK want to do? Why are we interested in the MAINZ photon beam? Schedules, etc.

4 Who are we? What is TK and what is it trying to do? What do TK-UK want to do? Why are we interested in the MAINZ photon beam? Schedules, etc.

5 Who are we? What is TK and what is it trying to do? What do TK-UK want to do? Why are we interested in the MAINZ photon beam? Schedules, etc.

6 Who are we? What is TK and what is it trying to do? What do TK-UK want to do? Why are we interested in the MAINZ photon beam? Schedules, etc.

7 Who are we? What is TK and what is it trying to do? What do TK-UK want to do? Why are we interested in the MAINZ photon beam? Schedules, etc.

8 Neutrinos have mass Neutrino flavours mix

9 Neutrino Oscillations SuperK Early Solar Neutrino Exps. 71±5 Soudan II SNO 71±5 KamLAND MACRO KK

10 Oscillation Formalism If neutrino have mass then l e,, l >= i U li i > e 1 c1 =U U= s 1 3 s 1 1 c1 c 3 s 3 i 1,,3 s 13 e i c 13 1 i s c s e Note that oscillation experiments cannot measure the absolute mass scale c13 c ij =cos ij ; s ij =sin ij P =sin sin 1.7 m ij L E

11 What do we know now? CP Violating term PMNS mixing matrix e 1 c1 3 =U U= s 1 1 =3.5o±.4 o m1 = ev e Solar s 1 1 c1 c 3 s 3 c 13 s 13 e i 1 i 1 s 3 c3 s 13 e o 3 =45 ±1 m3 =.1 1 c13 o ev 3 Atmospheric 13 1 o CP Reactor

12 What's left? More accurate determinations of already measured parameters : MINOS (to about 1%) SNO, KamLAND, Borexino(?) Next-generation long baseline and reactor experiments (TK will improve on MINOS by ~1x). Measure θ13 The sign of m3 (or m13) Lack of knowledge produces a factor of two uncertainty in Ων. The CP-violating phase δ

13 The TK (Tokai--Kamioka) Experiment

14 Who are we? 19 physicists in 11 countries Canada : TRIUMF, Alberta, British Columbia,Regina, Toronto, Victoria USA : Boston, Louisiana State, SUNY Stony Brook, UC Irvine, Colorado, Pennsylvania, Rochester, Washington, Duke France : CEA Saclay, LPNHE-INP3 Paris Italy : INFN Bari, INFN Padova, INFN Napoli, INFN Roma, Roma, Padova Naples Japan : KEK, ICRR, Hiroshima, Kobe, Kyoto, Miyagi, Nagoya, Tohoku, Tokyo Korea : Chonnam, Dongshin. Kyongpook, Sejong, Seoul, Sungkyunkwan Poland : Warsaw Russia : INR Dubna Spain : IFIC Valencia, Barcelona Switzerland : ETH Zurich, Geneva United Kingdom : Imperial College, Lancaster, Queen Mary College, Liverpool, CCLRC RAL, CCLRC Daresbury, Sheffield, Warwick

15 JPARC-SuperK or TK JPARC Accelerator Phase 1 :.75 MW 5 GeV Phase : 4. MW 99% pure February, 4 11 Far detector Super-Kamiokande Rebuild almost complete

16 February, 4 11

17 The TK Beam Quasielastic Resonance Deep Inelastic E (GeV)

18 Super-Kamiokande Far Detector

20 Super-Kamiokande µ e

21 Golden Measurement L P e ~sin 3 sin 13 sin 1.7 m E 3 Look for an excess of e in the far detector Understanding the background is the crucial issue sin 13 Conventional beams are never 1% pure Always some background in the analysis of far detector data

22 Background π p p n n

23 You need to know the cross section

24 You need to know the cross section

25 So you need to measure the cross sections Near 8m to measure beam spectrum and composition Magnet (and side MRD) B TPC Magnet (and side MRD) Scintillator based Tracking detectors ECAL

26 TK Near Detector SMURF The UA1/NOMAD magnet On loan from CERN ECAL UK Responsibility PD Tracker region

27 So you need to measure the cross section Magnet (and side MRD) B TPC p Magnet (and side MRD) p p

28 TK ECAL Responsibility of the TK-UK Institutes Downstream ECAL Basket Barrel ECAL

29 TK ECAL Responsibility of the TK-UK Institutes Scintillator based sampling calorimeter Locked in magnet X-Y bars arranged around lead sheets Read out by WLS and AMPDs with FEBs on the detector itself 1 X in barrel, 1 X downstream

30 ECAL Calibration and commissioning Calibration of sampling calorimeters is inherently difficult. Testbeams are required to set energy scale, test calibration methods before installation, assemble and test reconstruction algorithms Specific usage of this calorimeter is to measure low (on my scale) energy photons from decay. Generally done by looking at the position of the peak but there are not enough to do this from the events of interest. More crucially, we don't know the decay vertex position most of the time. Testing with a tagged photon beam is necessary to demonstrate the correctness of both calibration and photon reconstruction techniques.

31 Why Mainz? Prototype schematics (Artist's conception) meters meters MeV Photon energy spectrum from decay Weight ~ 1 ton

32 Plans and Schedule Mid 9 Scale of the tests imply that we will go through the normal approval process (e.g. Proposal, PAC vetting etc)

33 Summary TK UK Ecal is necessary to determine photon background to e appearance search To develop and test photon reconstruction algorithms and determine energy scale and resolution we would like to put calorimeter prototype in a photon beam Mainz photon beam looks like the only one at the right energy with the right infrastructure Tentatively assign mid-9 for running (but this could change depending on circumstance) Project under review for funding, so plans may change from this point of view too.

34 Oscillation II P x =1 sin sin 1.7 m Survival Probability L E m L E ~ m L/E L E L /km E /GeV m Want to put a detector here

35 What are we trying to measure? disappearance 3 sin 3 ~1%; m ~1% sin 3 m3 sin 3 ~1 % ; m 3 ~1 %

F. Retière (TRIUMF) For the T2K collaboration

F. Retière (TRIUMF) For the T2K collaboration T2K and ν e appearance First experiment since SNO attempting to measure neutrino appearance Sensitive to θ 13 m P(ν µ ν e ) sin 2 2θ 13 sin 2 θ 23 sin 2 31