Search for µ eee at the High Intensity and Technology Frontier: The Mu3e Experiment

Transcription

1 Sarch for µ at th High Intnsity and Tchnology Frontir: Th Mu3 Exprimnt Johns-Hopkins Workshop Hidlbrg, July 21-23, 2014 André Schöning Physikalischs Institut, Univrsität Hidlbrg 1

2 History of LFV Dcay xprimnts Finbrg, Kabir, Winbrg (1959) from non-obsrvation of μ γ lpton flavor must b consrvd! no FCNC in lpton sctor upgrad Mu2/Comt 2

3 Discovry of Nutrino Oscillations PDG13 W W ν1ν2ν3 W l W ν1ν2ν3 μ l nutrino oscillations = FCNC (chargd) lpton flavor is NOT consrvd! LFV 3

4 History of LFV Dcay xprimnts How larg is LFV just from lpton mixing? upgrad Mu2/Comt 4

5 FCNC + Frmion Mass Pattrn μ νμ W γ ν LFV FCNC in SM quark sctor ~ FCNC in SM lpton sctor < BR(l j l k γ) ( ( ) 2 V V i ij jk Δ m2ν M mν M i 2 W ) 2 2 jk 2 W Chargd LFV is THE signatur of nw physics! 5

6 History of LFV Dcay xprimnts B(μ+ ++-) upgrad Phas I: Phas II: Mu2/Comt 6

7 LFV Muon Dcays: Exprimntal Situation μ+ + γ μ- N - N + + Au μ- μ+ μ μ+ γ - MEG (PSI) SINDRUM II (PSI) B(μ+ +γ) (2013) B(μ Au Au) (2006) + SINDRUM (PSI) B(μ+ ++-) (1988) running 7

8 LFV Muon Dcays in th SM μ+ + γ μ- N - N + + Au + - μ- μ+ μ+ ++μ+ γ + - SM: LFV loops Au branching ratios supprssd by (Δ m2ν ) m4w 8

9 LFV Muon Dcays from SUSY Loops μ+ + γ μ- N - N + + Au + - μ- μ+ μ+ ++μ+ γ + - SUSY loops Au cohrnt convrsion in nuclus fild for Q2(γ*)~0 supprssd by xtra vrtx with rspct to μ+ + γ 9

10 LFV Muon Dcays from SUSY Loops μ+ + γ μ- N - N + + Au + - μ- μ+ μ+ ++μ+ γ + - SUSY loops Au Most BSM modls (.g. SUSY) induc naturally LFV 10

11 LFV Tr Diagrams μ+ + γ μ- N - N + μ Au - μ- μ+ + μ+ γ + q q LQ μ not allowd.g. Lptoquarks xtra Z', LFV Higgs, tc. Additional BSM tr diagrams in μn N and μn 11

12 Lpton Flavor Violating Dcay: μ+ ++Exotic Physics loop diagrams tr diagram Suprsymmtry Higgs Triplt Modl Littl Higgs Modls Nw Havy Vctor bosons (Z') Ssaw Modls Extra Dimnsions (KK towrs) GUT modls (Lptoquarks) many othr modls 12

13 Exampl I: Higgs Triplt Modls M.Kakizaki t al., Phys.Ltt. B , 2003 Motivatd by Lft-Right Symmtric Modls triplt Higgs Bay, Rno, Doubl Chooz MDaya = 200 GV ν νµ ντ A= trilinar coupling (25 V) H, H++ μ + loop diagrams 4 A Br 4 M rlatd to nutrino masss ( mass pattrn) 13

14 Exampl I: Higgs Triplt Modls (cont'd) M.Kakizaki t al., Phys.Ltt. B , 2003 Motivatd by Lft-Right Symmtric Modls M = 200 GV A= trilinar coupling (25 V) 14

15 Exampl II: LFV Higgs Couplings Framwork R. Harnik, J. Kopp J, Zupan [arxiv: ] LFV LFV dcays of SM Higgs: LFV muon dcay: ~ LHC and muon dcay sarchs ar largly complmntary! 15

16 Exampl III: Low Scal Ssaw Modl Invrtd Ssaw Modl mν μ N right-handd nutrinos lptonic gaug singlts Z-pnguin M.E.Krauss t al., arxiv:1312:

17 μ+ ++- Pnguin Loop and Box Diagrams μ+ ++ γ Z μ μ photon pnguin Z - pnguin μ H μ Higgs-pnguin 17 box diagram

18 Modl Indpndnt Comparison μ μ contact IA mμ 2 Λ (1+ κ) H dipol + μ μ ν, κ J ν J 2 Λ (1+ κ) κ = paramtr Λ = common ffctiv mass scal κ 0 B(μ+ ++-) B(μ γ) + Effctiv clfv Lagrangian: L= μ + B(μ+ ++-) ~ κ B(μ γ) =

19 Modl Indpndnt Comparison μ μ contact IA μ μ B( μ ) < κ 0 κ B(μ+ ++-) B(μ γ) + + B(μ+ ++-) ~ B(μ γ) =

20 Mu3 Exprimnt Sarch for μ at PSI DPNC Gnva Univrsity Physics Institut, Univrsity Hidlbrg KIP, Univrsity Hidlbrg ZITI Mannhim, Univrsity Hidlbrg Paul Schrrr Institut Physics Institut, Univrsity Zurich Institut for Particl Physics, ETH Zurich nw collaborators KIT (Karlsruh) + Uni Mainz projct approvd in Jan 2013 Aiming for a snsitivity of BR(μ ) < (phas I) BR(μ ) < (phas II) bfor nd of this dcad 20

21 PSI Facility for Mu3 proton cyclotron Ip= MV X HiMB X NEW! Phas II (>2017): >109 muons/s Phas I (2015+): ~108 muons/s 21

22 π5 Bamlin (Phas I) MEG and Mu3 could co-xist if MEG is to b upgradd MEG muon rats of /s achivd in past rat of 108/s muons ndd to rach B( μ+ ++- ) ~ (90%CL) 22

23 PSI Facility for Mu3 proton cyclotron Ip= MV X HiMB X NEW! Phas II (>2017): >109 muons/s Phas I (2015+): ~108 muons/s 23

24 High Intnsitiy Muon Bamlin (Phas II) HiMB = High Intnsity Muon Bamlin 1011 muons Muon rats in xcss of 109 pr scond in bam phas accptanc possibl muons/s ndd to rach ultimat goal of B( μ+ ++- ) < Not bfor

25 Backgrounds Irrducibl BG: radiativ dcay with intrnal convrsion - ν ν B(μ νν) = i i 25 E i = mμ p i = 0

26 Backgrounds Irrducibl BG: radiativ dcay with intrnal convrsion - ν + missing nrgy from two nutrinos stply falling! ν B(μ+ + R.M.Djilkibav, R.V.Konoplich PRD79 (2009) ++- νν) = vry good momntum + total nrgy rsolution rquird! 26

27 Accidntal Backgrounds Ovrlays of two ordinary µ+ dcays with a (fak) lctron (-) Elctrons from: Bhabha scattring, photon convrsion, mis-rconstruction Nd xcllnt: Vrtx rsolution Timing rsolution Kinmatic rconstruction 27

28 Kinmatic Rsolution + Multipl Scattring Muon dcay: lctrons in low momntum rang p < 53 MV/c limitd hit rsolution rgim Multipl scattring is dominant! Nd thin, fast and high rsolution tracking dtctors opratd at high rat of ~ 109 particls/s 1 Θ MS P X / X0 mutipl scattring rgim 28

29 Silicon Pixl Dtctor I.Pric, P. Fischr t al., NIM A 582 (2007) 876 (ZITI Mannhim, Uni Hidlbrg) transistor logic mbddd in N-wll ( smart diod array ) Tchnology Choic High Voltag Monolithic Activ Pixl Snsors (HV-MAPS) high prcision pixls 80 x 80 μm2 can b thinnd down to ~35 μm (~ X0) low production costs (standard HV-CMOS procss, V) activ snsors hit finding + digitisation + radout triggrlss and fast radout (LVDS link intgratd) low powr: ~150 mw/cm2 29

30 Mchanical Prototyps for Pixl Trackr Ultra-thin dtctor mock-up: sandwich of 25 µm Kapton 50/100 µm glass (instad of Si) 50 mu silicon wafr Sandwich X 0.1% X0 pr layr possibl 30

31 Tst Bam Rsults for HV-MAPS MuPix4 Prototyp snsor fficincy > 99.5% 31

32 Mu3 Exprimntal Proposal 32

33 Mu3 Baslin Dsign 33

34 Mu3 Baslin Dsign 34

35 Mu3 Baslin Dsign 35

36 Mu3 Baslin Dsign 36

37 Mu3 Baslin Dsign 37

38 Mu3 Baslin Dsign 38

39 Mu3 Baslin Dsign Long cylindr! not to scal! ~180 cm ~15 cm 39

40 Mu3 Baslin Dsign Long cylindr! not to scal ~180 cm ~15 cm B = 1 Tsla 40

41 Mu3 Baslin Dsign Long cylindr! not to scal ~180 cm ~15 cm B = 1 Tsla Gomtrical accptanc ~70 % for μ+ ++- dcay 41

42 Momntum Rsolution in MS Rgim Standard spctromtr: multipl-scattring angl σ p Θ MS Ω P (linarisd) prcision rquirs larg lvr arm larg bnding angl Ω 42

43 Momntum Rsolution in MS Rgim Half turn spctromtr: σp O(Θ2MS ) P bst prcision for half turn tracks hav to masur rcurlrs 43

44 Tracking Dsign Considrations 44

45 Tracking Dsign Considrations 45

46 Tracking Dsign Considrations 46

47 Tracking Dsign Considrations 47

48 Timing 48

49 Pilup 49

50 Pixl Dtctor: Radout 20 MHz 100 muon rat muon stops/s 50 ns snapshot 50

51 Pixl: Radout Frams 50 ns 100 muon rat muon stops/s Additional Tim of Flight (ToF) dtctors rquird < 1ns 51

52 Mu3 Tim of Flight Systm not to scal ~100 ps ns Scintillating tils Scintillating fibrs 52

53 Scintillating Fibr Trackr simulation 2-3 layrs of scintillating fibrs Ø = 250 μm rad-out by silicon photomultiplis (SiPMs) and custom ASICs tim rsolution <1 ns 53

54 Invariant Mass Rsolution of Signal Phas IA: rat ~ muons/s Phas IB: rat ~ muons/s Phas II: rat ~ muons/s 54

55 Snsitivity Study Phas IA: Phas II: rat muons/s rat ~ muons/s signal signal BG BG μ νν 55

56 Snsitivity Projction /s /s /s

57 Conclusions Chargd LFV wll motivatd and almost unavoidabl in BSM modls Nw ra of high rat muon dcay xprimnts sarching for chargd LFV Svral projcts including Mu3 aiming for snsitivitis of or vn byond! Nw tchnologis (HV-MAPS, Si-Photomultiplir) ar crucial for high rat prcision xprimnts Mu3 Exprimnt vntually aiming for B(μ+ ++-) < xpctd to dlivr first rsults in a fw yars tim 57