Tsuyoshi Nakaya (Kyoto Univ.)

Transcription

1 TAUP Seattle September 8, 2003 Tsuyoshi Nakaya (Kyoto Univ.) Thanks to the Super-K, K2K, JHFν, UNO, LANNDD members. Special thanks to M. Shiozawa (ICRR, U. of Tokyo) and K. Kobayashi (SUNY at Stony Brook)

2 . Introduction (SUSY) SU(5), SO(0),E 6 SU(3) C SU(2) L U() Y GUT quark + lepton Proton Decay 2

3 No Evidence of Proton Decay so far No Direct Evidence of GUT however, Indications or Hints of GUT Running coupling constants may be unified with SUSY (Precise LEP data) Small but finite neutrino mass (neutrino oscillation) ν Discovery of Proton Decay may be just at the corner. 3

4 Dimension 6 operators: qqql (Gauge-Boson Mediated Decay) M 2 p u e 4 (34 35) M u Y τ 0 years 6 d d d π 0 p 0 GeV ~0 ~35 years Dimension 5 operators in SUSY models: M p u u d w ~ q ~ q ~ H ~ C minimal SU(5) ν s d minimal SUSY SU(5) Κ + τ p (5 6) M m SUSY 6 0 ~ years Super-K TeV ( q ~ q ~ q i j years k l SUSY SO(0) l + ) partial nucleon life time (year) 4

5 aim: τ p 0 35 years 0 35 protons (~300 ktons H 2 O) LANNDD UNO The MEMPHYS project: The Project of a Megaton (Y. Suzuki, NOON2000) ( Megaton Mass Physics) UNO type detector at Frejus: ~Mton Proton Decay detector (Luigi Mosca, TAUP2003) LANNDD 2 in Japan, USA and Europe. (David Cline, TAUP2003) 6

6 aim: τ p 0 35 years 0 35 protons (~300 ktons H 2 O) LANNDD UNO The MEMPHYS project: The Project of a Megaton (Y. Suzuki, NOON2000) ( Megaton Mass Physics) UNO type detector at Frejus: ~Mton Proton Decay detector (Luigi Mosca, TAUP2003) LANNDD 2 in Japan, USA and Europe. (David Cline, TAUP2003) 6

7 aim: τ p 0 35 years 0 35 protons (~300 ktons H 2 O) LANNDD UNO The MEMPHYS project: The Project of a Megaton (Y. Suzuki, NOON2000) ( Megaton Mass Physics) UNO type detector at Frejus: ~Mton Proton Decay detector (Luigi Mosca, TAUP2003) LANNDD 2 in Japan, USA and Europe. (David Cline, TAUP2003) 6

8 aim: τ p 0 35 years 0 35 protons (~300 ktons H 2 O) LANNDD UNO The MEMPHYS project: The Project of a Megaton (Y. Suzuki, NOON2000) ( Megaton Mass Physics) UNO type detector at Frejus: ~Mton Proton Decay detector in Japan, USA and Europe. (Luigi Mosca, TAUP2003) LANNDD 2 (David Cline, TAUP2003) 6

9 aim: τ p 0 35 years 0 35 protons (~300 ktons H 2 O) LANNDD UNO The MEMPHYS project: The Project of a Megaton (Y. Suzuki, NOON2000) ( Megaton Mass Physics) UNO type detector at Frejus: ~Mton Proton Decay detector LANNDD 2 in Japan, USA and Europe. (Luigi Mosca, TAUP2003) (David Cline, TAUP2003) 6

10 aim: τ p 0 35 years 0 35 protons (~300 ktons H 2 O) LANNDD UNO The MEMPHYS project: The Project of a Megaton (Y. Suzuki, NOON2000) ( Megaton Mass Physics) UNO type detector at Frejus: ~Mton Proton Decay detector (Luigi Mosca, TAUP2003) LANNDD 2 in Japan, USA and Europe. (David Cline, TAUP2003) 6

11 Unusual Nucleon Decay (Baryon number Lepton number) Nucleon Disappearance (Extra Dimensions with TeV gravity.) It is also important to look for p (n) invisible state For these modes, a gigantic scintillator detector may work better (KamLAND( and ) (Bob Svoboda, TAUP2003) 7

12 2. Review of proton decay experiments Water Cherenkov Detector (H 2 O) Super-Kamiokande for UNO, Hyper-K, and TITANIC Fine Grained Detector (Fe and Ar) Soudan2 for ICARUS and LANNDD 8

13 Fermi motion of parent nucleons in 6 O Nuclear potential Nucleon-nucleon correlation in 6 O Number of Events H 2 O O(p-state) O(s-state) uncorrelated Correlated (traditional) decay decay Entries correlated decay p+n e + +π 0 +N (0% of decays in 6 O) Reconstructed Mass of e + π 0 (MeV/c 2 ) H ~90% 9

14 Α π 0 from the proton decay may be interacted in a nucleus scattering absorption charged exchange e πp 0 n n p p p n n p p n p p n n n π + Probability ~ 50% 0

15 2.3 Super-Kamiokande 489 days data (92kt yr) Ring Imaging Water Cherenkov Detector 39 m 4 m C Scientific American 000 m underground 50kton (22.5kton fid.),46 20 inch PMTs,885 anti-counter PMTs

16 p eπ 0 Search MC Events NUM RUN SUBRUN EVENT 45 DATE 97-Jun-7 TIME 2:35:52 TOT PE: MAX PE: 68.2 e + γ γ γ Colour : Time Radius : Charge 2

17 2 or 3 rings All rings are electron-like no decay electron 85<m π <85MeV/c 2 (3-ring) 800<m p <050MeV/c 2 p total < 250MeV/c Efficiency = 40% Total momentum (MeV/c) Super-Kamiokande Preliminary p e + π 0 p e + π 0 MC Invariant proton mass (MeV/c 2 )

18 Total momentum (MeV/c) DATA (~4 years: 9.6 kt year) Super-Kamiokande Preliminary 489 days data Invariant proton mass (MeV/c 2 ) p eπ 0 Result 0 events τ p /BR(p e + π 0 ) > years (90% CL) Total momentum (MeV/c) Atmospheric ν MC (2,250 kt year : DATA 25) Super-Kamiokande Preliminary 00 years atmν MC Invariant proton mass (MeV/c 2 ) w/ 0.3 expected Background events Background: ν e N e ± π ± N, π ± N π 0 N (in the oxygen) 4

19 DATA and MC Comparison 6 4 Super-Kamiokande Preliminary days total momentum (MeV/c) L L (938,200) total mass (MeV/c 2 ) P total total momentum (MeV/c) 0 Super-Kamiokande Preliminary days MC:p eπ 0 Super-Kamiokande Preliminary days L in mass v.s. momentum plot distance L in mass v.s. momentum plot 0 MC:p eπ 0 (*) There is a measurement of the p µπ 0 background by K2K (Mine, TAUP2003) total invariant mass M P (MeV/c 2 ) 5

20 Other Gauge Boson Mediated Decays (90% C.L.) Total momentum (MeV/c) Total momentum (MeV/c) Super-Kamiokande Preliminary 489 days data p µ + π Invariant proton mass (MeV/c 2 ) τ/br > years Super-Kamiokande Preliminary 489 days data p e + ρ 0,ρ ππ Invariant proton mass (MeV/c 2 ) τ/br > years Total momentum (MeV/c) Total momentum (MeV/c) Super-Kamiokande Preliminary 489 days data p e + η 0,η γγ Invariant proton mass (MeV/c 2 ) τ/br > years Super-Kamiokande Preliminary 489 days data p e + ω 0,ω π 0 γ Invariant proton mass (MeV/c 2 ) τ/br > years 6

21 p νk + Search e + ν e MC Events γ (6.3MeV) ν µ ν K + µ + (236ΜeV/c) γ µ + 6 O ν µ γ µ + e + t 2ns 2.2µs 2,200ns 7

22 A Novel Idea: Prompt γ tag ν 6 O K + 5 N * γ A proton in 6 O decays (or disappears) 4% 6.3MeV γ-ray generates This propmt γ events will be measured at K2K by NC elastic scattering (ν+ 6 O ν+ 5 N * +p). 8

23 K + µν promptγ search -ring µ-like 25<p µ <260MeV/c Decay electron No proton ring 7<N γhit <60 (prompt γ) number of event data p νk + MC atmν MC Efficiency = 8.6% τ p /BR(p νk + ) >. x0 33 years (90% CL) w/ 0.7 expected Background events N γhit N γhit 9

24 number of event Other channels in p νk + () K + µν, µ eνν w/o γ tag (2) K + π + π 0, π + ( µν) eνν K + µν spectrum search data atmν+p νk + MC (90%CL) atmνmc µ momentum(mev/c) p µ (MeV/c) τp/br(p νk + ) >0.42x0 33 years Light Yield from not π 0,π Q res (PE) 50 Q res (PE) K + π + π 0 search p νk + MC Q +(PE) π K + π + π 0 search MC: K + π + π 0 DATA data Light Yield from π Q π +(PE) τp/br(p νk + ) >0.79x0 33 years Combined: τp/br(p νk + ) > 2.2 x 0 33 years (90% CL) 20

25 Other SUSY GUT Decays (90% C.L.) () n νk 0,K 0 ππ (2) p e + K 0,K 0 ππ (3) p µ + K 0,K 0 ππ K 0 momentum(mev/c) n νk 0, K 0 s π 0 π 0 search p e + K 0, K 0 s π 0 π 0 search p µ + K 0, K 0 s π 0 π 0 search K s π 0 π 0 K s π 0 π 0 K s π 0 π 0 data total momentum(mev/c) data total momentum(mev/c) data K 0 mass(mev/c 2 ) total mass(mev/c 2 ) total mass(mev/c 2 ) τ/br > years τ/br > years τ/br > years 2

26 Summary of Super-K K nucleon decay searches Summary of Nucleon Decay Searches mode exposure εb m observed B.G. τ/b limit (kt yr) (%) event (0 32 yrs) p e + + π p µ + + π p e + + η p µ + + η n ν + η p e + + ρ p e + + ω p e + + γ p µ + + γ p ν + K K + νµ + (spectrum) prompt γ + µ K + π + π n ν + K K 0 π 0 π K 0 π + π p e + + K K 0 π 0 π K 0 π + π - 2-ring ring p µ + + K K 0 π 0 π K 0 π + π - 2-ring ring

27 2.4 Soudan2 design for p νk + and multi-particles decays x224 (0.96kton) 2.7m Fine-Grained Tracking Calorimeter Detector Track resolution : 0.8 cm (X,Y) :.0 cm (Z) Trigger threshold (50 %) 75MeV for : 00MeV for e Energy resolution : E/E = 7.0/E / % e, = 8 % Partile ID : 95% 95% (60%) >400 (40) MeV e drift tube mm m m 4.7mm 23

28 p K +, K + + X TOP VIEW K + + e + Z SIDE VIEW FRONT VIEW 2 charged tracks (no proton) K range < 50 cm 28 < range < 58 cm decay electron ( 60 %) B(K + + ) = 9.0% 3.56 kt yr exposure Y Y observed candidate = exp d BG = 0.2 (atm )+0.9(rock) Z X 24

29 p K +, K + π + π - X + TOP VIEW K + 2 tracks and 2 showers K range < 50 cm 00 < M K < 660 MeV/c 2 80 < P + < 400 MeV/c 40 < P < 390 MeV/c 0 < M < 290 MeV/c 2 B(K ) = 5.5% 0 2 Z SIDE VIEW FRONT VIEW 3.56 kt yr exposure observed candidate = 0 exp d BG =.05 (atm )+0.09(rock Y Z Y X combined limit p /B(p K + ) > years (90% CL) 25

30 p νk + for Soudan2 and Super-K Exposure (Kton( Kton٠year ) Efficiency for K + µ + ν (K + π + π 0 ) #Observed Events for K + µ + ν (K + π + π 0 ) Expected Background 90%CL limit (years) Soudan (5.5) (0) 0.4 (.4) Super-K (6.0) 0 (0) 0.7 (0.6)

31 Nucleon Decay Searches in Soudan2 mode exposure εb m observed B.G. τ/b limit (kt yr) (%) event (0 32 yrs) p ν + K K + νµ K + π + π p µ + K 0 s K 0 s π + π <0.2 K 0 s π 0 π p e + K 0 s 4.4 K 0 s π + π K 0 s π 0 π p µ + K 0 l p e + K 0 l p µ + K 0 (K 0 l+k 0 s) <.2.2 p e + K 0 (K 0 l+k 0 s) n ν + K 0 s K 0 s π + π K 0 s π 0 π 0 3-shower shower n ν + K p µ + + η η γγ η π 0 π 0 π p e + + η η γγ η π 0 π 0 π n ν + η η γγ η π 0 π 0 π n ν + π p ν + π

32 Other Nucleon Decays Model-Independent limit for nucleon decay p > years (90% CL) study Xe isotopes of years old n ννν (Kamiokande) tagging nuclear γ (9MeV) from the residual nucleus /BR(n ννν) > years (90% CL) p invisible (SNO data, PLB 553 (2003) 35-40) tagging residual neutron /BR(p invisible) > years (90% CL) p n D 2 O A neutron NC signal 28

33 3. Future Experiments Several Proposals for the Water Cherenkov detectors. Hyper-Kamiokande (Japan): 540 ktons UNO (USA): 440 ktons TITANIC (Japan): >~,000 tons MEMPHYS (France): ~,000 tons Great success of Super-K K convinces people that the larger Water Cherenkov detector has an excellent sensitivity for the proton decay. All detectors have a common base of the design. I will show the study of Hyper-K K as a reference. 29

34 Site Candidiate and Construction Schedule Hyper-Kamiokande KAMIOKA SK UNO Under Survey of the site: Homestake WIPP ~0km MEMPHYS Frejus HK It takes about ~0 years for the construction after getting the approval of the project. (cost ~$500M??) ~20X? 30

35 Partial Lifetime (years) p e + π 0 sensitivity (90% CL) Standard momentum cut (<250MeV/c) Efficiency = 43% BG=3events/Mt٠yr HK 20 yr sensitivity for p eπ 0 (90% CL) efficiency=43% BG 3ev/Mtyr SK current limit (90% CL) 79.3ktyr, 5.0 x 0 33 yrs Super-K limit Hyper-K 20 years Exposure (kton year) Exposure (kton٠year) Partial Lifetime (years) Tight momentum cut (<00MeV/c) Efficiency = 7% BG=0.5events/Mt٠yr HK 20 yr sensitivity for p eπ 0 (90% CL) efficiency=7% High sensitivity BG 0.5ev/Mtyr for free proton Hyper-K 20 years SK current limit (90% CL) 79.3ktyr, Super-K 5.0 x limit 0 33 yrs 0 4 Exposure (kton٠year) Exposure (kton year) /BR > yr (Hyper-K 20yrs, 90%CL) 3

36 p νk + sensitivity (90% CL) 0 37 sensitivity for p νk + (90% CL) 0 36 Partial Lifetime (years) HK 20 yr SK current limit(90% CL) 79.3ktyr.6 x 0 33 yrs combined sensitivity π + π 0 prompt γ µ spectrum Exposure (kton year) Exposure (kton٠year) /BR > yr (Hyper-K 20yrs, 90%CL) 32

37 Feasibility of the construction of the huge Liquid Ar detector???? Proposal for the Fine tracking calorimeter detectors. LANNDD: Lq. Ar TPC 4.5 LANNDD No nuclear reinteractions Exposure: 300 kton year Efficiency (%) 42 p e + π p (years) Efficiency (%) 85 p K + p (years) Nuclear reinteractions (FLUKA) LANNDD Exposure: 000 kton year Efficiency (%) p e + π p (years) Efficiency (%) p K + p (years) No nuclear reinteractions Nuclear reinteractions (FLUKA)

38 µ-lanndd (active volume ~50L) Mini-LANNDD (~440ton) 34

39 4. Additional Physics Potential An Ultimate Neutrino Detector Super ν beam Hyper-K has a beam from JHF (J-PARC). The BNL very long baseline ν experiment assumes the UNO type of the detector. MEMPHYS plans to have a beam from CERN-SPL and a β-beam. Atmospheric ν Solar ν Supernova ν Supernova Relic ν 35

40 CP sensitivity (3σ) w/ Super-ν beam JHF-HK CPV Sensitivity sin 2 2θ CHOOZ excluded sin 2 2θ 3 <0.2@ m 32 ~3x0-3 ev no BG 0.04 signal stat only 0.02 stat+2%syst. stat+5%syst. (signal+bg) stat only stat+0%syst. JHF 3σ discovery sinδ 3σ CP sensitivity : δ >20 o for sin 2 2θ 3 >0.0 with 2% syst. 36

41 Supernova Neutrinos Supernova ν Reach ~Mpc Supernova rate will be /(0~5) years 37

42 5. Summary The discovery of the GUT is one of our dreams in physics. The Nucleon Decay is the direct evidence of the GUT. With a next generation nucleon decay detector, we explore the proton decays p e + π 0 ( >0 35 years) p ν K + ( >0 34 years) GUT SUSY-GUT A Nucleon Decay detector makes the neutrino physics more exciting. CP violation in neutrino oscillation Supernova-ν observatory High statistics atmospheric and solar neutrino experimets. 38

43 2005~200 What do you expect? An indication of θ 3 by MINOS or Super-K A candidate event of proton decay at Super-K 200~205 Discovery of θ 3 by Super-ν beam (JHF( JHFν). A few proton decay candidates. An absolute neutrino mass measurement from cosmology. >205 Discovery of CP violation in neutrino oscillation. Discovery of proton decay. 39

44 Supplement 40

45 typical p νk +, K + π + π 0 MC event Outer Detector RUN SUBRUN 0 EVENT 22 DATE 99-Nov- TIME :55:36 TOT PE: 232. MAX PE: 23.2 NHIT : 487 RunMODE:MonteCar Inner Detector Radius : Charge 4

46 Proton decays in ICARUS Excellent tracking and particle capabilities. Suitable for K events, multi-prong events. τ p > ~ x T(yr) x ε x % CL Operation in the underground will start soon 42