Super Fine-Grained Detector for improved neutrino interaction measurements in T2K

Supe Fine-G ainedDe ec o  o 
imp o edneu inoin e ac ion
measu emen sinT2K
Wa a uOkinaga o T2KSupe FGDg oup
Neu inoTelescopes2025
T2Kexpe imen 2
•ALongbaselineneu inooscilla ionexpe imen inJapan
•beam omJ-PARC,measu eda anea and a de ec o 
•Fa de ec o :Supe -Kamiokande
•Measu esdisappea anceandappea ance
•CPconse a ionwas ejec eda a90%C.L.
νμ/ ¯νμ
νμ/ ¯νμνe/ ¯νe
Supe -Kamiokande(SK) J-PARCMainRing
Nea de ec o s
TalkbySophieKing
Nea de ec o ND280
•FGDs(scin illa o  acke s)su oundedbyTPCsandECals
•Cons ains heneu inofluxandin e ac ionunce ain ies
•Limi a ions:
•Lowsensi i i y o sho  angepa icles(mainlyp o ons)
•Difficul  o ackpa icleswi hla gesca e ingangle
•Anupg adewasdone o u he cons ainunce ain ies
3
w/oND280
w/ND280
1 ingmuon
ν
13.0%
3.0%
ν
12.0%
4.0%
1 ingelec on
ν
13.8%
4.7%
ν
12.7%
5.9%


E en numbe unce ain ya SK
TheEu opeanPhysicalJou nalC,83(9)
•Replaced heups eampa o ND280wi h h eenewsub-de ec o s
•Supe FGD( his alk)
•2 onac i eneu ino a ge madeo scin illa o cubes
•High-angleTPC(TalkbyMa eoFel e,S e anoLe o a o)
•Measu epa icleswi hla gesca e ingangle
•Time-o -Fligh de ec o s
•Timingin o ma ion o ejec backg ounds
•150ps iming esolu ion
ND280upg ade 4
Exis ingTPC
TalkbyGioeleReina
FGD oSupe FGD 5
Scin illa o cube
WLS ibe s
192 182
56
•ClassicFGD(184x1x1cm3scin illa o ba s)
•Readou  om2di ec ions
•Requi es6hi s o  ack econs uc ion( ange>6cm)
•Canno  ackpa iclespa allel o heba s
•Supe FGD(1cm3scin illa o cubes,192x182x56)
•Readou o 2Dx3di ec ions(X,Y,andZplanes)
•3hi sneeded o  acking
•4πaccep ance
•To al55,888channels

Scin illa o cubesandWLS ibe s
•2millionscin illa o cubesmadebyinjec ionmolding
•Reflec inglaye s o medbychemicale ching
•Manu ac u edbyUNIPLASTCo.
•3holes oinse wa eleng hshi ing(WLS)fibe s
•P opaga e heligh  opho o-senso s
•Y11p oducedbyKu a ay
6
1cm
Pho o-senso sandde ec o box
•Hamama suMul i-PixelPho onCoun e (S13360-1325PE)
•8x8MPPCsa emoun edonap in edci cui boa d
•Afi mye ligh boxwasdesigned ohold hecubes
7
1.3mm
MPPC
MPPCsmoun edonaPCBDe ec o box
A ach
LEDcalib a ionmodules
•LEDcalib a ionmodulesa ea achedon heopposi esideo  hebox
•Injec ligh  om heopposi esideo  heWLSfibe s o heMPPCs
•Ase o ligh guidepla e(LGP)anddiffuse p o idesuni o mligh
8
Cubes
Boxwall
ToMPPCs
No ch
•F on -EndBoa ds(FEBs)digi ize hesignal om heMPPCs
•8CITIROCchipsmoun edoneachFEB
•Op icalConcen a o Boa ds(OCBs)builde en sandsend oaDAQPC
•AMas e ClockBoa d(MCB)p o idesclock imingand igge
Elec onics 9
MPPC-PCB
FEB
OCB
MCB
LEDd i e
DAQPC
x881(64ch/PCB) x221(4PCB/FEB) x16(14FEB/OCB)
LEDmodule
Clock, igge
Synch onized
da a
LED igge LEDsignal
Analog
signal Digi al
da a
Muonandp o onanalysis
•A4πaccep ancewasachie edwi hSupe FGD
•Sys ema ice o s omla geanglee en scanbe educed.
•Aclea p o onB aggpeakwasseenin ealda a.
•P o onscanbe agged o e en ca ego iza ion
16
T2Kwo kinp og ess

Neu onanalysis
•Supe FGDiscapableo measu ing
•Neu onsa ede ec edwi hsca e edp o ons
•Theneu onene gy(=speed)canbecalcula ed om he ime-o -fligh
17
T2Kwo kinp og ess
¯νμ+p→μ++n
Aneu one en candida e
TalkbyAsi S i as a a
Elec onneu inoanalysis
•c oss-sec ione o iscons ainedonlybya heo e icalp edic ion
•Aiming omeasu ec osssec ionwi hSupe FGD
•~1%o  hebeamcomponen 
•Elec on/gammacanbedis inguishedinSupe FGD
•Measu e heene gydeposi a  hee+e-o e lap egion
18
T2Kwo kinp og ess
Con e sionpoin
νe
e en candida e
νe
e en candida e
γ
νe
Summa y
•T2Kaims ofindCP iola ionin helep onsec o 
•Weupg aded henea de ec o  o u he cons ainunce ain ies
•Anewneu ino a ge ,Supe FGDwasins alled
•Composedo 1cm3scin illa o cubes
•Capableo  ackingpa iclesin3D
•Lowene gyp o ons,high-anglemuonscanbeanalyzed
•Beamda awas akeninJune2024
•S ay uned o ou fi s physics esul s!
19
Backup
CP
δ
3−2−1−0 1 2 3
2
χ∆
0
5
10
15
20
25
No mal o de ing
In e ed o de ing
CLσ1
90% CL
CLσ2
CLσ3
CLσ1
90% CL
CLσ2
CLσ3
T2Kla es  esul andp ospec
•CPconse a ionisexcludeda a90%C.L.
•S a is icale o is hedominan unce ain y.
•Nowinc easing hebeampowe (up o1.3MW)
•Sys ema ice o willbedominan ina ewyea s
•ND280wasupg aded o u he  educe hein e ac ionunce ain y
21
(δCP = 0, π)
dis ibu ion o (Bes fi )
δCP =−π/2
δCP
Δχ2
Achie ed800kW

Supe FGDdynamic ange
•Th eecha ge eadou s:Highgain,lowgain, ime-o e - h eshold
•Co e 3.5pe o~2000pe
•HGcalib a edwi hLEDda a
•LGandToTa ec osscalib a edin heo e lap egion
•Cosmicandbeamda aa eused
22
T2Kwo kinp og ess