neutrino coherent scaering. will we see it in 2017?
TRANSCRIPT
NeutrinoCoherentsca/ering.Willweseeitin2017?
YuriEfremenko,UTKFeb15th2017
HEP&Astroseminar
TimescalesinHEP
0
0.5
1
1.5
2
2.5
3
3.5
1900 1920 1940 1960 1980 2000 2020
Proposed
Discovered
ApplicaRon Neutrinos
Higgs
CEνNS
CEνENSàCoherentElasRcNeutrinoNucleusSca/ering
Supersymmetry
NeutrinosarepopularinmanycommuniRes.
ThisisactualshotatLeadS.D.
Whatdoweknowaboutneutrinos?
I.Theydoexist
F.A.Sco/,Phys.Rev.48,391(1935)
II.TherearethreelightneutrinospeciesNν=2.984±0.008 Z0
III.Neutrinosdooscillateandthereforetheyaremassive
(observed-b
g)/
expe
cted
H
WhatwedonotKnowAboutNeutrinos?ExactmassvalueMasshierarchyAreneutrinoitsownanRparRcleHowneutrinosaffectevoluRonoftheuniverseArethereanysterileneutrinosNeutrinointerac;ons
dσdTA
= GF2
4πmA Z 1− 4sin2θW( )− N"
#$%
21−mA
TA
2Eν2
"
#&
$
%'F 2 (Q2 )
σ tot = GF2Eν
2
4πZ 1− 4sin2θW( )− N"#
$%
2F 2 (Q2 )
mA − nucleus mass
TA − kinetic energy of recoil nucleus
Eν − neutrino energy
Z − nucleus charge
N − number of neutrons in the nucleusF is nucleus form factor
Eν < 50MeV
Weinberg(Electroweek)angle
cosϑW =mW
mZ
= 0.23120 ± 0.00015
ItisfreeparameterintheStandardModel
Thereisnofundamentaltheorywhichexplainitsvalue
Itis“running”constant,itdependsonthemomentumtransfer.
CEvNSandWeinbergangle?
arXiv:1411.4088
�coh
⇠G2
f
E2
4⇡(Z(4 sin2✓
w
� 1) + N)2
Barbeau
MeasurementwithtargethavingdifferentZ/NraRoisrequired.
Aprecisiontestof𝜎isasensiRvetestofnewphysicsabovetheweakscale.SensiRvitytoahypotheRcaldarkZmediator,apossibleexplanaRonforthe(g-2)μanomaly,canbereached
witha5%measurement.
CorrecRontog-2formuonmagneRcmomentduetoa
lightmediator
COHERENT
Non-StandardInteracRonsofNeutrinos:newinterac>onspecifictoν’s
LNSI⇤H = �GF⇤
2
�
q=u,d�,⇥=e,µ,⇤
[⇥̄��µ(1� �5)⇥⇥ ]⇥ (⇤qL�⇥ [q̄�µ(1� �5)q] + ⇤qR
�⇥ [q̄�µ(1 + �5)q])
J.HighEnergyPhys.03(2003)011
WhytoSearchforCoherent𝛎-NucleusSca/ering?
J. Barranco et al., JHEP0512:021, 2005 K. Scholberg, Phys.Rev.D73:033005, 2006
Non-Standard𝛎InteracRons(Supersummetry,neutrinomass
models)canimpactthecross-secRondifferentlyfordifferentnuclei
COHERENT
DUNE
–measuringthecharge-parity(CP)violaRngphaseCP,
–determiningtheneutrinomassordering(thesignofΔm212)
–precisiontestsofthethree-flavorneutrinooscillaRonparadigm
~1billionproject
arXiv:1604.05772v1
IfyouallowforNSItoexist,can’ttelltheneutrinomassorderingwithoutconstrainsonNSI
NOw/noNSI...
...looksjustlikeIOw/NSI
NewPaperbyPilaretal.
andmoreintherecentliterature...
µBµB
Ne target
NeutrinomagneRcmomentd�
dE=
⇡↵2µ2⌫Z
2
m2e
✓1� E/k
E+
E
4k2
◆Signatureisdistor>onatlowrecoilenergyE
èrequires low energy threshold
See also Kosmas et al., arXiv:1505.03202
PresentLimit
PhysicsforFutureExpansions
A. Drukier & L. Stodolsky, PRD 30 (84) 2295
• Thecross-secRonissensiRvetothemagnitudeoftheNeutrinoMagneRcMoment(Supersymmetry,LargeExtraDimensions,RightHandedWeakCurrents).
• COHERENTmaybethefirstexperimenttoobservetheEffecRveNeutrinoChargeRadius.
• TheneutrondistribuRonwithinthenucleusimpactstherecoilenergydependentcross-secRon(FormFactor)
K. Patton, et al., PRC 86, 024216
A. C. Dodd, et al., PLB 266 (91), 434
A. J. Anderson et al., PRD 86 013004 (2012)
J. Papavassiliou, J.Bernabeu, M. Passera, HEP-EPS 2005, Lisbon, arXiv:hep-ph/0512029
16
Thedevelopmentofacoherentneutrinosca/eringdetecRoncapabilityprovidesthemostnaturalwaytoexplorethesterile
neutrinosector.
WhytoSearchforCoherent𝛎-NucleusSca/ering?
J.R. Wilson, PRL 32 (74) 849
Barbeau 17
LargeeffectonSupernovaedynamics.Weshouldmeasureittovalidatethemodels
WhytoSearchforCoherent𝛎-NucleusSca/ering?
CDMS II Ge (2009)
Xenon100 (2012)
CoGeNT (2012)
CDMS Si (2013)
EDELWEISS (2011)
DAMA SIMPLE (2012)
ZEPLIN-III (2012) COUPP (2012)
LUX (2013)
Plot: E. Figueroa-Feliciano
Barbeau 18
ItwillbeirreduciblebackgroundforDarkMa/erexperiments
(Stodolsky) 10kpc,10tonà100events
~1Keventspertonperyear.
+ =
1.E-441.E-431.E-421.E-411.E-401.E-391.E-381.E-37
0 10 20 30 40 50
1.E-05
1.E-04
1.E-03
1.E-02
1.E-01
1.E+00
1.E+01
0 10 20 30 40 50
CrossSecRonisLarge!!!
Eν,MeV
σ,cm2
ν+Xe
ν+He
ν+He
ν+Xe
IBD
Eν,MeV
ButtheSignalisHardtoDetect
Erecoils,MeV
NeutrinoCoherentSca/eringdetecRon
A
Z0
A
StoppedPionFaciliRes
NuclearReactors
1.3MWDistance~20mEν~40MeVPulsedbeam2*1015ν/sec
3GW–1MWDistance~20mEν~4MeV
ConRnuesoperaRon6*1020ν/sec
!
RaceforthefirstCEvNSdetecRon
Experiment NeutrinoSource
EffecRveEv Distance Technology Target Mass
RicochetatChooz Chooz2x4.3GW ~4MeV 355m Bolometer Ge,Zn 5+5kg
RicochetatMIT MITR5MW ~4MeV 4m Bolometer Ge,Zn 5+5kg
MINER TexasA&M1MW ~4MeV 2m IonizaRon Ge,Si ~kg
CONNIE Angra3.8GW ~4MeV 30m CCD Si 0.1kg
RED-100 Kalinin3.2GW ~4MeV 25m 2phase Xe 100kg
vGeN Kalinin3.2GW ~4MeV 10m IonizaRon Ge ~5kg
COHERENT SNS(DAR) ~40MeV 20-30m IonizaRon CsI,Ar,Ge 14,30,10kg
Inredshownexperimentswhicharetakingdata
Si Ge ArXe
He
25
MyCar
SNS layout
26
1.3GeVprotonlinearacceleratorAccumulatorring
Maintarget
Strippingfoil
ν⋅⋅⋅ x ~1000 ⋅⋅⋅
LINAC:
Accumulator Ring:
Repeat 60/sec.
Mercury target
27
MercuryInventory–20tFlowrate340kg/sec
Vmax3.5m/secTin600CTout900C
Mercury lasts the entire 40 year lifetime of SNS no change is required
Stainless steel vessel should be replaced periodically
Some Details of Interaction in the Target
for 1.3 GeV protons
AverageinteracRonenergyis~1.1GeV AverageinteracRondepth~11cm
ProtoninteractsnearthefrontpartofthetargetTheybreakdownMercurynucleusandproducepions.
Decay In Flight or Decay At Rest
29
200MeV/cpionsrangeinmercuryis~5cm
Veryfewpionshaveachancetodecaybeforecomingtotherest
PionSpectra
BecauseofthebulkMercurytarget,SNSisamostlyDecayAtRestfacility!!
NeutrinoProducRonatSNS
Hg
π+
π-~99%
µ+
e+
pνµ
νµ
νe
τ ≈ 26 nsec
τ ≈ 2200 nsec
Neutrons
CAPTURE
DAR +DIF
νµ
~1%DIF
µ-
CAPTURE
νµ
~94%
νµ
νe
τ < 2200 nsec e-
νµ
Neutrino Production at the SNS
31
SNSISIS,LANSCE
ThegoodapproximaRonis
Nπ+/proton=0.14*E(GeV)-0.05ForE~0.8-1.5GeV
Eachπ+generates
electronneutrinoandmuonneutrinoandanRneutrino
!
Target MaxRecoil(keV) CrosssecRon10-42cm2 Threshold,keVnr Nevents,year
He 483 13.8 10 134
C 161 125 10 370
Ne 96 609 10 980
Si 69 688 0.1 990
Ar 48 1700 10 1080
Ge 27 5830 3 2560
I 15 19400 10 732
Xe 15 22300 1 5970
1MWspallaRonsource,15mfromthetarget,100kgdetector,prompt30MeVneutrinos,eventratesforCEvNS
CollaboraRontomakethefirstdetecRonoftheNeutrinoNeutralCurrentCoherentsca/eringattheSNS
n
ThereareMulRpleFastNeutronSourcesinsidetheTargetbuilding.
IntermediateNeutronswithenergymorethan50keVcanproducenuclearrecoils.Thisismajorbackground!!!!
!
35
*103cm
MainTarget
ProtonTransportBeam
“Out-of-beam”events,primarily
muons.
“In-Beam”events,considerablymoreneutronevents(and16xless“liveRme”)
Startedin2013
Pos5islocaRonwithverylowneutronsflux.Needshieldingagainstgammasandcosmic.NowitiscalledNeutrinoAlley
NeutrinoAlleyattheSNS
BasementlocaRonisfarawayfromNeutronbeamLines.ExtraprotecRonfromcosmicrays
Neverbeenmeasured.ThereareonlytheoreRcalcalculaRons
Thisreac>ononLeadisusedbyHALOexperimentintheSNOlab,towatchforsupernovae.
In
InthisarRcleauthorsbelievethatJ.Davisiswrongbya~6ordersofmagnitude.
authorexplainsDAMAseasonalmodulaRonsbysolarneutrinoinducedinteracRonsinthe
DAMAshielding
FirstStepIstoMeasureNeutrinoInducedNeutronsNINs
(FirstNeutrinoExperimentattheSNS)
LiquidScinRllatordetectorsinsideLead,Poly,Cd,Watershieldwithmuonveto
Onthenextdaya{erwefinishedinstallaRonSNSgotwaterleakinthe
accelerator,thentargetfailed.
TookgoodstaRsRcsduring2014-2015
Totalof175daysof“beam”
Havenotseenanythingabovebackground.Thisisagoodnewsforus!!!!
NeutrinoInducedNeutrons–NINsSecondAFempt
• LiquidscinRllatordetectorswithneutrongammaseparaRoncapability• TwosetswithLead(1ton)andIron(700kg)targets.• NeutrondetecRonEfficiency~10%Leadtargetàalmostayearofdataaccumulated,IrontargetdatatakingisstarRngnow.
ThreeDetectorTechnologyforCOHERENTPhaseI
CsI LAr HPGe
Target TargetMass MaxRecoil(keV)
CrosssecRon10-42cm2
Threshold,keVnr
Nevents,year
Ge ~10kg 27 5830 3 280
I 14kg 15 19400 10 170
Ar 30kg 15 1700 10 250
Neutronswithenergy>50keVcanproducesimilarrecoilsàmajorbackground
CsIdetector–MajorPlayerisUCh14.5kgultrapureCsIcrystalinsidecomprehensiveshielding
andacRvemuonvetosystem
LiquidArgonDetector–MajorplayerisUISpecs:• LAr
• ~30kgfiducialvolume
• 2×HamamatsuR5912-02-MOD8”PMTs• 8‘’borosilicateglasswindow• Standardbialkaliphotocathode(K2CsSb)• 14dynodes• QE:18%@400nm
• WLS-Tetraphenylbutadiene(TPB)
• Cryomechcryocooler–90Wt• PT90single-stagepulse-tubecoldhead• compressor:CP950
LArConstrucRon• AcryliccylindersanddiscscoatedbyTPB
• 3xcylinderbyairbrush• 2xdiskbyevapora>onatORNL
• ThethicknessoftheTPBisop>mal~0.2mg/cm^2
• Teflonwrap
• Detectorwasassembledatcleanroomatthestagingarea
LArat“Neutrinoalley”
LArfillingline
Liquefier
CENNS-10Pumpingcart
Gasrack
Cryocompressor
SCrackDAQrack
LArdetectorfilling
• ~9daysforfilling• 160lbsLAr
12/12/2016
Shieldingdesignandstatus
Water-9in(polytank)• Onplace• Notenoughwateronthetop
(~1”)->waterbags(~5”)
Copper–1/2in• Done,readyfor
installa>on
Lead-4in(2layersofchevronbricks)• Needseismicanalysis
ProjectedeventratesforLAr
ArrayofGermaniumDetectors-MajorPlayerisNC
Upto10kgofGedetectorsusingcommonLNpoolSurroundedbycomprehensiveshielding
Dewarfabrica>onnearingcomple>on.
ExpecteddeliverySpring2017.
GearrayconstrucRon
OtherpotenRalneutrinophysicsattheSNS
NeutrinooscillaRons–TestoftheLSNDclaim
SearchforSterileNeutrinos
NeutrinoMagneRcmoment
MeasurementofNeutrinoSpectrafromMuonDecay
ChargeCurrentCrosssecRonMeasurements
Core-collapsesupernovae
SN 1987a Anglo-Australian Observatory
• Destruction of massive star initiated by the Fe core collapse – 1053 ergs of energy released – 99% carried by neutrinos – A few happen every century in our Galaxy, but the last one
observed was over 300 years ago
• Dominant contributor to Galactic nucleosynthesis
• Neutrinos and the weak interaction play a crucial role in the mechanism, which is not not well understood
SN neutrino spectra, 0.1 s post-bounce
Nuclear reactors Eν<10 MeV
Too cold
H.E. “accelerators” Eν >100 MeV
Too hot
Justright
Supernovaneutrinoobserva;ons• Measurement of the neutrino energy
spectra and time distribution from a Galactic supernova would provide a wealth of information on the conditions in supernovae, neutrino oscillations, etc.
Bruenn et al. (2004)
NewgeneraRonofLargemassDarkma/erexperimentscouldbesensiRvetotheGalacRcSupernovae.
Needtounderstandsignalindetectors.LowenergyneutrinointeracRonareneverbeenmeasured!!!
!
SN
SNS
Conclusion
SNSistheworldmostpowerfulpulsedneutrinosource
NeutrinoEnergyrangeattheSNSisjustrightforthesearchofCEvNS
ThereiscomprehensiveandexciRngneutrinoprogramattheSNS
PresentlyCOHERENTcollaboraRonisengageindeploymentofthe
firstgeneraRonofdetectorstosee“FirstLight”
Therearemanyideasandforthewhattodoa{erthefirstobservaRonofSEvNS