Neutron Decay Correlations - int. · PDF fileNeutron Decay Correlations 1 ... and Tulin(2007)...
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Neutron Decay Correlations 1 Brad Plaster, University of Kentucky σ n e – θ e p e θ p B. Plaster QCD for New Physics at the Precision Frontier October 2, 2015 A.R. Young et al., J. Phys. G 41 (2014) 114007 S. Baessler, J.D. Bowman, S. Penttila, and D. Pocanic, J. Phys. G 41 (2014) 114003 Recent (experimental) review articles:
Transcript of Neutron Decay Correlations - int. · PDF fileNeutron Decay Correlations 1 ... and Tulin(2007)...
NeutronDecayCorrelations
1
BradPlaster,UniversityofKentucky
σ
n e–
θe
p
e
θp
B.Plaster
QCDfor NewPhysicsatthePrecisionFrontierOctober 2,2015
A.R.Youngetal.,J.Phys.G41 (2014)114007
S.Baessler, J.D.Bowman,S.Penttila,andD.Pocanic,J.Phys.G41 (2014)114003
Recent(experimental)reviewarticles:
Whatcanbemeasured?
2B.Plaster
Final‐StatePolarization:R,N,… BSM
σ
n e–
θe
p
e
θp
e
e
EmbBB 0
WeakInteractionPhysicsa0,A0 gA
BSMPhysicsFierz Termsb,b ;D
RadiativeDecay:TripleProducts BSM
Jackson,Treiman,andWyld (1957)
PrecisionGoals
3B.Plaster
)2(9742.0V 00
ud
RC)2()16()5(9758.0VAg
nud
Marciano&Sirlin (2006)Czarnecki,Marciano,&Sirlin (2004)
*Updated0+ 0+ Vud :J.C.HardyandI.S.Towner,PRC91,025501(2015)
*
Bhattacharyaetal.(2012)
Bauman,Erler,andRamsey‐Musolf(2013)
Mendenhalletal.(2013)
0.97417(21)
PrecisionGoals
4B.Plaster
OverwhelmingMessage:Aimfor<10–3 precision
Profumo,Ramsey‐Musolf,andTulin (2007)
Bhattacharyaetal.(2012)
“A”Correlation:n pe
5B.Plaster
2A
AA0 3g1
)1|g(||g|2A
Pn
n
e
eP
Emb
A
BSM1θcos
Schematicfrom:H.Abele(2008)
“A”Correlation:n pe
6B.Plaster
Systematic Corrections < 1%
Systematic Corrections ~3 –23 %
BPetal.,PRC86,055501(2012)M.P.Mendenhalletal.,PRC87,032501(2013)
M.P.Mendenhall,Ph.D.thesis(2014)
“A”Correlation:n pe
7B.Plaster
A~0.2%
UCNALANL
A<0.6%PERC(FRM‐II,Munich)A,B,a,b,…<0.1%
ILL
B.Maerkisch,arXiv:1410.4220D.Dubbers etal.,NIMA596,238(2008)
Baessler,Bowman,Penttila,andPocanic (2014)
“a”Correlation:pe p
8B.Plaster
σ
n e–
θe
p
e
θp
Tpmax ~750eV
Kinematics:
)( ppp ep
ProtonTOF~1/pp
~Equalsensitivityas‘A’togA
aSPECT:2013:few%PERC:0.3%
Baessler,Bowman,Penttila,andPocanic (2014)G.Konradetal.(2009)
‘a’vs.‘A’recoilterms:Gardner&Zhang(2001)
“a”Correlation:pe p
9B.Plaster
aCORN atNIST:2013:~3%(stat),~2‐3%(syst)
CurrentRun:~1%
NabatSNS:Constructiona ~0.2%
Baessler,Bowman,Penttila,andPocanic (2014)F.Wietfeldt etal.(2015)
νθcos e
“B”CorrelationandFierz Termb
10B.Plaster
e
e
EmbBB 0
)()()()()(exp
ee
eee EQEQ
EQEQEB
bbEmB
e
eλ)λ(12
λ31 2
0
bb
σ
n e–
θe
p
e
θp
νp
Bhattacharyaetal.(2012)
“B”CorrelationandFierz Termb
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BP,Sjue,Wexler,andYoung(inprep)
Fierz Termb
12B.Plaster
NabatSNS:~10–3
PERC:<10–3
Baessler,Bowman,Penttila,andPocanic (2014)M.P.Mendenhall,Ph.D.thesis(2014)
K.P.Hickerson,Ph.D.thesis(2013)
GlobalFit– TheoryUncertainties
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“Rfit”Scheme:
a,A to~0.03%+ to…Tensorphysics~<limit
S.GardnerandBP(2013,2014)
Summary
14
Excitingtimeforneutrondecaymeasurementsofangularcorrelations
B.Plaster
IacknowledgesupportunderDOEAwardsDE‐FG02‐08ER41557andDE‐SC0014622
Shouldsoonrealizenewexperimentswith~10–3 precision
Extra
Second‐ClassCurrents(SCC):f3 ,g2
B.Plaster
Poorlyknownrecoil‐ordermatrixelementscanmimicorobscureScalarandTensorinteractions!
UniversalityofgV in0+ 0+
mef3/MgV = –0.0011(13)
|f3 | < (1)
MirrorTransitions
|g2 | < 0.2
Comparisonofft Values
QCDSumRuleTechniquesg2/gA = –0.0152(53)
LatticeQCD*:X0 S+nf3/gV = 0.14(9)
g2/gA = 0.68(18)
suppressedbymd/ms ~0.05
J.C.HardyandI.S.Towner,PRC79,055502(2009) D.H.Wilkinson,EPJA7,307(2000)
S.SasakiandT.Yamazaki,PRD79,074508(2009)
H.Shiomi,Nucl.Phys.A603,281(1996)
*TensionwithB.R.Holstein,PRD26,698(1982):f3/f1 = g2/g1
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1 x 108 Events
Sensitivity to b
