Electroweak Physics at an Electron-Ion Collider M.J. Ramsey- Musolf Wisconsin-Madison QuickTime™ TIFF (Uncompres are needed to QuickTime™ and a decompressor are needed to see this picture. http://www.physics.wisc.edu/groups/ particle-theory/ NPAC Theoretical Nuclear, Particle, Astrophysics & Cosmology ECT* Trento, July 2008
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Electroweak Physics at an Electron-Ion ColliderM.J. Ramsey-MusolfWisconsin-MadisonQuickTime™ and aTIFF (Uncompressed) decompressorare needed to see this picture.
Rules out the SM! Rules out SUSY!Favors Technicolor!
Rules out Technicolor!Favors SUSY!
(also APV in Cs) (also Moller @ E158)
W. MarcianoThe Average: sin2θw = 0.23122(17)
3σ apart
•Precision sin2W measurements at colliders very challenging•Neutrino scattering cannot compete statistically•No resolution of this issue in next decade
d(x)/u(x): large x Electroweak test: e-q couplings & sin2W
Higher Twist: qq and qqg correlations
Charge sym in pdfs
€
up (x) = dn (x)?
d p (x) = un (x)?
PVDIS & QCD
Low energy effective PV eq interaction
PV DIS eD asymmetry: leading twist
Higher Twist (J Lab)
CSV (J Lab, EIC)
d/u (J Lab, EIC) +
PVDIS & CSV
€
up (x) = dn (x)?
d p (x) = un (x)?
•Direct observation of parton-level CSV would be very exciting!•Important implications for high energy collider pdfs•Could explain significant portion of the NuTeV anomaly
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u(x) = up (x) − dn (x)
δd(x) = d p (x) − un (x)
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RCSV =δAPV (x)
APV (x)= 0.28
δu(x) −δd(x)
u(x) + d(x)
Londergan & Murdock
Few percent A/A
Adapted from K. Kumar
PVDIS & d(x)/u(x): xK1
Adapted from K. Kumar
SU(6): d/u~1/2Valence Quark: d/u~0
Perturbative QCD: d/u~1/5
PV-DIS off the proton(hydrogen target)
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APV =GFQ2
2παa(x) + f (y)b(x)[ ]
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a(x) =u(x) + 0.91d(x)
u(x) + 0.25d(x)
Very sensitive to d(x)/u(x)
A/A ~ 0.01
PVES at an EIC
Scale-dependence of Weak Mixing
JLab Future
SLAC Moller
Parity-violating electron scattering
EIC PVDIS ?
Z0 pole tension
EIC Moller ?
Charged Current Processes
• The NuTeV Puzzle
• HERA Studies
• W Production at an EIC ? CC/NC ratios ?
Weak Mixing in the Standard Model
Scale-dependence of Weak Mixing
JLab Future
SLAC Moller
νnucleus deep inelasticscattering
Z0 pole tension
The NuTeV Puzzle
Rν =σνNNC σνN
CC =gL2 +rgR
2
Rν =σν NNC σ ν N
CC =gL2 +r−1gR
2
gL,R2 =
ρνNNC
ρνNCC
⎛
⎝ ⎜ ⎞
⎠ ⎟
2
(εL ,Rq
q∑ )2
r =σνNCC σν N
CC
Rνexp−Rν
SM =−0.0033±0.0007
Rν exp−Rν
SM =−0.0019±0.0016
R− =
Rν −rRν
1−r=(1−2sin2θW) /2+L
Paschos-Wolfenstein
SUSY Loops
RPV SUSY
Wrong sign
Other New CC Physics?
Low-Energy Probes
Nuclear & neutron decay
Pion leptonic decay
Polarized -decay
O / OSM ~ 10-3
O / OSM ~ 10-4
O / OSM ~ 10-2
HERA W production
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O / OSM ~ 10-1
A. Schoning (H1, Zeus)
Lepton Number & Flavor Violation
• LNV & Neutrino Mass
• ν Mechanism Problem
• LFV as a Probe
• K e Conversion at EIC ?
ν-Decay: LNV? Mass Term?
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e−
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e−
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νM
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W −
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W −
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A Z,N( )
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A Z − 2,N + 2( )0.1
1
10
100
1000
Effective
( )Mass meV
12 3 4 5 6 7
12 3 4 5 6 7
12 3 4 5 6 7
1 ( )Minimum Neutrino Mass meV
U1e = .866 m2
sol = 7 meV
2
U2e = .5 m2
atm = 2 meV
2
U 3e =
Inverted
Normal
Degenerate
Dirac Majorana
-decayLong baseline
?
?
Theory Challenge: matrix elements+ mechanism
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mν
EFF= Uek
2mk e2iδ
k
∑
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e−
€
e−
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χ 0
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˜ e −
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u
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u
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d
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d
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˜ e −€
e−
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e−
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νM
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W −
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W −
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u
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u
€
d
€
d
mνEFF & neutrino spectrum
Normal Inverted
ν-Decay: LNV? Mass Term?
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e−
€
e−
€
νM
€
W −
€
W −
€
A Z,N( )
€
A Z − 2,N + 2( )0.1
1
10
100
1000
Effective
( )Mass meV
12 3 4 5 6 7
12 3 4 5 6 7
12 3 4 5 6 7
1 ( )Minimum Neutrino Mass meV
U1e = .866 m2
sol = 7 meV
2
U2e = .5 m2
atm = 2 meV
2
U 3e =
Inverted
Normal
Degenerate
Dirac Majorana
-decayLong baseline
?
?
Theory Challenge: matrix elements+ mechanism
€
mν
EFF= Uek
2mk e2iδ
k
∑
€
e−
€
e−
€
χ 0
€
˜ e −
€
u
€
u
€
d
€
d
€
˜ e −€
e−
€
e−
€
νM
€
W −
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W −
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u
€
u
€
d
€
d
mνEFF & neutrino spectrum
Normal Inverted
See-saw mechanism
Leptogenesis
νL νLνR
H H
Lepton Asym ! Baryon Asym
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QuickTime™ and aTIFF (Uncompressed) decompressor
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GERDA CUORE
EXO Majorana
ν-Decay: Mechanism
Dirac Majorana
Theory Challenge: matrix elements+ mechanism
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mν
EFF= Uek
2mk e2iδ
k
∑
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e−
€
e−
€
χ 0
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˜ e −
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u
€
u
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d
€
d
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˜ e −€
e−
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e−
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νM
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W −
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W −
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u
€
u
€
d
€
d
Mechanism: does light νM exchange dominate ?
How to calc effects reliably ? How to disentangle H & L ?
O(1) for ~ TeV Does operator power counting suffice?
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n
€
n
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p
€
p
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ˆ O 0νββL
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u
€
d€
u
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d
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e−
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e−
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N
€
N€
€
€
e−
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e−
Prezeau, R-M, Vogel: EFT
ν-Decay: Interpretation
0.1
1
10
100
1000
Effective
( )Mass meV
12 3 4 5 6 7
12 3 4 5 6 7
12 3 4 5 6 7
1 ( )Minimum Neutrino Mass meV
U1e = .866 m2
sol = 7 meV
2
U2e = .5 m2
atm = 2 meV
2
U 3e =
Inverted
Normal
Degenerateν signal equivalent to degenerate hierarchy
Loop contribution to mν of inverted hierarchy scale