Transcript Single heavy MSSM Higgs production at LC

Probing Supersymmetry with Neutral
Current Scattering Experiments
Shufang Su • U. of Arizona
Sub-Z precision measurements
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neutral current scattering
heavy quark physics
CP violation, EDM
Rare K-decay, CKM unitarity
muon g-2
lepton flavor violation
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• polarized ee scattering (SLAC E158)
• polarized ep scattering (JLab Qweak)
• neutrino-nucleus scattering (NuTeV)
A. Kurylov, M. Ramsey-Musolf, SS
S. Su LOOPFESTIII
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Outline
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motivation
parity-violating electron scattering experiments
radiative corrections to weak charge QW
analysis of SUSY contributions to QW
– MSSM contributions
– RPV analysis
– distinguish various new physics / SUSY
• NuTeV experiment
– MSSM contributions
– RPV analysis
• conclusion
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Motivation
• high precision low energy experiment available
size of loop effects from new physics: (/)(M/Mnew)2
- muon g-2: M=m , new  2x10-9, exp < 10-9
– -decay, -decay: M=mW , new  10-3, exp  10-3
– parity-violating electron scattering: M=mW , new  10-3,
Qe,pW  1-4 sin2W  0.1
 1/Qe,pW 10 more sensitive to new physics
 need exp  10-2 “easier” experiment
• probe new physics off the Z-resonance
- sensitive to new physics not mix with Z
• indirect+direct: complementary information
– consistency test of theory at loop level
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Test of sin2W running
• sin2W(0) - sin2W(mZ2) = +0.007
– QCsw: agree Q2=0
– NuTeV: +3 Q2=20 (GeV)2
• parity-violating electron
scattering (PVES)
ee Moller scattering (SLAC) QeW
ep elastic scattering (J-lab) QpW

sin2
-2
2
W  0.0007 at Q =0.03 (GeV)
 clean environment: Hydrogen target
 theoretically clean: small hadronic uncertainties
 tree level  0.1  sensitive to new physics
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Goal
Develop consistency checks for theories of new physics
using the low energy precision measurements
• minimal Supersymmetric extension of SM (MSSM)
SUSY: most promising candidate for new physics
– solution to Hierarchy problem
– gauge coupling unification
– provide a natural electroweak symmetry breaking
– dark matter candidate ? (PVES)
 with R-parity : loop corrections
 without R-parity: tree-level contribution
• low-energy precision measurements
e
p
Cs
()
– PVES: weak charge Q W , Q W , ( Q W ) - NuTeV: R
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Weak charge QW
A
ALR
V
N+-NN++N-
 QfW
geA = Ie3
weak charge QfW = 2gfV = 2 If3 -4Qfs2
Qe,pW tree
Qe,pW loop
exp precision
 sin2W
SM running
ep Qweak exp QpW
ee Moller exp QeW
1-4s2
0.0721
4%
0.0007
10 
-(1-4s2)
-0.0449
8%
0.0009
8 
QCsW :  sin2W = 0.0021
S. Su LOOPFESTIII
NuTeV:  sin2W = 0.0016
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General structure of radiative corrections to QfW
Including radiative corrections:
QfW =  (2If3 - 4  Qf s2) + f
, : universal,
f: depend on fermion species
 = 1+SM+SUSY,  = 1+SM+SUSY, f= fSM+fSUSY

correction to muon life time
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Radiative contributions
QfW =  (2If3 - 4  Qf s2) + f

correction to , G and mZs2
f
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MSSM particle contents
SM particle
Spin differ by 1/2
superpartner
mass parameter
 2, m
 2, m
 2
m
qL
qR
qLR
 2, m
 2, m
 2
m
lL
lR
lLR
,
tan=vu/vd
M3
M2
M1
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One loop SUSY contributions to PVES
• gauge boson
self-energies
• external leg corrections
• vertex corrections
• box diagrams
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Numerical analysis
Model-independent analysis
• MSSM parameter range: random scan
~
~
50 GeV < mq, ml, M1,2,  < 1000 GeV
1.4 < tan < 60
 hard to impose bounds on certain MSSM parameter
 show the possible range of MSSM corrections
– impose exp search limit on SUSY particles
– impose S-T 95% CL constraints
– impose g-2 constraints (2nd slepton LR mixing)
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Correction to weak charge
QfW =  (2Tf3 - 4Qf  s2) + f
 QeW and QpW
correlated
dominant :  (<0)

negative shift in sin2W
 (QpW)SUSY / (QpW)SM < 4%,  (QeW)SUSY / (QeW)SM < 8%
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Dominant contributions
QfW =  (2Tf3 - 4Qf  s2) + f
• non-universal corrections
– vertex + wavefunction : cancel
– box diagrams numerically
suppressed
•  contribution
suppressed by (1-4 s2)
• dominant contribution
from 
 (<0)  negative shift in sin2W
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R-parity
• General MSSM, including B,L-violating operators
ijk
 L = - 1
’ijk
• dangerous  introduce proton decay
• R-parity SM particle: even superparticle: odd
– stable LSP as dark matter candidate
• RPV: only look at L-violating operator
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R-parity violating (RPV)
• RPV operators contribute to Qe,pW at tree level
Exp constraints
QpW
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 decay:RPV
|Vud| = -0.00145 MSSM
 0.0007
CLCs = -0.0040 loop
APV(Cs):95%
 QW
0.0066
Re/ :
 Re/ = -0.0042  0.0033
G :
 G = 0.00025  0.00188
No SUSY dark
matter
G
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I) Obtain 95% CL allowed region
in RPV coefficients
II) Evaluate  QWe and  QWp
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Correlation between QpW and QeW
 SUSY correction to heavy nuclei QW
•  QW (Z,N)=(2Z+N)  QuW +(2N+Z)  QdW
 QuW >0
 QdW <0

 QW(Z,N) / QW(Z,N) < 0.2 % for Cs
 Distinguish new physics
 QpW
 QeW
• MSSM:
 QCsW
small
• extra Z’:
sizable
• leptoquark:
• RPV SUSY
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Additional PV electron scattering ideas
Czarnecki, Marciano， Erler et al.
 N deep inelastic
Linear Collider e-eDIS-Parity, JLab
sin2W
DIS-Parity, SLAC
APV
SLAC E158
(ee)
S. Su LOOPFESTIII
JLab Moller
(ee)
e+e- LEP, SLD
JLab Q-Weak
(ep)
(GeV)
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NuTeV experiment
NC
R()
CC

(N  X)
(-)
(N  l-(+)X)
MSSM
R=-0.0033  0.0015

R =-0.0019  0.0026
wrong-sign contribution!
Davidson et. al., JHEP 02, 037, 2002
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R-parity violating (RPV)
• RPV operators contribute to
()
R
at tree level
either wrong sign or too small
hard to explain NuTeV deviation
NC
CC
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Conclusion
• Parity-violating ee and ep scattering
– could be used to test SM and probe new physics
– MSSM contribution to QeW and QpW is 8% and 4%  1 exp
need higher exp precision to constrain SUSY
– correlation between QeW and QpW
• distinguish various new physics
• distinguish various SUSY scenario
whether dark matter is SUSY particle ?
• SUSY contribution to NuTeV result
SUSY
is with
not R-parity:
responsible
for
the
NuTeV deviation
– MSSM
wrong
sign
/small
– negative– gluino
other contribution:
new physics ?
– size constrained by other considerations
hadronic
effects
?
– hard to –explain
NuTeV
in RPV
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