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The Standard ModelThe Standard ModelA A beautifulbeautiful theory that explains almost all of particle physics with theory that explains almost all of particle physics with only about 20 parameters.only about 20 parameters.
+
y py p
BUT…BUT…
1.1. Why 20 parameters?Why 20 parameters?
Dark Dark
2.2. Doesn’t explain Doesn’t explain observed cosmologyobserved cosmology
Dark Dark energyenergy
mattermatterMatterMatter
3. Hierarchy problem: why M3. Hierarchy problem: why MEWEW << << MMPlanckPlanck ??
Physical Higgs Physical Higgs y ggy ggboson mass:boson mass:
TreeTree--level level parameterparameter OneOne--looploop
Supersymmetry is super!Supersymmetry is super!The minimal The minimal supersymmetricsupersymmetric standard model (MSSM):standard model (MSSM):
+ +
Coupling unificationCoupling unificationHierarchy problemHierarchy problem
Dark Dark and visible matterand visible matter Stringy motivationStringy motivation
Outline:Outline:
1 Beta‐decay correlation coefficients1. Beta decay correlation coefficients
OneOne--loop SUSY contributions lead to fourloop SUSY contributions lead to four--ff l h (l h ( ) () ( ))fermionfermion couplings that are not (Vcouplings that are not (V--A)x(VA)x(V--A).A).
How do SUSYHow do SUSY--induced contributions manifest in induced contributions manifest in the betathe beta decay spectrum?decay spectrum?the betathe beta--decay spectrum?decay spectrum?
How large can they be?How large can they be?
Outline:Outline:
2 Baryogenesis and Electric Dipole Moments2. Baryogenesis and Electric Dipole Moments
b d db d dBaryon asymmetry can be produced in MSSM via Baryon asymmetry can be produced in MSSM via Electroweak Electroweak BaryogenesisBaryogenesis..
Same MSSM CPSame MSSM CP--violating violating phases give rise to both phases give rise to both baryogenesisbaryogenesis and EDMsand EDMsbaryogenesisbaryogenesis and EDMsand EDMs
How do EDMs constrain How do EDMs constrain b ib i ??
PospelovPospelov & Ritz, 2005& Ritz, 2005baryogenesisbaryogenesis??
Beta‐decayBeta decay
• Correlation coefficients:Correlation coefficients:
Jackson, Jackson, TreimanTreiman, , WyldWyld (1957)(1957),, ,, yy ( )( )
Coefficients Coefficients parametrizeparametrize beta spectrum, can be computed e.g. beta spectrum, can be computed e.g.
In SMIn SM
Also studied by Gardner and Zhang (2000)Also studied by Gardner and Zhang (2000)
Beta‐decayBeta decay
• Beyond the SMBeyond the SMMost general fourMost general four--fermionfermion interaction, with arbitrary coefficientsinteraction, with arbitrary coefficients
Other combinations Other combinations of Dirac matricesof Dirac matrices
SScalarcalar VVectorector TTensorensor
In the SM:In the SM: , and all other parameters vanish., and all other parameters vanish.
In the MSSM:In the MSSM:Goes into Goes into VVudud
KurylovKurylov et al (2002)et al (2002)
Beta‐decayBeta decayCan relate beta decay parameters to nonCan relate beta decay parameters to non--(V(V--A)A)--coefficientscoefficients
SUSY contributionsSUSY contributions
Example of SUSY box graph that Example of SUSY box graph that contributes to betacontributes to beta--decaydecay
LLRR
xx
Consider e.g.Consider e.g.
LL
xx
LLRRRequires LR Requires LR squarksquark and and sleptonslepton mixingmixing
ProfumoProfumo, Ramsey, Ramsey--MusolfMusolf, S.T. (2006), S.T. (2006)
Usually people assumeUsually people assume
And thenAnd then
SUSY contributionsSUSY contributionsFierzFierz interference for interference for supersuper--allowed decaysallowed decayssupersuper--allowed decaysallowed decays
FierzFierz interference for interference for neutron decayneutron decay
(Assuming: real coefficients, (Assuming: real coefficients, VudVud = 1, form factors = 1, form factors gAgA = = gTgT = 1)= 1)
Neutron decay Neutron decay corelationcorelation between n spin and neutrino momentum between n spin and neutrino momentum
Also in MSSM only: we haveAlso in MSSM only: we have
SUSY contributionsSUSY contributionsConsidered large LR mixingConsidered large LR mixing
No reason to prefer large LR mixing, but it is a valid (and often ignored) No reason to prefer large LR mixing, but it is a valid (and often ignored) region of MSSM parameter spaceregion of MSSM parameter space
ProfumoProfumo, Ramsey, Ramsey--MusolfMusolf, S.T. (2006), S.T. (2006)
Experimental boundsExperimental boundsCurrent:Current:
Hardy & Towner (2004)Hardy & Towner (2004)
Agrees with SM. See e.g. Marciano & Agrees with SM. See e.g. Marciano & SirlinSirlin (1993), (1993), CiriglianoCirigliano & & RosellRosell (2007(2007))
Prospective:Prospective:Prospective:Prospective:
See Kevin See Kevin Hickerson’sHickerson’s talktalk
MSSM lives in blue boxMSSM lives in blue box
Fantasy boundsFantasy bounds
Decreasing all Decreasing all Decreasing all Decreasing all experimental experimental limits by order limits by order of magnitudeof magnitude
Implications of large LR‐mixingImplications of large LR mixing
Is there a constraint on LR‐mixing?
Absence of spontaneous Absence of spontaneous breaking of color/EM (along Dbreaking of color/EM (along D--breaking of color/EM (along Dbreaking of color/EM (along Dflat directions) requiresflat directions) requires
f = u, d, ef = u, d, ex3x3
Requires heavy Higgs sectorRequires heavy Higgs sector
Higgs sector reviewHiggs sector review SM: 1 Higgs MSSM: 5 HiggsSM: 1 Higgs MSSM: 5 Higgs
Requires heavy Higgs sectorRequires heavy Higgs sector
ConclusionsConclusions
1. 10‐3 SUSY contributions to beta‐decay correlation1. 10 SUSY contributions to beta decay correlation coefficients possible‐ Requires heavy Higgs sector (still have one light SM‐
like Higgs)
‐ Why? Why not?
2. If O(10‐3) deviations found, interesting implications for MSSMfor MSSM
Baryogenesis at Electroweak ScaleBaryogenesis at Electroweak Scale
We want to explainPDG
kl lp
Dunkley et al [WMAP5]
95% C.L.
based on dynamics during the electroweak phase transition.
Timeline of universeTimeline of universe
NucleosynthesisNucleosynthesis
1 min1 minElectroweak scaleElectroweak scale
NowNow
13.7 13.7 GyrGyrRecombinationRecombination
380,000 yr380,000 yr1 min1 min
1010--1010 ss
Era of electroweak symmetry breaking:Era of electroweak symmetry breaking:
Higgs field acquires a vacuum expectation value (Higgs field acquires a vacuum expectation value (vevvev))
Fermions and W,Z bosons get massiveFermions and W,Z bosons get massive
Electroweak Phase TransitionElectroweak Phase Transition
First order electroweak phase transition during the early universe
Higgs potentialHiggs potentialV( )
T > Tc T = Tc
T =0
High T: EW symmetry restored from thermal corrections to Higgs potential
Low T: EW symmetry broken
At critical temp T degenerate minima Just below T quantum At critical temp Tc, degenerate minima. Just below Tc, quantum tunneling from to bubble nucleation!
Electroweak Baryogenesis PictureElectroweak Baryogenesis Picture
Three Steps:Three Steps:
Cohen, Kaplan, Nelson, 1992-1994; Huet, Nelson, 1996
pp
1. Nucleation and expansion of 1. Nucleation and expansion of bubbles of broken EW symmetrybubbles of broken EW symmetry
2 CP2 CP violating interactions at violating interactions at moving bubble 2. CP2. CP--violating interactions at violating interactions at
bubble wall induces charge bubble wall induces charge density, diffusing outside bubbledensity, diffusing outside bubble
3 Sphalerons convert LH 3 Sphalerons convert LH
bubble wall
electroweak
3. Sphalerons convert LH 3. Sphalerons convert LH asymmetry into B asymmetryasymmetry into B asymmetry
diffusionCPCP
y electroweak sphaleron
um
ber
den
sity
Quar
k nu
Electroweak Baryogenesis Picture
Three Steps:Three Steps:
Cohen, Kaplan, Nelson, 1992-1994; Huet, Nelson, 1996
Electroweak Baryogenesis Picture
pp
1. Nucleation and expansion of 1. Nucleation and expansion of bubbles of broken EW symmetrybubbles of broken EW symmetry
2 CP2 CP violating interactions at violating interactions at moving bubble 2. CP2. CP--violating interactions at violating interactions at
bubble wall induces charge bubble wall induces charge density, diffusing outside bubbledensity, diffusing outside bubble
3 Sphalerons convert LH 3 Sphalerons convert LH
bubble wall
4. Baryon asymmetry 4. Baryon asymmetry d b d b bbld b d b bbl
electroweak
3. Sphalerons convert LH 3. Sphalerons convert LH asymmetry into B asymmetryasymmetry into B asymmetry
diffusionCPCP
y
captured by expanding bubblecaptured by expanding bubble
electroweak sphaleron
um
ber
den
sity
Quar
k nu
Electroweak baryogenesis in the d d d lStandard Model
M i f M i f S kh S kh di idi iMust satisfy Must satisfy Sakharov Sakharov conditionsconditions::
1.1. Baryon number Baryon number violation:violation:
P id d b SM P id d b SM l t k l t k h lh lProvided by SM Provided by SM electroweak electroweak sphaleronssphalerons::
-- active in early universe for T > 100 active in early universe for T > 100 GeVGeV
2.2. CC-- and and CPCP--violation: violation:
CKM phase insufficient for CKM phase insufficient for baryogenesisbaryogenesisCKM phase insufficient for CKM phase insufficient for baryogenesisbaryogenesis
3. Departure from thermal equilibrium:3. Departure from thermal equilibrium:
mmhh > 114 > 114 GeVGeV means no firstmeans no first--order phase transitionorder phase transitionhh pp
Electroweak baryogenesis in the Standard Model
M i f M i f S kh S kh di idi iMust satisfy Must satisfy Sakharov Sakharov conditionsconditions::
1.1. Baryon number Baryon number violation:violation:
P id d b SM P id d b SM l t k l t k h lh lProvided by SM Provided by SM electroweak electroweak sphaleronssphalerons::
-- active in early universe for T > 100 active in early universe for T > 100 GeVGeV
2.2. CC-- and and CPCP--violation: violation:
CKM phase insufficient for CKM phase insufficient for baryogenesisbaryogenesis
New CPNew CP--violating violating phases in MSSM!phases in MSSM!
CKM phase insufficient for CKM phase insufficient for baryogenesisbaryogenesis
3. Departure from thermal equilibrium:3. Departure from thermal equilibrium:
mmhh > 114 > 114 GeVGeV means no firstmeans no first--order phase transitionorder phase transitionhh ppFirstFirst--order phase transition in MSSM! (as long as order phase transition in MSSM! (as long as rightright--handed top handed top squarksquark is lighter than 125 is lighter than 125 GeVGeV))
Carena et al (2008)
Electric Dipole MomentsElectric Dipole MomentsSame CPSame CP--violating phases that produce baryon asymmetry also violating phases that produce baryon asymmetry also give rise to EDMsgive rise to EDMsgive rise to EDMsgive rise to EDMs
If EDM measured, then If EDM measured, then can “predict” baryon can “predict” baryon asymmetryasymmetry
If limit set on EDM, then If limit set on EDM, then limit on MSSM parameter limit on MSSM parameter spacespaceasymmetryasymmetry spacespace
Computing the Baryon AsymmetryComputing the Baryon AsymmetryComputing the Baryon AsymmetryComputing the Baryon AsymmetrySolve Boltzmann equations for Solve Boltzmann equations for particle particle species in the species in the plasma, with plasma, with
background of expanding bubble of broken background of expanding bubble of broken EW symmetryEW symmetry
diffusiondiffusion collisionscollisions CPCP--violating violating sourcesource
nnii = number density for = number density for particles particles —— antiparticlesantiparticles
1. Want to solve for charge densities n1. Want to solve for charge densities nii
(particle number density) (particle number density) (anti(anti particle number density)particle number density)(particle number density) (particle number density) –– (anti(anti--particle number density)particle number density)
2. LH 2. LH fermionfermion charge density generates baryon numbercharge density generates baryon number
Computing the Baryon AsymmetryComputing the Baryon AsymmetryComputing the Baryon AsymmetryComputing the Baryon AsymmetrySolve Boltzmann equations for Solve Boltzmann equations for particle particle species in the species in the plasma, with plasma, with
background of expanding bubble of broken background of expanding bubble of broken EW symmetryEW symmetry
diffusiondiffusion collisionscollisions CPCP--violating violating sourcesource
nnii = number density for = number density for particles particles —— antiparticlesantiparticles
1. CPV source induces 1. CPV source induces HiggsinoHiggsinodensity inside bubble walldensity inside bubble wall
Distance from bubble wallDistance from bubble wall
Cirigliano, Lee, Ramsey-Musolf, S.T. (2006)
Computing the Baryon AsymmetryComputing the Baryon AsymmetryComputing the Baryon AsymmetryComputing the Baryon AsymmetrySolve Boltzmann equations for Solve Boltzmann equations for particle particle species in the species in the plasma, with plasma, with
background of expanding bubble of broken background of expanding bubble of broken EW symmetryEW symmetry
diffusiondiffusion collisionscollisions CPCP--violating violating sourcesource
nnii = number density for = number density for particles particles —— antiparticlesantiparticles
1. CPV source induces 1. CPV source induces HiggsinoHiggsinodensity inside bubble walldensity inside bubble wall
2. 2. HiggsinoHiggsino density diffusesdensity diffuses
Distance from bubble wallDistance from bubble wall
Cirigliano, Lee, Ramsey-Musolf, S.T. (2006)
Computing the Baryon AsymmetryComputing the Baryon AsymmetryComputing the Baryon AsymmetryComputing the Baryon AsymmetrySolve Boltzmann equations for Solve Boltzmann equations for particle particle species in the species in the plasma, with plasma, with
background of expanding bubble of broken background of expanding bubble of broken EW symmetryEW symmetry
diffusiondiffusion collisionscollisions CPCP--violating violating sourcesource
nnii = number density for = number density for particles particles —— antiparticlesantiparticles
1. CPV source induces 1. CPV source induces HiggsinoHiggsinodensity inside bubble walldensity inside bubble wall
2. 2. HiggsinoHiggsino density diffusesdensity diffuses
3. Inelastic scattering produces 3. Inelastic scattering produces leftleft--handed fermionshanded fermions
Distance from bubble wallDistance from bubble wallttLLttLL
Cirigliano, Lee, Ramsey-Musolf, S.T. (2006)ttRR ttRR~~
Comparison of different groupsComparison of different groupsComparison of different groupsComparison of different groupsVarious results:Various results:
CarenaCarena, , QuirosQuiros, , SecoSeco, Wagner (2000), Wagner (2000)Following Following RiottoRiotto (1997); Lee(1997); Lee, , CiriglianoCirigliano, Ramsey, Ramsey--MusolfMusolf (2004)(2004)
plotted vs. plotted vs. ,,for Mfor M = 200 GeV= 200 GeV CiriglianoCirigliano, Ramsey, Ramsey MusolfMusolf (2004)(2004)for Mfor M22 = 200 GeV= 200 GeV
andand
Factor of 10 Factor of 10 discrepencydiscrepency
BalazsBalazs, , CarenaCarena, , MenonMenon, Morrissey, , Morrissey, Wagner (2004)Wagner (2004)
KonstandinKonstandin, , ProkopecProkopec, Schmidt, , Schmidt, SecoSeco(2005)(2005)
discrepencydiscrepency
EDMs from MSSM phasesEDMs from MSSM phases
TeVTeV--scalescale
New CPNew CP--violating phases in SUSY violating phases in SUSY sector contribute to onesector contribute to one--loop graphsloop graphssector contribute to onesector contribute to one--loop graphsloop graphs
Below the Below the TeVTeV--scalescale
Integrating out SUSY particles Integrating out SUSY particles leaves higher dim EDM operators for leaves higher dim EDM operators for leaves higher dim EDM operators for leaves higher dim EDM operators for SM particlesSM particles
EDMEDM ChromoChromo--EDMEDM
EDMs from MSSM phasesEDMs from MSSM phases
PospelovPospelov & Ritz (2005)& Ritz (2005)
Complicated problem to relate observable EDMs to Complicated problem to relate observable EDMs to the underlying CPthe underlying CP--violating phasesviolating phases
Electric Dipole MomentsElectric Dipole Moments
Three most restrictive EDMs:
R t l (2002)R t l (2002)
Baker et al. (2006)Baker et al. (2006)
Regan et al. (2002)Regan et al. (2002)
RomalisRomalis et al. (2001)et al. (2001)
PospelovPospelov & Ritz (2005), Falk et al (1999)& Ritz (2005), Falk et al (1999)
EDMs in the MSSMEDMs in the MSSM
One‐loop EDMs in MSSM are generally big!“SUSY CP Problem”
MMSUSYSUSY = 500 = 500 GeVGeV
ee
Taking common Taking common susysusy mass, mass, O(1) h l ibl f O(1) h l ibl f ep
ton
epto
nphas
ephas
e
O(1) phases only possible for O(1) phases only possible for MMSUSYSUSY > > TeVTeV
Squar
kSquar
k//sl
esl
e
GauginoGaugino//HiggsinoHiggsino phasephaseLoophole: Assume 1st/2nd generation Loophole: Assume 1st/2nd generation sleptonssleptons//squarkssquarks are heavy are heavy
“Irreducible” two‐loop EDMsIrreducible two loop EDMs
Even if one‐loop EDMs suppressed, have two‐loop contributionsp pp , p
FirstFirst--order order phase transition phase transition phase transition phase transition + LEP bound on + LEP bound on Higgs massHiggs mass
Gives EDM sensitive to Gives EDM sensitive to squarksquark//sleptonslepton phasephase
Gives EDM sensitive to Gives EDM sensitive to gauginogaugino//HiggsinoHiggsino phasephase
Li, Profumo, Ramsey-Musolf (2008) Pilaftsis (1999); Chang, Chang, Keung (1999)f = u, d, ef = u, d, e
squarksquark//sleptonslepton phasephasegauginogaugino//HiggsinoHiggsino phasephase
Suppressed in MSSM Suppressed in MSSM baryogenesisbaryogenesis
MSSM BaryogenesisMSSM Baryogenesisee oo
//Hig
gsi
no
Hig
gsi
no
ddTlTl ddnn ddHgHg
esis
esis
epto
nep
ton
phas
ephas
e
Gau
gin
Gau
gin
phas
ephas
e
l l bar
yogen
ebar
yogen
e
Squar
kSquar
k//sl
esl
e
Succ
essf
uSucc
essf
u
GauginoGaugino (Wino) mass(Wino) mass
GauginoGaugino//HiggsinoHiggsino phasephase
GauginoGaugino (Wino) mass(Wino) mass
Li, Profumo, Ramsey-Musolf (2008)
Baryogenesis in f hExtensions of the MSSM
Several possibilities:Several possibilities:Several possibilities:Several possibilities:
1. Add new degrees of freedom: Singlet extension of MSSM 1. Add new degrees of freedom: Singlet extension of MSSM e.g. NMSSM, e.g. NMSSM, nMSSMnMSSM, U(1)’MSSM , U(1)’MSSM
Kang, Langacker, Li, Liu (2004)
Balasz, Carena, Menon, Morrissey, Wagner (2004)
Huber and Schmidt (2000)
2. Add new higher2. Add new higher--dimensional operatorsdimensional operators
“Beyond“Beyond--thethe--MSSM” modelMSSM” model Dine, Seiberg, Thomas (2007)
Add dimAdd dim--5 operators to MSSM5 operators to MSSM
For For baryogenesisbaryogenesis: can have light stops/: can have light stops/sbottomssbottoms and still obey and still obey Higgs mass LEP boundHiggs mass LEP bound Blum Nir (2008) Higgs mass LEP boundHiggs mass LEP bound Blum, Nir (2008)
“Irreducible” two‐loop EDMsIrreducible two loop EDMs
In extensions of the MSSM, both diagrams can be relevant.
“Beyond‐the‐MSSM” scenario: include dim‐5 operators in MSSM
Li, Profumo, Ramsey-Musolf (2008) Pilaftsis (1999); Chang, Chang, Keung (1999)f = u, d, ef = u, d, e
Gives EDM sensitive to Gives EDM sensitive to squarksquark//sleptonslepton phasephase
Gives EDM sensitive to Gives EDM sensitive to gauginogaugino//HiggsinoHiggsino phasephase
Baryogenesis Beyond‐the‐MSSMa yoge es s eyo d t e SS
dd dd dd
has
ehas
e
ddTlTl ddnn ddHgHg
ase
ase
//sle
pto
nsl
epto
nph
ph
slep
ton
slep
ton
pha
pha
Squar
kSquar
k//
Squar
kSquar
k//
GauginoGaugino//HiggsinoHiggsino phasephase GauginoGaugino//HiggsinoHiggsino phasephase
Blum, Delaunay, Losada, Nir, S.T. (in prep)Preliminary results (may change)Preliminary results (may change)
ConclusionsConclusions
• EDMs provide powerful probes of electroweakEDMs provide powerful probes of electroweak baryogenesis in the MSSM
• Future directions:• Future directions:– Experiments will improve sensitivities by orders of magnitudemagnitude
– Theorists will try to find new ways for electroweak baryogenesis to be viablebaryogenesis to be viable
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