Looking for a New Angle Looking for a New Angle on CP Violationon CP Violation

Natalie RoeNatalie Roe

Lawrence Berkeley National Lawrence Berkeley National LaboratoryLaboratory

The Future of Particle PhysicsAPS/DPF Meeting, Philadelphia

April 7, 2003

The SM circa 1500The SM circa 1500 until ~1500: Earth is at the center of the fixed, perfect until ~1500: Earth is at the center of the fixed, perfect

celestial spheres (Ptolemy, 85-165 AD)celestial spheres (Ptolemy, 85-165 AD)

The First Golden AgeThe First Golden Age Astronomy:Astronomy:

Copernicus (1473-1543): Copernicus (1473-1543): Heliocentric model of the Heliocentric model of the Universe; Universe;

Physics:Physics: Galileo (1564 -1642): Law of Galileo (1564 -1642): Law of

falling bodies, concept of inertiafalling bodies, concept of inertia Precision data:Precision data:

Planetary observations by Planetary observations by Brahe, Kepler, Galileo (first Brahe, Kepler, Galileo (first telescopic observations)telescopic observations)

Synthesis:Synthesis: Newton’s Laws unifying Newton’s Laws unifying

celestial & terrestrial motioncelestial & terrestrial motion

From From Copernicus’ Copernicus’

notebooknotebook

sin2~ 0.7

Gronau-London boundon 2- 2eff

Gronau-Wiler prescription for in BDK

The Second Golden AgeThe Second Golden Age Astronomy Astronomy

1929: The galaxies are 1929: The galaxies are moving apart (Hubble)moving apart (Hubble)

PhysicsPhysics 1900 - 1920’s Quantum 1900 - 1920’s Quantum

mechanics, relativitymechanics, relativity 1928-32: Prediction of 1928-32: Prediction of

antimatter (Dirac)antimatter (Dirac) Precision dataPrecision data

accelerators , accelerators , telescopes, balloons, telescopes, balloons, satellites, underground satellites, underground detectors, etcdetectors, etc

SynthesisSynthesis

?

Standard Model

of particle physics

Standard Model of cosmology

DarkEnergy:~70% Dark

Matter:~25%

Energy budget of Universe

Antimatter: 0% ~25%

~70%

Why worry about what isn’t thereWhy worry about what isn’t there?? We know a lot about a little We know a lot about a little We have recently learned a great deal We have recently learned a great deal

more about another 1% or so more about another 1% or so We know almost nothing about almost We know almost nothing about almost

everything elseeverything else

• Standard Models of particle physics & cosmology are incomplete• New physics must involve new sources of CP violation to explain the absence of antimatter• CP violation is a clue and constraint that can distinguish among theories beyond the SMs of both particles and cosmology

Is it possible we are living in a B=0 Is it possible we are living in a B=0 Universe?Universe?

Absence of e+e- annihilation radiation => no antimatter Absence of e+e- annihilation radiation => no antimatter within our galactic cluster (20 Mpc)within our galactic cluster (20 Mpc)

Can Universe be a quilt of matter & antimatter Can Universe be a quilt of matter & antimatter domains?domains? Nuclear annihilation produces Nuclear annihilation produces from from

early universe are redshifted into early universe are redshifted into rays today rays today Gamma ray spectra empirically rule out domains Gamma ray spectra empirically rule out domains

smaller than 1000 Mpc smaller than 1000 Mpc (Cohen, deRujula, Glashow Astrophys J 495: 539-579 1998)(Cohen, deRujula, Glashow Astrophys J 495: 539-579 1998)

Sakharov’s Conditions Sakharov’s Conditions

Baryon number violationBaryon number violation

C and CP violationC and CP violation

Thermal non-equilibriumThermal non-equilibrium

1 in 101 in 1088 baryons must survive baryons must survive annihilation to generate the BAU annihilation to generate the BAU observed today:observed today:

=nB / n= (6.1± 0.30.2) x 10-10 (from WMAP)

Types of BaryogenesisTypes of Baryogenesis

Electroweak baryogenesis (SM, MSSM) Electroweak baryogenesis (SM, MSSM) GUT baryogenesisGUT baryogenesis LeptogenesisLeptogenesis Affleck-Dine mechanismAffleck-Dine mechanism Quintessential baryogenesisQuintessential baryogenesis etcetc

Baryogenesis

Occam’s RazorOccam’s Razor“Pluralitas non est ponenda“Pluralitas non est ponenda sine neccesitate” sine neccesitate”

Entities should not be multiplied unnecessarily Entities should not be multiplied unnecessarily (William of Ockham, 1280 - 1347)(William of Ockham, 1280 - 1347)

Einstein “ Everything should be made as simple Einstein “ Everything should be made as simple as possible, but not simpler.”as possible, but not simpler.”

SM model has all 3 of Sakharov’s ingredients SM model has all 3 of Sakharov’s ingredients for a matter dominated universe…for a matter dominated universe…

SM Electroweak BaryogenesisSM Electroweak Baryogenesis Baryon number violationBaryon number violation

SM anomaly ( ‘t Hooft 1976) violates B+L, conserves B-LSM anomaly ( ‘t Hooft 1976) violates B+L, conserves B-L occurs freely in early universe before EW phase transition; occurs freely in early universe before EW phase transition;

strongly suppressed today (strongly suppressed today (pp > 10 > 103333 yr) yr) EW anomaly couples to left-handed quarks & leptons; can EW anomaly couples to left-handed quarks & leptons; can

convert L convert L B B Thermal non-equilibriumThermal non-equilibrium

first order electroweak phase transition as Higgs field first order electroweak phase transition as Higgs field acquires non-zero vacuum expectation value acquires non-zero vacuum expectation value

C & CP violationC & CP violation C and P are maximally violated in weak interactionsC and P are maximally violated in weak interactions CP violation is tiny, discovered in KCP violation is tiny, discovered in K00 decays (1964) decays (1964)

Only two small problems…Only two small problems… CP violation in SM is much too small to produce CP violation in SM is much too small to produce

observed BAU…. by 10 orders of magnitude!observed BAU…. by 10 orders of magnitude! SM Higgs is heavy (LEP limit > 114 GeV), so EW SM Higgs is heavy (LEP limit > 114 GeV), so EW

phase transition is second orderphase transition is second order thus there is no departure from thermal equilibriumthus there is no departure from thermal equilibrium

1st order transition: both phases present, latent heat, change in volume

2nd order transition:

none of the above

What is Nature Telling Us?What is Nature Telling Us?

The CKM mechanism is not the sole The CKM mechanism is not the sole source for the observed CP violation?source for the observed CP violation?

CERN Courier, 1966: “We finally understand weak interactions”

CP Violation in the CKM Matrix (1973)

Complex phase

q

Vqq’ q’W

Vub*Vud

Vtb*Vtd

Vcb*Vcd

(1,0)

(,)

(0,0)

Vub*Vud

Vcb*Vcd

Vtb*Vtd

Vcb*Vcd

= sin(Cabibbo) 0.22A ~ 0.85

Wolfenstein parameterization

World average 2001

sin2= 0.48 ± 0.16

sin2 world average

New B-factory measurements are in good agreement.

World Average 2003sin2 = 0.7440.055

Regions of >95% CL

Testing the CKM Model - Testing the CKM Model - Beyond J/Beyond J/KKss

Further constraints on the U.T. from B factories:Further constraints on the U.T. from B factories: sin2sin2in additional modes in additional modes Measure Measure - is it a triangle?- is it a triangle? Improved precision on sides (VImproved precision on sides (Vub, ub, VVcb, cb, VVtdtd) - is it the ) - is it the

same triangle as determined from the angles?same triangle as determined from the angles? Rare decays & direct CP violation - signal for new Rare decays & direct CP violation - signal for new

physics?physics?

sin 2sin 2in a different modein a different mode BaBar, Belle have measured sin2BaBar, Belle have measured sin2in b in b c c s c c s

modesmodes b b s s s penguin modes also measure s s s penguin modes also measure

sin2sin2should agree within a few percent should agree within a few percent NB: New physics could enter in loops!NB: New physics could enter in loops!

Weak phase: Weak phase: 0Weak phase: 0

Suppressed by x0.04

Experimental Challenges for bExperimental Challenges for bs s

penguin modespenguin modesMode BF(Bf)

(10-6)iBFi

(10-6)

Reco. Efficiency

Purity Tagged signalevents

J/Ks 440 36.0 44% 97% 940

’Ks 29 8.7 23% ~75% 110

Ks 4 1.4 42% ~80% 34

80 fb-1 of BaBar Data

“sin 2” ” from b s penguin

’Ks

BaBar 0.02 0.34 0.03Belle 0.71 0.37 (+0.05)Ave 0.34 0.25

Ks

BaBar –0.19 (+0.52) 0.09Belle –0.73 0.64 0.22Ave –0.39 0.41

K+K-Ks non-resonantBelle 0.49 0.43 0.11 (+0.33)

’

–0.00

–0.06

–0.50

Preliminary!

sin2

Is this a hint of new physics beyond the CKM model?

Testing the CKM Model - Testing the CKM Model - Beyond J/Beyond J/KKss

Further constraints on the U.T. from B factories:Further constraints on the U.T. from B factories: sin2sin2in additional modes for consistency checkin additional modes for consistency check Measure Measure - is it a triangle?- is it a triangle? Improved precision on sides (VImproved precision on sides (Vub, ub, VVcb, cb, VVtdtd) - is it the same triangle ) - is it the same triangle

as determined from the angles?as determined from the angles? Rare decays & direct CP violation - signal for new physics?Rare decays & direct CP violation - signal for new physics?

Measurements in BMeasurements in Bss decays decays Tev RunIITev RunII: B: Bss mixing, CP violation mixing, CP violation BTeV, LHCbBTeV, LHCb - next generation of precision CP measurements - next generation of precision CP measurements

Measure Measure in K in K decaysdecays CKM, KOPIOCKM, KOPIO for charged & neutral modes for charged & neutral modes

What is Nature Telling Us?

The CKM mechanism is not the sole source for the observed CP violation?

EW baryogenesis involves new particles with additional CPV phases and dynamics?

Electroweak Baryogenesis in the Electroweak Baryogenesis in the Minimal Supersymmetric SMMinimal Supersymmetric SM

v≠0

v=0

v≠0v≠0

tR~ t

Chiral chargino current => asymmetry in left and right-handed top quarks

EW anomaly partially converts tL asymmetry into L asymmetry but tR is unaffected => net B asymmetry

tL+ tR > tL+ tR

tL< tL tR> tR

Can we test MSSM EWB?Can we test MSSM EWB? MSSM EWB requires light right-handed scalar top (< mMSSM EWB requires light right-handed scalar top (< mtt) and light ) and light

chargino chargino (Carena et al, Nuc Phys B599, 158 (2001))(Carena et al, Nuc Phys B599, 158 (2001))

opportunity for TeV RunII and for LHCopportunity for TeV RunII and for LHC No new CP violation in B’s, but mixing may be enhanced No new CP violation in B’s, but mixing may be enhanced

lattice calculations needed to reduce theoretical uncertaintylattice calculations needed to reduce theoretical uncertainty Bs mixing would also show an effectBs mixing would also show an effect

SUSY also may affect b SUSY also may affect b s s

EW baryogenesis in MSSM is testable - the lamp post under which we EW baryogenesis in MSSM is testable - the lamp post under which we can look.can look.

d

d

b

b

tR

tR

~

~

d d

b s

Murayama & Pierce, hep-ph 0201261

Status of b Status of b ss

What is Nature Telling Us?

The CKM mechanism is not the sole source for the observed CP violation?

EW baryogenesis involves new particles with additional CPV phases and dynamics?

EW baryogenesis is not the source of the BAU; try something else?

“Surface of last scattering” - CMB T=3000 K (~1 eV)

EW Phase transitionEM & weak forces decouple; T ~ 300 GeV

Inflation, GUT era

T= 1015 GeV

Today T=2.73 K

Today: 14 billion years

10-35 s

10-11 s

1 s

0.4 Myr

GUT BaryogenesisGUT BaryogenesisThermal non-equilibrium

heavy particles (1010 - 1015 GeV) produced in thermal equilibrium in hot dense early universe decay more slowly than Universe expands, resulting in out-of-equilibrium abundance at later times

Baryon number violationoccurs naturally in models which seek to unify quarks, leptons; heavy GUT particles violate B in their decays

C and CP violationfrom interference between tree and one-loop diagrams for B violating decays of heavy particles

Elegant, economical and completely untestable…

LeptogenesisLeptogenesisThermal non-equilibrium

heavy particles (N) produced in thermal equilibrium at early times are right-handed Majorana ’s see-saw mechanism explains light mass: m1/mN

Baryon number violationN violates L in its decay; excess L is converted to excess B via SM EW anomaly (violates B+L but conserves B-L)

C and CP violationfrom interference between tree and one-loop diagrams for decay of N

N

H

N

H

H

N+

N

N

Can Leptogenesis be Tested?Can Leptogenesis be Tested? Violation of lepton flavor => established in Violation of lepton flavor => established in oscillations!oscillations!

Light but non-zero Light but non-zero masses are consistent with masses are consistent with see-saw mechanism and heavy Nsee-saw mechanism and heavy N

CP violation in light CP violation in light sector? Different phase from sector? Different phase from that in N decay => circumstantial evidencethat in N decay => circumstantial evidence

Confirmed detection of 0Confirmed detection of 0decay, establishing decay, establishing the Majorana nature of the Majorana nature of ’s ’s would provide even would provide even more compelling circumstantial evidence…more compelling circumstantial evidence…

Sum of all light Sum of all light masses in range 0.001 - 0.1 eV is masses in range 0.001 - 0.1 eV is required to obtain correct required to obtain correct (Buchmuller et al hep-ph 0302092 )(Buchmuller et al hep-ph 0302092 )

CERN Courier, 1966: “We finally understand weak interactions”

2003: “We finally understand CP Violation”

ConclusionConclusion

CP violation is a necessary ingredient in a baryon-CP violation is a necessary ingredient in a baryon-dominated Universe and required in new physics dominated Universe and required in new physics

Precision data in the quark and neutrino sector are Precision data in the quark and neutrino sector are sensitive probes of new physics, and may ultimately sensitive probes of new physics, and may ultimately shed light on the mystery of baryogenesis shed light on the mystery of baryogenesis

The particle physics discoveries of the next decade The particle physics discoveries of the next decade will have profound impact on our understanding of the will have profound impact on our understanding of the Universe as we go beyond the SM - both of them!Universe as we go beyond the SM - both of them!