Baryogenesis, Leptogenesis and Lepton Flavor Violation Heinrich P - - PowerPoint PPT Presentation

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Baryogenesis, Leptogenesis and Lepton Flavor Violation Heinrich P - - PowerPoint PPT Presentation

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Baryogenesis, Leptogenesis and Lepton Flavor Violation Heinrich P as University of Hawaii Honolulu, HI, USA Super B Factory Workshop, Hawaii 2005 H. P as Baryogenesis, Leptogenesis, LFV SuperB 2005 1 Outline Status: Evidence for

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SLIDE 1

Baryogenesis, Leptogenesis and Lepton Flavor Violation

Heinrich P¨ as

University of Hawaii Honolulu, HI, USA Super B Factory Workshop, Hawaii 2005

  • H. P¨

as Baryogenesis, Leptogenesis, LFV SuperB 2005 1

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SLIDE 2

Outline

  • Status: Evidence for the baryon asymmetry
  • Requisites: Sakharov conditions for baryogenesis
  • Realization: Particle physics scenarios
  • Focus: Leptogenesis and the seesaw mechanism
  • Work out: LFV and the seesaw mechanism
  • H. P¨

as Baryogenesis, Leptogenesis, LFV SuperB 2005 2

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SLIDE 3

Evidence for the baryon asymmetry

Observation: there are more baryons than anti-baryons in the universe

  • Spectrum of anti-protons in cosmic radiation (BESS/balloon in 35 km altitude)

consistent with generation from cosmic primaries

  • no anti-nuclei found in cosmic radiation (AMS spectrometer/Discovery)
  • H. P¨

as Baryogenesis, Leptogenesis, LFV SuperB 2005 3

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Evidence for the baryon asymmetry

  • no aniihilation radiation detected in the local galaxy cluster
  • no distortion of cosmic microwave background from particle-anti-particle

annihilation in the observable universe

  • H. P¨

as Baryogenesis, Leptogenesis, LFV SuperB 2005 4

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SLIDE 5

Magnitude of baryon asymmetry

big bang nucleosynthesis: ∼ 0.1 − 180s after big bang Synthesis p, n → D,3 He,4 He,7 Li dissociated by collisions with high-energetic γ’s ⇒ sensitive to: ηB = nB−nB

nγ

Search for D,3 He,4 He,7 Li in gas clouds and stars with small metallicity ⇒ 2.6 · 10−10 < ηB < 6.2 · 10−10

  • S. Sarkar, astro-ph/0205116
  • H. P¨

as Baryogenesis, Leptogenesis, LFV SuperB 2005 5

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Magnitude of baryon asymmetry

Anisotropies in the CMB: Atomic synthesis ∼ 380000y after big bang

D.N. Spergel, Astrophys. J. Suppl. 148 (2003) 175

Acustic oscillations in the early universe Comparison 1st peak (fundamental wave: gravity ⇒ / ⇒ gas pressure) to 2nd peak (overtone: gravity ⇔ gas pressure) ⇒ Ratio baryons (gravity + gas pressure)/ cold dark matter (gravity) ⇒ Ratio ρB/ ργ ≃ 1 ⇒ ηB = 6.1+0.3

−0.2 · 10−10

  • H. P¨

as Baryogenesis, Leptogenesis, LFV SuperB 2005 6

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SLIDE 7

Baryon asymmetry as initial condition?

Possibility: ηB = 6 · 10−10 as initial condition? Inflationary epoch: ds2 = dt2 − R2(t)

  • dr2

1−kr2 + r2dθ2 + r2 sin2 θdφ2

R(t) ∝ exp(

  • Λ/3t)
  • ρΛ = Λ/8πG: Vacuum energy of inflaton field
  • ⇒ flat, homogenous und empty universe!
  • ⇒ end of inflation: decay of inflaton field into thermal plasma
  • ⇒ particles and anti-particles in equal abundances
  • ⇒ Necessity of baryogenesis after inflationary epoch
  • H. P¨

as Baryogenesis, Leptogenesis, LFV SuperB 2005 7

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Sakharov-Bedingungen for baryogenesis

  • Baryon number violation:

Interactions, which generate or annihilate B

  • Non-Equilibrium:

Γ(i( pi, si) → f( pf, sf)) = Γ(f( pf, sf) → i( pi, si)) ⇒ arrow of time

  • C violation:

Γ(i( pi, si) → f( pf, sf)) = Γ(i( pi, si) → f( pf, sf)) ⇒ different process rates for particles and anti-particles

  • CP violation:

Γ(i( pi, si) → f( pf, sf)) = Γ(i(− pi, si) → f(− pf, sf)) ⇒ different process rates for particles and anti-particles of different parities

A.D. Sakharov, 1967; V.A. Kuzmin, 1970

  • H. P¨

as Baryogenesis, Leptogenesis, LFV SuperB 2005 8

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Sakharov-Bedingungen for baryogenesis How can the Sakharov conditions be realized in a particle physics model? Baryon number violation?

  • H. P¨

as Baryogenesis, Leptogenesis, LFV SuperB 2005 9

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1st Model: GUT Baryogenesis

L

e ,

R µ , τ R R

u ,

R d , R R c , s , R t , R b R

u d

L

c s t b

L

Strong SU(2) Hypercharge

Leptons Quarks leptons <−> (scalar) sleptons bosons <−> (s=1/2) bosinos cancels divergencies benefits: dark matter candidate necessary for gravity Supersymmetry Standard Model symmetry: quarks <−> (scalar) squarks bosons <−> fermions coupling unification Grand Unified Theory quarks and leptons same multiplet in the Unification of forces Right handed neutrinos?

..."Desert"...

ν µ

L

ν τ

L L

e ν

  • H. P¨

as Baryogenesis, Leptogenesis, LFV SuperB 2005 10

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SLIDE 11

1st Model: GUT Baryogenesis

  • Baryon number violationen: GUT multiplet
  • Non-equilibrium decay of heavy X-bosons for MX > Tuniverse
  • CP-violation: Γ(X → qq) > Γ(X → qq)
  • Problem: thermal generation of X bosons with mX ∼ MGUT → high reheating

temperature after inflation Treh ∼ MGUT ≃ 1016 GeV → powerful generation of weakly interacting superpartners (gravitinos) in SUSY scenarios → decay products prevent successful BBN

Ingnatiev, Krasnikov, Kuzmin, Tavkhelidze, 1978; Yoshimura, Weinberg, 1979

  • H. P¨

as Baryogenesis, Leptogenesis, LFV SuperB 2005 11

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2nd Model: Elektroweak baryogenesis Baryon number violation already in the Standard Model?

  • H. P¨

as Baryogenesis, Leptogenesis, LFV SuperB 2005 12

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2nd Model: Elektroweak baryogenesis

Sphalerons: B violation in the Standard Model Topologically different field configurations ⇒ degenrated vacua with different baryon numbers t’Hooft 1976 T > TEW ⇒ Transitions between vacua, Baryon number violation

Kuzmin, Rubakov, Shaposhnikov, 1985

  • H. P¨

as Baryogenesis, Leptogenesis, LFV SuperB 2005 13

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2nd Model: Elektroweak baryogenesis

Electroweak phase transition ∼ 10−10 s after big bang Condensation of the Higgs field: φ = 0 → φ = v(T < Tc) ⇒ Mass generation, CP violation Non-equilibrium: analogy water-steam transition Requirement: 1st order transition ⇔ competing ground states dependent of Higgs potential ⇒ depending on Higgs self interaction λ ⇒ mH = v(T = 0) √ 2λ < 70 GeV mH > 114 GeV bei LEP too small!

  • H. P¨

as Baryogenesis, Leptogenesis, LFV SuperB 2005 14

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3rd Modell: Leptogenesis Combination of Non-equilibrium decay and baryogenesis at low energies?

  • H. P¨

as Baryogenesis, Leptogenesis, LFV SuperB 2005 15

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3rd Modell: Leptogenesis

Neutrino mass generation in the seesaw mechanism Motivation: mν ≪ mu,d,e, Standard Model: mν ≡ 0, since no right-handed neutrino

ν e

( )L

νR h

( )

+

h

Assumption: ∃ right-handed neutrino NR: “Normal” Dirac mass term mDνLNR

νR ν L

C

However: NR is a SM singlet! ⇒ Majorana mass term N RM R(NR)C, MR ≫ mD

  • E. Majorana 1937

mD+M ≡

  • νc

L

(NR) mD mD M R νL (NR)c

  • mD ≪ mR ⇒ mlight ≃ −(mD)2/M R ≪ mD

⇒ ∃ right-handed Neutrino NR with L violating mass MR ∼ 1014 GeV

  • H. P¨

as Baryogenesis, Leptogenesis, LFV SuperB 2005 16

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3rd Modell: Leptogenesis

NR decays in the early universe

  • Non-equilibrium decay of heavy neutrinos for MR > Tuniverse
  • CP violation

Γ(NR → ¯ h + ¯ νL) > Γ(NR → h + νL) ⇒ L-violation

  • B-violation: L-violation + B + L violating sphaleron processes

→ B violation ⇒ Relations to neutrino physics + lepton flavor violation!

Fukugita, Yanagida, 1986

  • H. P¨

as Baryogenesis, Leptogenesis, LFV SuperB 2005 17

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3rd Modell: Leptogenesis

∆

2

m : ∆

2

m

atm

2 ∆

2

m

sun

νL sector νR sector

θ13 θatm θsun , , 6 R−Matrix elements seesaw−Relation 18 parameters 3 mixing angles: , 1 Dirac phase 2 Majorana phases 1 absolute mass 3 Majorana masses

  • H. P¨

as Baryogenesis, Leptogenesis, LFV SuperB 2005 18

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LFV processes

Inverting the seesaw matrix: Y †

ν Yν ∝ (mD)2 ∝ MR (∼ M3)

⇒ Look for processes ∝ Y †

ν Yν

⇒ Lepton Flavor violating corrections to slepton masses!

l ~

i

l ~

j

h ~

2

νR l ~

i

l ~

j

νR ~ h 2

µe

( m )

2

δ

L

e µ χo ~ γ ~ l ~

e

l

µ

~ νµ ~

e

ν χ ~

µe

( m )

2

δ

L

e µ γ

  • H. P¨

as Baryogenesis, Leptogenesis, LFV SuperB 2005 19

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SLIDE 20

Br(µ → eγ) and Br(τ → µγ)

SUSY scenario SPS1, m1 < 0.03 eV PDG: Br(µ → eγ) < 1.2 · 10−11 (90%C.L.) ⇒ MR < 1014 − 1015 GeV Br(τ → µγ) < 10−8 (90%C.L.) : determination accuracy factor 2!

  • F. Deppisch, H. P¨

as, A. Redelbach, R. R¨ uckl, Y. Shimizu, Eur.Phys.J. C28 (2003) 365-374

  • H. P¨

as Baryogenesis, Leptogenesis, LFV SuperB 2005 20

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Gravitino bound and R-matrix elements

mSUGRA problem: overabundance of gravitinos for TR > 1010 GeV (m3/2 ≃ 1 TeV) ⇒ M1 < 10TR < 1011 GeV ⇒ x2,3 ≃ 0, π, 2π

Contours: yi = 0.1, best fit νL

  • F. Deppisch, H. P¨

as, A. Redelbach, R. R¨ uckl, in preparation

  • H. P¨

as Baryogenesis, Leptogenesis, LFV SuperB 2005 21

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SLIDE 22

Br(µ → eγ/Br(τ → µγ and x1

Strong variation of Br(µ → eγ)/Br(τ → µγ) with x1 SuperB: Br(τ → µγ) ≃ 108 ⇒ Sensitivity: Br(µ → eγ)/Br(τ → µγ) < O10−3

  • F. Deppisch, H. P¨

as, A. Redelbach, R. R¨ uckl, in preparation

  • H. P¨

as Baryogenesis, Leptogenesis, LFV SuperB 2005 22

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Conclusions

  • Cosmological evidence for baryon asymmetry
  • Inflation destroys initial asymmetry
  • Sakharov conditions: B violation, C- and CP violation, thermal

Non-equilibrium

  • GUT baryogenesis: overproduction of gravitinos
  • Elektroweak baryogenesis: Phase transition too weak
  • Leptogenesis: decays of heavy neutrino ⇒ L violation ⇒ B violation

– Seesaw mechanism: 18 parameters – ⇒ Neutrino mass constraints – ⇒ Lepton flavor violations of charged leptons: τ → µγ – ⇒ constraints on right-handed neutrino masses – Seesaw benchmark model, learn GUT scale physics! Martin Heidegger: “Das Nichts nichtet (the nothing noths)”

  • H. P¨

as Baryogenesis, Leptogenesis, LFV SuperB 2005 23

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Conclusions

CP-Verletzung und komplexe Phasen Massenbasis: (d, s, b)T Wechselwirkungsbasis: (d′, s′, b′)T Unit¨ are Transformation: (d, s, b)T = U(d′, s′, b′)T U: Mischungsmatrix Quarkstrom: Jµ = (u, c, t)OU(d, s, b)T Amplitude f¨ ur Prozess(ab → cd): M ∼ Jµ

caJ† µbd ∼ UcaU ∗ bd(ucOua)(udOub)†

Amplitude f¨ ur CP-gespiegelten Prozess: MCP ∼ CP(Jµ

ca)CP(J† µbd) ∼ UcaU ∗ bd(uaOuc)(ubOud)†

Beobachtung: MCP = M† ⇔ U reell ⇒ CP-Verletzung ⇔ komplexe Phasen in Kopplungen ⇒ CP-Verletzung erfordert nichtverschwindende Massen!

  • H. P¨

as Baryogenesis, Leptogenesis, LFV SuperB 2005 24

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SLIDE 25

Alternativen

  • Affleck-Dine Baryogenese: Skalare Superpartner von Baryonen erhalten VEVs

Supersymmetrie: flache Richtungen im Potential

  • Baryogenese an topologischen Defekten
  • Baryogenese in schwarzen L¨
  • chern

Schwarze L¨

  • cher sind vollst¨

andig durch Masse, Ladung, Drehimpuls beschrieben (“No-hair”) ⇒ Quantengravitation verletzt alle globalen Symmetrien B, L

  • Sneutrino ist das Inflaton: Nichtthermische Leptogenese im Inflatonzerfall

Neutrinophysik ⇔ Inflation

  • H. P¨

as Baryogenesis, Leptogenesis, LFV SuperB 2005 25

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SLIDE 26

Alternativen

Beziehungen zur Neutrinophysik

  • Niedrige Reheatingtemperatur ⇒ kleine MR-Masse

Davidson, Ibarra, 2002

  • CP-Verletzung in Neutrinooszillationen ⇒ Neutrino Factories und Superbeams
  • Lepton Flavor Verletzung in Prozessen mit geladenen Leptonen (seltene

Zerf¨ alle, Beschleuniger)

l ~

i

l ~

j

h ~

2

νR

µe

( m )

2

δ

L

e µ χo ~ γ ~ l ~

e

l

µ

Borzumati, Masiero, 1986; Casas, Ibarra, 2001

  • Washout f¨

ur zu große Leptonenzahlverletzung: Grenze auf die Neutrinomasse im minimalen Modell mν < ∼ 0.1 eV

Buchm¨ uller, di Bari, Pl¨ umacher, 2002

  • H. P¨

as Baryogenesis, Leptogenesis, LFV SuperB 2005 26