Some Comments on CP-Violation and Leptogenesis

Introduction

SOMECOMMENTSON CP-VIOLATIONANDLEPTOGENESIS

Marco Drewes TU München

23. 8. 2016, NuFact, Quy Nhon, Vietnam

SOMECOMMENTSON CP-VIOLATIONANDLEPTOGENESIS 1 / 7 Introduction The Standard Model and General Relativity together explain almost all phenomena observed in nature, but...

gravity is not quantised

a handful of observations remain unexplained neutrino oscillations - the only signal found in the lab! baryon asymmetry of the universe - leptogenesis? dark matter - sterile neutrinos? accelerated cosmic expansion (Dark Energy, inﬂation)

planck.cf.ac.uk SOMECOMMENTSON CP-VIOLATIONANDLEPTOGENESIS 2 / 7 Introduction

125 GeV

ﬁgure by M. Shaposhnikov

SOMECOMMENTSON CP-VIOLATIONANDLEPTOGENESIS 3 / 7 Introduction

MaD/Garbrecht 1502.00477

SOMECOMMENTSON CP-VIOLATIONANDLEPTOGENESIS 4 / 7 Introduction High scale leptogenesis Lepton asymmetries are characterised by CP violating parameter 3 M = 1 ( ) α † 2 Im Fα1 mν αβFβ1 16π (F F)11v

Φ Φ Φ lβ Φ NI NI NI NJ

lβ lα Φ lα lα q 1 diag Yukawa matrix F = v Uν mν √MM ,Casas/Ibarra complex rotation matrix R R Vanilla leptogenesis P Asymmetry only depends on = α α Dependency on Uν drops out baryon asymmetry only depends on complex "Euler angles" in ⇒ R Flavoured leptogenesis No sum over α baryon asymmetry depends on both, complex ⇒ angles in and the phases in Uν R SOMECOMMENTSON CP-VIOLATIONANDLEPTOGENESIS 5 / 7 Introduction Low scale leptogenesis I is experimentally accessible

plot from MaD/Garbrecht/Gueter/Klaric 1606.06690 see also Canetti/MaD/Frossard/Shaposhnikov 1208.4607

Hernandez/Kekic/Lopez-Pavon/Salvado 1606.06719 Abada/Arcadi/Domcke/Lucente 1507.06215

can explain baryon asymmetry with PMNS phases alone

106

104

100 10 MeV D

eV 100 MeV @ 1 M D 1 GeV 0.01

10-4 10 GeV

10-6 0.01 0.1 1 10 100 1000 eIm HΩL Canetti/MaD/Frossard/Shaposhnikov 1208.4607

SOMECOMMENTSON CP-VIOLATIONANDLEPTOGENESIS 6 / 7 Introduction Low scale leptogenesis II

δ affects active-sterile ﬂavour mixing pattern

0.5

0.4

2 2 0.3 sin θ23 = 0.576 / U

2 2 μ sin 23 = 0.45

U θ

0.2 δ= 256°

0.1

0.0 0.0 0.2 0.4 0.6 0.8

2 2 Ue /U CP-violation in sterile sector may be measued at SHiP (?)

Cvetic/Zamora-Saa

SOMECOMMENTSON CP-VIOLATIONANDLEPTOGENESIS 7 / 7 Introduction

some slides that may be useful for the discussion

SOMECOMMENTSON CP-VIOLATIONANDLEPTOGENESIS 8 / 7 We need New Physics! Could the same New Physics solve these puzzles? Can we probe it in the lab?

Introduction

Neutrinos have masses.

There is (almost) no antimatter in the observable universe.

There are 1010 times more photons in the observable ∼ universe than nuclei.

SOMECOMMENTSON CP-VIOLATIONANDLEPTOGENESIS 9 / 7 Introduction

Neutrinos have masses.

There is (almost) no antimatter in the observable universe.

There are 1010 times more photons in the observable ∼ universe than nuclei.

We need New Physics! Could the same New Physics solve these puzzles? Can we probe it in the lab?

SOMECOMMENTSON CP-VIOLATIONANDLEPTOGENESIS 9 / 7 Introduction

125 GeV

ﬁgure by M. Shaposhnikov

SOMECOMMENTSON CP-VIOLATIONANDLEPTOGENESIS 10 / 7 c three light neutrinos ν Uν (νL + θν ) ' R mostly "active" SU(2) doublet T 2 −1 T light masses mν ' θMM θ = v FMM F T c three heavy neutrinos N νR + θ ν ' L mostly "sterile" singlets heavy masses MN ' MM

Majorana masses MM introduce new mass scale(s) MI 2 2 new heavy states only interact via small mixing U = θaI 1 aI | |

Introduction Neutrino masses: Seesaw mechanism

SOMECOMMENTSON CP-VIOLATIONANDLEPTOGENESIS 11 / 7 Introduction Neutrino masses: Seesaw mechanism

¯ ˜ † ˜ † 1 ¯c † c = + iν¯R∂ν/ R LLFνRH ν¯RF LH (ν RMM νR +ν ¯RM ν ) L LSM − − − 2 M R Minkowski 1979, Gell-Mann/Ramond/Slansky 1979, Mohapatra/Senjanovic 1979, Yanagida 1980, Schechter/Valle 1980 c 1 c 0 mD νL (νL νR) T ⇒ 2 mD MM νR −1 −1 two sets of Majorana mass states with mixing θ = mDMM = vFMM c three light neutrinos ν Uν (νL + θν ) ' R mostly "active" SU(2) doublet T 2 −1 T light masses mν ' θMM θ = v FMM F T c three heavy neutrinos N νR + θ ν ' L mostly "sterile" singlets heavy masses MN ' MM

Majorana masses MM introduce new mass scale(s) MI 2 2 new heavy states only interact via small mixing UaI = θaI 1 SOMECOMMENTSON CP-VIOLATIONANDLEPTOGENESIS| | 11 / 7 Introduction

MaD/Garbrecht 1502.00477

SOMECOMMENTSON CP-VIOLATIONANDLEPTOGENESIS 12 / 7 SM: sphalerons violate B, but conserve B − L at T > 140 GeV Yukawa couplings F violate individual lepton ﬂavour numbers in addition MM violates total lepton number

SM: weak interaction violates P and CP, but CP-violation insufﬁcient additional complex phases in F violate CP

SM: Hubble expansion unsufﬁcient, no EW phase transition Y NI production ("freeze in leptogenesis")

Akhmedov/Rubakov/Smirnov Yeq

NI freezeout and decay ("freeze out leptogenesis")

Fukugita/Yanagida M/T

Introduction Leptogenesis: Sakharov conditions

baryon number violation

C and CP violation

nonequilibrium

SOMECOMMENTSON CP-VIOLATIONANDLEPTOGENESIS 13 / 7

baryon asymmetry is generated during NI production at T > 140 GeV

NI freezeout and decay at T M 140 GeV produce large late time lepton asymmetry ∼ Yukawa couplings F violate individual lepton ﬂavour numbers in addition MM violates total lepton number

additional complex phases in F violate CP

Y NI production ("freeze in leptogenesis")

Akhmedov/Rubakov/Smirnov Yeq

NI freezeout and decay ("freeze out leptogenesis")

Fukugita/Yanagida M/T

Introduction Leptogenesis: Sakharov conditions

baryon number violation SM: sphalerons violate B, but conserve B − L at T > 140 GeV

C and CP violation SM: weak interaction violates P and CP, but CP-violation insufﬁcient

nonequilibrium SM: Hubble expansion unsufﬁcient, no EW phase transition

SOMECOMMENTSON CP-VIOLATIONANDLEPTOGENESIS 13 / 7

baryon asymmetry is generated during NI production at T > 140 GeV

NI freezeout and decay at T M 140 GeV produce large late time lepton asymmetry ∼ additional complex phases in F violate CP

Y NI production ("freeze in leptogenesis")

Akhmedov/Rubakov/Smirnov Yeq

NI freezeout and decay ("freeze out leptogenesis")

Fukugita/Yanagida M/T

Introduction Leptogenesis: Sakharov conditions

nonequilibrium SM: Hubble expansion unsufﬁcient, no EW phase transition

SOMECOMMENTSON CP-VIOLATIONANDLEPTOGENESIS 13 / 7

baryon asymmetry is generated during NI production at T > 140 GeV

NI freezeout and decay at T M 140 GeV produce large late time lepton asymmetry ∼ Y NI production ("freeze in leptogenesis")

Akhmedov/Rubakov/Smirnov Yeq

NI freezeout and decay ("freeze out leptogenesis")

Fukugita/Yanagida M/T

Introduction Leptogenesis: Sakharov conditions

baryon number violation SM: sphalerons violate B, but conserve B − L at T > 140 GeV Yukawa couplings F violate individual lepton flavour numbers in addition MM violates total lepton number C and CP violation SM: weak interaction violates P and CP, but CP-violation insufficient additional complex phases in F violate CP nonequilibrium SM: Hubble expansion unsufficient, no EW phase transition

SOMECOMMENTSON CP-VIOLATIONANDLEPTOGENESIS 13 / 7

baryon asymmetry is generated during NI production at T > 140 GeV

NI freezeout and decay at T M 140 GeV produce large late time lepton asymmetry ∼ Introduction Leptogenesis: Sakharov conditions

Akhmedov/Rubakov/Smirnov Yeq

NI freezeout and decay ("freeze out leptogenesis")

Fukugita/Yanagida M/T SOMECOMMENTSON CP-VIOLATIONANDLEPTOGENESIS 13 / 7

baryon asymmetry is generated during NI production at T > 140 GeV

NI freezeout and decay at T M 140 GeV produce large late time lepton asymmetry ∼ Introduction

Vanilla Leptogenesis (freeze out)Fukugita/Yanagida

NI are produced thermally very early at T > M freeze out and decay at T . M CP-violating decay produces L = 0 6 Φ Φ Φ lβ Φ NI NI NI NJ

lβ lα Φ lα lα L = 0 is partly transferred into B = 0 by sphalerons 6 6 Boltzmann equations (x = M/T ) see e.g. Buchmüller/Plümacher

dY xH N = Γ (Y Y eq) dx − N N − N dYB−L eq xH = Γ (Y Y ) c Γ Y − dx N N − N − W N B L SOMECOMMENTSON CP-VIOLATIONANDLEPTOGENESIS 14 / 7 Introduction

ﬁrst principles derivation of kinetic equations Anisimov/Buchmuller/MaD/Mendizabal, Beneke/Garbrecht/Herranen/Schwaller, Garny/Hohenegger/Kartavtsev, Dev/Millington/Pilaftsis/Teresi

quasiparticle dispersion relations Giudice/Notari/Raidal/Riotto 04, Plumacher/Kiessig 12

momentum dependency Hahn-Woernle/Plumacher/Wong 09, Asaks/Eijima/Ishida 12, Bodeker/Wormann 14

production rate ΓN Salvio/Lodone/Strumia 11, Laine 12, Besak/Bodeker 12, Biondini/Brambilla/Escobedo/Vairo 13, Garbrecht/Glowna/Herranen 13, Garbrecht/Glowna/Schwaller 13, Ghisoiu/Laine 14, Ghiglieri/Laine 15, Ghiglieri/Laine 16

washout rates cW ΓN Bodeker/Laine 14, Ghisoiu/Laine 14, Ghiglieri/Laine 16

CP violating parameter Biondini/Brambilla/Escobedo/Vairo 15

behaviour near resonance Garny/Hohenegger/Kartavtsev 11, Garbrecht/Herranen 11, Dev/Millington/Pilaftsis/Teresi 11

ﬂavour effects Abada/Davidson/Ibarra/Josse-Michaux/Losada/Riotto 06, Nardi/Nir/Roulet/Racker 06, Jose-Michaux/Abada 07, Aristazabal Sierra/Munoz/Nardi 09, Racker/Pena/Rius 12, Beneke/Fidler/Garbrecht/Herranen/Schwaller 11, ...

low scale leptogenesis parameter space this talk

SOMECOMMENTSON CP-VIOLATIONANDLEPTOGENESIS 15 / 7 Introduction Low scale leptogenesis

Yeq

M/T

SOMECOMMENTSON CP-VIOLATIONANDLEPTOGENESIS 16 / 7 Overdamped regime

Introduction

Leptogenesis from N-oscillations (freeze-in) Oscillating regime

SOMECOMMENTSON CP-VIOLATIONANDLEPTOGENESIS 17 / 7 Introduction

Leptogenesis from N-oscillations (freeze-in) Oscillating regime Overdamped regime

SOMECOMMENTSON CP-VIOLATIONANDLEPTOGENESIS 17 / 7 Introduction Leptogenesis with two heavy neutrinos

plot from MaD/Garbrecht/Gueter/Klaric 1606.06690

see also Canetti/MaD/Frossard/Shaposhnikov 1208.4607, Hernandez/Kekic/Lopez-Pavon/Salvado 1606.06719 and

Abada/Arcadi/Domcke/Lucente 1507.06215 Requires mass degeneracy and small mixing...... but CP-violation may also be measurable Cvetic/Kim/Zamora-Saa 1403.2555 SOMECOMMENTSON CP-VIOLATIONANDLEPTOGENESIS 18 / 7 Introduction Flavour mixing predictions 0.5

U2 0.4

2.25×10 -6

2.00×10 -6 0.3 1.75×10 -6

2 1.50×10 -6 / U 2 μ

U 1.25×10 -6

0.2 1.00×10 -6

7.50×10 -7

5.00×10 -7

0.1 2.50×10 -7

0.0 0.0 0.2 0.4 0.6 0.8 1.0

2 2 Ue /U

2 2 2 allowed relative mixings Ua /U for given U and M = 1 GeV and IH measuring Dirac phase δ would considerably reduce allowed regions

SOMECOMMENTSON CP-VIOLATIONANDLEPTOGENESIS 19 / 7 neutrino oscillation data LFV in rare lepton decays violation of lepton universality, (apparent) violation of CKM unitarity neutrinoless double β-decay EW precision data

LNV and LFV in gauge boson or meson decays

meson or D,B N lepton antilepton −

l l displaced vertices, SHiP peak searches, missing 4-momentum

Introduction

How to ﬁnd the NI? see e.g. MaD arXiv:1303.6912 [hep-ph]

Indirect searches see e.g. MaD/Garbrecht 1502.00477

Direct searches see e.g. Antusch/Fischer 1502.05915, Deppisch/Dev 1502.06541

Cosmology: BBN and Neff see e.g. Hernandez/Kekic/Lopez-Pavon 1406.2961

Astrophysics: X-ray, SN, pulsars, structure formation review 1602.04816 SOMECOMMENTSON CP-VIOLATIONANDLEPTOGENESIS 20 / 7 LNV and LFV in gauge boson or meson decays

meson or D,B N lepton antilepton −

l l displaced vertices, SHiP peak searches, missing 4-momentum

Introduction

How to ﬁnd the NI? see e.g. MaD arXiv:1303.6912 [hep-ph]

Indirect searches see e.g. MaD/Garbrecht 1502.00477 neutrino oscillation data LFV in rare lepton decays violation of lepton universality, (apparent) violation of CKM unitarity neutrinoless double β-decay EW precision data

Direct searches see e.g. Antusch/Fischer 1502.05915, Deppisch/Dev 1502.06541

Cosmology: BBN and Neff see e.g. Hernandez/Kekic/Lopez-Pavon 1406.2961

Astrophysics: X-ray, SN, pulsars, structure formation review 1602.04816 SOMECOMMENTSON CP-VIOLATIONANDLEPTOGENESIS 20 / 7 Introduction

How to ﬁnd the NI? see e.g. MaD arXiv:1303.6912 [hep-ph]

Direct searches see e.g. Antusch/Fischer 1502.05915, Deppisch/Dev 1502.06541 LNV and LFV in gauge boson or meson decays

meson or D,B N lepton antilepton −

l l displaced vertices, SHiP peak searches, missing 4-momentum

Cosmology: BBN and Neff see e.g. Hernandez/Kekic/Lopez-Pavon 1406.2961

Astrophysics: X-ray, SN, pulsars, structure formation review 1602.04816 SOMECOMMENTSON CP-VIOLATIONANDLEPTOGENESIS 20 / 7 Introduction Direct searches

plot by Bhupal Dev see talks by Bhupal Dev, Un-ki Yang, Eric van Herwijnen

SOMECOMMENTSON CP-VIOLATIONANDLEPTOGENESIS 21 / 7 Introduction Indirect searches Example: leptogenesis and neutrinoless double β-decay

10-9

range of KamLAND-Zen upper limit 10-10

-11 [ GeV ] 10 ββ m

10-12

10-13 0 1 2 3 4 5

M [GeV]

plot from MaD/Eijima 1606.06221

see also Hernandez/Kekic/Lopez-Pavon/Racker/Salvado 1606.06719, Asaka/Eijima/Hiroyuki 1606.06686

SOMECOMMENTSON CP-VIOLATIONANDLEPTOGENESIS 22 / 7 Introduction Summary

Heavy right handed neutrinos can be the common origin of neutrino masses and baryons in the universe.

Much progress has been made in the quantitative understanding of leptogenesis

If the heavy neutrino masses are below the TeV scale, they can be found in experiments.

The requirement to explain the neutrino masses and the baryon asymmetry impose strong constraints on the properties of the heavy neutrinos. If any heavy neutral leptons are found in experiments in the future, these can be used to asses whether the new particles are indeed the common origin of neutrino masses and matter in the universe.

SOMECOMMENTSON CP-VIOLATIONANDLEPTOGENESIS 23 / 7