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Introduction Neutrino oscillations Leptogenesis Experimental searches
LAB-TO-GENESIS
HOW TO FIND THE ORIGIN OF MATTER IN EXISTING EXPERIMENTS
Marco DrewesTU München
based onarXiv:1404.7114 [hep-ph],
Phys.Rev.Lett. 110 (2013) 6, 061801 ,JHEP 1303 (2013) 096 ,
Phys.Rev. D87 (2013) 093006and work in progress
2013 review: arXiv:1303.6912 [hep-ph] Int.J.Mod.Phys. E22 (2013) 1330019
Kosmologietag 2014, Bielefeld
1 / 17LAB-TO-GENESIS, HOW TO FIND THE ORIGIN OF MATTER IN EXISTING EXPERIMENTS
Introduction Neutrino oscillations Leptogenesis Experimental searches
The Standard Model and General Relativity together explainalmost all phenomena in nature, but. . .
gravity is not quantized
a handful of observations remain unexplained
neutrino oscillations
baryon asymmetry of the universe
dark matter
geometry of the universe
2 / 17LAB-TO-GENESIS, HOW TO FIND THE ORIGIN OF MATTER IN EXISTING EXPERIMENTS
Introduction Neutrino oscillations Leptogenesis Experimental searches
Can we probe the New Physics empirically?
3 / 17LAB-TO-GENESIS, HOW TO FIND THE ORIGIN OF MATTER IN EXISTING EXPERIMENTS
Introduction Neutrino oscillations Leptogenesis Experimental searches
4 / 17LAB-TO-GENESIS, HOW TO FIND THE ORIGIN OF MATTER IN EXISTING EXPERIMENTS
Introduction Neutrino oscillations Leptogenesis Experimental searches
5 / 17LAB-TO-GENESIS, HOW TO FIND THE ORIGIN OF MATTER IN EXISTING EXPERIMENTS
Introduction Neutrino oscillations Leptogenesis Experimental searches
Neutrino masses: Seesaw mechanism
L = LSM + i ν̄R /∂νR − L̄LFνRΦ̃ − ν̄RF †LΦ̃† −1
2(ν̄c
RMMνR + ν̄RM†Mνc
R)
Majorana masses MM introduce new mass scale(s)
six (Majorana) mass eigenstates
two sets of mass states with small mixing θ � 1here θ = mDM−1
M = vFM−1M
6 / 17LAB-TO-GENESIS, HOW TO FIND THE ORIGIN OF MATTER IN EXISTING EXPERIMENTS
Introduction Neutrino oscillations Leptogenesis Experimental searches
Neutrino masses: Seesaw mechanism
L = LSM + i ν̄R /∂νR − L̄LFνRΦ̃ − ν̄RF †LΦ̃† −1
2(ν̄c
RMMνR + ν̄RM†Mνc
R)
Majorana masses MM introduce new mass scale(s)
six (Majorana) mass eigenstates
two sets of mass states with small mixing θ � 1here θ = mDM−1
M = vFM−1M
three light neutrinos νi ' Uν(νL + θνcR)i
mostly "active" SU(2) doubletmasses ∼ mν = θMMθT
three heavy neutrinos NI ' νR + θT νcL
mostly "sterile" singletsheavy masses MI ∼ MM
6 / 17LAB-TO-GENESIS, HOW TO FIND THE ORIGIN OF MATTER IN EXISTING EXPERIMENTS
Introduction Neutrino oscillations Leptogenesis Experimental searches
Can we probe this New Physics empirically?
7 / 17LAB-TO-GENESIS, HOW TO FIND THE ORIGIN OF MATTER IN EXISTING EXPERIMENTS
Introduction Neutrino oscillations Leptogenesis Experimental searches
plot from 1204.5379
8 / 17LAB-TO-GENESIS, HOW TO FIND THE ORIGIN OF MATTER IN EXISTING EXPERIMENTS
Introduction Neutrino oscillations Leptogenesis Experimental searches
Leptogenesis
fermion number violationsphalerons violate B, but conserve B − L at T > 140 GeVYukawa couplings F violate individual lepton flavour numbersin addition MM violates total lepton number
9 / 17LAB-TO-GENESIS, HOW TO FIND THE ORIGIN OF MATTER IN EXISTING EXPERIMENTS
Introduction Neutrino oscillations Leptogenesis Experimental searches
Leptogenesis
fermion number violationsphalerons violate B, but conserve B − L at T > 140 GeVYukawa couplings F violate individual lepton flavour numbersin addition MM violates total lepton number
C and CP violationweak interaction violates Padditional complex phases in F violate CP
9 / 17LAB-TO-GENESIS, HOW TO FIND THE ORIGIN OF MATTER IN EXISTING EXPERIMENTS
Introduction Neutrino oscillations Leptogenesis Experimental searches
Leptogenesis
fermion number violationsphalerons violate B, but conserve B − L at T > 140 GeVYukawa couplings F violate individual lepton flavour numbersin addition MM violates total lepton number
C and CP violationweak interaction violates Padditional complex phases in F violate CP
nonequilibrium
NI production
NI freezeout
NI decay
Y
Yeq
M/T
baryon asymmetry is generated during NI production at T > 140 9 / 17LAB-TO-GENESIS, HOW TO FIND THE ORIGIN OF MATTER IN EXISTING EXPERIMENTS
Introduction Neutrino oscillations Leptogenesis Experimental searches
Leptogenesis during NI-freezeout/decay
Majorana fermions NI can decay into leptons or antileptons
The probabilities for both decays are different due to theCP-violation in F
decay violates total lepton number L
sphalerons convert part of L into B
Φ
lα
NI NJNINI
Φ
lαlαΦ
Φlβ
Φ
lβ
NJ
Fukugita/Yanagida 1986
10 / 17LAB-TO-GENESIS, HOW TO FIND THE ORIGIN OF MATTER IN EXISTING EXPERIMENTS
Introduction Neutrino oscillations Leptogenesis Experimental searches
Leptogenesis during NI production
CP-violating oscillations amongst NI generate L 6= 0 during theirthermal production
sphalerons convert part of L into B
Akhmedov/Rubakov/Smirnov 1998, Asaka/Shaposhnikov 2006
With two RH neutrinos this requires a mass degeneracy ∼ 10−3
Canetti/MaD/Frossard/Shaposhnikov 1208.4607
With three RH neutrinos no such degeneracy is needed!
MaD/Garbrecht 1206.5537
11 / 17LAB-TO-GENESIS, HOW TO FIND THE ORIGIN OF MATTER IN EXISTING EXPERIMENTS
Introduction Neutrino oscillations Leptogenesis Experimental searches
Why is 2 RH neutrinos different from 3 RH neutrinos?
asymmetry is larger if generated at earlier times⇒ grows with |FαI | as ΓI = (F †F )IIγav T
but washout rates Γα = (FF †)ααγav T also grow with |FαI |
12 / 17LAB-TO-GENESIS, HOW TO FIND THE ORIGIN OF MATTER IN EXISTING EXPERIMENTS
Introduction Neutrino oscillations Leptogenesis Experimental searches
Why is 2 RH neutrinos different from 3 RH neutrinos?
asymmetry is larger if generated at earlier times⇒ grows with |FαI | as ΓI = (F †F )IIγav T
but washout rates Γα = (FF †)ααγav T also grow with |FαI |
two RH neutrinos:NI-coupling to all flavours governed by only one parameter
NI coupling to different flavours "tied together"large ΓI necessarily imply large washout for all flavoursBAU can only be explained if |FαI | are very smallCP-violation must be enhanced by mass degeneracy ∼ 10−3
three RH neutrinos:individual |FαI | can be very different in size
flavour asymmetric washoutasymmetry in individual flavour(s) can survive in spite of observablylarge NI -mixing
12 / 17LAB-TO-GENESIS, HOW TO FIND THE ORIGIN OF MATTER IN EXISTING EXPERIMENTS
Introduction Neutrino oscillations Leptogenesis Experimental searches
Experimental signatures
W
N0
i
W
q1
q2
q3
q4
lα
lβ
13 / 17LAB-TO-GENESIS, HOW TO FIND THE ORIGIN OF MATTER IN EXISTING EXPERIMENTS
Introduction Neutrino oscillations Leptogenesis Experimental searches
Experimental signatures
for 5 GeV < MI < mZ
NI produced in Z -decays (e.g. at LEP)same sign dilepton signal
14 / 17LAB-TO-GENESIS, HOW TO FIND THE ORIGIN OF MATTER IN EXISTING EXPERIMENTS
Introduction Neutrino oscillations Leptogenesis Experimental searches
Experimental signatures
for 5 GeV < MI < mZ
NI produced in Z -decays (e.g. at LEP)same sign dilepton signal
for 2GeV < MI < 5 GeV (LHCb, BELLE, SHIP)
NI produced in B-meson decaysB− → NIµ
− → π+µ−µ− etc give same sign dilepton signalsensitivity ∼
√Lint
BELLE can also do "peak searches" for missing 4-momentumsensitivity ∼ Lint
14 / 17LAB-TO-GENESIS, HOW TO FIND THE ORIGIN OF MATTER IN EXISTING EXPERIMENTS
Introduction Neutrino oscillations Leptogenesis Experimental searches
Experimental signatures
for 5 GeV < MI < mZ
NI produced in Z -decays (e.g. at LEP)same sign dilepton signal
for 2GeV < MI < 5 GeV (LHCb, BELLE, SHIP)
NI produced in B-meson decaysB− → NIµ
− → π+µ−µ− etc give same sign dilepton signalsensitivity ∼
√Lint
BELLE can also do "peak searches" for missing 4-momentumsensitivity ∼ Lint
for MI < 2 GeV (SHIP)
NI produced in D-meson decaysexisting bounds very strong⇒ can only be improved by dedicated fixed target experiments
14 / 17LAB-TO-GENESIS, HOW TO FIND THE ORIGIN OF MATTER IN EXISTING EXPERIMENTS
Introduction Neutrino oscillations Leptogenesis Experimental searches
Leptogenesis with two RH neutrinos
0.2 0.5 1.0 2.0 5.0 10.010-12
10-10
10-8
10-6
M @GeVD
U2
BAU
BAU
Seesaw
BBN
PS191
NuTeV
CHARM
U2 ≡ trθ†θ
Canetti/MaD/Frossard/Shaposhnikov 1208.4607
15 / 17LAB-TO-GENESIS, HOW TO FIND THE ORIGIN OF MATTER IN EXISTING EXPERIMENTS
Introduction Neutrino oscillations Leptogenesis Experimental searches
Leptogenesis with three RH Neutrinos
1 2 3 4 510−9
10−7
10−5
0.001
past experiments
BELLE
LHCb
baryogenesis
M2 [GeV]
U2 µ
Canetti/MaD/Garbrecht 1404.7114
16 / 17LAB-TO-GENESIS, HOW TO FIND THE ORIGIN OF MATTER IN EXISTING EXPERIMENTS
Introduction Neutrino oscillations Leptogenesis Experimental searches
Probing the origin of matter in the laboratory
W
N0
i
W
q1
q2
q3
q4
lα
lβ
two RH neutrinos three RH neutrinos
baryogenesis requires mass degeneracy works without degeneracy
lab searches SHIP 1310.1762 LHCb, BELLE, SHIP,. . .
Smirnov/Kersten, Atre/Han/Pascoli/Zhang, Canetti/MaD/Shaposhnikov, . . .
17 / 17LAB-TO-GENESIS, HOW TO FIND THE ORIGIN OF MATTER IN EXISTING EXPERIMENTS