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Lecture VIII: Cosmic Frontier Connections

ACFI NLDBD School 10/31-11/3 2017!

M.J. Ramsey-Musolf U Mass Amherst

http://www.physics.umass.edu/acfi/

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Lecture VIII Goals

•  Provide some background on leptogenesis in the broader context of baryogenesis

•  Discuss some implications of 0νββ-decay searches for leptogenesis

•  Provide some background on cosmological probes of neutrino mass**

•  Invite questions !

** Disclaimer: not my primary area of expertise

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Lecture VIII Outline

I.  Origin of Matter: Leptogenesis

II.  Neutrino Mass from Cosmology

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I. Origin of Matter: Leptogenesis

Symmetries & Cosmic History

Standard Model Universe

EW Symmetry Breaking: Higgs

QCD: n+p! nuclei

QCD: q+g! n,p…

Astro: stars, galaxies,..

10-35 s

10-11 s 10-5 s

~ 1 m

380k yr

Symmetries & Cosmic History

Standard Model Universe

EW Symmetry Breaking: Higgs

BSM Physics?

QCD: n+p! nuclei

QCD: q+g! n,p…

Astro: stars, galaxies,..

10-35 s

10-11 s 10-5 s

~ 1 m

380k yr

The Origin of Matter

Explaining the origin, identity, and relative fractions of the cosmic energy budget is one of the most compelling motivations for physics beyond the Standard Model

Cosmic Energy Budget

Dark Matter

Dark Energy

68 %

27 %

5 %

Baryons Baryons

The Origin of Matter

Explaining the origin, identity, and relative fractions of the cosmic energy budget is one of the most compelling motivations for physics beyond the Standard Model

Cosmic Energy Budget

Dark Matter

Dark Energy

68 %

27 %

5 %

Baryons Baryons

Cosmic Baryon Asymmetry

Big Bang Nucleosynthesis:

Light element abundances depend on YB

Cosmic Microwave Bcknd:

Shape of anisotropies depends on YB

uILi = (Su)ij umass

Lj (49)

uIRi = (Tu)ij umass

Rj (50)

dILi = (Sd)ij dmass

Lj (51)

dIRi = (Td)ij dmass

Rj (52)

VCKM

= S†uSd (53)

V LCKM

= S†uSd (54)

(55)

V RCKM

= T †uTd (56)

V RCKM

= T †uTd (57)

H1�body

=GFp

2

⌘

2mN

~� · ~r ⇢(~r) (58)

⌘ / GF sin � sin ✓1

sin ✓2

sin ✓3

(59)

dA(199Hg) = S S

(60)

= 2.8⇥ 10�4 fm�2

(61)

S = �1.4⇥ 10�8 e� fm3

YB =nB

s= (8.59 ± 0.11)⇥ 10�11

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Symmetries & Cosmic History

Standard Model Universe

EW Symmetry Breaking: Higgs

QCD: n+p! nuclei

QCD: q+g! n,p…

Astro: stars, galaxies,..

10-35 s

10-11 s 10-5 s

~ 1 m

380k yr

How did we go from nothing to something ?

BSM Physics?

Ingredients for Baryogenesis

•  B violation (sphalerons)

•  C & CP violation

•  Out-of-equilibrium or CPT violation

Ingredients for Baryogenesis

•  B violation (sphalerons)

•  C & CP violation

•  Out-of-equilibrium or CPT violation

Standard Model BSM

✔

✖

✖

✔

✔

✔

Ingredients for Baryogenesis

•  B violation (sphalerons)

•  C & CP violation

•  Out-of-equilibrium or CPT violation

Standard Model BSM

✔

✖

✖

✔

✔

✔

Scenarios: leptogenesis, EW baryogenesis, Afflek-Dine, asymmetric DM, cold baryogenesis, post-sphaleron baryogenesis…

Symmetries & Cosmic History

Standard Model Universe

EW Symmetry Breaking: Higgs

QCD: n+p! nuclei

QCD: q+g! n,p…

Astro: stars, galaxies,..

?

Baryogenesis: When? CPV? SUSY? Neutrinos?

10-35 s

10-11 s 10-5 s

~ 1 m

380k yr

Symmetries & Cosmic History

Standard Model Universe

EW Symmetry Breaking: Higgs

QCD: n+p! nuclei

QCD: q+g! n,p…

Astro: stars, galaxies,..

?

Baryogenesis: When? CPV? SUSY? Neutrinos?

EW Baryogenesis: testable w/ EDMs + colliders

10-35 s

10-11 s 10-5 s

~ 1 m

380k yr

Leptogenesis: look for ingred’s w/ νs: DBD, ν osc

Baryogenesis Scenarios E

nerg

y S

cale

(GeV

)

1012

Affleck Dine 109

10 2 10-1

Standard thermal lepto

Electroweak, resonant lepto, WIMPY baryo, ARS lepto…

Post-sphaleron, cold…

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What Questions Does It Address ?

•  Is the neutrino its own antiparticle ?

•  Why is there more matter than antimatter ?

•  Why are neutrino masses so small?

New heavy neutrino-like particle = its own anti-particle

“See saw mechanism” “Leptogenesis”

Heavy neutrino decays in early universe generate baryon asym

ν = ν

Neutrinos and the Origin of Matter

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m2 ⇡MN (37)

�(N ! `H) 6= �(N ! ¯`H⇤) (38)

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•  Heavy neutrinos decay out of equilibrium in early universe

•  Majorana neutrinos can decay to particles and antiparticles

•  Rates can be slightly different (CP violation)

•  Resulting excess of leptons over anti-leptons partially converted into excess of quarks over anti-quarks by Standard Model sphalerons

Neutrinos and the Origin of Matter

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m2 ⇡MN (37)

�(N ! `H) 6= �(N ! ¯`H⇤) (38)

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•  Heavy neutrinos decay out of equilibrium in early universe

•  Majorana neutrinos can decay to particles and antiparticles

•  Rates can be slightly different (CP violation)

•  Resulting excess of leptons over anti-leptons partially converted into excess of quarks over anti-quarks by Standard Model sphalerons

Neutrinos and the Origin of Matter

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•  Heavy neutrinos decay out of equilibrium in early universe

✓MX

�M

◆>> 1 (79)

gX << 1 (80)

U↵N ⇠ mD

MN

(81)

U↵N ⇠r

vL

vR

� m⌫

MN

(82)

+⇣NR, NR

⌘(83)

�L =

✓�+

p2 �+

�0 ��+

p2

◆(84)

mL ⇠ ghL h�0

Li (85)

mN ⇠ ghR h�0

Ri (86)

�N ⌘ �(NR ! `H) + �(NR ! ¯H⇤) =|h|28⇡

MN (87)

�N(z) =K

1

(z)

K2

(z)�N (88)

H(T ) ⇠ 1.66 g⇤T 2

MP

(89)

�(`H ! NR)

MN

(90)

H(T )

MN

(91)

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NR

H

l h

Hubble rate

✓MX

�M

◆>> 1 (79)

gX << 1 (80)

U↵N ⇠ mD

MN

(81)

U↵N ⇠r

vL

vR

� m⌫

MN

(82)

+⇣NR, NR

⌘(83)

�L =

✓�+

p2 �+

�0 ��+

p2

◆(84)

mL ⇠ ghL h�0

Li (85)

mN ⇠ ghR h�0

Ri (86)

�N ⌘ �(NR ! `H) + �(NR ! ¯H⇤) =|h|28⇡

MN (87)

�N(z) =K

1

(z)

K2

(z)�N (88)

H(T ) ⇠ 1.66 g⇤T 2

MP

(89)

�(`H ! NR)

MN

(90)

H(T )

MN

(91)

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+ NR

H*

l h

_

Neutrinos and the Origin of Matter

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•  Heavy neutrinos decay out of equilibrium in early universe

Simple estimation

2 4 6 8 10

0.2

0.4

0.6

0.8

✓MX

�M

◆>> 1 (79)

gX << 1 (80)

U↵N ⇠ mD

MN

(81)

U↵N ⇠r

vL

vR

� m⌫

MN

(82)

+⇣NR, NR

⌘(83)

�L =

✓�+

p2 �+

�0 ��+

p2

◆(84)

mL ⇠ ghL h�0

Li (85)

mN ⇠ ghR h�0

Ri (86)

�N ⌘ �(NR ! `H) + �(NR ! ¯H⇤) =|h|28⇡

MN (87)

�N(z) =K

1

(z)

K2

(z)�N (88)

H(T ) ⇠ 1.66 g⇤T 2

MP

(89)

�(`H ! NR)

MN

(90)

H(T )

MN

(91)

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ΓN (z

) / Γ

N

z = MN / T

ΓN < H(T=MN )~

Neutrinos and the Origin of Matter

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•  Heavy neutrinos decay out of equilibrium in early universe

Simple estimation

Lmass

=�

⌫L NCR

� ✓0 mD

mD MN

◆ ✓⌫L

NR

◆(37)

m1

⇡ m2

D

MN

(38)

m2

⇡ MN (39)

Lmass

=�

⌫L NCR

� ✓0 mD

mD MN

◆ ✓⌫L

NR

◆+ mL⌫C

L ⌫L (40)

Lmass

=�

⌫L NR NCS

�0

@0 mL

D 0mL

D 0 MRD

0 MRD µ

1

A

0

@⌫L

NR

NS

1

A (41)

m⌫ ⇠ mLD

�MR

D

��1

µ�MR

D

��1

mLD (42)

�(N ! `H) 6= �(N ! ¯H⇤) (43)

Lmass

= yLHNR + h.c. + MNNCR NR (44)

Lmass

=y

⇤LcHHT L + h.c. (45)

�(NR ! `H) 6= �(NR ! ¯H⇤) (46)

m⌫ =m2

D

MR

(47)

hp0| JEM

µ |pi = U(p0)

F

1

�µ +iF

2

2M�µ⌫q

⌫ +iF

3

2M�µ⌫�5

q⌫ +FA

M2

(q2�µ � 6qqµ)�5

�U(p) (48)

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m⇤ = 8⇡ ⇤ (1.66g⇤)v2

MP

(92)

8

~ few x 10-3 eV

m⇤ = 8⇡ ⇤ (1.66g⇤)v2

MP

(92)

m1

⇡ m⇤ (93)

8

ΓN < H(T=MN )~

Neutrinos and the Origin of Matter

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•  Heavy neutrinos decay out of equilibrium in early universe

Washout processes

NR

H * H

l l _

ΔL = 2

Neutrinos and the Origin of Matter

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•  Heavy neutrinos decay out of equilibrium in early universe

Complete calculation: Boltzmann equations

di Bari ‘12

Non-Eq: T < mN

Eq: T > mN

Neutrinos and the Origin of Matter

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m2 ⇡MN (37)

�(N ! `H) 6= �(N ! ¯`H⇤) (38)

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•  Heavy neutrinos decay out of equilibrium in early universe

•  Majorana neutrinos can decay to particles and antiparticles

•  Rates can be slightly different (CP violation)

•  Resulting excess of leptons over anti-leptons partially converted into excess of quarks over anti-quarks by Standard Model sphalerons

Neutrinos and the Origin of Matter

26

m2 ⇡MN (37)

�(N ! `H) 6= �(N ! ¯`H⇤) (38)

4

•  Heavy neutrinos decay out of equilibrium in early universe

•  Majorana neutrinos can decay to particles and antiparticles

•  Rates can be slightly different (CP violation)

•  Resulting excess of leptons over anti-leptons partially converted into excess of quarks over anti-quarks by Standard Model sphalerons

Neutrinos and the Origin of Matter

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CPV Asymmetry

Tree-level CPV One-loop “absoprtive part” X

Buchmuller, Peccei, Yanagida ‘05

Neutrinos and the Origin of Matter

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CPV Asymmetry

Tree-level CPV One-loop “absoprtive part” X

Buchmuller, Peccei, Yanagida ‘05

CPV phases but not same as φPMNS

Neutrinos and the Origin of Matter

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Putting pieces together: B-L asymmetry

Buchmuller, Peccei, Yanagida ‘05

Neutrinos and the Origin of Matter

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m2 ⇡MN (37)

�(N ! `H) 6= �(N ! ¯`H⇤) (38)

4

•  Heavy neutrinos decay out of equilibrium in early universe

•  Majorana neutrinos can decay to particles and antiparticles

•  Rates can be slightly different (CP violation)

•  Resulting excess of leptons over anti-leptons partially converted into excess of quarks over anti-quarks by Standard Model sphalerons

Electroweak Sphalerons

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Aλ

Sphaleron Configuration

Electroweak Sphalerons

32

Aλ

Sphaleron Configuration Δ (B+L) / NFAnomaly

Electroweak Sphalerons

33

Aλ

Sphaleron Configuration Δ (B+L) / NFAnomaly

EW sphalerons convert B-L asymmetry to YB

Davidson-Ibarra Bound

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m⇤ = 8⇡ ⇤ (1.66g⇤)v2

MP

(92)

m1

⇡ m⇤ (93)

1

T1/2

= G0⌫(E,Z) |M0⌫ | |hm��i|2 (94)

Lfs

/ m�1/2

⌫ (95)

|✏1

| <⇠3

8⇡

MN1

m⌫3

hH0i2 (96)

8

MN1 > 109 GeV ~

Davidson, Ibarra ‘02

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TeV Scale LNV ?

€

e−

€

e−

€

A Z,N( )

€

A Z − 2,N + 2( )

TeV LNV Mechanism

Dirac Majorana

O5 =

��H

⇤

�� H†H (25)

M⌃± �M⌃0 ⇠ ↵

4⇡MW (26)

L =

g

2

hij

⇥¯LCi"�LLj

⇤+ (L$ R) + h.c. (27)

�����Qe

W

QeW

���� = 0.14

|hee|2(M�/1 TeV)

2 (28)

|Vud|2 + |Vus|2 = |Vud|21 +

|Vus|2|Vud|2

�(29)

Lmass = y ¯L ˜H⌫R + h.c. (30)

Lmass =

y

⇤

¯Lc˜H ˜HT L + h.c. (31)

3

O5 =

��H

⇤

�� H†H (25)

M⌃± �M⌃0 ⇠ ↵

4⇡MW (26)

L =

g

2

hij

⇥¯LCi"�LLj

⇤+ (L$ R) + h.c. (27)

�����Qe

W

QeW

���� = 0.14

|hee|2(M�/1 TeV)

2 (28)

|Vud|2 + |Vus|2 = |Vud|21 +

|Vus|2|Vud|2

�(29)

Lmass = y ¯L ˜H⌫R + h.c. (30)

Lmass =

y

⇤

¯LcHHT L + h.c. (31)

�(⌫R ! `H) 6= �(⌫R ! ¯`H⇤) (32)

m⌫ =

m2D

MR

(33)

3

33

F

B B

O(1) for Λ ~ 1 TeV

Implications

TeV LNV & Leptogenesis E

nerg

y S

cale

(GeV

)

1012

10 3

10 2 10-1

Standard thermal lepto

Fast ΔL = 2 int: erase L

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Deppisch et al ‘14, ‘15

TeV LNV & Leptogenesis E

nerg

y S

cale

(GeV

)

1012

10 3

10 2 10-1

Standard thermal lepto

Electroweak, resonant lepto, WIMPY baryo, ARS lepto…

Post-sphaleron, cold…

Baryogenesis alternatives 37

Fast ΔL = 2 int: erase L Deppisch et al ‘14, ‘15

38

Low Scale “ARS” Leptogenesis

Akhmedov, Rubakov, Smirmov ‘98

1.  3 Singlet RH neutrinos: NA , NB , NC

2.  LTOT = LSM + LA + LB + LC

3.  Nk oscillations + CPV ! LA = 0, LA = 0, LA = 0 but LTOT =0

4.  Yukawa interactions: Lk , H + lk in equilibrium above TEW for k=A,B but not for k=C

5.  Lepton number for lA,B converted to nB by EW sphalerons

6.  Conditions 4 ! MNk can be ~ O( GeV )

/ / /

39

Low Scale “ARS” Leptogenesis

M. Drewes

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II. Neutrino Mass from Cosmology

41

ACFI Workshop

December 2015

42

0νββ-Decay: Standard MechanismThree active light neutrinos

Effe

ctiv

e D

BD

neu

trino

mas

s (e

V)

Inverted Normal

Lightest neutrino mass (eV) !

43

0νββ-Decay: Standard Mechanism Three active light neutrinos

Effe

ctiv

e D

BD

neu

trino

mas

s (e

V)

Inverted Normal

Current generation Current generation

Ton Scale

Lightest neutrino mass (eV) !

44

0νββ-Decay: Standard Mechanism Three active light neutrinos

Effe

ctiv

e D

BD

neu

trino

mas

s (e

V)

Inverted Normal

Ton Scale

Full implications require information on lightest mass & hierarchy

Lightest neutrino mass (eV) !

Current generation Current generation

45

Interpreting a Positive Result Three active light neutrinos

Effe

ctiv

e D

BD

neu

trino

mas

s (e

V)

Inverted Normal

Ton Scale

Positive result would be consistent with 3 light active ν’s & IH or quasi-deg regime, but not definitive as to mechanism

Lightest neutrino mass (eV) !

Current generation Current generation

46

Interpreting a Null Result: St’d Mechanism Three active light neutrinos

Effe

ctiv

e D

BD

neu

trino

mas

s (e

V)

Inverted Normal

Ton Scale

Full implications require information on lightest mass & hierarchy

Lightest neutrino mass (eV) !

Current generation Current generation

47

Kinematic Neutrino Mass Measurements

KATRIN 3H ! 3He e- ν _

48

St’d Mech: What Would a Null Result Imply ? Three active light neutrinos

Effe

ctiv

e D

BD

neu

trino

mas

s (e

V)

Inverted Normal

Ton Scale

3H decay cur gen

Null result in NLDBD & non-zero mν from 3H decay ! Neutrinos are (pseudo) Dirac

Lightest neutrino mass (eV) !

Current generation Current generation

49

St’d Mech: What Would a Null Result Imply ? Three active light neutrinos

Lightest neutrino mass (eV) !

Effe

ctiv

e D

BD

neu

trino

mas

s (e

V)

Inverted

Ton Scale

3H decay cur gen

Normal

3H decay next gen

Current generation Current generation

Null result in NLDBD & non-zero mν from 3H decay ! Neutrinos are (pseudo) Dirac

50

St’d Mech: What Would a Null Result Imply ? Three active light neutrinos

Lightest neutrino mass (eV) !

Effe

ctiv

e D

BD

neu

trino

mas

s (e

V)

Inverted

Ton Scale

Normal

Current generation Current generation

Null result in NLDBD & non-zero mν from 3H decay ! Neutrinos are (pseudo) Dirac

3H decay cur gen

3H decay next gen

P. Vogel

51

Neutrino Mass & Cosmology

Matter Power Spectrum

Transition to non-rel ν matter

Massive neutrinos suppress power (relative to large scale power) at scales below free streaming scale K. Abazajian ACFI neutrino mass workshop

Σ mv < 0.12 eV

52

Neutrino Mass & Cosmology

Matter Power Spectrum

K. Abazajian ACFI neutrino mass workshop

J. Brau, U. Oregon

Later Earlier

53

Neutrino Mass & Cosmology

Matter Power Spectrum

K. Abazajian ACFI neutrino mass workshop

Later Earlier

Neutrino Free Streaming

ΩM = Ων + ΩDM + ΩB δρν δρDM

Free Streaming Scale

m⇤ = 8⇡ ⇤ (1.66g⇤)v2

MP

(92)

m1

⇡ m⇤ (93)

1

T1/2

= G0⌫(E,Z) |M0⌫ | |hm��i|2 (94)

Lfs

/ m�1/2

⌫ (95)

8

54

Neutrino Mass & Cosmology

Matter Power Spectrum

K. Abazajian ACFI neutrino mass workshop

Later Earlier

Neutrino Free Streaming

ΩM = Ων + ΩDM + ΩB δρν δρDM

Free Streaming Scale

m⇤ = 8⇡ ⇤ (1.66g⇤)v2

MP

(92)

m1

⇡ m⇤ (93)

1

T1/2

= G0⌫(E,Z) |M0⌫ | |hm��i|2 (94)

Lfs

/ m�1/2

⌫ (95)

8

δρν (power) suppressed for L < Lfs

55

Neutrino Mass & Cosmology

Matter Power Spectrum

K. Abazajian ACFI neutrino mass workshop

Later Earlier

Neutrino Free Streaming

ΩM = Ων + ΩDM + ΩB δρν δρDM

Free Streaming Scale

m⇤ = 8⇡ ⇤ (1.66g⇤)v2

MP

(92)

m1

⇡ m⇤ (93)

1

T1/2

= G0⌫(E,Z) |M0⌫ | |hm��i|2 (94)

Lfs

/ m�1/2

⌫ (95)

8

δρν (power) suppressed for L < Lfs

Suppression moves to smaller scales ! Larger k

Increase mν

56

Neutrino Mass & Cosmology

Matter Power Spectrum

K. Abazajian ACFI neutrino mass workshop

Neutrino Free Streaming

ΩM = Ων + ΩDM + ΩB δρν δρDM

Free Streaming Scale

m⇤ = 8⇡ ⇤ (1.66g⇤)v2

MP

(92)

m1

⇡ m⇤ (93)

1

T1/2

= G0⌫(E,Z) |M0⌫ | |hm��i|2 (94)

Lfs

/ m�1/2

⌫ (95)

8

δρν (power) suppressed for L < Lfs

Suppression moves to smaller scales ! Larger k

Increase mν

Later Earlier

Increase mν

Σ mv < 0.12 eV Palanque-Dalabrouille ‘15

57

St’d Mech: What Would a Null Result Imply ? Three active light neutrinos

Lightest neutrino mass (eV) !

Effe

ctiv

e D

BD

neu

trino

mas

s (e

V)

Inverted

Ton Scale

3H decay cur gen

Null result in NLDBD & non-zero mν from cosmology ! Conclusion depends on mlightest & hierarchy

Normal

3H decay next gen

Cosmo current

Current generation Current generation

58

St’d Mech: What Would a Null Result Imply ? Three active light neutrinos

Lightest neutrino mass (eV) !

Effe

ctiv

e D

BD

neu

trino

mas

s (e

V)

Inverted

Ton Scale

3H decay cur gen

Null result in NLDBD & non-zero mν from cosmology ! Conclusion depends on mlightest & hierarchy

Normal

Current generation Current generation

Cosmo current

3H decay next gen

P. Vogel

59

Lecture VIII Summary •  Simplest type I see-saw mechanism with Majorana 3 NR + CPV

provides ingredients for baryogenesis via thermal leptogenesis

•  “Standard leptogenesis” ! MN1 > 109 GeV

•  Observation of 0νββ-decay consistent with “standard mechanism” would demonstrate existence of one key ingredient for thermal leptogenesis

•  Discovery of TeV scale (and below) LNV (0νββ-decay + LHC…) would preclude high scale leptogenesis & point to alternate, low-scale scenarios (ARS lepto, EW baryo…)

•  Precision cosmology (large scale structure, CMB) places tight constraints on Σmν for the three light active neutrinos, squeezing the viability of the IH region for mββ

•  Challenge for theory: are there any well-motivated loopholes to cosmological constraints ?