Lecture II: Neutrino Mass Models in Context M.J. Ramsey-Musolf U - - PowerPoint PPT Presentation
Lecture II: Neutrino Mass Models in Context M.J. Ramsey-Musolf U Mass Amherst http://www.physics.umass.edu/acfi/ ACFI NLDBD School 10/31-11/3 2017 1 Lecture II Goals Provide broader BSM context for 0 decay Provide a simple
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Lecture II: Neutrino Mass Models in Context
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 II Goals
models with example illustrations
searches
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Lecture II Outline
I. The BSM Context II. 0νββ-decay: General Considerations III. Neutrino Mass Models IV. Implications for 0νββ-decay
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Fundamental Questions
MUST answer SHOULD answer
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Fundamental Questions
MUST answer SHOULD answer
H 0 H 0 ϕNEW
Δ m2 ~ λ Λ2
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θQCD , parity, unification...
Fundamental Questions
MUST answer SHOULD answer
H 0 H 0 ϕNEW
Δ m2 ~ λ Λ2
Origin of mν
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θQCD , parity, unification...
flavor…
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Naturalness Problem
Scalar Fields in Particle Physics
Scalar Fields in Particle Physics
Scalar fields are a simple Discovery of a (probably) fundamental 125 GeV scalar : Scalar fields are theoretically problematic
H 0 H 0 ϕNEW
Δ m2 ~ λ Λ2 Is it telling us anything about Λ ? Naturalness?
Scalar Fields in Particle Physics
Scalar fields are a simple Discovery of a (probably) fundamental 125 GeV scalar : Scalar fields are theoretically problematic
H 0 H 0 ϕNEW
Δ m2 ~ λ Λ2 mh
2 ~ λ v2 & GF ~ 1/v2 : what keeps GF “large” ?
LHC Implications
challenging for the hadronic collider
(cosmological constant???)
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
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Neutrino Masses
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Neutrino Masses
Partners Partners
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Neutrino Masses
Partners Partners
Higgs Mechanism
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Neutrino Masses
Partners Partners
Higgs Mechanism Something else ?
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Neutrino Masses
Partners Partners
New heavy neutrino-like particle = its own anti-particle “See saw mechanism”
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Neutrino Masses
Partners Partners
New heavy neutrino-like particle = its own anti-particle “See saw mechanism”
m2 ⇡ MN
~ 1012 – 1015 GeV
D
MN
~ eV Physical state masses
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Neutrino Masses
Partners Partners
New heavy neutrino-like particle = its own anti-particle “See saw mechanism” “Leptogenesis” Heavy neutrino decays in early universe generate baryon asym
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BSM Physics: Where Does it Live ?
Mass Scale Coupling MW
BSM ? BSM ?
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BSM Physics: Where Does it Live ?
Mass Scale Coupling MW
BSM ?
SUSY, see-saw, BSM Higgs sector…
BSM ?
Sterile ν’s, axions, dark U(1)…
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BSM Physics: Where Does it Live ?
Mass Scale Coupling MW
BSM ?
SUSY, see-saw, BSM Higgs sector…
BSM ?
Sterile ν’s, axions, dark U(1)…
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What Questions Does It Address ?
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What Questions Does It Address ?
New heavy neutrino-like particle = its own anti-particle “See saw mechanism” “Leptogenesis” Heavy neutrino decays in early universe generate baryon asym
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What Questions Does It Address ?
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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Γ(N ! `H) 6= Γ(N ! ¯ `H∗) (
in early universe
and antiparticles
partially converted into excess of quarks over anti-quarks by Standard Model sphalerons
Neutrinos and the Origin of Matter
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Γ(N ! `H) 6= Γ(N ! ¯ `H∗) (
in early universe
and antiparticles
partially converted into excess of quarks over anti-quarks by Standard Model sphalerons
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What Questions Does It Address ?
New heavy neutrino-like particle = its own anti-particle “See saw mechanism”
m2 ⇡ MN
~ 1012 – 1015 GeV
D
MN
~ eV Physical state masses
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“νSM”, “νMSSM” LRSM LRSM MSSM + combinations & many other examples GUTs
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0νβ νββ-Decay: LNV? Mass Term?
Dirac Majorana
Lmass = y ¯ L ˜ HνR + h.c. Lmass = y Λ ¯ LcHHTL + h.c.
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Neutrino Mass Models
“νSM”, “νMSSM” LRSM LRSM MSSM + combinations & many other examples GUTs
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0νβ νββ-Decay: Type I See-Saw
Dirac Majorana
Lmass = y ¯ L ˜ HνR + h.c. Lmass = y Λ ¯ LcHHTL + h.c.
¯ ⌫L ¯ N C
R
✓ mD mD MN ◆ ✓ ⌫L NR ◆
One generation: SM + one NR
Lmass = y ¯ L ˜ HNR + h.c. + MN ¯ N C
R NR
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0νβ νββ-Decay: Type I See-Saw
Dirac Majorana
Lmass = y ¯ L ˜ HνR + h.c. Lmass = y Λ ¯ LcHHTL + h.c.
¯ ⌫L ¯ N C
R
✓ mD mD MN ◆ ✓ ⌫L NR ◆
One generation: SM + one NR
Lmass = y ¯ L ˜ HNR + h.c. + MN ¯ N C
R NR
Lepton number violating
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0νβ νββ-Decay: Type I See-Saw
Dirac Majorana
Lmass = y ¯ L ˜ HνR + h.c. Lmass = y Λ ¯ LcHHTL + h.c.
¯ ⌫L ¯ N C
R
✓ mD mD MN ◆ ✓ ⌫L NR ◆
One generation: SM + one NR
Lmass = y ¯ L ˜ HNR + h.c. + MN ¯ N C
R NR
Lepton number violating Eigenvalues m1 ⇡ m2
D
MN
m2 ⇡ MN
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0νβ νββ-Decay: Type I See-Saw
Dirac Majorana
Lmass = y ¯ L ˜ HνR + h.c. Lmass = y Λ ¯ LcHHTL + h.c.
νL νL NR
H H
Low-energy eff theory
Λ = mN
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0νβ νββ-Decay: Type I See-Saw
Dirac Majorana
Lmass = y ¯ L ˜ HνR + h.c. Lmass = y Λ ¯ LcHHTL + h.c.
+ ⇣ NR, ˜ NR ⌘
“ν MSM” “ν MSSM”
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Neutrino Mass Models
“νSM”, “νMSSM” LRSM LRSM MSSM + combinations & many other examples GUTs
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0νβ νββ-Decay: Type II See-Saw
Dirac Majorana
Lmass = y ¯ L ˜ HνR + h.c. Lmass = y Λ ¯ LcHHTL + h.c.
⇣ ⌘ ∆L = ✓ ∆+√ 2 ∆+ ∆0 −∆+√ 2 ◆
Introduce “Complex Triplet”: ΔL ~ (1, 3, 2) Lepton number violating Δ0 vev ! Majorana mν
⇥ ⇤ L = g 2hij ⇥¯ LCi"∆LLj⇤ + h.c.
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Left-Right Symmetric Model
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BSM Mass Scale
Energy Scale Parity Breaking Scale ~ MW
R ?
Weak Scale ~ MW
L
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Left-Right Symmetric Model
Energy Scale Parity Breaking Scale ~ MW
R ?
Weak Scale ~ MW
L
SU(2)L x SU(2)R x U(1)B-L
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Energy Scale Parity Breaking Scale ~ MW
R ?
Weak Scale ~ MW
L
SU(2)L x SU(2)R x U(1)B-L
See-saw scale ?
Left-Right Symmetric Model
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Left-Right Symmetric Model
Gauge boson mass eigenstates CKM Matrices for LH & RH sectors: quarks V L
CKM = S† uSd
V R
CKM = T † uTd
uI
Li = (Su)ij umass Lj
uI
Ri = (Tu)ij umass Rj
dI
Li = (Sd)ij dmass Lj
dI
Ri = (Td)ij dmass Rj
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Left-Right Symmetric Model
Gauge boson mass eigenstates PMNS Matrices for LH & RH sectors: leptons ⌫I
Li = (S⌫)ij ⌫diag Lj
N I
Ri = (TN)ij N diag Rj
`I
Li = (S`)ij `diag Lj
`I
Ri = (T`)ij `diag Rj
V L
PMNS = S† ⌫S`
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Left-Right Symmetric Model
Two sources of mν :
L = g 2hij ⇥¯ LCi"∆LLj⇤ + (L $ R) + h.c.
Lmass = ¯ ⌫L ¯ N C
R
✓ mD mD MN ◆ ✓ ⌫L NR ◆ + mL¯ ⌫C
L ⌫L
mL ⇠ ghL h∆0
Li
mN ⇠ ghR h∆0
Ri
Type I see-saw Type II see-saw
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Neutrino Mass Models
“νSM”, “νMSSM” LRSM LRSM MSSM + combinations & many other examples GUTs
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0νβ νββ-Decay: Type III See-Saw
Dirac Majorana
Lmass = y ¯ L ˜ HνR + h.c. Lmass = y Λ ¯ LcHHTL + h.c.
Introduce “Fermionic Triplet”: ΔL ~ (1, 3, 0) Like Type I but NR ! ρL See P. Fileviez Perez, 1501.01886
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Neutrino Mass Models
“νSM”, “νMSSM” LRSM LRSM MSSM + combinations & many other examples GUTs
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0νβ νββ-Decay: Inverse See-Saw
Dirac Majorana
Lmass = y ¯ L ˜ HνR + h.c. Lmass = y Λ ¯ LcHHTL + h.c.
Introduce “singlet” Majorana neutrino Singlet Majorana mass Lmass = ¯ ⌫L ¯ NR ¯ N C
S
mL
D
mL
D
M R
D
M R
D
µ 1 A @ ⌫L NR NS 1 A
mν ⇠ mL
D
D
1 µ
D
1 mL
D
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Neutrino Mass Models
“νSM”, “νMSSM” LRSM LRSM MSSM + combinations & many other examples GUTs
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0νβ νββ-Decay: Type II See-Saw
Dirac Majorana
Lmass = y ¯ L ˜ HνR + h.c. Lmass = y Λ ¯ LcHHTL + h.c.
Introduce new scalars (S) & Majorana fermions (F): “mediators” S ν ν F Attach Higgs lines as appropriate to get Weinberg operator Recent mini-review: H. Sugiyama, 1505.01738
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0νβ νββ-Decay: Type II See-Saw
Dirac Majorana
Lmass = y ¯ L ˜ HνR + h.c. Lmass = y Λ ¯ LcHHTL + h.c.
Introduce new scalars (S) & Majorana fermions (F): “mediators” “Zee Model” Recent mini-review: H. Sugiyama, 1505.01738
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0νβ νββ-Decay: Type II See-Saw
Dirac Majorana
Lmass = y ¯ L ˜ HνR + h.c. Lmass = y Λ ¯ LcHHTL + h.c.
SUSY with “R parity” violation
PR = (-1)2S+3(B-L)
“Superpotential”
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0νβ νββ-Decay: LNV? Mass Term?
e− e−
A Z,N
( )
A Z − 2,N + 2
( )
Impact of observation
Dirac Majorana
Lmass = y ¯ L ˜ HνR + h.c. Lmass = y Λ ¯ LcHHTL + h.c.
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conserved at classical level
baryogenesis via leptogenesis
LNV Physics
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0νβ νββ-Decay: LNV? Mass Term?
e− e−
A Z,N
( )
A Z − 2,N + 2
( )
Impact of observation
Dirac Majorana
Lmass = y ¯ L ˜ HνR + h.c. Lmass = y Λ ¯ LcHHTL + h.c.
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conserved at classical level
baryogenesis via leptogenesis
LNV Physics What’s inside ?
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BSM Physics: Where Does it Live ?
Mass Scale Coupling MW
BSM ?
SUSY, see-saw, BSM Higgs sector…
BSM ?
Sterile ν’s, axions, dark U(1)…
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BSM Physics: Where Does it Live ?
Mass Scale Coupling MW
BSM ?
SUSY, see-saw, BSM Higgs sector…
BSM ?
Sterile ν’s, axions, dark U(1)…
Is the mass scale associated with mν far above MW ? Near MW ? Well below MW ?
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LNV Mass Scale & 0νβ νββ-Decay
A(Z,N) ! ! A(Z+2, N-2) + e- e-
Underlying Physics
mass at the very high see-saw scale
neutrino mass
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LNV Mass Scale & 0νβ νββ-Decay
A(Z,N) ! ! A(Z+2, N-2) + e- e-
Underlying Physics
mass at the very high see-saw scale
neutrino mass
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0νβ νββ-Decay: LNV? Mass Term?
Dirac Majorana
Lmass = y ¯ L ˜ HνR + h.c. Lmass = y Λ ¯ LcHHTL + h.c.
νL νL NR
H H
Low-energy eff theory
Λ = mN
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0νβ νββ-Decay: LNV? Mass Term?
e− e− ν M
W − W − A Z,N
( )
A Z − 2,N + 2
( )
“Standard” Mechanism
Dirac Majorana
Lmass = y ¯ L ˜ HνR + h.c. Lmass = y Λ ¯ LcHHTL + h.c.
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at the conventional see-saw scale: Λ ~ 1012 – 1015 GeV
mediate decay process
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Three Light Neutrinos: What Do We Know ?
A(Z,N) ! A(Z+2, N-2) + e- e- ν ν 2ν DBD: A(Z,N) ! A(Z+2, N-2) + e- e- 0ν DBD:
If own antiparticle, can be emitted then absorbed during decay
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Three Light Neutrinos: What Do We Know ?
A(Z,N) ! A(Z+2, N-2) + e- e- ν ν 2ν DBD: A(Z,N) ! A(Z+2, N-2) + e- e- 0ν DBD:
If own antiparticle, can be emitted then absorbed during decay All three light neutrinos participate ! Rate governed by an effective mass
Im Re m m m
ee ee ee (1) (3) (2)| | | | | | e
e . .
ee<m > 2iβ 2iα Individual contributions
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Why Might A “Ton-Scale” Exp’t See It?
Three active light neutrinos
Effective DBD neutrino mass (eV)
Inverted Normal
Lightest neutrino mass (eV) !
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LNV Mass Scale & 0νβ νββ-Decay
A(Z,N) ! ! A(Z+2, N-2) + e- e-
Underlying Physics
mass at the very high see-saw scale
neutrino mass
Two parameters: Effective coupling & effective heavy particle mass
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0νβ νββ-Decay: LNV? Mass Term?
e− e−
A Z,N
( )
A Z − 2,N + 2
( )
TeV LNV Mechanism
Dirac Majorana
Lmass = y ¯ L ˜ HνR + h.c. Lmass = y Λ ¯ LcHHTL + h.c.
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F S S
the TeV scale
accessible with tonne-scale exp’ts due to heavy Majorana particle exchange
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0νβ νββ-Decay: LNV? Mass Term?
e− e−
TeV LNV Mechanism
Dirac Majorana
Lmass = y ¯ L ˜ HνR + h.c. Lmass = y Λ ¯ LcHHTL + h.c.
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NR WR WR
the TeV scale
accessible with tonne-scale exp’ts due to heavy Majorana particle exchange
A(Z+2, N-2) A(Z, N)
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0νβ νββ-Decay: LNV? Mass Term?
e− e−
TeV LNV Mechanism
Dirac Majorana
Lmass = y ¯ L ˜ HνR + h.c. Lmass = y Λ ¯ LcHHTL + h.c.
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the TeV scale
accessible with tonne-scale exp’ts due to heavy Majorana particle exchange W e e ~ ~ ~
A(Z+2, N-2) A(Z, N)
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0νβ νββ-Decay: LNV? Mass Term?
e− e−
A Z,N
( )
A Z − 2,N + 2
( )
TeV LNV Mechanism
Dirac Majorana
Lmass = y ¯ L ˜ HνR + h.c. Lmass = y Λ ¯ LcHHTL + h.c.
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F B B O(1) for Λ ~ 1 TeV
0νβ νββ-Decay: TeV Scale LNV
General Classification: Helo et al, PRD 88.011901, 88.073011 Dirac Majorana
Lmass = y ¯ L ˜ HνR + h.c. Lmass = y Λ ¯ LcHHTL + h.c.
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0νβ νββ-Decay: TeV Scale LNV
General Classification: Helo et al, PRD 88.011901, 88.073011 Dirac Majorana
Lmass = y ¯ L ˜ HνR + h.c. Lmass = y Λ ¯ LcHHTL + h.c.
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νSM: Type I See-Saw
WL WL NR e e
Mass: standard see-saw but TeV scale
0νβ νββ-Decay: TeV Scale LNV
Light + heavy Majorana ν contributions: Single heavy flavor Dirac Majorana
Lmass = y ¯ L ˜ HνR + h.c. Lmass = y Λ ¯ LcHHTL + h.c.
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Type I see-saw: M11 = 0
Since p2 < 0 ! Amplitude reduction !
Mitra et al, 2012
0νβ νββ-Decay: TeV Scale LNV
Dirac Majorana
Lmass = y ¯ L ˜ HνR + h.c. Lmass = y Λ ¯ LcHHTL + h.c.
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LRSM: Type I See-Saw
WR WR NR e e
Mass: standard see-saw but TeV scale
NR
0νβ νββ-Decay: TeV Scale LNV
Dirac Majorana
Lmass = y ¯ L ˜ HνR + h.c. Lmass = y Λ ¯ LcHHTL + h.c.
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LRSM: Type I See-Saw
WR WR NR e e
Mass: standard see-saw but TeV scale
NR ν + NR
Tello et al, 1011.3522
0νβ νββ-Decay: TeV Scale LNV
General Classification: Helo et al, PRD 88.011901, 88.073011 Dirac Majorana
Lmass = y ¯ L ˜ HνR + h.c. Lmass = y Λ ¯ LcHHTL + h.c.
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SUSY: R Parity-Violation
Sfermion Gaugino q , l ~ ~ g , χ ~
u u d d e e
V ~ F ~ F ~ Majorana
LNV
0νβ νββ-Decay: TeV Scale LNV
General Classification: Helo et al, PRD 88.011901, 88.073011 Dirac Majorana
Lmass = y ¯ L ˜ HνR + h.c. Lmass = y Λ ¯ LcHHTL + h.c.
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SUSY: R Parity-Violation
u u d d e e
V ~ F ~ F ~
LNV
0νβ νββ-Decay: TeV Scale LNV
General Classification: Helo et al, PRD 88.011901, 88.073011 Dirac Majorana
Lmass = y ¯ L ˜ HνR + h.c. Lmass = y Λ ¯ LcHHTL + h.c.
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SUSY: R Parity-Violation
u u d d e e
V ~ F ~ F ~
LNV
0νβ νββ-Decay: TeV Scale LNV
General Classification: Helo et al, PRD 88.011901, 88.073011 Dirac Majorana
Lmass = y ¯ L ˜ HνR + h.c. Lmass = y Λ ¯ LcHHTL + h.c.
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SUSY: R Parity-Violation
u u d d e e
V ~ F ~ F ~
LNV
0νβ νββ-Decay: TeV Scale LNV
General Classification: Helo et al, PRD 88.011901, 88.073011 Dirac Majorana
Lmass = y ¯ L ˜ HνR + h.c. Lmass = y Λ ¯ LcHHTL + h.c.
L = g 2hij ⇥¯ LCiε∆LLj⇤ + (L ↔ R) + h.c.
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WR WR ΔR e e
LRSM: Type II See-Saw
0νβ νββ-Decay: TeV Scale LNV
General Classification: Helo et al, PRD 88.011901, 88.073011 Dirac Majorana
Lmass = y ¯ L ˜ HνR + h.c. Lmass = y Λ ¯ LcHHTL + h.c.
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Scalar Leptoquarks
Mass: like RPV SUSY (loop) NLDBD: need Majorana fermion
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LNV Mass Scale & 0νβ νββ-Decay
A(Z,N) ! ! A(Z+2, N-2) + e- e-
Underlying Physics
mass at the very high see-saw scale
neutrino mass
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LNV Mass Scale & 0νβ νββ-Decay
Effective DBD neutrino mass (eV) ! Lightest neutrino mass (eV) !
3 light ν’s 3 + 1 light ν’s 3 light ν’s 3 + 1 light ν’s
Ton Scale
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Sterile Neutrinos & 0νββ-Decay
3 active light neutrinos
Effective DBD neutrino mass (eV) Lightest neutrino mass (eV) ! Giunti & Zavanin, JHEP07 (2015) 171
3+1 active light neutrinos
Lightest neutrino mass (eV) !
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Sterile Neutrinos & 0νββ-Decay
3 active light neutrinos
Effective DBD neutrino mass (eV) Lightest neutrino mass (eV) ! Giunti & Zavanin, JHEP07 (2015) 171
3+1 active light neutrinos
Lightest neutrino mass (eV) !
0νβ νββ-Decay: Rate & Mass Dependence
Dirac Majorana
Lmass = y ¯ L ˜ HνR + h.c. Lmass = y Λ ¯ LcHHTL + h.c.
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Light ν exchange
Quadratic dependence on mββ
NR
Heavy particle exchange
1 T1/2 = G0ν(E, Z) |M0ν| |hmββi|2
Scales as 1 / M10
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Lecture II Summary
fundamental interaction physics
address it with sensitivities to a variety of BSM mass scales
problems, such as the origin of the matter-antimatter asymmetry
and go well beyond the simplest “standard mechanism” expectations