m. nemevsek - neutrino mass and the lhc
DESCRIPTION
The SEENET-MTP Workshop BW2011Particle Physics from TeV to Plank Scale28 August – 1 September 2011, Donji Milanovac, SerbiaTRANSCRIPT
Neutrino mass and the LHC
ICTP, Trieste
Miha Nemevšek
Balkan Workshop 2011, Donji Milanovac
with Maiezza, Melfo, Nesti, Senjanović, Tello, Vissani and Zhang
LHC a neutrino machine?
Neutrino mass is an experimentallyestablished fact for BSM physics.
Might as well be @ TeV (hierarchy)
A phenomenological hint may already be here
Neutrino mass and BSM
!m
2
S,A & !A,S,13
Facts Questions
Mass scale & hierarchy
CP phases
Dirac or MajoranaAt least two massive light
neutrinos
The theory of neutrino mass?
LHC may play a crucial role
Low-high energy interplay becomes important
Origin of
Standard Model only,
m!
!L m! = 0
Effective theory
High scale
Typical in GUTs
Indirect, LHC of little use
TeV
Theory: GUT remnant
Phenomenological
Neutrino mass and the LHC
OW = y!h!h
!! m! =
y2v2
!
UV completions of OW
I! S
h
!
h II! !
!
h h III!
T 0
h
!
h
Fermionic singlet Bosonic triplet Fermionic triplet
Renormalizable theory = seesaw scenarios
Type I+III
Triplet predicted at TeV by a minimal SU(5) with
Neutrino mass matrix through decays
Oscillations-collider connection
24F
Bajc, Senjanović ’06Bajc, MN, Senjanović ’07
UV completions of OW
I! S
h
!
h II! !
!
h h III!
T 0
h
!
h
Fermionic singlet Bosonic triplet Fermionic triplet
Type I+IIPredicted by a minimal LR symmetric theory
Singlet is gauged, type I required by anomalies
Triplet breaks the LR symmetry - type II
May need to be light !!
Left-Right symmetry
!
!L
eL
"
, WL !
!
!R
eR
"
, WR
Parity restoration at high scales
Spontaneously broken
Origin of the seesaw mechanismMinkowski ’77Senjanović ’79
Senjanović, Mohapatra ’80
Pati, Salam ’74Mohapatra, Pati ’75
Mohapatra, Senjanović ’75
Minimal LR Model
SU(2)L ! SU(2)R ! U(1)B!L
LR symmetric Higgs sector, parity invariant L
!(2, 2, 0), "L(3, 1, 2), "R(1, 3, 2)
First stage @ TeV
Breaks and Lepton numberSU(2)R
Second stage @ 100 GeV
MWR= g vR, mN = y vR
!!R" =
!
0 0
vR 0
"
!!L" # vL = 0
!!" =
!
v1 0
0 v2ei!
"
vL = ! v2/vR
MW ! v "
!
v21
+ v22, mD ! v
Mass spectra
LY = !L(Y! ! + Y! !)!R + !TL Y"L
"L!L + !TR Y"R
"R!R + h.c.
MD = v1 Y! + v2 e!i! Y!,
M" = v2 ei! Y! + v1 Y!
M!R= vR Y!R
M!L= vL Y!L
! MTD M
!1!R
MD
C : Y! = Y!T , Y"L,R
= Y"R,L
!
Dirac terms Majorana terms
Mass eigenstate basis
C : U!L = U!
!R
M! = U!L m! U†!R
, M"L= U!
"L m" U†"L
, M"R= U!
"R mN U†"R
Flavor fixed in type II:
Remember; two angles, one limit, no phases
VR!
= VL
The Interactions
Lcc =g!
2
!
!LVL† /W "L + !RVR
† /WR "R
"
New Scalar:
New Gauge:
L!++ = eTR Y !
++R
eR
Y =
g
MWR
VR!mNVR
†
Flavor fixed in type II:
Remember; two angles, one limit, no phases
VR!
= VL
The Interactions
Lcc =g!
2
!
!LVL† /W "L + !RVR
† /WR "R
"
New Scalar:
New Gauge:
L!++ = eTR Y !
++R
eR
Y =
g
MWR
VR!mNVR
†
LHC could eventually measure these
Example only!
Bounds on the LR scale
Theoretical bounds since ’81
A recent detailed study, including CP violation
Beall et al. ’81...Zhang et al. ’07
Direct searches
Dijets
Light neutrino
LHC is here!
Maiezza, Nesti, MN, Senjanović ’10
C : MWR> 2.5 TeV P : MWR
> 3.2 ! 4.2 TeV
CMS 1107.4771
CMS PAS EXO-11-024MWR> 2.27 TeV
MWR> 1.51 TeV
L ! 2.5 fb!1
Left-Right @ LHC
Most interesting channel: l l j j
LNV at colliders
p
p
WR
!i
N!
!j
WR
j
j
VRi!
VRj!
Keung, Senjanović ’83
Gauge production: s-channel,
W nearly on-shell
Clean, no missing energy
Reconstructs W and N masses
Information on the flavor
Limits from the LHC
1.64`
23
4
800 1000 1200 1400 1600 18000
200
400
600
800
1000
MWR !GeV"
MN
!!GeV
"
D0:dijets
L!33.2pb"1
1.64`
2
34
800 1000 1200 1400 1600 18000
200
400
600
800
1000
MWR !GeV"MN!!GeV
"
D0:dijets
L"34pb#1
MN, Nesti, Senjanović, Zhang ’11
High N inaccessible due to jets, low N due to isolation
This year:
Electron and muon channel essentially the same
L = 0.1(1) fb!1 : MWR> 1.6(2.2)TeV
March
Limits from the LHC
1.64`
23
4
800 1000 1200 1400 1600 18000
200
400
600
800
1000
MWR !GeV"
MN
!!GeV
"
D0:dijets
L!33.2pb"1
1.64`
2
34
800 1000 1200 1400 1600 18000
200
400
600
800
1000
MWR !GeV"MN!!GeV
"
D0:dijets
L"34pb#1
MN, Nesti, Senjanović, Zhang ’11
High N inaccessible due to jets, low N due to isolation
This year:
Electron and muon channel essentially the same
L = 0.1(1) fb!1 : MWR> 1.6(2.2)TeV
March
[GeV]RWM
800 1000 1200 1400 1600
[G
eV
]e
NM
0
200
400
600
800
1000
1200Observed
Expected
RW > MeNM
Exclu
de
d b
y T
eva
tro
n
CMS Preliminary
at 7 TeV-1240 pb
[GeV]RWM
800 1000 1200 1400 1600
[G
eV
]µ
NM
0
200
400
600
800
1000
1200Observed
Expected
RW > MµNM
Exclu
de
d b
y T
eva
tro
n
CMS Preliminary
at 7 TeV-1240 pb
July
CMS PAS EXO-11-002
Low/high energy interplay
Majorana mass term dominanceM!R
= vR Y M!L= vL Y
!
Implications for masses and mixings
mN ! m! U!R = U!
!L ! VR = V!
L
mN2
2 ! mN1
2
mN3
2 ! mN1
2=
m!2
2 ! m!1
2
m!3
2 ! m!1
2" ±0.03
mcosm =
!
!m2A
"
imNi
!
|mN3
2 ! m2N2
|,
Hierarchy probe @ LHC
Cosmo-oscillations-LHC link
lightest neutrino mass in eV
normal
inverted
|mee !
|in
eV
10!4 0.001 0.01 0.1 110!4
10!3
0.01
0.1
1.0
10!4 0.001 0.01 0.1 110!4
0.001
0.01
0.1
1
1
and cosmology0!2"
0!2"
Gerda, Cuore, Majorana,...
Majorana mass implies
Claim of observation
Vissani ’99
Review by Rodejohann ’11
|mee
!| ! 0.4 eV
Klapdor-Kleingrothaus ’06, ’09
and cosmology0!2"
lightest neutrino mass in eV
normal
inverted
|mee !
|in
eV
10!4 0.001 0.01 0.1 110!4
10!3
0.01
0.1
1.0
10!4 0.001 0.01 0.1 110!4
0.001
0.01
0.1
1
1
Cosmological bounds!
m! < 0.17 eV
!m! < 0.44 eV
Seljak et al. ’06
WMAP alone
Hannestad et al. ’10
If confirmed, a hint for NPVissani ’02
WR
New Diagrams for
!L !R
n
n
WR
p
N!
e
WR
e
p
VRe!
VRe!
n
n
W
p
W
!L
p
e
e
vL
(YL)ee
n
n
WR
p
WR
!R
p
e
e
vR
(YR)ee
0!2"
Large? Tiny Subdominant?
In agreement with cosmology?
! 1/mN ! m! ! mN
Mohapatra, Senjanović ’81
: the new contribution0!2"
c
AZX
AZ`1X A
Z`2X
WL;R
e
!; N
e
WL;R
AZX
AZ`1X A
Z`2X
WL;R WL;R
´L;R
e
eLR mixings small
sin ! < MW /MWR< 10
!3
mD ! 0
HNP = G2F VR
2ej
!
1
mN j+
2 mN j
m2!
"
M4W
M4WR
JRµJµR eRe
cR
Type II: VR!
= VL suppressed:!L m!/m! ! 1
LFV: mN/m!R< 1
The gauge contribution is dominant
LHC accessible regime
: the total contribution0!2"
Interference small
Reversed role of hierarchies
No tension with cosmology
A light
No cancellations
lightest mN in GeV
lightest neutrino mass in eV
normalinverted
MWR = 3.5 TeV
largest mN = 0.5 TeV
|mee !
+N|i
neV
1 10 100 400 500
10!4 0.001 0.01 0.1 110!3
0.01
0.1
1.0
10!4 0.001 0.01 0.1 10.001
0.0050.01
0.050.1
0.51.
1
|m!+Nee|2 !
|m!ee|2 + |mN
ee|2
mN < MWR
|M!+Nee|2 = |m!1
cos2 !12 + m!2
ei"sin
2 !12|2
+!
!
!
!
p2 M4W
M4WR
"
1
mN1
cos2 !12 +
1
mN2
ei"sin
2 !12
#!
!
!
!
2
LHC and
Suppose NP is a must for ;0!2" !13 ! 0 ! = 2("2 ! "1)
0!2"
|M!+Nee|2 = |m!1
cos2 !12 + m!2
ei"sin
2 !12|2
+!
!
!
!
p2 M4W
M4WR
"
1
mN1
cos2 !12 +
1
mN2
ei"sin
2 !12
#!
!
!
!
2
LHC and
Suppose NP is a must for ;
0.0001 0.001 0.01 0.1 15
10
20
50
100
200
500
1000
lightest neutrino mass in eV
Normal HierarchyMWR = 3.5TeV, ! = 0
mN1in
GeV
10!4 0.001 0.01 0.1 15
10
20
50
100
200
500
1000
|Mee"+N |
1.0
0.60.4
0.2
0.1
0.05
1
0.0001 0.001 0.01 0.1 15
10
20
50
100
200
500
1000
lightest neutrino mass in eV
Normal HierarchyMWR = 3.5TeV, ! = "
mN1in
GeV
10!4 0.001 0.01 0.1 15
10
20
50
100
200
500
1000
|Mee#+N |
1.0
0.60.4
0.2
0.1
0.05
1
0!2" !13 ! 0 ! = 2("2 ! "1)
jj : mN ! 50 GeV
j! : mN ! 20 GeV
/v : mN ! 20 GeV
/E : mN ! 3 ! 7 GeVLHC:
0!2"
|M!+Nee|2 = |m!1
cos2 !12 + m!2
ei"sin
2 !12|2
+!
!
!
!
p2 M4W
M4WR
"
1
mN1
cos2 !12 +
1
mN2
ei"sin
2 !12
#!
!
!
!
2
LHC and
Suppose NP is a must for ;
0.0001 0.001 0.01 0.1 15
10
20
50
100
200
500
1000
lightest neutrino mass in eV
Normal HierarchyMWR = 3.5TeV, ! = 0
mN1in
GeV
10!4 0.001 0.01 0.1 15
10
20
50
100
200
500
1000
|Mee"+N |
1.0
0.60.4
0.2
0.1
0.05
1
0.0001 0.001 0.01 0.1 15
10
20
50
100
200
500
1000
lightest neutrino mass in eV
Normal HierarchyMWR = 3.5TeV, ! = "
mN1in
GeV
10!4 0.001 0.01 0.1 15
10
20
50
100
200
500
1000
|Mee#+N |
1.0
0.60.4
0.2
0.1
0.05
1
0.0001 0.001 0.01 0.1 15
10
20
50
100
200
500
1000
lightest neutrino mass in eV
Inverted HierarchyMWR = 3.5TeV, ! = 0
mN1in
GeV
10!4 0.001 0.01 0.1 15
10
20
50
100
200
500
1000
|Mee"+N |
1.0
0.60.4
0.2
0.1
0.05
1
0.0001 0.001 0.01 0.1 15
10
20
50
100
200
500
1000
lightest neutrino mass in eV
Inverted HierarchyMWR = 3.5TeV, ! = "
mN1in
GeV
10!4 0.001 0.01 0.1 15
10
20
50
100
200
500
1000
|Mee#+N |
0.60.4
0.2
0.10.05
1
0!2" !13 ! 0 ! = 2("2 ! "1)
jj : mN ! 50 GeV
j! : mN ! 20 GeV
/v : mN ! 20 GeV
/E : mN ! 3 ! 7 GeVLHC:
0!2"
Lepton Flavor Violation
LFV rates computable: type II (or LHC)
tree
loop
log
µ
e e
!++L,R
e
Y!!
ee
Y!µe
µ
!++
!ci
e
"
!++
Y!µi Y!!
ie
N
µL eL
!L("L)
!++L
(!+L
)
N
!++L
(!+L
)
#, ZL, ZR
Y! Y!!
! ! 3!
! ! !!"
µ N ! e N
Cirigliano et al ’04
VL mN/m! VLT
VL mN/m! VL†
VL mN/m! VL†
Raidal, Santamaria ’97
Combined LFV constraints
lightest neutrino mass in eV
absolute bound from LFV
always allowed by LFV
Inverted HierarchyMWR = 3.5TeV
m/m
N!
10!4 0.001 0.01 0.1 10.01
0.05
0.1
0.5
1.0
5.0
10!4 0.001 0.01 0.1 10.01
0.05
0.1
0.5
1.
5.
1
lightest neutrino mass in eV
absolute bound from LFV
always allowed by LFV
Normal HierarchyMWR = 3.5TeV
m/m
N!
10!4 0.001 0.01 0.1 10.01
0.05
0.1
0.5
1.0
5.0
10!4 0.001 0.01 0.1 10.01
0.05
0.1
0.5
1.
5.
1
Muonic and tau channels
Varying PMNS constrains mN/m! < 1
Tello, MN, Senjanović, Vissani ’10
98.5 97.3 100118.4
136146 141 150
114
144156
313
2001 2003 2003 2004 2004 2005 2006 2008 2008 2011 2011 20110
50
100
150
200
250
300
3502001 2003 2003 2004 2004 2005 2006 2008 2008 2011 2011 2011
m!""
Opal Delphi## L3 CDF
$$CDFe&$
CDF%!0
H1e$
D0$$
CDFIIe#
D0$#
CMSApril
CMSJuly
Triplet searches
LHC
! =
!
!+/!
2 !++
!0"!+/
!
2
"
Gauge Production
Associated via
Pair-wise through
W±!±±
!!
W±!±
!0
Z!0
!0
!!, Z!+
!"
!!, Z!++
!""
Z, !!
W
GeV
! =
!
!+/!
2 !++
!0"!+/
!
2
"
Gauge Production
Associated via
Pair-wise through
W±!±±
!!
W±!±
!0
Z!0
!0
!!, Z!+
!"
!!, Z!++
!""
Z, !!
W
100 120 140 160 180 200
1.00
0.50
2.00
0.20
0.10
0.05
0.02
M! !TeV"
"!pb"
LHC @ 7 TeV
solid=LO
dashed=NLO
K-factor =1.3
red = assoc.
blue=pair.GeV
Decay Phase Diagram
Decays
a) Leptonic
b) Gauge boson
c) Cascade
D0: pair-production only, CMS degenerate mass
! ! !!
! ! V V
! ! !!V
Tiny
Large
Mass split
v!
v!
!!!!!V ! "m5/m4W
a) b) c)!!!V V !
m3!v!
2
v4
!!!!! !m!U"m"U †
v!
Decay Phase Diagram
Decays
a) Leptonic
b) Gauge boson
c) Cascade
D0: pair-production only, CMS degenerate mass
! ! !!
! ! V V
! ! !!V
Tiny
Large
Mass split
v!
v!
!!!!!V ! "m5/m4W
a) b) c)!!!V V !
m3!v!
2
v4
!!!!! !m!U"m"U †
v!
Cascade Decay
Leptonic DecayGauge
Boson Decay
10!10 10!8 10!6 10!4 0.01 1
0.51.0
5.010.0
50.0100.0
v" !GeV"
"M!GeV
"
c
Mass splits
c
The general potential
Splits components by ; there is a sum rule
V = ! m2H H†H + m2
!Tr!†! + (µHT i!2!!H + h.c.)+
"1(H†H)2 + "2(Tr!†!)2 + "3Tr(!†!)2+
# H†H Tr!†! + $ H†!!†H
v2
m2
!+ ! m2
!++ " m2
!0 ! m2
!+ " ! v2/4
mS " mA = m!0
Only two mass scales govern the spectrum up to O
!
v2
v!2
"
Electroweak Precision Tests
EWPT calculated for the first time
Oblique parameters suffice (Yukawa small by LFV)
100 200 300 400 500 600
!40
!20
0
20
40
60
80
100
mh!GeV"
#m "# !m"##$!GeV
"
m"##$200 GeV
68%95%
99%
T positive definite, controlled by mass splits
Heavy Higgs=negative T
T parameter
Bottom-line
O(10 GeV) splits allowed
Cascade region opens up...
Melfo, MN, Nesti, Senjanović, Zhang ’11
c
Type II Roadmap
Direct searchLHC 980 pb!1!v"#10!6GeV"
Sum Rule
Sum Rule &Z width
LEP
EWPTmh#300GeV
0 100 200 300 400 500 600 700
!100
!50
0
50
100
m"$$ #GeV$
m"$!m"$$#GeV
$ Direct searchLHC 980 pb!1!v"#10!6GeV"
Sum Rule
Sum Rule &Z width
LEP EWPTmh#130GeV
!
0 100 200 300 400 500 600 700
!100
!50
0
50
100
m"$$ #GeV$
m"$!m"$$#GeV
$ ! < 3
CMS data
Melfo, MN, Nesti, Senjanović, Zhang ’11
CMS-PAS-HIG-11-007
Light Higgs
cmh = 130 GeV
c
Type II Roadmap
Direct searchLHC 980 pb!1!v"#10!6GeV"
Sum Rule
Sum Rule &Z width
LEP
EWPTmh#300GeV
0 100 200 300 400 500 600 700
!100
!50
0
50
100
m"$$ #GeV$
m"$!m"$$#GeV
$ ! < 3
CMS data
Melfo, MN, Nesti, Senjanović, Zhang ’11
CMS-PAS-HIG-11-007
Heavy Higgs
cmh = 300 GeV
Conclusions
signal may require new physics at TeV
Left-Right symmetry @ LHC a natural example
no tension with cosmology, precision data or LFV
links oscillations, cosmology and the LHC
Exclusions with fairly low luminosity and 7 TeV
LHC may observe LNV and in turn connect it to low
energy rates, both LNV and LFV
0!2"
Thank you.
Higgs decay
Heavy Higgs decay: a way to probe !
500200 3001500.0
0.5
1.0
1.5
Mh !GeV"
!
10"
100"
Br(h ! WW )mh > 2m!
!h!!++!!! ! !2
!h!!+!! ! (! + "/2)2
Higgs Br’s change
Easy to search if
Hidden if
!++
!0
Akeroyd, Moretti ’11
Melfo, MN, Nesti, Senjanović, Zhang ’11
1.64`
23
4
1000 1500 2000 2500 30001
5
10
50
100
500
1000
MWR !GeV"
MN
!!GeV
"
CMS ! ! Missing Energy
! ! Displaced Vertex
! ! jet#EM activity"N#1 mm
"N#5 m
0$2%$HM%
D0:dijets
L&33.2pb'1
A global pictureMN, Nesti, Senjanović, Zhang ’11
Non-minimal case
1200 1300 1400 1500 1600 1700 1800
0.6
0.8
1.0
1.2
1.4
MWR !GeV"
gR#g L
Minimal case: gL = gR C : VLCKM
= VRCKM!
Maiezza, Nesti, MN, Senjanović ’10
mN = 500 GeV
95% CL
And the ?
Less important, loop suppressed
no log enhancement
flavor structure always
WR
Still, future useful
J-PARC and Fermilab
could probe the mediator
even CP phases if LR
µ N ! e N
Cirigliano, Kitano, Okada, Tuzon ’09
Bajc, MN, Senjanović ’09
VL mN/MWRVL
†
mN < MWR
Role of
Flavor structure in muon-electron transitions
!13
A(µ ! e) "!m2
N13
m2!++
!
!m2S
2!m2A
sin 2!12 cos !23 + ei! sin !13 sin !23
"
A(µ ! 3e) "!
#mN1+ expi! mN2
"
sin 2!12 cos !23!
mN1cos2 !12 + expi! mN2
sin2 !12
"
/m2
!++
conversion and depend a lotµ ! e µ ! e!
insensitive to µ ! 3e !13
Role of
Flavor structure in muon-electron transitions
!13
A(µ ! e) "!m2
N13
m2!++
!
!m2S
2!m2A
sin 2!12 cos !23 + ei! sin !13 sin !23
"
A(µ ! 3e) "!
#mN1+ expi! mN2
"
sin 2!12 cos !23!
mN1cos2 !12 + expi! mN2
sin2 !12
"
/m2
!++
conversion and depend a lotµ ! e µ ! e!
insensitive to µ ! 3e !13
0 !2 ! 3 !
22 !
0.200
0.100
0.050
0.020
0.010
0.005
0.002
0.001
"
#mS2
2#mA2!sin2$
12cos$23%ei"sin$ 13sin$ 23" Impact of non&zero $13
T2Ksin22$13'0.11
Minossin22$13'0.04
sin22$13'8x10&4
$13'0