130GeV gamma-ray line
and dark matter中山 和則（東京大学）

CTA研究会＠東京大学宇宙線研究所(2012/9/26)

12年9月26日水曜日

Contents• Evidence for 130GeV gamma-ray line
• Models to explain 130GeV gamma• Future prospects

12年9月26日水曜日

130GeV line ?

12年9月26日水曜日

C.Weniger, 1204.2797
Analyzed 43months Fermi data 20-300GeV.
Chose sky regions that optimize DM signal
for several DM halo profiles.
(Background count from 1-20GeV data)
Performed spectral analysis for chosen sky region
dF= S (EdEE )+EEClaimed 4.6σ evidence for 130GeV line(3.2σ after look-elsewhere effect)m
12年9月26日水曜日

129.8GeVv

1.27

1027

cm /s3

1: Coredisothermal
2: NFW

3: Einasto
4: Contr, α=1.15

Ref. [55] for observational arguments in favor of cored DM profiles).
5: Contr,(NFW)
α=1.3
varro-Frenk-White
profile1ρdm (r) ∝3−α ,α(r/rs ) (1 + r/rs )(2.4), 12年9月26日水曜日
α parametrizes the profile’s inner slope, and α = 1 reproduces

Region3

Region4

4. Upper sub-panels: the measured events with statistical errors are plotted in black.
red
best models
fit withtal bars show
the :best-fit
withDM(red ) and without DM (green), the blue dottedes the corresponding
line fit
flux without
component DMalone. In the lower sub-panel we show resid
green : best
btracting the model with line contribution. Note that we rebinned the data to fewer
12年9月26日水曜日the fits in order to produce the plots and calculate the p-value and the redu
erforming

Profumo, Linden, 1204.6047
The excess region overlaps with Fermi bubble
Broken power law component from Fermi bubble
can mimic the 130GeV gamma line
Tempel, Hektor, Raidal, 1205.1045
195week Fermi data : 130GeV excess with 4.5σ
No artificial choice of the signal region
The excess is not correlated with Fermi bubble
Fermi-LAT collaboration, 1205.2739
2 years data with |b| > 10 + 20 20 around GC
No excess in 4.8GeV - 264GeV12年9月26日水曜日

Distribution of relative signal intensity of 130GeV photons

Excess : ~4σ
Deficit : ~2σTrue excess?
Statistical fluctuation?

“photograph” of our Galaxy in gamma-rays with the energy 120 GeV <ta is shown with blue dots. Fermi bubbles are also shown for illustration.
tive signal intensity of 130 GeV photons in the Galaxy. The green circles
that provide the excess with highest statisticalgrey circles
Tempel, significance;Hektor, Raidal,
1205.1045
ed in table 1; green dot mark the assumed centre of the Galaxy.
12年9月26日水曜日

Table 1. Identified signal regions in the Galaxy, number of photons in the two energy intervals andthe statistical significance of excess in those regions. The radii of regions are all 3 (except for Weniger
Reg3).

Tempel, Hektor, Raidal, 1205.1045Region
Weniger Reg3CentralWestEastNorthl (deg)–110177b (deg)–0.70316.5

N (20–300) GeV
3298
818726481
109significance3.64.53.2
2.7
1.6

10-4E2Φ [GeV cm-2s-1sr-1]

E2Φ [GeV cm-2s-1sr-1]

10-4

N (120–140 GeV)
65
272114410-5

10-5
130 GeV peak significance: 3.2σ

130 GeV peak significance: 4.5σ

l=-10, b=0: r=3deg

Central region (l=-1.0, b=-0.7): r=3deg
20100
E [GeV]13020020100

130200E [GeV]

Figure 3. Best fits to high-energy gamma-ray data for the Central (left panel ) and West (right panel )signal regions presented in table 1, together with 95% CL error band as functions of photon energy.
12年9月26日水曜日

Boyarsky,Malyshev, Ruchayskiy, 1205.4700
3.7years Fermi dataSignificant spatial variations in excess and dip
Dark matter interpretation is “dubious”
Su, Finkbeiner, 1206.1616
3.7years Fermi data
6.5σ evidence for existence of line excess
Hektor, Raidal, Tempel, 1207.4466
130GeV gamma from 6 clusters (3.2σ)
Hektor, Raidal, Tempel, 1209.4548
Finkbeiner, Su, Weniger, 1209.4562
Effects of Earth limb photon is insignificant
12年9月26日水曜日

Su, Finkbeiner, 1206.1616

3Fermi 80 < E < 100 GeV
2.5 9045A) 80<E<100GeV45B)100<E<120GeV

1.500

1.0

1.00.5-45-450.0-90
180-90-180 180

0.50.0900-9090Fermi 120 < E < 140 GeV

2.0450-90-180Fermi 140 < E < 160 GeV90C) 120<E<140GeV452.5D) 140<E<160GeV

2.01.51.5001.01.00.5-45-450.0-90180-90-180 1800.50.0900-9090Fermi 160 < E < 180 GeV
2.5 902.00-90-180

Residual map90E) 160<E<180GeVResidual : C-<A,B,D,E>

45

2.5
2.0
1.5

1.5
1.000

1.0

0.5

0.5-45

0.0-45keV cm-2 s-1 sr-1

45keV cm-2 s-1 sr-1

keV cm-2 s-1 sr-1

2.0

1.5

2.5 90keV cm-2 s-1 sr-1

2.5keV cm-2 s-1 sr-1

keV cm-2 s-1 sr-1

2.0Fermi 100 < E < 120 GeV90-0.50.0-90180900-90-180-90180-1.0900-90-180Fig. 3.— All-sky CLEAN 3.7 year maps in 5 energy bins, and a residual map (lower right). The residual map is the 120 − 140 GeV map
12年9月26日水曜日

2Models to explain
130GeV line

12年9月26日水曜日

Aharonian et al.: Klein-Nishina gamma lines in the G

In order t
we produced
gaussian kern
The correspon
Tempel et al. (white circles.
GeV gammalog.
In the “CeAharonian et al.: Klein-Nishina gamma lines
in theTable
1 Galacti
for thof these “hotIn order to exp
tics in each owe produced corres“hot kernelspots”(coisgaussian
residual flux am
The corresponding
background(sTempel
et al. (2012)
clumpedwhiteofcircles.
The dig
be takensoo
GeVcangamma-raylog. VHE gammaInfalse-positive
the “Central”
Tablein1total)
for thecoot
overof these“hot spots”
possible
assoc
tics in each of them
intriguing opt“hot spots” is 16 (frtwo-peakstrucresidualflux
after
reFig. 3. The count maps of the “Central”, “West” and Reg 1 re- as a superposi
background (see e.ggions (see the text) in two energy intervals, 100-120 TeV and with differentof clumped distribu◦
120-140 TeV, smoothed with 3 FWHM gaussian kernel
at takenthese onlypositi
can beaof this hy
VHEtiongamma-rays.
RegionHot spotlbR, deg TS false-positive
detecttheir magneto
Central359.0-0.7
3in total)
over theuni
possiblemisor

Aharonian, Khangulyan, Malyshev, 1207.0458

They analyzed 52month Fermi data in regions
claimed by Tempel et al., Boyarsky et al., Su et al.
and confirmed excess of ~130GeV gamma.

Inverse-Compton by electrons from cold pulsarwind can produce gamma “line” at ~130GeV.
12年9月26日水曜日

The idea
Inverse-Compton process e +BG

e+eE

BG

me(Thomson regime)eE

BG

me(Klein-Nishina)

Energy of upscattered photon :EE2 BG
eE

Ee =fore me for( e : Lorentz factor of incident electron)f (E )IC byf (E )mono-energeticelectron

E BG
12年9月26日水曜日

EeE

16

“Klein-Nishina line”

14αb4 e E BG
12= 1, 7, 50, 100
10me864200Fig. 2. The
functions oFig. 1. Colour: energy spectra of the inverse Compton radiation row line. T130GeV
BGof mono-energetic electrons upscattering
isotropictarget
phoE> 15 eV
spectrum pb > 30 tons forE 4 /E
<15%
different values of the parameter b: 1, 7, 50 and 100.E dN /dΓ ∝The energy of gamma-rays is in units of the electron energy. areeexpress
Grey: the gamma-ray spectrum produced by electrons with rela- ture”. It can
Thermalemissiondistribution;from neutronstarthe(single
tivistic Maxwellian
in this casephoton pulsar)
energies ? comparable
are in units of 4Θ, where Θ is the “temperature” of Maxwellian achieved atorfromcompanionstar(binarysystems)?
distribution.
one. Mean
12年9月26日水曜日

Dark matter
Many models after Weniger(2012) (~40 paper)
1.27

10 27 cm3 /s

Required cross section
is smaller than the value for correct relic abundance.
DM model w/o producing huge continuum gamma?
v

Constraint from continuum gamma is important.
Most models predict sizable Zγ fraction
Double gamma-ray line (114GeV&130GeV) ?
E =m , m
12年9月26日水曜日

2mZ

4m

J.Cline, 1205.2688

W W , bb̄, · · ·cc Æ gg ê WW+2 subdominant
10101010 - 3

Einasto- 28- 27- 26

H Wino DML‡

continuum
MED++MAX

Typical DM :10 - 2

excluded

MIN PAMELA pbarê p

svH cc Æ ggL

W.Buchmuller, M.Garny, 1206.7056

H Higgsino DMLÊdominant

10 - 25

total cross section sv @ cm ê secD

10 - 24

10 - 23

3Severe constraint
from continuum
gamma and anti-p.

ATg-

10 - 310 - 28

MAXcc Æ gg ê WWMED

10 - 2Einasto10 - 27

10 - 26

excluded

10 -1

MIN PAMELA pbarê pesvH cc Æ ggL ê svlin

12年9月26日水曜日

iLrm

Higgsino/Winois not suitable.

10 0FeSimilar conclusion
for decaying DM

Annihilating DM - ULTRACLEAN

H Wino DML‡

H Higgsino DMLÊ10 - 25

total cross section sv @ cm ê secD

10 - 24

10 - 23

3

Figure 4: Combined fit of the monochromatic line at ⇡ 130GeV as well as them /GeV, ↵, , N , ✓ Z /= {130, 2.67, 0.88, 30.3, 0}(unmasked);= {130, 2.62, 0.80, 31.6, 0}(masked),Supersaturation Constraint

Cohen, Lisanti, Slatyer, Wacker, 1207.0800
m /GeV, ↵, , N , ✓ Z /maxmax

Upper bound on continuum
gamma from DM annihilation.

140(7)

WWRob

where masked (unmasked) refers to removing (including) data 130
within 1 degree of the Galactic
Center. The significance of the best fit point relative to the null 120
model (power-law background) is
5.5 for both the masked and unmasked cases, not including look-elsewhere.4 Masking a 1 degree
110radius circle around the Galactic Center has little e↵ect on the best fit dark matter parameters,
100
though it prefers moreshallow
power-lawbackgrounds.
From
this point onwards, we will only
ann=masked data.
90considerRthe
2+ Z
Figure 1 shows2 the spectrumof photon counts in the region80of interest. The solid red line
70 the likelihood function overcorresponds to the best fit model in Eq. (7) obtained by maximizing< ~100cf. R

200 for neutralino DM

125

130

135
140
m c @GeVD

145

150

FIG. 4: The 95% C.L. excluded region for Rob , as defined in Eq. (10), versus minto W + W , Z 0 Z 0 for the supersaturation analyses using the masked data set. Tththcorresponds to the 2 best fit region. For comparison, Rwino' 200 and RHiggsino
Higgsino dark matter are clearly excluded, as discussed in Sec. IV.

3°around GCCounts

102

1

101C
(ar ontinbitrar uumyn γ(orm Waliz W)
ation)
101

12年9月26日水曜日

W +Wspace.

and Z 0 Z 0 . Clearly, the supersaturation constraint robustly rules outB.

Constraint Utilizing Shape Information

In this section, we present a complementary bound on Rob that utilizes ttinuum spectrum. The ratio Nann /(N + N Z ) is constrained by performing
described in Sec. II B. For a given value of Nann /(N + N Z ) and m , we m
2N , and N Z . This analysis is more 10
constraining
than the supersaturation
but depends
on the assumption that the ray background is described by a s
Eg @GeVD
5–200 GeV.

Constraint from CMB
DM annihilation at recombination epoch
Ionize H
effects on CMB anisotropy

Hisano, Kawasaki, Kohri, Moroi, KN, Sekiguchi, 1102.4658
12年9月26日水曜日

Das, Ellwanger, Mitropoulos,1206.2639
NMSSM is natural framework for solving themu-problem in MSSM.
It can explain 125GeV Higgs boson found at LHC.
Neutralino DM in NMSSM annihilates throughsinglet-like CP-odd Higgs can explain 130GeV gamma.
χ01γ

χ +/−ASγ
χ01Figure 1: The dominant diagram for pair annihilation of χ01 into two photons via a mostly

12年9月26日水曜日

W = SHu Hd +22L = mS |S| +S33A SHu Hd +A S + h.c.
33+| Hu Hd + S 2 |2 + | S|2 (|Hu |2 + |Hd |2 )Mass of As is ~ 260GeV to enhance 2gamma.
m2As3 SA(260GeV)2Mixing of As and Hu, Hd are small.
(Otherwise, As decays into SM quarks)(A2 S)

0Lightest Higgs boson is 126GeV.
Correct thermal relic abundance

0.6
tanO(1)

LSP is the bino with sizable mixing with higgsino
12年9月26日水曜日

Sample point
Parameters
λ0.61
κ0.328Aλ267
Aκ
-114.1tan β
1.8µeff
269
M1150
left-h. slepton masses
150
right-h. slepton masses
160
Ae = Aµ = Aτ500
Sparticle masses
mg̃
971!mq̃ "1530
mt̃1204
mt̃21034mb̃11005
mµ̃L
154
Mχ01129.6Mχ02217
Mχ03287
Mχ04309Mχ05376
Mχ±1210Mχ±237012年9月26日水曜日

Higgs masses
MH1 (= MHSM )MH2MH3MA1 (= MAS )bb
RAS
MA2MH ±Components of χ01
2N112N122
N132
N142N15ObservablesΩh2
σ(p)SI [10−8 pb]!σv"(χ01χ01 → γγ) [10−27 cm3 s−1 ]!σv"(χ01χ01 → Zγ) [10−27 cm3 s−1 ]!σv"(χ01 χ01 → W W ) [10−27 cm3 s−1 ]!σv"(χ01χ01 → ZZ) [10−27 cm3 s−1 ]!σv"(χ01 χ01 → bb̄) [10−27 cm3 s−1 ]!σv"(χ01 χ01 → τ τ̄ ) [10−27 cm3 s−1 ]∆aµ [10−10 ]124.3
256519258.9
3 × 10−3515511
0.826
0.026
0.077
0.065
0.009
0.11
1.21
1.1
0.8
3.46
0.26
0.60
0.09
6.5 ± 3.0

Future prospects

12年9月26日水曜日

Bergstrom, Conrad, Farnier, Bertone, Weniger,
1207.6773
Future prospects for confirming 130GeV line
at HESS-II, CTA, GAMMA-400
Large area, large statistics
Better energy resolution

CTA
GAMMA-400
arXiv:1201.2490

Table 1. A comparison of basic parameters of space-based and ground-based instruments

EGRETSPACED-BASEDGROUND-BASEDAGILE Fermi CALET GAMMA H.E.S.S. MAGIC VERITAS CTA-400

Energy range,
0.030.03GeV
3050Angular
0.20.1resolution, deg EȖ ~ 0.5 GeV EȖ ~ 1 GeV(EȖ > 100 GeV)
Energy1550resolution, % EȖ ~ 0.5 GeV EȖ ~ 1 GeV(EȖ > 100 GeV)12年9月26日水曜日

0.13000.1

1010000
0.1

0.1-3000>100>50>100>10~0.01

0.1

0.1

0.1

0.1

102~115201515

6: Same as: Fig.
but for 5 h of Galactic
observationsobservation
with CTA.
Signal FIG.
region2°3,aroundGC,center
5 hourscommunity,
since the presence of gamma
CTA can confirm/excludeastroparticle
gamma
excessray lines has long been considered a smoking-gun signa
ture of new physics, possibly pointing to the annihilation
γγ/γZ discrimination is difficultof dark matter particles. Of course, future Fermi-LAT

resolution of [18], and we also assume the energy dependence of the effective area from [56]. As signal region, weadopt a circular target region of 2◦ around the Galactic
center.
The signal region definition and background description
we adopted for CTA are similar to the ones dis12年9月26日水曜日

data will be very important: If the Fermi-LAT collabo
ration can exclude instrumental effects as the cause of theSignal region : 20° around GC, ~1 year observation

FIG. 3: Estimated flux and velocity weighted cross-section sensitivities obtained for GAMMA-400 as a function of the DM
particle mass. Black solid: Expected upper limits for γγ final states (with Nγ = 2); red dashed: detection of γγ at 5σ; gree
dot-dashed : discrimination between IB and a monochromatic line (Nγ = 1); blue dotted: discrimination between γZ + γγ anγγ (assuming BR(χχ → γγ)=BR(χχ → γZ)=0.5; Nγ = 1.5). The cross indicates the 130 GeV signature from Ref. [12].

GAMMA-400 can confirm/exclude gamma excess
mayinbe[12]; possible
the events observed above few GeV in our rof converterγγ/γZ
material in discrimination
the tracker and design of anticoincidence systems (which will be very demanding duetoa very excentric orbit) are not fixed yet, but it is very
12年9月26日水曜日

gion of interest can be described by a power-law functio" E #−2.5−11dN/dEbckg = 6 · 10× 1GeV
ph GeV−1 cm−2 s−Summary• There are increasing evidence of 130GeV
gamma line from Galactic center.

• Not likely correlated with Fermi bubble.
• It may be explained by dark matterannihilation or some astrophysical processes.

• CTA will be able to confirm/exclude it.
12年9月26日水曜日

Backup slides

12年9月26日水曜日

Eg =3-10 GeV

Eg =3-10 GeV

Eg =3-10 GeV

101010555

b HdegreesLb HdegreesLb HdegreesL

Hooper, Kelso, Queiroz,1209.3105“robust constraint” on DM from GC region
0-5-100-5-5

Subtract DM contribution with increasing cross section-10105l HdegreesL0-5-10-10105l HdegreesL0Eg =10-100 GeV-5-1010555b HdegreesL

100-5-5-10-10-105l HdegreesL0-5(NFW profile)-10105l HdegreesL
0-5-10-5-100-510l HdegreesL0Eg =10-100 GeV

1005Eg =10-100 GeV

10b HdegreesLb HdegreesL0105l HdegreesL0-5-10: Contour maps of the gamma-ray flux from the region surrounding the Galactic Center, after subtracting varyinssion from dark matter distributed according to an NFW profile. As the flux of dark matter annihilation pred (moving from left-to-right), regions of the maps become increasingly oversubtracted (denoted by dashed ccase of an NFW distribution, this occurs most noticeably in the regions approximately 1-2 north and sou
ic Center.
12年9月26日水曜日

Dashed : over subtracted

12年9月26日水曜日

Comparison with other regions

A comparison of the upper limits on the dark matter annihilation cross section derived in this work to those from ot
ayobservations. In particular, we show the constraints derived from the observations of dwarf spheroidal galaxies [1,12年9月26日水曜日

Frandsen et al., 1207.3971
Prediction on DM direct detection
from loop-induced interaction
real scalar DM :Leff = c

2Fµ Fµ, c 2 Fµ F̃ µfermionic DM :Leff = c ¯ Fµ Fµ, c ¯ Fµ F̃, c ¯ 5 Fµ Fµ, c ¯ 5 Fµ F̃, c¯µFµ F̃µµMOMM(Dirac)q12年9月26日水曜日

qq

Leff = c ¯ Fµ F µMajorana fermion DM3 -1

Xsvrel \gg @ cm s D

10-25

001NOEN

10-26

X-27

10-28

10Fermi-LAT

T
1NONEX-29

1010-30-31

1000

101015 203050 70 100 150 200
m c @GeVDs a function of m from XENON100 (red) and CDMS-IId). The same limits apply to C /m for = R (solid) and
12年9月26日水曜日

Cholis, Tavakoli, Ullio, 1207.1468
Upper bound on continuum
gamma from DM annihilation.
Similar conclusion to Cohen et al.
5040μμ30WWbb
ττee

20

10120

Σ
#Σv$3chan.
!#10$26 cm3 s$1 "Σ#Σv$3chan.
!#10$26 cm3 s$1 "Upper bound on the main mode (Einasto, |L|<5°, |b|<5°)

γγ

Zγ
130

140m Χ !GeV"

12年9月26日水曜日

hγ
150

160

50

40

30

20

10120