Constraints on dark matter scenarios with nearly
degenerate mass spectra from the cosmic
antiproton flux
Mathias Garny (DESY)
KEK, POwLHC, 16.-18.02.12
based on arXiv:1112.5155, JCAP 1107 (2011) 028 (arXiv:1105.5367)
with Alejandro Ibarra, Stefan Vogl
Mathias Garny (DESY)
Constraints on dark matter with nearly degenerate mass spectra
Constraints on dark matter scenarios with nearly
degenerate mass spectra from the cosmic antiproton flux
Introduction
Electroweak Internal Bremsstrahlung
SU(2)L singlet (Bino-like) DM
SU(2)L doublet (Higgsino-like) DM
Constraints from PAMELA p̄/p measurement
Mathias Garny (DESY)
Constraints on dark matter with nearly degenerate mass spectra
WIMP Dark Matter
mX (TeV)
Upper limits, Joint Likelihood of 10 dSphs
3 ·10−26
µ + µ− Channel
bb̄ Channel
W + W− Channel
τ + τ− Channel
WIMP cross section [cm3 /s]
10-21
:X
____
:DM
10-22
10-23
10-24
10-25
10-26
Feng 2010
101
102
WIMP mass [GeV]
103
Fermi 1108.3546
Limits: 90%
Contours: 90%, 3Σ
10-39
DAMA
10-40
10-41
-42
10
100
on-
10-43
CRESST-II
Xen
WIMP-nucleon cross section ΣSI @cm2 D
10-38
10-44
n
m. ru
com
r
SST
w-th
CRE
S lo
M
CD
S
KIM
S
CDM
v0 = 220 kms, vesc = 550 kms
101
102
m Χ @GeVD
103
Kopp, Schwetz, Zupan 2011
Mathias Garny (DESY)
Constraints on dark matter with nearly degenerate mass spectra
WIMP Dark Matter
Anomalies in e + /e − and e + + e − reported by PAMELA and Fermi:
Dark Matter? (not in this talk)
Fermi 1110.2591
Severe constraints from γ (e.g. Fermi diffuse γ-ray data, IC)
Cirelli, Panci, Serpico 0912.0663
Mathias Garny (DESY)
Constraints on dark matter with nearly degenerate mass spectra
WIMP Dark Matter
p/p
PAMELA p̄/p ratio measurement is in good agreement with
expectation from secondary production
10-3
10-4
BESS 2000 (Y. Asaoka et al.)
10-5
BESS 1999 (Y. Asaoka et al.)
BESS-polar 2004 (K. Abe et al.)
CAPRICE 1994 (M. Boezio et al.)
CAPRICE 1998 (M. Boezio et al.)
HEAT-pbar 2000 (A. S. Beach et al.)
PAMELA
10-6
10-1
1
10
102
kinetic energy [GeV]
PAMELA 1007.0821
This talk: Impact of p̄/p constraints on WIMP with nearly
degenerate mass spectrum
Mathias Garny (DESY)
Constraints on dark matter with nearly degenerate mass spectra
WIMP with nearly degenerate mass spectrum
Scenarios where the dark matter particle χ couples to the Standard
Model via a scalar particle η (e.g. η ≡ q̃) that is nearly degenerate
in mass are difficult to constrain by collider searches of exotic
charged or colored particles
mDM ∼ 102 − 103 GeV,
mη − mDM . O(10 − 100)GeV
Complementarity of collider searches and indirect detection (direct
detection)
Mathias Garny (DESY)
Constraints on dark matter with nearly degenerate mass spectra
Toy Model
Majorana fermion χ (DM) couples to the SM via charged/colored
scalar η, mη & mDM (e.g. slepton/squark)
Coupling to leptons
cf. Cao, Ma, Shaughnessy 2009
χ ≡ (1, 1, 0) ,
η=
+
η
η0
≡ (1, 2, 1/2)
Lfermion
= f χ̄(Le iσ2 η) + h.c. = f χ̄(νeL η 0 − eL η + ) + h.c.
int
Lscalar
= −λ3 (Φ† Φ)(η † η) − λ4 (Φ† η)(η † Φ)
int
Mathias Garny (DESY)
Constraints on dark matter with nearly degenerate mass spectra
Toy Model
Majorana fermion χ (DM) couples to the SM via charged/colored
scalar η, mη & mDM (e.g. slepton/squark)
Coupling to leptons
cf. Cao, Ma, Shaughnessy 2009
χ ≡ (1, 1, 0) ,
η=
+
η
η0
≡ (1, 2, 1/2)
Lfermion
= f χ̄(Le iσ2 η) + h.c. = f χ̄(νeL η 0 − eL η + ) + h.c.
int
Lscalar
= −λ3 (Φ† Φ)(η † η) − λ4 (Φ† η)(η † Φ)
int
2
2
mη2 0 = m22 + (λ3 + λ4 )vEW
, mη2 ± = m22 + λ3 vEW
Mathias Garny (DESY)
Constraints on dark matter with nearly degenerate mass spectra
Toy Model
Majorana fermion χ (DM) couples to the SM via charged/colored
scalar η, mη & mDM (e.g. slepton/squark)
Coupling to leptons
cf. Cao, Ma, Shaughnessy 2009
χ ≡ (1, 1, 0) ,
η=
+
η
η0
≡ (1, 2, 1/2)
Lfermion
= f χ̄(Le iσ2 η) + h.c. = f χ̄(νeL η 0 − eL η + ) + h.c.
int
Lscalar
= −λ3 (Φ† Φ)(η † η) − λ4 (Φ† η)(η † Φ)
int
2
2
mη2 0 = m22 + (λ3 + λ4 )vEW
, mη2 ± = m22 + λ3 vEW
ΩDM h2 ' 0.11
0.35
f
4 mDM 2
100 GeV
Mathias Garny (DESY)
"
4
1 + mη4 ± /mDM
2 )4
(1 + mη2 ± /mDM
+
4
1 + mη4 0 /mDM
#−1
2 )4
(1 + mη2 0 /mDM
Constraints on dark matter with nearly degenerate mass spectra
Toy Model
Majorana fermion χ (DM) couples to the SM via charged/colored
scalar η, mη & mDM (e.g. slepton/squark)
Coupling to leptons
cf. Cao, Ma, Shaughnessy 2009
χ ≡ (1, 1, 0) ,
η=
+
η
η0
≡ (1, 2, 1/2)
Lfermion
= f χ̄(Le iσ2 η) + h.c. = f χ̄(νeL η 0 − eL η + ) + h.c.
int
Lscalar
= −λ3 (Φ† Φ)(η † η) − λ4 (Φ† η)(η † Φ)
int
2
2
mη2 0 = m22 + (λ3 + λ4 )vEW
, mη2 ± = m22 + λ3 vEW
ΩDM h2 ' 0.11
0.35
f
4 mDM 2
100 GeV
"
4
1 + mη4 ± /mDM
2 )4
(1 + mη2 ± /mDM
+
4
1 + mη4 0 /mDM
#−1
2 )4
(1 + mη2 0 /mDM
Coupling to quarks η = (3, 2, 1/6) or η = (3, 2, 2/3)
Mathias Garny (DESY)
Constraints on dark matter with nearly degenerate mass spectra
Indirect detection
For Majorana dark matter, the annihilation rate in the Milky Way
halo into light fermions is strongly suppressed (e.g. MSSM
Neutralino annihilating via squark/slepton)
σvχχ→f f¯ = a + bv 2
Mathias Garny (DESY)
2
a ∝ mf2 /mDM
,
v /c ∼ 10−3
Constraints on dark matter with nearly degenerate mass spectra
Indirect detection
For Majorana dark matter, the annihilation rate in the Milky Way
halo into light fermions is strongly suppressed (e.g. MSSM
Neutralino annihilating via squark/slepton)
σvχχ→f f¯ = a + bv 2
2
a ∝ mf2 /mDM
,
v /c ∼ 10−3
The helicity suppression is lifted by the associated emission of a
gauge boson, yielding annihilation rates which could be large
enough to allow the indirect detection of the dark matter particles
χχ → f f¯V ,
V = γ, W , Z , g
Bergstrom 89; Flores, Olive, Rudaz 89; Drees, Jungman, Kamionkowski Nojiri 93
The 2 → 3 annihilation rate is particularly enhanced when the dark
matter particle is degenerate with the intermediate scalar particle
Mathias Garny (DESY)
Constraints on dark matter with nearly degenerate mass spectra
Virtual Internal Bremsstrahlung
2 → 2 annihilation
σvχχ→f f¯
=
"
mf
O(v )O
mDM
0
2
#
2
+ O(v ) O
mDM
mη
4
2 → 3 annihilation via FSR from nearly on-shell e ± (soft/collinear)
Z
αem 1 1 − x
FSR
2
σvχχ→f
'
dx
log[4mDM
(1 − x)/mf2 ] × σvχχ→f f¯
f¯γ
π 0
x
Mathias Garny (DESY)
Constraints on dark matter with nearly degenerate mass spectra
Virtual Internal Bremsstrahlung
2 → 2 annihilation
σvχχ→f f¯
=
"
mf
O(v )O
mDM
0
2
#
2
+ O(v ) O
mDM
mη
4
2 → 3 annihilation via FSR from nearly on-shell e ± (soft/collinear)
Z
αem 1 1 − x
FSR
2
σvχχ→f
'
dx
log[4mDM
(1 − x)/mf2 ] × σvχχ→f f¯
f¯γ
π 0
x
2 → 3 annihilation via VIB and FSR from off-shell e ±
"
8
4 #
mDM
mDM
αem
VIB/FSR
0
2
σvχχ→f f¯γ =
O(v )O
+ O(v )O
π
mη
mη
Mathias Garny (DESY)
Bergstrom 89; Flores, Olive, Rudaz 89
Constraints on dark matter with nearly degenerate mass spectra
Electromagnetic Internal Bremsstrahlung χχ → f f¯γ
Characteristic feature in the gamma ray spectrum
1
BM1
0.1
0.01
0.001
BM2
Total
Secondary gammas
Internal Bremsstrahlung
1
x2 dN γ,tot /dx
x2 dN γ,tot /dx
Total
Secondary gammas
Internal Bremsstrahlung
0.1
0.01
0.2
0.4
0.6
0.8
1
0.2
x = Eγ /mχ
10
0.4
0.6
0.8
1
x = Eγ /mχ
1
BM3
Total
Secondary gammas
Internal Bremsstrahlung
x2 dN γ,tot /dx
1
x2 dN γ,tot /dx
PSfrag
0.1
0.01
0.001
BM4
Total
Secondary gammas
Internal Bremsstrahlung
0.1
0.01
0.001
0.2
0.4
0.6
0.8
1
0.2
x = Eγ /mχ
0.4
0.6
0.8
1
x = Eγ /mχ
solid: 2σ exclusion
dashed: 5σ dicovery
thin: S/B = 1%
Bringmann, Calore,
Vertongen, Weniger 11
Bergstrom 89; Bringmann, Bergstrom, Edsjo 07
Mathias Garny (DESY)
Constraints on dark matter with nearly degenerate mass spectra
Electroweak Internal Bremsstrahlung
Characteristic feature in the gamma ray spectrum
Bergstrom 89; Bringmann, Bergstrom, Edsjo 07
Limits on the relevant cross sections from the non-observation of an
excess in the cosmic p̄/p ratio measured by PAMELA
MG, Ibarra, Vogl 11; Ciafaloni, Cirelli, Comelli, De Simone, Riotto, Urbano 11; Bell, Dent, Jacques, Weiler 11
Mathias Garny (DESY)
Constraints on dark matter with nearly degenerate mass spectra
Electroweak Internal Bremsstrahlung
vdσ(χχ → γf f¯)
dEγ dEf
vdσ(χχ → Wf f¯0 )
dEW dEf
=
=
Cγf f¯ αem f 4 (1 − x)[x 2 − 2x(1 − y ) + 2(1 − y )2 ]
4 (1 − 2y − µ )2 (3 − 2x − 2y + µ )2
8π 2 mDM
f
f
CWf f¯0 αem f 4
n
4 (1 − 2y − µ )2 (3 − 2x − 2y + µ )2
8π 2 mDM
f
f0
2
2
2
(1 − x)[x − 2x(1 − y ) + 2(1 − y )
2
2
2
4
+ 2(2 − x − 2y )∆µ] + x0 [x + 2y + 2xy − 4y + 2(2 − x − 2y )∆µ + ∆µ ]/4 − x0 /8
o
2
2
+ ∆µ [(1 − 2x)/2 − (1 − y )(1 − x − y )/(2x0 )]
2
2
2
x = EW /mDM , y = Ef /mDM , x0 = MW /mDM , µf = mη
/mDM
, µf 0 = mη
f0
f
χχ → VfR f¯R
χχ → VfL f¯L
Cγf f¯
CZf f¯
CWf f¯0
Cgqq̄
qf2 Nc
qf2 Nc tan2 (θW )
–
N c CF
Nc
2 sin2 (θW )
N c CF
qf2 Nc
(t3f −qf sin2 (θW ))2
sin2 (θW ) cos2 (θW )
Nc
Mathias Garny (DESY)
2
/mDM
, ∆µ = 2(µf 0 − µf )
MG, Ibarra, Vogl 11
Constraints on dark matter with nearly degenerate mass spectra
Electroweak Internal Bremsstrahlung
Spectrum of primary electroweak gauge bosons (for mη± = mη0 )
dNγ /dlnE
104
dNZ /dlnE
dNW /dlnE
dNi /dlnE
103
102
101
100
0
0.2
0.4
0.6
0.8
1
x = E/mDM
mDM = 300 GeV and mη± = mη0 = 330 GeV
dNW
1
=
d ln E
σv (χχ → eē)
MG, Ibarra, Vogl 11
vdσ(χχ → W ēν) vdσ(χχ → We ν̄)
+
d ln E
d ln E
Mathias Garny (DESY)
Constraints on dark matter with nearly degenerate mass spectra
Electroweak Internal Bremsstrahlung
Ratio of 2 → 2 and 2 → 3 cross sections (for mη± = mη0 )
σv(χχ → γeL ēL )/σv(χχ → eL ēL )
104
σv(χχ → ZeL ēL )/σv(χχ → eL ēL )
σv(χχ → Zν ν̄)/σv(χχ → eL ēL )
103
σv(2 → 3)/σv(2 → 2)
σv(2 → 3)/σv(2 → 2)
104
σv(χχ → W eν)/σv(χχ → eL ēL )
102
101
100
σv(2 → 3)/σv(2 → 2)
103
102
σv(χχ → γeē)/σv(χχ → eē)
101
σv(χχ → Zeē)/σv(χχ → eē)
10−1
10−2
SU (2)L singlet DM coupling to Le
σv(χχ → Zν ν̄)/σv(χχ → eē)
mDM = 300GeV
1
mη± /mDM = 1.1, mη0 = mη±
100
10
σv(χχ → W eν)/σv(χχ → eē)
100
1000
mDM [GeV℄
mη± /mDM
mDM = 300 GeV and mη± = mη0
MG, Ibarra, Vogl 11
The 2 → 3 processes dominate for mη . 5mDM
Production of electroweak gauge bosons if mDM > MW /2, sizeable
for mDM & 100GeV
Mathias Garny (DESY)
Constraints on dark matter with nearly degenerate mass spectra
Electroweak Internal Bremsstrahlung
2
Mass splitting mη2 0 − mη2 ± = λ4 vEW
with λ4 ∼ O(1)
105
dNW /dlnE
mη 0 = mη ±
2
m2η0 − m2η± = vEW
104
2
m2η0 − m2η± = 2vEW
σv(χχ → W eν)/σv(χχ → eē)
dNW /dlnE
104
103
102
101
100
0
0.2
0.4
0.6
0.8
103
102
101
100
1
mη± /mDM = 1.1
σv(χχ → W eν)/σv(χχ → eē)
mη 0 = mη ±
2
m2η0 − m2η± = vEW
2
m2η0 − m2η± = 2vEW
100
1000
mDM [GeV℄
x = E/mDM
Longitudinal W-bosons: no kinematic suppression at the endpoint ⇒
harder spectrum, enhanced cross-section
σv (χχ → Weν)
≈
η
sin2 (θW )

4.32 
η
η
η
m2 0 + m2 ±
η
 1 +
m2 0 + m2 ±
2m2 ±

≈
4 
2m2 ±

1
η
4 "
2

1 + λ4

2
2
2
5 (mη0 − mη± )
 σv (χχ → γeē)
2 m2
8
MW
DM
300 GeV
mDM
!2 #
σv (χχ → γeē)
MG, Ibarra, Vogl 11
Mathias Garny (DESY)
Constraints on dark matter with nearly degenerate mass spectra
Constraints on dark matter scenarios with nearly
degenerate mass spectra from the cosmic antiproton flux
Introduction
Electroweak Internal Bremsstrahlung
SU(2)L singlet (Bino-like) DM
SU(2)L doublet (Higgsino-like) DM
Constraints from PAMELA p̄/p measurement
Mathias Garny (DESY)
Constraints on dark matter with nearly degenerate mass spectra
SU(2)L singlet DM
Branching ratio σv (χχ → X )/σv (χχ → γf f¯) for mηu = mηd and
mW /2 mDM = 300GeV mη
DM χ = (1, 1, 0)
DM coupling to Le
DM coupling to eR
DM coupling to qL
DM coupling to uR
DM coupling to dR
η
(1,2,1/2)
(1,1,1)
(3,2,1/6)
(3,1,2/3)
(3,1,-1/3)
Mathias Garny (DESY)
Wf f¯0
4.32
–
7.79
–
–
Zf f¯
1.82
0.30
3.02
0.30
0.30
gf f¯
–
–
61.4
38.4
154
Constraints on dark matter with nearly degenerate mass spectra
SU(2)L singlet DM
Ratio of 2 → 2 and 2 → 3 cross sections for singlet Majorana DM
annihilating into right-handed up-quarks or left-handed quarks,
respectively, with mass splittings ∆m = 10, 50, 100GeV
Singlet DM coupling to uR
SU (2)L singlet DM coupling to uR
105
mη − mDM = 10GeV
50GeV
104
100GeV
103
102
σv(2 → 3)/σv(2 → 2)
σv(2 → 3)/σv(2 → 2)
105
Singlet DM coupling to QL
102
σv(χχ → γqL q̄L )/σv(χχ → qL q̄L )
101
100
σv(χχ → ZuR ūR )/σv(χχ → uR ūR )
100
1000
mDM [GeV]
Mathias Garny (DESY)
100GeV
103
σv(χχ → γuR ūR )/σv(χχ → uR ūR )
100
50GeV
104
101
σv(χχ → guR ūR )/σv(χχ → uR ūR )
SU (2)L singlet DM coupling to qL
mη − mDM = 10GeV
σv(χχ → gqL q̄L )/σv(χχ → qL q̄L )
σv(χχ → ZqL q̄L )/σv(χχ → qL q̄L )
σv(χχ → W qL q̄L )/σv(χχ → qL q̄L )
100
1000
mDM [GeV]
Constraints on dark matter with nearly degenerate mass spectra
Constraints on dark matter scenarios with nearly
degenerate mass spectra from the cosmic antiproton flux
Introduction
Electroweak Internal Bremsstrahlung
SU(2)L singlet (Bino-like) DM
SU(2)L doublet (Higgsino-like) DM
Constraints from PAMELA p̄/p measurement
Mathias Garny (DESY)
Constraints on dark matter with nearly degenerate mass spectra
SU(2)L doublet DM
Two doublets χ1 ≡ (1, 2, − 12 ), χ2 ≡ (1, 2, 12 ) (anomaly free)
Mass splitting from radiative corrections (mχ± − mχ0 )rad ' 0.34GeV
Mass splitting from Dim-5 operator (we assume Λ . 10TeV)
fermion
δLmass
=
i
1h
∗
†
c
T c
†
c
c1 (χ̄1 iσ2 Φ )(Φ iσ2 χ1 ) + c2 (χ̄2 Φ)(Φ χ2 ) + c3 (χ̄2 Φ)(Φ iσ2 χ1 ) + h.c.
Λ
2
vEW
(c3 + |c1 − c2 |)
2Λ
v2
− mχ = EW |c1 − c2 |
Λ
δm±
=
mχ± − mχ =
δm0
=
mχ0
Annihilation via gauge interaction χχ → WW , ZZ
σvχχ→WW
=
σvχχ→ZZ
=
q
2
mχ2 − MW
g4
2 /m2
1 − MW
χ
2
2
32π (mχ2 + mχ± − MW )2
q
mχ2 − MZ2
g4
1 − MZ2 /mχ2
4
2
2
64πcW (mχ2 + mχ0 − MZ )2
Mathias Garny (DESY)
Constraints on dark matter with nearly degenerate mass spectra
SU(2)L doublet DM
Annihilation into fermions via charged scalar η
1
η ≡ (1, 2, − ) : Lint = f (χ̄1 iσ2 η ∗ )eR − λ3 (Φ† Φ)(η † η) − λ4 (Φ† η)(η † Φ)
2
η ≡ (1, 1, 1) : Lint = f (χ̄1 iσ2 Lce )η − λ3 (Φ† Φ)(η † η)
Mathias Garny (DESY)
Constraints on dark matter with nearly degenerate mass spectra
SU(2)L doublet DM
Annihilation into fermions via charged scalar η
1
η ≡ (1, 2, − ) : Lint = f (χ̄1 iσ2 η ∗ )eR − λ3 (Φ† Φ)(η † η) − λ4 (Φ† η)(η † Φ)
2
η ≡ (1, 1, 1) : Lint = f (χ̄1 iσ2 Lce )η − λ3 (Φ† Φ)(η † η)
χχ → γeē via VIB, FSR
"
8
4 #
αem
m
m
DM
DM
VIB/FSR
σvχχ→f f¯γ =
O(v 0 )O
+ O(v 2 )O
π
mη
mη
χχ → Zeē via VIB, FSR, and ISR
"
4
4 #
αem
m
m
DM
DM
VIB/FSR/ISR
σvχχ→f f¯Z
=
O(v 0 )O
+ O(v 2 )O
π
mη
mη
Mathias Garny (DESY)
Constraints on dark matter with nearly degenerate mass spectra
SU(2)L doublet DM
Cross-sections for 2 → 2 and 2 → 3 annihilation
Typically χχ → WW /ZZ channels dominate
The channels χχ → f f¯V can be important for mη ≈ mDM
mη /mDM = 1.5
Mathias Garny (DESY)
mη /mDM = 1.01
Constraints on dark matter with nearly degenerate mass spectra
Constraints on dark matter scenarios with nearly
degenerate mass spectra from the cosmic antiproton flux
Introduction
Electroweak Internal Bremsstrahlung
SU(2)L singlet (Bino-like) DM
SU(2)L doublet (Higgsino-like) DM
Constraints from PAMELA p̄/p measurement
Mathias Garny (DESY)
Constraints on dark matter with nearly degenerate mass spectra
Constraints from PAMELA p̄/p measurement
Rate of p̄ per unit of kinetic energy and volume
dNp̄f
1 ρ2 (~r ) X
Q(T ,~r ) =
hσv
i
f
2 mχ2
dT
f
Isothermal, NFW, Einasto profile with ρ(r ) = 0.39GeV/cm3
Propagation: two-zone diffusion model compatible with B/C ratio,
three parameter sets corresponding to MIN, MED, MAX p̄ flux
Model
MIN
MED
MAX
∂fp̄
= ∇·(K (T ,~r )∇fp̄ )−∇·(V~c (~r )fp̄ )−2hδ(z)Γann fp̄ +Q(T ,~r )
∂t
δ
0.85
0.70
0.46
K0 (kpc2 /Myr)
0.0016
0.0112
0.0765
secondary p̄ flux from
L (kpc)
1
4
15
Vc (km/s)
13.5
12
5
10−3
PAMELA p̄/p
mDM = 300GeV
S+B
S
p̄/p
0=
10−4
Donato, Maurin, Salati, Barrau,
Boudoul, Taillet 01
solar modulation in force field approximation
φF = 500MV
Mathias Garny (DESY)
10−5
100
101
102
kinetic energy T [GeV]
Constraints on dark matter with nearly degenerate mass spectra
Constraints from PAMELA p̄/p measurement
Maximally allowed cross section (95% C.L.) from PAMELA p̄/p
measurement
σv(χχ → W eν) [cm3 /sec]
10−21
χχ → Weν
σv(χχ → W eν)
10−21
excluded from
PAMELA p̄/p
10−22
10−23
MIN
10−24
MED
10−25
MAX
10−26
102
10−20
σv(χχ → guū) [cm3 /sec]
10−20
Isothermal
σv(χχ → guū)
excluded from
PAMELA p̄/p
10−22
10−23
10−24
MIN
MED
Isothermal
10−25
NFW
Einasto
103
χχ → guū
104
mDM [GeV]
10−26
102
NFW
Einasto
MAX
103
104
mDM [GeV]
MG, Ibarra, Vogl 11
Mathias Garny (DESY)
Constraints on dark matter with nearly degenerate mass spectra
Constraints from PAMELA p̄/p measurement
Constraint on the BF in the milky way by imposing thermal relic density
constraint Ωχ h2 = 0.11 in the mDM − ∆m plane for MED propagation
and NFW profile
Singlet DM coupling to leptons
Singlet DM coupling to quarks
BFmax from p̄/p for singlet DM coupling to QL
BFmax from p̄/p for singlet DM coupling to Le
180
180
4.5
5
140
4
120
100
3
80
60
160
mηu − mDM [GeV]
160
mη± − mDM [GeV]
6
200
6
200
2
40
20
2.5
100
2.75
3
3.25
3.5 3.75
4 4.25
1
1000
mDM [GeV]
3
5
140
4
120
100
3
80
60
2
40
20
1.5
100
1.75
2
2.25
2.5 2.75
1
1000
mDM [GeV]
Solid: mηu = mηd
2
Dashed: mη2 u − mη2 d = vEW
(log scale)
Mathias Garny (DESY)
Constraints on dark matter with nearly degenerate mass spectra
Constraints from PAMELA p̄/p measurement
Constraint on the BF in the milky way for Doublet DM
Doublet DM pure gauge
χχ → WW /ZZ /WWZ /WW γ
107
105
104
104
103
MIN
BF
MED
102
MAX
100
102
102
101
BF=1
Iso
NFW
10−1
10−2
NFW, MED
mη /mDM = 1.01
105
101
χχ → WW /ZZ /WWZ /WW γ
χχ → We ν̄/W ēν/Zeē/Z ν ν̄
106
f=0
106
103
Doublet DM coupling to Le
Einasto
103
mDM [GeV]
Mathias Garny (DESY)
BF=1
100
f=0
f=1
10−1
10−2
102
104
f=2
103
104
mDM [GeV]
Constraints on dark matter with nearly degenerate mass spectra
Constraints from PAMELA p̄/p measurement
Upper limits on the boost factor BF in the Milky Way obtained from the
PAMELA p̄/p data for several MSSM benchmark points at 95%C.L.
Model
BM2
BM3
BMJ 0
BMI 0
mDM
[GeV]
453
234
316
141
BF (p̄/p)
2 → 2/3
< 5900
< 1500
< 330
< 11
BF (p̄/p)
2→3
< 1.3 · 105
< 1.3 · 104
< 3.5 · 104
< 6900
in realistic models the upper bounds on the boost factor are at least
one order of magnitude stronger than the conservative bounds
BM3 has been discussed in as a possible explanation of the
PAMELA positron excess, provided the boost factor in the Milky
way is ∼ 3 × 104 Bergstrom, Bringmann, Edsjo 2008
detection of a gamma-ray signal with a 5σ significance at MAGIC II
or at the projected CTA with 30 hours of observation requires a
boost factor in Draco larger than ∼ 104 or ∼ 103 , respectively
Bringmann, Doro, Fornasa 2008
Mathias Garny (DESY)
Constraints on dark matter with nearly degenerate mass spectra
Constraints on dark matter scenarios with nearly
degenerate mass spectra from the cosmic antiproton flux
Conclusion
For Majorana DM the annihilation channels into two fermions and
one gauge boson can be important χχ → f f¯V
The 2 → 3 channel is enhanced if the charged/colored scalar
mediating the annihilation is nearly degenerate in mass with the DM
⇒ Complementarity of IDM/Collider searches
Constraints from PAMELA p̄/p data on the order of 10−25 cm3 /sec
for χχ → Weν and 10−26 cm3 /sec for χχ → guū
Mathias Garny (DESY)
Constraints on dark matter with nearly degenerate mass spectra
Constraints on dark matter scenarios with nearly
degenerate mass spectra from the cosmic antiproton flux
Conclusion
For Majorana DM the annihilation channels into two fermions and
one gauge boson can be important χχ → f f¯V
The 2 → 3 channel is enhanced if the charged/colored scalar
mediating the annihilation is nearly degenerate in mass with the DM
⇒ Complementarity of IDM/Collider searches
Constraints from PAMELA p̄/p data on the order of 10−25 cm3 /sec
for χχ → Weν and 10−26 cm3 /sec for χχ → guū
thank you!
MG, Alejandro Ibarra, Stefan Vogl
arXiv:1112.5155, JCAP 1107 (2011) 028 (arXiv:1105.5367)
Mathias Garny (DESY)
Constraints on dark matter with nearly degenerate mass spectra
Density profile
Isothermal profile
ρ(r ) =
ρs
,
1 + (r /rs )2
Navarro-Frenk-White (NFW) profile
ρ(r ) = ρs
1
,
r /rs (1 + r /rs )2
Einasto profile
α
r
2
−1
.
ρ(r ) = ρs exp −
α
rs
Scale radius rs = 4.38, 24.42, 28.44 kpc, respectively, α = 0.17 for the
Einasto profile. Besides, the parameter ρs is adjusted in order to yield a
local dark matter density ρ(r ) = 0.39 GeV/cm3 with r = 8.5 kpc
being the distance of the Sun to the Galactic center and is given,
respectively, by ρs = 1.86, 0.25 and 0.044 GeV/cm3 .
Mathias Garny (DESY)
Constraints on dark matter with nearly degenerate mass spectra
Sommerfelfd enhancement for SU(2)L Doublet DM
Amplitude
Aχχ→SM = s0 A0χχ→SM + s00 A0χ0 χ0 →SM + s± A0χ+ χ− →SM
Enhancement in the perturbative limit
αem
m
αem
m
√ DM
p DM
s00 ' √ 2
, s± ' √ 2
.
2s2W MZ + 2mDM δm0
2 2sW MW + 2mDM δm±
Largest effect for χχ → χ+ χ− → γf f¯ due to ‘ISR’
104
SU (2)L doublet DM coupling to Le
105
mη /mDM = 1.5
SU (2)L doublet DM coupling to uL , mDM = 300GeV
103
SE 1GeV
10
102
101
σv(χχ → γeL ēL )/σv(χχ → eL ēL )
σv(χχ → ZeL ēL )/σv(χχ → eL ēL )
σv(χχ → W eν)/σv(χχ → eL ēL )
100
100
1000
mDM [GeV]
Mathias Garny (DESY)
σv(2 → 3)/σv(2 → 2)
σv(2 → 3)/σv(2 → 2)
104
103
102
101
SE
100
σv(χχ → γuL ūL )/σv(χχ → uL ūL )
10−1
σv(χχ → guL ūL )/σv(χχ → uL ūL )
σv(χχ → ZuL ūL )/σv(χχ → uL ūL )
10−2
10−3
s + p-wave
s-wave
σv(χχ → W qL qL )/σv(χχ → uL ūL )
1
10
mη /mDM
Constraints on dark matter with nearly degenerate mass spectra
Collider constraints
(rough estimate)
coloured scalar
mη > 875 GeV for any mDM (ATLAS dijet 95%c.l 1.04fb− 1)
97 GeV ≤ mη ≤ 875 GeV, if pT , ETmiss . 130 GeV
33 − 44 GeV ≤ mη ≤ 97 GeV, if mη − mDM . 10 GeV (L3 )
charged scalar
60 GeV ≤ mη ≤ 94.4 − 97.5 GeV, if
mη − mDM . 10 − 15 GeV (OPAL, L3, ALEPH)
40 GeV ≤ mη ≤ 60 GeV, if mη − mDM . 5 GeV (DELPHI)
Mathias Garny (DESY)
Constraints on dark matter with nearly degenerate mass spectra