susy-qcd corrections to (co)annihilation and their impact...
TRANSCRIPT
SUSY-QCD corrections to (co)annihilation andtheir impact on the relic density.
Julia Harz, DESY Hamburgin collaboration with B. Herrmann, M. Klasen, K. Kovarik and Q. Le Boulc’h
Theoretisches Seminar, Bonn
3.12.2012
Relic density predictionDM@NLO - an extension for numerical relic density calculators
Phenomenology of neutralino-stop coannihilationAnalytical discussion
Results
Overview
1 Relic density prediction
2 DM@NLO - an extension for numerical relic density calculators
3 Phenomenology of neutralino-stop coannihilation
4 Analytical discussion
5 Results
Julia Harz SUSY-QCD corrections to (co)annihilation 1 / 37
Relic density predictionDM@NLO - an extension for numerical relic density calculators
Phenomenology of neutralino-stop coannihilationAnalytical discussion
Results
Overview
1 Relic density prediction
2 DM@NLO - an extension for numerical relic density calculators
3 Phenomenology of neutralino-stop coannihilation
4 Analytical discussion
5 Results
Julia Harz SUSY-QCD corrections to (co)annihilation 2 / 37
Relic density predictionDM@NLO - an extension for numerical relic density calculators
Phenomenology of neutralino-stop coannihilationAnalytical discussion
Results
Constraining the SUSY parameter spaceNeutralino - LSP and cold dark matter candidate
Interplay between LHC and PLANCKdata will be even more interesting
Particle physics bounds
Collider searchese.g.mχ0
1> 46 GeV , mt > 95.7 GeV
PDG (2012)
Precision measurementse.g.Br(b → sγ) = (3.55±0.26) ·10−4
HFAG collaboration (2010)
Cosmology bounds
7 year data of WMAP⇒ Ωh2 = 0.1123± 0.035
WMAP collaboration (2011)
Julia Harz SUSY-QCD corrections to (co)annihilation 3 / 37
Relic density predictionDM@NLO - an extension for numerical relic density calculators
Phenomenology of neutralino-stop coannihilationAnalytical discussion
Results
Calculating the relic density
Today’s number density can be calculated via Boltzmann equation.
dndt
= −3Hn − 〈σeff v〉(
n2 − n2eq
)σ cross section of annihilation andcoannihilation
〈σeff v〉 =∑
ij
〈σijvij〉neq
i
neq
neqj
neq withneq
i
neq ∝ exp[−(mi −mχ)
T
]
Coannihilation...gets important, when masses of LSP and NLSP almost degenerate
K. Griest, D. Seckel. Phys. Rev. D 43 (1991) 10, 3191-3203
Julia Harz SUSY-QCD corrections to (co)annihilation 4 / 37
Relic density predictionDM@NLO - an extension for numerical relic density calculators
Phenomenology of neutralino-stop coannihilationAnalytical discussion
Results
Calculating the relic density
On the basis of the number density one can calculate the relic density.
ΩCDM h2 =mχn0
ρC∝ 1〈σv〉
Public computational programs (e.g.):
DarkSUSYGondolo, Edsjö, Ullio, Bergström, Bringmann et al. [astro-ph/0406204]
MicrOMEGAsBélanger, Boudjema, Pukhov et al. [hep-ph/1004.1092]
SuperIso RelicArbey, Mahmoudi [hep-ph/0906.0369]
Julia Harz SUSY-QCD corrections to (co)annihilation 5 / 37
Relic density predictionDM@NLO - an extension for numerical relic density calculators
Phenomenology of neutralino-stop coannihilationAnalytical discussion
Results
Theoretical uncertainties in the relic density prediction
In cosmology
Choice of cosmological modelHamann, Hannestad, et.al. (2006) [hep-ph/0611582]
Variation in Hubble expansionrateArbey, Mahmoudi (2008) [hep-ph/0803.0741]
In particle physics
Precision of massesAllanach, Kraml, Porod (2003) [hep-ph/0302102]
Uncertainties of spectrum calculatorsBélanger, Kraml, Pukhov (2005) [hep-ph/0502079]
Precision in the calculation of(co)annihilation cross sectionBaro, Boudjema, Semenov (2007) [hep-ph/0710.1821]
Current status in calculating the relic density:
Calculation in public programs only on effective tree level
Current theoretical uncertainties bigger than future precision of PLANCK
Significant impact of NLO-corrections on the relic density
Julia Harz SUSY-QCD corrections to (co)annihilation 6 / 37
Relic density predictionDM@NLO - an extension for numerical relic density calculators
Phenomenology of neutralino-stop coannihilationAnalytical discussion
Results
Current packages at next-to-leading order
- electroweak corrections
Huge number of processes and NLO-diagrams
Automatized calculation
Interface to micrOMEGAshttp://code.sloops.free.fr
- strong corrections
SUSY-QCD corrections to (co)annihilationprocesses
Efficient infrared treatment (dipole subtractionmethod)
Interface to micrOMEGAs (and DarkSUSY inthe future)
http://dmnlo.hepforge.org
Julia Harz SUSY-QCD corrections to (co)annihilation 7 / 37
Relic density predictionDM@NLO - an extension for numerical relic density calculators
Phenomenology of neutralino-stop coannihilationAnalytical discussion
Results
Overview
1 Relic density prediction
2 DM@NLO - an extension for numerical relic density calculators
3 Phenomenology of neutralino-stop coannihilation
4 Analytical discussion
5 Results
Julia Harz SUSY-QCD corrections to (co)annihilation 8 / 37
Relic density predictionDM@NLO - an extension for numerical relic density calculators
Phenomenology of neutralino-stop coannihilationAnalytical discussion
Results
DM@NLO - relic density including QCD corrections
SPhenocalculation of sparticle masses,mixings & precision observables
W. Porod.
?
Inputsetting parameters for cMSSM,
pMSSM,...
MicrOMEGAsintegration of Boltzmann equation,
etc.G. Bélanger, F. Boudjema, A. Pukhov, A. Semenov.
relevant CalcHEP cross sectionsare replaced by DM@NLO calculat-ed NLO cross sections
?
CalcHEPcalculation of (co)annihilation
processes at tree levelA. Pukhov, A. Belyaev, N. Christensen.
-
Outputneutralino relic density
DM@NLOcalculation of cross sections @
NLO level for relevant processesJ.Harz, B. Herrmann, M. Klasen, K. Kovarik, Q. Le Boulc’h.
-
http://projects.hepforge.org/dmnlo Julia Harz SUSY-QCD corrections to (co)annihilation 9 / 37
Relic density predictionDM@NLO - an extension for numerical relic density calculators
Phenomenology of neutralino-stop coannihilationAnalytical discussion
Results
Impact of SUSY-QCD-corrections to annihilation
Example: Dominant Z-exchange
Enhancement of annihilation crosssection into quarks by 50 % throughQCD-corrections
Reduction of the predicted relicdensity
Significant shift of the WMAPfavoured region
10˜
10˜
q
qH0k
10˜
10˜
q
qZ0
10˜
10˜
q
qqi˜
10˜
10˜
q
qqi˜
tan β = 10, A0 = 0,m0 = 1500,M2 = 600, µ > 0Herrmann, Klasen, Kovarik (2009), arXiv:0907.0030 [hep-ph].
⇒ Effect of corrections to the relic density lager than currentexperimental uncertainties!
B. Herrmann, M. Klasen, K. Kovarik
Julia Harz SUSY-QCD corrections to (co)annihilation 10 / 37
Relic density predictionDM@NLO - an extension for numerical relic density calculators
Phenomenology of neutralino-stop coannihilationAnalytical discussion
Results
Impact of SUSY-QCD-corrections to annihilation
Example: Dominant Z-exchange
Enhancement of annihilation crosssection into quarks by 50 % throughQCD-corrections
Reduction of the predicted relicdensity
Significant shift of the WMAPfavoured region
10˜
10˜
q
qH0k
10˜
10˜
q
qZ0
10˜
10˜
q
qqi˜
10˜
10˜
q
qqi˜
tan β = 10, A0 = 0,m0 = 1500,M2 = 600, µ > 0Herrmann, Klasen, Kovarik (2009), arXiv:0907.0030 [hep-ph].
⇒ Effect of corrections to the relic density lager than currentexperimental uncertainties!
B. Herrmann, M. Klasen, K. Kovarik
Julia Harz SUSY-QCD corrections to (co)annihilation 10 / 37
Relic density predictionDM@NLO - an extension for numerical relic density calculators
Phenomenology of neutralino-stop coannihilationAnalytical discussion
Results
Impact of SUSY-QCD-corrections to annihilation
Extension: annihilation of other gauginos
Especially relevant for wino- orhiggsino-like neutralinos
Realisation e.g. in pMSSM
Generalisation of neutralinoannihilation code
Addition of few new contributionsconcerning charginos
χ0/± χ0/±
χ0/± χ0/± χ0/± χ0/±q q q q
q q q q
Z0 H0i
q q
γ W± H±
χ0/±
χ0/±q q
q χ0/±
χ0/± q
q
χ+
χ− q
AbdusSalam, Allanach and Quevedo, Phys. Rev. D 81 (2012).
B. Herrmann, M. Klasen, K. Kovarik, M. Meinecke (in progress).
Julia Harz SUSY-QCD corrections to (co)annihilation 11 / 37
Relic density predictionDM@NLO - an extension for numerical relic density calculators
Phenomenology of neutralino-stop coannihilationAnalytical discussion
Results
Coannihilation with Squarks
Contribution if squarks and neutralinoalmost degenerate
Dominant in different regions ofparameter space
Extendable to coannihilation ofgauginos with sfermions in general
0
100
200
300
400
500
600
700
800
900
1000
1100
Mas
s/
GeV
h0
A0H0
H±
qR
qL
b1
b2
t1
νL
˜R
˜L
τ1ντ
τ2
g
χ01
χ02 χ±
1
χ03
χ04 χ±
2
t2
J.H., B. Herrmann, M. Klasen, K. Kovarik, Q. Le Boulc’h (in progress)
Julia Harz SUSY-QCD corrections to (co)annihilation 12 / 37
Relic density predictionDM@NLO - an extension for numerical relic density calculators
Phenomenology of neutralino-stop coannihilationAnalytical discussion
Results
Overview
1 Relic density prediction
2 DM@NLO - an extension for numerical relic density calculators
3 Phenomenology of neutralino-stop coannihilation
4 Analytical discussion
5 Results
Julia Harz SUSY-QCD corrections to (co)annihilation 13 / 37
Relic density predictionDM@NLO - an extension for numerical relic density calculators
Phenomenology of neutralino-stop coannihilationAnalytical discussion
Results
Phenomenology of neutralino-stop coannihilationFrom particle physics point of view
light stops interesting regarding collider phenomenology
large stop splitting interesting for Higgs mass around 125 GeV
m2h ≈ M2
Z cos2 2β +3g2m4
t
8π2m2W
[ln(
M2SUSY
m2t
)+
X 2t
M2SUSY
(1− X 2
t
12M2SUSY
)]with Xt ≡ At − µ/ tanβ and MSUSY =
√mt1
mt2
max contribution from stop mixing obtained for |Xt |/MSUSY =√
6(m2
q10
0 m2q2
)= U†q
(M2
Q + m2t + M2
Z c2β(T 3q −Qqs2
w ) mtXt
mtXt M2˜tR
+ m2t + M2
Z c2βQqs2w
)Uq
From cosmology point of view
Neutralino-stop coannihilation can contribute significantly to σeff
Julia Harz SUSY-QCD corrections to (co)annihilation 14 / 37
Relic density predictionDM@NLO - an extension for numerical relic density calculators
Phenomenology of neutralino-stop coannihilationAnalytical discussion
Results
Phenomenology of neutralino-stop coannihilationStudy of phenomenological MSSM with 8 free parameters (pMSSM8)
random scan of 1 200 000 points
parameter range:
200 GeV ≤ M1 ≤ 1000 GeV
500 GeV ≤ Mq1,2 ,M ˜ ≤ 4000 GeV
500 GeV ≤ Mq3 ≤ 2500 GeV
100 GeV ≤ mA ≤ 2000 GeV
2 ≤ tanβ ≤ 50
|µ| ≤ 3000 GeV
|Tt | ≤ 5000 GeV
χn0˜
qi˜
q’
φq
χn0˜
qi¯
q’
φ
qj˜χn0˜
qi¯
q’
φχk0˜
χn0˜
qi˜
q’
Vq
χn0˜
qi¯
q’
V
qj˜χn0˜
qi¯
q’
Vχk0˜
with φ = h0, H0, A0, H± , V = Z0, W± , (γ), (g)
Constraints:
0.0773 ≤Ωχh2 ≤ 0.1473
120 GeV ≤mh0 ≤ 130 GeV
2.5× 104 ≤BR(b → sγ) ≤ 4.6× 104
Julia Harz SUSY-QCD corrections to (co)annihilation 15 / 37
Relic density predictionDM@NLO - an extension for numerical relic density calculators
Phenomenology of neutralino-stop coannihilationAnalytical discussion
Results
Phenomenology of neutralino-stop coannihilationAll points with coannihilation:
h0, H0, A0, H±, Z0, W±, γ, g
Julia Harz SUSY-QCD corrections to (co)annihilation 16 / 37
Relic density predictionDM@NLO - an extension for numerical relic density calculators
Phenomenology of neutralino-stop coannihilationAnalytical discussion
Results
Phenomenology of neutralino-stop coannihilationCut on Higgs mass:
h0, H0, A0, H±, Z0, W±, γ, g
Julia Harz SUSY-QCD corrections to (co)annihilation 16 / 37
Relic density predictionDM@NLO - an extension for numerical relic density calculators
Phenomenology of neutralino-stop coannihilationAnalytical discussion
Results
Phenomenology of neutralino-stop coannihilationCut on Higgs mass and relic density:
h0, H0, A0, H±, Z0, W±, γ, g
Julia Harz SUSY-QCD corrections to (co)annihilation 16 / 37
Relic density predictionDM@NLO - an extension for numerical relic density calculators
Phenomenology of neutralino-stop coannihilationAnalytical discussion
Results
Phenomenology of neutralino-stop coannihilation:Cut on Higgs mass, relic density and b → sγ:
h0, H0, A0, H±, Z0, W±, γ, g
Julia Harz SUSY-QCD corrections to (co)annihilation 16 / 37
Relic density predictionDM@NLO - an extension for numerical relic density calculators
Phenomenology of neutralino-stop coannihilationAnalytical discussion
Results
Phenomenology of neutralino-stop coannihilationFurther study of 3 different scenarios:
M1 Mq1,2Mq3
M ˜ At mA µ tanβI 306.7 2037.7 709.7 1499.3 1806.5 1495.6 2616.1 9.0II 469.7 1261.2 905.3 1963.2 1515.5 1343.1 725.9 18.3III 314.9 2870.5 763.6 2417.7 1877.5 386.0 2301.5 10.3
χ01 t1 → th0 χ0
1 t1 → tH0 χ01 t1 → tZ 0 χ0
1 t1 → bW + sumI 38.6% – 3.4% 5.9% 47.9%II 26.5% – 11.6% 3.7% 41.8%III 14.0% 20.5% 1.2% 2.1% 37.8%
mχ01
mt1mh0 Ωχh2
I 306.9 350.5 124.44 0.124II 466.4 511.8 124.05 0.145III 317.0 371.4 123.43 0.102
Julia Harz SUSY-QCD corrections to (co)annihilation 17 / 37
Relic density predictionDM@NLO - an extension for numerical relic density calculators
Phenomenology of neutralino-stop coannihilationAnalytical discussion
Results
Phenomenology of neutralino-stop coannihilationContribution of different channels for studied scenarios
M1 Mq1,2Mq3
M ˜ At mA µ tan βI 306.7 2037.7 709.7 1499.3 1806.5 1495.6 2616.1 9.0II 469.7 1261.2 905.3 1963.2 1515.5 1343.1 725.9 18.3III 314.9 2870.5 763.6 2417.7 1877.5 386.0 2301.5 10.3
Julia Harz SUSY-QCD corrections to (co)annihilation 18 / 37
Relic density predictionDM@NLO - an extension for numerical relic density calculators
Phenomenology of neutralino-stop coannihilationAnalytical discussion
Results
Phenomenology of neutralino-stop coannihilationContribution of different channels for studied scenarios
M1 Mq1,2Mq3
M ˜ At mA µ tan βI 306.7 2037.7 709.7 1499.3 1806.5 1495.6 2616.1 9.0II 469.7 1261.2 905.3 1963.2 1515.5 1343.1 725.9 18.3III 314.9 2870.5 763.6 2417.7 1877.5 386.0 2301.5 10.3
Julia Harz SUSY-QCD corrections to (co)annihilation 19 / 37
Relic density predictionDM@NLO - an extension for numerical relic density calculators
Phenomenology of neutralino-stop coannihilationAnalytical discussion
Results
Overview
1 Relic density prediction
2 DM@NLO - an extension for numerical relic density calculators
3 Phenomenology of neutralino-stop coannihilation
4 Analytical discussion
5 Results
Julia Harz SUSY-QCD corrections to (co)annihilation 20 / 37
Relic density predictionDM@NLO - an extension for numerical relic density calculators
Phenomenology of neutralino-stop coannihilationAnalytical discussion
Results
Full next-to-leading order calculation for coannihilation
Virtual corrections
q
q
q
g
q
q
qj˜
g
qi˜
qi˜
qi˜
g
qi˜
qj˜
q
g
qi˜ qj˜
qk˜
χn0˜
V, H
qi˜
q
q
qi˜
q
g
χn0˜
V, H
qi˜
q
qj˜
q
qk˜
g
χn0˜
V, H
q
qi˜
qj˜
q
qk˜
g
χn0˜
V, H
q
qi˜
q
qj˜
q
g
χn0˜
V
q
qi˜
qj˜
q
g
χn0/+˜
q
qi˜
q
qi˜
gV, H
q
q
q
q
gV, H
qi˜
qj˜
qi˜
qj˜
gV
qi˜
qi˜
qj˜
g
χn0/+˜
q
qi˜
qj˜
q
gV, H
q
q
qj˜
qk˜
gV, H
qi˜
qj˜
q
q
gV, H
qi˜
qj˜
qk˜
ql˜
Real emission
χn0˜
qi˜
q
V, H
g
qj˜q
χn0˜
qi˜
q
V, H
g
q
q
χn0˜
qi˜
q
g
V, H
q
q
χn0˜
qi˜
V, H
q
g
χm˜
qj˜
χn0˜
qi˜
V, H
q
g
χm˜q
χn0˜
qi˜
q
V, H
g
qj˜
qj˜
χn0˜
qi˜
q
g
V, H
qj˜
qj˜
χn0˜
qi˜
q
g
V, H
qj˜q
χn0˜
qi˜
q
g
V
qj˜
Julia Harz SUSY-QCD corrections to (co)annihilation 21 / 37
Relic density predictionDM@NLO - an extension for numerical relic density calculators
Phenomenology of neutralino-stop coannihilationAnalytical discussion
Results
Virtual corrections and renormalizationMixed DR-OS-scheme
input parameters: mMSb ,mOS
t ,ADRb ,ADR
t ,mOSb1,mOS
b2,mOS
t1
treat mt ,mt1,mt2
,mb1,mb2
in OS-schememb,At ,Ab in DR-scheme
renormalization of squark mixing matrizes before rotation→ counter term for mixing angle δθ appears(
cos θq sin θq− sin θq cos θq
)(m2q1
00 m2
q2
)(cos θq − sin θqsin θq cos θq
)=(
M2Q + m2
q + M2Z c2β(T 3
q − Qqs2w ) mq(Aq − µ∗κ)
mq(Aq − µκ) M2qR
+ m2q + M2
Z c2βQqs2w
)
in interaction eigenstates five soft parameters: M2Q ,M
2tR,M2
bR,At ,Ab
in mass eigenstates six parameters: mt1,mt2
, θt ,mb1,mb2
, θb→ choose mt2
as dependent parameter
Julia Harz SUSY-QCD corrections to (co)annihilation 22 / 37
Relic density predictionDM@NLO - an extension for numerical relic density calculators
Phenomenology of neutralino-stop coannihilationAnalytical discussion
Results
Virtual corrections and renormalization
Mixed DR-OS-scheme
Important issue by calculating counterterm δθ:choose θ such that
δθ =1
m2q1−m2
q2
· 1cos2 θ − sin2 θ
remains stable→ θ 6= 0→ θ 6= π/4
Julia Harz SUSY-QCD corrections to (co)annihilation 23 / 37
Relic density predictionDM@NLO - an extension for numerical relic density calculators
Phenomenology of neutralino-stop coannihilationAnalytical discussion
Results
Virtual corrections and renormalizationContribution of different virtual corrections:
Julia Harz SUSY-QCD corrections to (co)annihilation 24 / 37
Relic density predictionDM@NLO - an extension for numerical relic density calculators
Phenomenology of neutralino-stop coannihilationAnalytical discussion
Results
Real corrections and infrared treatment
Phase-space-slicing
σNLO =
∫2→3
dσR +
∫2→2
dσV
σbrems2→3 (λ) = σsoft (∆E , λ) + σhard (∆E)
M =i(2p − k)µεµ(k)
(p − k)2 −m2
(−igsT a)A0(p − k)
M = −(gsT a) ε.p
p.kM0 with kµ pµ
(dσdΩ
)soft
= −(
dσdΩ
)0× g2
s CF
(2π)3
∫|~k|≤∆E
d3k2ω
−2k1.p2
(p2.k)(k1.k)
Julia Harz SUSY-QCD corrections to (co)annihilation 25 / 37
Relic density predictionDM@NLO - an extension for numerical relic density calculators
Phenomenology of neutralino-stop coannihilationAnalytical discussion
Results
Real corrections and infrared treatment
Phase-space-slicing
σNLO =
∫2→3
dσR +
∫2→2
dσV
σbrems2→3 (λ) = σsoft (∆E , λ) + σhard (∆E)
M =i(2p − k)µεµ(k)
(p − k)2 −m2
(−igsT a)A0(p − k)
M = −(gsT a) ε.p
p.kM0 with kµ pµ
(dσdΩ
)soft
= −(
dσdΩ
)0× g2
s CF
(2π)3
∫|~k|≤∆E
d3k2ω
−2k1.p2
(p2.k)(k1.k)
Julia Harz SUSY-QCD corrections to (co)annihilation 25 / 37
Relic density predictionDM@NLO - an extension for numerical relic density calculators
Phenomenology of neutralino-stop coannihilationAnalytical discussion
Results
Real corrections and infrared treatment
Phase-space-slicing
σNLO =
∫2→3
dσR +
∫2→2
dσV
σbrems2→3 (λ) = σsoft (∆E , λ) + σhard (∆E)
M =i(2p − k)µεµ(k)
(p − k)2 −m2
(−igsT a)A0(p − k)
M = −(gsT a) ε.p
p.kM0 with kµ pµ
(dσdΩ
)soft
= −(
dσdΩ
)0× g2
s CF
(2π)3
∫|~k|≤∆E
d3k2ω
−2k1.p2
(p2.k)(k1.k)
Julia Harz SUSY-QCD corrections to (co)annihilation 25 / 37
Relic density predictionDM@NLO - an extension for numerical relic density calculators
Phenomenology of neutralino-stop coannihilationAnalytical discussion
Results
Real corrections and infrared treatmentTest of cut off independence:
Julia Harz SUSY-QCD corrections to (co)annihilation 26 / 37
Relic density predictionDM@NLO - an extension for numerical relic density calculators
Phenomenology of neutralino-stop coannihilationAnalytical discussion
Results
Real corrections and infrared treatmentContribution of 2→ 3 processes:
Julia Harz SUSY-QCD corrections to (co)annihilation 27 / 37
Relic density predictionDM@NLO - an extension for numerical relic density calculators
Phenomenology of neutralino-stop coannihilationAnalytical discussion
Results
Special treatment: on-shell propagatorsDiagram subtraction scheme
Internal top quark in real gluon emission can become on-shellCareful treatment to prevent double-counting
χ01 t1 −→ W + b g|on−shell top =⇒ (χ0
1 t1 → t g)× (t → W +b)
modelling with Breit-Wigner distribution retains interferences withnon-resonant terms
|Msubtr|2 =m2
topΓ2top
(p2top −m2
top)2 + m2topΓ2
top×∣∣Mres
∣∣2∣∣∣on−shell top
χ10˜
t1˜
b
W
g
t
t
χ10˜
t1˜
b
W
g
t1˜t
Julia Harz SUSY-QCD corrections to (co)annihilation 28 / 37
Relic density predictionDM@NLO - an extension for numerical relic density calculators
Phenomenology of neutralino-stop coannihilationAnalytical discussion
Results
Overview
1 Relic density prediction
2 DM@NLO - an extension for numerical relic density calculators
3 Phenomenology of neutralino-stop coannihilation
4 Analytical discussion
5 Results
Julia Harz SUSY-QCD corrections to (co)annihilation 29 / 37
Relic density predictionDM@NLO - an extension for numerical relic density calculators
Phenomenology of neutralino-stop coannihilationAnalytical discussion
Results
Impact of SUSY-QCD-corrections to cross sectionScenario II
χ01 t1 → th0 χ0
1 t1 → tH0 χ01 t1 → tZ 0 χ0
1 t1 → bW + sumII 26.5% – 11.6% 3.7% 41.8%
Julia Harz SUSY-QCD corrections to (co)annihilation 30 / 37
Relic density predictionDM@NLO - an extension for numerical relic density calculators
Phenomenology of neutralino-stop coannihilationAnalytical discussion
Results
Impact of SUSY-QCD-corrections to cross sectionScenario I & III
χ01 t1 → th0 χ0
1 t1 → tH0 χ01 t1 → tZ 0 χ0
1 t1 → bW + sumI 38.6% – 3.4% 5.9% 47.9%
III 14.0% 20.5% 1.2% 2.1% 37.8%
Julia Harz SUSY-QCD corrections to (co)annihilation 31 / 37
Relic density predictionDM@NLO - an extension for numerical relic density calculators
Phenomenology of neutralino-stop coannihilationAnalytical discussion
Results
Impact on the relic densityReduction of relic density through next-to-leading order calculation
WithΩCDM h2 =
mχn0
ρC∝ 1〈σv〉
relic density gets shift of ≈ 10 %
Julia Harz SUSY-QCD corrections to (co)annihilation 32 / 37
Relic density predictionDM@NLO - an extension for numerical relic density calculators
Phenomenology of neutralino-stop coannihilationAnalytical discussion
Results
Impact on relic densityShift of WMAP favoured region of parameter space
Julia Harz SUSY-QCD corrections to (co)annihilation 33 / 37
Relic density predictionDM@NLO - an extension for numerical relic density calculators
Phenomenology of neutralino-stop coannihilationAnalytical discussion
Results
Impact on the relic densityReduction of relic density through next-to-leading order calculation
Julia Harz SUSY-QCD corrections to (co)annihilation 34 / 37
Relic density predictionDM@NLO - an extension for numerical relic density calculators
Phenomenology of neutralino-stop coannihilationAnalytical discussion
Results
Impact on relic densityShift of WMAP favoured region of parameter space
Julia Harz SUSY-QCD corrections to (co)annihilation 35 / 37
Relic density predictionDM@NLO - an extension for numerical relic density calculators
Phenomenology of neutralino-stop coannihilationAnalytical discussion
Results
Outlook
DM@NLO will correct further processesin the futureExample scenario I:
38.56% χ01 t1 → t h
19.81% χ01 χ
01 → t t
14.09% t1 ¯t1 → h h8.01% χ0
1 t1 → G t5.92% χ0
1 t1 → W + b3.37% χ0
1 t1 → Z t
Ongoing work for gluon final states→ sizeable corrections expected(Freitas)
Ongoing work for other processes(e.g. t1¯t1 → h h)
Freitas (2007), arXiv:0705.4027v2 [hep-ph].
Julia Harz SUSY-QCD corrections to (co)annihilation 36 / 37
Relic density predictionDM@NLO - an extension for numerical relic density calculators
Phenomenology of neutralino-stop coannihilationAnalytical discussion
Results
Conclusion
Public codes do not take into account full NLOcorrections
DM@NLO will contain SUSY-QCD corrections toGaugino annihilation and Neutralino-Squarkcoannihilation
sizeable corrections expected and thus an impacton the relic density prediction
Package DM@NLO allows to link SUSY-QCDcorrections to the public codes
→ Code will be public available!http://dmnlo.hepforge.org
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Julia Harz SUSY-QCD corrections to (co)annihilation 37 / 37
Relic density predictionDM@NLO - an extension for numerical relic density calculators
Phenomenology of neutralino-stop coannihilationAnalytical discussion
Results
Julia Harz SUSY-QCD corrections to (co)annihilation 37 / 37