Constraining supersymmetry with Fermi and Segue 1patscott/talks/PS_Leicester.pdf · Constraining...
Transcript of Constraining supersymmetry with Fermi and Segue 1patscott/talks/PS_Leicester.pdf · Constraining...
Constraining supersymmetry with Fermi andSegue 1
Pat Scotton behalf of the Fermi-LAT Collaboration
Oskar Klein Centre for Cosmoparticle Physics (OKC) &Department of Physics, Stockholm University
With: Jan Conrad, Joakim Edsjö, Lars Bergström, Yashar Akrami(OKC/Stockholm) & Christian Farnier (Montpellier II,
LPTA/CNRS-UM2)
Based on arXiv:0909.3300 (JCAP in press)Slides available from www.fysik.su.se/̃ pat
Pat Scott – Jan 18 – Leicester Constraining supersymmetry with Fermi and Segue 1
The Fermi Large Area Telescope (LAT)
• Overall modular design.
• 4× 4 array of identical towers (each one including a tracker and a calorimeter module).
• Tracker surrounded by Anti-Coincidence Detector (ACD)
Pat Scott – Jan 18 – Leicester Constraining supersymmetry with Fermi and Segue 1
The Fermi Large Area Telescope (LAT)
• Overall modular design.
• 4× 4 array of identical towers (each one including a tracker and a calorimeter module).
• Tracker surrounded by Anti-Coincidence Detector (ACD)
Tracker• Silicon strip
detectors, Wconversion foils; 1.5radiation lengthson-axis.
• 10k sensors, 80 m2
of silicon active area,1M readout channels.
• High-precisiontracking, short deadtime.
Anti-CoincidenceDetector• Segmented (89 tiles) to
minimize self-veto athigh energy.
• 0.9997 averagedetection efficiency.
Calorimeter• 1536 CsI(Tl) crystal; 8.6 radiation
lengths on-axis.
• Hodoscopic, 3D shower profilereconstruction for leakage correction.
Pat Scott – Jan 18 – Leicester Constraining supersymmetry with Fermi and Segue 1
Fermi-LAT Instrument Response Functions (IRFs)
Effective areaPoint-Spread Function (PSF)Energy dispersion
Pat Scott – Jan 18 – Leicester Constraining supersymmetry with Fermi and Segue 1
Fermi-LAT Instrument Response Functions (IRFs)
Effective areaPoint-Spread Function (PSF)Energy dispersion
Pat Scott – Jan 18 – Leicester Constraining supersymmetry with Fermi and Segue 1
Fermi-LAT Instrument Response Functions (IRFs)
Effective areaPoint-Spread Function (PSF)Energy dispersion
Pat Scott – Jan 18 – Leicester Constraining supersymmetry with Fermi and Segue 1
Fermi-LAT Instrument Response Functions (IRFs)
Effective areaPoint-Spread Function (PSF)Energy dispersion
Pat Scott – Jan 18 – Leicester Constraining supersymmetry with Fermi and Segue 1
Fermi-LAT Instrument Response Functions (IRFs)
Effective areaPoint-Spread Function (PSF)Energy dispersion
Pat Scott – Jan 18 – Leicester Constraining supersymmetry with Fermi and Segue 1
FLATLIB - fast convolution library for processor-intensivemodel scansSource freely downloadable fromwww.fysik.su.se/̃ pat/flatlib
Gamma-rays from neutralino dark matter2 photons (or Z+photon):
monochromatic lines
χ 0
1
χ 0
1
γ
γ/Z
Internal bremsstrahlung:
hard gamma-ray spectrum
Secondary decay:
soft(er) continuum spectrum
χ 0
1
χ 0
1
γ
χ 0
1
χ 0
1
SM
SM
SM
SM
SM
SM
SM
SM
π
γ
γ
γ
Neutralinos: linear combinations ofsuperpartners of γ, Z and H0
Specific example of WIMP darkmatter
Neutral, carries SU(2)L charge,stable if R-parity conserved
3 main gamma-ray channels:monchromatic linesinternal bremsstrahlungcontinuum from secondary decay
Φ ∝ annihilation rate ∝ ρ2DM
Pat Scott – Jan 18 – Leicester Constraining supersymmetry with Fermi and Segue 1
Likely targets
Galactic centreGalactic haloclusters & extragalactic diffusedark clumpsdwarf galaxies
Pat Scott – Jan 18 – Leicester Constraining supersymmetry with Fermi and Segue 1
Likely targets
Galactic centreGalactic haloclusters & extragalactic diffusedark clumpsdwarf galaxies
Pat Scott – Jan 18 – Leicester Constraining supersymmetry with Fermi and Segue 1
7 × 7◦ around the GC
V. Vitale, 2009 Fermi Symposium Poster
Likely targets
Galactic centreGalactic haloclusters & extragalactic diffuse (coming soon)dark clumpsdwarf galaxies
Pat Scott – Jan 18 – Leicester Constraining supersymmetry with Fermi and Segue 1
7 × 7◦ around the GC
V. Vitale, 2009 Fermi Symposium Poster
Likely targets
Galactic centreGalactic haloclusters & extragalactic diffuse (coming soon)dark clumpsdwarf galaxies
Pat Scott – Jan 18 – Leicester Constraining supersymmetry with Fermi and Segue 1
7 × 7◦ around the GC
V. Vitale, 2009 Fermi Symposium Poster
Dark clumps: Ultracompact minihalos
Small-scale, large amplitudedensity perturbations in the earlyUniverse can create ultracompactminihalos (Ricotti & Gould, arXiv:0908.0735)
Known phase transitions couldhave generated the enhancedperturbationsClump mass is set by horizonscale at time of transition =⇒specific clump mass scaleAlso excellent indirect detectiontargets
(PS & Sivertsson, Phys. Rev. Lett. 2009)
Pat Scott – Jan 18 – Leicester Constraining supersymmetry with Fermi and Segue 1
➤
Inte
grat
edflu
xab
ove
thre
shol
d(c
m−
2s−
1)
Energy threshold (GeV)
e +e −
annihilation epoch
QCDphase transition
electroweak phase transition
Scott & Sivertsson 2009
bb̄: no boostµ+µ−: boost = 100
CTA/AGIS
VERITAS+ MAGIC
+ HESS
Fermi -LAT
0.1 1 10 100 103 104
10−
20
10−
15
10−
10
10−
5
bb̄, mχ = 100 GeV
bb̄, mχ = 5 TeV
µ+µ−, mχ = 100 GeV
µ+µ−, mχ = 5 TeV
Dwarf galaxies - constraints on ‘normal’ models
Why dwarfs?Very high mass-to-lightratios=⇒ lots of DM, little BGHigh latitude =⇒ low BG=⇒ arguably the besttargets for WIMP gammas
Pat Scott – Jan 18 – Leicester Constraining supersymmetry with Fermi and Segue 1
C. Farnier, 2009 Fermi SymposiumLAT Collaboration, ApJ submitted
Dwarf galaxies - constraints on boosted models
Pat Scott – Jan 18 – Leicester Constraining supersymmetry with Fermi and Segue 1
C. Farnier, 2009 Fermi SymposiumLAT Collaboration, ApJ submitted
Segue 1 dwarf galaxy
Why Segue 1?Close(ish) – 23 kpcM/L ∼ 1300 (large)The best S/N dwarf forWIMP gammasLeading the pack in Fermidwarf upper limit analysis
Purposes:see if Segue observations do/willimpact real models at all,considering ‘soft bounds’
attempt to validate dwarf ULanalysis via an independent,rather different analysis
Pat Scott – Jan 18 – Leicester Constraining supersymmetry with Fermi and Segue 1
Segue 1100 MeV–300 GeV
Scanning supersymmetric parameter spaces
Goal: given a particular version of SUSY, determine whichparameter combinations fit all experiments, and how well
Issue 1: Combining fits to different experimentsEasy – composite likelihood (L1 × L2 ≡ χ2
1 + χ22)
dark matter relic density from WMAPprecision electroweak tests at LEPLEP limits on sparticle massesB-factory data (rare decays, b → sγ)muon anomalous magnetic moment
Issue 2: Finding the points with the best likelihoodsTough – grid scans, MCMCs, nested sampling or geneticalgorithms (see e.g. arXiv:0910.3950 for genetic)
Model: We focus on the Constrained MSSM (CMSSM)GUT boundary conditions on soft SUSY breaking parameters such thatonly 4 free parameters and 1 sign remainincorporates the simplest implementation of mSUGRA
Pat Scott – Jan 18 – Leicester Constraining supersymmetry with Fermi and Segue 1
Scanning supersymmetric parameter spaces
Goal: given a particular version of SUSY, determine whichparameter combinations fit all experiments, and how well
Issue 1: Combining fits to different experimentsEasy – composite likelihood (L1 × L2 ≡ χ2
1 + χ22)
dark matter relic density from WMAPprecision electroweak tests at LEPLEP limits on sparticle massesB-factory data (rare decays, b → sγ)muon anomalous magnetic moment
Issue 2: Finding the points with the best likelihoodsTough – grid scans, MCMCs, nested sampling or geneticalgorithms (see e.g. arXiv:0910.3950 for genetic)
Model: We focus on the Constrained MSSM (CMSSM)GUT boundary conditions on soft SUSY breaking parameters such thatonly 4 free parameters and 1 sign remainincorporates the simplest implementation of mSUGRA
Pat Scott – Jan 18 – Leicester Constraining supersymmetry with Fermi and Segue 1
m0 scalar mass parameterm 1
2gaugino mass parameter
tan β ratio of Higgs VEVsA0 trilinear couplingsgn µ Higgs mass parameter
(+ve in our scans)
Including Segue 1 in SUSY scans
Same cuts as dwarf UL analysis“DIFFUSE” event class
105◦ zenith angle cut
10◦ ROI
14 energy bins from 100 MeV–300 GeV
Binned Poissonian likelihood (similar to dwarf UL analysis)
Spatial-spectral fit to inner 6× 6 bins of 64× 64 ROI (dwarf ULanalysis assumes point source)
Segue 1 halo profile from best fit Einasto profile by Martinez etal. (2009; JCAP 6:14) (NFW in dwarf UL analysis)
Pat Scott – Jan 18 – Leicester Constraining supersymmetry with Fermi and Segue 1
Including Segue 1 in SUSY scans
Galactic diffuse BG from preliminary Fermi all-skyGALPROP fitsIsotropic powerlaw extragalactic BG (as seen by EGRET)BG normalisations from dwarf UL fits (i.e. full 10◦ × 10◦)Fast integration over energy-dependent IRFs (P6v3) withFLATLIB – (dwarf UL analysis skips energy dispersion)Inclusion of systematic errors from effective area andtheoretical calculations – (dwarf UL analysis skipssystematics)Integration into SUPERBAYES, upgraded with DARKSUSY5 (including internal bremsstrahlung), bug fixes, etc.515 data points in new global fit, vs 11 previously withSUPERBAYES 1.35 (admittedly not such a fair comparison)
Pat Scott – Jan 18 – Leicester Constraining supersymmetry with Fermi and Segue 1
Results - Segue 1 only
mχ1
0 (TeV)
log 10
[ <
σ v>
(cm
3 s−
1 ) ]
Profile likelihood
Flat priors
CMSSM, µ>0
Phys + Nuis only
Scott et al. 2009
0.5 1 1.5
−26
−25
−24
mχ1
0 (TeV)
log 10
[ <
σ v>
(cm
3 s−
1 ) ]
Profile likelihood
Flat priors
CMSSM, µ>0
Segue 9 mth, BF=1
Scott et al. 2009
0.5 1 1.5
−26
−25
−24
mχ1
0 (TeV)
log 10
[ <
σ v>
(cm
3 s−
1 ) ]
Profile likelihood
Flat priors
CMSSM, µ>0
Segue 9 mth, BF=50
Scott et al. 2009
0.5 1 1.5
−26
−25
−24
mχ1
0 (TeV)
log 10
[ <
σ v>
(cm
3 s−
1 ) ]
Profile likelihood
Flat priors
CMSSM, µ>0
Segue 5 yr, BF=1
Scott et al. 2009
0.5 1 1.5
−26
−25
−24
mχ1
0 (TeV)
log 10
[ <
σ v>
(cm
3 s−
1 ) ]
Profile likelihood
Flat priors
CMSSM, µ>0
Segue 5 yr, BF=50
Scott et al. 2009
0.5 1 1.5
−26
−25
−24
Pat Scott – Jan 18 – Leicester Constraining supersymmetry with Fermi and Segue 1
Results - all observables + Segue 1
mχ1
0 (TeV)
log 10
[ <
σ v>
(cm
3 s−
1 ) ]
Profile likelihood
Flat priors
CMSSM, µ>0
All other constr.
Scott et al. 2009
0 0.5 1−30
−28
−26
−24
mχ1
0 (TeV)
log 10
[ <
σ v>
(cm
3 s−
1 ) ]
Posterior pdf
Flat priors
CMSSM, µ>0
All other constr.
Scott et al. 2009
0 0.5 1−30
−28
−26
−24
Relative P
robability Density
0
1
mχ1
0 (TeV)
log 10
[ <
σ v>
(cm
3 s−
1 ) ]
Profile likelihood
Flat priors
CMSSM, µ>0
Segue 9 mth + All, BF=50
Scott et al. 2009
0 0.5 1−30
−28
−26
−24
mχ1
0 (TeV)
log 10
[ <
σ v>
(cm
3 s−
1 ) ]
Posterior pdf
Flat priors
CMSSM, µ>0
Segue 9 mth + All, BF=50
Scott et al. 2009
0 0.5 1−30
−28
−26
−24
Relative P
robability Density
0
1
mχ1
0 (TeV)
log 10
[ <
σ v>
(cm
3 s−
1 ) ]
Profile likelihood
Flat priors
CMSSM, µ>0
Segue 5 yr + All, BF=50
Scott et al. 2009
0 0.5 1−30
−28
−26
−24
mχ1
0 (TeV)
log 10
[ <
σ v>
(cm
3 s−
1 ) ]
Posterior pdf
Flat priors
CMSSM, µ>0
Segue 5 yr + All, BF=50
Scott et al. 2009
0 0.5 1−30
−28
−26
−24
Relative P
robability Density
0
1
Pat Scott – Jan 18 – Leicester Constraining supersymmetry with Fermi and Segue 1
Using extreme (∼95% C.L. excluded) DM profile
mχ1
0 (TeV)
log 10
[ <
σ v>
(cm
3 s−
1 ) ]
Profile likelihood
Flat priors
CMSSM, µ>0
9 mth + All, BF=50, max halo
Scott et al. 2009
0 0.5 1−30
−28
−26
−24
mχ1
0 (TeV)
log 10
[ <
σ v>
(cm
3 s−
1 ) ]
Posterior pdf
Flat priors
CMSSM, µ>0
9 mth + All, BF=50, max halo
Scott et al. 2009
0 0.5 1−30
−28
−26
−24
Relative P
robability Density
0
1
mχ1
0 (TeV)
log 10
[ <
σ v>
(cm
3 s−
1 ) ]
Profile likelihood
Flat priors
CMSSM, µ>0
5 yr + All, BF=50, max halo
Scott et al. 2009
0 0.5 1−30
−28
−26
−24
mχ1
0 (TeV)
log 10
[ <
σ v>
(cm
3 s−
1 ) ]
Posterior pdf
Flat priors
CMSSM, µ>0
5 yr + All, BF=50, max halo
Scott et al. 2009
0 0.5 1−30
−28
−26
−24
Relative P
robability Density
0
1
Pat Scott – Jan 18 – Leicester Constraining supersymmetry with Fermi and Segue 1
Conclusions
Existing 9 month dataset does constrain the CMSSM byitself, but only weakly5 years of data will provide significantly better constraints,but...Not quite good enough to impact models which are notalready disfavoured by other constraints (eg relic density)In the (unlikely) event of a later signal from Segue 1, wecan zero in on the preferred CMSSM model andcross-section very quickly, and provide confidence intervalsConsistent with limits found in the dwarf upper limitanalysisFLATLIB source freely available fromwww.fysik.su.se/̃ pat/flatlib
Pat Scott – Jan 18 – Leicester Constraining supersymmetry with Fermi and Segue 1