icecube 79 solar wimp searchmda65/talks/ic79wimp_brussels.pdf · 2010-10-12 · matthias danninger...

IceCube 79 Solar WIMP Search

Matthias Danninger

Matthias Danninger September 20, 2010 Brussels Collaboration Meeting 2

Overview

● IC79-detector in analysis

● Status & Plans IC79 WIMPs

IC86 sens. study vs. IC79

processing L0/L1/L2

higher analysis levels

● IC79 Dark Matter prospects: summer conferences

how to present results

MODELS considered

• arise in extensions of the Standard Model• assumed to be stable: relics from the Big Bang• mass from few GeV to few TeV

candidates:

• MSSM: lightest super-symmetric particle (LSP) neutralino,

χ01 = z1 1 B + z1 2 W3 + z1 3 H0

1+ z1 4 H02

simulation of “softest” and “hardest” case

hard: m(χ01) [35 GeV – 5 TeV] (τ+τ− / W+W-)

soft: m(χ01) [35 GeV – 5 TeV] (b b)

• Universal extra dimensions: Lightest Kaluza-Klein particle (LKP), B( 1 ) or γ ( 1 )

fixed branching ratios: m(γ ( 1 ) [250 GeV–3TeV]

R


IceCube 79-string detectorfiducial detector volume:

→ all inner strings (2-string veto) → 10 top-DOM veto layer

DeepCore detector volume: → standard definition

parameters & observables:→ HLC-pulses (+fits)

→ seededRTCut cleaned SLC+HLC-pulses (+fits)

115 expected days of data 97% uptime 111.5 days 62% of sens. study→ → →VolumeTrigger not running! 50% sensitivity loss for low masses at filter levelseveral improvements expected (already): filters, SLC & comb. Llh-recopreliminary analysis-framework is prepared ready to start→


IC79 WIMPs analysis plansIceCube-80 + DeepCore-6 sensitivity:

● final geometry & high QE PMTs included(string 79 & 80 @ original location)

● high statistics samples of corsika µ-background and atm backgroundν(incl. coincident 2 and 3 background)μ μ

● Current reconstruction-methods (IceCube-59) used

full analysis chain optimized (all simulation) (incl. multivariate cuts)

IC79 WIMPs starting point

http://icecube.wisc.edu/~mda65/talks/Madison0409.pdfOriginal talk:


Low-level steps IC79 analysis →

General Points

HQE-DOM efficiency

more (new signal MC)

IC86 → IC79 retrigger

SMT4 trigger SMT3→

new analysis framework incl. SLC+HLC pulses

SLC+HLC llh-reco shows improvement for low multipl.-tracks


General Points

HQE-DOM efficiency






IC79 - L0/L1SLC cleaning (fixed)

adjust event-TW ( L2) →-------------------------------optimized online filters (DC wimp events get filtered with 99.9% eff.)+ lowUP_2010

SLC+HLC llh-reco improves string-triggered signal filter-eff. & better background rejection



General Points

HQE-DOM efficiency






IC79 - L0/L1SLC cleaning (fixed)

adjust event-TW ( L2) →-------------------------------optimized online filters (DC wimp events get filtered with 99.9% eff.)+ lowUP_2010

SLC+HLC llh-reco improves string-triggered signal filter-eff. & better background rejection

IC79 - L2Work in progresswith muon-wg,low-E & wimp-wg---------------------------------SLC-hitCleaningincl. best possible SLChits

NFE vs. oldFEX-check, effect on llh-reco

Which L2 track reco

Low Level AnalysisVery important



high-level steps IC79 analysis→

L3

L3 processing wimps?L2 good enough?If L3, muon-wg L3?---------------------------

LLHreco zenith angle [86° < < 120°] Θ

excl. single string events nstring > 1

z_travel > -30m


L3




z_travel > -30m

L4

selection of horizontal track-like events------------------------------

_av < 100m Sum all strings (Sum shortest distance track to string/nchan)

z_extern < 400m



L3




z_travel > -30m

L4

selection of horizontal track-like events------------------------------

_av < 100m Sum all strings (Sum shortest distance track to string/nchan)

z_extern < 400m

L5 (multivariate)

group low-E and high-E

~12“high-quality”variables

determine best TMVA routine(s) 1-or-2 dim cut

IC79-data as Bg (train & test) more independent of MC→



more ideas

Some where around L4-L5

sample of selected high quality horizontal events(O~10 events)⁴---------------------------

improve ang. resolution with SLC+HLC hybrid-reco (5-6 min/event)

finest binning photo-rec, etc. (lot's to investigate here)

invert 10°-bin simulation strategy, only load tables needed

not to separate µ

Only test

Only test


final step ....→

Setting limits

Shape analysis seems like the way to go

Prospects for IC79 IC86 →


Prospects:WIMP-Model-independent Result

effective area for final event selection as function of Eν in the

range 20-1000 GeV, for νµ and anti-νµ from the

direction of the Sun.

The result is an average over the austral winter.

Blue curve optimized for low WIMP masses

Black curve optimized for high WIMP masses

IC22: Systematic effects are included at the 1 level, and statistical σuncertainty of the same level are shown with error bars.

Preliminary

Abbasi et al., Physical Review D81 (2010) 057101. (IC22 result)


WIMP-Model-independent Result

The median angular error , Θ shown with the statistical uncertainty at the 1 level.σ

Preliminary

Hybrid (S. Lafebre)


Kaluza-Klein DM (LKP)Abbasi et al., Physical Review D81 (2010) 057101.

<E νμ

> = 53 GeV


Neutralino DM (LSP)Need to be updated+ incl. new limits(CDMS-2010, superK-2009, more?)

+ add IC86 lifetime of 180d


Neutralino DM (LSP)Updated CDMS 2010 limit

New Super-K analysis (2009) 3109.6dSoft & hard limits

Antares 3y sensitivity not so interesting not shown→

MSSM scan:

Outdated SI-limits





MSSM scan:Currently non-excl. models

Outdated SI-limitsPre-limited DM content





MSSM scan:Currently non-excl. Models

Non-excl Models, even after 10 ³ improvement SI-limits⁻








WMAP favored model Carlos MSSM scan








WMAP favored model CMSSM scan (Darren)







CMSSM scan (Darren)(/data/sim/IceCube/2007/generated/LE_deepcore/darkSUSY/cmssm)

WMAP favored model



Even more plans for futureFrom prospects


AND MORE plans for futureFrom prospectsmSUGRA

CMSSMMSSM

Scan models→ fixed branching ratio→ simulate annihilation spectrum→ (check if equilibrium condition is met)

Convolute with effective neutrino area (livetime etc.)

Compare with number of observed events → limit (e.g. IC79)→ excluded yes/no

Possible to decide model by modelAnd plot various interesting MSSM spaces

J. Edsö + P. Scott (phenomenology side)

me (detector side)


Deep Core events

Thank You


Additional Slides


Neutralino DM (LSP)

IceCube-22 & study: Only used data, when Sun is below the horizon

main syst. uncertainty:Photon propagation in the ice & absolute DOM efficiency (~20%)

relate muon flux and WIMPnucleon crosssection:

IC80-onlyIC80+DC6

Additional mass 35GeV


Additional Slides

Preliminary

Preliminary

icecube 79 solar wimp searchmda65/talks/ic79wimp_brussels.pdf · 2010-10-12 · matthias danninger...

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