Recent developments in Dark Matter Malcolm Fairbairn

PART 1 :- DAMA/LIBRA signal and interpretation PART 2 :- PAMELA, ATIC signal and interpretation

Part 1 DAMA/LIBRA signal and interpretation

Direct detection of dark matter

Earth goes round Sun, Sun goes round Galaxy

DAMA/Libra experiment 250 kg of NaI(Ti)

Quenching in NaI

Channeled events create more electrons and bigger signal Channelling in NaI

DAMA/LIBRA results

DAMA/LIBRA interpretation

MF, Schwetz-Mangold, DAMA/LIBRA interpretation

However, large tension exists with XENON-10 and CDMS data... DAMA signal therefore cannot be dark matter?

Non Extensive Statistics At any given time, probability of a particular delay time, t, given by Over course of a year,  varies quite a lot due to seasonal factors. Therefore, over the long term, one needs to include fluctuations in 

Non Extensive Statistics if  is sum over Gaussian random variables... leads to a   distribution... which yields

Applied to train times

Non Extensive Statistics of Dark Matter Distributions

Is such a halo conceivable? To see, we need to solve Jeans equation

Part 2 PAMELA, ATIC signal and interpretation

Resurs-DK1 satellite Mass: 6.7 tonnes Height: 7.4 m Solar array area: 36 m 2 Main task: multi-spectral remote sensing of earth’s surface Built by TsSKB Progress in Samara, Russia Lifetime >3 years (assisted) Data transmitted to ground via high-speed radio downlink PAMELA mounted inside a pressurized container

Positrons Secondary production ‘Leaky box model’ R. Protheroe, ApJ 254 (1982) 391. Secondary production ‘Moskalenko + Strong model’ without reacceleration. ApJ 493 (1998) 694. Primary production from  annihilation (m(  ) = 336 GeV) Secondary production ‘M+S model’ + primary  distortion PAMELA Baltz + Edsjö, Phys Rev D59 (1999) STOLEN FROM 2007 PRESENTATION BY MARK PEARCE, KTH STOCKHOLM

Adriani et al Discrepancy may be explained by variable solar activity. This one not!

Is it actually positrons? ( ) Intensity of cosmic ray protons at 10 GeV exceeds that of positrons by 5 x 10 5

ATIC AMS PPB Chang et al. Nature 456, 362, 20 th November 2008

Cholis et al Compatibility of the two experiments

Can be interpreted as Dark matter Cut-off corresponding to 620 GeV KK particle However, need large boost factors, B = ( 10, 10 2, 10 3 ) for m DM = ( 100 GeV, 1 TeV, 10 TeV) respectively

Branching ratio into e + e - Thermally averaged self annihilation cross section at freeze-out Thermally averaged self annihilation cross section today Expected local density (0.3 GeV cm -3 ) Actual local density Possible origins of the Boost Factor

Problems with diffusion equations? Diffusion term = f(r)?, f  f(E)? Energy loss term = f(r)?, f  f(E)? Energy injection term = f(r)?, f  f(E)?

Probes of GUT scale physics Decay of WIMP via dimension six operator. Decay of WIMP via dimension five operator. Avanitaki et al. arXiv:

Probes of GUT scale physics Lower Limit on dark matter lifetime

Probes of GUT scale physics Avanitaki et al. arXiv:

Probes of GUT scale physics What a fit!until Monday...

New H.E.S.S. data

New Fermi Data

Astrophysical origin of electrons/positrons 10 GeV – 10 TeV SNR - Secondary Pulsars - Primary Where are we now?

high energy electron/positron flux > 10 GeV still anomalously large Can fit FERMI by assuming local increase in SNR, but not PAMELA Grasso et al

FERMI and PAMELA can be simultaneously fitted with local pulsars Grasso et al

Where are we now with dark matter interpretations? Spectral shape well fitted by dark matter annihilating into muons required self annihilation cross section ~ 1000 times larger than expected need to avoid annihilations into hadrons (no anomalous antiproton signal) No feature at GeV a la ATIC

If you accept these prerequisites, Fermi, HESS and PAMELA data can be fit by dark matter also...

Branching ratio into e + e - Thermally averaged self annihilation cross section at freeze-out Thermally averaged self annihilation cross section today Expected local density (0.3 GeV cm -3 ) Actual local density Possible origins of the Boost Factor

Sommerfeld Enhancement S-channel annihilations P-channel annihilations Need something else to enhance the cross section. If Then dark matter particles are pulled together by exchange of W,Z bosons, enhancing annihilation by

Sommerfeld Enhancement ATIC data suggested DM particle of GeV, W, Z no good. Instead, consider much lighter GeV boson, weakly coupled (Arkani-Hamed & Weiner ) Also DM annihilates through boson – muon final states! However, since cross section goes like 1/v, forms problems for first structures formed (Kamionkowski and Profumo)

CDF Halloween Particle ? DATA MONTE CARLO

Two component dark matter MF and Zupan First component is the dark matter today. Second component decays into first. AAAAAAAAA

Two component dark matter

Conclusions DAMA/LIBRA data shows annual modulation Interpretation of that as dark matter contradicts with XENON/CDMS Can reconcile the two with non-standard density profiles Both PAMELA and FERMI show new population of electrons Dark matter is possible explanation Requires large boost factor and leptophilic decays Can also be explained by astrophysics Difficult confused future for this discovery channel for ordinary WIMPs PART 1 PART 2