Phenomenology ofWino Dark Matter

Shigeki Matsumoto (Kavli IPMU)

1. Why Wino? What is the physics behind it?

2. Direct & indirect detections of the wino.

3. Wino dark matter detections at the LHC.

4. Summary.

CMB, Circular velocity, Galactic clusters, LSS, Bullet clusters, etc.

Why Wino?～ From viewpoint of cosmology ～

Direct detection of DM, Indirect detections of DM (g, p, e±, n, …)

-＋

・ Electrically (color) neutral ・ Non-baryonic (not p or n)・ Stable (or enough stable) ・ Its motion is non-relativistic・ Its interactions are weak. ・ WDMh2 = 0.110 (10-6 GeV/c.c.)Among those conditions, the most remarkable one is the stability of the dark matter. Why the dark matter is stable? Answer will be that there is a symmetry which guarantees the DM stability.

2/17

Why Wino?

When DM has a non-zero B-L DM is “ADM”! mDM = 5 GeV/(B-L)DM. [M. Ibe, S.M., T. Yanagida, PLB708, 2012]

We are focusing on the DM of B-L charge 0 Fermionic dark matter!

SM contains fermions (of B–L charge 1) & bosons (of B–L charge 0)

SM fermion

SM bosonDM

SM fermion

SM fermionDM

(DM is fermion w/ even B–L charge)

(DM is boson w/ odd B–L charge)

Which symmetry stabilizes the dark matter? U(1)B-L gauge symmetry.

(Gauged U(1)B–L ∃(3 x R-neutrinos) Tiny neutrino masses & Leptogenesis)

U(1)B-L is expected to be broken at higher scale by a VEV with (B-L) = 2, a

so that a residual discrete symmetry, Z2 = (-1)B – L ⊂ U(1) B-L, remains.

3/17

Why Wino?

SUSY naturally provides a fermionic dark matter of B-L charge 0.

Recent LHC results are saying

・ SM-like higgs of 125 GeV. ・ No SUSY signals observed. MSUSY ～ 10 TeV when tanb ≫

1

MSUSY ～ 100 TeV when tanb ～ 1

・ Fine tuning of 10-3 – 10-5

is required for mh=125 GeV.

・ No SUSY-Flavor/CP problem.

・ Consistent with negative results of the LHC exp.

～ From viewpoint of particle physics ～

・ Larger MSUSY than expected.

・ L-R mixing of stops is large.

・ Existence of extra-matters

[G. Degrassi, et.al., arXiv:1205.649]

How large should MSUSY be?

4/17

Why Wino? What kind of SUSY model is there behind the high MSUSY

scenario?

Pure Gravity Mediation Model [M. Ibe, S.M., T. Yanagida, PRD85, 2012]

MSSM Sector

SUSY Sector R SectorNo singlets

Scalar fields in MSSM obtain softSUSY mass terms by tree-levelinteractions in supergravity;

m0 ～ m3/2 ～ O(100) TeV

SUSY scalar tri-linear couplings are expected to be suppressed in supergravity at tree level;

A0 ～ 0 ≪ m3/2

Supersymmetric and SUSY higgsmass parameters are generatedthrough tree-level interactionsin supergravity without havinga singlet SUSY breaking field;

m ～ B ～ m3/2 ～ O(100) TeV

[K. Inoue, M. Kawasaki, M. Yamaguchi, T, Yanagida, PRD45, 1992; M. Ibe, T. Moroi, T. Yanagida, PLB 644, 2007] ・ tanb = O(1)・ No gravitino problem [M. Kawasaki, K. Kohri, T. Moroi, PRD71, 2005; M. Kawasaki, K. Kohri, T. Moroi, A. Yotsuyanagi, PRD78, 2008] ・ No Polonyi problem [G. D. Coughlan, W. Fischler, E. W. Kolb, S. Raby, G. G. Ross, PLB131, 1983]

5/17

Why Wino? What kind of SUSY model is there behind the high MSUSY

scenario?

Pure Gravity Mediation Model [M. Ibe, S.M., T. Yanagida, PRD85, 2012]Gaugino masses are dominated byone-loop contributions in super-gravity, i.e. the anomaly mediatedcontributions. The gaugino massesare therefore suppressed by loopfactor in comparison with m0.Furthermore, higgsino thresholdcontributions is of the order ofa loop factor times m3/2, which gives sizable effects on massesof gauginos (Bino and Winos).

[G. F. Giudice, M. A. Luty, H. Murayama, R. Rattazzi, JHEP9812, 1998. L. Randall, R. Sundrum,NPB557, 1999; M. Dine, D. MacIntire, PRD46, 1992; T. Gherghetta, G. F. Giudice, J. D. Wells, NPB559, 1999; M. Ibe, T. Moroi, T. Yanagida, PLB644, 2007]

・ Neutral Wino is the dark matter

・ Only gauginos are directly accessible in the near future.

6/17

1. Thermal production m < 2.7 　 TeV

2. Non-thermal production (Wh2)NT = 0.16(m/300 GeV)(TR/1010 GeV) For successful leptogenesis, TR > 109.5 GeV m < 1 TeV

How heavy the wino can be?

Hisano, S.M., Nagai, Saito, Senami, PLB646 (2007).

Why Wino?

7/17

Direct & indirect detections of Wino dark matter

(Ge, Xe, etc.)

Using underground instruments,dark matter will be detected by observing recoil energies caused by scattering with nucleus.

Scattering cross section betweenWino dark matter and a nucleonis estimated to be ～ 10-47 cm2 when the higgs mass is 125 GeV.

[J. Hisano, K. Ishiwata, N. Nagata, PLB690, 2010]

DM

Nucleus

Direct detection of the Wino dark matter

Scattering cross section should be smaller than 3 x 10-45 cm2 for mDM =100 GeV and 2 x 10-44 cm2 for mDM = 1 TeV because of the latest result of the XENON100.

Scattering cross section of the wino is two orders of magnitude smatter than the above limit.

8/17

We are here!

Extra Galactic g(Clusters, dSphs)

p, p, e± -

g

Dark matter will (may) be detected by observing the products (gamma, anti-p, etc.) coming from dark matter annihilations in our galaxy (or nearby galaxies).

Wino dark matter annihilates first into W boson pairs, and the annihilation products are provided through complicated cascade decays of the W bosons.130 GeV line gamma-ray as well as the PAMEL anomaly cannot be reproduced by the Wino dark matter with being consistent with other indirect detections.

DM halo

g

0.01

0.1

1

10

0.1 0.5 1 1.5Wino mass (TeV)

Annihilation cross section (in unit of 10–24 cm3 /s)

Wino + Wino W+ W–

Tree

Sommerfeld enhanced

[Hisano, S.M., Nojiri, PRL92, 2004]

Direct & indirect detections of Wino dark matter9/17

[A.Abdo et al. (LAT), APJ, Suppl.188, 2010]

～ Indirect detection using gamma ray ～

　　　 Where it comes from?　

・ Galactic center ・ Galactic clusters ・ Galactic cluster ・ Diffused gamma・ Milky-way satellites (dSphs)

At present, observation of dSphs gives the most severe limit on sv.

There are some ambiguities in the calculation of the g ray flux, which is caused by DM profiles in dSphs. (Especially, for ultra faint ones)

Fermi-LAT HESS

Observation

Since g-ray signal from DM annihilation has not been observed yet, we have a limit on its cross section (sv). For Wino DM, sv is directly related to its mass. mWino > 300 ～ 500 GeV

Direct & indirect detections of Wino dark matter 10/17

～ Indirect detection using anti-protons ～

PAMELA AMS-02

Observation

Since anti-protons change their directions during the propagation in our galaxy, signal is observed as an anomalous excess of cosmic ray

There are some ambiguities in the calculation of anti-proton fluxes, which is caused by DM profile in the galactic center as well as the propagation model. The latter one will be refined by the on-going experiment, say AMS-02.

Since anti-p signal from annihilationof DM has not been observed yet, we have a limit on its cross section (sv). PAMELA: mWino > 210-700 GeV

AMS-02: mWino > O(1000) GeV

Direct & indirect detections of Wino dark matter 11/17

Signal is observed as an anomalousexcess of the e-component of CR.Since electron/positron loses itsenergy during the propagation viainverse Compton scatterings. Allthe energetic electrons/positronsoriginate in some sources close tothe solar system. Uncertainties ofthe propagation is small comparedto that of the anti-p observation.On the other hand, some BG exists which mimics the signal.

　　　　　　 PEMALE-Anomaly ！　

　　　 Dark matter or astro-activity ？

Dark matter: Some models exist

Astro-activity: Rotating Pulsars

PAMELA AMS-02

Direct & indirect detections of Wino dark matter～ Indirect detection using electron/positron

～ Observation

12/17

～ Indirect detection using CMB anisotropy ～

WMAP PLANCK

Observation

The dark matter annihilation at recombination epoch may affect the spectrum of CMB anisotropy.

The cross section of the dark matter annihilation is larger, the energy injection to cosmic environment is larger, resulting in the modification of spectrum.

Cosmological and astrophysical uncertainties are quite small.

Since the observed CMB spectrum is reproduced without DM effects, we have a limit on its cross section (sv). WMAP: mWino > 230 GeV

PLANCK: mWino > 500 GeV

[Ibe, S.M., Yanagida, 2012]

Direct & indirect detections of Wino dark matter 13/17

Wino dark matter detections at LHC～ Conventional analysis (multi-jets + ET)

～　　　 Signal events topology

Since all squarks are very heavy,the important signal process is the gluino pair production. Once the gluino is produced, it decays into a neutral/charged wino by emitting two quarks. As a result, its signal topology is multi-jets + ET.The mass difference between the neutral and charged wino is about 160MeV [J. L. Feng, T. Moroi, L. Randall, M. Strassler, S. f. Su, PRL83, 1999], &the charged wino eventually decays into a neutral wino by emitting one soft pion, though this pion is hardly detected in a usual manner. [B. Bhattacherjee, B. Feldstein, M. Ibe, S. M., T. Yanagida,arXiv:1207.5453.]

/

Gluino

Gluino

jet jet

jet

jet

Wino

Wino

No signal has been detected, so that some parameter region in Pure Gravity Mediation model has been excluded 7TeV: mGluino > 1TeV & mWino > 300GeV

14TeV: mGluino > 2.3TeV mWino > 1 TeV

14/17

10cm30cm

50cm

100cm

Wino dark matter detections at LHC～ Hunting for disappearing chargino tracks

～　　　 Signal events topology When at least one chargino exists in the final state of gluino pair production, it may be possible to detect the charged track caused by the chargino. This chargino eventually decays after traveling ～ 10 cm, so that the track can be detected as a disappearing track.[S. Asai, T. Moroi, T. Yanagida, PLB664, 2008] At present, TRT is used to find the track. Since TRT is 1m away from the beam pipe, the current limit is not stronger than that of conventional one. If more inner detectors is used in near future, the limit will be much stronger. [B. Bhattacherjee, B. Feldstein, M. Ibe, S. M., T. Yanagida,arXiv:1207.5453.]

The charged track of chargino has notbeen observed, so that some parameter region of the model has been excluded. 7TeV: Weaker than conventional one

14TeV: mGluino < 2.5 will be explored.

15/17

Wino dark matter detections at LHC～ Direct production of the Wino dark mater

～　 EW interaction at LHCWhen the gluino is too heavy to be produced at the LHC, we have to consider the direct production of the Wino through EW interactions. Several production processes are considered so far, for example,

(i) Wino production with a jet. [M. Ibe, T. Moroi, T. Yanagida, PLB644, 2007]

(ii) Wino production via VBF. [B. Bhattacherjee, B. Feldstein, M. Ibe, S. M., T. Yanagida, arXiv:1207.5453]

Since the cross sections of these processes are smaller than that of the gluino pair production, to find the chargino track is mandatory to extract the signal from SM BG. Estimation of the BG is difficult without use of real data.

16/17

g

q

q

q

qq

q

q

W

W

W

WinoWino

Wino

WinoWino

(1-jet)

(VBF)

(1 jet): Cross section is not so small. BG against the track is large?

(2jets): Cross section is very small. The BG is expected to be small.

• From both viewpoints of cosmology & particle physics, the neutral Wino dark matter is now understood as one of attractive candidates for dark matter.

• There is a simplest SUSY model behind the Wino dark matter, that is the pure gravity mediation of the SUSY breaking, which seems to be consistent with present LHC results as well as cosmological observations.

• It is interesting to carefully consider indirect detection signals because the annihilation cross section of Wino is not suppressed (even if its mass is ～ 1TeV) due to the Sommerfeld enhancement. Current limit is mwino > 0.3TeV.

• LHC currently gives limits on Wino and gluino masses to m gluino > 1TeV & mwino > 0.3TeV. Find tracks of chargino will be important in the future for both the gluino pair production and direct production of the Wino.

Summary

17/17

Backup

Properties of the Wino

1. Thermal production m < 2.7 TeV

2. Non-thermal production

(Wh2)NT = 0.16(m/300 GeV)(TR/1010 GeV)

For the successful leptogenesis, 　 TR > 109.5 GeV m < 1 TeV

Neutral wino mass

Charged wino mass

Hisano, S.M., Nagai, Saito, Senami, PLB646 (2007).

1000500200 300150 700

160

165

170

Mass difference between neutral & charged winos.

Charged wino is highly degeneratedwith neutral wino in their masses.

Dm ～ 165 MeV when m = 0.1-1 TeV

Charged wino decays into a neutralwino by emitting a (soft) pion.

c+ c0 + p+ (Decay length ～ 5 cm)

Disappearing track at the LHC!

BU-2

mgluino/mwino > 3

SI scattering X-sectionbetween wino & p(n) is O(10–47 ) cm2.

Annihilation X-sectioninto W bosons is 10–23 -10–24 cm3/s(Sommerfeld enhanced)

Gluino mass

Wino cross sections

Wino

Gluino

Bino

(mgluino/mbino ～ 3)

Because of the higgsinothreshold contribution,L, the relation betweenGluino, Wino, and Binomasses is changed from the conventional anomaly mediation model such as

Hisano, Ishiwata, NagataPLB690 (2010)

Hisano, Matsumoto, Nojiri, PRL92 (2004)

BU-3Properties of the Wino

Cross section: J. Hisano et al., PRL92, 031303 (2004) A. Hryczuk et al., JHEP1201, 163 (2012) Anti-proton: O. Adriani et al., PRL105, 121101 (2010) C. Evoli et al., arXiv:1108.0664. Gamma-ray: M. Ackermann et al., PRL107, 241302 (2011) A. Charbonnier et al., Mon. Not. R. Astron. Soc..418, 1526 (2011) CMB (Recombination): J. Hisano at al., PRD83, 123511 (2011) G. Hutsi et at., Astron. Astrophys. 535, A26 (2011)

Anti-proton: Currently large uncertainties from CR propagations. The situation will be improved at the AMS-02 experiment. (850 days PAMELA data. Assuming 1yr data taking with A eff = 0.25 m2 sr using DRAGON code @ AMS-02)

Gamma-ray: From (Classical & Super-faint) dSphs with 2yrs data. ∃Uncertainties because of DM profiles inside dSphs.

CMB (Recombination): DM annihilation affects the recombination history. Astrophysical uncertainties are very small.

Ibe, Matsumoto, Yanagida, PRD85, (2012)

BU-4

Gluino pair production (w/o charged tracks): Signal is multiple jets with large missing energy. ATLAS collaboration, ATLAS-CONF-2012-033. CMS collaboration, CMS PAS SUS-12-002. Gluino pair production w/ charged tracks: Signal is multiple jets with large missing energy and charged disappearing track at the TRT. ATLAS collaboration, arXiv:1202.4847. ATLAS collaboration, ATLAS-CONF-2012-034. Direct production of charged wino w/ tracks: Signal is mono/two jets with missing energy and charged disappearing track at the TRT. Ibe, et.al., PLB644, 355 (2007). http://atlas.kek.jp/sub/documents/jps201203/.

Gluino pair production (without charged tracks): Typical SUSY signal. Signal cross section (times acceptance) obtained using 11 categories of kinematical selections.

Gluino pair production with charged tracks. It does not provide the most severe bound for the TRT is currently used. If SCT is used, it will give the severest one.

Direct production of charged wino with their tracks. Signal can be detected even if the gluino is beyond the reach of the LHC experiment. No official result reported yet. LEP bound is only the one currently available, which is from the radiative return process of the wino pair production.

Bhattacherjee, Ibe, Matsumoto, Yanagida, in preparation.

BU-5