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Closing in on mass-degenerate dark matter scenarios with antiprotons and direct detection On the complementarity of direct and indirect detection Stefan Vogl with Mathias Garny (DESY), Alejandro Ibarra and Miguel Pato (TUM) to appear soon S.

SLIDE 1

Closing in on mass-degenerate dark matter scenarios with antiprotons and direct detection

On the complementarity of direct and indirect detection Stefan Vogl with Mathias Garny (DESY), Alejandro Ibarra and Miguel Pato (TUM) to appear soon

S. Vogl (TU München)

PASCOS 2012 8 June 2012 1 / 15

SLIDE 2

Outline

Introduction Particle Physics Framework Relic Density Indirect Detection Direct Detection Results Conclusion

S. Vogl (TU München)

PASCOS 2012 8 June 2012 2 / 15

SLIDE 3

Why consider compressed mass spectra?

Lets consider the case when the dark matter particle χ and the next to lightest beyond the Standard Model particle η have a similar mass ∆m = mχ − mη mχ.

Colliders

minimal transverse momentum pT is required to distinguish jet pT ≈ ∆m low sensitivity to compressed mass spectra

S. Vogl (TU München)

PASCOS 2012 8 June 2012 3 / 15

SLIDE 4

Why consider compressed mass spectra?

Lets consider the case when the dark matter particle χ and the next to lightest beyond the Standard Model particle η have a similar mass ∆m = mχ − mη mχ.

thermal production

for mη

mχ ≈ 1.2 coannihilations become important

S. Vogl (TU München)

PASCOS 2012 8 June 2012 3 / 15

SLIDE 5

Why consider compressed mass spectra?

Lets consider the case when the dark matter particle χ and the next to lightest beyond the Standard Model particle η have a similar mass ∆m = mχ − mη mχ.

Indirect Detection

compressed mass spectra exhibit very characteristic features annihilation rates are enhanced for small ∆m huge astrophysical uncertainties

S. Vogl (TU München)

PASCOS 2012 8 June 2012 3 / 15

SLIDE 6

Why consider compressed mass spectra?

Lets consider the case when the dark matter particle χ and the next to lightest beyond the Standard Model particle η have a similar mass ∆m = mχ − mη mχ.

Direct Detection

scattering rates are enhanced for small ∆m less astrophysical uncertainties than in Indirect Detection good experimental limits

S. Vogl (TU München)

PASCOS 2012 8 June 2012 3 / 15

SLIDE 7

Why consider compressed mass spectra?

Lets consider the case when the dark matter particle χ and the next to lightest beyond the Standard Model particle η have a similar mass ∆m = mχ − mη mχ.

Direct Detection

scattering rates are enhanced for small ∆m less astrophysical uncertainties than in Indirect Detection good experimental limits But: We need to specify the model in order to compare observables.

S. Vogl (TU München)

PASCOS 2012 8 June 2012 3 / 15

SLIDE 8

Particle Physics Framework

Begin with the SM and add news physics

Particles

Majorana fermion χ as dark matter a scalar η as the next to lightest beyond the Standard Model particle

Assign charges

χ is a singlet under SU(3) × SU(2) × U(1) η is a triplet under SU(3) and (for simplicity) a singlet under SU(2) u,d,s or b flavor quantum number for η

Interactions

a Yukawa interaction with the quarks: Lint = f ¯ χqRη

S. Vogl (TU München)

PASCOS 2012 8 June 2012 4 / 15

SLIDE 9

Particle Physics Framework

Begin with the SM and add news physics

Particles

Majorana fermion χ as dark matter a scalar η as the next to lightest beyond the Standard Model particle

Assign charges

χ is a singlet under SU(3) × SU(2) × U(1) η is a triplet under SU(3) and (for simplicity) a singlet under SU(2) u,d,s or b flavor quantum number for η

Interactions

a Yukawa interaction with the quarks: Lint = f ¯ χqRη Notice: similar to SUSY with light squarks

S. Vogl (TU München)

PASCOS 2012 8 June 2012 4 / 15

SLIDE 10

thermal freeze out

all particles are in thermal equilibrium in the early Universe when temperature T ≪ mχ dark matter can’t be produced anymore → dark matter freezes out

S. Vogl (TU München)

PASCOS 2012 8 June 2012 5 / 15

SLIDE 11

Coannihilations

for ∆m

mχ 1.2 more particles need to be included in the Boltzmann

equation we use MicrOMEGAS for the calculation of the relic density specifying mχ and ∆m yields constraint on f Example: Coupling to u and mχ/mη = 1.1

100 200 500 1000 2000 5000 1 104 10 4 0.001 0.01 0.1 1 10

m Χ GeV f

for mχ smaller that a certain scale the relic density can not be obtained

S. Vogl (TU München)

PASCOS 2012 8 June 2012 6 / 15

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Majorana fermions annihilating into light quarks

thermally averaged cross section σannv can be expanded as σannv = a + bv 2 + O(v 4) consider annihilations into quarks s-wave annihilation is suppressed by chirality σannv ≈ a ≈

p-wave suppressed by velocity σannv ≈ v 2 ≈ 10−6

S. Vogl (TU München)

PASCOS 2012 8 June 2012 7 / 15

SLIDE 13

Lifting the chirality suppression

the suppression can be lifted by the emission of a boson, i.e. γ, W±, Z or a gluon

χ0

¯ u η g η χ0

u

the fragmentation of the gluon increases the production of antiprotons

S. Vogl (TU München)

PASCOS 2012 8 June 2012 8 / 15

SLIDE 14

Constraints from Antiprotons

the ¯ p/p ratio measured by Pamela constrains σv main uncertainty: halo model and cosmic ray propagation Example: mη/mχ = 1.1

10−26 10−25 10−24 10−23 10−22 10−21 10−20 102 103 104 σv(χχ → gu¯ u) [cm3/sec] mDM [GeV] σv(χχ → gu¯ u) MIN MED MAX excluded from PAMELA ¯ p/p Isothermal NFW Einasto

S. Vogl (TU München)

PASCOS 2012 8 June 2012 9 / 15

SLIDE 15

Dark Matter Nucleon Scattering

dark matter nucleon scattering is induced microscopical by scattering of quarks and gluons in the nucleus

χ u η χ u

interactions can be described in terms of effective Lagrangian suppression scale Λ = m2

η − (mχ + mq)2

compressed spectrum → small Λ recoil rate is enhanced uncertainties: astrophysics (mainly neglected here) and composition of the nucleon

S. Vogl (TU München)

PASCOS 2012 8 June 2012 10 / 15

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Putting everything together

S. Vogl (TU München)

PASCOS 2012 8 June 2012 11 / 15

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The Direct Detection Plane

ucoupling m Ηm Χ1.1 thermal relic antiprotons direct detection

102 103 104 1046 1045 1044 1043 1042 1041 1040

m Χ GeV Σp

SI cm 2

S. Vogl (TU München)

PASCOS 2012 8 June 2012 12 / 15

SLIDE 18

The Indirect Detection Plane

100 200 500 1000 2000 5000 1 104 10 32 10 30 10 28 10 26 10 24

m ΧGeV Σv cm 3 s1

S. Vogl (TU München)

PASCOS 2012 8 June 2012 13 / 15

SLIDE 19

Which constraint is strongest?

S. Vogl (TU München)

PASCOS 2012 8 June 2012 14 / 15

SLIDE 20

Conclusions

compressed mass spectra lead to enhanced signals for dark matter detection experiments probes region of parameter space inaccessible at colliders direct detection experiments are cutting into the parameter space allowed by thermal production

S. Vogl (TU München)

PASCOS 2012 8 June 2012 15 / 15

SLIDE 21

Backup

S. Vogl (TU München)

PASCOS 2012 8 June 2012 15 / 15

SLIDE 22

Backup

S. Vogl (TU München)

PASCOS 2012 8 June 2012 15 / 15

SLIDE 23

Backup

S. Vogl (TU München)

PASCOS 2012 8 June 2012 15 / 15