Oct 14, 2013 ... Probing interactions within the dark matter sector via extra radiation contributions
@ DSU, Trieste. 2. Motivation. Can we estimate how large is ...
Probing interactions within the dark matter sector via extra radiation contributions Roberto A. Lineros R. IFIC-CSIC/U. Valencia and MULTIDARK fellow
In collaboration with U. França, J. Palacio and S. Pastor Based on Phys. Rev. D 87, 123521 (2013), 1303.1776 and work in progress
Motivation
Can we estimate how large is the dark (matter) sector?
14/10/2013
Probing interactions within the dark matter sector via extra radiation contributions @ DSU, Trieste
2
Outline
14/10/2013
●
Introduction
●
Relativistic species in the Early Universe
●
WIMP dark matter
●
A connexion between WIMP and Neff
●
Conclusions
Probing interactions within the dark matter sector via extra radiation contributions @ DSU, Trieste
3
The history of the Universe
14/10/2013
Probing interactions within the dark matter sector via extra radiation contributions @ DSU, Trieste
4
Relativistic species in the Early Universe
Candidates for Dark Radiation SM neutrino contribution
● ● ●
14/10/2013
Sterile neutrinos Lepton asymmetries Neutrino reheating
Probing interactions within the dark matter sector via extra radiation contributions @ DSU, Trieste
5
Relativistic species in the Early Universe Planck 2013 results Arxiv: 1303.5076
SM neutrino contribution
14/10/2013
Probing interactions within the dark matter sector via extra radiation contributions @ DSU, Trieste
6
Dark Matter
Observations supporting the Dark Matter hypothesis ● ● ● ●
14/10/2013
Dynamics of clusters and galaxies Structure formation CMB anisotropies Baryon Acoustic Oscillation
Probing interactions within the dark matter sector via extra radiation contributions @ DSU, Trieste
7
WIMP dark matter ●
Big Bang thermal relic
●
Correct relic abundance for ~ 1 pb · c
14/10/2013
●
Mass in GeV-TeV range
●
Many searches strategies
Probing interactions within the dark matter sector via extra radiation contributions @ DSU, Trieste
8
WIMP dark matter Relic abundance Indirect detection SM
DM
SM
Direct detection
DM
“production” at colliders 14/10/2013
Probing interactions within the dark matter sector via extra radiation contributions @ DSU, Trieste
9
WIMP dark matter Relic abundance Indirect detection SM +DS
Direct detection
DM
Interaction with the Dark Sector
DM
SM +DS
“production” at colliders 14/10/2013
Probing interactions within the dark matter sector via extra radiation contributions @ DSU, Trieste
10
WIMPs and Dark Radiation Nothing forbids that WIMPs can have interactions with the Dark Sector
Dark Sector Visible Sector
very light states WIMP
SM particles heavy states
Both sectors are in thermal equilibrium only if WIMPs do
14/10/2013
Probing interactions within the dark matter sector via extra radiation contributions @ DSU, Trieste
11
WIMPs and Dark Radiation Indeed, temperatures for WIMP freeze-out and the DS decoupling are related:
allowing us to explore the contribution of relativistic dof from the Dark Sector in the Early Universe:
N dark gauge bosons 14/10/2013
+3 dark fermions
Probing interactions within the dark matter sector via extra radiation contributions @ DSU, Trieste
12
N dark gauge bosons ~3 TeV
~100 GeV – 2 TeV
~10 GeV
14/10/2013
Probing interactions within the dark matter sector via extra radiation contributions @ DSU, Trieste
13
+3 dark fermions ~100 GeV – 2 TeV
~10 GeV
14/10/2013
Probing interactions within the dark matter sector via extra radiation contributions @ DSU, Trieste
14
A prototype particle model A possible realization of the idea is:
Scalar DM with a SU(N) symmetry
14/10/2013
Probing interactions within the dark matter sector via extra radiation contributions @ DSU, Trieste
15
Scalar DM + U(1)
Indirect detection cross section
14/10/2013
Direct detection cross section
Probing interactions within the dark matter sector via extra radiation contributions @ DSU, Trieste
16
Scalar DM + SU(N)
Indirect detection cross section
14/10/2013
Direct detection cross section
Probing interactions within the dark matter sector via extra radiation contributions @ DSU, Trieste
17
Fermion DM + U(1)
It also works for fermion DM (+ scalar singlet) + SU(N) Indirect detection cross section 14/10/2013
Direct detection cross section
Probing interactions within the dark matter sector via extra radiation contributions @ DSU, Trieste
18
Conclusions ●
The interactions present only in the Dark Sector can be observed
●
The latest results on Neff allow a maximum of 20 dark gauge bosons for TeV WIMPs and 13 for ~100 GeV WIMPs
●
WIMP annihilations in DS reduce the signal on indirect and direct searches allowing to surpass current exclusion zone
14/10/2013
Probing interactions within the dark matter sector via extra radiation contributions @ DSU, Trieste
19
Thanks for you attention
14/10/2013
Probing interactions within the dark matter sector via extra radiation contributions @ DSU, Trieste
20
Backup slides
14/10/2013
Probing interactions within the dark matter sector via extra radiation contributions @ DSU, Trieste
21
Relativistic dof of the SM PDG. Big-Bang Cosmology
14/10/2013
Probing interactions within the dark matter sector via extra radiation contributions @ DSU, Trieste
22
14/10/2013
Probing interactions within the dark matter sector via extra radiation contributions @ DSU, Trieste
23
