CosPA 2016

Session

Dark matter

28 Nov 2016, 14:00

4002 (SNH)

Conveners

Dark matter

• Victor Flambaum (University of New South Wales)

Dark matter

• Giorgio Busoni

Dark matter

• Yi Cai

Dark matter

• pyungwon ko (Korea Inst. for Advanced Study (KIAS))

Dark matter

• Robert Foot

Dark matter

• Juan Herrero Garcia (University of Adelaide - CoEPP)

100. Dark matter searches in LUX

Claudio Frederico Pascoal da Silva (LIP Coimbra)

28/11/2016, 14:00

The Large Underground Xenon (LUX) is a dark matter experiment searching for direct evidence of Weakly Interacting Massive
Particles (WIMPs), a favored dark matter candidate. It is a 250 kg active mass dual-phase xenon time projection chamber operating at the Sanford Underground Research Facility in USA. The results from the second and final science run with a total of 332 live days of...

67. Status of COSINE experiment.

Pushparaj Adhikari (Sejong University)

28/11/2016, 14:20

The COSINE experiment is a joint collaboration between the KIMS-NaI and the DM-Ice NaI(Tl) experiments to prove or refute DAMA/LIBRA's annual modulation result with the same NaI(Tl) crystals. The first phase of the experiment consisting of ~106 kg of NaI(Tl) crystals and ~2000 liters of liquid scintillator as an active veto has started at the Yangyang underground laboratory in Korea.The...

37. Indirect searches of TeV Dark Matter at the Galactic Center

Viviana Gammaldi (SISSA)

28/11/2016, 14:40

I will discuss several aspects of the indirect search of Dark Matter (DM) at the Galactic Center (GC). I will show that the gamma-ray flux observed by HESS from the J1745-290 GC source is well fitted as the secondary gamma-rays photons generated from DM annihilating into Standard Model particles in combination with a simple power-law background. The model independent fits are performed for...

82. First Results of the GPS.DM Observatory: Search for Dark Matter and Exotic Physics with Atomic Clocks and GPS Constellation

Benjamin Roberts (University of New South Wales)

28/11/2016, 15:00

Despite the overwhelming cosmological evidence for the existence of dark matter, and the considerable effort of the scientific community over decades, there is no evidence for dark matter in terrestrial experiments.
The GPS.DM observatory uses the existing GPS constellation as a 50,000 km-aperture sensor array, analysing the satellite and terrestrial atomic clock data for exotic physics...

50. Improved constraints on annihilating dark matter from cosmic-ray antiprotons

Martin Stref (Montpellier University)

28/11/2016, 15:20

Local measurements of Galactic cosmic-ray antiprotons are known to provide constraints on the properties of annihilating cold dark matter (CDM). It is also known that CDM candidates generically lead to the structuring of matter on scales much smaller than typical galaxies. This clustering translates into a very large population of subhalos in galaxies, which induces an enhancement of the...

117. p-wave Annihilating Dark Matter from a Decaying Predecessor and the Galactic Centre Excess

Jonathan Cornell (McGill University)

28/11/2016, 16:10

Dark matter (DM) annihilations have been widely studied as a possible explanation of excess gamma rays from the galactic centre seen by the Fermi-LAT. However, most such models are in conflict with constraints from dwarf spheroidals. Motivated by this tension, in this talk I will show that p-wave annihilating dark matter can easily accommodate both sets of observations due to the lower DM...

73. Semi-Annihilation and Dark Matter Indirect Detection

Yi Cai (The University of Melbourne)

28/11/2016, 16:30

Semi-annihilation is a generic feature in dark matter theories with symmetries beyond Z2. We investigate some examples with either single- or multi- component dark sectors where semi-annihilation affects the phenomenology substantially. We also present a systematic tool to study models with semi-annihilation.

92. Dark Forces in the Sky: Signals from Z' and the Dark Higgs

Nicole Bell (University of Melbourne)

28/11/2016, 16:50

We consider the indirect detection signals for models containing a fermionic DM candidate, a dark gauge boson, and a dark Higgs field. Compared with a model containing only a dark matter
candidate and vector mediator, the addition of the scalar provides a mass generation mechanism for the dark sector particles which, in some cases, is required in order to avoid unitarity violation at high...

105. The Dark Matter Interpretation of the Gamma-Ray Excess at the Galactic Centre

Hamish Clark (University of Sydney)

28/11/2016, 17:10

An excess of gamma rays has been observed at the centre of the Galaxy. While dark matter
annihilation within the Milky Way’s halo has been shown to provide a good fit to the observed excess, evidence has recently arisen to suggest that the excess is emitted by a large number of point sources, such as millisecond pulsars. In this talk I present recent results that investigate gamma rays...

121. Global fits of the scalar singlet model using GAMBIT

James McKay (Imperial College London)

29/11/2016, 14:00

I will present the latest results for global fits to the Higgs portal scalar singlet extended standard model using complementary probes of dark matter. In doing so I will introduce the new global and modular beyond the standard model inference tool (GAMBIT) which is used to achieve these results in a statistically consistent and modular way. I will also demonstrate the flexibility and...

43. Effective vector and fermion Higgs portal: A global study with GAMBIT

Mr Ankit Beniwal (University of Adelaide (AU))

29/11/2016, 14:20

We perform a global study of the effective vector and fermion Higgs portal models of dark matter (DM) using the Global And Modular Beyond-the-Standard-Model Inference Tool (GAMBIT) package. Within the effective field theory (EFT) approach, DM communicates with the Standard Model (SM) Higgs boson via an operator of the form $\mathcal{O}_{\mathrm{DM}} H^\dagger H$. For the fermion models, we...

111. Evaporation on Gev-ish DM in the Sun

Giorgio Busoni

29/11/2016, 14:40

We analyse the effect of evaporation on Dark Matter in the Sun, considering velocity and momentum suppressed cross sections. We check which best-fit points of 1605.06502 are affected by evaporation.

84. Plasma Dark matter direct detection

Dr Robert Foot (COEPP)

29/11/2016, 15:00

Dark matter might exist in the Milky Way as a dark plasma. Such dark matter arises
in models where dark matter originates from a hidden sector featuring a massless ‘dark photon’, including mirror dark matter. In such a scenario, the implications for direct detection experiments are very different from the more commonly studied case of WIMP dark matter. In particular electron recoils can be...

62. Halo-independent tests of dark matter direct detection signals

Dr Juan Herrero Garcia (University of Adelaide - CoEPP)

29/11/2016, 15:20

I will discuss halo-independent tests of direct detection signals that we have derived in recent works. In the first part [1502.03342 (elastic scattering) and 1512.03317 (inelastic)], I will discuss a halo-independent lower bound on the DM capture rate in the Sun from a direct detection signal, with which one can set limits on the branching ratios into different channels from the absence of a...

70. New effects of dark matter which are linear in the interaction strength

Prof. Victor Flambaum (University of New South Wales)

29/11/2016, 16:10

Low-mass boson dark matter particles produced after Big Bang form classical field and/or topological defects. In contrast to traditional dark matter searches, effects produced by interaction of an ordinary matter with this field and defects may be first power in the underlying interaction strength rather than the second power or higher (which appears in a traditional search for the dark...

78. Searching for dark matter and exotic bosons with atoms, molecules and ultracold neutrons

Yevgeny Stadnik (University of New South Wales)

29/11/2016, 16:30

We propose new schemes for the direct detection of dark matter and exotic bosons in experiments involving atoms, molecules and ultracold neutrons. Dark matter, which consists of low-mass bosons (such as axions, pseudoscalars or scalars), can readily form an oscillating classical field that survives to reside in the observed galactic dark matter haloes if these particles have sufficiently low...

114. Quantum and Classical Behaviour of Axion Dark Matter

Prof. Mark Hertzberg (Tufts University)

29/11/2016, 16:50

It is understood that in free bosonic theories, the classical field theory accurately describes the full quantum theory when the occupancy numbers of systems are very large. However, the situation is less understood in interacting theories, especially on time scales longer than the dynamical relaxation time. Recently there have been claims that the quantum theory of dark matter axions deviates...

158. A dark matter model with Dirac neutrino masses

Seungwon Baek

29/11/2016, 17:10

Tiny neutrino masses can be obtained if right-handed neutrino masses charged under a global U(1) symmetry and a second Higgs doublet which is also charged under the U(1) obtains tiny vacuum expectation value.
Due to the symmetry Majorana mass terms of the right-handed neutrinos are not allowed and the usual seesaw mechanism does not work.
We can also introduce dark matter candidates whose...

63. Particle Physics Models for DM-DR interactions

pyungwon ko (Korea Inst. for Advanced Study (KIAS))

01/12/2016, 14:00

This talk will be based on two recent preprints:
arXiv:1608.01083
arXiv:1609.02307

54. Triplet-Quadruplet Fermionic Dark Matter

Zhao-Huan Yu (University of Melbourne)

01/12/2016, 14:20

We explore a dark matter model extending the standard model particle content by one fermionic SU(2)_L triplet and two fermionic SU(2)_L quadruplets, leading to a minimal realistic UV-complete model of electroweakly interacting dark matter which interacts with the Higgs doublet at tree level via two kinds of Yukawa couplings. After electroweak symmetry breaking, the physical...

61. Right-handed neutrino dark matter under the B-L gauge interaction

Kunio Kaneta

01/12/2016, 14:40

Right-handed neutrinos (RHNs) are widely considered as an convincing new particle that can address various issues in the standard model (SM) such as the origin of neutrino mass, the existence of dark matter, and baryon asymmetry of the universe.
On the other hand, the gauge principle plays a key role to understand nature, which is empirically supported by the success of the SM so far.
In the...

106. Probing mixed complex scalar WIMP dark matter

Akiteru Santa (University of Toyama)

01/12/2016, 15:00

We discuss phenomenology of models extended by introducing
an isospin doublet scalar and a complex singlet scalar.
In such models, the lighter state of mixed neutral scalars can be WIMP candidate.
We point out that some WIMP mass regions are consistent with results of dark matter searches
as well as the limit on the dark matter relic density.
We show that these allowed regions can be...

113. Relic Abundance in Secluded Dark Matter Scenario with Massive Mediator

Masato Yamanaka (Kyoto Sangyo University)

01/12/2016, 16:10

The relic abundance of the dark matter (DM) particle $d$
is studied in a secluded DM scenario, in which the $d$ number
decreasing process dominantly occurs not through the pair annihilation
of $d$ into the standard model particles, but via the $dd \to mm$
scattering process with a subsequently decaying mediator particle $m$.
It is pointed out that the cosmologically observed relic...

118. A map of the non-thermal WIMP

Chang Sub Shin (Rutgers University)

01/12/2016, 16:30

We study the effect of elastic scattering on the non-thermally produced WIMP dark matter and its phenomenological consequences. The non-thermal WIMP becomes important when the reheating temperature is well below the freeze-out temperature. In the usual paradigm, the produced high energetic dark matters are quickly thermalized due to the elastic scattering with background radiations. The relic...

99. Determining the Local Dark Matter Density

Hamish Silverwood (University of Amsterdam)

01/12/2016, 16:50

An accurate determination of the local dark matter (DM) density is crucial to interpreting data from direct detection and certain indirect detection experiments, as it is degenerate with the DM-nucleon interaction strength. Here I give an update to our ongoing project to make a determination of the local DM density. Our method uses the positions and velocities of a set of tracer stars...

95. A two component, thermal-nonthermal dark matter model with a singlet fermion and a scalar

Debasish Majumdar (Saha Institute of Nuclear Physics)

We explore a two component dark matter model with
a fermion and a scalar. In this scenario the
Standard Model (SM) is extended by a fermion, a scalar and an
additional pseudo-scalar. The fermion component is assumed to have
a global ${\rm U(1)}_{\rm DM}$ symmetry and interacts with the pseudoscalar
via a pseudo-scalar interaction while a Z$_2$ symmetry
is imposed on the other component...