Interdisciplinary Cluster Workshop on Dark Matter 2014

10 Feb 2014, 09:00 → 11 Feb 2014, 18:00 Europe/Berlin

New seminar room (MPE Garching)

Andreas Müller (Excellence Cluster Universe)

The Interdisciplinary Cluster Workshop on Dark Matter 2014 is a workshop dedicated in particular to foster new projects and collaborations in this field. Local scientists present their work in talks on these two days. Selected external scientists join this workshop.

Update 19 Dec 2013: Program available.
No registration. No fee.

Scientific Organising Committee:
Stefan Hofmann (LMU)
Alejandro Ibarra (TUM)
Eiichiro Komatsu (MPA)
Jean-Come Lanfranchi (TUM)
Andreas Müller (TUM), Chair
Jochen Weller (LMU)
Simon White (MPA)

Abstract Booklet DarkMatterWorkshop_Feb2014_AbstractBooklet_v01.pdf

Final program InterdiscClusterWS_DarkMatter_Feb2013_program_v05.pdf

Monday 10 February

09:00 → 09:45 Status and future of the CRESST experiment

CRESST (Cryogenic Rare Event Search with Superconducting Thermometers) is an experiment aimed at the direct detection of dark matter. The experiment uses scintillating CaWO4 single crystals operated at mK-temperatures to measure the recoil energy deposited by elastic WIMP (Weakly Interacting Massive Particle) nucleon scattering. By recording the heat as well as the associated scintillation light generated by an energy deposition in the crystal, CRESST is able to achieve a unique discrimination on an event-by-event level. In the data taking run from 2009 to 2011 (Run32) comprising 730kg-days of exposure a total of 67 events in the region of interest passed all cuts and were difficult to explain with contributions from common backgrounds such as alpha-, beta-, gamma-radiation or neutrons. However, the excess might be explainable by a light WIMP of the 10 GeV type or by a still unconsidered form of background. A new data taking campaign (Run33) has started in 2013 aiming at clarifying the above mentioned experimental situation. In this talk Jean will discuss the experimental details and the status of the experiment. Finally an outlook will be given towards the future EURECA (European Underground Rare Event Calorimeter Array) experiment aimed at unifying the low-temperature experiments CRESST, EDELWEISS and possibly also the US based SuperCDMS in one setup.

Speaker: Jean-Come Lanfranchi (TUM)

Slides Lanfranchi_DM2014.pdf

09:00 → 12:00 Direct detection of dark matter

Convener: Jochen Weller (LMU)

10:00 → 10:15 Coffee break

10:15 → 11:00 Direct detection of dark matter with Xenon

Ultra-sensitive detectors using the noble gas xenon in liquid form (LXe) as dark matter target have currently reached the highest sensitivity to WIMP-nucleon interactions. Larger detectors, with target masses above 1t and with an even lower radioactive background, will come online in the next year, aiming at increasing the sensitivity by another factor of 100. Marc will discuss recent results of LXe-based detectors, such as XENON, LUX, and XMASS, the developments towards the next generation detectors, and the physics reach of multi-ton LXe dark matter detectors.

Speaker: Marc Schumann (U Bern)

Slides Schumann_DM2014.pdf

11:15 → 12:00 Axion dark matter

Cold dark matter in the form of axions is very different from WIMPs with regard to cosmological production and experimental searches. The motivation for axions, experimental and astrophysical limits, and ongoing and future search strategies will be reviewed.

Speaker: Georg Raffelt (MPP)

Slides Raffelt_DM2014.pdf

12:15 → 14:00 Lunch break: Bavarian Brotzeit

14:00 → 17:15 Indirect detection of dark matter

Convener: Jean-Come Lanfranchi (TUM)

14:00 → 14:45 Searching for spectral features in the gamma-ray sky

The search for the gamma-rays which are presumably produced in dark matter annihilations is hindered by the existence of large, and still poorly understood, astrophysical backgrounds. In this talk we will emphasize the importance of sharp spectral features for the identification of a dark matter signal. We will review the status of the search of the various spectral features that arise in particle physics scenarios and we will discuss the interplay with other search strategies.

Speaker: Alejandro Ibarra (TUM)

Slides Ibarra.pdf

14:45 → 15:30 Dark matter constraints from IceCube (and beyond)

Neutrinos are helpful messenger particles to indirectly search for the decay or annihilation of dark matter particle and constrain a variety of dark matter models. The IceCube neutrino telescope measures Cherenkov light from charged particles created by the interaction of neutrinos in a cubic kilometer of Antarctic ice. Already during its construction period, IceCube has taken data that was put through a variety of analyses with focus on WIMPs in the Galactic halo, the Galactic center, dwarf galaxies and the sun. With the increasing number of deployed strings, the sensitivity especially towards lower WIMP masses gradually improved and finally put new competitive limits on the spin-dependent proton scattering cross section. The planned low-energy extension PINGU would provide improved sensitivity to dark matter and after 1 year live-time cut into possible signal regions from DAMA/LIBRA and CoGeNT.

Speaker: Christoph Raab

Slides Raab.pdf

15:30 → 16:00 Coffee break

16:00 → 16:20 Indirect dark matter detection using cosmic antideuterons – status and prospects

The search for cosmic antideuterons has been proposed as a promising and clean method to indirectly detect dark matter, due to the very small background flux from spallations expected at the energies relevant to experiments. In this talk we discuss the prospects to observe antideuterons from dark matter annihilations or decays in current and future experiments, taking into account the important correlation of the antideuteron flux with the well-measured antiproton-to-proton fraction. We also present the more recent idea to use antihelium as a channel for indirect dark matter detection.

Speaker: Sebastian Wild (TUM)

Slides Wild.pdf

16:20 → 16:45 Interpretations of the positron excess

The rise in the positron fraction that was measured by the PAMELA experiment in 2008 was recently confirmed with unprecedented precision by the AMS-02 collaboration. In this talk Anna will review the calculation of the positron fraction and discuss three possible explanations of the positron excess, namely secondary production inside supernova remnants, and electron and positron production by pulsars and by DM annihilations. Assuming a secondary positron background and an additional astrophysical source, the new AMS-02 positron data allow to derive stringent limits on annihilating and decaying dark matter.‬

Speaker: Anna Lamperstorfer (TUM)

Slides Lamperstorfer.pdf

16:45 → 17:15 DISCUSSION

Tuesday 11 February

09:00 → 15:00 Astrophysics simulations and observations

Convener: Andreas Müller (TUM)

09:00 → 09:45 Constraints on dark matter properties from intergalactic space

Matteo will review the current constraints that intergalactic medium (IGM) data can place on: 1) the coldness of cold dark matter and its small scale properties; 2) neutrino masses; 3) cosmological parameters in standard and non-standard scenarios and implications for dark matter. He will compare observational results (from high resolution and low-resolution quasar spectra) to state-of-the-art hydrodynamic simulations of the high redshift universe.

Speaker: Matteo Viel (L'Osservatorio Astronomico di Trieste)

Slides Viel.pdf

09:45 → 10:00 Coffee break

10:00 → 10:45 The core-cusp problem

Speaker: Stella Seitz (LMU)

Slides Seitz.pdf

10:45 → 11:30 Neutrino effects on structure formation

After reviewing the basics of neutrino physics in the context of cosmology, Christian will focus on neutrino effects on the large scale structure of the universe. Especially, he will discuss how the matter power spectrum and galaxy cluster abundance are altered by the total mass of the neutrinos. Along the way, predictions of the effects using linear theory as well as N-body simulations are presented. Christian will conclude by summarizing the latest observational constraints derived from various cosmological data sets including a discussion of their possible systematics.

Speaker: Christian Wagner (MPA)

Slides Wagner.pdf

11:30 → 12:00 DISCUSSION

12:00 → 13:15 Lunch break

13:15 → 14:00 Dissecting the properties of dark matter with strong gravitational lensing

The nature of dark matter and how galaxies form in the early Universe are two major issues of modern Cosmology. Observations of the Milky Way satellite galaxies have long been used as test laboratories of the Cold Dark Matter paradigm in the small non-linear regime. These have revealed a number of potential problems that could potentially be solved by baryonic feedback processes and star formation but that may also be the signature of a different physics of the dark matter. As detecting satellite galaxies and measuring their properties can be observationally challenging, most of the observations have been limited to the Local Group, which may not necessarily be a fair representation of the Universe. Strong gravitational lensing allows us to detect low-mass dark matter satellites beyond the Local Universe and provides therefore an excellent tool to study the properties of dark matter while investigating major issues in the field of galaxy formation and evolution.

Speaker: Simona Vegetti

Slides Vegetti.pdf

14:00 → 14:45 Looking for dark matter substructure

The standard cold dark matter (CDM) paradigm predicts a hierarchy of structure down to very small scales (of order the mass of the Earth). Detecting this substructure would not only vindicate the CDM framework, but also potentially allow for a measurement of the free-streaming scale of the dark matter particles, elucidating their production mechanism. Fabian will discuss possible avenues for detecting the substructure, both within the Milky Way halo and other galaxies, purely through its gravitational interactions.

Speaker: Fabian Schmidt (MPA)

Slides Schmidt.pdf

14:45 → 15:00 DISCUSSION

15:00 → 15:30 Coffee break

15:30 → 18:00 Particle physics theory

Convener: n.n.

15:30 → 16:15 Theory of SUSY dark matter

Some of the best motivated dark matter candidates appear in supersymmetric (SUSY) extensions of the standard model. The motivation and primordial production mechanisms of these candidates will be reviewed along with the impact of cosmological constraints and new LHC limits on SUSY models.

Speaker: Frank Steffen (MPA)

16:15 → 17:00 Particle-genesis in the hot early Universe: Inclusive methods

Bjoern will review recent work on the production of sterile neutrinos in the hot Universe without and with CP violation (the latter case being relevant for Leptogenesis). In the case of massive neutrinos, there are soft and collinear divergences due to radiation of weak gauge bosons in individual amplitudes, which cancel when calculating the inclusive production rates. These techniques may as well be of relevance for the production of Dark Matter particles.

Speaker: Björn Garbrecht (TUM)

17:00 → 17:45 Phenomenology of light sterile neutrinos

Light sterile neutrinos are at the center of the attention in the neutrino community due to the emergence of new anomalies in short baseline experiments and in cosmological data analyses. Antonio will review the salient phenomenological aspects and highlight the future perspectives in the hunt of these elusive particles.

Speaker: Antonio Palazzo (MPP)

Slides Palazzo.pdf

17:45 → 18:00 DISCUSSION and wrap-up