# RENATA thematic meeting on Dark Matter @ LSC

Laboratorio Subterráneo de Canfranc

### Laboratorio Subterráneo de Canfranc

Paseo de los Ayerbe S/N 22880 Canfranc-Estacion (Huesca - SPAIN)
Description

This meeting of the National Thematic Network on Astroparticle physics (RENATA) is devoted to all aspects related to the research on dark matter. The main goals are as follows:

• To provide a framework where RENATA groups can present their research lines on dark matter, both theoretical and experimental
• To remember Professor José Ángel Villar, previous coordinator of the RENATA network, a leading figure in the development of the experimental group at the University of Zaragoza and the Canfranc Underground Laboratory

The second half of the meeting will be a Workshop on the direct detection of dark matter, that will have a few general talks and contributions based on abstract submission.

The review talks will be the following:

• Leszek Roszkowski, Review of WIMPs and axions from a theoretical perspective in direct DM search
• Cristiano Galbiati, Review of experimental WIMPs search with liquid xenon and argon: present status and future prospect
• Paolo Gorla, Review of experimental search for light WIMPs: present status and future prospect
• Kim Yeongduk, Present and future status of searching for annual modulation in the framework of DM direct detection
• Bela Majarovits, Review of experimental search for axions in the framework of DM direct detection: present status and future prospects

A summary round table and discussion will close the meeting.

Organising committee:

Eduardo García Abancéns, María Luisa Sarsa and Theopisti Dafni (Univ. Zargoza)
Aldo Ianni (Laboratorio Subterráneo de Canfranc), director LSC
Mario Martínez (IFAE Barcelona), manager FPA programme
Sergio Pastor (IFIC Valencia), RENATA coordinator

Participants
• Abraham Antonio Gallas Torreira
• Aldo Ianni
• Alessandro Bettini
• Alfonso Ortiz de Solórzano
• Amparo Lopez Virto
• Antonio Bueno
• Antonio Ferrer Soria
• Antonio L. Maroto
• Béla Majorovits
• Camilla Maggio
• Carlos Muñoz
• Carlos Peña Garay
• Carmen Romo Luque
• Ciaran O'Hare
• Clara Cuesta
• Cristiano Galbiati
• Diego Gonzalez Diaz
• Domènec Espriu
• Eduard Masso Soler
• Eduardo García Abancéns
• Elisa Ruiz Chóliz
• Fernando Arqueros
• Fernando Cornet
• Francisco del Aguila
• Frank Avignone
• Gervasio Gómez
• Gloria Luzón
• Hanguo Wang
• Igor Garcia Irastorza
• Iulian Bandac
• Iván Coarasa
• Javier Pérez Pérez
• Javier Redondo
• Jorge Puimedon
• Jose Manuel Carmona
• José Ignacio Illana
• José W.F. Valle
• Juan Antonio Martinez Mora
• Juan Cortina
• Juan José Hernández Rey
• Juan José Saborido Silva
• Leszek Roszkowski
• Lluís Font
• Luciano Romero
• M.D. Rodríguez Frías
• Manel Martinez
• MANUEL AGUILAR-BENÍTEZ
• Manuel Asorey
• Manuel Masip
• Maria Martinez
• Mario E. Gómez
• Mario Martinez-Perez
• María Luisa Sarsa
• Mercedes Fatás
• Miguel A. Sánchez-Conde
• Miguel Ardid
• Miguel Escudero
• Pablo García Abia
• Paola Ferrario
• Paolo Gorla
• Patricia Villar
• Pau Novella
• Ricardo Graciani Diaz
• Roberto Santorelli
• Rocio Vilar
• Samuel Witte
• Sergio Pastor
• Susana Cebrian
• Sven Heinemeyer
• Teresa Rodrigo Anoro
• Theopisti Dafni
• Yeongduk Kim
Contact info
• Monday, 5 February
• 4:30 PM 6:45 PM
Astroparticle Physics in Spain and Europe Laboratorio Subterráneo de Canfranc

### Laboratorio Subterráneo de Canfranc

Paseo de los Ayerbe S/N 22880 Canfranc-Estacion (Huesca - SPAIN)
• 4:30 PM
Presentation of the European Astroparticle Physics Strategy 30m
• 5:00 PM
Remembering the beginning of underground physics 30m
Speaker: Frank T. Avignone (Univ. South Carolina)
• 5:30 PM
Consolidation of underground facilities for Astroparticle Physics 30m
Speaker: Alessandro Bettini (Univ. Padua & INFN)
• 6:00 PM
Round Table: status of Astroparticle Physics in Spain: numbers, facts and future 45m
• 6:45 PM 7:15 PM
Coffee Break 30m
• 7:15 PM 8:00 PM
Remembering Prof José Ángel Villar
• 8:30 PM 11:00 PM
Social dinner 2h 30m Hotel Real Villa Anayet

#### Hotel Real Villa Anayet

• Tuesday, 6 February
• 9:15 AM 11:00 AM
Dark matter studies in RENATA groups
• 9:15 AM
Dark Matter in the Sky 15m
• 9:30 AM
Search for dark matter in Antares and KM3NeT 20m

The results and prospects of dark matter search in the Antares and KM3NeT neutrino telescopes will be reviewed

Speaker: Juan José Hernández-Rey (IFIC (CSIC-UV))
• 9:50 AM
High energy neutrinos from the Sun 20m

Dark matter annihilation in the center of the Sun may imply a flux of high energy neutrinos observable at neutrino telescopes. This signal, however, faces an important background: secondary neutrinos produced in the showers of high-energy cosmic rays that reach the surface of the Sun. We argue that this Solar neutrino flux is correlated with the cosmic-ray shadow of the Sun measured by HAWC, and we show that it is well above the flux of atmospheric neutrinos.

• 10:10 AM
Recent gamma ray dark matter searches with Fermi 20m

In this talk I will briefly describe some of the most recent work I have done within the Fermi LAT collaboration on the search for dark matter. Both WIMP and axion-like particle scenarios have been explored. Dwarf galaxies, galaxy clusters and the diffuse gamma-ray background are some of the astrophysical targets used in this search. I will end by discussing my group’s ongoing research on other less explored scenarios that could still provide further and significant insight on the nature of the dark matter. I will also mention some of our planned work with the future Cherenkov telescope array (CTA).

Speaker: Miguel Sánchez-Conde (IFT UAM/CSIC)
• 10:30 AM
Unassociated Gamma-ray Sources as Targets for Indirect DM Detection with Fermi-LAT 15m

One of the predictions of the LCDM cosmological model is the hierarchical formation of structure, giving rise to DM halos and subhalos. When the latter are massive enough they retain gas (i.e. baryons) and become visible. This is the case of the dwarf satellite galaxies in the Milky Way. Yet, less massive subhalos may remain completely dark. Nevertheless, if DM particles are WIMPs, we expect them to annihilate in subhalos, producing gamma rays which can be detected with the Fermi satellite. Using the most recent point-source Fermi catalogs (3FGL, 2FHL and 3FHL), we search for DM subhalo candidates within the unassociated catalogued sources. We apply several selection criteria based on the expected properties of the DM-induced emission from DM subhalos, which allow us to significantly reduce the list of potential candidates. Then, by carefully characterizing the minimum detection flux of the instrument and by comparing our sample to predictions from the Via Lactea II (Vl-II) N-body cosmological simulation, we place conservative and robust constraints on the $\langle\sigma v\rangle-m_{DM}$ parameter space. For $\tau^+\tau^-$ channel, we put an upper limit of $4\cdot10^{-26} (10^{-25})~{cm}^3s^{-1}$ for a mass of $10~(100)~GeV$. We find it critical for this result the repopulation we made to VL-II to include low-mass subhalos below the original VL-II mass resolution. Although the constraints are roughly an order of magnitude weaker than those obtained from dwarfs with Fermi, the sensitivity reach of our method can potentially improve them by a factor $9~(3)$ for $\tau^+\tau^-~(b\bar{b})$ channel.

• 10:45 AM
Dark Matter searches in M15 galactic globular cluster 15m

The MAGIC telescopes observed the galactic globular cluster M15 for an amount of ~150 hours during 2015 and 2016. This large data set can be used to search for Dark Matter (DM) signals from this source. The interest of this work lies in the fact that globular clusters are among the oldest objects in the Universe (M15 is one of the oldest GCs in the Milky Way) and the study of their DM component and of its interaction with baryonic matter is crucial to understand their evolution and hence the evolution of the Universe as a whole.
After a deep study of GCs literature, focusing on their modelling and phenomenology, an analysis that follows the one previously carried out by the HESS and WHIPPLE experiments on the same source will be made. At a later time, the analysis can be improved by modifying the baryonic+DM model taking into account recent findings on tidal stripping and a better modelization of the DM profile.

Speaker: Camilla Maggio (Universitat Autònoma de Barcelona & CERES-IEEC)
• 11:00 AM 11:25 AM
Coffee Break 25m
• 11:25 AM 1:30 PM
Dark matter studies in RENATA groups
• 11:25 AM
Where is SUSY DM? 20m

We combine astrophysical data with LHC measurements and searches, low energy and flavor experiments to analyze the DM candidate in various SUSY incarnations. We obtain predictions for the prospects of DM direct detection experiments and LHC DM searches.

Speaker: Sven Heinemeyer (CSIC (Madrid, ES))
• 11:45 AM
Interplay of LHC SUSY searches and Dark Matter detection. 20m

The requirement that the Lightest SUSY particle (LSP) satisfies the cosmological condition to be a Dark Matter(DM) candidate imposes some relation among SUSY particles. We explore the consequences of these relations on the framework of SUSY models with Grand Unification, finding that LHC searches and DM searches can be complementary.

Speaker: Mario E. Gomez (Universidad de Huelva)
• 12:05 PM
Sterile neutrino portal to Dark Matter: The global U(1)_(B−L) case 15m

In this talk I will discuss the possibility of the dark matter being of leptonic nature within a local and a global $U(1)_{B-L}$ symmetry breaking scenario where the neutrino masses are generated via the type-I seesaw mechanism. I will argue that the thermal dark matter possibility within a local $U(1)_{B-L}$ seems unlikely due to the strong constraints from lepton and hadron colliders. However, I will show that the global $U(1)_{B-L}$ scenario remains viable. Within this model, I will detail the dark matter production in the early universe, the non-standard sterile neutrino decays, and the possible signals at indirect detection experiments.

Speaker: Miguel Escudero (IFIC-University of Valencia)
• 12:20 PM
Ultra-light vector field dark matter 20m

Bosonic fields with very small masses, around $10^{-22}$ eV have been proposed as potential dark matter (DM) candidates. Unlike standard cold dark matter (CDM) particle models, ultra-light dark matter is more adequately described in terms of coherent fields on cosmological scales. In the scalar case, these models are known to suppress structure formation on sub-galactic scales, thus alleviating some of the claimed small-scale problems of the CDM scenario.

In this talk we explore the possibility of extending the ultra-light DM scenario to vector fields. We show that despite the presence of a coherent background vector field, the model can be compatible with the observed cosmological isotropy. We study the evolution of perturbations and compare with the scalar case. We find that in the so called wave regime, ultra-light vector DM generates a non-vanishing anisotropic stress which is the source of a gravitational wave background. We analyze the corresponding spectrum and compare with the sensitivity of present a future gravity wave detectors.

Speaker: Antonio L. Maroto
• 12:40 PM
Unified Halo-Independent Formalism for Direct Detection Experiments 15m

In this talk I will present a new formalism that quite generically allows for the comparison of direct dark matter detection data in a halo-independent manner. This formalism, based on theorems from convex geometry, effectively eliminates all caveats that had limited the applicability of previously developed halo-independent methods; for example, halo-independent comparisons can now be made between putative measurements of the annual modulation and upper limits on the scattering rate in a statistically unambiguous way.

Speaker: Samuel Witte (IFIC, University of Valencia)
• 12:55 PM
Cosmogenic production of tritium in dark matter detectors 20m

The direct detection of dark matter particles requires ultra-low background conditions at energies below a few tens of keV. Radioactive isotopes are produced via cosmogenic activation in detectors and other materials and those isotopes constitute a background source which has to be under control. In particular, tritium is especially relevant due to its decay properties (very low endpoint energy and long half-life) when induced in the detector medium and because it can be generated in any material as a spallation product. Quantification of cosmogenic production of tritium is not straightforward, neither experimentally nor by calculations.
In this presentation, a method for the calculation of production rates at sea level developed and applied to some of the materials typically used as targets in dark matter detectors (germanium, sodium iodide, argon and neon) will be presented; it is based on a selected description of tritium production cross sections over the entire energy range of cosmic nucleons. Results have been compared to available data in the literature, either based on other calculations or from measurements. The obtained tritium production rates, ranging from a few tens to a few hundreds of nuclei per kg and per day at sea level, point to a significant contribution to the background in dark matter experiments, requiring the application of specific protocols for target material purification, material storing underground and limiting the time the detector is on surface during the building process in order to minimize the exposure to the most dangerous cosmic ray components.

Speaker: Susana Cebrian (Universidad de Zaragoza)
• 1:15 PM
Columnar recombination and directional nucleus reconstruction 15m

Columnar recombination is one of the most recent and intriguing ideas to overcome the neutrino floor in future dark matter experiments, performing neutrino physics through the coherent-interaction channel, or advance in fast neutron detection, with pointing accuracy.

At the moment, liquid-based detectors have been unsuccessful at finding any signature related to it, but the phenomenon is ubiquitous in gas phase and known since a century.

Despite its presence in nuclear reactions in TPCs, columnar recombination has received little-to-none attention in the context of low-energy (sub-100keV) recoiling nuclei, and nuclei in gas, more in general, except for some initial work on alpha particles (MeV-range).

We detail ongoing efforts at measuring and modelling the effect, and that are currently undergoing at IGFAE.

Speaker: Diego Gonzalez Diaz (Universidade de Santiago de Compostela (ES))
• 1:30 PM 3:00 PM
Lunch 1h 30m
• 3:00 PM 4:35 PM
Review of direct detection of dark matter: review talks I

Chaired by M. Martines, S. Pastor

• 3:00 PM
Introduction and the Underground Canfranc Laboratory 25m
Speaker: Aldo Ianni (Laboratorio Subterráneo de Canfranc)
• 3:25 PM
Dark matter on and off the beaten track 35m

I will review WIMPs and axions from a theoretical perspective in the context of direct searches for dark matter and other related experimental activities.

Speaker: Leszek Roszkowski
• 4:00 PM
Present and future status of searching for annual modulation in the framework of DM direct detection 35m

Review on annual modulation

Speaker: Kim Yeongduk (IBS Korea)
• 4:35 PM 5:00 PM
Coffee Break 25m
• 5:00 PM 6:45 PM
Review of direct detection of dark matter: review talks II

Chaired by M. Martines, S. Pastor

• 5:00 PM
Review of experimental WIMPs search with liquid xenon and argon: present status and future prospects 35m

Review on noble liquids

Speaker: Cristiano Galbiati (Princeton University)
• 5:35 PM
Review of experimental search for light WIMPs: present status and future prospect 35m

The Dark Matter problem has accompanied cosmologist and particle physicist for more than 80 years. Nowadays we have an extremely accurate model of our universe and of its expansion, the so called Hot Big Bang, but still most of the content of the universe eludes our observation. The observation of the missing matter of the universe is of compelling necessity for understanding the Universe.
In recent years the need of a wider approach to search for dark matter beyond the WIMP paradigm has became clear to the community. In particular light dark matter candidates, with masses ranging from 0.1 GeV to ~10 GeV, can give answer to the presence of matter-antimatter asymmetry also in the dark sector (asymmetric dark matter).
The research in this range of masses nowadays is dominated by solid state detectors, with cryogenic detectors currently leading the field (CRESST, CDMS). CCD particle detectors are now a mature technology and CCD based experiment (such as DAMIC) are setting competitive limits. Also gas based TPC (NEWS-G) can give relevant contributions to the field.
A review of the best performing technologies and of most recent results is given together with a glance into the perspective.

Speaker: Paolo Gorla (LNGS)
• 6:10 PM
Dark Matter Axion searches: Status and future Prospects 35m

A review on dark matter axion search experiments will be given. The exisiting haloscope experiments based on tunable cavities will be discussed. Novel approaches, like the dielectric haloscope concept that potentially could extend the sensitivity reach of dark matter axion searches towards higher masses will be introduced. The status of exisitng R&D efforts will be presented.

Speaker: Bela Majorovits (MPI for Physics)
• Wednesday, 7 February
• 8:30 AM 11:00 AM
Review of direct detection of dark matter: talks by Spanish groups

Chaired by M. Martines, S. Pastor

• 8:30 AM
Current activity and plans of the CIEMAT-DM group 25m

In 2015 the CIEMAT Dark Matter group was one of the original proponents of the DarkSide-20k Collaboration, which plans to build a 20 ton liquid argon dual-phase TPC at LNGS with data taking starting in 2021. The new collaboration gathers now most of the groups previously involved in the ArDM, DarkSide-50 and DEAP-3600 project, creating a new unified effort in the DM direct searches field with liquid argon. The experiment is planned to be the most sensitive for massive WIMPs, reaching the so-called neutrino floor.
The CIEMAT group has 6 senior members. It is active in different areas of the experiment, particularly taking a leading role in the detector construction and background assessment. At the same time, thanks also to the synergy with LSC and the mass spectroscopy division at CIEMAT, the group is responsible for the material assay campaign, which is one of the key task for the success of the experiment.
The current status and the future plans of the CIEMAT-DM group will be presented in this talk, including a brief overview of the R&D activity on the LAr technology carried out in Madrid.

Speaker: Roberto Santorelli (Centro de Investigaciones Energéti cas Medioambientales y Tecno)
• 8:55 AM
R&D for ultra-low background sensor planes 15m

The DarkSide-20k experiment at the LNGS and the NEXT experiment at the LSC are two strikingly close examples of the technology of noble-gas optical TPCs applied to rare searches. Both Dark-Side-20 (DS20) and the upgraded NEXT detector (NEXT2.0) require the detection of scintillation and electro-liuminescence light with ultra-low background detection planes, deploying SiPMs mounted in ultra-low background substrates and read out by custom, low-background front-end electronics. We hereby propose a joint R&D effort to study synergetic solutions for the development of the DarkSide-20k and NEXT2.0 sensor planes.

Speaker: Dr Paola Ferrario (DIPC)
• 9:10 AM
Testing DAMA/LIBRA result with ANAIS-112 experiment 25m

Detecting the elusive WIMPs (Weakly Interacting Massive Particles) proposed to explain the dark matter has shown to be a very challenging effort. The study of distinctive features in the WIMP signal allowing disentangling it from other backgrounds is an important asset in this search. The motion of the Earth around the Sun will produce a modulation in the dark matter interaction rate along the year, because of the change in relative velocity between WIMPs and target nuclei. DAMA/LIBRA experiment, in the Laboratory of Gran Sasso, Italy, has observed such a modulation, having all the features expected for WIMPs distributed in an isotropic and spherical halo, with a high statistical significance. Neither considered systematics are able to explain such a modulation, nor are compatible with this result other very sensitive experiments in most of the considered dark matter scenarios.
The ANAIS (Annual modulation with NaI(Tl) Scintillators) experiment aims at the confirmation or refutation of the DAMA/LIBRA signal using the same target and technique at the Canfranc Underground Laboratory (LSC). Several 12.5 kg NaI(Tl) modules produced by Alpha Spectra Inc. have been operated in Canfranc during the last years in various set-ups. All of them have shown an outstanding light collection at the level of 15 photoelectrons per keV, which allows triggering at 1 keV of visible energy, and their background has been fully characterized. The ANAIS-112 set-up consisting of nine detectors in a 3x3 matrix configuration with a total mass of 112.5 kg has been commissioned at LSC in the first semester of 2017, starting the dark matter run on August, the 3rd.
ANAIS-112 present sensitivity will allow exploring the DAMA/LIBRA singled-out WIMP parameter region at 3 sigma in 5 years of data taking. Discovery potential of ANAIS-112 in present conditions is very high if WIMPs are responsible of the DAMA/LIBRA annual modulation signal. The ANAIS-112 experimental plan is to take data for two years and in parallel, to explore possible experiment upgrading: using the same crystals but replacing the photomultiplier (PM) tubes by SiPMs or adding a liquid scintillator veto. The additional three years of data taking would require new funding.
Moreover, ANAIS will work in the next two years in the understanding of the behaviour at low energy of the scintillation quenching factor for NaI(Tl) crystals of different quality and providers, in collaboration with other international partners.

Speaker: Dr M.L. Sarsa (Universidad de Zaragoza)
• 9:35 AM
Search for low mass WIMPs with low-threshold low-background TPCs: the TREX-DM experiment 20m

The standard WIMP Dark Matter (DM) paradigm, based on the “WIMP miracle”, is now severely constrained by the negative results from direct DM experiments and the LHC. But WIMPs of particularly low masses (below 10 GeV) would produce nuclear recoils of energies below typical experimental thresholds, and so would have evaded detection so far. This type of WIMPs are still viable in the remaining non-excluded SUSY phase space, or in non-SUSY models, like the so-called asymmetric DM. Their direct experimental detection poses very particular and demanding technological challenges that are not within reach of mainstream WIMP experiments. Therefore a novel type of WIMP experiments has been recently born focused on the low mass part of the WIMP parameter space. TREX-DM is one of such projects, based on the low-threshold and low-background offered by detection in high pressure gas and Micromegas amplification structures of the microbulk type, developed as part of the T-REX project. The experiment has recently been approved by the LSC (Laboratorio Subterráneo de Canfranc) scientific committee and its installation underground is ongoing at the moment. If the background model anticipated by an extensive material screening campaign is confirmed experimentally, TREX-DM can have very competitive prospects in the new experimental landscape of the low-mass WIMP searches. The experiment should move to commissioning phase and first data taking throughout 2018.

Speaker: Gloria Luzon Marco (Universidad de Zaragoza (ES))
• 9:55 AM
Direct dark matter detection with superheated liquids 20m

Through the Multidark Consolider, the Universitat Politècnica de València (UPV) research group “Acoustics for Astroparticle Detectors” has been participating in several direct dark matter detection experiments using superheated liquids since 2011. This technique presents the advantages of being efficient to nuclear recoils, easily scalable to large volumes, cost-effective, very small (almost zero) background and some freedom in selection of active targets, as for example using Fluor compounds. In this sense, the PICO bubble chamber detectors installed at SNOLAB have provided the best constrains to proton-WIMP spin-dependent interactions. Besides this, we have also been participating in the gesyser detector MOSCAB which is being installed in LNGS. Our activities within the Collaborations are mainly related to the acoustic systems needed to discriminate signal from background. We have also developed an acoustic test-bench in UPV to better understand the technique to optimise the acoustic systems.
In the talk we will review the technique, the different detectors and results, and the prospects for the future, presenting as well our activities in the field.

Speaker: Miguel Ardid (UPV)
• 10:15 AM
DAMIC Experiment 20m

Dark matter (DM) in the sub-GeV mass range is a theoretically motivated but largely unexplored paradigm, complementing the high mass search. Such light masses are out of reach for conventional nuclear recoil direct detection experiments, but may be detected through the small ionisation signals caused by dark matter-electron scattering. Investigating Light DM is an important and natural direction to pursue in the DM search effort.

DAMIC experiment at SNOLAB employs fully-depleted charge-coupled devices *(CCD). Using the bulk silicon which composes the detector as target is expected to observe coherent WIMP-nucleus elastic scattering. Due to its low electronic readout noise allows an unprecedentedly low energy threshold that make it possible to detect silicon recoils resulting from interactions of low mass WIMPs. In addition the CCD's excellent energy and spatial resolutions, the DAMIC CCDs are well-suited to identify and suppress radioactive backgrounds, having an unrivalled sensitivity to WIMPs with masses < 6 GeV/c2 [1]. Early results motivated the construction of a 100 g detector, DAMIC100, recently installed and currently taking data, it is expected to provide results for the winter conferences. It will perform precise measurements of backgrounds (32 Si and tritium) and place dark matter limits with O(10 kg day) exposure. DAMIC had shown sensitivity to other DM candidates and had presented the most stringent direct detection constraints on hidden photon[2].

DAMIC collaboration is planning an upgrade increasing its mass to 1kg, that will be developed in the next three years DAMIC-1K[3] will search for low-mass DM in a broad range from 1 eV –few GeV with unprecedented sensitivity to DM-electron scattering and hidden-photon DM by improving by orders of magnitude the sensitivity to the ionisation signals from the scattering of dark matter particles with valence electrons. The technology to fabricate DAMIC-1K CCDs is already proven, with modest increase in area and thickness of the DAMIC detectors. Skipper design — developed, tested, and implemented by the SENSEI collaboration— will be used to reach sub-electron noise, combined with digital filtering for fast readout. DAMIC-1K will demonstrate the rejection of cosmogenic 32Si — the dominant background for SuperCDMS Si-HV — through spatial correlation of candidate events with the decay of the 32P daughter, providing a path to the exploration of low-mass DM interactions down to the Neutrino Floor.

The following plots show the DAMIC constraints and DAMIC-1K projections for the DM-electron scattering cross section σe for WIMPS and hidden photons respectively.

Speaker: Rocio Vilar Cortabitarte (Instituto de Física de Cantabria (Universidad de Cantabria -CSIC))
• 10:35 AM
Search for axions with the International Axion Observatory (IAXO) 25m

Axions are a natural consequence of the Peccei-Quinn mechanism, the most compelling solution to the strong-CP problem. Similar axion-like particles (ALPs) also appear in a number of possible extensions of the Standard Model, notably in string theories. Both axions and ALPs are very well motivated candidates for the Dark Matter, they appear in other cosmological scenarios involving inflation, dark radiation or even dark energy, and could also solve some long-standing anomalous astrophysical observations. If they exist, they would be copiously produced at the sun’s interior. A relevant effort during the last decade and a half has been the CAST experiment at CERN, the most sensitive axion helioscope to-date. The International Axion Observatory (IAXO) will be a fourth generation axion helioscope, born as a large-scale ambitious follow-up of CAST. As its primary physics goal, IAXO will look for solar axions or ALPs with a signal to background ratio of about 5 orders of magnitude higher than CAST. For this, IAXO envisions a large multibore superconducting magnet designed to optimize the axion helioscope figure of merit, extensive use of x-ray focusing optics and low background x-ray detectors. IAXO will venture deep into unexplored axion parameter space, thus having discovery potential. The first step of the project, called BabyIAXO, features a scaled-down system (but of dimensions representative of the full infrastructure), with a single-bore magnet and one full scale detection line. BabyIAXO will already enjoy competitive sensitivity (of about 2 orders of magnitude in signal-to-noise-ratio better than CAST) and will deliver relevant physics outcome.
BabyIAXO and IAXO have also potential to host additional detection setups. Most interestingly, the large magnetic volume available could be used to host haloscope-like setups to detect relic axion or ALPs potentially composing the galactic halo of Dark Matter. IAXO has the potential to serve as a multi-purpose facility for generic axion and ALP research in the next decade.

Speaker: Igor Irastorza
• 11:00 AM 11:30 AM
Coffee Break 30m
• 11:30 AM 1:00 PM
Review of direct detection of dark matter: discussion

Chaired by M. Martines, S. Pastor

Conveners: Mario Martinez-Perez (Universitat Autonoma de Barcelona (ES)) , Sergio Pastor (IFIC Valencia)