Conveners
Dark Matter, Astroparticle Physics: Session 1
- Jason Kumar (Texas A&M University)
Dark Matter, Astroparticle Physics: Session 2
- Jason Kumar (Texas A&M University)
Dark Matter, Astroparticle Physics: Session 3
- Malcolm Fairbairn
Dark Matter, Astroparticle Physics: Session 4
- Kazuki Sakurai (University of Warsaw)
Dark Matter, Astroparticle Physics: Session 5
- Daniele Teresi
- Daniele Teresi (Universitรฉ Libre de Bruxelles)
Dark Matter, Astroparticle Physics: Session 6
- Malcolm Fairbairn
Dark Matter, Astroparticle Physics: Session 7
- Felix Bruemmer (Universitรฉ de Montpellier)
Dark Matter, Astroparticle Physics: Session 8
- Oleg Lebedev (University of Helsinki)
A promising way to identify the nature of dark matter (DM) and to measure its
properties and spatial distribution is to search for the gamma rays produced in annihilation or decay of DM particles in the local Universe.
In particular, ground-based Cherenkov gamma-ray telescopes are sensitive to WIMPs of mass above ~100 GeV. The current generation of instruments, such as H.E.S.S., MAGIC and...
ANTARES, the deep-underwater Cherenkov neutrino telescope in the Northern hemisphere, has been taking data continuously since 2007. Its primary goal is the search for astrophysical neutrinos in the TeV-PeV range. Thanks to its excellent angular resolution, ANTARES has performed dedicated searches for promising neutrino source candidates and several interesting regions like the Galactic Plane...
Neutrino telescopes have a wide scientific scope both for particle physics and astroparticles. The next-generation undersea detector, KM3NeT, is currently under construction on two sites in the Mediterranean: ORCA, a dense detector located close to the French coast โnear the location of its predecessor, ANTARESโ, and ARCA, a sparse detector located close to the Italian coast. ORCA, with an...
We discuss QCD uncertainties in the modelling of the gamma-ray energy spectra from Dark-Matter (DM) annihilation in the galaxy center and beyond.
Dark Matter particles, being neutral, cannot couple directly to photons.
Photons are instead produced as the result of the fragmentation and decay of the particles the DM annihilates into.
In phenomenological studies the photons energy spectra are...
We discuss a neutrinophilic two Higgs doublet model realized by a hidden local $U(1)$ symmetry, where active neutrinos are Dirac type, and a fermionic DM candidate is naturally induced as a result of remnant symmetry. In addition, a physical Goldstone boson is arisen as a consequence of two types of gauge singlet bosons and contributes to the DM phenomenologies as well as additional neutral...
This talk introduces a novel solution to astrophysical small-scale problems, (i.e. core/cusp and too-big-to-fail) by invoking a certain class of dark matter self-annihilating processes. Such processes lead to the formation of dark matter cores at late times by considerably reducing the inner mass density of dwarf-sized halos. An important aspect of this new solution is that the...
If Dark Matter (DM) interacts with nucleons and/or electrons it can be trapped in celestial bodies. For a Neutron Star (NS), DM accumulating in the center could form a core which could further gravitationally collapse into a black hole. The requirement that such collapses do not occur gives constraints on the DM mass and interaction strength. Such phenomenon crucially depends on the amount of...
Neutron stars (NSs) are promising indirect probes for dark matter (DM), dark kinetic heating of NSs is within the reach of forthcoming infrared telescopes and only depends on the amount of accumulated DM. Inelastic DM is suppressed at tree level in direct detection experiments. Assuming that kinetic heating of NSs is only due to DM scattering and using an effective operator approach on...
XENON1T is a direct dark matter search experiment, currently taking data at the Laboratori Nazionali del Gran Sasso (LNGS), Italy, and the first multi-ton scale detector of this kind. The experiment is based on a xenon dual-phase (liquid-gas) time projection chamber with ~2000 kg of target mass (out of 3200 kg total xenon mass), exploiting both scintillation and ionization signals to...
DarkSide uses a dual-phase Liquid Argon Time Projection Chamber to search for WIMP dark matter. The talk will present the latest result on the search for low mass ($M_{WIMP} <20GeV/c^2$ ) and high mass ($M_{WIMP}>100GeV/c^2$) WIMPs from the current experiment, DarkSide-50, running since mid 2015 a 50-kg-active-mass TPC, filled with argon from an underground source. The next stage of the...
For more than 20 years the DAMA/LIBRA collaboration has reported a positive annual modulation in the low-energy detection rate of their NaI(Tl) detectors with very high C.L., that has been recently updated to 12.9$\sigma$. The interpretation of this result as a WIMP signal in standard models is, however, in strong tension with the null results of other experiments. Therefore there is an urge...
The Belle II experiment is a substantial upgrade of the Belle detector and will operate at the SuperKEKB energy-asymmetric $e^+ e^-$ collider. The accelerator has already successfully completed the first phase of commissioning in 2016 and first electron positron collisions in Belle II are expected for April 2018. The design luminosity of SuperKEKB is $8 \times 10^{35}$ cm$^{-2}$s$^{-1}$...
Sub-MeV dark matter remains unconstrained by direct detection, and there are several well-motivated candidates in this mass range. Electron recoil experiments have been proposed as a technique to detect such a light particle, but little is known about the extent of cosmological restrictions on a generic light species coupled to electrons. We study cosmological constraints on a light dark...
VERITAS is a ground-based gamma-ray observatory consisting of an array of four atmospheric Cherenkov telescopes located in southern Arizona, USA. VERITAS carries out an extensive observation program of the gamma-ray sky at energies above 0.1 TeV (VHE). The majority of the sources detected by VERITAS are active galactic nuclei, with gamma-ray emission originating in their relativistic jets. TeV...
Semi-annihilation describes non-decay processes with an odd number of external dark sector states. The canonical example is an initial state of two dark particles and a final state of one dark plus one or more standard model particles. It is a generic feature of dark matter whenever the symmetry group enforcing stability is not a discrete $Z_2$. Semi-annihilation changes the expected signals...
If dark matter annihilation is velocity dependent, then the J-factors associated with any astrophysical target depend on the full dark matter phase space distribution. We calculate these velocity-dependent J-factors for a variety of targets and a variety of choices for the velocity-dependence of DM annihilation. Significantly, we find that the choice of velocity-dependence affects the...
In some models for WIMP dark matter, radiative corrections dominate over the LO contributions in the computation of annihilation cross sections relevant for indirect detection. These corrections need to be resummed to all orders in perturbation theory for theoretical predictions to be sensible.
In this talk I will employ -and briefly review- resummation methods that are traditionally used in...
Di-lepton production at the LHC and Direct Detection (DD) limits put strong constraints on simplified DM models where the DM particle is a fermion, coupled to the SM through an extra U(1)' gauge boson, Z'. The first problem can be avoided by demanding vanishing Y'-charges for leptons (leptophobia). Then, the requirement of anomaly cancellation imposes strong and non-trivial constraints on the...
In the MSSM, light scalar top quarks are well motivated and
often contribute significantly to the neutralino dark matter
relic density. We present a new precision calculation of
stop annihilation into heavy quarks at next-to-leading order
of SUSY-QCD and with Coulomb resummation effects and discuss
the size and uncertainty of these corrections with respect
to the experimental measurement of...
The axion solution to the strong CP problem also provides a natural
dark matter candidate. If the PQ symmetry has ever been restored after
inflation, topological defects of the axion field would have formed and
produced relic axions, whose abundance is in principle calculable. Using
numerical simulations I will present a detailed study of the evolution of
axion strings and the resulting...
I consider the keV scale axino dark matter in the supersymmetricย Dine-Fischler-Srednicki-Zhitnitskyย (DFSZ) axion model.ย Theย axino dark matter is dominantly produced from freeze-in processes, and it decays into a monochromatic photon that can be measured by X-ray observations. However,ย keV scale dark matter normally has a tension with the constraints from Ly-alpha forest data.ย In this talk, I...
The mechanism of โspontaneous leptogenesisโ โ in which the matter-antimatter asymmetry is generated via motion of a scalar field coupled to the electroweak gauge bosons โ provides an interesting alternative to more traditional thermal leptogenesis models. While an axion-like field is a natural candidate for these models, the observed asymmetry requires an axion mass so large it decays shortly...
We investigate the phenomenology of fermion dark matter as an admixture of weak singlet and triplet Majorana fields. Our model can be considered as a generalization of the wino-bino scenario in supersymmetry. The dark sector interacts with the Higgs boson through a pseudo-scalar portal, thus mitigating bounds from direct detection experiments. The observed dark matter abundance is obtained...
We construct a self-interacting dark matter model that could simultaneously explain the observed muon anomalous magnetic moment. It is based on a gauged U$(1)_{L_{\mu} - L_{\tau}}$ extension of the standard model, where we introduce a pair of vector-like fermions as the dark matter candidate and a new Higgs boson to break the symmetry at the 10 MeV scale. The new gauge boson has sizable...
Todayโs standard way to calculate the thermal relic abundance of dark matter via chemical decoupling relies on the assumption that particles remain in kinetic equilibrium throughout the freeze-out process. However, is this assumption always justified?
The talk aims to address this question and discuss the consequences of more accurate treatments. Two methods are presented: One that combines...
Motivated by the possibility of enhancing dark matter (DM) self-scattering cross-section ฯ self , we have revisited the issue of DM annihilation through a Breit-Wigner resonance. In this case thermally averaged annihilation cross-section has strong temperature dependence, whereas elastic scattering of DM on the thermal bath particles is suppressed. This leads to the early kinetic decoupling of...
Dark matter axions and other highly degenerate bosonic fluids are commonly described by classical field equations. As our recent work, we evaluated the duration of classicality of a homogeneous condensate with attractive contact interactions. In their classical descriptions, such condensate persists forever. Taking into account the quantum description, however, parametric resonance causes...
We perform a search of Dark Matter (DM) subhalo candidates among unassociated catalogued sources present in the most recent Fermi-LAT point-source catalogs (3FGL, 2FHL and 3FHL). These LCDM-predicted DM subhalos are promising candidates for gamma-ray emission from WIMP annihilation in the LAT energy band. Several selection criteria are applied, based on the expected properties of the...
The freeze-out of massless particles is investigated. The effects due to
quantum statistics, Fermi-Dirac or Bose-Einstein, of all particles
relevant for the process are analyzed. Solutions of appropriate Boltzmann
equation are compared with those obtained using some popular approximate
methods. As an application of general results the relic density
of dark radiation in Weinberg's Higgs...
Dark matter could be produced at the LHC if it interacts weakly with the Standard Model. The search for dark matter can be performed directly, by looking for a signature of large missing transverse momentum coming from the dark matter candidates escaping the detector, measured against an accompanying visible object (jet, photon, boson). A broad and systematic search program covering these...
Searches in CMS for dark matter in final states with invisible particles recoiling against leptons and photons are presented. Various topologies are explored, covering several specific dark-matter production modes. The talk focuses on the recent results obtained using data collected at Run-II of the LHC.
The search for dark matter can be performed indirectly at the LHC by looking for the intermediate mediators which would couple the dark matter particles to the Standard Model. The mediator could indeed decay to jets or leptons, leading to a resonant signature which can be probed. The talk will present the results of these searches with the ATLAS detector and show their complementarity with the...
Electroweakly charged dark matter always has charged partners. The mass differences between the dark matter and the partners are not so large and the they often have rather long lifetime, which can be seen in the collider experiments as a disappearing track. Based on 1703.09675 and ongoing works, I will discuss the current and future constraints for the minimal dark matter.
We present the results of the first global likelihood study of Dark Matter Simplified Models (DMSMs) performed by the MasterCode collaboration, considering the case of spin-1 and spin-0 mediators. Our study includes the most important collider limits coming from searches at runs 1 and 2 of the LHC, as well as constraints coming from cosmological data and direct searches for dark matter.
This...
The QCD axion, as well as more general Axion-Like Particles (ALPs) represent well motivated Dark Matter (DM) candidates. We investigate the possibility that a fraction of the total Axion DM abundance is made of Primordial Black Holes (PBHs). The basic ingredient is the existence of a long-lived network of axionic domain walls attached to strings, which eventually annihilates providing an extra...
We present an economical model of WIMP dark matter in which the dark sector consists of the dark matter candidate, a fermionic singlet, and its coannhihilation partner, a fermionic SU(2) n-plet with n>=3. The dark sector is coupled to the SM Higgs boson via non-renormalizable interactions. We map the viable parameter space of this model, taking into accounts constraints from direct detection...
The Minimal Supersymmetric Standard Model (MSSM) predicts the existence of a total of four neutralinos, the lightest of which is one of the strongest cold dark matter (DM) candidates. The nature of this neutralino DM depends on the relative sizes of the bino, wino and higgsino mass parameters in the neutralino mass matrix. At the LHC, the trilepton channel, which is one of the most important...
We study novel collider signatures including the Higgs boson and dark matter. These signatures arise naturally in well-motivated models, where dark matter interacts with the Standard Model primarily via the Higgs boson.
We explore concrete examples with fermion or scalar dark matter vis-a-vis our proposed search and the existing dark sector studies at the LHC. We also comment on the...
We present the current perspectives for supersymmetric Dark Matter, in light of current and future collider and direct detection experiments, in a phenomenological Minimal Supersymmetric Standard Model scenarios with eleven parameters (pMSSM11) and in the subGUT-CMSSM, in which the input scale, $M_{in}$, at which the soft SUSY-breaking terms are universal, is treated as an additional free...
The impact of the current searches at the LHC for monojets is compared to the current limits from direct searches for dark matter (DM) in the framework of the NMSSM. The DM annihilation cross section is ten orders of magnitude larger than limits on the scattering cross section. This can be explained, if the interactions are predominantly due to Higgs exchange, since the Higgs boson couples...
