Conveners
Dark Matter, Astroparticle Physics
- Brooks Thomas (Lafayette College)
Dark Matter, Astroparticle Physics
- Jason Kumar
Dark Matter, Astroparticle Physics
- Nicole Bell (University of Melbourne)
Dark Matter, Astroparticle Physics
- Jonathan Lee Feng (University of California Irvine (US))
Dark Matter, Astroparticle Physics
- Howard Baer (University of Oklahoma)
Dark Matter, Astroparticle Physics
- Pearl Sandick (University of Utah)
Dark Matter, Astroparticle Physics
- Tracy Slatyer
Dark matter annihilation to a two-body final state is difficult to probe for many models because the dominate annihilation channel is velocity suppressed. The inclusion of gauge boson radiation in these models creates a three-body final state that lifts the suppression, allowing for a velocity-independent cross section that can dominate. This inclusion provides a means to investigate these...
Most indirect dark matter searches consider only signals from decay or two-body annihilation. I will discuss the general scenario where more than two dark matter particles participate in the annihilation process. Such processes can be greatly enhanced at low velocities, and generically have different redshift dependence than standard decay/annihilation signals. I will describe and examine the...
We will present the current results of our analyses of SUSY-QCD corrections to dark
matter annihilation cross-section in pMSSM scenarios with a light scalar quark of the third generation. Such scenarios are extremely appealing as they have not yet been ruled out by LHC searches and at the same time the lightest Higgs mass in these scenarios is predicted to be consistent with the measured...
Dwarf spheroidal galaxies (dSphs) are are exceptionally clean targets for searches for gamma rays from dark matter annihilation. Here, I will discuss a general, model-independent formalism for determining bounds on the production of photons from dark matter annihilation in dSphs. This formalism is applicable to any set of assumptions about dark matter particle physics or astrophysics. As an...
X-ray observations of clusters and galaxies have detected an unexplained X-ray emission line around 3.5 keV. This line has been the subject of many recent works due to its potential explanation as due to decaying dark matter. In particular, sterile neutrinos with a mass of 7 keV and mixing angles of $\sim10^{-10}$ provide a good fit to the data. I discuss recent work in which we exploit the...
Multiple space-borne cosmic ray detectors have detected line-like features in the electron and positron spectra. Most recently, the DAMPE collaboration reported the existence of such a feature at 1.4 TeV, sparking interest in a potential dark matter origin. Such quasi-monochromatic features, virtually free of any astrophysical background, could be explained by the annihilation of dark matter...
Non-abelian vector boson dark matter (DM), although not widely studied, offers very important phenomenological outcome. In this talk, we highlight some possibilities that can be accommodated in an $SU(2)$ extension of the the Standard Model (SM). One important feature of DM of such kind is realized via $t$-channel annihilation for relic abundance and $s$-channel direct search interaction,...
In this talk, I will show how to calculate the bound state formation cross section in this model. Unlike the usual calculations, "mono-pole" emission becomes significant, and the process emitting the longitudinal dark photon/Goldstone boson becomes very important in the annihilation processes. I will also show the numerical results.
We propose an extension of the Standard Model gauge symmetry by the gauge group U(1)_T3R in order to address the Yukawa coupling hierarchy between the third generation fermions and the first two generation fermions of the SM. We assume that only the right-handed fermions of the first two generations are charged under the U(1)_T3R. In addition to the new dark gauge boson, we have a dark scalar...
Multipartite dark sector has several motivations, one of the key issues being to evade stringent direct search bound. In this talk, we highlight some interesting phenomenological features of having two component dark matter models constituted of scalar-scalar or scalar-fermion dark matter, where the interaction between the dark matter components not only yields a larger available parameter...
Dynamical Dark Matter (DDM) is an alternative framework for dark-matter physics in which the dark sector consists of large ensembles of dark states which exhibit a broad range of masses and lifetimes. While some of the states in this ensemble must be sufficiently long-lived that they contribute to the dark-matter abundance at present time, other states in the ensemble may have far shorter...
We explore the possibility that the relic abundance of dark matter is generated in a context where the inflaton is the only mediator between the visible and the hidden sectors of our universe. Due to the relatively large mass of the inflaton field suggested by large-field inflation scenarios, such a portal leads to an extremely feeble interaction between the dark sector and the Standard Model...
The question of the nature of dark matter has become increasingly puzzling as more experiments exclude larger portions of the favored WIMP parameter space. Previous theoretical work has suggested the existence of Lightly Ionizing Particles (LIPs) with charge e·f, where e is the electron charge and f < 1. At least a part of the dark matter could consist of these LIPs. We seek to utilize data...
There is strong evidence that $\sim27\%$ of the energy density of our universe is composed of a dark matter component which has been inferred by observing its gravitational effects. Many well motivated models predict candidate particles with mass below 10 GeV which offer compelling solutions to the dark matter mystery but have yet to be experimentally detected. The Super Cryogenic Dark...
The Belle II experiment is a substantial upgrade of the Belle detector and will operate at the SuperKEKB energy-asymmetric $e^+ e^-$ collider. The design luminosity of the machine is $8\times 10^{35}$ cm$^{-2}$s$^{-1}$ and the Belle II experiment aims to record 50 ab$^{-1}$ of data, a factor of 50 more than its predecessor. From February to July of this year, the machine has completed a...
The features of the NA62 experiment at the CERN SPS – high-intensity setup, trigger-system flexibility, high-frequency tracking of beam particles, redundant particle identification, and ultra-high-efficiency photon vetoes – make NA62 particularly suitable to search for long-lived, weakly-coupled particles within Beyond the Standard Model physics, using kaon and pion decays as well as operating...
The presence of a non-baryonic dark matter component in the Universe is inferred from the observation of its gravitational interaction. If dark matter interacts weakly with the Standard Model it would be produced at the LHC, escaping the detector and leaving a large missing transverse momentum as their signature. The ATLAS detector has developed a broad and systematic search program for dark...
Searches for dark matter in various final states with invisible particles recoiling against standard model particles are presented. Various topologies and kinematic variables are explored, as well as jet substructure as a means of tagging heavy bosons. The focus of the talk is on the recent CMS results obtained using data collected in the LHC run 2.
Several models of the dark sector beyond the minimal Weakly Interacting Massive Particle paradigm are accessible at current and upcoming neutrino experiments. I present two well-motivated models to which the experiments at Fermilab are sensitive: boosted dark matter and the Higgs portal. Several regions of hadronically interacting boosted dark matter parameter space will be accessible to...
Millicharged particles (mCPs) are theoretical particles with fractional electric charge, which could constitute part of the dark matter present in the Universe and can naturally arise in dark sectors with U(1)' gauge symmetries. We report the latest constraints to the parameter space of mCPs using data from ArgoNeuT, a 0.24 ton Liquid Argon Time Projection Chamber (LArTPC), with a novel...
I will be discussing constraints on light dark matter and the effects of the astrophysical neutrino background. This will include a discussion of bremsstrahlung, the Migdal effect, and dark matter scattered by cosmic rays, as well as the effect of these processes on the background induced by coherent elastic neutrino-nucleus scattering.
Super-Kamiokande is world's largest water Cherenkov experiment, with physics studies broadly ranging from probing theories of unification with proton decay to neutrino interactions and astrophysics. Upcoming near-future upgrade of the experiment with dissolution of gadolinium will open a new window into supernovae physics. In particular, potential first detection of supernovae relic neutrinos...
We consider a model of decaying axino-like particle dark matter with lifetime around the age of the universe. Its late decay to gravitino plus axion-like particle can solve small scale problems. We will also show a distinct signature of the axion-like particle from the axino-like particle decay.
We show that both the baryon asymmetry of the universe and dark matter (DM) can be accounted for by the dynamics of a single axion-like field. In this scenario, the observed baryon asymmetry is produced through spontaneous baryogenesis—driven by the early evolution of the axion—while its late-time coherent oscillations explain the observed DM abundance. Typically, spontaneous baryogenesis via...
Axion-like particles (ALPs) produced in the core of a neutron star can convert to photons in the magnetosphere, leading to possible signatures in the soft and hard X-ray emission from these sources. We study these signatures taking the magnetar SGR 1806-20 as an example. In particular, assuming ALP emission rates from the core that are just subdominant to neutrino emission, the parameter...
The observed rapid cooling of the neutron star (NS) located at the center of the supernova remnant Cassiopeia A (Cas A) can be explained in the minimal NS cooling scenario. This consequence may be changed if there exists an extra cooling source, such as axion emission. In this work, we study the Cas A NS cooling in the presence of axion emission, taking account of the temperature evolution in...
The Milky Way halo is the brightest source of dark matter annihilation on the sky. Indeed, the potential strength of the Galactic dark matter signal can supersede that expected from dwarf galaxies and galaxy groups even in regions away from the Inner Galaxy. We present the results of a search for dark matter annihilation in the smooth Milky Way halo for $|b| > 20^\circ$ and $r < 50^\circ$...
We consider a non-exotic gauged U(1)_X extension of the Standard Model (SM), where the U(1)_X charge of a SM field is given by a linear combination of its hypercharge and Baryon-minus-Lepton (B−L) number. All the gauge and mixed gauge-gravitational anomalies are cancelled in this model with the introduction of three right-handed neutrinos (RHNs). Unlike the conventional minimal U(1)_X model,...
In fermionic dark matter (DM) models with pseudoscalar mediators, the tree-level amplitude for the DM-nucleon elastic scattering is suppressed by the momentum transfer in the non-relativistic limit. However, it is not suppressed at the loop level, and thus the loop corrections are essential to discuss the sensitivities of the direct detection experiments for the model prediction. In...
An exact spacetime parity replicates the $SU(2) \times U(1)$ electroweak interaction, the Higgs boson $H$, and the matter of the Standard Model. This "Higgs Parity" and the mirror electroweak symmetry are spontaneously broken at scale $v' = \langle{H'}\rangle \gg \langle{H}\rangle$, yielding the Standard Model below $v'$ with a quartic coupling that essentially vanishes at $v'$:...
Supersymmetry predicts a large number of scalar fields, some of which carry baryon and lepton numbers. I will discuss how fragmentation of scalar fields with an approximate U(1) symmetry into lumps is a general mechanism for primordial black hole formation. There are O(100) of such scalar fields (flat directions) in MSSM, which can naturally result in primordial black holes.
The LAr technology has strong potential to push the sensitivity for WIMP detection several orders of magnitude beyond current levels. The Global Argon Dark Matter Collaboration (GADMC) will pursue a sequence of future detectors to follow this potential. The immediate objective is the DarkSide-20k two-phase detector, currently under construction at LNGS. DarkSide-20k will have ultra-low...
The twin Higgs scenario protects the Higgs mass from large quantum corrections through symmetry partners without standard model (SM) color charge.The particles belong to a "twin" sector, related to the SM by a discrete exchange symmetry. The gauge symmetries in each sector forbid all but a few renormalizable connections between the sectors. Vectors portals, either through twin particles or...
Dark matter (DM) self-interactions affect the gravitational capture of DM in the Sun and Earth differently as a simple consequence of the differing kinematics of collisions within the two potential wells: the dominant effect of self-interactions in the Sun is to provide an additional channel for capture, while the dominant effect in the Earth is to eject previously captured DM. I will discuss...
The observed flattening of rotation curves is usually considered strong evidence for the existence of dark matter on galactic scales. However, observations such as the Baryonic Tully-Fisher Relation and the Radial Acceleration Relation, suggest that the observed dynamics in galaxies are strongly correlated with the distribution of baryonic matter. Because they are challenging to explain in the...
Dark matter (DM) substructure is expected to exist over a large range of scales in our Galaxy. Its properties, such as its spatial distribution and abundance at different mass scales, can strongly correlate with the underlying particle physics properties of dark matter. Inferring DM substructure properties can thus hold the key to pinning down the particle nature of DM. In this talk, I will...
Motivated by the absence of new physics signals at LHC and dark matter direct detections, we study new approaches to explore the dark matter and baryogenesis by SKA-like and LISA-like experiments.
We explore the Elastically Decoupling Relic (ELDER) scenario in a general context where $3 \rightarrow 2$ annihilations play an important role in determining the late-time abundance of dark matter (DM), whether the dark sector coupling is strong or weak (the Not-Forbidden Dark Matter, or NFDM, scenario). In the conventional weakly-interacting massive particle (WIMP) paradigm the thermal relic...
We discuss the visibility of gamma lines from dark matter annihilation. We point out a class of theories for dark matter which predict the existence of gamma lines with striking features. In these theories, the final state radiation processes are highly suppressed and one could distinguish easily the gamma lines from the continuum spectrum. We discuss the main experimental bounds and show that...
I will discuss a few questions connecting dark matter and primordial black holes: are they THE dark matter? If so, how can we tell? Did LIGO detect primordial black holes? Do light black holes stop evaporating around the Planck scale? If so, are they detectable? Did primordial black holes generate the dark matter and/or the baryon asymmetry?
What can we learn about the Dark Matter frontier with Gravitational-Wave (GW) observations at LIGO and future detectors?
We first introduce a new GW observable — GW Fringe — that allows LIGO alone to probe compact dark matter such as primordial black holes or dark stars. Furthermore, by augmenting LIGO with mid-frequency detectors, one can also probe various other dark matter kinds via yet...
Many extensions of the Standard Model include the possibility of light new particles, such as axions or dark matter candidates. These scenarios can be probed using the large data sets collected by B-factories, complementing measurements performed at the LHC. The BABAR collaboration has conducted an extensive program to search for axions in B decays, self-interacting or non-miminal dark forces,...
