Death by Dark Matter

Physics Letters B

Macroscopic dark matter (macros) refers to a class of dark matter candidates that scatter elastically off of ordinary matter with a large geometric crosssection. A wide range of macro masses M X and cross-sections σ X remain unprobed. We show that over a wide region within the unexplored parameter space, collisions of a macro with a human body would result in serious injury or death. We use the absence of such unexplained impacts with a wellmonitored subset of the human population to exclude a region bounded by σ X > 10 −8 − 10 −7 cm 2 and M X < 50 kg. Our results open a new window on dark matter: the human body as a dark matter detector

Eprint Arxiv 1410 2236, 2014

Dark matter is a vital component of the current best model of our universe, $\Lambda$CDM. There are leading candidates for what the dark matter could be (e.g. weakly-interacting massive particles, or axions), but no compelling observational or experimental evidence exists to support these particular candidates, nor any beyond-the-Standard-Model physics that might produce such candidates. This suggests that other dark matter candidates, including ones that might arise in the Standard Model, should receive increased attention. Here we consider a general class of dark matter candidates with characteristic masses and interaction cross-sections characterized in units of grams and cm$^2$, respectively -- we therefore dub these macroscopic objects as Macros. Such dark matter candidates could potentially be assembled out of Standard Model particles (quarks and leptons) in the early universe. A combination of Earth-based, astrophysical, and cosmological observations constrain a portion of the Macro parameter space. A large region of parameter space remains, most notably for nuclear-dense objects with masses in the range $55 - 10^{17}$ g and $2\times10^{20} - 4\times10^{24}$ g, although the lower mass window is closed for Macros that destabilize ordinary matter.

Dark matter is a vital component of the current best model of our universe, CDM.There are leading candidates for what the dark matter could be (e.g. weakly-interacting massive particles, or axions), but no compelling observational or exper-imental evidence exists to support these particular candidates, nor any beyond-the-Standard-Model physics that might produce such candidates. This suggests that other dark matter candidates, including ones that might arise in the Standard Model, should receive increased attention. Here we consider a general class of dark matter candi-dates with characteristic masses and interaction cross-sections characterized in units of grams and cm2, respectively. we therefore dub these macroscopic objects as Macros. Such dark matter candidates could potentially be assembled out of Standard Model particles (quarks and leptons) in the early universe. A combination of Earth-based, astrophysical, and cosmological observations constrain a portion of the Macro param-eter space. A large region of parameter space remains, most notably for nuclear-dense objects with masses in the range from 2 × 10 20 to 4 × 10 24 , although the lower mass window is closed for Macros that destabilize ordinary matter.

Current bounds from several astrophysical and laboratory observations are pointing towards new paradigms for dark matter properties. Through a complete analysis of this landscape and a comparison between experimental data, guided by a criterion for simplicity, one can try to solve the puzzling question of what dark matter really is and behaves. In this work I try to highlight the hints that allow us to establish concrete sentences about dark matter, for what concerns annihilation cross section, interaction cross sections, mass and spin. The emerging scenario shows that this particle is characterized by a fundamental collisionless behavior, which defines it even better that the inability to interact with light, and it must be very heavy — lying in the 1–10 TeV mass range — in order to satisfy all the constraints.

Physical Review D

A number of dark matter candidates have been discussed that are macroscopic, of approximately nuclear density, and scatter ordinary matter essentially elastically with approximately their geometric cross-section. A wide range of mass and geometric cross-section is still unprobed for these "macros." Macros passing through rock would melt the material in cylinders surrounding their long nearly straight trajectories. Once cooled, the resolidified rock would be easily distinguishable from its surroundings. We discuss how, by visually examining ordinary slabs of rock such as are widely available commercially for kitchen countertops, one could probe an interesting segment of the open macro parameter space.

One of the biggest scientific mysteries of our time resides in the identification of the particles that constitute a large fraction of the mass of our Universe, generically known as dark matter. We review the observations and the experimental data that imply the existence of dark matter. We briefly discuss the properties of the two best dark-matter candidate particles and the experimental techniques presently used to try to discover them. Finally, we mention a proposed project that has recently emerged within the Mexican community to look for dark matter.

Brazilian Journal of Physics, 2013

The dark matter story passed through several stages on its way from a minor observational puzzle to a major challenge for theory of elementary particles. I begin the review with the description of the discovery of the mass paradox in our Galaxy and in clusters of galaxies. First hints of the problem appeared already in 1930s and later more observational arguments were brought up, but the issue of the mass

arXiv: Astrophysics, 1995

We review some recent determinations of the amount of dark matter on galactic and larger scales, with special attention to the dark matter in the Milky Way. We then briefly review the motivation for and basic physics of several dark matter candidates, and then go into more depth for two candidates, the neutralino from supersymmetry, and the baryonic Macho candidate. We give some motivation for supersymmetry and review neutralino detection strategies. For Machos we give a description of the discovery of Machos via gravitational microlensing and the interpretation of the results with respect to the dark matter problem.

Les Houches, 2007

This is the mini-review on Dark Matter in the 2012 edition of the Particle Data Group&#39;s Review of Particle Properties. After briefly summarizing the arguments in favor of the existence of Dark Matter, we list possible candidates, ranging in mass from a fraction of an eV (e.g., axions) to many solar masses (e.g., primordial black holes), and discuss ways to detect them. The main emphasis is on Weakly Interacting Massive Particles (WIMPs). A large international effort is being made to detect them directly, or else to detect their annihilation products. We explain why we consider all claims to have established a positive signal for WIMPs in either direct or indirect detection to be premature. We also introduce the concept of a {\it WIMP safe} minimal mass; below this mass, the interpretation of a given direct search experiment depends strongly on the tail of the WIMP velocity distribution and/or on the experimental energy resolution.