Constraints on Dark Matter from the Moon

New and complimentary constraints are placed on the spin-independent interactions of dark matter with baryonic matter. Similar to the Earth and other planets, the Moon does not have any major internal heat source. We derive constraints by comparing the rate of energy deposit by dark matter annihilations in the Moon to 12 mW/m$^2$ as measured by the Apollo mission. For light dark matter of mass $\mathcal{O}(10)$ GeV, we also examine the possibility of dark matter annihilations in the Moon limb. In this case, we place constraints by comparing the photon flux from such annihilations to that of the Fermi-LAT measurement of $10^{-4}$ MeV/cm$^2$s. This analysis excludes spin independent cross section $\gtrsim 10^{-37}$ $\rm{cm}^2$ for dark matter mass between 30 and 50 GeV.Comment: 9 pages; v2: Improved moon models, updated references. Matches published versio

Phenomenology of Dark Matter Annihilations in the Sun

The annihilation of dark matter (DM) particles accumulated in the Sun could produce a flux of neutrinos, which is potentially detectable with neutrino detectors/telescopes and the DM elastic scattering cross section can be constrained. Although the process of DM capture in astrophysical objects like the Sun is commonly assumed to be due to interactions only with nucleons, there are scenarios in which tree-level DM couplings to quarks are absent, and even if loop-induced interactions with nucleons are allowed, scatterings off electrons could be the dominant capture mechanism. We consider this possibility and study in detail all the ingredients necessary to compute the neutrino production rates from DM annihilations in the Sun (capture, annihilation and evaporation rates) for velocity-independent and isotropic, velocity-dependent and isotropic and momentum-dependent scattering cross sections for DM interactions with electrons and compare them with the results obtained for the case of interactions with nucleons. Moreover, we improve the usual calculations in a number of ways and provide analytical expressions. Interestingly, we find that the evaporation mass in the case of interactions with electrons could be below the GeV range, depending on the high-velocity tail of the DM distribution in the Sun, which would open a new mass window for searching for this type of scenarios.Die Annihilation von Dunkler Materie (DM), die sich in der Sonne angesammelt hat, könnte einen Fluss von Neutrinos erzeugen, der potentiell mit Neutrino-Detektoren / Teleskopen detektierbar ist und der DM-Streuquerschnitt eingeschränkt werden kann. Obwohl angenommen wird, dass der Prozess der DM-Erfassung in astrophysikalischen Objekten wie der Sonne nur auf Wechselwirkungen mit Nukleonen zurückzuführen ist, gibt es Szenarien, in denen DM-Kopplungen zwischen Bäumen auf Quarks fehlen und auch wenn Schleifen-induzierte Wechselwirkungen mit Nukleonen zulässig sind Streuungen von Elektronen könnten der dominierende Erfassungsmechanismus sein. Wir betrachten diese Möglichkeit und untersuchen detailliert alle notwendigen Bestandteile, um die Neutrino-Produktionsraten aus den DM-Annihilationen in der Sonne (Einfang-, Annihilations- und Verdampfungsraten) für geschwindigkeitsunabhängiges und isotropes, geschwindigkeitsabhängiges und isotropes sowie impulsabhängiges Streukreuz zu berechnen Abschnitte für DM-Wechselwirkungen mit Elektronen und vergleichen sie mit den Ergebnissen für den Fall der Wechselwirkungen mit Nukleonen. Darüber hinaus verbessern wir die üblichen Berechnungen auf verschiedene Arten und liefern analytische Ausdrücke. Interessanterweise finden wir, dass die Verdampfungsmasse im Falle von Wechselwirkungen mit Elektronen unterhalb des GeV-Bereichs liegen könnte, abhängig von dem Hochgeschwindigkeits-Schwanz der DM-Verteilung in der Sonne, was ein neues Massenfenster für die Suche nach dieser Art von Atomen eröffnen würde Szenarien

Dark matter interactions with muons in neutron stars

Neutron stars contain a significant number of stable muons due to the large chemical potential and degenerate electrons. This makes them the unique vessel to capture muonphilic dark matter, which does not interact with other astrophysical objects, including Earth and its direct-detection experiments. The infalling dark matter can heat up the neutron star both kinetically and via annihilations, which is potentially observable with future infrared telescopes. New physics models for muonphilic dark matter can easily be motivated by, and connected to, existing anomalies in the muon sector, e.g., the anomalous magnetic moment or LHCb's recent hints for lepton-flavor non-universality in $B\to K\mu^+\mu^-$ decays. We study the implications for a model with dark matter charged under a local $U(1)_{L_\mu-L_\tau}$.Comment: 7 pages; v2: added references and improved heating from annihilations; v3: matches PRD versio

Flavored Co-annihilations

Neutralino dark matter in supersymmetric models is revisited in the presence of flavor violation in the soft supersymmetry breaking sector. We focus on flavor violation in the sleptonic sector and study the implications for the co-annihilation regions. Flavor violation is introduced by a single $\tilde{\mu}_R-\tilde{\tau}_R$ insertion in the slepton mass matrix. Limits on this insertion from BR($\tau \to \mu + \gamma$) are weak in some regions of the parameter space where cancellations happen within the amplitudes. We look for overlaps in parameter space where both the co-annihilation condition as well as the cancellations within the amplitudes occur. In mSUGRA, such overlap regions are not existent, whereas they are present in models with non-universal Higgs boundary conditions (NUHM). The effect of flavor violation is two fold: (a) it shifts the co-annihilation regions towards lighter neutralino masses (b) the co-annihilation cross sections would be modified with the inclusion of flavor violating diagrams which can contribute significantly. Even if flavor violation is within the presently allowed limits, this is sufficient to modify the thermally averaged cross-sections by about (10-15)% in mSUGRA and (20-30)% in NUHM, depending on the parameter space. In the overlap regions, the flavor violating cross sections become comparable and in some cases even dominant to the flavor conserving ones. A comparative study of the channels is presented for mSUGRA and NUHM cases.Comment: 38 pages, 28 figures. Significantly expanded and improved version with a new section on channels and new appendices on mSUGRA and cross-sections, version accepted for publication in JHE

Observing the thermalization of dark matter in neutron stars

A promising probe to unmask particle dark matter is to observe its effect on neutron stars, the prospects of which depend critically on whether captured dark matter thermalizes in a timely manner with the stellar core via repeated scattering with the Fermi-degenerate medium. In this work we estimate the timescales for thermalization for multiple scenarios. These include: (a) spin-0 and spin-$\frac{1}{2}$ dark matter, (b) scattering on non-relativistic neutron and relativistic electron targets accounting for the respective kinematics, (c) interactions via a range of Lorentz-invariant structures, (d) mediators both heavy and light in comparison to the typical transfer momenta in the problem. We discuss the analytic behavior of the thermalization time as a function of the dark matter and mediator masses, and the stellar temperature. Finally, we identify parametric ranges where both stellar capture is efficient and thermalization occurs within the age of the universe. For dark matter that can annihilate in the core, these regions indicate parametric ranges that can be probed by upcoming infrared telescopes observing cold neutron stars.Comment: 12 pages revtex4, 7 figures, 2 tables; v2: references added, minor typos fixe

Could compact stars in globular clusters constrain dark matter?

The dark matter content of globular clusters, highly compact gravity-bound stellar systems, is unknown. It is also generally unknow*able*, due to their mass-to-light ratios typically ranging between 1$-$3 in solar units, accommodating a dynamical mass of dark matter at best comparable to the stellar mass. That said, recent claims in the literature assume densities of dark matter around 1000 GeV/cm$^3$ to set constraints on its capture and annihilation in white dwarfs residing in the globular cluster M4, and to study a number of other effects of dark matter on compact stars. Motivated by these studies, we use measurements of stellar kinematics and luminosities in M4 to look for a dark matter component via a spherical Jeans analysis; we find no evidence for it, and set the first empirical limits on M4's dark matter distribution. Our density upper limits, a few $\times \ 10^4$ GeV/cm$^3$ at 1 parsec from the center of M4, do not negate the claims (nor confirm them), but do preclude the use of M4 for setting limits on non-annihilating dark matter kinetically heating white dwarfs, which require at least $10^5$ GeV/cm$^3$ densities. The non-robust nature of globular clusters as dynamical systems, combined with evidence showing that they may originate from molecular gas clouds in the absence of dark matter, make them unsuitable as laboratories to unveil dark matter's microscopic nature in current or planned observations.Comment: 10 pages revtex4 + references, 3 figures, 1 tabl

SuSeFLAV: A program for calculating supersymmetric spectra and lepton flavor violation

We introduce the program SuSeFLAV for computing supersymmetric mass spectra with flavor violation in various supersymmetric breaking scenarios with/without seesaw mechanism. A short user guide summarizing the compilation, executables and the input files is provided.Comment: 3 pages, latex, pramana style, proceedings for Lepton Photon 201

Systematic uncertainties from halo asphericity in dark matter searches

Although commonly assumed to be spherical, dark matter halos are predicted to be non-spherical by N-body simulations and their asphericity has a potential impact on the systematic uncertainties in dark matter searches. The evaluation of these uncertainties is the main aim of this work, where we study the impact of aspherical dark matter density distributions in Milky-Way-like halos on direct and indirect searches. Using data from the large N-body cosmological simulation Bolshoi, we perform a statistical analysis and quantify the systematic uncertainties on the determination of local dark matter density and the so-called $J$ factors for dark matter annihilations and decays from the galactic center. We find that, due to our ignorance about the extent of the non-sphericity of the Milky Way dark matter halo, systematic uncertainties can be as large as 35%, within the 95% most probable region, for a spherically averaged value for the local density of 0.3-0.4 GeV/cm$^3$. Similarly, systematic uncertainties on the $J$ factors evaluated around the galactic center can be as large as 10% and 15%, within the 95% most probable region, for dark matter annihilations and decays, respectively.Comment: 29 pages, 6 artistic figures, version accepted for publication in JCA

SUSEFLAV: program for supersymmetric mass spectra with seesaw mechanism and rare lepton flavor violating decays

Accurate supersymmetric spectra are required to confront data from direct and indirect searches of supersymmetry. \SUSEFLAV is a numerical tool which is capable of computing supersymmetric spectra accurately for various supersymmetric breaking scenarios applicable even in the presence of flavor violation. The program solves MSSM RGEs with complete $3\times3$ flavor mixing at 2-loop level and one loop finite threshold corrections to all MSSM parameters by incorporating radiative electroweak symmetry breaking conditions. The program also incorporates the Type-I seesaw mechanism with three massive right handed neutrinos at user defined mass scales and mixing. It also computes branching ratios of flavor violating processes such as $l_j \rightarrow l_i\gamma$, $l_j \rightarrow 3 ~l_i$, $b \rightarrow s\gamma$ and supersymmetric contributions to flavor conserving quantities such as $(g_{\mu}-2)$. A large choice of executables suitable for various operations of the program are provided.Comment: Added comments about light higgs mass at 125 GeV and a few references. Published in CPC versio