SIMPle Dark Matter: Self-Interactions and keV Lines

We consider a simple supersymmetric hidden sector: pure SU(N) gauge theory. Dark matter is made up of hidden glueballinos with mass $m_X$ and hidden glueballs with mass near the confinement scale $\Lambda$. For $m_X \sim 1\,\text{TeV}$ and $\Lambda \sim 100\,\text{MeV}$, the glueballinos freeze out with the correct relic density and self-interact through glueball exchange to resolve small-scale structure puzzles. An immediate consequence is that the glueballino spectrum has a hyperfine splitting of order $\Lambda^2 / m_X \sim 10\,\text{keV}$. We show that the radiative decays of the excited state can explain the observed 3.5 keV X-ray line signal from clusters of galaxies, Andromeda, and the Milky Way.Comment: v1: 6 pages, 2 figures; v2: added references, published version; v3: note adde

Bobfergusonite from the Nancy pegmatite, San Luis range, Argentina: Crystal-structure refinement and chemical composition

A second occurrence of bobfergusonite, ideally Na2 Mn2+ 5 Fe3+ Al (PO4 6, has been discovered at the Nancy pegmatite, San Luis Range, Argentina. The Nancy pegmatite is a small, poorly evolved pegmatite of the beryl-columbite-phosphate subtype of rare-element pegmatites. Bobfergusonite from the Nancy pegmatite is monoclinic, a 12.796(3), b 12.465(2), c 11.001(2) Å, 97.39(3)°, V 1740.1(5) Å3, P21/n, Z = 4, has been refined to an R-index of 2.6% for 2959 observed (Fo ≥ 4σF) reflections measured with MoK α X-radiation on a Bruker P4 diffractometer equipped with a CCD detector. The crystal used for the collection of the X-ray intensity data was subsequently analyzed with an electron microprobe. The unit formula derived from the refined site-scattering values and electron-microprobe results is (Na1.10 □0.90) (Na0.90 □0.10) Mn2+ (Mn2+ 0.89 Ca0.11) (Fe2+ 0.91 Fe3+ 0.49 Mn2+ 0.32 Mg0.28) (Fe3+ 0.42 Fe2+ 0.28 Mg0.30) (Al0.94 Fe3+ 0.06) (PO4)6. In bobfergusonite, there are six M sites, each coordinated by six O-atoms in an octahedral arrangement with distances ranging from 1.918 Å at M(6) to 2.237 Å at M(2). There is strong order between the divalent and trivalent cations over the six M sites, and there is also strong order between Al and Fe3+. There are five X sites, X(1)-X(5), each having a wide dispersion of X-O distances. The X(1) site is mainly occupied by Mn2+ and has octahedral coordination. The X(2) and X(3) sites are each [8]-coordinated, the X(4) and X(5) sites are [7]-coordinated, and X(2)-X(5) are all approximately half-occupied by Na. In all of the alluaudite-related structures, the M sites form linear edge-sharing trimers, and the alluaudite, wyllieite and bobfergusonite structures show subtly different patterns of cation order-disorder. Bobfergusonite crystals from both known localities, the Nancy pegmatite (Argentina) and the Cross Lake pegmatite (Manitoba), are considerably disordered.Un deuxième exemple de bobfergusonite, de formule idéale Na2 Mn2+5 Fe3+ Al (PO4)6, a été découvert, celui-ci dans la pegmatite de Nancy, chaîne de San Luis, en Argentine. Cette pegmatite est de taille restreinte, et constitue un exemple peu évolué du sous-type à béryl – columbite – phosphate des pegmatites à éléments rares. La bobfergusonite de cet indice est monoclinique, a 12.796(3), b 12.465(2), c 11.001(2) Å, 97.39(3) , V 1740.1(5) Å3 , P21/n, Z = 4; nous en avons affiné la structure jusqu’à un résidu R de 2.6% pour 2959 réflexions observées (|Fo| ‡ 4F), mesurées avec un diffractomètre Bruker P4 muni d’un détecteur CCD (rayonnement MoK ). Le cristal utilisé a ensuite été analysé avec une microsonde électronique. L’unité formulaire dérivée à partir des valeurs affinées de la dispersion des sites et des résultats des données obtenues à la microsonde électronique est (Na1.10 0.90) (Na0.90 0.10) Mn2+ (Mn2+0.89 Ca0.11) (Fe2+0.91 Fe3+0.49 Mn2+0.32 Mg0.28) (Fe3+0.42 Fe2+0.28 Mg0.30) (Al0.94 Fe3+0.06) (PO4)6. La structure contient six sites M, chacun coordonné par six atomes d’oxygène dans un agencement octaédrique, avec les distances entre 1.918 Å pour M(6) jusqu’à 2.237 Å pour M(2). Il y a une forte mise en ordre entre les cations bivalents et trivalents sur les six sites M, et il y a aussi une forte mise en ordre entre Al et Fe3+. La structure contient cinq sites X, X(1)–X(5), chacun faisant preuve d’une grande dispersion des distances X–O. Le site X(1) est surtout rempli par le Mn2+ et possède une coordinence octaédrique. Les sites X(2) et X(3) ont chacun une coordinence [8], et les sites X(4) et X(5), une coordinence [7]; les sites X(2)– X(5) sont tous environ à moitié remplis par le Na. Dans tous les membres du groupe de l’alluaudite, les sites M forment des groupes trimériques linéaires d’octaèdres à arêtes partagées, et les structures de l’alluaudite, la wyllieïte et la bobfergusonite possèdent des degrés d’ordre et désordre subtilement différents. Les cristaux de bobfergusonite des deux localités, la pegmatite de Nancy, en Argentine, celle de Cross Lake, au Manitoba, sont considérablement désordonnés.Fil: Tait, Kimberly T.. University of Manitoba; CanadáFil: Hawthorne, Frank C.. University of Manitoba; CanadáFil: Cerny, Petr. University of Manitoba; CanadáFil: Galliski, Miguel Angel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentin

Self-Interacting Dark Matter from a Non-Abelian Hidden Sector

There is strong evidence in favor of the idea that dark matter is self interacting, with the cross section-to-mass ratio σ/m∼1  cm^2/g∼1  barn/GeV. We show that viable models of dark matter with this large cross section are straightforwardly realized with non-Abelian hidden sectors. In the simplest of such models, the hidden sector is a pure gauge theory, and the dark matter is composed of hidden glueballs with a mass around 100 MeV. Alternatively, the hidden sector may be a supersymmetric pure gauge theory with a ∼10  TeV gluino thermal relic. In this case, the dark matter is largely composed of glueballinos that strongly self interact through the exchange of light glueballs. We present a unified framework that realizes both of these possibilities in anomaly-mediated supersymmetry breaking, where, depending on a few model parameters, the dark matter may be composed of hidden glueballinos, hidden glueballs, or a mixture of the two. These models provide simple examples of multicomponent dark matter, have interesting implications for particle physics and cosmology, and include cases where a subdominant component of dark matter may be extremely strongly self interacting, with interesting astrophysical consequences

Strongly interacting dark matter: Self-interactions and keV lines

We consider a simple supersymmetric hidden sector: pure SU(N) gauge theory. Dark matter is made up of hidden glueballinos with mass m_X and hidden glueballs with mass near the confinement scale Λ. For m_X ∼ 1 TeV and Λ ∼ 100 MeV, the glueballinos freeze out with the correct relic density and selfinteract through glueball exchange to resolve small-scale structure puzzles. An immediate consequence is that the glueballino spectrum has a hyperfine splitting of order Λ^2 = m_X ∼ 10 keV. We show that the radiative decays of the excited state can explain the observed 3.5 keV x-ray line signal from clusters of galaxies, Andromeda, and the Milky Way

Modelling phosphorus (P), sulfur (S) and iron (Fe) interactions for dynamic simulations of anaerobic digestion processes

This paper proposes a series of extensions to functionally upgrade the IWA Anaerobic Digestion Model No. 1 (ADM1) to allow for plant-wide phosphorus (P) simulation. The close interplay between the P, sulfur (S) and iron (Fe) cycles requires a substantial (and unavoidable) increase in model complexity due to the involved three-phase physico-chemical and biological transformations. The ADM1 version, implemented in the plant-wide context provided by the Benchmark Simulation Model No. 2 (BSM2), is used as the basic platform (A0). Three different model extensions (A1, A2, A3) are implemented, simulated and evaluated. The first extension (A1) considers P transformations by accounting for the kinetic decay of polyphosphates (XPP) and potential uptake of volatile fatty acids (VFA) to produce polyhydroxyalkanoates (XPHA) by phosphorus accumulating organisms (XPAO). Two variant extensions (A2,1/A2,2) describe biological production of sulfides (SIS) by means of sulfate reducing bacteria (XSRB) utilising hydrogen only (autolithotrophically) or hydrogen plus organic acids (heterorganotrophically) as electron sources, respectively. These two approaches also consider a potential hydrogen sulfide (ZH2SÞ inhibition effect and stripping to the gas phase (GH2S). The third extension (A3) accounts for chemical iron (III) (SFe3þ ) reduction to iron (II) (SFe2þ ) using hydrogen (SH2 ) and sulfides (SIS) as electron donors. A set of pre/post interfaces between the Activated Sludge Model No. 2d (ASM2d) and ADM1 are furthermore proposed in order to allow for plant-wide (model-based) analysis and study of the interactions between the water and sludge lines. Simulation (A1 e A3) results show that the ratio between soluble/particulate P compounds strongly depends on the pH and cationic load, which determines the capacity to form (or not) precipitation products. Implementations A1 and A2,1/A2,2 lead to a reduction in the predicted methane/biogas production (and potential energy recovery) compared to reference ADM1 predictions (A0). This reduction is attributed to two factors: (1) loss of electron equivalents due to sulfate ðSSO4 Þ reduction by XSRB and storage of XPHA by XPAO; and, (2) decrease of acetoclastic and hydrogenotrophic methanogenesis due to ZH2S inhibition. Model A3 shows the potential for iron to remove free SIS (and consequently inhibition) and instead promote iron sulfide (XFeS) precipitation. It also educes the quantities of struvite (XMgNH4PO4) and calcium hosphate (XCa3ðPO4Þ2) that are formed due to its higher affinity for phosphate anions. This study provides a detailed analysis of the different model assumptions, the effect that operational/design conditions have on the model predictions and the practical implications of the proposed model extensions in view of plant-wide modelling/development of resource recovery strategies

Kinetics and Phenotype of Vaccine-Induced CD8+ T-Cell Responses to Toxoplasma gondii

Multiple studies have established that the ability of CD8+ T cells to act as cytolytic effectors and produce gamma interferon is important in mediating resistance to the intracellular parasite Toxoplasma gondii. To better understand the generation of the antigen-specific CD8+ T-cell responses induced by T. gondii, mice were immunized with replication-deficient parasites that express the model antigen ovalbumin (OVA). Class I tetramers specific for SIINFEKL were used to track the OVA-specific endogenous CD8+ T cells. The peak CD8+ T-cell response was found at day 10 postimmunization, after which the frequency and numbers of antigen-specific cells declined. Unexpectedly, replication-deficient parasites were found to induce antigen-specific cells with faster kinetics than replicating parasites. The generation of optimal numbers of antigen-specific CD8+ effector T cells was found to require CD4+ T-cell help. At 7 days following immunization, antigen-specific cells were found to be CD62Llow, KLRG1+, and CD127low, and they maintained this phenotype for more than 70 days. Antigen-specific CD8+ effector T cells in immunized mice exhibited potent perforin-dependent OVA-specific cytolytic activity in vivo. Perforin-dependent cytolysis appeared to be the major cytolytic mechanism; however, a perforin-independent pathway that was not mediated via Fas-FasL was also detected. This study provides further insight into vaccine-induced cytotoxic T-lymphocyte responses that correlate with protective immunity to T. gondii and identifies a critical role for CD4+ T cells in the generation of protective CD8+ T-cell responses

Preservation of primordial signatures of water in highly-shocked ancient lunar rocks

Spurred by the discovery of water in lunar volcanic glasses about a decade ago, the accessory mineral apatite became the primary target to investigate the abundance and source of lunar water. This is due to its ability to contain significant amounts of OH in its structure, along with the widespread presence of apatite in lunar rocks. There is a general understanding that crustal cumulate rocks of the lunar magnesian (Mg) suite are better candidates for recording the original isotopic compositions of volatile elements in their parental melts compared to eruptive rocks, such as mare basalts. Consequently, water-bearing minerals in Mg-suite rocks are thought to be ideal candidates for discerning the primary hydrogen isotopic composition of water in the lunar interior. Mg-suite rocks and most other Apollo samples that were collected at the lunar surface display variable degrees of shock-deformation. In this study, we have investigated seven Apollo 17 Mg-suite samples that include troctolite, gabbro and norite lithologies, in order to understand if shock processes affected the water abundances and/or H isotopic composition of apatite. The measured water contents in apatite grains range from 31 to 964 ppm, with associated δD values varying between −535 ±134‰ and +147 ±194‰(2σ). Considering the full dataset, there appears to be no correlation between H2O and δD of apatite and the level of shock each apatite grain has experienced. However, the lowest δD was recorded by individual, water-poor (∼100 ppm H2O), regardless of the complexity of the shock-induced nanostructures, there appears to be no evidence of water-loss or alteration in their δD. The weighted average δD value of 24 such water-rich apatites is −192 ±71‰, and, of all 36 analyzed spots is −209 ±47‰, indistinguishable from that of other KREEPy lunar lithologies or the Earth’s deep mantle. Despite experiencing variable degrees of shock-deformation at a later stage in lunar history, water-rich apatite in some of the earliest-formed lunar crustal material appears to retain the original isotopic signature of H in the Moon