Resonance enhancement of dark matter interactions: the case for early kinetic decoupling and velocity dependent resonance width

Motivated by the possibility of enhancing dark matter (DM) self-interaction cross-section $\sigma_{\rm self}$, 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 DM and an interesting interplay in the evolution of DM density and temperature that can be described by a set of coupled Boltzmann equations. The standard Breit-Wigner parametrization of a resonance propagator is also corrected by including momentum dependence of the resonance width. It has been shown that this effects may change predictions of DM relic density by more than order of magnitude in some regions of the parameter space. Model independent discussion is illustrated within a theory of Abelian vector dark matter. The model assumes extra $U(1)$ symmetry group factor and an additional complex Higgs field needed to generate a mass for the dark vector boson, which provides an extra neutral Higgs boson $h_2$. We discuss the resonance amplification of $\sigma_{\rm self}$. It turns out that if DM abundance is properly reproduced, the Fermi-LAT data favor heavy DM and constraint the enhancement of $\sigma_{\rm self}$ to the range, which cannot provide a solution to the small-scale structure problems.}Comment: 17 pages, 5 figures, v2: minor changes in text, BBN and CMB constraints adde

Gauge-Independent Approach to Resonant Dark Matter Annihilation

In spontaneously broken gauge theories, transition amplitudes describing dark-matter (DM) annihilation processes through a resonance may become highly inaccurate close to a production threshold, if a Breit-Wigner (BW) ansatz with a constant width is used. To partially overcome this problem, the BW propagator needs to be modified by including a momentum dependent decay width. However, such an approach to resonant transition amplitudes generically suffers from gauge artefacts that may also give rise to a bad or ambiguous high-energy behaviour for such amplitudes. We address the two problems of gauge dependence and high-energy unitarity within a gauge-independent framework of resummation implemented by the so-called Pinch Technique. We study DM annihilation via scalar resonances in a gauged U(1)$_X$ complex-scalar extension of the Standard Model that features a massive stable gauge field which can play the role of the DM. We find that the predictions for the DM abundance may vary significantly from previous studies based on the naive BW ansatz and propose an alternative simple approximation which leads to the correct DM phenomenology. In particular, our results do not depend on the gauge-fixing parameter and are consistent with considerations from high-energy unitarity.Comment: 29 pages, 9 figures, v2: minor typos corrected, matches published versio

Strongly self-interacting vector dark matter via freeze-in

We study a vector dark matter (VDM) model in which the dark sector couples to the Standard Model sector via a Higgs portal. If the portal coupling is small enough the VDM can be produced via the freeze-in mechanism. It turns out that the electroweak phase transition have a substantial impact on the prediction of the VDM relic density. We further assume that the dark Higgs boson which gives the VDM mass is so light that it can induce strong VDM self-interactions and solve the small-scale structure problems of the Universe. As illustrated by the latest LUX data, the extreme smallness of the Higgs portal coupling required by the freeze-in mechanism implies that the dark matter direct detection bounds are easily satisfied. However, the model is well constrained by the indirect detections of VDM from BBN, CMB, AMS-02, and diffuse $\gamma$/X-rays. Consequently, only when the dark Higgs boson mass is at most of ${\cal O}({\rm keV})$ does there exist a parameter region which leads to a right amount of VDM relic abundance and an appropriate VDM self-scattering while satisfying all other constraints simultaneously.Comment: 29 pages, 8 figure

Multi-Component Dark Matter: the vector and fermion case

Multi-component dark matter scenarios constitute natural extensions of standard single-component setups and offer attractive new dynamics that could be adopted to solve various puzzles of dark matter. In this work we present and illustrate properties of a minimal UV-complete vector-fermion dark matter model where two or three dark sector particles are stable. The model we consider is an extension of the Standard Model (SM) by spontaneously broken extra $U(1)_X$ gauge symmetry and a Dirac fermion. All terms in the Lagrangian which are consistent with the assumed symmetry are present, so the model is renormalizable and consistent. To generate mass for the dark-vector $X_\mu$ the Higgs mechanism with a complex singlet $S$ is employed in the dark sector. Dark matter candidates are the massive vector boson $X_\mu$ and two Majorana fermions $\psi_\pm$. All the dark sector fields are singlets under the SM gauge group. The set of three coupled Boltzmann equations has been solved numerically and discussed. We have performed scans over the parameter space of the model implementing the total relic abundance and direct detection constraints. The dynamics of the vector-fermion dark matter model is very rich and various interesting phenomena appear, in particular, when the standard annihilations of a given dark matter are suppressed then the semi-annihilations, conversions and decays within the dark sector are crucial for the evolution of relic abundance and its present value. Possibility of enhanced self-interaction has been also discussed.Comment: v2: 25 pages + appendices, 12 captioned figures, a section on multi-component self-interacting dark matter is added, matches the journal accepted versio

Classification of effective operators for interactions between the Standard Model and dark matter

We construct a basis for effective operators responsible for interactions between the Standard Model and a dark sector composed of particles with spin less or equal to 1. Redundant operators are eliminated using dim-4 equations of motion. We consider simple scenarios where the dark matter components are stabilized against decay by Z2 symmetries. We determine operators which are loop-generated within an underlying theory and those that are potentially tree-level generated

Pamięć zbiorowa o Auschwitz i stosunek do Żydów w trzech wspólnotach pamięci katolików w Polsce : wyniki badania jakościowego

W artykule omówiono wyniki przeprowadzonych w 2010 roku zogniskowanych wywiadów grupowych z przedstawicielami trzech środowisk katolickich stanowiących różne "wspólnoty pamięci": Klubu Inteligencji Katolickiej w Krakowie - "wspólnoty pamięci heroiczno-martyrologicznej", Rodziny Radia Maryja z Rzeszowa - "wspólnoty pamięci zamkniętej", i intelektualistów związanych z kurią arcybiskupią w Lublinie - "wspólnoty pamięci otwartej". Typy wspólnot pamięci zostają określone na podstawie stosunku badanych do wydarzeń II wojny światowej. Każda z grup była pytana o percepcję Auschwitz oraz stosunek do opinii wyrażających różne rodzaje antysemityzmu: polityczny, gospodarczy, dotyczący mediów, międzynarodowy, religijny i postholokaustowy. Analiza pokazuje, że "wspólnota pamięci heroiczno-martyrologicznej" nie postrzega Auschwitz w kategoriach polskich, a wielonarodowościowych i ogólnoludzkich, podobnie jak "wspólnota pamięci zamkniętej". Obydwie są świadome zagłady Żydów w obozie. Pierwsza wspólnota przejawia ukryty antysemityzm nowoczesny, lecz zdecydowanie odrzuca antysemityzm religijny i postholokaustowy. Druga przejawia otwarty i silny antysemityzm nowoczesny, lecz jest podzielona w kwestii antysemityzmu religijnego. Wspólnota otwarta postrzega Auschwitz w kategoriach ogólnoludzkich, międzynarodowych i żydowskich oraz kategorycznie odrzuca wszelki antysemityzm

On the recognition of the game type based on physiological signals and eye tracking

Automated interpretation of signals yields many impressive applications from the area of affective computing and human activity recognition (HAR). In this paper we ask the question about possibility of cognitive activity recognition on the base of particular set of signals. We use recognition of the game played by the participant as a playground for exploration of the problem. We build classifier of three different games (Space Invaders, Tetris, Tower Defence) and inter-game pause. We validate classifier in the player-independent and player-dependent scenario. We discuss the improvement in the player-dependent scenario in the context of biometric person recognition. On the base of the results obtained in game classification, we consider potential applications in smart surveillance and quantified self.Comment: 5 pages, 3 figures, extended version of ESM pape