scholarly journals Radiative bound-state-formation cross-sections for dark matter interacting via a Yukawa potential

2017 ◽  
Vol 2017 (4) ◽  
Author(s):  
Kalliopi Petraki ◽  
Marieke Postma ◽  
Jordy de Vries
Keyword(s):  
Dark Matter ◽  
State Formation ◽  
Cross Sections ◽  
Yukawa Potential ◽  
Bound State

scholarly journals Rapid Bound State Formation of Dark Matter in the Early Universe

2020 ◽  
Vol 124 (16) ◽  
Author(s):  
Tobias Binder ◽  
Kyohei Mukaida ◽  
Kalliopi Petraki
Keyword(s):  
Dark Matter ◽  
Early Universe ◽  
State Formation ◽  
Bound State

scholarly journals Indirect searches for dark matter bound state formation and level transitions

2020 ◽  
Vol 9 (5) ◽  
Author(s):  
Iason Baldes ◽  
Francesca Calore ◽  
Kalliopi Petraki ◽  
Vincent Poireau ◽  
Nicholas L. Rodd
Keyword(s):  
Dark Matter ◽  
State Formation ◽  
Bound States ◽  
Bound State ◽  
Photon Mass ◽  
Dark Photon ◽  
Dissipation Of Energy ◽  
Light Force

Indirect searches for dark matter (DM) have conventionally been applied to the products of DM annihilation or decay. If DM couples to light force carriers, however, it can be captured into bound states via dissipation of energy that may yield detectable signals. We extend the indirect searches to DM bound state formation and transitions between bound levels, and constrain the emission of unstable dark photons. Our results significantly refine the predicted signal flux that could be observed in experiments. As a concrete example, we use Fermi-LAT dwarf spheroidal observations to obtain constraints in terms of the dark photon mass and energy which we use to search for the formation of stable or unstable bound states.

scholarly journals Constraining Velocity-dependent Self-Interacting Dark Matter with the Milky Way’s dwarf spheroidal galaxies

2021 ◽  
Author(s):  
Camila A Correa
Keyword(s):  
Dark Matter ◽  
Cross Section ◽  
Cross Sections ◽  
Yukawa Potential ◽  
Analytical Form ◽  
Orbital Evolution ◽  
Particle Model ◽  
Velocity Correlation ◽  
Dwarf Spheroidal Galaxies ◽  
Spheroidal Galaxies

Abstract The observed anti-correlation between the central dark matter (DM) densities of the bright Milky Way (MW) dwarf spheroidal galaxies (dSphs) and their orbital pericenter distances poses a potential signature of self-interacting dark matter (SIDM). In this work we investigate this possibility by analysing the range of SIDM scattering cross section per unit mass, σ/mχ, able to explain such anti-correlation. We simulate the orbital evolution of dSphs subhaloes around the MW assuming an analytical form for the gravitational potential, adopting the proper motions from the Gaia mission and including a consistent characterization of gravitational tidal stripping. The evolution of subhalo density profiles is modelled using the gravothermal fluid formalism, where DM particle collisions induce thermal conduction that depends on σ/mχ. We find that models of dSphs, such as Carina and Fornax, reproduce the observed central DM densities with fixed σ/mχ ranging between 30 and 50 cm2g−1, whereas other dSphs prefer larger values ranging between 70 and 100 cm2g−1. These cross sections correlate with the average collision velocity of DM particles within each subhalo’s core, so that systems modelled with large cross sections have lower collision velocities. We fit the cross section-velocity correlation with a SIDM particle model, where a DM particle of mass mχ = 53.93 ± 9.81 GeV interacts under the exchange of a light mediator of mass mφ = 6.6 ± 0.43 MeV, with the self-interactions being described by a Yukawa potential. The outcome is a cross section-velocity relation that explains the diverse DM profiles of MW dSph satellites and is consistent with observational constraints on larger scales.

scholarly journals Dark matter bound state formation in fermionic Z2 DM model with light dark photon and dark Higgs boson

2020 ◽  
Vol 2020 (10) ◽  
Author(s):  
Pyungwon Ko ◽  
Toshinori Matsui ◽  
Yi-Lei Tang
Keyword(s):  
Dark Matter ◽  
Higgs Boson ◽  
Gauge Symmetry ◽  
State Formation ◽  
Vector Boson ◽  
Goldstone Boson ◽  
Bound State ◽  
Dark Photon ◽  
Potential Matrix ◽  
Relic Abundance

Abstract If fermionic dark matter (DM) is stabilized by dark U(1) gauge symmetry that is spontaneously broken into its subgroup Z2, the particle contents of the model becomes very rich: DM and excited DM, both of them are Majorana fermions, as well as two dark force mediators, dark photon and dark Higgs boson are naturally present due to the underlying dark gauge symmetry. In this paper, we study the DM bound state formation processes within this scenario, assuming both dark photon and dark Higgs are light mediators and including the effects of excited DM. The Goldstone boson contributions to the potential matrix in the Schrödinger equations are found to be important. The emissions of a longitudinal vector boson (or somehow equivalently a Goldstone boson) during the DM bound state formations are crucial to induce a significant reannihilation process, reducing the dark matter relic abundance. Most of the stringent constraints for this kind of dark matter considered in the literature are simply evaded.

scholarly journals Bound-state formation for thermal relic dark matter and unitarity

2014 ◽  
Vol 2014 (12) ◽  
pp. 033-033 ◽  
Author(s):  
Benedict von Harling ◽  
Kalliopi Petraki
Keyword(s):  
Dark Matter ◽  
State Formation ◽  
Bound State

scholarly journals Dark matter bound-state formation at higher order: a non-equilibrium quantum field theory approach

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Tobias Binder ◽  
Burkhard Blobel ◽  
Julia Harz ◽  
Kyohei Mukaida
Keyword(s):  
Field Theory ◽  
Quantum Field Theory ◽  
Dark Matter ◽  
State Formation ◽  
Bound State ◽  
Higher Order ◽  
Theory Approach ◽  
Quantum Field ◽  
The Impact ◽  
Non Equilibrium

Abstract The formation of meta-stable dark matter bound states in coannihilating scenarios could efficiently occur through the scattering with a variety of Standard Model bath particles, where light bosons during the electroweak cross over or even massless photons and gluons are exchanged in the t-channel. The amplitudes for those higher-order processes, however, are divergent in the collinear direction of the in- and out-going bath particles if the mediator is massless. To address the issue of collinear divergences, we derive the bound-state formation collision term in the framework of non-equilibrium quantum field theory. The main result is an expression for a more general cross section, which allows to compute higher-order bound-state formation processes inside the primordial plasma background in a comprehensive manner. Based on this result, we show that next-to-leading order contributions, including the bath-particle scattering, are i) collinear finite and ii) generically dominate over the on-shell emission for temperatures larger than the absolute value of the binding energy. Based on a simplified model, we demonstrate that the impact of these new effects on the thermal relic abundance is significant enough to make it worthwhile to study more realistic coannihilation scenarios.

scholarly journals Bound states of WIMP dark matter in Higgs-portal models. Part I. Cross-sections and transition rates

2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
Ruben Oncala ◽  
Kalliopi Petraki
Keyword(s):  
Dark Matter ◽  
Cross Sections ◽  
Bound States ◽  
Weak Interactions ◽  
Higgs Doublet ◽  
Bound State ◽  
Companion Paper ◽  
Fermionic Model ◽  
Higgs Portal

Abstract We investigate the role of the Higgs doublet in the thermal decoupling of multi-TeV dark matter coupled to the Weak interactions of the Standard Model and the Higgs. The Higgs doublet can mediate a long-range force that affects the annihilation processes and binds dark matter into bound states. More importantly, the emission of a Higgs doublet by a pair of dark matter particles can give rise to extremely rapid monopole bound-state formation processes and bound-to-bound transitions. We compute these effects in the unbroken electroweak phase. To this end, we consider the simplest renormalisable fermionic model, consisting of a singlet and a doublet under SUL(2) that are stabilised by a ℤ2 symmetry, in the regime where the two multiplets coannihilate. In a companion paper, we use the results to show that the formation of metastable bound states via Higgs-doublet emission and their decay decrease the relic density very significantly.

scholarly journals Seigneurial governance and the state in late medieval Guelders (14th–16th century)

2021 ◽  
Vol 36 (1) ◽  
pp. 33-59
Author(s):  
Jim van der Meulen
Keyword(s):  
State Formation ◽  
Cross Sections ◽  
Local Communities ◽  
The State ◽  
16Th Century ◽  
Modern State ◽  
Low Countries ◽  
Late Medieval ◽  
Central Argument

AbstractThis article charts the long-term development of seigneurial governance within the principality of Guelders in the Low Countries. Proceeding from four quantitative cross-sections (c. 1325, 1475, 1540, 1570) of seigneurial lordships, the conclusion is that seigneurial governance remained stable in late medieval Guelders. The central argument is that this persistence of seigneurial governance was an effect of active collaboration between princely administrations, lords, and local communities. Together, the princely government and seigneuries of Guelders formed an integrated, yet polycentric, state. The article thereby challenges the narrative of progressive state centralisation that predominates in the historiography of pre-modern state formation.

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