scholarly journals Final state Sommerfeld effect on dark matter relic abundance

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Xiaoyi Cui ◽  
Feng Luo
Keyword(s):  
Dark Matter ◽  
Long Range ◽  
Sommerfeld Effect ◽  
Initial State ◽  
Final State ◽  
Range Interaction ◽  
State Pair ◽  
The Masses ◽  
Relic Abundance ◽  
The Impact

Abstract If the annihilation products of dark matter (DM) are non-relativistic and if there is some long-range force between them, there can be Sommerfeld effect for the final state particles. We study this effect on DM relic abundance in the thermal freeze-out scenario. As a proof of concept, we consider the case of a DM pair annihilation into a final state pair, assuming that the mutual interactions between the two final state particles give rise to a Coulomb-like potential, and that the masses of the initial and final state particles are similar, so that both the initial and final state particles are non-relativistic. The size of the final state Sommerfeld (FSS) effect depends on the strength of the potential, as well as on the mass ratio of the final and initial state particles. We find that the impact of the FSS effect on DM relic abundance can be significant, and an electroweak sized long-range interaction is large enough to make a correction well beyond the observational accuracy. Another feature of the FSS effect is that it could be suppressed when its time scale is longer than the lifetime of the final state particles. As a corollary, we also study in the DM coannihilation scenario where the initial state Sommerfeld effect between two coannihilators could be reduced due to their instability, which may need to be taken into account for an accurate calculation of the DM relic abundance.

scholarly journals Correlations in the Initial Conditions of Heavy-Ion Collisions

2020 ◽  
Vol 235 ◽  
pp. 08002 ◽  
Author(s):  
Douglas Wertepny ◽  
Jacquelyn Noronha-Hostler ◽  
Matthew Sievert ◽  
Skandaprasad Rao ◽  
Noah Paladino
Keyword(s):  
Initial Conditions ◽  
Heavy Ion ◽  
Color Glass ◽  
Heavy Nuclei ◽  
Initial State ◽  
Final State ◽  
Microscopic Mechanism ◽  
Ion Collisions ◽  
The Impact ◽  
Initial Geometry

Ultracentral collisions of heavy nuclei, in which the impact parameter is nearly zero, are especially sensitive to the details of the initial state model and the microscopic mechanism for collective flow. In a hydrodynamic “flow” picture, the final state momentum correlations are a direct response to the fluctuating initial geometry, although models of the initial geometry differ widely. Alternatively, dynamical mechanisms based in the color glass condensate (CGC) formalism can naturally lead to many-body correlations with very different systematics. Here we present a calculation of event-by-event elliptic flow in both the hydrodynamic and CGC paradigms and show that they can be qualitatively distinguished in ultracentral collisions of deformed nuclei. Specifically, the multiplicity dependence in such collisions is qualitatively opposite, with the CGC correlations increasing with multiplicity while the hydrodynamic correlations decrease. The consistency of the latter with experimental data on UU collisions appears to rule out a CGC-mediated explanation. We find that these qualitative features also persist in small deformed systems and can therefore be a valuable test of the microscopic physics in that regime. The authors acknowledge support from the US-DOE Nuclear Science Grant No. DE-SC0019175, and the Alfred P. Sloan Foundation, and the Zuckerman STEM Leadership Program.

scholarly journals Sensitivity of future linear $$\hbox {e}^+\hbox {e}^-$$ colliders to processes of dark matter production with light mediator exchange

2021 ◽  
Vol 81 (10) ◽  
Author(s):  
Jan Kalinowski ◽  
Wojciech Kotlarski ◽  
Krzysztof Mȩkała ◽  
Paweł Sopicki ◽  
Aleksander Filip Żarnecki
Keyword(s):  
Dark Matter ◽  
Linear Collider ◽  
Production Cross ◽  
Photon Emission ◽  
International Linear Collider ◽  
High Energy ◽  
Initial State ◽  
Final State ◽  
State Radiation ◽  
Wide Range

AbstractAs any $$e^+e^-$$ e + e - scattering process can be accompanied by a hard photon emission from the initial state radiation, the analysis of the energy spectrum and angular distributions of those photons can be used to search for hard processes with an invisible final state. Thus high energy $$e^+e^-$$ e + e - colliders offer a unique possibility for the most general search of dark matter (DM) based on the mono-photon signature. We consider production of DM particles at the International Linear Collider (ILC) and Compact Linear Collider (CLIC) experiments via a light mediator exchange. Detector effects are taken into account within the Delphes fast simulation framework. Limits on the light DM production in a simplified model are set as a function of the mediator mass and width based on the expected two-dimensional distributions of the reconstructed mono-photon events. The experimental sensitivity is extracted in terms of the DM production cross section. Limits on the mediator couplings are then presented for a wide range of mediator masses and widths. For light mediators, for masses up to the centre-of-mass energy of the collider, coupling limits derived from the mono-photon analysis are more stringent than those expected from direct resonance searches in decay channels to SM particles.

scholarly journals Machine learning the fates of dark matter subhaloes: a fuzzy crystal ball

2021 ◽  
Vol 504 (1) ◽  
pp. 248-266
Author(s):  
Abigail Petulante ◽  
Andreas A Berlind ◽  
J Kelly Holley-Bockelmann ◽  
Manodeep Sinha
Keyword(s):  
Machine Learning ◽  
Dark Matter ◽  
Mass Loss ◽  
Impact Angle ◽  
Dark Matter Halo ◽  
Mass Ratio ◽  
Merging Process ◽  
The Masses ◽  
Almost All ◽  
The Impact

ABSTRACT The evolution of a dark matter halo in a dark matter only simulation is governed purely by Newtonian gravity, making a clean testbed to determine what halo properties drive its fate. Using machine learning, we predict the survival, mass loss, final position, and merging time of subhaloes within a cosmological N-body simulation, focusing on what instantaneous initial features of the halo, interaction, and environment matter most. Survival is well predicted, with our model achieving 94.25 per cent out-of-bag accuracy using only three model inputs (redshift, subhalo-to-host-halo mass ratio, and the impact angle of the subhalo into its host) taken at the time immediately before the subhalo enters its host. However, the mass loss, final location, and merging times are much more stochastic processes, with significant errors between true and predicted quantities for much of our sample. Only five inputs (redshift, impact angle, relative velocity, and the masses of the host and subhalo) determine almost all of the subhalo evolution learned by our models. Generally, subhaloes that enter their hosts at a mid-range of redshifts (z = 0.67–0.43) are the most challenging to make predictions for, across all of our final outcomes. Subhalo orbits that come in more perpendicular to the host are easier to predict, except for in the case of predicting disruption, where the opposite appears to be true. We conclude that the detailed evolution of individual subhaloes within N-body simulations is difficult to predict, pointing to a stochasticity in the merging process. We discuss implications for both simulations and observations.

scholarly journals Singularities in the gravitational capture of dark matter through long-range interactions

2022 ◽  
Vol 2022 (01) ◽  
pp. 016
Author(s):  
Cristian Gaidau ◽  
Jessie Shelton
Keyword(s):  
Dark Matter ◽  
Long Range ◽  
Capture Rate ◽  
Thermal Motion ◽  
The Sun ◽  
Long Range Interactions ◽  
Population Iii Stars ◽  
Logarithmic Sensitivity ◽  
Gravitational Capture ◽  
The Impact

Abstract We re-examine the gravitational capture of dark matter (DM) through long-range interactions. We demonstrate that neglecting the thermal motion of target particles, which is often a good approximation for short-range capture, results in parametrically inaccurate results for long-range capture. When the particle mediating the scattering process has a mass that is small in comparison to the momentum transfer in scattering events, correctly incorporating the thermal motion of target particles results in a quadratic, rather than logarithmic, sensitivity to the mediator mass, which substantially enhances the capture rate. We quantitatively assess the impact of this finite temperature effect on the captured DM population in the Sun as a function of mediator mass. We find that capture of DM through light dark photons, as in e.g. mirror DM, can be powerfully enhanced, with self-capture attaining a geometric limit over much of parameter space. For visibly-decaying dark photons, thermal corrections are not large in the Sun, but may be important in understanding long-range DM capture in more massive bodies such as Population III stars. We additionally provide the first calculation of the long-range DM self-evaporation rate.

scholarly journals Lepton dark matter portal in the inert Zee model

2020 ◽  
Vol 35 (31) ◽  
pp. 2050190
Author(s):  
Alexandra Gaviria ◽  
Robinson Longas ◽  
Andrés Rivera
Keyword(s):  
Dark Matter ◽  
Parameter Space ◽  
Tree Level ◽  
Neutrino Masses ◽  
Dark Matter Annihilation ◽  
Annihilation Channel ◽  
Flavor Changing ◽  
Inert Doublet Model ◽  
Relic Abundance ◽  
The Impact

The inert Zee model is an extension of the Zee model for neutrino masses. This new model explains the dark matter relic abundance, generates a one-loop neutrino masses and forbids tree-level Higgs-mediated flavor changing neutral currents. Although the dark matter phenomenology of the model is similar to that of the inert doublet model, the presence of new vector-like fermions opens the lepton portal as a new dark matter annihilation channel. We study the impact of this new portal in the low-mass regime and show the parameter space allowed by direct and indirect searches of dark matter. Remarkably, the region for [Formula: see text] GeV is recovered for [Formula: see text]. We also show that future experiments like LZ and DARWIN could probe a large region of the parameter space of the model.

scholarly journals Sommerfeld-corrected relic abundance of wino dark matter with NLO electroweak potentials

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Martin Beneke ◽  
Robert Szafron ◽  
Kai Urban
Keyword(s):  
Dark Matter ◽  
Sommerfeld Effect ◽  
Leading Order ◽  
Loop Order ◽  
The One ◽  
Relic Abundance

Abstract Extending previous work, we calculate the electroweak potentials for all co-annihilation channels of wino dark matter at the one-loop order and obtain the wino relic abundance including the Sommerfeld effect at the next-to-leading order (NLO).

scholarly journals Reconciling Higgs physics and pseudo-Nambu-Goldstone dark matter in the S2HDM using a genetic algorithm

2021 ◽  
Vol 2021 (10) ◽  
Author(s):  
Thomas Biekötter ◽  
María Olalla Olea-Romacho
Keyword(s):  
Genetic Algorithm ◽  
Dark Matter ◽  
Cross Sections ◽  
Direct Detection ◽  
Scalar Potential ◽  
Higgs Sector ◽  
Higgs Doublet ◽  
Final State ◽  
The One ◽  
Relic Abundance

Abstract We investigate a possible realization of pseudo-Nambu-Goldstone (pNG) dark matter in the framework of a singlet-extended 2 Higgs doublet model (S2HDM). pNG dark matter gained attraction due to the fact that direct-detection constraints can be avoided naturally because of the momentum-suppressed scattering cross sections, whereas the relic abundance of dark matter can nevertheless be accounted for via the usual thermal freeze-out mechanism. We confront the S2HDM with a multitude of theoretical and experimental constraints, paying special attention to the theoretical limitations on the scalar potential, such as vacuum stability and perturbativity. In addition, we discuss the complementarity between constraints related to the dark matter sector, on the one hand, and to the Higgs sector, on the other hand. In our numerical discussion we explore the Higgs funnel region with dark matter masses around 60 GeV using a genetic algorithm. We demonstrate that the S2HDM can easily account for the measured relic abundance while being in agreement with all relevant constraints. We also discuss whether the so-called center-of-galaxy excesses can be accommodated, possibly in combination with a Higgs boson at about 96 GeV that can be the origin of the LEP- and the CMS-excess observed at this mass in the b$$ \overline{b} $$ b ¯ -quark and the diphoton final state, respectively.

scholarly journals Influence of Initial State Errors on Perturbation Guidance Accuracy

2019 ◽  
Vol 69 (1) ◽  
pp. 10-19
Author(s):  
Wuxing Jing ◽  
Xu Zheng ◽  
Changsheng Gao
Keyword(s):  
Long Range ◽  
Propagation Model ◽  
Impact Point ◽  
Initial State ◽  
The Real ◽  
Guidance And Control ◽  
Influence Mechanism ◽  
The Earth ◽  
And Control ◽  
The Impact

The inertial navigation system is aligned and leveled before the launch of a long-range vehicle. However, the initial state errors caused by the non-uniformity of the Earth can influence the parameters in flight dynamics, which will bring about serious uncertainty for the impact point of a long-range vehicle. Firstly, this paper analyses the influence mechanism of initial state errors on nominal trajectory, navigation trajectory and guidance trajectory. Then, a propagation model of engine-cutoff state deviation caused by initial state errors is derived under the condition of without-guidance. On this basis, an accuracy analytical solution of initial state errors on perturbation guidance is finally proposed to obtain the real impact-point of the long-range vehicle. In the simulations, the influence properties of initial state errors on perturbation guidance is analysed, give influence regularities of single initial state error, and obtain the statistical properties of engine-cutoff state deviations and impact-point deviation by Monte Carlo technique. From the simulation results, it seems that the navigation state tracks the nominal state. However, the real impact- point deviation has not been truly eliminated, instead of the almost target-hit deviation calculated by navigation output. The proposed analytical guidance accuracy model can be rapidly computed to provide a compensation for guidance and control system to improve hit accuracy.

scholarly journals Temperature Dependences of the Quantum-Mechanical and Semi-Classical Spectral-Line Widths and the Separation of the Impact and Non-Impact Regions for an Ar-Perturbed/K-Radiator System

2010 ◽  
Vol 2010 ◽  
pp. 1-6
Author(s):  
W. C. Kreye
Keyword(s):  
Spectral Line ◽  
Basic Parameter ◽  
The State ◽  
Quantum Mechanical ◽  
Initial State ◽  
Final State ◽  
Line Shapes ◽  
The Impact ◽  
Radiator System ◽  
Impact Region

Quantum-mechanical and semi-classical spectral-line shapes are computed at , , and  K for the line core of the 5802 Å line of the Ar-Perturbed/K-Radiator system. HWHMs ('s) are measured from computed full spectral-line shapes. The final-state pseudopotential is for the state, and the initial-state potential is for the state. Three high-pressure (P) —versus— curves, corresponding to the non-impact region, intersect a similar set of low-P, impact-region curves at intersections, 's. Similarly, for two sets of —versus— curves, which yield intersections, 's, where is the perturber density. These 's and 's separate the two regions and represent the upper limits of the impact regions. A specific validity condition for the impact region is given by the equation . From an earlier spectroscopic, Fabry-Perot paper,  cm−1 at  K and torr. Two theoretical values, and  cm−1 corresponding to two different pseudo-potentials, are reported. Two -dependent figures are given, in which the first shows an increase in the impact region with , based on as the basic parameter, and the second which shows a decrease in the impact region with , based on as the basic parameter.

scholarly journals Spin-dependence of gravity-mediated dark matter in warped extra-dimensions

2021 ◽  
Vol 81 (3) ◽  
Author(s):  
Miguel G. Folgado ◽  
Andrea Donini ◽  
Nuria Rius
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Parameter Space ◽  
Vector Boson ◽  
Link Type ◽  
The Standard Model ◽  
Linear Dilaton ◽  
Relic Abundance ◽  
The Impact ◽  
Kaluza Klein

AbstractWe study the possibility that Dark Matter (DM) particles of spin 0, 1/2 or 1 may interact gravitationally with Standard Model (SM) particles within the framework of a warped Randall–Sundrum (RS) model. Both the Dark Matter and the Standard Model particles are assumed to be confined to the infra-red (IR) brane and only interchange Kaluza–Klein excitations of the graviton and the radion (adopting the Goldberger–Wise mechanism to stabilize the size of the extra-dimension). We analyze the different DM annihilation channels and find that the presently observed Dark Matter relic abundance, $$\Omega _{\mathrm{DM}}$$ Ω DM , can be obtained within the freeze-out mechanism for DM particles of all considered spins. This extends our first work concerning scalar DM in RS scenarios (Folgado et al., in JHEP 01:161. 10.1007/JHEP01(2020)161, 2020) and put it on equal footing with our second work in which we studied DM particles of spin 0, 1/2 and 1 in the framework of the Clockwork/Linear Dilaton (CW/LD) model (Folgado et al., in JHEP 20:036. 10.1007/JHEP04(2020)036, 2020). We study the region of the model parameter space for which $$\Omega _{\mathrm{DM}}$$ Ω DM is achieved and compare it with the different experimental and theoretical bounds. We find that, for DM particles mass $$m_{\mathrm{DM}} \in [1,15]$$ m DM ∈ [ 1 , 15 ] TeV, most of the parameter space is excluded by the current constraints or will be excluded by the LHC Run III or by the LHC upgrade, the HL-LHC. The observed DM relic abundance can still be achieved for DM masses $$m_{\mathrm{DM}} \in [4,15]$$ m DM ∈ [ 4 , 15 ] TeV and $$m_{G_1} < 10$$ m G 1 < 10 TeV for scalar and vector boson Dark Matter. On the other hand, for spin 1/2 fermion Dark Matter, only a tiny region with $$m_{\mathrm{DM }} \in [4, 15]$$ m DM ∈ [ 4 , 15 ] TeV, $$m_{G_1} \in [5,10]$$ m G 1 ∈ [ 5 , 10 ] TeV and $$\Lambda > m_{G_1}$$ Λ > m G 1 is compatible with theoretical and experimental bounds. We have also studied the impact of the radion in the phenomenology, finding that it does not modify significantly the allowed region for DM particles of any spin (differently from the CW/LD case, where its impact was quite significant in the case of scalar DM). We, eventually, briefly compare results in RS with those obtained in the CW/LD model.

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