scholarly journals Role of future lepton colliders for fermionic Z -portal dark matter models

2020 ◽  
Vol 101 (1) ◽  
Author(s):  
Dilip Kumar Ghosh ◽  
Taisuke Katayose ◽  
Shigeki Matsumoto ◽  
Ipsita Saha ◽  
Satoshi Shirai ◽  
...  
Keyword(s):  
2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
Roberto A. Lineros ◽  
Mathias Pierre

Abstract We explore the connection between Dark Matter and neutrinos in a model inspired by radiative Type-II seessaw and scotogenic scenarios. In our model, we introduce new electroweakly charged states (scalars and a vector-like fermion) and impose a discrete ℤ2 symmetry. Neutrino masses are generated at the loop level and the lightest ℤ2-odd neutral particle is stable and it can play the role of a Dark Matter candidate. We perform a numerical analysis of the model showing that neutrino masses and flavour structure can be reproduced in addition to the correct dark matter density, with viable DM masses from 700 GeV to 30 TeV. We explore direct and indirect detection signatures and show interesting detection prospects by CTA, Darwin and KM3Net and highlight the complementarity between these observables.


Author(s):  
Alexandres Lazar ◽  
James S Bullock ◽  
Michael Boylan-Kolchin ◽  
Robert Feldmann ◽  
Onur Çatmabacak ◽  
...  

Abstract A promising route for revealing the existence of dark matter structures on mass scales smaller than the faintest galaxies is through their effect on strong gravitational lenses. We examine the role of local, lens-proximate clustering in boosting the lensing probability relative to contributions from substructure and unclustered line-of-sight (LOS) haloes. Using two cosmological simulations that can resolve halo masses of Mhalo ≃ 109 M⊙ (in a simulation box of length Lbox ∼ 100 Mpc) and 107 M⊙ (Lbox ∼ 20 Mpc), we demonstrate that clustering in the vicinity of the lens host produces a clear enhancement relative to an assumption of unclustered haloes that persists to >20 Rvir. This enhancement exceeds estimates that use a two-halo term to account for clustering, particularly within 2 − 5 Rvir. We provide an analytic expression for this excess, clustered contribution. We find that local clustering boosts the expected count of 109 M⊙ perturbing haloes by ${\sim }35{{\ \rm per\ cent}}$ compared to substructure alone, a result that will significantly enhance expected signals for low-redshift (zl ≃ 0.2) lenses, where substructure contributes substantially compared to LOS haloes. We also find that the orientation of the lens with respect to the line of sight (e.g. whether the line of sight passes through the major axis of the lens) can also have a significant effect on the lensing signal, boosting counts by an additional $\sim 50{{\ \rm per\ cent}}$ compared to a random orientations. This could be important if discovered lenses are biased to be oriented along their principal axis.


1994 ◽  
Vol 50 (12) ◽  
pp. 7128-7143 ◽  
Author(s):  
V. A. Bednyakov ◽  
H. V. Klapdor-Kleingrothaus ◽  
S. G. Kovalenko

Author(s):  
Michael A. Persinger

The Borowski Theory of Gravitation (BTG) indicates that movements of mass such as planets through space are determined by differential pressures from dark matter. One of the consequences of the final epoch is that there would be no matter but only distance. Quantitative solutions indicate that the tensor to set universal average dark matter pressure equal to G, the gravitational constant, would require that the terminal length would be ~2.2∙1069 m or effectively identical to current estimates of energy equivalence of the universal mass. For the earth’s orbit the force from the dark pressure is the same order of magnitude as the force associated with the product of the planet’s mass and background free oscillations whose origins are still ambiguous. The convergences of solutions suggest that the BTG may reveal alternative interpretations and mechanisms for the role of gravitation in planetary motion.


Author(s):  
Simon Daley

The PICO experiment uses superheated bubble chambers located at SNOLAB for direct detection of Weakly Interacting Massive Particles (WIMPs), one of the candidate particles for dark matter. Bubbles form in the detector when a particle interacts with a nucleus of the target fluid, and the recoiling deposits enough energy to nucleate a bubble in the superheated fluid. Much of the data analysis for PICO focuses on determining what type of particle caused a bubble to form. The differentiation is made by analysing signals from pressure sensors, piezoelectric acoustic sensors, and stereoscopic cameras. This talk will present an overview of the sensors and analysis which are used to discriminate between WIMP interactions and background events in the PICO 2L detector, with a focus on the role of image analysis and the potential sensitivity of the detector if good discrimination can be realized.


2018 ◽  
Vol 48 ◽  
pp. 8-15 ◽  
Author(s):  
Xiaowen Hu ◽  
Anil K Sood ◽  
Chi V Dang ◽  
Lin Zhang

New Astronomy ◽  
2015 ◽  
Vol 41 ◽  
pp. 48-52
Author(s):  
Eduardo S. Pereira ◽  
Oswaldo D. Miranda

2020 ◽  
Vol 80 (8) ◽  
Author(s):  
Pravin Kumar Natwariya ◽  
Jitesh R. Bhatt ◽  
Arun Kumar Pandey

Abstract The effective theory of large-scale structure formation based on $$\Lambda $$ΛCDM paradigm predicts finite dissipative effects in the resulting fluid equations. In this work, we study how viscous effect that could arise if one includes self-interaction among the dark-matter particles combines with the effective theory. It is shown that these two possible sources of dissipation can operate together in a cosmic fluid and the interplay between them can play an important role in determining dynamics of the cosmic fluid. In particular, we demonstrate that the viscosity coefficient due to self-interaction is added inversely with the viscosity calculated using effective theory of $$\Lambda $$ΛCDM model. Thus the larger viscosity has less significant contribution in the effective viscosity. Using the known bounds on $$\sigma /m$$σ/m for self-interacting darkmatter, where $$\sigma $$σ and m are the cross-section and mass of the dark-matter particles respectively, we discuss role of the effective viscosity in various cosmological scenarios.


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