scholarly journals Observation of the new emission line at ~3.5 keV in X-ray spectra of galaxies and galaxy clusters

2016 ◽  
Vol 6 (1) ◽  
pp. 3-15 ◽  
Author(s):  
D. Iakubovskyi

The detection of an unidentified emission line in the X-ray spectra of cosmic objects would be a `smoking gun' signature for the particle physics beyond the Standard Model. More than a decade of its extensive searches results in several narrow faint emission lines reported at 3.5, 8.7, 9.4 and 10.1 keV. The most promising of them is the emission line at ~3.5 keV reported in spectra of several nearby galaxies and galaxy clusters. Here I summarize its up-to-date status, overview its possible interpretations, including an intriguing connection with the radiatively decaying dark matter, and outline future directions for its studies.


2014 ◽  
Vol 4 (1-2) ◽  
pp. 9-14 ◽  
Author(s):  
D. Iakubovskyi

Recent works of Bulbul et al. (2014) and Boyarsky et al. (2014), claiming the detection of the extra emission line with energy ∼3.5 keV in X-ray spectra of certain clusters of galaxies and nearby Andromeda galaxy, have raised a considerable interest in astrophysics and particle physics communities. A number of new observational studies claim detection or non-detection of the extra line in X-ray spectra of various cosmic objects. In this review I summarise existing results of these studies, overview possible interpretations of the extra line, including intriguing connection with radiatively decaying dark matter, and show future directions achievable with existing and planned X-ray cosmic missions.



Science ◽  
2020 ◽  
Vol 367 (6485) ◽  
pp. 1465-1467 ◽  
Author(s):  
Christopher Dessert ◽  
Nicholas L. Rodd ◽  
Benjamin R. Safdi

Observations of nearby galaxies and galaxy clusters have reported an unexpected x-ray emission line around 3.5 kilo–electron volts (keV). Proposals to explain this line include decaying dark matter—in particular, that the decay of sterile neutrinos with a mass around 7 keV could match the available data. If this interpretation is correct, the 3.5-keV line should also be emitted by dark matter in the halo of the Milky Way. We used more than 30 megaseconds of XMM-Newton (X-ray Multi-Mirror Mission) blank-sky observations to test this hypothesis, finding no evidence of the 3.5-keV line emission from the Milky Way halo. We set an upper limit on the decay rate of dark matter in this mass range, which is inconsistent with the possibility that the 3.5-keV line originates from dark matter decay.



2018 ◽  
Vol 33 (02) ◽  
pp. 1830003 ◽  
Author(s):  
John Ellis

The most important discovery in particle physics in recent years was that of the Higgs boson, and much effort is continuing to measure its properties, which agree obstinately with the Standard Model, so far. However, there are many reasons to expect physics beyond the Standard Model, motivated by the stability of the electroweak vacuum, the existence of dark matter and the origin of the visible matter in the Universe, neutrino physics, the hierarchy of mass scales in physics, cosmological inflation and the need for a quantum theory for gravity. Most of these issues are being addressed by the experiments during Run 2 of the LHC, and supersymmetry could help resolve many of them. In addition to the prospects for the LHC, I also review briefly those for direct searches for dark matter and possible future colliders.



Author(s):  
Junji Hisano

It is now certain that dark matter exists in the Universe. However, we do not know its nature, nor are there dark matter candidates in the standard model of particle physics or astronomy However, weakly interacting massive particles (WIMPs) in models beyond the standard model are one of the leading candidates available to provide explanation. The dark matter direct detection experiments, in which the nuclei recoiled by WIMPs are sought, are one of the methods to elucidate the nature of dark matter. This chapter introduces an effective field theory (EFT) approach in order to evaluate the nucleon–WIMP elastic scattering cross section.



2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Gary P. Centers ◽  
John W. Blanchard ◽  
Jan Conrad ◽  
Nataniel L. Figueroa ◽  
Antoine Garcon ◽  
...  

AbstractNumerous theories extending beyond the standard model of particle physics predict the existence of bosons that could constitute dark matter. In the standard halo model of galactic dark matter, the velocity distribution of the bosonic dark matter field defines a characteristic coherence time τc. Until recently, laboratory experiments searching for bosonic dark matter fields have been in the regime where the measurement time T significantly exceeds τc, so null results have been interpreted by assuming a bosonic field amplitude Φ0 fixed by the average local dark matter density. Here we show that experiments operating in the T ≪ τc regime do not sample the full distribution of bosonic dark matter field amplitudes and therefore it is incorrect to assume a fixed value of Φ0 when inferring constraints. Instead, in order to interpret laboratory measurements (even in the event of a discovery), it is necessary to account for the stochastic nature of such a virialized ultralight field. The constraints inferred from several previous null experiments searching for ultralight bosonic dark matter were overestimated by factors ranging from 3 to 10 depending on experimental details, model assumptions, and choice of inference framework.



Symmetry ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 112
Author(s):  
Maxim Khlopov

The physics of the dark Universe goes beyond the standard model (BSM) of fundamental interactions. The now-standard cosmology involves inflation, baryosynthesis and dark matter/energy corresponding to BSM physics. Cosmoparticle physics offers cross disciplinary study of the fundamental relationship of cosmology and particle physics in the combination of its physical, astrophysical and cosmological signatures. Methods of cosmoparticle physics in studies of BSM physics in its relationship with inevitably nonstandard features of dark universe cosmology are discussed. In the context of these methods, such exotic phenomena as primordial black holes, antimatter stars in baryon asymmetrical Universe or multi-charged constituents of nuclear interacting atoms of composite dark matter play the role of sensitive probes for BSM models and their parameters.



2015 ◽  
Vol 451 (3) ◽  
pp. 2447-2461 ◽  
Author(s):  
O. Urban ◽  
N. Werner ◽  
S. W. Allen ◽  
A. Simionescu ◽  
J. S. Kaastra ◽  
...  


2009 ◽  
Vol 5 (S268) ◽  
pp. 27-31
Author(s):  
Karsten Jedamzik

AbstractIn this proceeding I briefly discuss the possibility of relic decaying or annihilating particles to explain the cosmological 7Li anomaly and/or to be the source of significant amounts of pre-galactic 6Li. The effect of relic massive charged particles through catalysis of nuclear reactions is also discussed. The possibility of a connection of the 7Li problem to the cosmic dark matter and physics beyond the standard model of particle physics, such as supersymmetry, is noted.



Author(s):  
John Ellis

The Standard Model of particle physics agrees very well with experiment, but many important questions remain unanswered, among them are the following. What is the origin of particle masses and are they due to a Higgs boson? How does one understand the number of species of matter particles and how do they mix? What is the origin of the difference between matter and antimatter, and is it related to the origin of the matter in the Universe? What is the nature of the astrophysical dark matter? How does one unify the fundamental interactions? How does one quantize gravity? In this article, I introduce these questions and discuss how they may be addressed by experiments at the Large Hadron Collider, with particular attention to the search for the Higgs boson and supersymmetry.



2016 ◽  
Vol 31 (06) ◽  
pp. 1630005 ◽  
Author(s):  
Bibhushan Shakya

A sterile neutrino is a well-motivated and widely studied dark matter (DM) candidate. The most straightforward realization of sterile neutrino DM, through the Dodelson–Widrow (DW) mechanism, is now ruled out by a combination of X-ray and Lyman-[Formula: see text] measurements. An alternative production mechanism that is becoming increasingly popular in the literature is the freeze-in mechanism, involving frameworks where a feeble coupling to a particle — usually a scalar beyond the Standard Model — in the thermal bath results in a gradual accumulation of the sterile neutrino DM abundance. This paper reviews the various motivations for realizing such frameworks in the literature, their common characteristic features and phenomenological signatures.



Sign in / Sign up

Export Citation Format

Share Document