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| Author | : Carlos Fabian Jaramillo Gracia |
| Publisher | : |
| Total Pages | : 0 |
| Release | : 2023* |
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| ISBN | : |
| Author | : Alexander Merle |
| Publisher | : Morgan & Claypool Publishers |
| Total Pages | : 102 |
| Release | : 2017-05-10 |
| Genre | : Science |
| ISBN | : 1681744813 |
This book is a new look at one of the hottest topics in contemporary science, Dark Matter. It is the pioneering text dedicated to sterile neutrinos as candidate particles for Dark Matter, challenging some of the standard assumptions which may be true for some Dark Matter candidates but not for all. So, this can be seen either as an introduction to a specialized topic or an out-of-the-box introduction to the field of Dark Matter in general. No matter if you are a theoretical particle physicist, an observational astronomer, or a ground based experimentalist, no matter if you are a grad student or an active researcher, you can benefit from this text, for a simple reason: a non-standard candidate for Dark Matter can teach you a lot about what we truly know about our standard picture of how the Universe works.
| Author | : |
| Publisher | : |
| Total Pages | : 11 |
| Release | : 1993 |
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The simplest model that can accommodate a viable nonbaryonic dark matter candidate is the standard electroweak theory with the addition of right-handed or sterile neutrinos. This model has been studied extensively in the context of the hot dark matter scenario. We reexamine this model and find that hot, warm, and cold dark matter are all possibilities. We focus on the case where sterile neutrinos are the dark matter. Since their only direct coupling is to left-handed or active neutrinos, the most efficient production mechanism is via neutrino oscillations. If the production rate is always less than the expansion rate, then these neutrinos will never be in thermal equilibrium. However, they may still play a significant role in the dynamics of the Universe and possibly provide the missing mass necessary for closure. We consider a single generation of neutrino fields ([nu][sub L], [nu][sub R]) with a Dirac mass, [mu], and a Majorana mass for the right-handed components only, M. For M [much gt] [mu] we show that the number density of sterile neutrinos is proportional to [mu][sup 2]/M so that the energy density today is independent of M. However M is crucial in determining the large scale structure of the Universe. In particular, M [approx equal] 0.1--1.0 key leads to warm dark matter and a structure formation scenario that may have some advantages over both the standard hot and cold dark matter scenarios.
| Author | : Carlos Chichiri |
| Publisher | : |
| Total Pages | : 0 |
| Release | : 2022 |
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| ISBN | : |
Non-standard interactions (NSI) between active neutrinos (neutrinos belonging to the Standard Model) have the potential to modify the production of a fourth type of keV-scale mass neutrino (called "sterile"), due to active-sterile neutrino oscillations in the early Universe, a process known as the Dodelson-Widrow mechanism (DW). Through this modified DW mechanism, enough sterile neutrinos could be produced to account for the whole of the dark matter. This type of dark matter production occurred before big bang nucleosynthesis (BBN), an era just before the temperature of the Universe settled to 5 MeV, which is currently unknown. Thus, this type of dark matter production can be explored with different pre-BBN cosmological models. Taking into consideration the uncertainties in the pre-BBN cosmology besides the effects of NSI, we may identify a viable parameter space for sterile neutrino searches allowed by astrophysical limits and assess their effect on the range of mixing angles for keV-scale mass sterile neutrino dark matter. Detection of a sterile neutrino could provide insight into the pre-BBN era of the Universe. We find that the combined uncertainties in the early Universe cosmologies, as well as in the active neutrino interactions, significantly expand the allowed parameter space for sterile neutrinos that could constitute the whole of the dark matter. This thesis work will be published in a paper with the same title by C. Chichiri, G. Gelmini, P. Lu and V. Takhistov, already posted as a preprint in the arXiv,e-Print: 2.111.04087[hep-ph], and submitted for publication to the Journal of Cosmology and Astroparticle Physics (JCAP).
| Author | : A Merle |
| Publisher | : Myprint |
| Total Pages | : 102 |
| Release | : 2017-03-31 |
| Genre | : |
| ISBN | : 9781681748504 |
| Author | : Hans Volker Klapdor-Kleingrothaus |
| Publisher | : World Scientific |
| Total Pages | : 774 |
| Release | : 2011 |
| Genre | : Science |
| ISBN | : 9814340855 |
This book contains the proceedings of the Fifth International Conference on Physics Beyond the Standard Models of Particle Physics, Cosmology and Astrophysics. It presents a brilliant overview of the status and future potential and trends in experimental and theoretical particle physics, cosmology and astrophysics, in the complimentary sectors of accelerator, non-accelerator and space physics.
| Author | : Guido Altarelli |
| Publisher | : Springer |
| Total Pages | : 0 |
| Release | : 2004-02-24 |
| Genre | : Science |
| ISBN | : 3540449019 |
Reviews the current state of knowledge of neutrino masses and the related question of neutrino oscillations. After an overview of the theory of neutrino masses and mixings, detailed accounts are given of the laboratory limits on neutrino masses, astrophysical and cosmological constraints on those masses, experimental results on neutrino oscillations, the theoretical interpretation of those results, and theoretical models of neutrino masses and mixings. The book concludes with an examination of the potential of long-baseline experiments. This is an essential reference text for workers in elementary-particle physics, nuclear physics, and astrophysics.
| Author | : H. Ishida |
| Publisher | : |
| Total Pages | : 0 |
| Release | : 2014 |
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| Author | : F. Ferroni |
| Publisher | : IOS Press |
| Total Pages | : 493 |
| Release | : 2009-09-29 |
| Genre | : Science |
| ISBN | : 1607504502 |
This volume offers a valuable insight into various aspects of the ongoing work directed at measuring neutrino mass. It took twenty years to refute the assertions of Bethe and Peierls that neutrinos were not observable, but it has since been realised that much can be learnt from these particles. The moral is, as Fiorini argues here, that the study of neutrinos was and remains demanding but rewarding. Subjects addressed in this volume include; clarifying the meaning of the Klapdor-Kleingrothaus results, probing the Majorana nature of neutrinos, observing lepton number violating effects for the first time, studying the end point of the spectrum in the search for neutrino masses and speculating whether it is possible to measure neutrino masses in cosmology. Lectures are enriched with rich historical overviews and valuable introductory material. Attention is also given to theoretical topics such as the evolution of the concept of mass in particle physics, a status report on neutrino oscillations and current discussion on neutrino masses. The reader is further reminded that neutrino masses may also have some bearing on the very origin of the matter among us, and have many deep links with other important lines of current physics research.
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| Total Pages | : |
| Release | : 2016 |
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Sterile neutrinos can be generated in the early universe through oscillations with active neutrinos and represent a popular and well-studied candidate for our universe's dark matter. Stringent constraints from X-ray and gamma-ray line searches, however, have excluded the simplest of such models. In this letter, we propose a novel alternative to the standard scenario in which the mixing angle between the sterile and active neutrinos is a dynamical quantity, induced through interactions with a light axion-like field. As the energy density of the axion-like particles is diluted by Hubble expansion, the degree of mixing is reduced at late times, suppressing the decay rate and easily alleviating any tension with X-ray or gamma-ray constraints. We present a simple model which illustrates the phenomenology of this scenario, and also describe a framework in which the QCD axion is responsible for the production of sterile neutrinos in the early universe.
