Recherche

Afficher tous les résultats pour

Accueil

Personne

Oleg Ruchayskiy

Cette personne a quitté l’EPFL

À propos
Confidentialité
Mentions légales

Graph Chatbot

Publications associées (44)

Page 2 sur 3

Measurement of the muon flux from 400 GeV/c protons interacting in a thick molybdenum/tungsten target

Aurelio Bay, Mikhail Chapochnikov, Guido Haefeli, Alexey Boyarsky, Alexandre Emmanuel Grandchamp, Oleg Ruchayskiy, Lesya Shchutska, Nikolaos Charitonidis, Jean-Loup Tastet, Ekaterina Kuznetsova, Inar Timiryasov, Maria Elena Stramaglia, Ana Bárbara Rodrigues Cavalcante, Federico Leo Redi, Elena Graverini

The SHiP experiment is proposed to search for very weakly interacting particles beyond the Standard Model which are produced in a 400 GeV/c proton beam dump at the CERN SPS. About 1011muons per spill will be produced in the dump. To design the experiment s ...

2020

Unidentified Line in X-Ray Spectra of the Andromeda Galaxy and Perseus Galaxy Cluster

Alexey Boyarsky, Oleg Ruchayskiy

We report a weak line at 3.52 +/- 0.02 keV in x-ray spectra of the Andromeda galaxy and the Perseus galaxy cluster observed by the metal-oxide-silicon (MOS) and p-n (PN) CCD cameras of the XMM-Newton telescope. This line is not known as an atomic line in t ...

Amer Physical Soc2014

The role of sterile neutrinos in cosmology and astrophysics

Mikhail Chapochnikov, Alexey Boyarsky, Oleg Ruchayskiy

We present a comprehensive overview of an extension of the Standard Model that contains three right-handed (sterile) neutrinos with masses below the electroweak scale [the Neutrino Minimal Standard Model (vMSM)]. We consider the history of the Universe fro ...

Annual Reviews2009

The masses of active neutrinos in the nuMSM from X-ray astronomy

Mikhail Chapochnikov, Alexey Boyarsky, Oleg Ruchayskiy

In an extension of the Standard Model by three relatively light right-handed neutrinos (the νMSM model) the role of the dark matter particle is played by the lightest sterile neutrino. We demonstrate that the observations of the extragalactic x-ray backgro ...

2006

An allowed window for heavy neutral leptons below the kaon mass

Alexey Boyarsky, Oleg Ruchayskiy, Inar Timiryasov, Juraj Klaric, Kyrylo Bondarenko

The extension of the Standard Model with two gauge-singlet Majorana fermions can simultaneously explain two beyond-the-Standard-model phenomena: neutrino masses and oscillations, as well as the origin of the matter-antimatter asymmetry in the Universe. The ...

Springer Nature2021

Decaying dark matter: the case for a deep X-ray observation of Draco

Alexey Boyarsky, Oleg Ruchayskiy

Recent studies of M31, the Galactic Centre (GC), and galaxy clusters have made tentative detections of an X-ray line at similar to 3.5 keV that could be produced by decaying dark matter. We use high-resolution simulations of the Aquarius project to predict ...

Oxford University Press2015

A facility to search for hidden particles at the CERN SPS: the SHiP physics case

Mikhail Chapochnikov, Alexey Boyarsky, Oleg Ruchayskiy, Lesya Shchutska, Marco Drewes, Shintaro Eijima, Kyrylo Bondarenko

This paper describes the physics case for a new fixed target facility at CERN SPS. The SHiP (search for hidden particles) experiment is intended to hunt for new physics in the largely unexplored domain of very weakly interacting particles with masses below ...

Institute of Physics2016

Feebly-Interacting Particles:FIPs 2020 Workshop Report

Alexey Boyarsky, Oleg Ruchayskiy, Lesya Shchutska, Marco Drewes

With the establishment and maturation of the experimental programs searching for new physics with sizeable couplings at the LHC, there is an increasing interest in the broader particle and astrophysics community for exploring the physics of light and feebl ...

2021

The magnet of the scattering and neutrino detector for the SHiP experiment at CERN

Sebastian Gerlach, Aurelio Bay, Mikhail Chapochnikov, Guido Haefeli, Alexey Boyarsky, Sun Hee Kim, Alexandre Emmanuel Grandchamp, Oleg Ruchayskiy, Lesya Shchutska, Nikolaos Charitonidis, Jean-Loup Tastet, Ekaterina Kuznetsova, Inar Timiryasov, Maria Elena Stramaglia, Ana Bárbara Rodrigues Cavalcante, Federico Leo Redi, Elena Graverini

The Search for Hidden Particles (SHiP) experiment proposal at CERN demands a dedicated dipole magnet for its scattering and neutrino detector. This requires a very large volume to be uniformly magnetized at B > 1.2 T, with constraints regarding the inner i ...

2020

The present and future status of heavy neutral leptons

Alexey Boyarsky, Oleg Ruchayskiy, Lesya Shchutska, Marco Drewes, Jean-Loup Tastet, Inar Timiryasov, Juraj Klaric

The existence of nonzero neutrino masses points to the likely existence of multiple Standard Model neutral fermions. When such states are heavy enough that they cannot be produced in oscillations, they are referred to as heavy neutral leptons (HNLs). In th ...

2022

Probing new physics with displaced vertices: Muon tracker at CMS

Alexey Boyarsky, Oleg Ruchayskiy, Lesya Shchutska, Kyrylo Bondarenko

Long-lived particles can manifest themselves at the LHC via "displaced vertices"-several charged tracks originating from a position separated from the proton interaction point by a macroscopic distance. Here we demonstrate the potential of the muon tracker ...

American Physical Society2019

Restrictions on parameters of sterile neutrino dark matter from observations of galaxy clusters

Mikhail Chapochnikov, Alexey Boyarsky, Oleg Ruchayskiy

We find restrictions on the mass and mixing angle of the dark matter sterile neutrinos using x-ray observations of Coma and Virgo galaxy clusters with XMM-Newton satellite. In the absence of clearly detectable line, we present detailed analysis of various ...

American Physical Society2006

Constraints on sterile neutrino as a dark matter candidate from the diffuse X-ray background

Mikhail Chapochnikov, Alexey Boyarsky, Oleg Ruchayskiy

Sterile neutrinos with masses in the kilo-electronvolt range are viable candidates for the warm dark matter. We analyse existing data for the extragalactic diffuse X-ray background for signatures of sterile neutrino decay. The absence of a detectable signa ...

2006

Next decade of sterile neutrino studies

Alexey Boyarsky, Oleg Ruchayskiy

We review the status of sterile neutrino dark matter and discuss astrophysical and cosmological bounds on its properties as well as future prospects for its experimental searches. We argue that if sterile neutrinos are the dominant fraction of dark matter, ...

2012

Sensitivity of the SHiP experiment to dark photons decaying to a pair of charged particles

Dark photons are hypothetical massive vector particles that could mix with ordinary photons. The simplest theoretical model is fully characterised by only two parameters: the mass of the dark photon m(gamma)D and its mixing parameter with the photon, epsil ...

2021

Universal Properties of Dark Matter Halos

Igor Tkachev, Alexey Boyarsky, Oleg Ruchayskiy

We discuss the universal relation between density and size of observed dark matter halos that was recently shown to hold on a wide range of scales, from dwarf galaxies to galaxy clusters. Predictions of cold dark matter (Lambda CDM) N-body simulations are ...

2010

Magnetohydrodynamics of chiral relativistic fluids

Alexey Boyarsky, Oleg Ruchayskiy

We study the dynamics of a plasma of charged relativistic fermions at very high temperature T >> m, where m is the fermion mass, coupled to the electromagnetic field. In particular, we derive a magnetohydrodynamical description of the evolution of such a p ...

American Physical Society2015

Tag Recommendation for Large-Scale Ontology-Based Information Systems

Philippe Cudré-Mauroux, Karl Aberer, Alexey Boyarsky, Oleg Ruchayskiy, Roman Prokofyev

We tackle the problem of improving the relevance of automatically selected tags in large-scale ontology-based information systems. Contrary to traditional settings where tags can be chosen arbitrarily, we focus on the problem of recommending tags (e.g., co ...

Springer2012

Checking the Dark Matter Origin of a 3.53 keV Line with the Milky Way Center

Alexey Boyarsky, Oleg Ruchayskiy

We detect a line at 3.539 +/- 0.011 keV in the deep exposure data set of the Galactic center region, observed with the x-ray multi-mirror mission Newton. The dark matter interpretation of the signal observed in the Perseus galaxy cluster, the Andromeda gal ...

Amer Physical Soc2015

Anomalies as a signature of extra dimensions

Mikhail Chapochnikov, Alexey Boyarsky, Oleg Ruchayskiy

The anomaly cancellation condition of the Standard Model may be unnatural in theories with extra dimensions as an anomaly of a low-energy 4-dimensional theory can be canceled by an inflow from a bulk. This inflow may give rise to an observable effect at lo ...

2005