Mikhail Chapochnikov

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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 ...

We report the observation of neutrino interactions without final state muons at the LHC, with a significance of 6.4σ. A dataset of proton-proton collisions at s=13.6 TeV collected by SND@LHC in 2022 and 2023 is used, corresponding to an integrated luminosi ...

An extension of the minimal standard model by three right-handed neutrinos with masses smaller than the electroweak scale (the νMSM) allows to explain simultaneously neutrino oscillations and dark matter in the universe. We show how to fix the absolute val ...

The ωρπ coupling constant is calculated using a modified form of sum rules for the vertex function 〈0|T(Jμ(x), Jν(0))|π〉 accounting for the axial anomaly. The result gωρπ=16 GeV-1 is in good agreement with the estimates of the Vector Meson Dominance model. We show that the standard procedure gives for gωρπ a considerably smaller value compared to the experimental number. © 1988 Springer-Verlag.

Supersymmetric extensions of the Standard Model contain nontopological solitons, Q-balls, which can be stable and can be a form of cosmological dark matter. Understanding the interaction of SUSY Q-balls with matter fermions is important for both astrophysi ...

We describe a possible creation of an odd number of fractionally charged fermions in the 1+1 dimensional Abelian Higgs model. We point out that for 1+1 dimensions this process does not violate any symmetries of the theory, nor makes it mathematically incon ...

Dark matter is a well-established theoretical addition to the Standard Model supported by many observations in modern astrophysics and cosmology. In this context, the existence of weakly interacting massive particles represents an appealing solution to the ...

If gravity is asymptotically safe, then the ultimate theory might be just the standard model (minimally supplemented by a few light particles to accommodate neutrino masses and oscillations, dark matter, and the baryon asymmetry of the Universe) plus gravi ...

In the cosmological context, for the Standard Model to be valid up to the scale of inflation, the top quark Yukawa coupling y (t) should not exceed the critical value y (t) (crit) , coinciding with good precision (about 0.2aEuro degrees) with the requireme ...

Radiatively decaying dark matter may be searched through investigating the photon spectrum of galaxies and galaxy clusters. We explore whether the properties of dark matter can be constrained through the study of a polarization state of emitted photons. St ...

We calculate the baryon asymmetry of the Universe which would arise during a first-order electroweak phase transition due to minimal-standard-model processes. It agrees in sign and magnitude with the observed baryonic excess, for reasonable Kobayashi-Maskawa parameters and mt in the expected range, and plausible values of bubble velocity and other high temperature effects. © 1993 The American Physical Society.

We discuss the lower Higgs boson mass bounds which come from the absolute stability of the Standard Model (SM) vacuum and from the Higgs inflation, as well as the prediction of the Higgs boson mass coming from the asymptotic safety of the SM. We account fo ...

We study localization of bulk fermions on a brane with inclusion of Yang-Mills and scalar backgrounds in higher dimensions and give the conditions under which localized chiral fermions can be obtained. (C) 2000 Elsevier Science B.V.

We study a finite, divergence-free approach to renormalisation originally proposed in the early '70s by Blaer and Young, and Callan. It is based on equations similar to the Callan-Symanzik equations and introduced in the context of the & lambda;& phi;4 the ...

Low-scale leptogenesis provides an economic and testable description of the origin of the baryon asymmetry of the Universe. In this scenario, the baryon asymmetry of the Universe is reprocessed from the lepton asymmetry by electroweak sphaleron processes. ...

The Search for Hidden Particles (SHiP) Collaboration has shown that the CERN SPS accelerator with its 400 GeV/c proton beam offers a unique opportunity to explore the Hidden Sector [1-3]. The proposed experiment is an intensity frontier experiment which is ...

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 ...

In this paper we examine the 4-dimensional effective theory for the light Kaluza-Klein (KK) modes. Our main interest is in the interaction terms. We point out that the contribution of the heavy KK modes is generally needed in order to reproduce the correct ...

In response to the 2013 Update of the European Strategy for Particle Physics, the Future Circular Collider (FCC) study was launched, as an international collaboration hosted by CERN. This study covers a highest-luminosity high-energy lepton collider (FCC-e ...

Mikhail Chapochnikov

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

Observation of Collider Neutrinos without Final State Muons with the SND@LHC Experiment

The nuMSM, dark matter and neutrino masses

DETERMINATION OF g (omega rho pi) CONSTANT FROM QCD SUM RULES

Supersymmetric dark matter Q-balls and their interactions in matter

Can an odd number of fermions be created due to chiral anomaly?

Sensitivity of the SHiP experiment to light dark matter

Asymptotic safety of gravity and the Higgs-boson mass

Why should we care about the top quark Yukawa coupling?

Polarization of photons emitted by decaying dark matter

Sufficient conditions for the existence of Q-balls in gauge theories

Baryon asymmetry of the universe in the minimal Standard Model

Higgs boson mass and new physics

Fermion zero-modes on brane-worlds

Finite Callan-Symanzik renormalisation for multiple scalar fields

Freeze-out of baryon number in low-scale leptogenesis

The experimental facility for the Search for Hidden Particles at the CERN SPS

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

On the decoupling of heavy modes in Kaluza-Klein theories

FCC-ee: The Lepton Collider: Future Circular Collider Conceptual Design Report Volume 2