Publications by Mikhail Chapochnikov

Installation and performance of the 3rd Veto plane at the SND@LHC detector

Lesya Shchutska, Olivier Schneider, Aurelio Bay, Konstantin Androsov, Jan Steggemann, Elena Graverini, Ettore Zaffaroni, Mikhail Chapochnikov, Anna Mascellani, Carina Trippl

During 2022/2023 the optimal inefficiency of the Veto system of the SND@LHC detector was measured to be (7.8 ± 2.8) × 10−8. To reduce this inefficiency, a third Veto plane was installed during the 2023-2024 Year End Technical Stop. In addition, the Veto sy ...

2025

Nonrenormalizable theories and finite formulation of QFT

Mikhail Chapochnikov

In this paper, we show how the finite formulation of quantum field theory based on Callan-Symanzik equations can be generalized to the case of nonrenormalizable theories. We derive an equation for effective action for an arbitrary single scalar field theor ...

AMER PHYSICAL SOC2025

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

Lesya Shchutska, Olivier Schneider, Aurelio Bay, Konstantin Androsov, Jan Steggemann, Elena Graverini, Ettore Zaffaroni, Mikhail Chapochnikov, Zhenyu Yang, Anna Mascellani

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 ...

American Physical Society (APS)2025

Sterile neutrinos as dark matter

Mikhail Chapochnikov

I describe the sterile neutrino dark matter candidate and discuss how it may fit into the overall picture of physics beyond the Standard Model. ...

Elsevier2024

Cosmic Matter-Antimatter Separation and Sterile Neutrino Dark Matter

Mikhail Chapochnikov

The lattice studies provided evidence of a smooth crossover between the hadronic and quark-gluon phases at high temperatures and zero chemical potential for baryonic number. We argue that these simulations may not rule out relatively weekly first-order pha ...

Sissa Medialab Srl2024

Sterile neutrino dark matter, matter-antimatter separation, and the QCD phase transition

Mikhail Chapochnikov

The Universe may contain sufficiently small size matter-antimatter domains at temperatures of a few hundred MeV, without violating the success of big bang nucleosynthesis. We demonstrate that this possibility enhances the keV scale sterile neutrino product ...

American Physical Society2024

Measurement of the muon flux at the SND@LHC experiment

Lesya Shchutska, Olivier Schneider, Aurelio Bay, Guido Haefeli, Elena Graverini, Ettore Zaffaroni, Mikhail Chapochnikov, Anna Mascellani, Carina Trippl, Serhii Cholak

The Scattering and Neutrino Detector at the LHC (SND@LHC) started taking data at the beginning of Run 3 of the LHC. The experiment is designed to perform measurements with neutrinos produced in proton-proton collisions at the LHC in an energy range between ...

2024

Results and Perspectives from the First Two Years of Neutrino Physics at the LHC by the SND@LHC Experiment

Lesya Shchutska, Olivier Schneider, Aurelio Bay, Konstantin Androsov, Jan Steggemann, Guido Haefeli, Elena Graverini, Ettore Zaffaroni, Mikhail Chapochnikov, Sun Hee Kim

After rapid approval and installation, the SND@LHC Collaboration was able to gather data successfully in 2022 and 2023. Neutrino interactions from nu(mu)s originating at the LHC IP1 were observed. Since muons constitute the major background for neutrino in ...

MDPI2024

Reconstruction of 400 GeV/c proton interactions with the SHiP-charm project

Lesya Shchutska, Elena Graverini, Mikhail Chapochnikov, Federico Leo Redi, Maria Elena Stramaglia, Inar Timiryasov, Alexandre Emmanuel Grandchamp, Ana Bárbara Rodrigues Cavalcante

The SHiP-charm project was proposed to measure the associated charm production induced by 400 GeV/c protons in a thick target, including the contribution from cascade production. An optimisation run was performed in July 2018 at CERN SPS using a hybrid set ...

2024

Weyl-invariant Einstein-Cartan gravity: unifying the strong CP and hierarchy puzzles

Mikhail Chapochnikov

We show that the minimal Weyl-invariant Einstein-Cartan gravity in combination with the Standard Model of particle physics contains just one extra scalar degree of freedom (in addition to the graviton and the Standard Model fields) with the properties of a ...

Springer Nature2024