[f(k)] Fwd: Physics Qolloquium 3.12.

[Puheenjohtaja F(k)]

Hi all,

The next colloquium will be TOMORROW starting at 10:00 in FYS1.
Further information below.

- Samuli

-------- Alkuperäinen viesti --------
 From: tuomas.grahn at jyu.fi
When: 10.00 - 11.30 3. December 2025
Subject: Physics Colloquium 3.12.
Location: FYS1 YFL230 FYS1 (Fysiikan laitosrakennus)

Welcome to the Physics Colloquium on Wed 3 December at 10:00 in FYS1

Note the unusual time!

We will start with coffee at 10:00 and with presentation at 10:15.

Neutrino masses, mixing, oscillations, 0nbb-decay, and nuclear
structure

Fedor Šimkovic

Comenius University of Bratislava

A new method for formulating a quantum field theory of neutrino
oscillations has been proposed, focusing on the charged-current vertices
of a second-order Feynman diagram that includes neutrino emission,
detection, and propagation. A master formula for the rate of
charged-lepton production as a function of distance L has been derived,
also predicting the production rate of the Racah process, in which
neutrinos oscillate into antineutrinos. This research links Majorana
neutrino masses—vital for understanding neutrinoless double-beta
decay—with neutrino-antineutrino oscillations. Investigating Racah's
process may help identify the Majorana nature of neutrinos. New
techniques for constructing process amplitudes using the neutrino mass
matrix, bypassing the mixing matrix via Sylvester's theorem and
Frobenius covariants, are introduced. Fitting experimental data to the
mass matrix could yield more accurate statistical results. Additionally,
a mechanism for generating Majorana neutrino mass due to chiral symmetry
breaking and quark condensate formation is presented. Simplified
scenarios within left-right symmetric models with quasi-Dirac neutrinos
are discussed, along with new modes of double-beta decay and current
calculations of nuclear-matrix elements. The effects of quenching the
axial-vector coupling constant on double-beta decay processes and
related studies of beta decay, two-neutrino beta-beta decay, muon
capture, and double-charge exchange nuclear reactions are also examined.