Conveners
Section 5. Neutrino physics and astrophysics
- Egor Zemlin (Saint Petersburg State University, Russia)
Section 5. Neutrino physics and astrophysics
- Tatiana Lazareva (St Petersburg State University (RU))
Effect of inelastic nuclear scattering in magnetized hot and dense matter in neutrino spectra relevant for supernovae, neutron star mergers, proto-neutron stars is considered. At finite temperature neutrino exhibits exo- and endoenergetic scattering on nuclear species due to the neutral-current Gamow-Teller interaction component. The kinetic equation for neutrino transport at decoupling regime...
The observed excess of electronic recoil events in the XENON1T experiment with energies from 1 to 7 keV [1] is considered in the framework of the phenomenological model with three active and three sterile neutrinos [2]. Assuming sterile neutrinos with appropriate masses in the several keVs domain to be decaying [3], it becomes possible to interpret the observed energy spectrum of electronic...
The process of double neutrinoless e-capture is of great interest as a test of the Majorana nature of neutrino This process is traditionally considered as a resonance one, since not a single particle is emitted as a result of the nuclear transformation [1]. In contrast, we performed calculations of the probability of shake off and shake up, with the ionization or excitation of the electron...
The work presents calculations of the solar neutrino capture cross-section σ(Eν) by 100Mo nuclei. In calculations experimental data on strength function S(E), received in charge-exchange reactions (3He, t) [1, 2] were used. Within the framework of the self-consistent theory of finite Fermi systems, the charge-exchange strength function S(E) for this nucleus is calculated. The influence of the...
I.N. Borzov 1,2
1 National Research Centre “Kurchatov Institute”, 123182, Moscow, Russia
2Bogolubov Laboratory of Theoretical Physics, Joint Institute of Nuclear Research, 141980,
†E-mail: Borzov_IN@nrcki.ru, cc: ibor48@mail.ru
The first direct detection of the neutrinos from carbon-nitrogen-oxygen (CNO) fusion cycle in the Sun has been announced recently by the BOREXINO Collaboration [1]....
The discovery of neutron star merger process and simultaneous observation of heavy elements registered for the first time [1] confirms the theoretical findings that neutron star merger scenario for the close binary is the main site for the r-process passing.
As it was shown for the first time in numerical calculations of the r-process [2], the fission in such a scenario became one of the...
Neutrino capture cross-section, which depend on the incident-neutrino energy $E_{\nu}$, has the form:
$\sigma(E_{\nu}) = \frac{(G_F g_A)^2}{\pi c^3 \hbar^4} \int_{0}^{W - Q} W p_e F(Z, A, W) S(x) dx$
where $S(E)$ is the charge-exchange strength function, $G_F / (\hbar c)^3 = 1.1663787(6) \times 10^{-5}$ $GeV^{-2}$ is the weak coupling constant, $g_A = - 1.2723$ is the axial-vector constant...
More than the half of all nuclei heavier iron in nature are formed in the nucleosynthesis, supported by rapid neutron capture process, and the region where it has occurred lies close to neutron drip-line [1]. The nucleosynthesis rate of heavy nuclei in the r-process is defined both by the astrophysical scenario and beta-decay rates of heavy nuclei involved. Under speeding up or slowing down...
Future liquid-argon DarkSide-20k and ARGO detectors, designed for direct
dark matter search, will be sensitive also to core-collapse supernova
neutrinos, via coherent elastic neutrino-nucleus scattering.
Thanks to the low-energy threshold of ∼0.5~keVnr achievable via the
ionization channel, DarkSide-20k and ARGO have the potential to discover
supernova bursts throughout our galaxy and up...
Search for heavy sterile neutrinos in $\beta$-decay of $^{144}$Pr nuclei.
A.V. Derbin, I.S. Drachnev, A.M. Kuzmichev, I.S Lomskaya, M.S. Mikulich,
V.N. Muratova, N.V. Niyazova, D.A. Semenov, M.V. Trushin, E.V. Unzhakov
Petersburg Nuclear Physics Institute of NRC Kurchatov Institute, 188309 Gatchina, Russia
The discovery of solar and atmospheric neutrino oscillations means that at...
Monte Carlo simulation of the multi-section reactor antineutrino detector of the Neutrino-4 experiment is carried out. The scintillation-type detector is based on the inverse beta-decay reaction. The current experiment at the SM-3 reactor (Dimitrovgrad, Russia) and the future experiment at the PIK reactor (Gatchina, Russia) are considered. As a result of the simulation, the distributions of...
The Neutrino-4 collaboration plans to improve existing detector and to create new neutrino laboratory at reactor SM-3.
Equipment for the new neutrino laboratory at the SM-3 reactor is being prepared for implementation. Main part of the improving is new scintillator with higher gadolinium concentration and doped with DIN for pulse shape discrimination ability increase. Thus, a new detector...
An advance in solution of the sterile neutrino search can be reached by creation of the intensive $\bar \nu{_e}$-source with well known hard spectrum. The most intensive artificial antineutrino sources used for neutrino experiments are the nuclear reactors. The resulting reactor $\bar \nu{_e}$-flux is the complicated additive function of fluxes: from fission fragments; from $\beta $-decay...
Results of NEMO-3 experiment for double beta decay of $^{150}$Nd to the 0$^+_1$ and 2$^+_1$ excited states of $^{150}$Sm are reported. The data recorded during 5.25 y with 36.6 g of the isotope $^{150}$Nd was used in the analysis. For the first time the signal of 2νββ transition to the $0^+_1$ excited state is detected with statistical significance exceeding 5 sigma. The half-life is measured...
Borexino is a large liquid scintillator experiment designed for real-time detection of low-energy solar neutrinos. It is located at the underground INFN Laboratori Nazionali del Gran Sasso, in Italy. During more than ten years of data collection, it has measured all the neutrino fluxes produced in the proton-proton-chain, i.e. the main fusion process accounting for ~99% of the energy...
Neutrinos are probably the most mysterious particles of the Standard Model. The mass hierarchy and oscillations, as well as the nature of their antiparticles, are currently being studied in experiments around the world. Moreover, in many models of the New Physics, baryon asymmetry or dark matter density in the universe are explained by introducing new species of neutrinos. Among others, heavy...
The work evaluates the background induced by solar neutrinos into the experiment GERDA, that was organized to search for neutrinoless double beta decay of Ge-76 nucleus. A feature of this background is its fundamental inevitability, which imposes restrictions on the sensitivity of the entire experimental setup. To calculate the cross section for the solar neutrinos capture by Ge-76 nuclei, the...
While the field of nuclear astrophysics has recently been a burgeoning area of study and research, there is still a significant portion of information regarding the topic that is not known to science. In particular, while certain foundations of the subject area seem plausible, there is not currently any proof that helium fusion is a key component that drives nuclear astrophysics. In this work,...
