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Ionel Lazanu

Publications and source records attributed to Ionel Lazanu.

At least 19 recordsLinked to original sources
arXiv2026

A New Way to Detect Axions from $\rm{A\bar{Q}Ns}$ Captured in the Earth

Macroscopic dark matter with dominating strong interactions, supposed to be composites, represents an alternative to the most popular WIMP particles. Predicted in various models as strangelets, nuclearites, nuggets, having different internal structures and properties, but not yet observed experimentally, these forms of dark matter are associated with the existence of a large number of still unexplained observations. Nuggets, initially predicted by Witten, were reconsidered from the point of view of their internal structure and further theorized in 2003 by Zhitnitsky as axion quark nuggets and axion antiquark nuggets, as being made of quarks in a superconducting colour state, in the core, an electrosphere of electrons or positrons and a domain wall that maintain the stability of the macros with an incredible density, mass in the gram range and radius on the order of micrometers. If the existence of $\rm{AQNs}$ and $\rm{A\bar{Q}Ns}$ is demonstrated, two major open problems in physics could be addressed simultaneously: they would constitute viable dark matter candidates and, at the same time, provide a natural mechanism for restoring matter-antimatter symmetry in the Universe. The experimental evidence of the $\rm{AQNs}$ and $\rm{A\bar{Q}Ns}$ is a challenge for current and future experiments. The present study demonstrates that if these macroscopic systems exist, axions produced by $\rm{A\bar{Q}N}$s could be detected by the next generation of neutrino physics experiments using liquid noble gases, due to their huge active volumes.

hep-ph↗
arXiv2025

Nuclear effects in proton decay

Proton decay detection could put in evidence physics beyond the Standard Model (BSM). In this context, multiple projects are searching for such events. We focused our work on two of the expected decay modes, $p \rightarrow \pi^+ + \bar{\nu}$ and $p \rightarrow K^+ + \bar{\nu}$. Neutrinos are particles that interact very weakly with matter, so they are not of interest in our work. The detector materials investigated in this study include liquid argon (LAr), liquid xenon (LXe), and water (H$_2$O). Our analysis focuses on two key effects relevant to this decay process: the Fermi motion of nucleons and final state interactions. In addition to these effects, we have also examined the nuclear interaction of particles with the nuclei of the medium. This paper presents values for nucleon energy distribution, cross sections, mean free paths and interaction probabilities.

hep-ph↗
arXiv2024

A new possible way to detect Axion Anti-quark Nuggets

The axion anti-quark nugget (A$\bar{\mathrm{Q}}$N) model was developed to explain in a natural way the asymmetry between matter and antimatter in Universe. In this hypothesis, a similitude between the dark and the visible components exists. The lack of observability of any type of dark matter up to now, in particular A$\bar{\mathrm{Q}}$Ns, requires finding new ways of detecting these particles, if they exist. In spite of strong interaction with visible matter, for such objects a very small ratio of cross section to mass is expected and thus huge detector systems are necessary. This paper presents a new idea for the direct detection of the A$\bar{\mathrm{Q}}$Ns using minerals as natural rock deposits acting as paleo-detectors, where the latent signals of luminescence produced by interactions of A$\bar{\mathrm{Q}}$Ns are registered and can be identified as an increased and symmetrical deposited dose. The estimates were made for minerals widely distributed on Earth, for which the TL signal is intense and if the thermal conditions are constant and with low temperatures, the lifetime of the latent signals is kept for geological time scales.

hep-ph↗
arXiv2024

Exploring the detection of AQNs in large liquid detectors

Recent work from the last years has raised the possibility that a portion of Dark Matter could consist of exotic particles, such as axion (anti)quark nuggets (AQN, A\bar{Q}N). After a brief review outlining the main features of axion antiquark nuggets, we explore potential experimental signatures that can be leveraged to search for these stable supermassive particles in future surface and underground experiments using large liquid detectors. These expected signals are discussed in relation to the specific characteristics of each detection system.

hep-ph↗
arXiv2021

Can strangelets be detected in a large LAr neutrino detector?

Predicted as possible bound states of up, down and strange quarks, strangelets could be more energetically favourable and more stable than nuclear matter. In this paper we explore the possibility of detecting such particles with the future large liquid argon detectors developed for neutrino physics. Using signals from ionization and scintillations we suggest that a calorimetric TCP detector is able to put in evidence and to discriminate between light strangelets at intermediate energy.

physics.ins-det↗
arXiv2021

Radioactive background for ProtoDUNE detector

The Deep Underground Neutrino Experiment (DUNE) is a leading-edge, international experiment for neutrino science and proton decay studies. This experiment is looking for answers regarding several fundamental questions about the nature of matter and the evolution of the universe: origin of matter, unification of forces, physics of black holes. Two far detector prototypes using two distinct technologies have been developed at CERN. The prototypes are testing and validating the liquid argon time projection chamber technology (LArTPC). In neutrino physics, as well as in any experiment with rare interaction rate, the good knowledge of the radioactive backgrounds is important to the success of the study. Unlike most of the charged particles or short lived neutral particles, muons and neutrons represent the main sources of background for this kind of experiments. In this paper, we have considered two sources of neutrons: cosmic neutrons and neutrons coming from the accelerating tunnel. Also, cosmic muons are taken into account. The contribution of these particles to the production of radioactive isotopes inside the active volume of the detector in comparison to the one corresponding to muons is shown. Also, simulations of nuclear reactions for the processes of interest for investigating the radioactive background due to the lack of measurements or insufficient experimental data are presented. The results presented are of interest for the future underground DUNE experiment.

physics.ins-det↗
arXiv2020

About detecting very low mass black holes in LAr detectors

The nature of dark matter is still an open problem. The simplest assumption is that gravity is the only force coupled certainly to dark matter and thus the micro black holes could be a viable candidate. We investigated the possibility of direct detection of micro black holes with masses around and upward the Planck scale (10$^{-5}$ g), ensuring classical gravitational treatment of these objects in the next generation of huge LAr detectors. We show that the signals (ionization and scintillation) produced in LAr enable the discrimination between micro black holes or other particles. It is expected that the trajectories of these micro black holes will appear as crossing the whole active medium, in any direction, producing uniform ionization and scintillation on all the path.

hep-ph↗
arXiv2017

Measurement of low energy component of the flux of cosmic rays using nuclear track detectors

The effects induced by muons with very low energies are usually neglected. In fact, they could represent a source of radioactive background due to capture processes in different materials, which in most of cases produce radioactive isotopes, and thus they must be taken into account. Plastic track detectors have been used in the present paper to measure the ratio between the vertical and horizontal components of the flux of very low energy terrestrial muons at ground level. The data have been collected during 160 days.

physics.ins-det↗
arXiv2015

Contribution of the electron-phonon interaction to Lindhard energy partition at low energy in Ge and Si detectors for astroparticle physics applications

The influence of the transient thermal effects on the partition of the energy of selfrecoils in germanium and silicon into energy eventually given to electrons and to atomic recoils respectively is studied. The transient effects are treated in the frame of the thermal spike model, which considers the electronic and atomic subsystems coupled through the electron - phonon interaction. For low energies of selfrecoils, we show that the corrections to the energy partition curves due to the energy exchange during the transient processes modify the Lindhard predictions. These effects depend on the initial temperature of the target material, as the energies exchanged between electronic and lattice subsystems have different signs for temperatures lower and higher than about 15 K. Many of the experimental data reported in the literature support the model.

astro-ph.IM↗
arXiv2013

Analysis of defect formation in semiconductor cryogenic bolometric detectors created by heavy dark matter

The cryogenic detectors in the form of bolometers are presently used for different applications, in particular for very rare or hypothetical events associated with new forms of matter, specifically related to the existence of Dark Matter. In the detection of particles with a semiconductor as target and detector, usually two signals are measured: ionization and heat. The amplification of the thermal signal is obtained with the prescriptions from Luke-Neganov effect. The energy deposited in the semiconductor lattice as stable defects in the form of Frenkel pairs at cryogenic temperatures, following the interaction of a dark matter particle, is evaluated and consequences for measured quantities are discussed. This contribution is included in the energy balance of the Luke effect. Applying the present model to germanium and silicon, we found that for the same incident weakly interacting massive particle the energy deposited in defects in germanium is about twice the value for silicon.

astro-ph.IM↗
arXiv2012

The next-generation liquid-scintillator neutrino observatory LENA

We propose the liquid-scintillator detector LENA (Low Energy Neutrino Astronomy) as a next-generation neutrino observatory on the scale of 50 kt. The outstanding successes of the Borexino and KamLAND experiments demonstrate the large potential of liquid-scintillator detectors in low-energy neutrino physics. LENA's physics objectives comprise the observation of astrophysical and terrestrial neutrino sources as well as the investigation of neutrino oscillations. In the GeV energy range, the search for proton decay and long-baseline neutrino oscillation experiments complement the low-energy program. Based on the considerable expertise present in European and international research groups, the technical design is sufficiently mature to allow for an early start of detector realization.

astro-ph.IM↗
arXiv2011

Transient thermal effects in solid noble gases as materials for the detection of Dark Matter

The transient phenomena produced in solid noble gases by the stopping of the recoils resulting from the elastic scattering processes of WIMPs from the galactic halo were modelled, as dependencies of the temperatures of lattice and electronic subsystems on the distance to the recoil's trajectory, and time from its passage. The peculiarities of these thermal transients produced in Ar, Kr and Xe were analysed for different initial temperatures and WIMP energies, and were correlated with the characteristics of the targets and with the energy loss of the recoils. The results were compared with the thermal spikes produced by the same WIMPs in Si and Ge. In the range of the energy of interest, up to tens of keV for the self-recoil, local phase transitions solid - liquid and even liquid - gas were found possible, and the threshold parameters were established.

astro-ph.IM↗
arXiv2011

A mobile detector for measurements of the atmospheric muon flux in underground sites

Muons comprise an important contribution of the natural radiation dose in air (approx. 30 nSv/h of a total dose rate of 65-130 nSv/h), as well as in underground sites even when the flux and relative contribution are significantly reduced. The flux of the muons observed in underground can be used as an estimator for the depth in mwe (meter water equivalent) of the underground site. The water equivalent depth is an important information to devise physics experiments feasible for a specific site. A mobile detector for performing measurements of the muon's flux was developed in IFIN-HH, Bucharest. Consisting of 2 scintillator plates (approx. 0.9 m2) which measure in coincidence, the detector is installed on a van which facilitates measurements at different locations at surface or underground. The detector was used to determine muon fluxes at different sites in Romania. In particular, data were taken and the values of meter water equivalents were assessed for several locations from the salt mine from Slanic Prahova, Romania. The measurements have been performed in 2 different galleries of the Slanic mine at different depths. In order to test the stability of the method, also measure- ments of the muon flux at surface at different elevations were performed. The results were compared with predictions of Monte-Carlo simulations using the CORSIKA and MUSIC codes.

astro-ph.IM↗
arXiv2010

Modelling the transient processes produced under heavy particle irradiation

A new model for the thermal spike produced by the nuclear energy loss, as source of transient processes, is derived analytically, for power law dependences of the diffusivity on temperature, as solution of the heat equation. The contribution of the ionizing energy loss to the spike is not included. The range of validity of the model is analysed, and the results are compared with numerical solutions obtained in the frame of the previous model of the authors, which takes into account both nuclear and ionization energy losses, as well as the coupling between the two subsystems in crystalline semiconductors. Particular solutions are discussed and the errors induced by these approximations are analysed.

physics.ins-det↗
arXiv2010

Gif Lectures on direct detection of Dark Matter

These notes cover some of the topics associated with direct detection of dark matter at an introductory level. The general principles of dark matter search are summarized. The current status of some experiments is described, with an emphasis on bolometric and noble liquid techniques. Plots and illustrations associated to these notes may be found on transparencies presented during the lecture, on the web site of Gif school 2009.

hep-ex↗
arXiv2009

Short remarks on possible production of defects in low temperature semiconductor detectors for dark matter physics experiments

The nature of dark matter is still an open problem, but there is evidence that a large part of the dark matter in the universe is non-baryonic, non-luminous and non-relativistic and hypothetical Weakly Interacting Massive Particles (WIMPs) are candidates that satisfy all of the above criteria. In order to minimize the ambiguities in the identification of WIMPs' interactions in their search, in more experiments, two distinct quantities are simultaneously measured: the ionization and phonon or light from scintillation signals. Silicon and germanium crystals are used in some experiments. In this paper we discuss the production of defects in semiconductors due to WIMP interactions and estimate their contribution in the energy balance. This phenomenon is present at all temperatures, is important in the range of keV energies, but is not taken into consideration in the usual analysis of experimental signals and could introduce errors in identification for WIMPs.

physics.ins-det↗
arXiv2006

Modelling spatial distribution of defects and estimation of electrical degradation of silicon detectors in radiation fields at high luminosity

The irradiation represents a useful tool for determining the characteristics of defects in semiconductors as well as a method to evaluate their degradation, fact with important technological consequences. In this contribution, starting from available data on the degradation of silicon detector characteristics in radiation fields, these effects are explained in the frame of a model that supposes also the production of the SiFFCD defect due to irradiation. The displacement threshold energies - different for different crystallographic axes, considered as parameters of the model, are established and the results obtained could contribute to clarify these controversial aspects. Predictions of the degradation of electrical parameters (leakage current, effective carrier concentration and effective trapping probabilities for electrons and holes) of DOFZ silicon detectors in the hadron background of the LHC accelerator, supposing operation at -10 grdC are done. The non uniformity of the rate of production of primary defects and of complexes, as a function of depth, for incident particles with low kinetic energy was obtained by simulations in some particular and very simplifying assumptions, suggesting the possible important contribution of the low energy component of the background spectra to detector degradation.

physics.ins-det↗