Decay Of Nuclei Research Articles

Evaluation of the Histological Changes as Effect of Type 2 Diabetic Mellitus on the Oral Epithelium (Buccal Mucosa and Gingiva)

Background: Exfoliative cytology considered as one of the best technique to obtain the epithelial cells lining buccal mucosa in oral cavity. Diabetes mellitus type 2 is one of the most distributed disorder wild world which cause deferent histological and cytological defects in all body organs. Aim: To realize the histological changes in oral epithelium (of buccal and gingival mucosa) in patients suffering from type 2 diabetic mellitus. Material and methods: Sample composed of two groups, the study group represented by ten male diabetic patients, their age between (50-65) years attending the teaching hospital of college of Dentistry/ Tikrit university, and the control group (10 male 50-65 years old), the smear taken from oral epithelia from buccal mucosa, gingiva and saliva using cotton swab. The samples were carried on glass slides and stained by using Giemsa dye.Results: The microscopical examination revealed a number of histological changes, as presence of binucleated cells, budding in nuclei and decay (karyolysis) of other nuclei with the observation of fragmentation (karyorrhexis) of others, besides, some of vasicular degeneration seen with the cytoplasm of number of cells and hypertrophy in others.Conclusion: Diabetes mellitus type 2 cause many histological changes in oral epithelia of buccal mucosa and gingiva which detected by exfoliative cytology.

Enabling kilonova science with Nancy Grace Roman Space Telescope

Binary neutron star mergers and neutron star–black hole mergers are multi-messenger sources that can be detected in gravitational waves and in electromagnetic radiation. The low electron fraction of neutron star merger ejecta favors the production of heavy elements such as lanthanides and actinides via rapid neutron capture (r-process). The decay of these unstable nuclei powers an infrared-bright transient called a “kilonova”. The discovery of a population of kilonovae will allow us to determine if neutron star mergers are the dominant sites for r-process element nucleosynthesis, constrain the equation of state of nuclear matter, and make independent measurements of the Hubble constant. The Nancy Grace Roman Space Telescope (Roman) will have a unique combination of depth, near-infrared sensitivity, and wide field of view. These characteristics will enable Roman’s discovery of GW counterparts that will be missed by optical telescopes, such as kilonova that are associated with large distances, high lanthanide fractions, high binary mass-ratios, large dust extinction in the line of sight, or that are observed from equatorial viewing angles. In preparation for Roman’s launch and operations, our analysis suggests to (i) make available a rapid (∼1 week) Target of Opportunity mode for GW follow-up; (ii) include observations of the High Latitude Time-Domain survey footprint in at least two filters (preferably the F158 and F213 filters) with a cadence of ≲8 days; (iii) operate in synergy with Rubin Observatory. Following these recommendations, we expect that 1–6 kilonovae can be identified by Roman via target of opportunity observations of well localized (A<10deg2, 90% C.I.) neutron star mergers during 1.5 years of the LIGO-Virgo-KAGRA fifth (or ∼4–21 in during the sixth) observing run. A sample of 5–40 serendipitously discovered kilonovae can be collected in a 5-year high latitude survey.

Probing the Dark Sector with Nuclear Transition Photons.

Here we present world-leading sensitivity to light (<170 MeV) dark matter (DM) using beam-dump experiments. Dark sector particles produced during pion decay at accelerator beam dumps can be detected via scattering in neutrino detectors. The decay of nuclei excited by the inelastic scattering of DM is an unexploited channel which has significantly better sensitivity than similar searches using the elastic scattering channel. We show that this channel is a powerful probe of DM by demonstrating sensitivity to the thermal relic abundance benchmark in a scalar DM dark-photon portal model. This is achieved through the use of existing data, obtained by the KARMEN experiment over two decades ago, which allow us to set world-leading constraints on this model over a wide mass range. With experimental improvements planned for the future, this technique will be able to probe the thermal relic benchmark for fermionic DM across a wide mass range.

The parameter-free Monte Carlo approach for diffractive dissociation of relativistic oxygen nuclei into four alpha particles in interactions with protons at 3.25GeV/c per nucleon

In this paper, we have investigated the processes of formation of four alpha particles in the final state in the reactions [Formula: see text] of diffractive dissociation of oxygen-16 nuclei in interactions with protons at an incident momentum of 3.25[Formula: see text]GeV/[Formula: see text] per nucleon. A Monte Carlo model is proposed to describe the kinematic characteristics of the produced alpha particles. The proposed Monte Carlo model does not have any free parameters. The algorithm of the model takes into account the energetically allowed channels of direct (or cascade) decays of the excited oxygen-16 nuclei into the final four alpha particles. To form the masses of the excited oxygen-16, carbon-12, and beryllium-8 nuclei, the experimental tables of their excitation levels have been used. All decays have been generated isotropically in the rest frame of each unstable nucleus — the excited oxygen-16, carbon-12, and beryllium-8 nuclei. The results of the Monte Carlo model calculations have proved to be in good agreement with distributions of various kinematic characteristics of the final state alpha particles taken from the experiment. The good agreement is reached if, after simulation of the mass of the excited oxygen-16, the energetically allowed decay channel is selected for which the sum of the total energy, released in this channel, and the masses of the four secondary alpha particles turn out to be less, but closest to the mass of the excited oxygen-16 nucleus. At a high level of excitation, there are several channels with the same energy release, which have been generated with equal probabilities.

Systematic investigation of the alpha and cluster decay half-lives for heavy and superheavy nuclei within the shifted Deng-Fan potential

The half-lives of alpha decays for even-even nuclei with Z=60−118 and the cluster radioactivities for even-even emitters for which the experimental data are available, also the various cluster decays of even-even radium isotopes are calculated. Our calculations are within the framework of Wentzel-Kramers-Brillouin (WKB) method by considering the Bohr-Sommerfeld quantization condition based on the shifted Deng-Fan potential. The obtained results are compared with the squared Woods-Saxon and Cosh potentials and several theoretical models, including the universal model (UNIV), the unified fission model (UFM), the universal decay law (UDL), and Ni, Royer, Tavares and Balasubramaniam semiempirical formulas, as well as the experimental data. Good agreement between the experimental and the proposed potential model results, indicates that the shifted Deng-Fan potential is a suitable phenomenological potential to describe both alpha and cluster decays of radioactive nuclei. Also we observe the significant role of neutron magicity in the half-lives of cluster decays of radium isotopes at N=126 of daughter nuclei and the parent nucleus 214Ra.

Alpha decay and cluster radioactivity investigation of actinide nuclei

Based on the Unified Fission Model with a Woods–Saxon potential (UFMWS), we have investigated alpha decay and cluster radioactivity of actinide nuclei. To ensure accuracy, we determined the most precise [Formula: see text]-values by comparing the results of four nuclear mass models: the liquid drop model (LDM), the DZ28 model, the WS4 model, and the finite range droplet model (FRDM), which were recently improved using a machine learning algorithm. Among these models, it is found that the improved WS4 (IWS4) provides the most accurate [Formula: see text]-values, enabling the UFMWS model to effectively reproduce experimental alpha and cluster decay half-lives. Consequently, the UFMWS model using IWS4 [Formula: see text]-values was employed to explore various combinations of parent nuclei and alpha particle as well as even–even emitted clusters ranging from Be to Si. The obtained results are consistent with previous study that identified minima in half-lives near corresponding to the doubly magic [Formula: see text]Pb daughter nucleus or its neighboring nuclei. It is found that neutron-deficient parent nuclei generally displayed the shortest half-lives, most of which are within the experimental range. Considering the experimental limitations, cluster decays favorable for measurement in the actinide region were identified. Interestingly, these decays did not involve the most neutron-deficient nuclei.

Reflective Thinking Profile of Physics Teacher Prospective Students through Nuclear Physics Learning using Virtual Laboratory

Virtual Laboratory is a platform that helps students carry out practicum-based learning both independently and in groups. Nuclear physics is an abstract concept that discusses atomic nuclei, atomic nuclei decay, radioactivity which allows in practice to use virtual. The purpose of this study was to determine the level of students' reflective thinking skills after using the virtual lab in the nuclear physics course. The method used is descriptive quantitative. The data collection technique used a modified Kember reflective questionnaire with 24 statement items consisting of aspects of habitual action, understanding, reflection, and critical reflection. The research subjects were 15 prospective physics teacher students. The results showed that the level of reflective ability: habitual action (72.7%), understanding (89.3%), reflection 76.9% and critical reflection (67.87%) means that all levels are in the high category. These results explain that the profile of students' reflective thinking abilities is in the high category after learning nuclear physics using a virtual laboratory.

Opacities of singly and doubly ionized neodymium and uranium for kilonova emission modeling

ABSTRACT Even though the electromagnetic counterpart AT2017gfo to the binary neutron star merger GW170817 is powered by the radioactive decay of r-process nuclei, only few tentative identifications of light r-process elements have been made so far. One of the major limitations for the identification of heavy nuclei is incomplete or missing atomic data. While substantial progress has been made on lanthanide atomic data over the last few years, for actinides there has been less emphasis, with the first complete set of opacity data only recently published. We perform atomic structure calculations of neodymium (Z = 60) as well as the corresponding actinide uranium (Z = 92). Using two different codes [flexible atomic code (fac) and hartree–fock-relativistic (hfr)] for the calculation of the atomic data, we investigate the accuracy of the calculated data (energy levels and electric dipole transitions) and their effect on kilonova opacities. For the fac calculations, we optimize the local central potential and the number of included configurations and use a dedicated calibration technique to improve the agreement between theoretical and available experimental atomic energy levels (AELs). For ions with vast amounts of experimental data available, the presented opacities agree quite well with previous estimations. On the other hand, the optimization and calibration method cannot be used for ions with only few available AELs. For these cases, where no experimental nor benchmarked calculations are available, a large spread in the opacities estimated from the atomic data obtained with the various atomic structure codes is observed. We find that the opacity of uranium is almost double the neodymium opacity.

Weak decay of halo nuclei

Weak decay of halo nuclei

Influence of Geant4 physics list on simulation accuracy and performance

A main goal of current low background physics is the search for rare and novel phenomena beyond the Standard Model of particle physics, e.g. the scattering off of a potential Dark Matter particle inside a CaWO_44 crystal or the neutrinoless double beta decay of Ge nucleus. The success of such searches depends on a reliable background prediction via Monte Carlo simulations. A widely used toolkit to construct these simulations is GEANT4, which offers a wide choice of physics models, so-called physics lists. To facilitate the selection of physics lists for simulations of CaWO_44 and Ge targets, we quantify their impact on the total energy deposition for several test cases.

EFECTO DE LA RENORMALIZACIÓN DEL FACTOR ESPECTROSCÓPICO EN EL DECAMIENTO DEL 212Po

In the present work, we use the complex-energy shell model formalism to describe the alpha decay of the 212Po nucleus. Single-particle bases constructed from Woods-Saxon potentials are used to build many-body basis. Spin-isospinGaussian effective interaction between all pairs of nucleons is considered. Four-body spectroscopic factor and single-particle width are calculated. The stability of the spectroscopic factor renormalization protocol is demonstrated, thus ensuring its physical significance, and its influence on the calculated alpha decay is presented. It is observed that the renormalization modifies the calculated half-life by∼40 %, which is a value three times larger than the experimental. Still, without appealing to any cluster structure from the beginning, i.e., all calculations were carried out using single nucleon degree of freedom.

Double Beta Decay Experiments: Recent Achievements and Future Prospects

The results of experiments on the search for and study of double beta decay processes obtained over the past 5 years (from 2018 to April 2023) are discussed. The results of the search for neutrinoless double beta decay are presented, in which a sensitivity of T1/2∼2×1024–2×1026 years (90% C.L.) has been achieved. The present conservative upper limit on effective Majorana neutrino mass ⟨mν⟩ was established from these experiments as 0.16 eV (90% C.L.). The results of experiments on recording and studying the processes of two-neutrino double beta decay in various nuclei (transitions to both the ground and excited states of daughter nuclei) are discussed too. The results of experiments on the search for majoron are also given. Possible progress in this field in the future is discussed.

Neutrinoless double beta decay and < η > mechanism in the left-right symmetric model

The neutrinoless double beta decay is studied in the framework of left-right symmetric model. The coexistence of left and right handed currents induces rather complicated interactions between the lepton and hadron sectors, called < λ > mechanism and < η > mechanism in addition to the conventional effective neutrino mass < mν > mechanism. In this letter, we study the possible magnification of < η > mechanism and the relatively vanishing of < λ > mechanism. The importance to survey 0νββ decay of different nuclei for specifying new physics beyond the Standard Model is also discussed.

Measurement of radon decays with the LVD-setup for neutrino searching

The LVD (Large Volume Detector), located at the Low Background Laboratory, Gran Sasso, Italy, is built to detect neutrinos from stellar core collapses in our Galaxy. The peculiarity of the search for rare events requires close attention to the background of the experiment, such as the natural radioactivity of the rock and detector materials and the interaction of cosmic ray muons underground. The LVD is capable of detecting gamma quanta from the decay of radon daughter nuclei. We convincingly show the connection between the change in the background counting rate from gammas in the detector and the change in the concentration of radon nuclei in the experimental hall. We also point out the existence of another source of radon change, this is seismic activity.

Neutrinoless double beta decay from lattice QCD: The short-distance π−→π+e−e− amplitude

This work presents a determination of potential short-distance contributions to the unphysical $\pi^-\rightarrow\pi^+ e^- e^-$ decay through lattice QCD calculations. The hadronic contributions to the transition amplitude are described by the pion matrix elements of five Standard Model Effective Field Theory operators, which are computed on five ensembles of domain-wall fermions with $N_f = 2 + 1$ quark flavors with a range of heavier-than-physical values of the light quark masses. The matrix elements are extrapolated to the continuum, physical light-quark mass, and infinite volume limit using a functional form derived in chiral Effective Field Theory ($\chi\mathrm{EFT}$). This extrapolation also yields the relevant low-energy constants of $\chi\mathrm{EFT}$, which are necessary input for $\chi\mathrm{EFT}$ calculations of neutrinoless double beta decay of nuclei.

Isospin-Symmetry Breaking within the Nuclear Shell Model: Present Status and Developments

The paper reviews the recent progress in the description of isospin-symmetry breaking within the nuclear shell model and applications to actual problems related to the structure and decay of exotic neutron-deficient nuclei and nuclei along the N=Z line, where N is the neutron number and Z the atomic number. The review recalls the fundamentals of the isospin formalism for two-nucleon and many-nucleon systems, including quantum numbers, the spectrum’s structure and selection rules for weak and electromagnetic transitions; and at the end, summarizes experimental signatures of isospin-symmetry breaking effects, which motivated efforts towards the creation of a relevant theoretical framework to describe those phenomena. The main approaches to construct accurate isospin-nonconserving Hamiltonians within the shell model are briefly described and recent advances in the description of the structure and (isospin-forbidden) decay modes of neutron-deficient nuclei are highlighted. The paper reviews major implications of the developed theoretical tools to (i) the fundamental interaction studies on nuclear decays and (ii) the estimation of the rates of nuclear reactions that are important for nuclear astrophysics. The shell model is shown to be one of the most suitable approaches to describing isospin-symmetry breaking in nuclear states at low energies. Further efforts in extending and refining the description to larger model spaces, and in developing first-principle theories to deal with isospin-symmetry breaking in many-nucleon systems, seem to be indispensable steps towards our better understanding of nuclear properties in the precision era.

Preparations for quantum simulations of quantum chromodynamics in 1+1 dimensions. II. Single-baryon β -decay in real time

A framework for quantum simulations of real-time weak decays of hadrons and nuclei in a two-flavor lattice theory in one spatial dimension is presented. A single generation of the Standard Model is found to require 16 qubits per spatial lattice site after mapping to spin operators via the Jordan-Wigner transformation. Both quantum chromodynamics and flavor-changing weak interactions are included in the dynamics, the latter through four-Fermi effective operators. Quantum circuits that implement time evolution in this lattice theory are developed and run on Quantinuum's H1-1 20-qubit trapped ion system to simulate the $\ensuremath{\beta}$-decay of a single baryon on one lattice site. These simulations include the initial state preparation and are performed for both one and two Trotter time steps. The potential intrinsic error-correction properties of this type of lattice theory are discussed, and the leading lattice Hamiltonian required to simulate $0\ensuremath{\nu}\ensuremath{\beta}\ensuremath{\beta}$-decay of nuclei induced by a neutrino Majorana mass term is provided.

A classroom alternative to simulate radioactive decay of nuclei

In this work we present a classroom alternative to simulate radioactive decay of nuclei. It consists of a game in which the students in a classroom are invited to participate in a kind of lottery. The students (around 45 in a typical classroom) take 20 “tickets” numbered at random from 1 to 50. As a whole we have 900 initial “tickets”. Then one student is asked to give a random number between 1 and 50 (for example 34) and the teacher gives a range of numbers from 34 to 38 or 30 to 34. The students cross the numbers in their list that coincide with the numbers given by the teacher. These numbers are the “lucky” ones and represent “nuclei” which decay, then someone gives another number and the process is repeated and the number of “lucky” tickets put in a list. Repetition of the process gives a sequence of numbers which are the number of “nuclei” survivingas the time goes on. The nuclei decaying are considered as stable ones. A plot of the surviving “nuclei” as a function of time (number of times the students are asked to cross the lucky numbers) gives a typical exponential decay. When one considers the case of nuclei A decaying into nuclei B decaying to nuclei C and this one is a stable one, using the corresponding differential equations one obtains the normal curves of nuclei as a function of time.

Lepton- and baryon-number violation in nuclear effective field theory

Lepton and baryon numbers are accidental symmetries in the effective field theory (EFT) of the Standard Model. Their violation would lead to spectacular nuclear decays which can be described with nuclear EFTs. I discuss ways in which two such decays — the neutrinoless double-beta decay of heavy nuclei and the disappearance of the deuteron — provide complementary information to processes that take place outside the nuclear environment — neutrino masses, nucleon decay, and neutron-antineutron oscillations.

Dynamical magnetic fields in heavy-ion collisions

The magnetic fields in heavy-ion collisions are important ingredients for many interesting phenomena, such as the Chiral Magnetic Effect, Chiral Magnetic Wave, the directed flow $v_1$ of $D^0$ mesons and the splitting of the spin polarization of the $\Lambda$/$\bar{\Lambda}$. Quantitative studies of these phenomena however suffer from limited understanding on the dynamical evolution of these fields in the medium created by the collisions, which remains a critical and challenging problem. The initial magnetic fields from the colliding nuclei decay very fast in the vacuum but their lifetime could be extended through medium response due to electrically conducting quarks and antiquarks. Here we perform a detailed analysis of such medium effect on the dynamical magnetic fields by numerically solving the Maxwell's equations concurrently with the expanding medium described by viscous hydrodynamics, under the assumption of negligible back reaction of the fields on the fluid evolution. Our results suggest a considerable enhancement of late time magnetic fields, the magnitude of which depends sensitively on the fireball expansion as well as the medium electric conductivity both before and during hydrodynamic stage.