Matter Decay Research Articles

Majorana CP-violating phases and NSI effects in neutrino decay

In this work, we investigate the impact of neutrino decay in the presence of non-standard interactions (NSI) along with the effects of the Majorana phase on neutrino decay in matter in the context of two-flavor neutrino oscillations. These effects are studied on neutrino oscillation probabilities P α β ≡ P(ν α → ν β ), and the difference ΔPαβ≡P(να→νβ)−P(ν¯α→ν¯β) for several accelerator and reactor neutrino experiments. We find that for P α β , the influence of the Majorana phase on decay in matter can be replicated by the simultaneous presence of both decay and NSI. However, precise measurements of the P α β and ΔP α β observables have the potential to unequivocally identify the presence of the Majorana phase by discerning its effects from the concurrent presence of both decay and NSI.

Analytic treatment of 3-flavor neutrino oscillation and decay in matter

We present compact analytic expressions for 3-flavor neutrino oscillation probabilities with invisible neutrino decay, where matter effects have been explicitly included. We take into account the possibility that the oscillation and decay components of the effective Hamiltonian do not commute. This is achieved by employing the techniques of inverse Baker-Campbell-Hausdorff (BCH) expansion and the Cayley-Hamilton theorem applied in the 3-flavor framework. If only the vacuum mass eigenstate ν3 decays, we show that the treatment of neutrino propagation may be reduced to an effective 2-flavor analysis in the One Mass Scale Dominance (OMSD) approximation. The oscillation probabilities for Pμμ, Pee, Peμ and Pμe — relevant for reactor, long baseline and atmospheric neutrino experiments — are obtained as perturbative expansions for the case of only ν3 decay, as well as for the more general scenario where all components of the decay matrix are non-zero. The analytic results thus obtained match the exact numerical results for constant density matter to a high precision and provide physical insights into possible effects of the decay of neutrinos as they propagate through Earth matter. We find that the effects of neutrino decay are most likely to be observable in Pμμ. We also point out that at any long baseline, the oscillation dips in Pμμ can show higher survival probabilities in the case with decay than without decay, and explain this feature using our analytic approximations.

Light Antinuclei from the Laboratory to the Cosmos

The antiproton was experimentally discovered at the Bevatron, Berkeley, in 1955, earning Segré and Chamberlain the 1959 Nobel Prize in Physics. After that, light antinuclei, bound states of antiprotons and antineutrons, have been observed in high-energy interactions in the laboratory from antideuteron to antihelium-4 [1]. In nature, antinuclei are extremely rare objects to be found. The search for antinuclei in space has received considerable attention in recent years, following the suggestion that cosmic antinuclei might be produced in the annihilation or decay of dark matter (DM) particles [2]. Alternatively, “secondary” antinuclei could be produced in ordinary high-energy interactions of primary cosmic rays with the interstellar matter in our galaxy. A precise assessment of the background constituted by secondary antinuclei is pivotal for these searches and for the interpretation of the results. The spectrum of antiprotons observed in cosmic rays is consistent with the hypothesis of secondary production. No evidence of primary antiprotons, antihelium, and antideuterons has been found in the cosmic radiation so far. It is clear that the study of the formation of composite antimatter objects cannot but rely on samples of antimatter produced in the laboratory. Comprehensive measurements of different nuclear (and hypernuclear1) species are necessary to meaningfully constrain formation models and require large data samples to be inspected, as the production of nuclear clusters becomes rarer with increasing mass number. Additional fundamental constraints to the production models are obtained from systematic studies of different particle sources, from ­proton–proton (pp) to heavy-ion collisions, where the size of the system can be experimentally controlled based on the number of particles (multiplicity) produced in the collision.

Molecular characterisation of fungi associated with sewage-impacted soil

The decay of faecal matter from a septic system causes the arousal of fungi in the surrounding soil. These fungi can cause diseases if there is sewage spillage containing untreated or improperly treated wastewaters. Molecular techniques of identification of fungi have shown to be more dependable than traditional methods of identifying fungal species. This study was carried out to identify the fungal species associated with soil obtained from sewage-impacted soil near a septic tank using both traditional cultural techniques and molecular method. Fungi associated with the soil samples were isolated using serial dilution and Potato Dextrose Agar (PDA) method. Deoxyribonucleic Acid (DNA) was extracted from the pure cultures of fungal isolates using Quick DNA Fungal/Bacterial Miniprep kit. Polymerase Chain Reaction (PCR) amplification of internal transcribed spacer (ITS) region of the fungal isolates was carried out using universal primer pair; ITS4 and ITS5. The PCR products were sequenced and the sequences were blasted against National Centre for Biotechnology Information database. The result of the nucleotide sequence analysis revealed the identity of the isolates as Trichoderma harzanium with 580 base pairs and Aspergillus welwitschiae with 560 base pairs. Sequences of the isolates were aligned and compared with sequences on GenBank and a phylogenetic tree was constructed. The cultural method only aided in suggesting the suspected genera of the isolates while the molecular method was able to identify the isolates to the species level. This study will promote the knowledge of the fungal species associated with sewage-impacted soil and also aid researchers in proffering ways to enhance the prevention/control of diseases associated with sewage spill.
 Keyword: Septic tank, fungi, soil, phylogeny, sequencing

Применение современных конструкционных материалов, методик и детекторов для низкофоновых экспериментов

Good examples of the key tasks of modern non-accelerator physics are the searches for dark matter and neutrinoless double beta decay. The essential requirement for such an experiment is the requirement of a minimal background level. The ways to reduce it are quite obvious and widely used in the ongoing experiments. So, the experiments are located in the underground laboratories, a careful selection of structural materials is carried out, and various techniques for active background suppression are used. However, in order to advance in new generation projects in addition to a serious increase in the detector mass, the significant reduction of the background level (which is already pretty low) is required. Very important irremovable background sources are the structural materials close to the detector(s). In this regard, it is extremely important not only to constantly search for new low-background materials, but also to ensure that radioactive contaminants cannot be introduced at the stage of the required parts production. In this article the results of the successful using of structural parts produced by modern methods from novel low-background materials during the preparation of the new generation ultra-low-background experiment searching for neutrinoless double beta decay are presented.

The time of the short twentieth century. Growth of values and decay of matter

The time of the short twentieth century. Growth of values and decay of matter

Second order Langevin equation and definition of quantum gravity by stochastic quantisation

Euclidean quantum gravity might be defined by stochastic quantisation that is governed by a higher order Langevin equation rather than a first order stochastic equation. In a transitory phase where the Lorentz time cannot be defined, the parameter that orders the evolution of quantum gravity phenomena is the stochastic time. This changes the definition of causality in the period of primordial cosmology. The prediction of stochastically quantised gravity is that there will a transition from an oscillating quantum phase to a semi-classical one, when the Lorentz time emerges. The end of the transition, as it can be observed from now and described by inflation models, is a diluted Universe, following the inflation phenomenological evolution. It is filled at the beginning with scattered classical primordial black holes. The smallest ones will quickly decay in matter, with a standard quantum field theory evolution till our period. The stable heavier black holes will remain, forming a good fraction of the dark matter and the large black holes observed in the galaxies. In a theoretically related way, this framework suggests the possibility of a gravitational parton content for “point-like” particles, in the same five dimensional quantum field theory context as in the primordial cosmology, with a (+−−−−) signature for the 5d metrics. The very precise and explicit result expressed in this paper is actually far more modest than its motivation. We compute explicitly the meaning of a second order Langevin equation in zero dimensions and define precisely what is second order stochastic quantisation in a soluble case.

Iron index as an organic matter decay intensity indicator in a shallow groundwater system highly contaminated with phenol (case study in northern Poland)

The decay of organic matter of anthropogenic origin in a highly contaminated shallow groundwater system occurs permanently regardless of the availability of oxygen. Oxidation of organic matter smoothly changes from aerobic to anaerobic and vice versa. Hydrogeochemical transformations occurring in the interior of the contaminant plume are conditioned by the position in the 3D zone of the so-called “redox reactor” and its edge. The primary reaction initiating the decay of organic matter (TOC max 1620 mg/L, phenol max 613 mg/L) is its aerobic oxidation. In the case of the consumption of free oxygen, the decay undergoes anaerobic oxidation, where the source of electrons are oxides and hydroxides (MnO2, Fe(OH)3). As a result of these reactions, mobile ions Mn2+ and Fe2+ pass into the aqueous environment creating a concentration anomaly (max 15 mg/L for Mn2+, 673 mg/L for Fe2+). The presence of Fe2+ in groundwater is crucial. A strong correlation between the organic matter decay processes and concentration of the Fe2+ showed that “iron index” may be a preliminary marker for the hydrogeochemical recognition of aquifer and allows to diagnose zones with an intense organic matter decay, especially by anaerobic oxidation through redox reactions. At the edge of the “redox reactor” redox sensitive metals (Fe2+, Mn2+ and also Cu2+, Cr3+, Hg2+) undergo aerobic oxidation due to the access of oxygen as a result of mixing of contaminated groundwater and oxygenated pure Quaternary water. These transformations produce oxides and hydroxides (MnO2, Fe(OH)3)—new reaction products, however, are used for anaerobic oxidation of organic matter. Organic matter decay is an cyclic system of redox processes up to the full decay of pollutants and generation of the anomalously high concentrations of redox sensitive metals in the ground.

Re-evaluation of depositional models for the lower Permian Patchawarra Formation, Cooper Basin, South Australia: implications for petroleum exploration

The Late Carboniferous–Triassic Cooper Basin is Australia’s most prolific onshore petroleum province. The lower Permian Patchawarra Formation, which is up to 680 m thick and consists of up to 10% coal, is a major exploration target in the basin. Eighteen cores through the formation have been logged to re-evaluate the existing fluviolacustrine depositional model. The siliciclastics form fining- and coarsening-upward sequences that are 1–10 m thick. They are predominately fine-grained with abundant lenticular bedding, wavy bedding and thinly interlaminated siltstones and clays resembling varves. Granules and pebbles, interpreted as dropstones, are present throughout the formation. Coal beds are up to 60 m thick and rich in inertinite. Other than the coal beds, there is little evidence of the establishment of terrestrial conditions: roots are rare and there are no siliciclastic palaeosols. The siliciclastics are interpreted as the deposits of a large glaciolacustrine system, with the fining-upward successions deposited in subaqueous channels cut by hyperpycnal flows and the coarsening-upward successions deposited as overbank splays between those channels. Hyperpycnal flows may have resulted from sediment-laden cold water emanating from glacially-fed rivers, similar to those seen in many large glacial lakes in high latitudes and altitudes today. Much of the coal is interpreted as the accumulation of peats from floating mires that covered large parts of the glaciolacustrine system at certain time intervals. The high inertinite content of many coals is interpreted as the decay of organic matter within the floating mire. These new interpretations have the potential to enhance reservoir characterisation within the basin.

The Concept of Cluster Evolutionary Minerageny in the Earth’s History

A new concept of cluster evolutionary minerageny is based on the idea of the formation of the Earth from the primary stellar material, which was preserved in the planet’s core. Its further destruction due to decay of heavy nuclear matter results in fragmentation of the material until the appearance of superheavy elements with their further nuclear dissociation. As a result, protomagma arises and penetrates to the upper mantle in the form of plume flows. This process supports the reactions that control the formation of chemical elements, minerals, ores, and rocks, which compose the upper mantle and the Earth’s crust. The processes of nuclear dissociation lead to the release of energy and decompression of matter. This initiates an increase in the Earth’s volume, its geotectonic activity, and the creation of the hydrosphere and atmosphere.

The concept of cluster evolution minerageny in the Earth’s history

The new concept of cluster evolutionary mineralogy is based on the idea of the formation of the Earth from the primary stellar matter, which was preserved in the cores of the planets. The consequent destruction of it, as a result of the decay of heavy nuclear matter, leads to fragmentation of the substance until the appearance of superheavy elements with their further nuclear dissociation. As a result, a protomagma emerges, which enters the upper mantle in the form of plume flows. This process supports the reactions that result in the formation of chemical elements, minerals, ores and rocks, from which the upper mantle and the crust are formed. The processes of nuclear dissociation lead to the release of energy and the decomposition of matter, which initiates the growth of the earth's volume, its geotectonic activity, and the appearance of the hydrosphere and the atmosphere.

Biogas residue parameterization for soil organic matter modeling.

A variety of biogas residues (BGRs) have been used as organic fertilizer in agriculture. The use of these residues affects the storage of soil organic matter (SOM). In most cases, SOM changes can only be determined in long-term observations. Therefore, predictive modeling can be an efficient alternative, provided that the parameters required by the model are known for the considered BGRs. This study was conducted as a first approach to estimating the organic matter (OM) turnover parameters of BGRs for process modeling. We used carbon mineralization data from six BGRs from an incubation experiment, representing a range of substrate inputs, to calculate a turnover coefficient k controlling the velocity of fresh organic matter (FOM) decay and a synthesis coefficient η describing the SOM creation from FOM. An SOM turnover model was applied in inverse mode to identify both parameters. In a second step, we related the parameters k and η to chemical properties of the corresponding BGRs using a linear regression model and applied them to a long-term scenario simulation. According to the results of the incubation experiment, the k values ranged between 0.28 and 0.58 d-1 depending on the chemical composition of the FOM. The estimated η values ranged between 0.8 and 0.89. The best linear relationship of k was found to occur with pH (R2 = 0.863). Parameter η is related to the Ct/Norg ratio (R2 = 0.696). Long-term scenario simulations emphasized the necessity of specific k and η values related to the chemical properties for each BGR. However, further research is needed to validate and improve these preliminary results.

Biosurfactant assisted degradation of high ring number PAHs using a two-stage CSTR/fully submerged fixed-film bioreactors in series

Polycyclic aromatic hydrocarbons (PAHs) are released into the environment through natural activities such as forest fires and incomplete combustion of wood and decay of vegetable matter. Anthropogenic activities that release PAHs into the environment include activities such as combustion of coal and petroleum product processing. PAHs are not easily accessible to bacteria for degradation due to their low solubility in water. Among the notorious PAH are the high ring number PAHs (ring-number 4 - 7) that are extremely difficult to degrade due to their hydrophobicity which renders them insoluble in water. One such compound, fluoranthene (Flu), is a four ring PAH classified as a High Molecular Weight (HMW) compound. Due to the difficulty to degrade these compounds, it is necessary to find novel and environmentally compatible methods for treating them. In this study, PAH degrading organisms isolated from engine oil contaminated soil achieved 92 % removal of Flu in a fixed-film bioreactor operated at retention time of 1.19 h at 0.86 L.h-1 under fully submerged conditions. The predominant species of biosurfactant producing bacteria in the reactor were determined to be dominated by Pseudomonas aeruginosa using 16S rRNA genotype fingerprinting analysis.

PeV IceCube signals and Dark Matter relic abundance in modified cosmologies

The discovery by the IceCube experiment of a high-energy astrophysical neutrino flux with energies of the order of PeV, has opened new scenarios in astroparticles physics. A possibility to explain this phenomenon is to consider the minimal models of Dark Matter (DM) decay, the 4-dimensional operator sim y_{alpha chi }overline{{L_{L_{alpha }}}}, H, chi , which is also able to generate the correct abundance of DM in the Universe. Assuming that the cosmological background evolves according to the standard cosmological model, it follows that the rate of DM decay Gamma _chi sim |y_{alpha chi }|^2 needed to get the correct DM relic abundance (Gamma _chi sim 10^{-58}) differs by many orders of magnitude with respect that one needed to explain the IceCube data (Gamma _chi sim 10^{-25}), making the four-dimensional operator unsuitable. In this paper we show that assuming that the early Universe evolution is governed by a modified cosmology, the discrepancy between the two the DM decay rates can be reconciled, and both the IceCube neutrino rate and relic density can be explained in a minimal model.

How traces of pollutants in the environment modify bioremediation efficiency performed with Desulfovibrio vulgaris , and the advantage of an optimization protocol using soft chemicals

Abstract In recent years, Desulfovibrio vulgaris has been used to clean marble statues affected by gypsum black crusts. Many studies showed that “biocleaning” is very selective: chemical-cleaning products cannot distinguish the decay product, which has to be eliminated, from the original stone that must be fully preserved. Besides, they may cause direct and indirect damage to limestone artefacts. Instead, Sulphate Reducing Bacteria (SRB), as D. vulgaris, are able to remove just the decay matter. D. vulgaris uses SO42− ions (gypsum constituent) in its own respiratory chain; while, it does not interact with the calcium carbonate layer underneath because it does not need carbonate ions for its catabolism. However, “biocleaning” shows a large variability in the efficiency depending on the environment. If the cleaning results are not consistent, “biocleaning” cannot become an alternative cleaning method. Therefore, it is extremely important to uncover the reasons behind these differences, and to identify possible strategies to overcome the problem. The large variability of efficiency of “biocleaning” can be explained by the close relationship between the bacterial community and pollutants previously entrapped in the substrate. The aim of this work is to ascertain this hypothesis and identify how the toxic effects of the inorganic pollutants could be mitigated to improve the efficiency of this new cleaning method. In order to identify which kinds of pollutants were present and how they interact with the bacterial community during “biocleaning”, two different steps have been carried out. The first step consists in an environmental/ecotoxicological study that characterized the substrate and proves if inorganic pollutants could affect the bacterial survival. Toxic heavy metals (i.e. Pb > Zn > Cu) were found into the chalky matrix by ICP-AES and ICP-MS analyses and the followed toxicological kinetic studies demonstrated that they reduced the bacterial growth and activity. The second step consists of an optimization of the in situ bioremediation protocol, to create a better condition for the “biocleaning” application. A soft chemical pre-treatment was performed before the bacterial application using Tween 20 surfactant. Tween 20 (non-ionic surfactant) was able to reduce the adverse effects of pollutants, decreasing their superficial amount. Moreover, the method did not influence bacterial growth and activity since it did not have superficial charges and it did not change the pH value of the surroundings. This work proves that inorganic pollutants present in the gypsum decay layer can drastically reduce the bacterial growth and, at the same time, they decrease heavily the bioremediation efficiency. This study provides a soft chemical optimization strategy, helping to overcome the problem and to improve the “biocleaning” efficiency.

Petrographic characteristics and paleoenvironmental history of Eocene lignites of Cambay basin, Western India

Lignite samples collected from Vastan, Rajpardi and Tadkeshwar lignite mines of Cambay basin (Gujarat) were subjected to organic petrographic investigations and geochemical analyses and the data, thus generated, is used to reconstruct the paleodepositional history of these lignite sequences. The lignites of Cambay basin dominantly comprise huminite maceral group (71.6%–86.3%) followed by liptinite (10.1%–19.3%) and inertinite (3.6%–11.0%) maceral groups. The mineral matter varies from 9.0% to 20.0%. The petrography based facies model indicates that these lignites have high values of gelification index (GI) and low tissue preservation index revealing a continuous wet condition in the basin and a relatively slower rate of subsidence during the decay of organic matter. On several occasions, during the formation of seams in Tadkeshwar, Rajpardi and Vastan mines, the value of GI exceeded 10 which indicates a forest permanently flooded and the cause of pronounced degree of degradation. However, few sections in Tadkeshwar seam had relatively drier spells of environmental conditions due to fluctuation in the water table as revealed by moderately high content of inertinite macerals. This is specially indicated by the occurrence of funginite which normally thrives in the upper oxygenated peatigenic layer and indicates prevalence of oxic conditions during plant deposition. Such conditions prevailed during a transgressive phase but there were intermittent fluvial activities also giving rise to supratidal flood plain as reflected in the form of associated carbonaceous shales in the basin.

Seasonal variations in the vertical structure of pelagian water stratum in the Southern Baikal

For the first time, T,S-analysis was used to determine the specifics of seasonal variations in the vertical structure of Lake Baikal active layer. In the under-ice period, the active layer includes the under-ice, top winter, and upper intermediate water masses. The under-ice water mass, unlike other masses, shows an increase in mineralization to 100.74 mg/kg, which corresponds to a release of 71.1 g salt under 1 m2 of water surface in a layer 0–40 m in the process of salt freezing out during ice cover formation and accretion. In the phases of mixing (homothermy), the water masses of the active layer transform into a surface homogeneous mass. In summer and autumn, surface and upper intermediate water masses, separated by a water mass of summer thermocline can be identified. A specific feature of the summer thermocline water mass is the increased sum of ions because of an increase in HCO 3 - concentration at the decay of organic matter accumulating in the bottom part of the thermocline. The existence of the under-ice water mass and the water mass of summer thermocline was established in Lake Baikal for the first time. In the deep-water zone (>250 m), except for the bottom parts, the lower water masses (the lower intermediate and the deep) are permanent, their characteristics remaining stable during the year. The changes in the bottom water mass are due to the character of the processes of bottom water renewal.

A new actinomycete from a Guadalupian vertebrate coprolite from Brazil

Coprolites (fossil feces) are important sources of evidence of ancient food webs and ecosystems. Actinomycetes are a fundamental component in the decay of organic matter, and serve as catalysts for nutrient cycles. Recently, gas vesicles filled with numerous verrucose colonies of substrate mycelium of an actinomycete were discovered inside a fossilized spiral amphipolar fish coprolite recovered from mid–Permian deposits of Brazil. These colonies are composed of masses of substrate hyphae, some of which are undergoing segmentation. Arising from the colonies are chains of spores separated by narrow, elongate connectives. The fossil actinomycete is described below as Palaeostromatus diairetus gen. et sp. nov. and represents the oldest known actinomycete associated with vertebrate deposits. Since the colonies occur only inside the coprolite, either Palaeostromatus diairetus gen. et sp. nov. was part of the gut flora or it was acquired from a food source. The only other remains in the coprolite are eighteen paleoniscoid fish scales, which suggests that the producer was a carnivorous/omnivorous fish. This is the oldest record of a direct interaction between vertebrates and actinomycetes.

Matter perturbations in scaling cosmology

A suitable nonlinear interaction between dark matter with an energy density $\rho_{M}$ and dark energy with an energy density $\rho_{X}$ is known to give rise to a non-canonical scaling $\rho_{M} \propto \rho_{X}a^{-\xi}$ where $\xi$ is a parameter which generally deviates from $\xi =3$. Here we present a covariant generalization of this class of models and investigate the corresponding perturbation dynamics. The resulting matter power spectrum for the special case of a time-varying Lambda model is compared with data from the SDSS DR9 catalogue. We find a best-fit value of $\xi = 3.25$ which corresponds to a decay of dark matter into the cosmological term. Our results are compatible with the $\Lambda$CDM model at the 2$\sigma$ confidence level.

IceCube Events from Decaying Dark Matter with Neutrino Portal

IceCube has observed several PeV neutrino events whose astrophysical origin has not been identified. In this proceeding, we discuss heavy decaying dark matter may be responsible for these neutrinos. Dark matter [Formula: see text] is constructed to communicate with standard model particles through the neutrino-portal interaction. We calculate both total and differential decay width for the dominant three-body decay of dark matter and show that to fit the data, the required mass is around [Formula: see text](10 PeV) and lifetime is about [Formula: see text]s.