R-parity-violating trilinear couplings and recent neutrino data

The nontrivial structure of the neutrino mass matrix, suggested by the recent Super-Kamiokande results and data from other neutrino experiments, can be reproduced in R-parity-violating supersymmetric theories. This requires sets of products of R-parity-violating trilinear couplings to take appropriately chosen values. It is shown that the existing constraints on these couplings are satisfied by these choices.Comment: Latex, 8 pages, including 1 Fig; minor changes in the text, some references added, to appear in Phys. Rev. D (Rapid Communication

Mycorrhiza-mediated phosphorus use efficiency in plants

Abstract Phosphorus is the second most important plant nutrient after nitrogen that is critical for plant growth, it contributes up to about 0.2% dry mass. It can become deficient in different agro ecological conditions. In soil, it may be present in relatively large amounts, but it is one of the most difficult nutrients for plants to acquire. Much of it is poorly available because of the very low solubility of phosphates of iron, aluminium, and calcium, leading to soil solution concentrations of 10 μM or less and very low mobility. Plants have evolved a range of strategies that increase either soil solution phosphorus uptake capacity or availability in soil. The most exceedingly common of these strategies worldwide is inoculation of plant roots by arbuscular mycorrhizal fungi. Inoculation can promote plant growth by enhancing phosphate uptake from soil, particularly when the supply of phosphorus limits growth

INFLUENCE OF ORGANIC MANURES ON PRODUCTIVITY OF TWO VARIETIES OF RICE

Field experiment was conducted during 2003-04 to study the effect of vermicompost, farmyard manure and water hyacinth compost in comparison to chemically fertilized and unfertilized plots on crop-plants in HYV Swarna and local variety Magaisal. The experiment followed split plot design with two varieties of rice in the main plots and five nutrient sources randomized in sub plots. Signifi cant variation in grain yield between the varieties, among the nutrient sources and their interactions was observed. Grain yield recorded in HYV Swarna was higher to local variety Mugaisal irrespective of the treatments and hence Swarna was considered to be more tolerant to Mugaisal. Among the nutrient sources, treatment with vermicompost imparted maximum grain yield to all other nutrient sources irrespective of varieties

Trichoderma: A part of possible answer towards crop residue disposal

India is one of the leading countries in agricultural production and generate large volume of crop residue. Increasing demand for food grains due to growing population leads to generation of crop residues. Due to lack of proper disposal mechanism of crop residue, farmers burn the residue which release greenhouse gases (GHGs) into the atmosphere, and poses great threat to environment as well as human health. The residue burning causes greater carbon emission and nutrient losses which otherwise incorporated into the soil system may substantially improve the soil biodiversity. Besides several practices of crop residue management, the most feasible method for farmers is incorporation of residue into the soil with the inoculation of microbes. In soil system the ability of microbial community in degrading organic substances is well known. In the early stages of residue decomposition simple substrates like carbohydrates are degraded by bacteria, but in later stages degradation of complex constituents viz., cellulose, lignin needs microbes which are capable of secreting enzymes like cellulase, acting on complex organic substrates. In this context, cellulolytic micro organisms like Trichoderma have the potential and emerging as an important microbial inoculants to enhance the rate of decomposition as well as alleviate the effect of residue burning

On-farm seed priming interventions in agronomic crops

Priming techniques are gaining importance in agriculture with the increase in environmental stresses. Resource-poor farmers are in urgent need of such techniques as they are simple, economical, and value-added intervention associated with low-risk bearing factors. Seed enhancement methods are key to improve seed performance and achieve a good stand establishment. Worldwide beneficial effects of priming are recorded. But these technologies have still not reached most farmers. This review highlights the importance of on-farm priming strategies in modern crop production system to yield better productivity and obtain higher economic returns. Stimulation of the pre-germination metabolic changes by priming is necessary to overcome the environmental challenges that a plant can encounter. Thus, the study also focuses on mechanisms associated with priming-induced stress tolerance of crops. Various safe practical methods of seed priming can be easily adopted by the farming community to alleviate the levels of different stresses which can hamper productivity. Simultaneously they can produce good quality seeds and use them further for the next crop cycle cutting the costs of seed purchase.</p

Cosmological constraints on R-parity violation from neutrino decay

If the neutrino mass is non-zero, as hinted by several experiments, then R-parity-violating supersymmetric Yukawa couplings can drive a heavy neutrino decay into lighter states. The heavy neutrino may either decay radiatively into a lighter neutrino, or it may decay into three light neutrinos through a Z-mediated penguin. For a given mass of the decaying neutrino, we calculate its lifetime for the various modes, each mode requiring certain pairs of R-parity-violating couplings be non-zero. We then check whether the calculated lifetimes fall in zones allowed or excluded by cosmological requirements. For the latter case, we derive stringent new constraints on the corresponding products of R-parity-violating couplings for given values of the decaying neutrino mass.Comment: 13 pages, Latex, uses axodraw.sty; version to appear in Physical Review

Can R-parity violation lower sin⁡2β\sin 2\beta?

Recent time-dependent CP asymmetry measurements in the $B_d \to J/\psi K_S$ channel by the BaBar and Belle Collaborations yield somewhat lower values of $\sin 2\beta$ compared to the one obtained from the standard model fit. If the inconsistency between these numbers persists with more statistics, this will signal new physics contaminating the $B_d \to J/\psi K_S$ channel, thus disturbing the extraction of $\beta$. We show that the R-parity-violating interactions in supersymmetric theories can provide extra new phases which play a role in significantly reducing the above CP asymmetry, thus explaining why BaBar and Belle report lower values of $\sin 2\beta$. The same couplings also affect the $B_d \to \phi K_S$ decay rate and asymmetry, explain the $B \to \eta' K$ anomaly, and predict nonzero CP asymmetry in dominant $B_s$ decays. The scenario will be tested in the ongoing and upcoming B factories.Comment: Latex, 9 pages, 1 PS figure, requires psfig.sty; v2: minor cosmetic changes in text, one reference added; v3: more references and further clarifying remarks to match the version to appear in PL