Study of a Narrow pi+ pi- Peak at about 755 MeV/c**2 in pbar n --> 2 pi+ 3 pi- Annihilation at Rest

A narrow peak in the pi+ pi- mass distribution was seen by the Rome-Syracuse Collaboration in pbar n --> 2 pi+ 3 pi- annihilation at rest in 1970. It was ignored for 40 years. The reanalysis of this peak finds that it has the mass 757.4 +- 2.8_stat +- 1.1_sys MeV/c**2 and a width consistent with the experimental resolution. The evidence of the peak is 5.2 standard deviations. The peak is generated in (1.03 +- 0.21_stat +- 0.21_sys)% of the pbar n annihilations at rest. No spin analysis is possible with the statistics of the experiment but there are arguments suggesting that it has JP = 0+.Comment: 8 pages, 3 figures, talk given at the 13.th International Conference on Hadron Spectroscopy, Tallahassee, FL, USA, November 29 - December 4, 2009. Superseeds arXiv:0902.1126 [hep-ex]

Study of the D0 --> pi+ pi- pi0 decay at BABAR

The Dalitz-plot of the Decay D0 --> pi+ pi- pi0 measured by the BABAR Collaboration shows the structure of a final state having quantum numbers IG JPC = 0- 0--. An isospin analysis of the Daliz-plot finds that the I = 0 contribution is about 96%. This high I = 0 contribution is unexpected because the weak interaction violates the isospin.Comment: 8 pages, 2 figures, talk given at the 13.th International Conference on Hadron Spectroscopy, Tallahassee, FL, USA, November 29 - December 4, 2009. The second version corrects the errors of the amplitudes in the second column of Table 1

Isospin analysis of D0 decay to three pions

The final state of the decay D0 --> pi+ pi- pi0 is analyzed in terms of isospin eigenstates. It is shown that the final state is dominated by the isospin-0 component. This suggests that isospin considerations may provide insight into this and perhaps other \Dz-meson decay. We also discuss the isospin nature of the nonresonant contribution in the decay, which can be further understood by studying the decay D0 --> pi0 pi0 pi0.Comment: 10 pages, 2 postscript figures, submitted to Phys Rev

A single polyploidization event at the origin of the tetraploid genome of Coffea arabica is responsible for the extremely low genetic variation in wild and cultivated germplasm

The genome of the allotetraploid species Coffea arabica L. was sequenced to assemble independently the two component subgenomes (putatively deriving from C. canephora and C. eugenioides) and to perform a genome-wide analysis of the genetic diversity in cultivated coffee germplasm and in wild populations growing in the center of origin of the species. We assembled a total length of 1.536 Gbp, 444 Mb and 527 Mb of which were assigned to the canephora and eugenioides subgenomes, respectively, and predicted 46,562 gene models, 21,254 and 22,888 of which were assigned to the canephora and to the eugeniodes subgenome, respectively. Through a genome-wide SNP genotyping of 736 C. arabica accessions, we analyzed the genetic diversity in the species and its relationship with geographic distribution and historical records. We observed a weak population structure due to low-frequency derived alleles and highly negative values of Taijma's D, suggesting a recent and severe bottleneck, most likely resulting from a single event of polyploidization, not only for the cultivated germplasm but also for the entire species. This conclusion is strongly supported by forward simulations of mutation accumulation. However, PCA revealed a cline of genetic diversity reflecting a west-to-east geographical distribution from the center of origin in East Africa to the Arabian Peninsula. The extremely low levels of variation observed in the species, as a consequence of the polyploidization event, make the exploitation of diversity within the species for breeding purposes less interesting than in most crop species and stress the need for introgression of new variability from the diploid progenitors

Grapevine field experiments reveal the contribution of genotype, the influence of environment and the effect of their interaction (GxE) on berry transcriptome

Changes in the performance of genotypes in different environments are defined as genotype x environment (GxE) interactions. In grapevine (Vitis vinifera), complex interactions between different genotypes and climate, soil, and farming practices yield unique berry qualities. However, the molecular basis of this phenomenon remains unclear. To dissect the basis of grapevine GxE interactions, we characterized berry transcriptome plasticity, genome methylation landscape, and within-genotype allelic diversity in two genotypes, cultivated in three different environments, over two vintages. We identified, through a novel data-mining pipeline, genes with expression profiles that were unaffected by genotype or environment, genotype-dependent but unaffected by the environment, environmentally-dependent regardless of genotype, and GxE-related. The GxE-related genes showed different degrees of within-cultivar allelic diversity in the two genotypes and were enriched for stress responses, signal transduction and secondary metabolism categories. Our study unraveled the mutual relationships between genotypic and environmental variables during GxE interaction in a woody perennial species, providing a reference model to explore how cultivated fruit crops respond to diverse environments. Also, the pivotal role of vineyard location in determining the performance of different varieties, by enhancing berry quality traits, was unraveled

First observation of a narrow charm-strange meson DsJ(2632) -> Ds eta and D0 K+

We report the first observation of a charm-strange meson DsJ(2632) at a mass of 2632.6+/-1.6 MeV/c^2 in data from SELEX, the charm hadro-production experiment E781 at Fermilab. This state is seen in two decay modes, Ds eta and D0 K+. In the Ds eta decay mode we observe an excess of 49.3 events with a significance of 7.2sigma at a mass of 2635.9+/-2.9 MeV/c^2. There is a corresponding peak of 14 events with a significance of 5.3sigma at 2631.5+/-1.9 MeV/c^2 in the decay mode D0 K+. The decay width of this state is <17 MeV/c^2 at 90% confidence level. The relative branching ratio Gamma(D0K+)/Gamma(Dseta) is 0.16+/-0.06. The mechanism which keeps this state narrow is unclear. Its decay pattern is also unusual, being dominated by the Ds eta decay mode.Comment: 5 pages, 3 included eps figures. v2 as accepted for publication by PR

Using computer simulation to aid the research of drilling processes

Drilling wells is one of the primary methods used for mineral exploration. Scientific studies have aimed at improving the technical and economic aspects of drilling because of the current competitive economic conditions. Note that the primary topic of these studies has been developing new effective rock-cutting tools. To design a new rock-cutting tool, a thorough, reliable, and accurate study of the processes that occur during drilling is necessary. During drilling, mechanical, hydraulic, thermal, and chemical phenomena, which are interdependent and affect the performance of a drilling tool, simultaneously occur; therefore, a systematic, integrated approach is required for studying drilling processes. Field-based and laboratory experiments are quite tedious to perform and require high material costs, and it is often not possible to separately evaluate small elements of the drilling model. Therefore, computer simulation is an important research tool that enables accurate and reliable visualization of even small parts of the model. The aim. The aim of this study is to examine the potential for computer simulation of the processes that occur during drilling. Objective. In this study, we evaluated the simulation features of various software products, such as KOMPAS-3D, ANSYS, Delphi, and LabVIEW, for their utility in studying the processes that occur during drilling. The possibility of computer simulation for studying drilling processes, including its advantages and disadvantages, are demonstrated. The results are obtained from a model that simulates a rock cutting tool. The main uses of the rock cutting tool are outlined, and the drilling simulation development is planned. Choice of research method. The study of the capabilities of existing modern software products, for use in drilling process research, is carried out by an analytical review method

Study of the D0 \to Pi Pi- Pi0 Decay at BaBar

The Dalitz-plot of the decay D{sup 0} {yields} {pi}{sup +}{pi}{sup -}{pi}{sup 0} measured by the BABAR collaboration shows the structure of a final state having quantum numbers I{sup G}J{sup PC} = 0{sup -}0{sup 2-}. An isospin analysis of this Dalitz-plot finds that the fraction of the I = 0 contribution is about 96%. This high I = 0 contribution is unexpected because the weak interaction violates the isospin