Angular Distribution and CP Asymmetries in the Decays B->K^-pi^+e^-e^+ and B->pi^-pi^+e^-e^+

The short-distance Hamiltonian describing b->s(d)e^-e^+ in the standard model is used to obtain the decay spectrum of \bar{B}->K^-pi^+e^-e^+ and \bar{B}->pi^-pi^+e^-e^+, assuming the Kpi and pipi systems to be the decay products of K^* and rho respectively. Specific features calculated are (i) angular distribution of K^- (or pi^-) in the K^-pi^+ (or pi^-pi^+) centre-of-mass (c.m.) frame; (ii) angular distribution of e^- in the e^-e^+ c.m. frame; and (iii) the correlation between the meson and lepton planes. We also derive CP-violating observables obtained by combining the above decays with the conjugate processes B->K^+pi^-e^-e^+ and B->pi^-pi^+e^-e^+.Comment: 19 pages, REVTeX, no figures. Equations (2.19a), (2.19b), (5.5)-(5.7) have been corrected; all results remain unchanged. These changes will appear in an Erratum submitted to Phys. Rev.

Weak Phase gamma Using Isospin Analysis and Time Dependent Asymmetry in B_d -> K_s pi^+ pi^-

We present a method for measuring the weak phase gamma using isospin analysis of three body B decays into K pi pi channels. Differential decay widths and time dependent asymmetry in B_d -> K_s pi^+pi^- mode needs to be measured into even isospin pi pi states. The method can be used to extract gamma, as well as, the size of the electroweak penguin contributions. The technique is free from assumptions like SU(3) or neglect of any contributions to the decay amplitudes. By studying different regions of the Dalitz plot, it is possible to reduce the ambiguity in the value of gamma.Comment: 11 pages, 1 figur

Effect of methods of storing and treating potato seed tubers on the subsequent development of the potato plant

From the results, and from observations made in the field, it is possible to form a picture of the after-effects of various storage conditions, and the following conclusions are derived:1. Low temperature storage (40°P), F), and TCNB application can be used successfully to prolong the dormant period. Crops from seed stored at either conditions were similar in growth and yield of tubers of all grades.2. Temperature and light are the most important controlling factors in the growth of sprouts, a change in either of these factors can suddenly change the growth of sprouts. High temperature in bright light gives reasonably short sprouts, while high temperature in darkness causes long etiolated sprouts.3. The time at which shitting takes place, controls the number of sprouts per seed tuber. Seed tubers, when chitted immediately after lifting produce one (or sometimes 2 to 3) dominant sprout, usually on the apical region (apical dominance phase). When they are shitted at later dates, apical dominance gradually disappears and the number of sprouts per seed tuber increases (multiple sprouting phase).4. There was no evidence that a short period of heat treatment (65-70°F for 10 days) during the storage period of seed tubers, did anything to break apical dominance.5. Tubers with one sprout produce fewer tubers per hill than those with multiple sprouts, and those unsprouted, but result in a greater number of tubers per main-stem presumably due to the development of more nodes per dominant sprout and also to less competition among the tubers for plant food.6. There was no evidence that there is any yield advantage from sprouted seed as compared with unsprouted seed, provided plants from both are allowed to reach maturity. The results do suggest, however, that unsprouted seed produce a crop with a larger number of tubers than sprouted seed. From this there seems to be considerable merit in planting unsprouted seed tubers where a seed crop is desired. It should also be stressed that early planting of unsprouted seed is desirable.7. Plants from sprouted tubers emerge, flower, and tuberize about 10-15 days earlier than those stored at low temperature or treated with TCNB for the whole storage period.8. Desprouting seed tubers of the variety Arran. Pilot results in a crop with a significantly higher number of tubers. With this variety, therefore, there would seem to be some advantage, for seed potatoes, in planting unsprouted tubers which have lost sprouts during the riddling process, before planting.9. There was some evidence that seed tubers kept under chitting conditions (60 -65 °F) for a longer period (thus producing longer sprouts) produced plants with fewer tubers than seed shitted at the same time, but transferred to cool conditions (f" 40 °F) earlier (when sprouts 1 cm. long), Further corroboration of this is required.10. In all the comparisons the number of main -stems per hill was directly proportional to the number of tubers produced per hill, but the number of main -stems per hill was inversely proportional to the number of tubers per main - stem, i.e. a hill with fewer main -stems produced more tubers per main- stem than a hill with more main- stems.11. The effect of large seed and close spacing in producing a larger population of main -stems and tubers per acre was corroborated in this work. The yield and the number of seed sized tubers also increased significantly, while there was a decrease in the yield and number of ware -sized tubers

Fully-coupled analysis of jet mixing problems. Three-dimensional PNS model, SCIP3D

Numerical procedures formulated for the analysis of 3D jet mixing problems, as incorporated in the computer model, SCIP3D, are described. The overall methodology closely parallels that developed in the earlier 2D axisymmetric jet mixing model, SCIPVIS. SCIP3D integrates the 3D parabolized Navier-Stokes (PNS) jet mixing equations, cast in mapped cartesian or cylindrical coordinates, employing the explicit MacCormack Algorithm. A pressure split variant of this algorithm is employed in subsonic regions with a sublayer approximation utilized for treating the streamwise pressure component. SCIP3D contains both the ks and kW turbulence models, and employs a two component mixture approach to treat jet exhausts of arbitrary composition. Specialized grid procedures are used to adjust the grid growth in accordance with the growth of the jet, including a hybrid cartesian/cylindrical grid procedure for rectangular jets which moves the hybrid coordinate origin towards the flow origin as the jet transitions from a rectangular to circular shape. Numerous calculations are presented for rectangular mixing problems, as well as for a variety of basic unit problems exhibiting overall capabilities of SCIP3D

Modular networks emerge from multiconstraint optimization

Modular structure is ubiquitous among complex networks. We note that most such systems are subject to multiple structural and functional constraints, e.g., minimizing the average path length and the total number of links, while maximizing robustness against perturbations in node activity. We show that the optimal networks satisfying these three constraints are characterized by the existence of multiple subnetworks (modules) sparsely connected to each other. In addition, these modules have distinct hubs, resulting in an overall heterogeneous degree distribution.Comment: 5 pages, 4 figures; Published versio

Collective behavior of stock price movements in an emerging market

To investigate the universality of the structure of interactions in different markets, we analyze the cross-correlation matrix C of stock price fluctuations in the National Stock Exchange (NSE) of India. We find that this emerging market exhibits strong correlations in the movement of stock prices compared to developed markets, such as the New York Stock Exchange (NYSE). This is shown to be due to the dominant influence of a common market mode on the stock prices. By comparison, interactions between related stocks, e.g., those belonging to the same business sector, are much weaker. This lack of distinct sector identity in emerging markets is explicitly shown by reconstructing the network of mutually interacting stocks. Spectral analysis of C for NSE reveals that, the few largest eigenvalues deviate from the bulk of the spectrum predicted by random matrix theory, but they are far fewer in number compared to, e.g., NYSE. We show this to be due to the relative weakness of intra-sector interactions between stocks, compared to the market mode, by modeling stock price dynamics with a two-factor model. Our results suggest that the emergence of an internal structure comprising multiple groups of strongly coupled components is a signature of market development.Comment: 10 pages, 10 figure