Extracting ππ\pi\pi SS-wave scattering lengths from cusp effect in heavy quarkonium dipion transitions

Charge-exchange rescattering $\pi^+\pi^-\to \pi^0\pi^0$ leads to a cusp effect in the $\pi^0\pi^0$ invariant mass spectrum of processes with $\pi^0\pi^0$ in the final state which can be used to measure $\pi\pi$ $S$-wave scattering lengths. Employing a non-relativistic effective field theory, we discuss the possibility of extracting the scattering lengths in heavy quarkonium $\pi^0\pi^0$ transitions. The transition $\Upsilon(3S)\to\Upsilon(2S)\pi^0\pi^0$ is studied in details. We discuss the precision that can be reached in such an extraction for a certain number of events.Comment: 15 pages, 7 figures, 1 tabl

Cancellation of divergences in unitary gauge calculation of H→γγH \to \gamma \gamma process via one W loop, and application

Following the thread of R. Gastmans, S. L. Wu and T. T. Wu, the calculation in the unitary gauge for the $H \to \gamma \gamma$ process via one W loop is repeated, without the specific choice of the independent integrated loop momentum at the beginning. We start from the 'original' definition of each Feynman diagram, and show that the 4-momentum conservation and the Ward identity of the W-W-photon vertex can guarantee the cancellation of all terms among the Feynman diagrams which are to be integrated to give divergences higher than logarithmic. The remaining terms are to the most logarithmically divergent, hence is independent from the set of integrated loop momentum. This way of doing calculation is applied to $H \to \gamma Z$ process via one W loop in the unitary gauge, the divergences proportional to $M_Z^2/M^3$ including quadratic ones are all cancelled, and terms proportional to $M_Z^2/M^3$ are shown to be zero. The way of dealing with the quadratic divergences proportional to $M_Z^2/M^3$ in $H \to \gamma Z$ has subtle implication on the employment on the Feynman rules especially when those rules can lead to high level divergences. So calculation without integration on all the $\delta$ functions until have to is a more proper or maybe necessary way of the employment of the Feynman rules.Comment: 1 figure, 34 pages (updated

Effect of High Se and Co Alfalfa Forage on Animal Production

Total and available selenium (Se) and cobalt (Co) concentrations are low in Chinese soils, especially those found in mainly in temperate humid sub-humid conditions in the northeast to the southwest band across China (Tan et al. 2002). The levels of Se and Co are marginally deficit in the brown soil of the Yellow River region which causes lower production level and quality in forage and crop plants. Application of Se and Co fertilizers to arable lands is essential to produce high Se and Co forages. Henan is a Province where produce high-quality grass forages are used to support dairy farming. The province is mainly spread along the Yellow River where soils are sandy and deficient in Se and Co (Lu et al. 2003). Se deficiency in forages not only limits livestock production, but also affects the quality and safety of food products (Rotruck et al. 2003). Since rabbits and dairy cows are especially sensitive to low Se levels in feed, we chose these as our test animals. The objective of this study was to analyze effect of high Se and Co alfalfa forage on animal production and feed conversion efficiency in order to establish a set of effective technical ways to solve trace element gaps of animal diets, i.e. by basal fertilization of Se and Co fertilizers in soil. This study was conducted as a series of field trials and animal experiments from 2007 to 2008

Effects of Se and Co Combined Fertilizer on Production of Alfalfa

Selenium(Se) and cobalt (Co) are important essential trace elements for forage and animal production (Yang et al. 1998, Arvy 1993). The supplementation of Se in animal diet significantly increases Se-Glutathione peroxidase (GSH-Px ) activities in the liver, testes, spermatozoa and seminal plasma (Abdelrahman et al.1998), Selenium is also a key component of a number of functional seleno-proteins. GSH-Px is the best characterized of the family of selenoproteins. In Henan Province, the fine grass and green milk production zones are mainly distributed along the riverbank of the Yellow River where soils are sandy and sterile with lower Se and Co contents (Lu et al. 2003). Deficiency of Se and Co in soils affects local forage and animal production level, as well as the qualities and securities of fodder and animal products (Rotruck et al. 2003). This experiment was carried out to determine the impacts of the application combined Se and Co on the quality of alfalfa hay

Vehicular Fog Computing Enabled Real-time Collision Warning via Trajectory Calibration

Vehicular fog computing (VFC) has been envisioned as a promising paradigm for enabling a variety of emerging intelligent transportation systems (ITS). However, due to inevitable as well as non-negligible issues in wireless communication, including transmission latency and packet loss, it is still challenging in implementing safety-critical applications, such as real-time collision warning in vehicular networks. In this paper, we present a vehicular fog computing architecture, aiming at supporting effective and real-time collision warning by offloading computation and communication overheads to distributed fog nodes. With the system architecture, we further propose a trajectory calibration based collision warning (TCCW) algorithm along with tailored communication protocols. Specifically, an application-layer vehicular-to-infrastructure (V2I) communication delay is fitted by the Stable distribution with real-world field testing data. Then, a packet loss detection mechanism is designed. Finally, TCCW calibrates real-time vehicle trajectories based on received vehicle status including GPS coordinates, velocity, acceleration, heading direction, as well as the estimation of communication delay and the detection of packet loss. For performance evaluation, we build the simulation model and implement conventional solutions including cloud-based warning and fog-based warning without calibration for comparison. Real-vehicle trajectories are extracted as the input, and the simulation results demonstrate that the effectiveness of TCCW in terms of the highest precision and recall in a wide range of scenarios

Binding of pRNA to the N-terminal 14 amino acids of connector protein of bacteriophage phi29

During assembly, bacterial virus phi29 utilizes a motor to insert genomic DNA into a preformed protein shell called the procapsid. The motor contains one twelve-subunit connector with a 3.6 nm central channel for DNA transportation, six viral-encoded RNA (packaging RNA or pRNA) and a protein, gp16, with unknown stoichiometry. Recent DNA-packaging models proposed that the 5-fold procapsid vertexes and 12-fold connector (or the hexameric pRNA ring) represented a symmetry mismatch enabling production of a force to drive a rotation motor to translocate and compress DNA. There was a discrepancy regarding the location of the foothold for the pRNA. One model [C. Chen and P. Guo (1997) J. Virol., 71, 3864–3871] suggested that the foothold for pRNA was the connector and that the pRNA–connector complex was part of the rotor. However, one other model suggested that the foothold for pRNA was the 5-fold vertex of the capsid protein and that pRNA was the stator. To elucidate the mechanism of phi29 DNA packaging, it is critical to confirm whether pRNA binds to the 5-fold vertex of the capsid protein or to the 12-fold symmetrical connector. Here, we used both purified connector and purified procapsid for binding studies with in vitro transcribed pRNA. Specific binding of pRNA to the connector in the procapsid was found by photoaffinity crosslinking. Removal of the N-terminal 14 amino acids of the gp10 protein by proteolytic cleavage resulted in undetectable binding of pRNA to either the connector or the procapsid, as investigated by agarose gel electrophoresis, SDS–PAGE, sucrose gradient sedimentation and N-terminal peptide sequencing. It is therefore concluded that pRNA bound to the 12-fold symmetrical connector to form a pRNA–connector complex and that the foothold for pRNA is the connector but not the capsid protein