Double Resonance in Dalitz Plot of M(pLambda)-M(KLambda) in DISTO Data on p+p rightarrow p+Lambda+K+ at 2.85 GeV

The X(2265) resonance was previously observed in DISTO data of p+p rightarrow p+Lambda+K+ at 2.85 GeV on an attempt of searching for the kaonic nuclear state K-pp rightarrow p + Lambda. In the present paper we report an additional finding, namely, a double resonance type phenomena, not only with a peak at M(pLambda) = 2265 MeV/c2 but also a broad bump at M(K+ Lambda) ~ 1700 MeV/c2. This "double-resonance" zone is expressed as XY(2265, 1700). The latter bump may result from nearby nucleon resonances, typically N*(1710), as well as by attractive K - Lambda final-state interaction. We point out that this double resonance XY(2265, 1700) as seen in DISTO at 2.85 GeV cannot be populated kinematically in a HADES experiment at 3.5 GeV.Comment: 4 pages, 3 figures, HYP2015 conferenc

Monte Carlo simulation of events with Drell-Yan lepton pairs from antiproton-proton collisions: the fully polarized case

In this paper, we extend the study of Drell-Yan processes with antiproton beams already presented in a previous work. We consider the fully polarized $\bar{p}^\uparrow p^\uparrow \to \mu^+ \mu^- X$ process, because this is the simplest scenario for extracting the transverse spin distribution of quarks, or transversity, which is the missing piece to complete the knowledge of the nucleon spin structure at leading twist. We perform Monte Carlo simulations for transversely polarized antiproton and proton beams colliding at a center-of-mass energy of interest for the future HESR at GSI. The goal is to possibly establish feasibility conditions for an unambiguous extraction of the transversity from data on double spin asymmetries.Comment: Produced in RevTeX 4, 10 figures in .eps forma

Monte Carlo simulation of single spin asymmetries in pion-proton collisions

We present Monte Carlo simulations of both the Sivers and the Boer-Mulders effects in the polarized Drell-Yan $\pi^\pm p^\uparrow \to \mu^+ \mu^- X$ process at the center-of-mass energy $\sqrt{s} \sim 14$ GeV reachable at COMPASS with pion beams of energy 100 GeV. For the Sivers effect, we adopt two different parametrizations for the Sivers function to explore the statistical accuracy required to extract unambiguous information on this parton density. In particular, we verify the possibility of checking its predicted sign change between Semi-Inclusive Deep-Inelastic Scattering (SIDIS) and Drell-Yan processes, a crucial test of nonperturbative QCD. For the Boer-Mulders effect, because of the lack of parametrizations we can make only guesses. The goal is to explore the possibility of extracting information on the transversity distribution, the missing piece necessary to complete the knowledge of the nucleon spin structure at leading twist, and the Boer-Mulders function, which is related to the long-standing problem of the violation of the Lam-Tung sum rule in the unpolarized Drell-Yan cross section.Comment: RevTeX, 13 pages, 7 figures included in .eps forma

An Innovative Harmonic Radar to Track Flying Insects: the Case of Vespa velutina

Over the last 30 years, harmonic radars have been effective only in tracking insects flying at low altitude and over flat terrain. We developed an innovative harmonic radar, implementing the most advanced radar techniques, which covers a large field of view in elevation (with an angular aperture of about 24°) and can track insects up to a range of 500 m. We show all the components of this new harmonic radar and its first application, the tracking of Vespa velutina (yellow-legged Asian hornet). This is an invasive species which, although indigenous to South-East Asia, is spreading quickly to other regions of the world. Because of its fast diffusion and the serious threat it poses to both honeybee colonies and to humans, control measures are mandatory. When equipped with a small passive transponder, this radar system can track the flight trajectory of insects and locate nests to be destroyed. This tool has potential not only for monitoring V. velutina but also for tracking other larger insects and small size vertebrates

Effects of azimuth-symmetric acceptance cutoffs on the measured asymmetry in unpolarized Drell-Yan fixed target experiments

Fixed-target unpolarized Drell-Yan experiments often feature an acceptance depending on the polar angle of the lepton tracks in the laboratory frame. Typically leptons are detected in a defined angular range, with a dead zone in the forward region. If the cutoffs imposed by the angular acceptance are independent of the azimuth, at first sight they do not appear dangerous for a measurement of the cos(2\phi)-asymmetry, relevant because of its association with the violation of the Lam-Tung rule and with the Boer-Mulders function. On the contrary, direct simulations show that up to 10 percent asymmetries are produced by these cutoffs. These artificial asymmetries present qualitative features that allow them to mimic the physical ones. They introduce some model-dependence in the measurements of the cos(2\phi)-asymmetry, since a precise reconstruction of the acceptance in the Collins-Soper frame requires a Monte Carlo simulation, that in turn requires some detailed physical input to generate event distributions. Although experiments in the eighties seem to have been aware of this problem, the possibility of using the Boer-Mulders function as an input parameter in the extraction of Transversity has much increased the requirements of precision on this measurement. Our simulations show that the safest approach to these measurements is a strong cutoff on the Collins-Soper polar angle. This reduces statistics, but does not necessarily decrease the precision in a measurement of the Boer-Mulders function.Comment: 13 pages, 14 figure

An harmonic radar prototype for insect tracking in harsh environments

Harmonic entomological radars have been used in the last decades to track small and lightweight passive tags carried by various insects, usually flying at low altitude and over flat terrain. Despite being exploited in many applications, not a lot of progress was achieved in terms of performances over the years. This paper reviews the research work done in this topic throughout the European LIFE project STOPVESPA, from 2015 to 2019. The main objective of LIFE STOPVESPA was to contain the invasive Asian hornet (Vespa velutina) and prevent it from further invading Italy. Among the foreseen activities, a new harmonic radar has been developed as an effective tool to locate the hornets nests to be destroyed. A preliminary prototype, based on a magnetron generator, was tested in 2015, showing a detection range of about 125 m. A first upgrade of this prototype was released in 2016, allowing to increase the detection range up to 150 m. A new approach, based on a solid state power amplifier and a digitally modulated signal, was then adopted for the second prototype developed in 2017 and extensively run in 2018; the detection range raised to 500 m. A last engineered prototype was eventually built for the 2019 summer campaign with additional improvements. This tool has been extensively validated over the last years with the Asian hornet but it has potential for tracking and monitoring many other flying insects