The PANDA collaboration at FAIR, Germany, will employ antiproton annihilations to investigate yet undiscovered charm-mesons and glueballs aiming to unravel the origin of hadronic masses. A ...multi-purpose detector for tracking, calorimetry and particle identification is presently being developed to run at high luminosities providing up to 2.107 interactions/s. A trigger-less data-acquisition system will be employed with sub-detectors continuously providing data from incoming physics events. This paper describes readout electronics and the treatment of the digitised preamplifier signal for the Electromagnetic Calorimeter. The use of a Sampling ADC in the readout allows to achieve the design goals, namely a large dynamic range from 1 MeV to 10 GeV, a count-rate dependent low trigger threshold of about 1-3 MeV, and a time resolution better than 1 ns.
Exclusive measurements of the reaction pp -> d pi(+)pi(0) have been carried out at T-p = 1.1 GeV at the CELSIUS storage ring using the WASA detector. The isovector pi(+)pi(0) channel exhibits no ...enhancement at low invariant pi pi masses, i.e. no ABC effect. Therefore this most basic isovector double-pionic fusion reaction qualifies as an ideal test case for the conventional t-channel Delta Delta excitation process. Indeed, the obtained differential distributions reveal the conventional t-channel Delta Delta mechanism as the appropriate reaction process, which also accounts for the observed energy dependence of the total cross section.
The cross section for the pd→ 3 Heηπ 0 reaction has been measured at a beam energy of 1450 MeV using the WASA detector at the CELSIUS storage ring and detecting one 3 He and four photons from the ...decays of the two mesons. The data indicate that the production mechanism involves the formation of the Δ(1232) isobar. Although the beam energy does not allow the full peak of this resonance to be seen, the invariant masses of all three pairs of final particles are well reproduce dby a phase space Monte Carlo simulation weighted with the p-wave factor of the square of the π 0 momentum in the 3 He π 0 system.
We present a combined analysis of the observations of the gravitational microlensing event OGLE-2015-BLG-0479 taken both from the ground and by the {\it Spitzer Space Telescope}. The light curves ...seen from the ground and from space exhibit a time offset of \(\sim 13\) days between the caustic spikes, indicating that the relative lens-source positions seen from the two places are displaced by parallax effects. From modeling the light curves, we measure the space-based microlens parallax. Combined with the angular Einstein radius measured by analyzing the caustic crossings, we determine the mass and distance of the lens. We find that the lens is a binary composed of two G-type stars with masses \(\sim 1.0\ M_\odot\) and \(\sim 0.9\ M_\odot\) located at a distance \(\sim 3\) kpc. In addition, we are able to constrain the complete orbital parameters of the lens thanks to the precise measurement of the microlens parallax derived from the joint analysis. In contrast to the binary event OGLE-2014-BLG-1050, which was also observed by {\it Spitzer}, we find that the interpretation of OGLE-2015-BLG-0479 does not suffer from the degeneracy between \((\pm,\pm)\) and \((\pm,\mp)\) solutions, confirming that the four-fold parallax degeneracy in single-lens events collapses into the two-fold degeneracy for the general case of binary-lens events. The location of the blend in the color-magnitude diagram is consistent with the lens properties, suggesting that the blend is the lens itself. The blend is bright enough for spectroscopy and thus this possibility can be checked from future follow-up observations.
To move one step forward toward a Galactic distribution of planets, we present the first planet sensitivity analysis for microlensing events with simultaneous observations from space and the ground. ...We present this analysis for two such events, OGLE-2014-BLG-0939 and OGLE-2014-BLG-0124, which both show substantial planet sensitivity even though neither of them reached high magnification. This suggests that an ensemble of low to moderate magnification events can also yield significant planet sensitivity and therefore probability to detect planets. The implications of our results to the ongoing and future space-based microlensing experiments to measure the Galactic distribution of planets are discussed.
Adventitial cysts of the popliteal artery are rare. Their pathogenesis is debated. In one of the two cases reported here, there was a communication between the arterial cyst and the articulation of ...the knee. This supports the embryonic theory that the articular synovium and adventitial cysts have the same mesenchymal origins. Treatment is surgical, with simple evacuation of the contents of the cyst in uncomplicated cases, excision and reconstruction in the others.
The reaction pd -> He-3 eta at threshold was used to provide a clean source of eta mesons for decay studies with the WASA detector at CELSIUS. The branching ratio of the decay eta -> ...pi(+)pi(-)e(+)e(-) is measured to be (4.3 +/- 1.3 +/- 0.4) x 10(-4).
Exclusive measurements of the reactions pd -> He-3 pi(+)7 pi(-) and pd -> He-3 pi(0)pi(0) have been carried out at T-p = 0.893 GeV at the CELSIUS storage ring using the WASA detector. The ...pi(+)pi(-) channel evidences a pronounced enhancement at low invariant pi pi masses-as anticipated from previous inclusive measurements of the ABC effect. This enhancement is seen to be even much larger in the isoscalar pi(0)pi(0) channel. The differential distributions prove this enhancement to be of scalar-isoscalar nature. Delta Delta calculations give a good description of the data, if a boundstate condition is imposed for the intermediate Delta Delta system.
A case of post-traumatic hepaticoportal arteriovenous fistula between common hepatic artery and portal vein is reported. This localization of the lesion is exceptional, and early, marked clinical ...manifestations allow rapid diagnosis and treatment before the development of a portal hypertension.
A review of a homogeneous series of 25 cases of duodenopancreatic injuries emphasizes the serious nature of the lesions operated upon at the acute pancreatitis stage. An early diagnosis of these ...duodenopancreatic lesions is essential since they are often included in the context of multiple injuries. Principal diagnostic difficulties arise in lesions due to contusion without associated intra-abdominal injuries. In these cases ultrasound and CT scan imaging provide valuable data, particularly the latter exploration which is 89% reliable in demonstrating pancreatic morphology. Treatment differs as a function of presence of isolated or combined duodenal and pancreatic lesions and of lesional type. It should be as conservative as possible, although exeresis for lesions of body and tail of pancreas is currently performed more frequently.
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