Fermilab experiment E835 has measured the cross section for the reaction p̄p→e+e− at s=11.63, 12.43, 14.40 and 18.22 GeV2. From the analysis of the 66 observed events new high-precision measurements ...of the proton magnetic form factor are obtained.
CDF Run II silicon vertex detector annealing study Stancari, M.; Knoepfel, K.; Behari, S. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2014, Letnik:
743
Journal Article
Recenzirano
Odprti dostop
Between Run II commissioning in early 2001 and the end of operations in September 2011, the Tevatron collider delivered 12fb−1 of pp¯ collisions at s=1.96TeV to the Collider Detector at Fermilab ...(CDF). During that time, the CDF silicon vertex detector was subject to radiation doses of up to 12Mrad. After the end of operations, the silicon detector was annealed for 24days at 18°C. In this paper, we present a measurement of the change in the bias currents for a subset of sensors during the annealing period. We also introduce a novel method for monitoring the depletion voltage throughout the annealing period. The observed bias current evolution can be characterized by a falling exponential term with time constant τI=17.88±0.36(stat.)±0.25(syst.) days. We observe an average decrease of (27±3)% in the depletion voltage, whose evolution can similarly be described by an exponential time constant of τV=6.21±0.21days. These results are consistent with the Hamburg model within the measurement uncertainties.
.
The spin-exchange collision cross-section for hydrogen atoms has been measured for the first time in the low temperature range 40–100 K by using the polarized hydrogen gas target of the HERMES ...experiment at DESY (Hamburg, Germany). The results agree with a previous measurement in the overlapping temperature region 80–100 K, while seem to hint an increasing behaviour with temperature in the region 50–80 K.
PDF
