Momentum, track angle and impact parameter resolution are key performance parameters that tracking detectors are optimised for. This report presents analytic expressions for the resolution of these ...parameters for equal and equidistant tracking layers. The expressions for the contribution from position resolution are based on the Gluckstern formulae and are well established. The expressions for the contribution from multiple scattering using optimum weights are discussed in detail.
We report the first observation of the spontaneous polarization of Λ and Λover ¯ hyperons transverse to the production plane in e^{+}e^{-} annihilation, which is attributed to the effect arising from ...a polarizing fragmentation function. For inclusive Λ/Λover ¯ production, we also report results with subtracted feed-down contributions from Σ^{0} and charm. This measurement uses a dataset of 800.4 fb^{-1} collected by the Belle experiment at or near a center-of-mass energy of 10.58 GeV. We observe a significant polarization that rises with the fractional energy carried by the Λ/Λover ¯ hyperon.
We report the first observation of the double strange baryon Ξ(1620)0 in its decay to Ξ−π+ via Ξ+c → Ξ−π+π+ decays based on a 980 fb−1 data sample collected with the Belle detector at the KEKB ...asymmetric-energy e+e− collider. The mass and width are measured to be 1610.4 ± 6.0(stat)+6.1−4.2(syst) MeV /c2 and 59.9 ± 4.8(stat)+2.8−7.1(syst) MeV, respectively. We obtain 4.0σ evidence of the Ξ(1690)0 with the same data sample. These results shed light on the structure of hyperon resonances with strangeness S = −2
We report the results of a search for the rare, purely leptonic decay B−→μ−ν¯μ performed with a 711 fb−1 data sample that contains 772×106 BB¯ pairs, collected near the ϒ(4S) resonance with the ...Belle detector at the KEKB asymmetric-energy e+e− collider. The signal events are selected based on the presence of a high momentum muon and the topology of the rest of the event showing properties of a generic B-meson decay, as well as the missing energy and momentum being consistent with the hypothesis of a neutrino from the signal decay. We find a 2.4 standard deviation excess above background including systematic uncertainties, which corresponds to a branching fraction of B(B−→μ−ν¯μ)=(6.46±2.22±1.60)×10−7 or a frequentist 90% confidence level interval on the B−→μ−ν¯μ branching fraction of 2.9,10.7×10−7.
The paper is based on the data of the 2009 DEPFET beam test at CERN SPS. The beam test used beams of pions and electrons with energies between 40 and 120
GeV, and the sensors tested were prototypes ...with thickness of
450
μ
m
and pixel pitch between 20 and
32
μ
m
. Intrinsic resolutions of the detectors are calculated by disentangling the contributions of measurement errors and multiple scattering in tracking residuals. Properties of the intrinsic resolution estimates and factors that influence them are discussed. For the DEPFET detectors in the beam test, the calculation yields intrinsic resolutions of
≈
1
μ
m
, with a typical accuracy of
0.1
μ
m
. Bias scan, angle scan, and energy scan are used as example studies to show that the intrinsic resolutions are a useful tool in studies of detector properties. With sufficiently precise telescopes, detailed resolution maps can be constructed and used to study and optimize detector performance.
SiLC R&D: Design, present status and perspectives Lozano, M.; Orava, R.; van Remortel, N. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
09/2007, Letnik:
579, Številka:
2
Journal Article
Recenzirano
Odprti dostop
This paper briefly describes the main R&D objectives that are undertaken within the international R&D collaboration SiLC aiming to build the next generation of silicon tracking devices especially in ...the case of the ILC. Firstly, motivation to use silicon detectors in the tracker is explained. Then basic aspects of the design and solutions proposed are described (sensors, front-end electronics, mechanics, alignment). First results from the lab and beam test of the front-end chips and module prototypes built are shown.
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