Hybrid pixel detector development for the linear collider Vertex Tracker Battaglia, M; Borghi, S; Campagnolo, R ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
11/2001, Letnik:
473, Številka:
1
Journal Article
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In order to fully exploit the physics potential of the future high energy e
+e
− linear collider, a Vertex Tracker able to provide particle track extrapolation with very high resolution is needed. ...Hybrid Si pixel sensors constitute an attractive technology due to their fast read-out capabilities and radiation hardness. A novel pixel detector layout with interleaved cells has been developed to improve the single point resolution. Results of the characterisation of the first processed prototypes by electrostatic measurements and charge collection studies are discussed.
To fully exploit the physics potential of future high-energy e/sup +/e/sup /linear colliders, a vertex detector providing high-resolution track reconstruction is required. Hybrid silicon pixel ...detectors are an attractive option for the sensor technology due to their readout speed and radiation hardness but have been so far limited by the achievable single-point resolution. A novel layout of a hybrid pixel sensor with interleaved cells to improve the spatial resolution has been developed. The characterization of the first processed prototypes is reported.
We report a precise measurement of the masses of the Ξc(2645) and Ξc(2815) baryons using a data sample of 414 fb−1 collected by the Belle Collaboration at the KEKB e+e− collider. The states ...Ξc(2645)0,+ are observed in the Ξc+,0π−,+ decay modes, while the Ξc(2815)0,+ are reconstructed in the Ξc(2645)+,0π−,+ decay modes. The following mass splittings are determined: mΞc(2645)+−mΞc(2645)0=(−0.1±0.3(stat)±0.6(syst)) MeV/c2 and mΞc(2815)+−mΞc(2815)0=(−3.4±1.9(stat)±0.9(syst)) MeV/c2 with a much better precision than the current world averages. We also observe a new decay mode, Ξc(2980)0,+→Ξc(2645)+,0π−,+.
The adhesion capacity of desmosomal cadherins was studied by expressing desmogleins and desmocollins along their related protein plakoglobin in normal nonadherent L cell fibroblasts. The desmoplakin ...(DP) connection between cadherins and plakoglobin complex was also analyzed and tested since DP was needed to adhere intermediate filament with desmosome. The cadherins and plakoglobins developed a complex linked with the DP N-terminus capable of bundling transmembrane desmosomal cadherin complexes.
We report measurements of partial branching fractions of inclusive charmless semileptonic B-meson decays at the endpoint of the electron momentum spectrum. The measurements are made in six ...overlapping momentum intervals that have lower bounds ranging from 1.9 to 2.4 GeV/c and a common upper bound of 2.6 GeV/c, as measured in the centre of mass frame. The results are based on a sample of 29 million BB¯ pairs, accumulated by the Belle detector at the KEKB asymmetric e+e− collider operating on the ϒ(4S) resonance. In the momentum interval ranging from 1.9 to 2.6 GeV/c we measure the partial branching fraction ΔB(B→Xueνe)=(8.47±0.37±1.53)×10−4, where the first error is statistical and the second is systematic. A prediction of the partial rate R=(21.69±3.62−1.98+2.18)|Vub|2 ps−1 in this momentum interval based on theory is calculated with input HQET parameters that have been derived from Belle's measurement of the B→Xsγ photon energy spectrum, where the first error is due to the uncertainty on HQET parameters and the second error is from theory. Using both ΔB(B→Xueνe) and R we find |Vub|=(5.08±0.47±0.42−0.23+0.26)×10−3, where the first error is from the partial branching fraction, and the second and third errors are from uncertainties in R.
We report measurements of charmonia produced in two-photon collisions and decaying to four-meson final states, where the meson is either a charged pion or a charged kaon. The analysis is based on a ...395 fb
-1
data sample accumulated with the Belle detector at the KEKB electron–positron collider. We observe signals for the three C-even charmonia η
c
(1S), χ
c0
(1P) and χ
c2
(1P) in the π
+
π
-
π
+
π
-
, K
+
K
-
π
+
π
-
and K
+
K
-
K
+
K
-
decay modes. No clear signals for η
c
(2S) production are found in these decay modes. We have also studied resonant structures in charmonium decays to two-body intermediate meson resonances. We report the products of the two-photon decay width and the branching fractions,
, for each of the charmonium decay modes.
We search for lepton flavor and lepton number violating τ decays into a lepton (ℓ=electron or muon) and two charged mesons (h,h′=π± or K±), τ−→ℓ−h+h′− and τ−→ℓ+h−h′−, using 671 fb−1 of data collected ...with the Belle detector at the KEKB asymmetric-energy e+e− collider. We obtain 90% C.L. upper limits on the branching fractions in the range (4.4–8.8)×10−8 for τ→ehh′, and (3.3–16)×10−8 for τ→μhh′ processes. These results improve upon previously published upper limits by factors between 1.6 to 8.8.
A high precision study of the process γγ→pp¯ has been performed using a data sample of 89 fb−1 collected with the Belle detector at the KEKB e+e− collider. The cross section of pp¯ production has ...been measured at two-photon center-of-mass (c.m.) energies between 2.025 and 4.0 GeV and in the c.m. angular range of |cosθ∗|<0.6. Production of γγ→ηc→pp¯ is observed and the product of the two-photon width of the ηc and its branching ratio to pp¯ is determined.
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