9 Symmetry Violations and Quark Flavour Physics
555
Muon
Veto
K Beams
L
Vacuum Window
Analysis Magnet
Muon
Filter
Trigger
Hodoscopes
with Lead Wall
Hadron Veto
Chambers
Drift
Regenerator
Distance from Target (m)
120
140
160
180
20 cm
CsI
Photon Veto Detectors
Vacuum Decay Region
Fig. 9.9 kTeV beam and detector
These blocks were viewed by photomultiplier tubes to reject inelastically or quasielastically scattered kaons.
The evacuated decay volume extended over 40 m, or about 7 K S mean lifetimes
at 100 GeV/c, followed by the first drift chamber. The analysis magnet was located
between the second and the third drift chamber. Each of the four drift chambers had
two horizontal and two vertical planes of sense wires. The typical single-hit position
resolution of the drift chambers was about 110 μm in either direction, which lead
to a mean mass resolution of 2.2 MeV for the reconstructed kaon mass obtained
from the π + π − decay mode. The momentum resolution for a charged particle was
σ p /p = 0.17% ⊕ 0.0071% × p (in GeV/c).
The four photons from the 2π 0 were detected in an electromagnetic calorimeter
made of pure cesium iodide. The calorimeter consisted of 3100 blocks arranged in
a square array of 1.9 m side length. The blocks had two sizes: 2.5 × 2.5 cm 2 in
the central region and 5 × 5 cm 2 in the outer region. All blocks are 50 cm, or ∼27
radiation lengths, long. Two 15 cm square holes allowed the passage of the K L and
the K S beam through the calorimeter. The calorimeter had an energy resolution of
σ E /E = 2%/
√
E ⊕ 0.4% (E in GeV). The average position resolution for electrons
was about 1.2 mm for clusters in the smaller crystals and 2.4 mm for the larger
crystals.
9.5.4.7 CPLEAR
In contrast to the detectors described in the previous sections, the CPLEAR detector
measured decays from kaons produced in ¯
pp annihilations at rest obtained from
555
Muon
Veto
K Beams
L
Vacuum Window
Analysis Magnet
Muon
Filter
Trigger
Hodoscopes
with Lead Wall
Hadron Veto
Chambers
Drift
Regenerator
Distance from Target (m)
120
140
160
180
20 cm
CsI
Photon Veto Detectors
Vacuum Decay Region
Fig. 9.9 kTeV beam and detector
These blocks were viewed by photomultiplier tubes to reject inelastically or quasielastically scattered kaons.
The evacuated decay volume extended over 40 m, or about 7 K S mean lifetimes
at 100 GeV/c, followed by the first drift chamber. The analysis magnet was located
between the second and the third drift chamber. Each of the four drift chambers had
two horizontal and two vertical planes of sense wires. The typical single-hit position
resolution of the drift chambers was about 110 μm in either direction, which lead
to a mean mass resolution of 2.2 MeV for the reconstructed kaon mass obtained
from the π + π − decay mode. The momentum resolution for a charged particle was
σ p /p = 0.17% ⊕ 0.0071% × p (in GeV/c).
The four photons from the 2π 0 were detected in an electromagnetic calorimeter
made of pure cesium iodide. The calorimeter consisted of 3100 blocks arranged in
a square array of 1.9 m side length. The blocks had two sizes: 2.5 × 2.5 cm 2 in
the central region and 5 × 5 cm 2 in the outer region. All blocks are 50 cm, or ∼27
radiation lengths, long. Two 15 cm square holes allowed the passage of the K L and
the K S beam through the calorimeter. The calorimeter had an energy resolution of
σ E /E = 2%/
√
E ⊕ 0.4% (E in GeV). The average position resolution for electrons
was about 1.2 mm for clusters in the smaller crystals and 2.4 mm for the larger
crystals.
9.5.4.7 CPLEAR
In contrast to the detectors described in the previous sections, the CPLEAR detector
measured decays from kaons produced in ¯
pp annihilations at rest obtained from