The lead-glass electromagnetic calorimeter for the SELEX experiment Balatz, M.Y.; Cooper, P.S.; Davidenko, G.V. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
06/2005, Letnik:
545, Številka:
1
Journal Article
Recenzirano
Odprti dostop
A large-acceptance, highly segmented electromagnetic lead-glass calorimeter for Experiment E781 (SELEX) at Fermi National Acceleration Laboratory was designed and built. This detector has been used ...to reconstruct photons and electrons with energies ranging from a few GeV up to 500
GeV in the collisions of the 600
GeV
Σ
-
hyperons,
π
mesons and protons with the target nucleons. The design, calibration and performance of the calorimeter are described. Energy resolution and position resolution are assessed using both calibration electron beams and
π
0
mesons reconstructed in 600
GeV hadron–hadron interactions. The performance of the calorimeter in selecting resonant states that involve photons is demonstrated.
A method for detecting the transition ν
μ→ν
τ in long-baseline accelerator experiments, that consists in comparing the far-to-near ratios of the spectra of quasielastic CC events generated by high- ...and low-energy beams of muon neutrinos, is proposed. The test may be accessible to big water Cherenkov detectors and iron-scintillator calorimeters, and is limited by statistics rather than systematics. In the NuMI program with the MINOS detector, only the Δ
m
2 values above some
4×10
−3
eV
2
can be probed.
A conceptual scheme of a hybrid-emulsion spectrometer for investigating various channels of neutrino oscillations is proposed. The design emphasizes detection of τ leptons by detached vertices, ...reliable identification of electrons, and good spectrometry for all charged particles and photons. A distributed target is formed by layers of low-
Z material, emulsion–plastic–emulsion sheets, and air gaps in which τ decays are detected. The tracks of charged secondaries, including electrons, are momentum-analyzed by curvature in magnetic field using hits in successive thin layers of emulsion. The τ leptons are efficiently detected in all major decay channels, including
τ
−→
e
−
ν
ν
̄
. The performance of a model spectrometer, that contains 3 t of nuclear emulsion and 20 t of passive material, is estimated for different experimental environments. When irradiated by the ν
μ beam of a proton accelerator over a medium baseline of
〈L/E
ν
〉∼1
km/
GeV
, the spectrometer will efficiently detect either the ν
μ→ν
τ or the ν
μ→ν
e transitions in the mass-difference region of
Δm
2∼1
eV
2
, as suggested by the results of LSND. When exposed to the neutrino beam of a muon storage ring over a long baseline of 〈
L/
E
ν〉∼10–
20
km/
GeV
, the model detector will efficiently probe the entire pattern of neutrino oscillations in the region Δ
m
2∼10
−2–
10
−3
eV
2
, as suggested by the data on atmospheric neutrinos.
PDF