The DIRC particle identification system for the BaBar experiment Aleksan, R.; Amerman, L.; Aston, D. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
02/2005, Letnik:
538, Številka:
1-3
Journal Article
Recenzirano
Odprti dostop
A new type of ring-imaging Cherenkov detector is being used for hadronic particle identification in the BABAR experiment at the SLAC B Factory (PEP-II). This detector is called DIRC, an acronym for ...Detection of Internally Reflected Cherenkov (Light). This paper will discuss the construction, operation and performance of the BABAR DIRC in detail.
Test beam results for an endcap electromagnetic calorimeter for the SSC Abrams, G.S.; Ashmanskas, W.; Bintinger, D. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
05/1997, Letnik:
390, Številka:
1
Journal Article
Recenzirano
Odprti dostop
We have tested a calorimeter test beam module intended to simulate the endcap electromagnetic calorimeter of the Solenoidal Detector Collaboration (SDC) experiment at the SSC. The test module is ...manufactured from scintillating tiles and is read out via 1 mm diameter wavelength shifting fibers with shower sampling at ∼ 1 radiation length intervals. The results of test beam calibration show that the calorimeter is linear to within 1% and has a resolution of (19.5 ± 0.1)%/√
E⊕(0.47%±0.05)% for energies up to 200 GeV. Test beam data show that non-uniform, longitudinal radiation damage to the calorimeter (up to ∼ 50% light loss at shower maximum) can be corrected, and the original linearity of the calorimeter can be recovered with only a small degradation of resolution. A “pre-shower detector” improves the charged
π rejection by a factor of 2–3 at an electron detection efficiency greater than 97.5 ± 0.3%.
The DIRC is a totally internally reflecting Cherenkov imaging detector proposed for particle identification at the asymmetric e/sup +/e/sup -/ B factories. First test results from a conceptual ...prototype using cosmic muons are reported. The photo-electron yield and the single Cherenkov photon resolution at various track dip angles and positions along the radiator bar have been measured. The results are consistent with estimates and Monte-Carlo simulations.< >
Performance of the BaBar-DIRC Schwiening, J.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment,
11/2005, Letnik:
553, Številka:
1-2
Journal Article, Conference Proceeding
Recenzirano
Odprti dostop
A new type of ring-imaging Cherenkov detector is being used for hadronic particle identification in the BABAR experiment at the SLAC B Factory (PEP-II). This detector is called DIRC, an acronym for ...Detection of Internally Reflected Cherenkov (Light). This paper describes the performance of the DIRC during the first 5 years of operation.
We present measurements of the branching fractions for the three-body decays B 0 → D ( * ) ∓ K 0 π ± and their resonant submodes B 0 → D ( * ) ∓ K * ± using a sample of approximately 88 × 10 6 B ¯¯¯ ...B pairs collected by the BABAR detector at the SLAC PEP-II asymmetric energy storage ring. We measure: B ( B 0 → D ∓ K 0 π ± ) = ( 4.9 ± 0.7 stat ± 0.5 syst ) × 10 − 4 , B ( B 0 → D * ∓ K 0 π ± ) = ( 3.0 ± 0.7 stat ± 0.3 syst ) × 10 − 4 , B ( B 0 → D ∓ K * ± ) = ( 4.6 ± 0.6 stat ± 0.5 syst ) × 10 − 4 , B ( B 0 → D * ∓ K * ± ) = ( 3.2 ± 0.6 stat ± 0.3 syst ) × 10 − 4 . From these measurements we determine the fractions of resonant events to be f ( B 0 → D ∓ K * ± ) = 0.63 ± 0.08 stat ± 0.04 syst and f ( B 0 → D * ∓ K * ± ) = 0.72 ± 0.14 stat ± 0.05 syst .
We study initial-state radiation events, e + e − → γ ISR π + π − J / ψ , with data collected with the BABAR detector. We observe an accumulation of events near 4.26 GeV / c 2 in the ...invariant-mass spectrum of π + π − J / ψ . Fits to the mass spectrum indicate that a broad resonance with a mass of about 4.26 GeV / c 2 is required to describe the observed structure. The presence of additional narrow resonances cannot be excluded. The fitted width of the broad resonance is 50 to 90 MeV / c 2 , depending on the fit hypothesis.
We report on a measurement of the Cabibbo-Kobayashi-Maskawa C P -violating phase γ through a Dalitz analysis of neutral D decays to K 0 S π − π + in the processes B ∓ → D ( * ) K ∓ , D ∗ → D π 0 , D ...γ . Using a sample of 227 × 10 6 B ¯¯¯ B pairs collected by the BABAR detector, we measure the amplitude ratios r B = 0.12 ± 0.08 ± 0.03 ± 0.04 and r ∗ B = 0.17 ± 0.10 ± 0.03 ± 0.03 , the relative strong phases δ B = ( 104 ± 45 + 17 + 16 − 21 − 24 ) ° and δ ∗ B = ( − 64 ± 41 + 14 − 12 ± 15 ) ° between the amplitudes A ( B − → ¯¯¯ D ( * ) 0 K − ) and A ( B − → D ( * ) 0 K − ) , and γ = ( 70 ± 31 + 12 + 14 − 10 − 11 ) ° . The first error is statistical, the second is the experimental systematic uncertainty, and the third reflects the Dalitz model uncertainty. The results for the strong and weak phases have a twofold ambiguity.
Production and decay of Ξ0c at BABAR AUBERT, B; BARATE, R; PALANO, A ...
Physical review letters,
09/2005, Letnik:
95, Številka:
14
Journal Article
Recenzirano
Odprti dostop
Using 116.1 fb − 1 of data collected by the BABAR detector, we present an analysis of Ξ 0 c production in B decays and from the c ¯ c continuum, with the Ξ 0 c decaying into Ω − K + and Ξ − π + ...final states. We measure the ratio of branching fractions B ( Ξ 0 c → Ω − K + ) / B ( Ξ 0 c → Ξ − π + ) to be 0.294 ± 0.018 ± 0.016 , where the first uncertainty is statistical and the second is systematic. The Ξ 0 c momentum spectrum is measured on and 40 MeV below the Υ ( 4 S ) resonance. From these spectra the branching fraction product B ( B → Ξ 0 c X ) × B ( Ξ 0 c → Ξ − π + ) is measured to be ( 2.11 ± 0.19 ± 0.25 ) × 10 − 4 , and the cross-section product σ ( e + e − → Ξ 0 c X ) × B ( Ξ 0 c → Ξ − π + ) from the continuum is measured to be ( 388 ± 39 ± 41 ) fb at a center-of-mass energy of 10.58 GeV.
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