We report measurements of D production in interactions between 350 GeV=c particles and nuclei. Re... more We report measurements of D production in interactions between 350 GeV=c particles and nuclei. Reconstruction of the decay D + ! D 0 + and charge conjugate, with D 0 identied via its decays to K + and K + + , has allowed isolation of a sample of 611 28 D mesons, produced at positive x F . Assuming a linear A-dependence, the cross-section per nucleon in the region x F > 0 is measured to be 1:410:100:11 b for D + and 1:840:120:15 b for D . W e present measurements of dierential cross-sections with respect to x F and P t 2 , and compare data for D (vector-meson) production with data for production of charmed pseudoscalar mesons.
We report the first precision measurements of the scaled momentum, the charge multiplicity, and t... more We report the first precision measurements of the scaled momentum, the charge multiplicity, and the thrust of hadronic jets in the Breit frame in Deep Inelastic Scattering ν µ N andν µ N charged current events over the Q 2 range from 1 to 100 GeV 2 . The neutrino data, obtained in the NOMAD experiment at the CERN SPS, extend the Q 2 -evolution of these parameters by two orders of magnitude, and with commensurate precision, when compared to those reported by the ep and e + e − experiments.
A sample of 475 events, in which t w o c harmed-particle decays are observed, is analyzed to dete... more A sample of 475 events, in which t w o c harmed-particle decays are observed, is analyzed to determine distributions of two-particle kinematic variables. One charmed particle with x F > 0 is fully reconstructed and the other is at least partially recontructed. The distributions of and p 2 T are compared with a next-to-leading order QCD calculation.
We report on bipolar NPN phototransistors fabricated at ITC-IRST on thick high-resistivity silico... more We report on bipolar NPN phototransistors fabricated at ITC-IRST on thick high-resistivity silicon substrates. The phototransistor emitter is composed of a phosphorus n+ implant, the base is a diffused high-energy boron implant, and the collector is the 600-800 mm thick silicon bulk, contacted on the backplane. We have studied the current amplification for two different doping profiles of the emitter, obtaining values of b ranging from 60 to 3000. For various emitter and base configurations, we measured the static device characteristics and extracted the leakage currents and the base resistance, verifying the fundamental relationship between them and the total base capacitances. The use of such phototransistors to detect ionizing particles is exploited and discussed. r 2004 Published by Elsevier B.V.
The fragmentation of the hadronic system into Lambda, Sigma(1385), K) and K*(892) in deep-inelast... more The fragmentation of the hadronic system into Lambda, Sigma(1385), K) and K*(892) in deep-inelastic charged-current interactions of high energy neutrinos and antineutrinos with proton and neutron is analyzed. The results obtained for the production of these particles from the various initial states are compared with each other and with the predictions of the Lund fragmentation model. This comparison shows that a spectator diquark does not fragment as a whole in a fraction of the interactions. The role of the sea quarks in the baryon formation process is underlined. Strange vector and pseudoscalar mesons are likely to be produced at similar rates.
Using a sample of 10 8 triggered events, produced in 350 GeVrc p y interactions in a copper targe... more Using a sample of 10 8 triggered events, produced in 350 GeVrc p y interactions in a copper target, we have identified 26 bb events. These include 13 events where the decays of both B and B are well reconstructed. We measure the azimuthal correlation between beauty particles, and compare our result with predictions based on perturbative QCD. q 1998 Elsevier Science B.V. All rights reserved. 0370-2693r98r$ -see frontmatter q 1998 Elsevier Science B.V. All rights reserved.
... 1, it was decided to use only events with ph larger than 1.5 GeV/c. Further corrections have ... more ... 1, it was decided to use only events with ph larger than 1.5 GeV/c. Further corrections have to be applied for: 1.5 l1.0 z U b 11 o.~ 2.0 1.5 Z 1.o blb PHYSICS LETTERS Rvn ~ ~ Rv P 4 4 o +e ffft.ffff ee 00 e eeoe+ Rvn Rv-p + b + + O 1 2 O 1 pht -cut(GeV/c) 2 Fig. ...
Data from an exposure of the BEBC bubble chamber filled with deuterium to neutrino and antineutri... more Data from an exposure of the BEBC bubble chamber filled with deuterium to neutrino and antineutrino wide band beams have been used to extract the x dependence of the structure functions for scattering on protons and neutrons and the fractional momentum distributions ...
We h a v e searched for the decay D 0 ! + among 2:0 10 5 + pairs produced, in the WA92 experiment... more We h a v e searched for the decay D 0 ! + among 2:0 10 5 + pairs produced, in the WA92 experiment, by 350 GeV/c particles interacting in copper and tungsten targets. Using a high-resolution silicon-microstrip detector followed by a largeacceptance magnetic spectrometer and a muon lter we are able to measure the momentum of the muons, to visualize the event topology near their point of origin, and thus to discriminate between prompt and non-prompt muons. No D 0 ! + candidate has been found. This result allows us to set an upper limit on the branching fraction B(D 0 ! + ) of 4:1 10 6 at 90 % condence level.
Based on the full BABAR data sample, we report improved measurements of the ratios R (D (*))= B (... more Based on the full BABAR data sample, we report improved measurements of the ratios R (D (*))= B (B ̅→ D (*) τ-ν ̅ τ)/B (B ̅→ D (*) ℓ ℓ-ν ̅ ℓ), where ℓ is either e or μ. These ratios are sensitive to new physics contributions in the form of a charged Higgs boson. We measure R (D)= 0.440±0.058±0.042 and R (D*)= 0.332±0.024±0.018, which exceed the standard model expectations by 2.0 σ and 2.7 σ, respectively. Taken together, our results disagree with these expectations at the 3.4 σ level. This excess cannot be explained by a charged ...
We describe a measurement of the direct CP asymmetry between inclusive b → sγ and b → sγ decays. ... more We describe a measurement of the direct CP asymmetry between inclusive b → sγ and b → sγ decays. This asymmetry is expected to be less than 0.01 in the Standard Model, but could be
Using a data sample of 89 million Υ (4S) → BB decays collected with the BABAR detector at the PEP... more Using a data sample of 89 million Υ (4S) → BB decays collected with the BABAR detector at the PEP-II asymmetric B Factory at SLAC, we measure the B 0 (B 0 ) → ρ + ρ − branching fraction as (30±
We present partial branching fractions for inclusive charmless semileptonic B decays B → Xuℓν, an... more We present partial branching fractions for inclusive charmless semileptonic B decays B → Xuℓν, and the determination of the CKM matrix element |V ub |. The analysis is based on a sample of
We report measurements of D production in interactions between 350 GeV=c particles and nuclei. Re... more We report measurements of D production in interactions between 350 GeV=c particles and nuclei. Reconstruction of the decay D + ! D 0 + and charge conjugate, with D 0 identied via its decays to K + and K + + , has allowed isolation of a sample of 611 28 D mesons, produced at positive x F . Assuming a linear A-dependence, the cross-section per nucleon in the region x F > 0 is measured to be 1:410:100:11 b for D + and 1:840:120:15 b for D . W e present measurements of dierential cross-sections with respect to x F and P t 2 , and compare data for D (vector-meson) production with data for production of charmed pseudoscalar mesons.
We report the first precision measurements of the scaled momentum, the charge multiplicity, and t... more We report the first precision measurements of the scaled momentum, the charge multiplicity, and the thrust of hadronic jets in the Breit frame in Deep Inelastic Scattering ν µ N andν µ N charged current events over the Q 2 range from 1 to 100 GeV 2 . The neutrino data, obtained in the NOMAD experiment at the CERN SPS, extend the Q 2 -evolution of these parameters by two orders of magnitude, and with commensurate precision, when compared to those reported by the ep and e + e − experiments.
A sample of 475 events, in which t w o c harmed-particle decays are observed, is analyzed to dete... more A sample of 475 events, in which t w o c harmed-particle decays are observed, is analyzed to determine distributions of two-particle kinematic variables. One charmed particle with x F > 0 is fully reconstructed and the other is at least partially recontructed. The distributions of and p 2 T are compared with a next-to-leading order QCD calculation.
We report on bipolar NPN phototransistors fabricated at ITC-IRST on thick high-resistivity silico... more We report on bipolar NPN phototransistors fabricated at ITC-IRST on thick high-resistivity silicon substrates. The phototransistor emitter is composed of a phosphorus n+ implant, the base is a diffused high-energy boron implant, and the collector is the 600-800 mm thick silicon bulk, contacted on the backplane. We have studied the current amplification for two different doping profiles of the emitter, obtaining values of b ranging from 60 to 3000. For various emitter and base configurations, we measured the static device characteristics and extracted the leakage currents and the base resistance, verifying the fundamental relationship between them and the total base capacitances. The use of such phototransistors to detect ionizing particles is exploited and discussed. r 2004 Published by Elsevier B.V.
The fragmentation of the hadronic system into Lambda, Sigma(1385), K) and K*(892) in deep-inelast... more The fragmentation of the hadronic system into Lambda, Sigma(1385), K) and K*(892) in deep-inelastic charged-current interactions of high energy neutrinos and antineutrinos with proton and neutron is analyzed. The results obtained for the production of these particles from the various initial states are compared with each other and with the predictions of the Lund fragmentation model. This comparison shows that a spectator diquark does not fragment as a whole in a fraction of the interactions. The role of the sea quarks in the baryon formation process is underlined. Strange vector and pseudoscalar mesons are likely to be produced at similar rates.
Using a sample of 10 8 triggered events, produced in 350 GeVrc p y interactions in a copper targe... more Using a sample of 10 8 triggered events, produced in 350 GeVrc p y interactions in a copper target, we have identified 26 bb events. These include 13 events where the decays of both B and B are well reconstructed. We measure the azimuthal correlation between beauty particles, and compare our result with predictions based on perturbative QCD. q 1998 Elsevier Science B.V. All rights reserved. 0370-2693r98r$ -see frontmatter q 1998 Elsevier Science B.V. All rights reserved.
... 1, it was decided to use only events with ph larger than 1.5 GeV/c. Further corrections have ... more ... 1, it was decided to use only events with ph larger than 1.5 GeV/c. Further corrections have to be applied for: 1.5 l1.0 z U b 11 o.~ 2.0 1.5 Z 1.o blb PHYSICS LETTERS Rvn ~ ~ Rv P 4 4 o +e ffft.ffff ee 00 e eeoe+ Rvn Rv-p + b + + O 1 2 O 1 pht -cut(GeV/c) 2 Fig. ...
Data from an exposure of the BEBC bubble chamber filled with deuterium to neutrino and antineutri... more Data from an exposure of the BEBC bubble chamber filled with deuterium to neutrino and antineutrino wide band beams have been used to extract the x dependence of the structure functions for scattering on protons and neutrons and the fractional momentum distributions ...
We h a v e searched for the decay D 0 ! + among 2:0 10 5 + pairs produced, in the WA92 experiment... more We h a v e searched for the decay D 0 ! + among 2:0 10 5 + pairs produced, in the WA92 experiment, by 350 GeV/c particles interacting in copper and tungsten targets. Using a high-resolution silicon-microstrip detector followed by a largeacceptance magnetic spectrometer and a muon lter we are able to measure the momentum of the muons, to visualize the event topology near their point of origin, and thus to discriminate between prompt and non-prompt muons. No D 0 ! + candidate has been found. This result allows us to set an upper limit on the branching fraction B(D 0 ! + ) of 4:1 10 6 at 90 % condence level.
Based on the full BABAR data sample, we report improved measurements of the ratios R (D (*))= B (... more Based on the full BABAR data sample, we report improved measurements of the ratios R (D (*))= B (B ̅→ D (*) τ-ν ̅ τ)/B (B ̅→ D (*) ℓ ℓ-ν ̅ ℓ), where ℓ is either e or μ. These ratios are sensitive to new physics contributions in the form of a charged Higgs boson. We measure R (D)= 0.440±0.058±0.042 and R (D*)= 0.332±0.024±0.018, which exceed the standard model expectations by 2.0 σ and 2.7 σ, respectively. Taken together, our results disagree with these expectations at the 3.4 σ level. This excess cannot be explained by a charged ...
We describe a measurement of the direct CP asymmetry between inclusive b → sγ and b → sγ decays. ... more We describe a measurement of the direct CP asymmetry between inclusive b → sγ and b → sγ decays. This asymmetry is expected to be less than 0.01 in the Standard Model, but could be
Using a data sample of 89 million Υ (4S) → BB decays collected with the BABAR detector at the PEP... more Using a data sample of 89 million Υ (4S) → BB decays collected with the BABAR detector at the PEP-II asymmetric B Factory at SLAC, we measure the B 0 (B 0 ) → ρ + ρ − branching fraction as (30±
We present partial branching fractions for inclusive charmless semileptonic B decays B → Xuℓν, an... more We present partial branching fractions for inclusive charmless semileptonic B decays B → Xuℓν, and the determination of the CKM matrix element |V ub |. The analysis is based on a sample of
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