123088836
Search for short-lived particles in high-energy neutrino interactions identified using a hybrid emulsion-spark-chamber arrangement
Seventeen litres of nuclear photographic emulsion have been exposed to the wide-band neutrino beam at Fermilab. Tracks of secondaries from neutrino interactions in the emulsion were observed in a wide-gap spark chamber and a system of narrow-gap spark chambers and counters down beam. From measurements on the tracks in the wide-gap chamber the positions of vertices from which the secondaries diverged were predicted and 37 neutrino interactions in emulsion were located. Factors affecting the efficiency of location of events searched for (approx.20% in this experiment) are assessed and conclusions drawn about means of optimizing the design of experiments employing emulsion hybrid techniques. In one of the interactions a secondary track gave rise to three tracks after a distance of 182 ..mu..m. Further measurements made on this event do not alter the previous conclusion of its most likely interpretation as the decay of a short-lived particle of lifetime approx.6 x 10/sup -13/ sec.
121757543
Measurement of single spin asymmetry for direct photon production in pp collisions at 200 GeV/c
The single spin asymmetry for inclusive direct-photon production has been measured using a polarized proton beam of 200 GeV/c with an unpolarized proton target at −0.15 < xf < 0.15 and 2.5 < pt < 3.1 GeV/c at Fermilab. The data on the cross section for pp → γX at 2.5 < pt < 3.8 GeV/c are also provided. The measurement was done using lead-glass calorimeters and photon detectors which surrounded the fiducial area of the calorimeters. Background rejection has been done using these surrounding photon detectors. The cross section obtained is consistent with the results of previous measurements assuming a nuclear dependence of A1.0. The single spin asymmetry, AN, for the direct-photon production is consistent with zero within experimental uncertainty.
118121131
USE OF THE 3.5-MRAD BEAM FOR ELECTRONS.
123662576
Observation of a likely example of the decay of a charmed particle produced in a high energy neutrino interaction
Abstract In a study of neutrino interactions occurring in nuclear emulsion, an event has been found that is most readily interpreted as the decay of a charmed particle with lifetime a few times 10 −13 s.
120981188
LARGE-ANGLE PION--PROTON ELASTIC SCATTERING AT HIGH ENERGIES.
124689502
A POSSIBLE SPECTROMETER FOR ACCOMPLISHING A SECONDARY BEAM SURVEY AT NAL.
120705876
Presentation of search results: the CLs technique
I describe a framework for the presentation of search results which is motivated by frequentist statistics. The most well-known use of this framework is for the combined search for the Higgs boson at LEP. A toy neutrino oscillations experiment is used to illustrate the rich information available in the framework for exclusion and discovery. I argue that the so-called CLs technique for setting limits is appropriate for determining exclusion intervals while the determination of confidence intervals advocated by Feldman and Cousins' method is more appropriate for treating established signals, i.e. going beyond discovery to measurement. (From the workshop 'Advanced Statistical Techniques in Particle Physics', 18–22 March 2002)
108830204
A CMOS charge sensitive amplifier for silicon strip detectors: Design criteria and test results
Abstract A low noise charge sensitive amplifier has been developed with a commercial CMOS process. We present measurements of the amplifier's performance when used to read out a silicon strip detector exposed to a particle beam. A few prototypes have been exposed to large doses of radiation in order to study the radiation hardness.
117135799
Physics with the MAC detector
New results, obtained during the previous year at the PEP colliding beam rings with the MAC detector at a center of mass energy of 29 GeV, are presented.
123179979
The discovery and measurements of a Higgs boson
The discovery of a Higgs-like boson with a mass of approximately 125?GeV by the ATLAS and CMS experiments at the Large Hadron Collider was announced at CERN on 4 July 2012. The data-set of 5?fb?1 of proton?proton collisions with collected during 2011 and 6?fb?1 with collected in 2012 up to the July discovery was supplemented by an additional 15?fb?1 of data with collected during the rest of 2012. The measurements of the properties of the new boson with the combined data-set have substantially strengthened the evidence that this new particle is indeed the Higgs boson predicted to exist as a consequence of the Brout?Englert?Higgs-mechanism that takes responsibility for generating masses of fundamental particles and for the electroweak symmetry breaking.
111306611
Prototype design, construction and test of a Pb/scintillator sampling calorimeter with wavelength shifter fiber optic readout
A prototype for the new DELPHI luminosity monitor has been built and tested. The scope of this prototype is to measure the response of the proposed calorimeter in the region which is most critical for the luminosity measurement, i.e., at the inner edge of the acceptance. The aim of the new luminosity monitor is to measure the LEP (Large Electron Position Collider) luminosity with per mill systematic uncertainty. This requires experimental biases at the level of 50 mu m or less in the definition of the fiducial volume. The technique used ensures good energy resolution and high spatial uniformity. With the prototype, better than 2% uniformity in response and an energy resolution of 3% at 45 GeV have been achieved. >