E. Engels

EVIDENCE FOR PARTON KT EFFECTS IN HIGH-PT PARTICLE PRODUCTION

Inclusive pizero and direct-photon cross sections in the kinematic range 3.5 < pT < 12 GeV/c with central rapidities are presented for 530 and 800 GeV/c proton beams and a 515 GeV/c pi- beam incident on beryllium targets. Current Next-to-Leading-Order perturbative QCD calculations fail to adequately describe the data for conventional choices of scales. Kinematic distributions from these hard scattering events provide evidence that the interacting partons carry significant initial-state parton transverse momentum (kT). Incorporating these kT effects phenomenologically greatly improves the agreement between calculations and the measured cross sections.

Operation and Radiation Resistance of a FOXFET Biasing Structure for Silicon Strip Detectors

AC-coupled strip detectors biased with a FOXFET transistor structure have been studied. Measurement results for the basic operational characteristics of the FOXFET are presented together with a brief description of the physics underlying its operation. Radiation effects were studied using photons from a {sup 137}Cs source. Changes in the FOXFET characteristics as a function of radiation dose up to 1 MRad are reported. Results about the effect of radiation on the noise from a FOXFET biased detector are described. 13 refs.

Measurement of direct-photon production at the Fermilab Tevatron fixed target energies

Measurements of the production of high transverse momentum direct photons by a 515 GeV/c {pi}{sup -} beam and 530 and 800 GeV/c proton beams in interactions with beryllium and hydrogen targets are presented. The data span the kinematic ranges of 3.5<p{sub T}<12 GeV/c in transverse momentum and 1.5 units in rapidity. The inclusive direct-photon cross sections are compared with next-to-leading-order perturbative QCD calculations and expectations based on a phenomenological parton-k{sub T} model.

Direct photon production at high p-transverse in pi- Be and p Be collisions at 500-GeV/c

We report new measurements of inclusive direct photon production at high transverse momenta (pT) for π - and p interactions on Be at 500 Gev/r. The yields as a function of pT and rapidity (y) are in good agreement with expectations from next-to-leading-log QCD calculations employing recently extracted quark and gluon structure functions

Design and operation of large straw-tube drift chamber planes

Abstract We describe the design, construction and operation of a straw-tube drift chamber consisting of four X and four Y planes of 16 mm diameter straw

Production of 0 andmesons at large transverse momenta in pp and pBe interactions at 530 and 800 GeV/c

We present results on the production of high transverse momentum pizero and eta mesons in pp and pBe interactions at 530 and 800 GeV/c. The data span the kinematic ranges: 1 < p_T < 10 GeV/c in transverse momentum and 1.5 units in rapidity. The inclusive pizero cross sections are compared with next-to-leading order QCD calculations and to expectations based on a phenomenological parton-k_T model.

A large liquid argon photon/hadron calorimeter for FNAL

Abstract This paper describes a new liguid argon photon/hadron detector currently under construction for Experiment E706 at the Fermi National Accelerator Laboratory.

Calibration and performance of the E706 lead and liquid-argon electromagnetic calorimeter

Abstract We report on the calibration and performance of a large lead liquid-argon electromagnetic calorimeter used by experiment E706 at Fermilab. The reconstructed π 0 mass was used to calibrate the energy response of the calorimeter. The systematic uncertainty in the linearity and uniformity of the mean-energy response of the calorimeter after calibration was found to be less than ±0.5% for the sample of data analyzed. Detector characteristics, including sampling fluctuations and position resolution, are discussed.

Silicon position sensitive detectors for the Helios (NA 34) experiment

Abstract Silicon detectors having both “pad” and strip position sensitive configurations have been fabricated for the Helios experiment which requires an elaborate pulse height-dependent trigger as well as one dimensional silicon strip position sensing. The trigger detector is a 400 element, 30 mm diameter detector with readout connections from a ceramic overlay board. Tests with full prototype detectors have shown essentially 100% detection efficiency and excellent pulse height resolution well capable of delineating 0, 1 or 2 hits per pad. Strip detectors with 25 μm pitch and a varying readout pitch have been tested, which utilize both capacitive and resistive charge division. Techniques for realization of required interstrip resistors will be discussed and results which may compare these readout methods will be reported.

A silicon strip detector system for fermilab E706

Abstract Fermilab Experiment E706 is an experiment to study direct photon production in hadron-hadron collisions at the Fermilab Tevatron II. A part of the charged particle spectrometer is a silicon strip detector system used to determine the position of interaction vertices in the production target and to provide angular information about the secondary hadrons produced in a collision. We present some design criteria, as well as the results of tests of a water similar to those to be used in the experiment.