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Preliminary measurement of the inclusive jet and dijet cross section in {bar p}p collisions at {radical} s = 1.8 TeV

Description: We report on preliminary measurements of the central, |{eta}| {le} 0.5, inclusive jet and dijet cross sections at {radical}s = 1.8 TeV. Two data sets with integrated luminosities of 91 pb{sup {minus}1} and 14 pb{sup {minus}1} were collected at the Fermilab Tevatron p{ovr p} Collider with the D0 detector. The inclusive jet cross section measured with both data sets and reported as a function of transverse jet energy (35 GeV {le} E{sub T} {le} 470 GeV) and the dijet cross section measured with the 91 pb{sup {minus}1} data set and reported as a function of dijet mass (200 GeV {le} M{sub JJ} {le} 1 TeV) are in excellent agreement with next-to-leading order QCD. 11 refs., 5 figs.
Date: June 1, 1996
Creator: Blazey, G.C.
Partner: UNT Libraries Government Documents Department

QCD at D0 and CDF

Description: Selected recent Quantum Chromodynamics (QCD) results from the D0 and CDF experiments at the Fermilab Tevatron are presented and discussed. The inclusive jet and inclusive triple differential dijet cross sections are compared to next-to-leading order QCD calculations. The sensitivity of the dijet cross section to parton distribution functions (for hadron momentum fractions {approximately} 0.01 to {approximately} 0.4) will constrain the gluon distribution of the proton. Two analyses of dijet production at large rapidity separation are presented. The first analysis tests the contributions of higher order processes to dijet production and can be considered a test of BFKL or GLAP parton evolution. The second analysis yields a strong rapidity gap signal consistent with colorless exchange between the scattered partons. The prompt photon inclusive cross section is consistent with next-to-leading order QCD only at the highest transverse momenta. The discrepancy at lower momenta may be indicative of higher order processes impacting a transverse momentum or ``k{sub T}`` to the partonic interaction. The first measurement of the strong coupling constant from the Tevatron is also presented. The coupling constant can be determined from the ratio of W + 1jet to W + 0jet cross sections and a next-to-leading order QCD calculation.
Date: May 1, 1995
Creator: Blazey, G.C.
Partner: UNT Libraries Government Documents Department

Effects of the 9-T magnetic field on MRS photodiode

Description: The experimental results on the performance of the MRS (Metal/Resistor/Semiconductor) photodiode in the strong magnetic field of 9T, and the possible impact of the quench of the magnet at 9.5T on sensor's operation are reported. The measurement method used is being described. The results of the work agree with the expectations that the MRS photodiode is not exhibiting sensitivity to the magnetic field presence. This result is essential for the design of the future electron-positron linear collider detector.
Date: October 1, 2005
Creator: Beznosko, D.; Blazey, G.; Dyshkant, A.; Rykalin, V. & U., /Northern Illinois
Partner: UNT Libraries Government Documents Department

Modular design of long narrow scintillating cells for ILC detector

Description: The experimental results for the narrow scintillating elements with effective area about 20 cm{sup 2} are reported. The elements were formed from the single piece of scintillator and were read out via wavelength shifting fibers with the MRS (Metal/Resistor/Semiconductor) photodiodes on both ends of each fiber. The formation of the cells from the piece of scintillator by using grooves is discussed. The cell performance was tested using the radioactive source by measuring the PMT current and a single rate after amplifier and discrimination with threshold at about three photo electrons in each channel and quad coincidences (double coincidences between sensors on each fiber and double coincidences between two neighboring fibers). This result is of high importance for large multi-channel systems, i.e. module may be used as an active element for calorimeter or muon system for the design of the future electron-positron linear collider detector because cell effective area can be smoothly enlarged or reduced (to 4 cm{sup 2} definitely).
Date: September 1, 2005
Creator: Beznosko, D.; Blazey, G.; Dyshkant, A.; Maloney, J.; Rykalin, V.; U., /Northern Illinois et al.
Partner: UNT Libraries Government Documents Department

Two jet energy and rapidity distributions

Description: The D0 detector has been recording data at the Tevatron [bar p]p Collider since May 1992. Because the D0 calorimeter is hermetic and has large acceptance it is well suited for semi-exclusive final state jet studies. We present a primary measurement of the distribution d[sup 3]N/dE[sub t1]/d[eta][sub 1]/d[eta][sub 2] at [radical]s TeV over a large range of [eta]. The sensitivity of this cross-section to parton momentum distributions and the ability of D0 to discriminate between possible parton distributions is discussed.
Date: November 1, 1992
Creator: Blazey, G.C.
Partner: UNT Libraries Government Documents Department

Two jet energy and rapidity distributions

Description: The D0 detector has been recording data at the Tevatron {bar p}p Collider since May 1992. Because the D0 calorimeter is hermetic and has large acceptance it is well suited for semi-exclusive final state jet studies. We present a primary measurement of the distribution d{sup 3}N/dE{sub t1}/d{eta}{sub 1}/d{eta}{sub 2} at {radical}s TeV over a large range of {eta}. The sensitivity of this cross-section to parton momentum distributions and the ability of D0 to discriminate between possible parton distributions is discussed.
Date: November 1, 1992
Creator: Blazey, G. C. & Collaboration, For the D {O}
Partner: UNT Libraries Government Documents Department

MAPMT H7546B anode current response study for ILC SiD muon system prototype

Description: The proposed Silicon Detector (SiD) concept for the ILC has barrel and end cap muon systems. An SiD scintillator based muon system prototype has 256 strips and was constructed from extruded strips, WLS fibers, clear fibers, and multianode photo multiplier tubes (MAPMT) Hamamatsu H7546B. Six MAPMTs were used. As a first step to understand strip output, the response of every anode to a given brightness of light and applied voltage must be measured. For the test, a custom made light source was used. Each MAPMT output was measured independently. The anode currents were measured at constant (green) input light brightness and the same photocathode to anode voltage (800V). The anode currents have a wide spread; for all tubes the maximum value is 5.23 times larger than the minimum value. The MAPMT cross talk was measured for one of the central inputs. The maximum cross talk value is about 4.9%. The average cross talk for the nearest four neighboring channels is 3.9%, for the farthest four is 1%. To assure the reproducibility and repeatability of the measurements, the double reference method was used.
Date: October 1, 2007
Creator: Dyshkant, A.; Blazey, G.; Francis, K.; Hedin, D.; Zutshi, V.; U., /Northern Illinois et al.
Partner: UNT Libraries Government Documents Department

Quality control studies of wavelength shifting fibers for a scintillator-based tail-catcher muon-tracker linear collider prototype detector

Description: Detailed measurements of the wavelength shifting fiber response to a stable and reliable light source are presented. Details about materials, a double reference method, and measurement technique are included. The fibers studied were several hundred KURARAY, Y-11, multiclad, 1.2mm outer diameter wavelength shifting fibers each cut from a reel to about one meter length. The fibers were polished, mirrored, and the mirrors were UV epoxy protected. Each fiber passed quality control requirements before installation. About 94% of the fibers have a response within 1% of the overall mean.
Date: May 1, 2006
Creator: Dyshkant, A.; Beznosko, D.; Blazey, G.; Rykalin, V.; Zutshi, V.; U., /Northern Illinois et al.
Partner: UNT Libraries Government Documents Department

Hard quark-quark scattering with exclusive reactions

Description: We present data from ..pi../sup -/p ..-->.. elastic and rho/sup -/p final states for scattering at 90/sup 0/ center of mass, -t = 9 GeV/sup 2//c/sup 2/. A large rho/sup -/p signal is seen and the rho/sup -/ is strongly polarized. This polarization tests a QCD prediction that quarks cannot flip helicity. The test fails dramatically. 9 references, 4 figures.
Date: January 1, 1984
Creator: Barton, D.S.; Bunce, G.M.; Carroll, A.S.; Makdisi, Y.I.; Baller, B.; Blazey, G.C. et al.
Partner: UNT Libraries Government Documents Department

Exclusive reactions and dimensional scaling: New measurements and new understanding

Description: This experiment has measured 11 meson-baryon and 2 baryon-baryon cross sections at 90/sup 0/. When interpreted in terms of underlying hard quark-quark scattering diagrams, the process of quark interchange between the incident hadrons clearly dominates over other graphs such as pure gluon exchange amd quark annihilation/creation. While there is no theoretical prediction for this dominance yet, there is an indication of underlying simplicity. In a continuing program at the Brookhaven AGS we have initial indication of a strikingly large cross section for proton-proton elastic scattering inside nuclei at 90/sup 0/ and incident momentum of 10 GeV/c (-t = (9 GeV/c)/sup 2/). This result suggests that those protons which scatter elastically to large angles have a smaller cross section for additional interactions (less shadowing) while traversing a nucleus than those undergoing normal small momentum transfer collisions, an effect predicted by the above interpretation. 11 refs., 8 figs.
Date: January 1, 1987
Creator: Carroll, A.S.; Barton, D.S.; Bunce, G.; Gushue, S.; Makdisi, Y.I.; Baller, B. et al.
Partner: UNT Libraries Government Documents Department

Hard quark-quark scattering with exclusive reactions

Description: We have begun a program designed to study hard quark-quark scattering with exclusive reactions, focusing on quasi-elastic two-body reactions with all possible quark flavor exchanges. Examples are ..pi../sup -/p ..-->.. ..pi../sup -/p, rho/sup -/p, ..pi../sup +/..delta../sup -/, K/sup +/..sigma../sup -/, or K..lambda... Of the two-body exclusives, only elastic scattering had been measured at such large t previous to our experiment. By comparing the relative importance of different final states, the energy dependence of the production ratios of these states, the prominence of resonances such as rho/sup -/ over background in this region, and measuring polarizations where accessible, we have collected a large body of data on hard scattering in a completely new domain. Previously, essential all short distance QCD tests have been for inclusive processes. We have taken data with both negative and positive incident beam at 10 GeV/c on a hydrogen target and will present the first results, for ..pi../sup -/p ..-->.. ..pi../sup -/p and rho/sup -/p at THETA/sub cm/ = 90/sup 0/, -t = 9 GeV/sup 2//c/sup 2/. The apparatus consists of a magnetic spectrometer, with Cerenkov particle identification, which selects stable charged particles (protons in this case) at high momentum near 90/sup 0/ in the center-of-mass. A large aperture array of PWCs observes the recoil particle or charged decay products. Cross sections are extremely low, approximately a 1 nb/(GeV/c)/sup 2/ for elastic scattering. We will report on a sample of more than 1000 ..pi../sup -/p elastic events, and on rho/sup -/p, where the rho/sup -/ decay distribution was observed. We find a surprisingly large rho/sup -/p cross section in this large momentum transfer region, with rho/sup -/p about half the elastic cross section, and a striking spin alignment of the rho/sup -/.
Date: July 19, 1984
Creator: Barton, D.S.; Bunce, G.M.; Carroll, A.S.; Makdisi, Y.I.; Baller, B.; Blazey, G.C. et al.
Partner: UNT Libraries Government Documents Department

Study of quark flavor-dependence in exclusive reactions at large momentum transfers

Description: The measurement of exclusive reactions at large momentum transfers provides an important testing ground for models of hard quark-quark scattering. We have measured cross sections or set upper limits for 12 meson-bryon (..pi../sup +-/p ..-->.. p..pi../sup +-/, p/rho//sup +-/, ..pi../sup +/..delta../sup +-/, K/sup +/..sigma../sup +-/, ..pi../sup /minus//p ..-->.. ..lambda../sup 0//..sigma../sup 0/K/sup 0/, K/sup +-/p ..-->.. pK/sup +-/) and 2 baryon-baryon (p/sup +-/p ..-->.. pp/sup /plus minus/) reactions near 90/degree/ C.M. by studying the flavor-dependence of these 2 exclusive reactions at t = -9(GeV/c)/sup 2/, we have been able to demonstrate in a perturbative QCD picture that the quark-interchange mechanism is dominant over gluon exchange and quark-antiquark annihilation. We will also present preliminary results on many of these reactions at t = -5(GeV/c)/sup 2/ with better resolution and statistical precision. 145 refs., 3 figs.
Date: January 1, 1988
Creator: Carroll, A.S.; Appel, R.; Barton, D.S.; Bunce, G.; Kmit, M.; Makdisi, Y.I. et al.
Partner: UNT Libraries Government Documents Department

LC scintillator-based muon detector tail-catcher R&D

Description: Preliminary analysis of test beam data from strip scintillator planes read-out with multi-anode PMTs (MAPMTs) is presented along with a description of the independent systematic measurements of relative response for all channels of several MAPMTs used in the tests. Test beam measurements for the response of a scintillator strip, read out with Si photo-sensors, is also described.
Date: November 1, 2007
Creator: Abrams, R.; Blazey, G.; Driutti, A.; Dychkant, A.; Fisk, H.E.; Gutierrez, A. et al.
Partner: UNT Libraries Government Documents Department