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18 results on '"Walker, W. D."'

1. Simple Behavior of Primary Cross Sections for Low Mass Particles in p-pbar Collisions at y=0 and sqrt(s)=1.8 TeV

Author

Alexopoulos, T., Anderson, E. W., Carmony, D. D., Erwin, A. R., Findeisen, C., Gulbrandsen, K., Gutay, L. J., Hirsch, A. S., Hojvat, C., Jennings, J. R., Loomis, C., LoSecco, J. M, Nelson, K. S., Oh, S. H., Porile, N. T., Scharenberg, R. P., Turkot, F., Walker, W. D., Wang, C. H., and Warchol, J.

Subjects
High Energy Physics - Experiment
Abstract

A set of inclusive cross sections at zero rapidity is presented for p-pbar interactions at center of mass energy sqrt(s)=1.8 TeV. Six particle cross sections are corrected for secondary contributions from decays of higher mass resonances in order to produce a set of primary cross sections. The primary cross sections per spin state are well described by d(sigma^p)/dy|_(y=0)= 0.721*(pi*lambdabar_(pi)^2)*exp(-m/T), where m is the particle rest mass, T=hbar*c/r_h, and r_h=0.97 fm. The deuterium production cross section is also described if r_h is replaced by r_A=r_h*A^(1/3). The same exponential in m and T describes primary charm fractions in e+e- collisions at least up to the J/Psi mass. There is no significant evidence for strangeness or charm suppression if only primary production of light hadrons is considered. There is evidence that the primary cross section for each particle may have the same value for pp and pbar-p collisions and that it may have nearly constant values between sqrt(s)=63 GeV and sqrt(s)=1800 GeV. Fits to the final state transverse momenta of the particles using a gas model favor a temperature T=132 MeV, a chemical potential mu=129 MeV, and a transverse flow of the gas with beta_f=0.27., Comment: 20 pages, 18 figures

Published
2009

2. Evidence for hadronic deconfinement in $\bar{p}$-p collisions at 1.8 TeV

Author

Alexopoulos, T., Anderson, E. W., Bujak, A. T., Carmony, D. D., Erwin, A. R., Gutay, L. J., Hirsch, A. S., Nelson, K. S., Porile, N. T., Oh, S. H., Scharenberg, R. P., Srivastava, B. K., Stringfellow, B. C., Turkot, F., Warchol, J., and Walker, W. D.

Subjects
High Energy Physics - Experiment
Abstract

We have measured deconfined hadronic volumes, $4.4 < V < 13.0$ fm$^{3}$, produced by a one dimensional (1D) expansion. These volumes are directly proportional to the charged particle pseudorapidity densities $6.75 < dN_{c}/d\eta < 20.2$. The hadronization temperature is $T = 179.5 \pm 5$ (syst) MeV. Using Bjorken's 1D model,the hadronization energy density is $\epsilon_{F} = 1.10 \pm 0.26$ (stat) GeV/fm$^{3}$ corresponding to an excitation of $24.8 \pm 6.2$ (stat) quark-gluon degrees of freedom., Comment: 15 pages, 3 figures, 2 tables

Published
2002
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3. A Search for Disoriented Chiral Condensate at the Fermilab Tevatron

Author

MiniMax Collaboration, Brooks, T. C., Convery, M. E., Davis, W. L., Del Signore, K. W., Jenkins, T. L., Kangas, E., Knepley, M. G., Kowalski, K. L., Taylor, C. C., Oh, S. H., Walker, W. D., Colestock, P. L., Hanna, B., Martens, M., Streets, J., Ball, R. C., Gustafson, H. R., Jones, L. W., Longo, M. J., Bjorken, J. D., Abashian, A., Morgan, N., and Pruneau, C. A.

Subjects
High Energy Physics - Experiment
Abstract

We present results from MiniMax (Fermilab T-864), a small test/experiment at the Tevatron designed to search for the production of disoriented chiral condensate (DCC) in $p - \bar p$ collisions at $\sqrt{s} = 1.8$ TeV in the forward direction, $\sim 3.4 < \eta < \sim 4.2$. Data, consisting of $1.3 \times 10^6$ events, are analyzed using the robust observables developed in an earlier paper. The results are consistent with generic, binomial-distribution partition of pions into charged and neutral species. Limits on DCC production in various models are presented., Comment: 24 pages, 9 figures. Minor clarifications have been added

Published
1999
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4. Multiplicity Distribution and Mechanisms of the High-Energy Hadron Collisions

Author

Matinyan, S. G. and Walker, W. D.

Subjects
High Energy Physics - Phenomenology
Abstract

We discuss the multiplicity distribution for highest accessible energies of $pp$- and $\bar pp$- interactions from the point of view of the multiparton collisions. The inelastic cross sections for the single, $\sigma_1$, and multiple (double and, presumably, triple, $\sigma_{2+3}$) parton collisions are extracted from the analysis of the experimental data on the multiplicity distribution up to the Tevatron energies. It follows that $\sigma_1$ becomes energy independent while $\sigma_{2+3}$ increases with $\sqrt{s}$ for $\sqrt{s}\ge$ 200 GeV. The observed growth of $$ with multiplicity is attributed to the increasing role of multiparton collisions for the high energy $\bar pp(pp)$- inelastic interactions., Comment: Revtex file, 17 pages, 5 figures

Published
1998
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5. Preliminary Results from a Search for Disoriented Chiral Condensates at MiniMax

Author

Brooks, T. C., Convery, M. E., Davis, W. L., Delsignore, K. W., Jenkins, T. L., Kangas, E., Knepley, M. G., Kowalski, K. L., Taylor, C. C., Oh, S. H., Walker, W. D., Colestock, P. L., Hanna, B., Martens, M., Streets, J., Ball, R., Gustafson, H. R., Jones, L. W., Longo, M. J., Bjorken, J. D., Abashian, A., Morgan, N., and Pruneau, C. A.

Subjects
High Energy Physics - Experiment
Abstract

We report on the progress of a search for disoriented chiral condensates (DCCs) in the far forward region at sqrt(s)=1.8 TeV. MiniMax is a small collider experiment situated at the C0 interaction region of the Tevatron and has been designed to measure the ratio of charged to neutral pions produced at eta near 4.1. The distribution of this ratio is expected to be very different for the generic binomial and DCC particle production models. We present a method used for the search using the factorial moments of particle generating functions, which can be extracted directly from the data. A preliminary comparison of robust ratios of measured values and those expected from the different models is also presented., Comment: Latex, 2 figures, 3 pages, To appear in the proceedings of DPF 96.

Published
1996

6. The Limiting Curve of Leading Particles from Hadron-Nucleus Collisions at Infinite A

Author

Berera, A., Strikman, M., Toothacker, W. S., Walker, W. D., and Whitmore, J. J.

Subjects
High Energy Physics - Phenomenology
Abstract

We argue that as the atomic number of the target nucleus $A \to \infty$, the multiplicity of leading particles in hadron-nucleus collisions tends to a finite limit. The limiting multiplicities for various particle production are computed for both proton and pion projectiles. Signatures at finite A are discussed. Data from 100 GeV/c central hadron-nucleus collisions are analyzed and found to be in qualitative agreement with this picture., Comment: 14 pages, 2 figures, 1 table, In press Physics Letters B 1997

Published
1996
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7. Search for disoriented chiral condensate at the Fermilab Tevatron

Author

MiniMax Collaboration, Brooks, T. C., Convery, M. E., Davis, W. L., Del Signore, K. W., Jenkins, T. L., Kangas, E., Knepley, M. G., Kowalski, K. L., Taylor, C. C., Oh, S. H., Walker, W. D., Colestock, P. L., Hanna, B., Martens, M., Streets, J., Ball, R. C., Gustafson, H. R., Jones, L. W., Longo, M. J., Bjorken, J. D., Abashian, A., Morgan, N., and Pruneau, C. A.

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Meson, Nuclear Theory, High Energy Physics::Phenomenology, Hadron, Tevatron, FOS: Physical sciences, Elementary particle, Approx, High Energy Physics - Experiment, Nuclear physics, High Energy Physics - Experiment (hep-ex), Pion, High Energy Physics::Experiment, Fermilab, Nuclear Experiment, QC, Boson
Abstract

We present results from MiniMax (Fermilab T-864), a small test/experiment at the Tevatron designed to search for the production of disoriented chiral condensate (DCC) in $p - \bar p$ collisions at $\sqrt{s} = 1.8$ TeV in the forward direction, $\sim 3.4 < ��< \sim 4.2$. Data, consisting of $1.3 \times 10^6$ events, are analyzed using the robust observables developed in an earlier paper. The results are consistent with generic, binomial-distribution partition of pions into charged and neutral species. Limits on DCC production in various models are presented., 24 pages, 9 figures. Minor clarifications have been added

Published
2000
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9. Attitudinal Survey of Producers Involved in a Meat Goat Artificial Insemination Clinic.

Author

Walker, E. L., Vaught, C. R., Walker, W. D., and Nusz, S. R.

Subjects
GOAT meat, ARTIFICIAL insemination of goats, ATTITUDE (Psychology), MOTIVATION (Psychology), LIVESTOCK
Abstract

To quantify intrinsic learning processes, the Intrinsic Motivation Inventory (IMI) was established and incorporated into a questionnaire provided to participants in two meat goat artificial insemination clinics. Pre-test and post-test results on meat goat knowledge, motivation constraints, and confidence in livestock management skills were compared to assess the impact of the instructional clinics. In both months, participants increased their examination scores and improved confidence in their livestock management skills. Understanding of key aspects of the IMI may be of importance when planning educational programs for agricultural producers coming from a variety of different backgrounds and experiences. [ABSTRACT FROM AUTHOR]

Published
2011
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12. Charm photoproduction at 20 GeV

Author

Abe, K, Bacon, Trevor C, Ballam, J, Bevan, A V, Bingham, Harry H, Brau, J E, Braune, K, Brick, D H, Bugg, W M, Butler, J M, Cameron, W, Carroll, J T, Chima, J S, Cohn, H O, Colley, D C, Condo, G T, Dado, S, Diamond, R, Dornan, Peter J, Erickson, R, Field, R C, Franek, B J, Fujiwara, N, Furuno, K, Gearhart, R A, Gershoni, D, Glanzman, T, Godfrey, I M, Goldberg, J, Gopol, G P, Goshaw, A T, Hagopian, V, Hall, G, Hancock, E R, Handler, T, Hargis, H J, Hart, E L, Harwin, M J, Hasegawa, K, Hayashino, T, Hideta, I, Hulsizer, R I, Isacson, S, Jobes, M, Kalmus, George Ernest, Kelsey, D P, Kent, J, Kitagaki, T, Lannutti, J E, Levy, A, Lucas, P W, Mann, W A, Merenyi, R, Milburn, R H, Milstene, C, Moffeit, K C, Murray, J J, Napier, A, Noguchi, S, Ochiai, F, Ohtani, Y, O'Neale, S W, Palounek, A P T, Pless, I A, Rankin, P, Robertson, W J, Rogers, A H, Ronat, E, Rudnicka, H, Sagawa, H, Sato, T, Schneps, J, Sewell, S J, Shank, J T, Shapiro, A M, Sugahara, R, Suzuki, A, Takahashi, K, Tamai, K, Tanaka, S, Tether, S, Waide, D A, Walker, W D, Widgoff, M, Wilkins, C G, Wolbers, S, Woods, C A, Yamaguchi, A, Yamamoto, R K, Yamashita, S, Yekutieli, G, Yoshimura, Y, Yost, G P, and Yuta, H

Subjects
Particle Physics - Experiment
Published
1984

13. Lifetime measurement of $\Lambda_{c}$

Author

Aguilar-Benitez, M., Allison, W W M., Bailly, J L., Bartl, W., Selldn, B., Begalli, M., Beillire, P., Bizzarri, R., Briand, H., Brun, R., Canale, V., Caso, C., Castelli, E., Checchia, P., Chliapnikov, P V., Colino, N., Colwill, S J., Contri, R., Crennell, D., Cresti, M., De Angelis, A., De Billy, L., Defoix, C., Di Marco, R., Di Capua, E., Diez Hedo, F J., Dolbeau, J., Duboc, J., Dumarchez, J., Eriksson, M., Falciano, S., Fernndez, C., Fisher, C., Fisyak Yu, V., Fontanelli, F., Fry, J R., Gasparini, U., Gensch, U., Gentile, S., Gibaut, D B., Goshaw, A T., Gurtu, A., Hamatsu, R., Haupt, L., Hellman, S., Henri, V., Hernandez, J J., Holmgren, S O., Houlden, M., Hrubec, J., Hughes, P., Huss, D., Iga, Y., Iori, M., Jegham, E., Johansson, E K., Josa-Mutuberria, I., Kalelkar, M., Kholodenko, A G., Kistenev, E P., Kitamura, S., Knauss, D., Kniazev, V V., Kowald, W., Kuhn, D., Laberrigue, J., Laloum, M., Legros, P., Leutz, H., MacDermott, M., Mason, P., Mazzucato, M., Michalon-Mentzer, M.E., Michalon, A., Moa, T., Monge, R., Montanet, L., Naumann, T., Neuhofer, G., Nguyen, H K., Nilsson, S., Nowak, H., Oshima, N., Otter, G., Ouared, R., Panella Comellas, J., Patel, G., Pernicka, M., Pilette, P., Pinori, C., Piredda, G., Plano, R., Poppleton, A., Poropat, P., Raghavan, R., Reucroft, S., Roberts, K., Robertson, W J., Rohringer, H., Salicio, J M., Schulte, R., Sessa, M., Squarcia, S., Stamer, P E., Stopchenko, V A., Subramanian, A., Sudhakar, K., Takahashi, K., Touboul, M C., Trevisan, U., Troncon, C., Tsurugai, T., Ventura, Laurent, Vilain, P., Vlasov, E V., Voltolini, C., Vonck, C., Walker, W D., Wild, C F., Yiou, T P., Zumerle, G., Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches Subatomiques (IReS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Cancéropôle du Grand Est-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), and LEBC-EHS

Subjects
[PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Particle Physics - Experiment
Published
1987

14. D-meson production from 400 GeV/c p-p interactions evidence for leading di-quarks

Author

Aguilar-Benítez, M, Allison, W W M, Bailly, J L, Banerjee, S, Selldén, B, Bartl, Walter, Begalli, M, Beillière, P, Bizzarri, R, Briand, H, Canale, V, Caso, Carlo, Castelli, Edoardo, Checchia, P, Chliapnikov, P V, Colino, N, Colwill, S J, Contri, R, Crennell, D J, De Angelis, A, De Billy, L, Defoix, C, Di Marco, R, Di Capua, E, Diez Hedo, F J, Dolbeau, J, Dumarchez, J, Eriksson, M, Falciano, S, Fernández, C, Fisher, Colin M, Fisyak, Yu V, Fontanelli, F, Fry, J R, Ganguli, S N, Gasparini, U, Gensch, Ulrich, Gentile, S, Gibaut, D B, Goshaw, A T, Grard, F, Gurtu, A, Hamatsu, R, Haupt, L, Hellman, S, Henri, V, Hernández, J J, Holmgren, S O, Houlden, M A, Hrubec, Josef, Hughes, P, Huss, D, Iga, Y, Iori, M, Jegham, E, Johansson, E K, Josa-Mutuberria, I, Kalelkar, M S, Kistenev, E P, Kitamura, S, Knauss, D, Kniazev, V V, Kowald, W, Kuhn, D, Laloum, M, Legros, P, Leutz, H, Lyons, L, MacDermott, M, Mason, P, Mazzucato, M, Michalon, A, Michalon-Mentzer, M E, Moa, T, Monge, R, Montanet, Lucien, Naumann, T, Neuhofer, Günther, Nguyen, H K, Nilsson, S, Nowak, H, Oshima, N, Otter, Gerd, Ouared, R, Panella Comellas, J, Patel, G, Pernicka, Manfred, Pilette, P, Piredda, G, Plano, R J, Poppleton, Alan, Poropat, P, Raghavan, R, Reucroft, S, Roberts, K, Robertson, W J, Rohringer, Herbert, Roth, A E, Salicio, J M, Schulte, R, Sessa, M I, Squarcia, S, Shankar, K, Stammer, P, Stopchenko, V A, Stuczinski, W, Subramanian, A, Sudhakar, K, Takahashi, K, Touboul, M C, Trevisan, U, Troncon, C, Tsurugai, T, Vlasov, E V, Vilain, P, Voltolini, C, Walker, W D, Wild, C F, Vonck, B, Zumerle, G, Aguilar Benitez, M., and Canale, Vincenzo

Subjects
Nuclear physics, Quantum chromodynamics, Physics, Quark, Nuclear and High Energy Physics, Particle physics, Distribution (mathematics), Meson, D meson, Production (computer science), Charm (quantum number), Particle Physics - Experiment
Abstract

Results of fitting the differential distributions in xF and pT2 of D mesons produced in 400 GeV/c p-p interactions to the form d 2 σ d x F d p T 2 ∝(1−x F ) n exp [−(p T 2 /〈p T 2 〉)] are discussed. The D+ distribution is found to be relatively hard [n=3.1±0.8〈Pt2〉=1.32±0.27 (GeV/c)2] and the D0 distribution relatively soft [n=8.1±1.9,〈pT2〉=0.62±0.14 (GeV/c)2] compared to the average for all D's [n=4.9±0.5,〈pT2〉=0.99±0.10 (GeV/c)2]. It is suggested that these distributions could reflect contribution of leading di-quarks in pp collisions. Comparison is made with evidence for leading quarks in charm production in 360 GeV/cπ−p interactions.

Published
1988

15. Study of the rho'(1600) mass region using gamma.p --> pi+pi-p at 20 GeV

Author

Abe, K, Bacon, Trevor C, Ballam, J, Bevan, A V, Bingham, Harry H, Brau, J E, Braune, K, Brick, D H, Bugg, W M, Butler, J M, Cameron, W, Cohn, H O, Colley, D C, Dado, S, Diamond, R, Dingus, P J, Erickson, R, Field, R C, Franek, B J, Fujiwara, N, Gearhart, R A, Glanzman, T, Goldberg, J, Goshaw, A T, Hall, G, Hancock, E R, Handler, T, Hargis, H J, Hart, E L, Hasegawa, K, Hulsizer, R I, Jobes, M, Kafka, T, Kalmus, George Ernest, Kelsey, D P, Kitagaki, T, Kowald, W, Levy, A, Lucas, P W, Mann, W A, McCrory, E S, Merenyi, R, Milburn, R H, Milstene, C, Moffeit, K C, Murray, J J, Napier, A, Noguchi, S, Ochiai, F, O'Neale, S W, Palounek, A P T, Pless, I A, Rankin, P, Robertson, W J, Sagawa, H, Sato, T, Schneps, J, Sewell, S J, Shank, J T, Shapiro, A M, Sugahara, R, Suzuki, A, Takahashi, K, Tamai, K, Tanaka, S, Tether, S, Walker, W D, Widgoff, M, Wilkins, C G, Wolbers, S, Woods, C A, Yamaguchi, A, Yamamoto, R K, Yamashita, S, Yoshimura, Y, Yost, G P, and Yuta, H

Subjects
Particle Physics - Experiment
Published
1984

18. A comparison of the effects of halothane and methoxyflurane on the isolated perfused canine liver.

Author

Coultas RJ, Strunin L, Walker WD, Strunin JM, Reynard A, and Simpson BR

Subjects
Animals, Aspartate Aminotransferases analysis, Bile metabolism, Depression, Chemical, Dogs, Hypercapnia, Hypotension, Hypoxia, In Vitro Techniques, Liver analysis, Liver metabolism, Oxygen Consumption, Perfusion, Potassium analysis, Halothane pharmacology, Liver drug effects, Methoxyflurane pharmacology
Published
1969

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