Atomic mass dependence of Xi- and anti-Xi+ production in central 250-GeV pi- nucleon interactions.

The Fermilab E769 collaboration Alves, G.A. ; Amato, S. ; Anjos, J.C. ; et al.
Phys.Rev.D 56 (1997) 6003-6005, 1997.
Inspire Record 441682 DOI 10.17182/hepdata.42209

We present the first measurement of the atomic mass dependence of central \Xi~- and \overline{\Xi}~+ production. It is measured using a sample of 22,459 \Xi~-'s and \overline{\Xi}~+'s produced in collisions between a 250 GeV \pi~- beam and targets of beryllium, aluminum, copper, and tungsten. The relative cross sections are fit to the two parameter function \sigma_0 A~\alpha, where A is the atomic mass. We measure \alpha = 0.924+-0.020+-0.025, for Feynman-x in the range -0.09 < x_F < 0.15.

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Asymmetries in the production of Lambda0 in 250-GeV/c pi+-, K+- and p nucleon interactions.

The E769 collaboration Alves, G.A ; Amato, S ; Anjos, J.C ; et al.
Phys.Lett.B 559 (2003) 179-186, 2003.
Inspire Record 615414 DOI 10.17182/hepdata.41928

Using data from Fermilab fixed-target experiment E769, we have measured particle-antiparticle production asymmetries for Lambda0 hyperons in 250 GeV/c pi+-, K+- and p -- nucleon interactions. The asymmetries are measured as functions of Feynman-x (x_F) and p_t^2 over the ranges -0.12<=x_F<=0.12 and 0<=p_t^2<=3 (GeV/c)^2 (for positive beam) and -0.12<=x_F<=0.4 and 0<=p_t^2<=10 (GeV/c)^2 (for negative beam). We find substantial asymmetries, even at x_F around zero. We also observe leading-particle-type asymmetries. These latter effects are qualitatively as expected from valence-quark content of the target and variety of projectiles studied.

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Mass splitting and production of sigma(c)0 and sigma(c)++ measured in 500-GeV pi- n interactions

The E791 collaboration Aitala, E.M. ; Amato, S. ; Anjos, J.C. ; et al.
Phys.Lett.B 379 (1996) 292-298, 1996.
Inspire Record 417432 DOI 10.17182/hepdata.16213

>From a sample of $2722 \pm 78$ $\Lambda_c~+$ decaying to the $pK~-\pi~+$ final state, we have observed, in the hadroproduction experiment E791 at Fermilab, $143 \pm 20$ $\Sigma_c~0$ and $122 \pm 18$ $\Sigma_c~{++}$ through their decays to $\Lambda_c~+ \pi~{\pm}$. The mass difference $M(\Sigma_c~0) - M(\Lambda_c~+$) is measured to be $(167.38\pm 0.29\pm 0.15)\,\mbox{MeV}$; for $M(\Sigma_c~{++}) - M(\Lambda_c~+)$, we find $(167.76\pm 0.29\pm0.15)\,\mbox{MeV}$. The rate of $\Lambda_c~+$ production from decays of the $\Sigma_c$ triplet is $(22\pm 2\pm 3)\,\mbox{\%}$ of the total $\Lambda_c~+$ production assuming equal rate of production from all three, as measured for $\Sigma_c~0$ and $\Sigma_c~{++}$. We do not observe a statistically significant $\Sigma_c$ baryon-antibaryon production asymmetry. The $x_F$ and $p_t~2$ spectra of $\Lambda_c~+$ from $\Sigma_c$ decays are observed to be similar to those for all $\Lambda_c~+$'s produced.

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Asymmetries between the production of D+ and D- mesons from 500-GeV/c pi- - nucleon interactions as a function of xF and p(t)**2

The E791 collaboration Aitala, E.M. ; Amato, S. ; Anjos, J.C. ; et al.
Phys.Lett.B 371 (1996) 157-162, 1996.
Inspire Record 415081 DOI 10.17182/hepdata.41684

We present asymmetries between the production of D+ and D- mesons in Fermilab experiment E791 as a function of xF and pt**2. The data used here consist of 74,000 fully-reconstructed charmed mesons produced by a 500 GeV/c pi- beam on C and Pt foils. The measurements are compared to results of models which predict differences between the production of heavy-quark mesons that have a light quark in common with the beam (leading particles) and those that do not (non-leading particles). While the default models do not agree with our data, we can reach agreement with one of them, PYTHIA, by making a limited number of changes to parameters used.

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Measurement of the form-factor ratios for D/s+ --> Phi l+ nu/l.

The E791 collaboration Aitala, E.M. ; Amato, S. ; Anjos, J.C. ; et al.
Phys.Lett.B 450 (1999) 294-300, 1999.
Inspire Record 480733 DOI 10.17182/hepdata.42137

We have measured the form factor ratios r_V = V(0)/A_1(0) and r_2 = A_2(0)/A_1(0) for the decay D_s^+ -> phi ell^+ nu_ell, phi -> K^+ K^-, using data from charm hadroproduction experiment E791 at Fermilab. Results are based on 144 signal and 22 background events in the electron channel and 127 signal and 34 background events in the muon channel. We combine the measurements from both lepton channels to obtain r_V = 2.27 +- 0.35 +- 0.22 and r_2 = 1.57 +- 0.25 +- 0.19.

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Total forward and differential cross sections of neutral D mesons produced in 500-GeV/c pi- nucleon interactions.

The E791 collaboration Aitala, E.M ; Amato, S ; Anjos, J.C ; et al.
Phys.Lett.B 462 (1999) 225-236, 1999.
Inspire Record 502166 DOI 10.17182/hepdata.42103

We measure the neutral D total forward cross section and the differential cross sections as function of Feynman-x ($x_F$) and transverse momentum squared for 500 GeV/c $\pi^-$-nucleon interactions. The results are obtained from 88990+-460 reconstructed neutral D mesons from Fermilab experiment E791 using the decay channels $D\to K^-\pi^+$ and $D\to K^-\pi^+\pi^-\pi^+$ (and charge conjugates). We extract fit parameters from the differential cross sections and provide the first direct measurement of the turnover point in the $x_F$ distribution, 0.0131+-0.0038. We measure an absolute $D^0 + \bar{D^0}$ ($x_F > 0$) cross section of 15.4+1.8-2.3 microbarns/nucleon (assuming a linear A dependence). The differential and total forward cross sections are compared to theoretical predictions and to results of previous experiments.

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Observation of D-pi Production Correlations in 500 GeV pi- - N Interactions

The E791 collaboration Aitala, E.M. ; Amato, S. ; Anjos, J.C. ; et al.
Phys.Lett.B 403 (1997) 185-190, 1997.
Inspire Record 422245 DOI 10.17182/hepdata.42255

We study the charge correlations between charm mesons produced in 500 GeV pi- - N interactions and the charged pions produced closest to them in phase space. With 110,000 fully reconstructed D mesons from experiment E791 at Fermilab, the correlations are studied as functions of the Dpi - D mass difference and of Feynman x. We observe significant correlations which appear to originate from a combination of sources including fragmentation dynamics, resonant decays, and charge of the beam.

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Asymmetries in the production of Lambda/c+ and Lambda/c- baryons in 500-GeV/c pi- nucleon interactions.

The E791 collaboration Aitala, E.M ; Amato, S ; Anjos, J.C ; et al.
Phys.Lett.B 495 (2000) 42-48, 2000.
Inspire Record 531814 DOI 10.17182/hepdata.50150

We present a measurement of asymmetries in the production of $\Lambda_c^+$ and $\Lambda_c^-$ baryons in 500 GeV/c $\pi^-$--nucleon interactions from the E791 experiment at Fermilab. The asymmetries were measured as functions of Feynman x ($x_F$) and transverse momentum squared ($p_T^2$) using a sample of $1819 \pm 62$ $\Lambda_c$'s observed in the decay channel $\Lambda_c \to pK^-\pi^+$. We observe more $\Lambda_c^+$ than $\Lambda_c^-$ baryons, with an asymmetry of $(12.7\pm3.4\pm1.3) %$ independent of $x_F$ and $p_T^2$ in our kinematical range $(-0.1 < x_F < 0.6$ and $0.0 < p_T^2 < 8.0 (GeV/c)^2$). This $\Lambda_c$ asymmetry measurement is the first with data in both the positive and negative $x_F$ regions.

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Differential cross sections, charge production asymmetry, and spin-density matrix elements for D*(2010)+- produced in 500-GeV/c pi- nucleon interactions.

The Fermilab E791 collaboration Aitala, E.M ; Amato, S ; Anjos, J.C ; et al.
Phys.Lett.B 539 (2002) 218-226, 2002.
Inspire Record 587686 DOI 10.17182/hepdata.42892

We report differential cross sections for the production of D*(2010) produced in 500 GeV/c pi^- nucleon interactions from experiment E791 at Fermilab, as functions of Feynman-x (x_F) and transverse momentum squared (p_T^2). We also report the D* +/- charge asymmetry and spin-density matrix elements as functions of these variables. Investigation of the spin-density matrix elements shows no evidence of polarization. The average values of the spin alignment are \eta= 0.01 +- 0.02 and -0.01 +- 0.02 for leading and non-leading particles, respectively.

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Asymmetries between the production of D(s)- and D(s)+ mesons from 500-Gev/c pi- nucleon interactions as functions of x(F) and p-transverse**2

The E791 collaboration Aitala, E.M. ; Amato, S. ; Anjos, J.C. ; et al.
Phys.Lett.B 411 (1997) 230-236, 1997.
Inspire Record 447720 DOI 10.17182/hepdata.42197

This paper presents measurements of the production of Ds- mesons relative to Ds+ mesons as functions of x_F and square of p_t for a sample of 2445 Ds decays to phi pi. The Ds mesons were produced in Fermilab experiment E791 with 500 GeV/c pi- mesons incident on one platinum and four carbon foil targets. The acceptance-corrected integrated asymmetry in the x_F range -0.1 to 0.5 for Ds+- mesons is 0.032 +- 0.022 +- 0.022, consistent with no net asymmetry. The results, as functions of x_F and square of p_t, are compared to predictions and to the large production asymmetry observed for D+- mesons in the same experiment. These comparisons support the hypothesis that production asymmetries come from the fragmentation process and not from the charm quark production itself.

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Asymmetries in the production of Lambda0, Xi-, and Omega- hyperons in 500-GeV/c pi- nucleon interactions.

The E791 collaboration Aitala, E.M. ; Amato, S. ; Anjos, J.C. ; et al.
Phys.Lett.B 496 (2000) 9-18, 2000.
Inspire Record 532973 DOI 10.17182/hepdata.42997

Using data from Fermilab fixed-target experiment E791, we have measured particle-antiparticle production asymmetries for lambda zero, cascade minus, and omega minus hyperons in pi minus-nucleon interactions at 500 GeV/c. The asymmetries are measured as functions of Feynman-x (x_F) and pt^2 over the ranges of -0.12 GE x_F LE 0.12 and 0 GE pt^2 LE 4 (GeV/c)^2. We find substantial asymmetries, even at x_F = 0. We also observe leading-particle- type asymmetries which qualitatively agree with theoretical predictions.

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Search for CP violation in D0 and D+ decays.

The FOCUS collaboration Link, J.M. ; Paolone, V.S. ; Reyes, M. ; et al.
Phys.Lett.B 491 (2000) 232-239, 2000.
Inspire Record 527840 DOI 10.17182/hepdata.42984

A high statistics sample of photoproduced charm particles from the FOCUS (E831) experiment at Fermilab has been used to search for CP violation in the Cabibbo suppressed decay modes D+ to K-K+pi+, D0 to K-K+ and D0 to pi-pi+. We have measured the following CP asymmetry parameters: A_CP(K-K+pi+) = +0.006 +/- 0.011 +/- 0.005, A_CP(K-K+) = -0.001 +/- 0.022 +/- 0.015 and A_CP(pi-pi+) = +0.048 +/- 0.039 +/- 0.025 where the first error is statistical and the second error is systematic. These asymmetries are consistent with zero with smaller errors than previous measurements.

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A Luminosity Independent Measurement of the $\bar{p} p$ Total Cross-section at $\sqrt{s}=1$.8-tev

The E-710 collaboration Amos, Norman A. ; Avila, C. ; Baker, W.F. ; et al.
Phys.Lett.B 243 (1990) 158-164, 1990.
Inspire Record 27474 DOI 10.17182/hepdata.29696

We report a measurement of the p p total cross section at √ s =1.8 TeV using a luminosity-independent method. Our result is σ T =72.1±3.3 mb ; we also derive the total elastic cross section σ el =16.6±1.6 mb. A value is obtained for the total single diffraction cross section of 11.7±2.3 mb.

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Study of the high mass dimuon continuum in 400-GeV proton - nucleus collisions

Kaplan, D.M. ; Fisk, R.J. ; Ito, A.S. ; et al.
Phys.Rev.Lett. 40 (1978) 435, 1978.
Inspire Record 122485 DOI 10.17182/hepdata.20947

The mass spectrum of muon pairs in the range 5 to 15 GeV is studied in the inclusive reaction p+nucleus→μ++μ−+anything. The ϒ and continuum distribution are presented as is the A dependence of the continuum. Comparison with a parton-annihilation model yields a sea-quark distribution.

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Observation of a dimuon resonance at 9.5-GeV in 400-GeV proton - nucleus collisions

The E288 collaboration Herb, S.W. ; Hom, D.C. ; Lederman, L.M. ; et al.
Phys.Rev.Lett. 39 (1977) 252-255, 1977.
Inspire Record 120368 DOI 10.17182/hepdata.42613

Dimuon production is studied in 400-GeV proton-nucleus collisions. A strong enhancement is observed at 9.5 GeV mass in a sample of 9000 dimuon events with a mass $m_{\mu^+\mu^-} \to$ 5 GeV.

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Study of scaling in hadronic production of dimuons

Yoh, J.K. ; Herb, S.W. ; Hom, D.C. ; et al.
Phys.Rev.Lett. 41 (1978) 684, 1978.
Inspire Record 130804 DOI 10.17182/hepdata.3337

We present proton-nucleus dimuon-production cross sections for masses between 4 and 15 GeV, center-of-mass rapidities between -0.23 and 0.6 and incident energies of 200, 300, and 400 GeV. The data confirm scaling to the 20% level. The dependence of continuum 〈pT〉 on beam energy is also presented.

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Elastic Scattering Measurement of the Negative Pion Radius

Dally, E.B. ; Hauptman, J.M. ; Kubic, J. ; et al.
Phys.Rev.Lett. 48 (1982) 375-378, 1982.
Inspire Record 177923 DOI 10.17182/hepdata.20609

A new measurement of the elastic scattering of 250-GeV/c negative pions by electrons provides form-factor results from 0.0368<q2<0.0940 (GeV/c)2. These measurements determine the mean square pion radius to be 〈rπ2〉=0.439±0.030 fm2 or 〈rπ2〉12=0.663±0.023 fm. Comparisons are made with previous elastic-scattering experiments as well as with results obtained from electroproduction experiments, e+e− annihilation experiments, and phenomenological analyses.

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A Prompt photon cross-section measurement in anti-p p collisions at s**(1/2) = 1.8-TeV

The CDF collaboration Abe, F. ; Albrow, M. ; Amidei, D. ; et al.
Phys.Rev.D 48 (1993) 2998-3025, 1993.
Inspire Record 353026 DOI 10.17182/hepdata.22677

The first prompt photon measurement from the CDF experiment at the Fermilab pp¯ Collider is presented. Two independent methods are used to measure the cross section: one for high transverse momentum (PT) and one for lower PT. Comparisons to various theoretical calculations are shown. The cross section agrees qualitatively with QCD calculations but has a steeper slope at low PT.

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Measurement of the dijet mass distribution in p anti-p collisions at s**(1/2) = 1.8-TeV

The CDF collaboration Abe, F. ; Albrow, M. ; Amidei, D. ; et al.
Phys.Rev.D 48 (1993) 998-1008, 1993.
Inspire Record 353889 DOI 10.17182/hepdata.22573

The dijet invariant mass distribution has been measured in the region between 120 and 1000 GeV/c2, in 1.8-TeV pp¯ collisions. The data sample was collected with the Collider Detector at Fermilab (CDF). Data are compared to leading order (LO) and next-to-leading order (NLO) QCD calculations using two different clustering cone radii R in the jet definition. A quantitative test shows good agreement of data with the LO and NLO QCD predictions for a cone of R=1. The test using a cone of R=0.7 shows less agreement. The NLO calculation shows an improvement compared to LO in reproducing the shape of the spectrum for both radii, and approximately predicts the cone size dependence of the cross section.

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A Measurement of sigma B (W ---> e neutrino) and sigma B (Z0 ---> e+ e-) in anti-p p collisions at s**(1/2) = 1800-GeV

The CDF collaboration Abe, F. ; Amidei, D. ; Apollinari, G. ; et al.
Phys.Rev.D 44 (1991) 29-52, 1991.
Inspire Record 302820 DOI 10.17182/hepdata.42696

An analysis of high-transverse-momentum electrons using data from the Collider Detector at Fermilab (CDF) of p¯p collisions at s=1800 GeV yields values of the production cross section times branching ratio for W and Z0 bosons of σ(p¯p→WX→eνX)=2.19±0.04(stat)±0.21(syst) nb and σ(p¯p→Z0X→e+e−X)=0.209±0.013(stat)±0.017(syst) nb. Detailed descriptions of the CDF electron identification, background, efficiency, and acceptance are included. Theoretical predictions of the cross sections that include a mass for the top quark larger than the W mass, current values of the W and Z0 masses, and higher-order QCD corrections are in good agreement with these measured values.

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Scaling properties of high mass symmetric hadron and pion pair production in proton - beryllium collisions

Jostlein, H. ; Engelmann, Roderich J. ; Fisk, R.J. ; et al.
Phys.Rev.Lett. 42 (1979) 146, 1979.
Inspire Record 132764 DOI 10.17182/hepdata.42603

We present measurements of the production symmetric high-mass hadron and pion pairs by protons of 200, 300, and 400 GeV, incident on a beryllium target. The two-particle invariant cross section for pion production can be described by the function E1E2d6σdp13dp23=(1.7×10−28)pt−8.4(1−xt)14 cm2/GeV4 (where pt is the mean pt of the two hadrons). Functions of the same form have been used in describing single-pion inclusive production. Equality of the exponents of pt in the two processes is observed, confirming the role of smearing contributions to single-hadron cross sections.

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Cross-section Measurements for the Reactions $\nu p \to \mu^- \pi^+ p$ and $\nu p \to \mu^- K^+ p$ at High-Energies

Bell, J. ; Coffin, C.T. ; Diamond, R.N. ; et al.
Phys.Rev.Lett. 41 (1978) 1008, 1978.
Inspire Record 131344 DOI 10.17182/hepdata.24326

We present results for the reactions νp→μ−π+p and νp→μ−K+p at energies above 5 GeV. The average cross section for the first reaction between 15 and 40 GeV is (0.80±0.12) × 10−38 cm2 and for events with Mπ+p<1.4 GeV is (0.55±0.08) × 10−38 cm2. The ratio of the cross section for the second reaction to that for the first is 0.017±0.010.

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Measurement of the ratio sigma B (W ---> e neutrino) / sigma B (Z0 ---> e+ e-) in anti-p p collisions at s**(1/2) = 1.8-TeV

The CDF collaboration Abe, F. ; Albrow, M. ; Amidei, D. ; et al.
Phys.Rev.Lett. 73 (1994) 220-224, 1994.
Inspire Record 373743 DOI 10.17182/hepdata.50100

We present a measurement of the ratio σB(W→eν)σB(Z0→e+e−) in p¯p collisions at s=1.8 TeV The data represent an integrated luminosity of 21.7 pb−1 from the 1992-1993 run of the Collider Detector at Fermilab. We find σB(W→eν)σB(Z0→e+e−)=10.90±0.32(stat)±0.29(syst). From this value, we extract a value for the W width, Γ(W)=2.064±0.061(stat)±0.059(syst) GeV, and the branching ratio, Γ(W→eν)Γ(W)=0.1094±0.0033(stat)±0.0031(syst), and we set a decay-mode-independent limit on the top quark mass mtop>62 GeV/c2 at the 95% C.L.

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High Transverse Momentum Single Hadron Production in p p and p d Collisions at s**1/2 = 27.4-GeV and s**1/2 = 38.8-GeV

Jaffe, D.E. ; Straub, P.B. ; Adams, M.R. ; et al.
Phys.Rev.D 40 (1989) 2777, 1989.
Inspire Record 278691 DOI 10.17182/hepdata.23016

Results of high-transverse-momentum charged-hadron production in 400-GeV/c proton-proton and proton-deuteron collisions and 800-GeV/c proton-proton collisions are presented. The transverse-momentum range of the data is from 5.2 to 9.0 GeV/c for the 400-GeV/c collisions and from 3.6 to 11.0 GeV/c for the 800-GeV/c collisions; the data are centered around 90° in the proton-nucleon center-of-momentum system. Single-pion invariant cross sections and particle ratios were measured at both energies. The results are compared to previous experiments and the Lund model.

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Particle ratios of high x(t) hadrons in p A interactions at s**(1/2) = 38.8-GeV.

Straub, P.B. ; Jaffe, D.E. ; Glass, H.D. ; et al.
Phys.Rev.D 45 (1992) 3030-3037, 1992.
Inspire Record 342598 DOI 10.17182/hepdata.22727

We report measurements of the ratios K+π+, pπ+, K−π−, p¯π−, π−π+, K−K+, and p¯p for hadrons with 0.19<xt<0.62 produced in p−Be and p−W collisions at s=38.8 GeV. The K+π+ ratio at high xt gives the fragmentation-function ratio DuK+Duπ+ at high z. The high-xt K−π− ratio gives an upper limit for DdK−Ddπ− at high z. The pt dependence of pπ+ suggests that scattered constituent diquarks are the primary source of protons with pt<6 GeV/c. We also present species correlations in high-mass h+h− pairs. Strong K+K− and pp¯ correlations were observed.

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