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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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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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 $x_F$ 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 lepton+ neutrino(lepton)

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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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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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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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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Differential Cross-Sections, Charge Production Asymmetry, and Spin Density Matrix Elements for $D^{*\pm}$(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 in the production of Lambda0, Xi-, and Omega- hyperons in 500-GeV/c pi minus: 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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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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Photoproduction of D mesons

The E-687 collaboration Buchholz, D. ; Frabetti, P.L. ; Bogart, C.W. ; et al.
1990.
Inspire Record 300996 DOI 10.17182/hepdata.43002
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Inclusive charged pion production in hadron nucleus interactions at 100-GeV/c and 320-GeV/c

Whitmore, J.J. ; Persi, F. ; Toothacker, W.S. ; et al.
Z.Phys.C 62 (1994) 199-227, 1994.
Inspire Record 378192 DOI 10.17182/hepdata.14207

An experiment has been performed with the Fermilab 30-inch bubble chamber and Downstream Particle Identifier to study inclusive charged pion production in the high energy interactions of π±,K+,p and\(\bar p\) with thin foils of magnesium, silver and gold. The laboratory rapidity and transverse momentum distributions are presented separately for π+ and π− production. Comparisons are made with data from hadron-proton interactions and theA dependence of the cross sections in the different kinematic regions is discussed. We investigate the dependence of the cross sections on the number of observed protons ejected from the nucleus. By using our π−A data from two different beam energies, we study the energy dependence of these spectra. Comparisons are made with the VENUS string model Monte Carlo.

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phi meson production from p anti-p collisions at s**(1/2) = 1.8-TeV

The E735 collaboration Alexopoulos, T. ; Allen, C. ; Anderson, E.W. ; et al.
Z.Phys.C 67 (1995) 411-416, 1995.
Inspire Record 405368 DOI 10.17182/hepdata.14115

Fermilab experiment E735 located at the CO intersection region of the\(\sqrt s= 1.8\) TeV\(p\bar p\) collider analysed over 900 Φ→K+K− events. Measured were the transverse momentum spectrum, the correlation between the average transverse momentum <pt> and the charged particle multiphcityNc, as well as the probability of Φ production per charged track,NΦ/Nc, versusNc. We have also made an estinate of the total inclusive cross section for Φ mesons,\(\sigma (p\bar p \to \phi X) = 7.3 \pm 2.2 mb\).

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Large x(F) spin asymmetry in pi0 production by 200-GeV polarized protons

The E581 & E704 collaborations Adams, D.L. ; Akchurin, N. ; Belikov, N.I. ; et al.
Z.Phys.C 56 (1992) 181-184, 1992.
Inspire Record 314230 DOI 10.17182/hepdata.14557

The spin asymmetryAN for inclusive π0 production by 200-GeV transversely-polarized protons on a liquid hydrogen target has been measured at Fermilab over a wide range ofxF, with 0.5<pT<2 GeV/c. AtxF>0.3, the asymmetry rises with increasingxF and reaches a value ofAN=0.15±0.03 in the region 0.6<xF<0.8. This result provides new input regarding the question of the internal spin structure of transversely-polarized protons.

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Production of $\pi^0$ and $\eta$ mesons at large transverse momenta in $pp$ and $pBe$ Interactions at 530 and 800 GeV/c.

The Fermilab E706 collaboration Apanasevich, L. ; Bacigalupi, J. ; Baker, W. ; et al.
Phys.Rev.D 68 (2003) 052001, 2003.
Inspire Record 585866 DOI 10.17182/hepdata.11186

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.

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Precise measurement of neutrino and anti-neutrino differential cross sections

The NuTeV collaboration Tzanov, M. ; Naples, D. ; Boyd, S. ; et al.
Phys.Rev.D 74 (2006) 012008, 2006.
Inspire Record 691719 DOI 10.17182/hepdata.11120

The NuTeV experiment at Fermilab has obtained a unique high statistics sample of neutrino and anti-neutrino interactions using its high-energy sign-selected beam. We present a measurement of the differential cross section for charged-current neutrino and anti-neutrino scattering from iron. Structure functions, F_2(x,Q^2) and xF_3(x,Q^2), are determined by fitting the inelasticity, y, dependence of the cross sections. This measurement has significantly improved systematic precision as a consequence of more precise understanding of hadron and muon energy scales.

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Backward emitted protons in interactions of neutrinos with nuclei in photoemulsion. FNAL-564 experiment

Dayon, M. ; Rappoport, V. ; Smirnitsky, V. ; et al.
Z.Phys.C 56 (1992) 391-393, 1992.
Inspire Record 345621 DOI 10.17182/hepdata.14532

Backward emitted protons with momentump>0.3 GeV/c in interactions of neutrino in the energy range 10–200 GeV with photoemulsion nuclei were investigated. Energy spectrum slope parameter of backward protons was measured to beT0=48.9±7.9 MeV. TheA-dependence power index of relative mean yield of backward protons was found to bea=0.68±0.12. A drop in the mean yield of backward protons at the four momentum squared over ∼15 (GeV/c)2 (the neutrino energy over ∼50 GeV) was observed.

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THREE PION PRODUCTION ON NUCLEI AT 200-GEV

Zielinski, M. ; Berg, D. ; Chandlee, C. ; et al.
Z.Phys.C 16 (1983) 197-204, 1983.
Inspire Record 190869 DOI 10.17182/hepdata.16390

We have carried out a systematic study of the coherent dissociation of pions into 3 pions using nuclear targets. The experiment was performed at Fermilab using a high resolution forward spectrometer. Data were taken with carbon, copper and lead targets at an incident momentum of 202.5 GeV/c. Results are presented on momentum transfers, 3-pion masses, and on the nuclearA-dependence of the production cross section.

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Negative Hyperon Production in High-Energy Proton Interactions

Hungerbuhler, V. ; Majka, R. ; Marx, J.N. ; et al.
Phys.Rev.D 12 (1975) 1203-1210, 1975.
Inspire Record 104138 DOI 10.17182/hepdata.4668

Momentum spectra for forward Σ− and Ξ− production by protons on beryllium are presented. Σ− production data for two primary proton momenta are compared to test scaling of the invariant cross section. In addition, the observed single-particle momentum distributions are compared with single-particle spectra from other inclusive reactions initiated by protons.

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Multiplicity of Charged Particles in 800-{GeV} $p p$ Interactions

The LEBC-MPS collaboration Ammar, R. ; Aziz, T. ; Banerjee, S. ; et al.
Phys.Lett.B 178 (1986) 124-128, 1986.
Inspire Record 231133 DOI 10.17182/hepdata.6558

Results are reported concerning the charged-particle multiplicity distribution obtained in an exposure of the high-resolution hydrogen bubble chamber LEBC to a beam of 800 GeV protons at the Fermilab MPS. This is the first time that such data have been available at this energy. The distribution of the number n ch of charged particles produced in inelastic interactions obeys KNO-scaling. The average multiplicity is 〈 n ch 〉 = 10.26±0.15. For n ch ⩾8 the data can be well fitted to a negative binomial. The difference between the overall experimental multiplicity distribution and that resulting from the latter fit is in agreement with the contribution expected from diffractive processes.

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Measurement of the Difference in R = $\sigma^-$l / $\sigma^-$t and $\sigma$(a) / $\sigma(D$) in Deep Inelastic $e D$, $e$ Fe and $e$ Au Scattering

Dasu, S. ; de Barbaro, P. ; Bodek, A. ; et al.
Phys.Rev.Lett. 60 (1988) 2591, 1988.
Inspire Record 260760 DOI 10.17182/hepdata.20155

We measured the differences in R=σLσT and the cross-section ratio σAσD in deep-inelastic electron scattering from D, Fe, and Au nuclei in the kinematic range 0.2≤x≤0.5 and 1≤Q2≤5 (Gev/c)2. Our results for RA−RD are consistent with zero for all x and Q2, indicating that possible contributions to R from nuclear higher-twist effects and spin-0 constituents in nuclei are not different from those in nucleons. The European Muon Collaboration effect is reconfirmed, and the low-x data from all recent experiments, at all Q2, are now in agreement.

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Continuum Dimuon Production in $\bar{p} W$ Collisions at 125-GeV/c

Anassontzis, E. ; Katsanevas, S. ; Kostarakis, P. ; et al.
Phys.Rev.Lett. 54 (1985) 2572, 1985.
Inspire Record 213694 DOI 10.17182/hepdata.20379

The cross section for the reaction p¯N→μ+μ−X with muon pairs in the mass range 4<M<9 GeV/c2 and xF>0 was measured to be σ=0.104±0.005±0.008 nb/nucleon. The distributions dσdxF and M3dσdM were compared to the QCD-improved Drell-Yan model and to calculations including first-order QCD corrections, with use of deep-inelastic structure functions. Excellent agreement with the data was obtained if the calculations were multiplied by factors of 2.45 and 1.41, respectively.

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Radiative Width of the $K^*$+ (890)

Chandlee, C. ; Berg, D. ; Cihangir, S. ; et al.
Phys.Rev.Lett. 51 (1983) 168, 1983.
Inspire Record 13393 DOI 10.17182/hepdata.20522

Coherent production of Kπ systems observed in the excitation of 200-GeV/c positive kaons on nuclear targets has been analyzed, including both electromagnetic and strong contributions, to yield a new value for the radiative width for the process K*+(890)→K+γ of 51 ± 5 keV.

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The Inclusive Reactions $p + n \to p + X$ and $\pi^+ + n \to p + X$ at 100-GeV/c

Hanlon, J. ; Brody, A. ; Engelmann, R. ; et al.
Phys.Rev.Lett. 37 (1976) 967, 1976.
Inspire Record 108156 DOI 10.17182/hepdata.21040

We have measured the inclusive cross section for the reactions p+n→p+X and π++n→p+X at 100 GeV/c in the kinematic region |t|<1.0 GeV2. The data were obtained from an exposure of the Fermilab 30-in. deuterium-filled bubble chamber to a tagged positively charged beam. The differential cross sections for these reactions are observed to scale in the ratio of the pn and π+n total cross sections and to be consistent with the predictions of a Reggeized one-pion-exchange model.

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