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Measurement of the longitudinal spin dependent neutron - proton total cross-section difference Delta sigma-L (n p) between 500-MeV - 800-MeV

Beddo, M. ; Burleson, G. ; Faucett, J.A. ; et al.

Phys.Rev.D 50 (1994) 104-123, 1994.

Inspire Record 37179 DOI 10.17182/hepdata.22460

A measurement of ΔσL(np), the difference between neutron-proton total cross sections for pure longitudinal spin states, is described. Data were taken at LAMPF for five neutron beam kinetic energies: 484, 568, 634, 720, and 788 MeV. The statistical errors are in the range of 0.64–1.35 mb. Various sources of systematic effects were investigated and are described. Overall systematic errors are estimated to be on the order of 0.5 mb and include an estimate for the uncertainty in the neutron beam polarization. The ΔσL results are consistent with previous results from PSI and Saclay. These data, when combined with other results and fitted to a Breit-Wigner curve, are consistent with an elastic I=0 resonance with mass 2214±15 (stat) ±6 (syst) MeV and width 75±21±12 MeV. Because of a lack of ΔσT(np) data between 500 and 800 MeV, it is not possible to differentiate between a singlet or coupled-triplet partial wave being responsible.

2 data tables

Table 1

No description provided.

Table 2

The (I=0) part of SIG(NAME=CLL) after subtraction of the p p data, (I=1) part.

rivet Analysis
Observation of gamma gamma ---> phi rho0 and gamma gamma ---> phi omega

The ARGUS collaboration Albrecht, H. ; Ehrlichmann, H. ; Hamacher, T. ; et al.

Phys.Lett.B 332 (1994) 451-457, 1994.

Inspire Record 372451 DOI 10.17182/hepdata.45102

Two-photon production of the hadronic final states K + K − π + π − and K + K − π + π 0 π − has been studied using the ARGUS detector at the e + e − storage ring DORIS II at DESY. The cross sections of the reactions γγ → øϱ 0 and γγ → øω have been measured for the first time. In addition, angular distrubutions have been determined for the reaction γγ → øϱ 0 → K + K − π + π − .

2 data tables

Table 1

No description provided.

Table 2

No description provided.

Observation of the top quark

The D0 collaboration Abachi, S. ; Abbott, B. ; Abolins, M. ; et al.

Phys.Rev.Lett. 74 (1995) 2632-2637, 1995.

Inspire Record 393099 DOI 10.17182/hepdata.42452

The DO collaboration reports on a search for the Standard Model top quark in pbar-p collisions at Sqrt(s)=1.8TeV at the Fermilab Tevatron, with an integrated luminosity of approximately 50pb-1. We have searched for t-tbar production in the dilepton and single-lepton decay channels, with and without tagging of b-quark jets. We observed 17 events with an expected background of 3.8+/-0.6 events. The probability for an upward fluctuation of the background to produce the observed signal is 2.0E-6 (equivalent to 4.6 standard deviations). The kinematic properties of the excess events are consistent with top quark decay. We conclude that we have observed the top quark and measure its mass to be 199~+19_21 (stat.)+/- 22 (syst.)GeV/c**2 and its production cross section to be 6.4 +/- 2.2 pb.

1 data table

Table 1

Cross section refers to top quark mass equal 199. (+19, -21, +- 22) GeV.

Nuclear dependence of J / psi production by 800-GeV/c protons near x(F) = 0

Leitch, M.J. ; Boissevain, J. ; Brown, C.N. ; et al.

Phys.Rev.D 52 (1995) 4251-4253, 1995.

Inspire Record 394199 DOI 10.17182/hepdata.55727

The nuclear dependence for 800 GeV/c proton production of J/ψ’s has been measured near xF=0. $J/ psi—’s produced from beryllium, carbon, and tungsten targets were detected with the Fermilab E789 pair spectrometer. These data extend the results from E772 down to the range xF=-0.1 to 0.1 and indicate a gradually increasing suppression as xF falls below zero.

3 data tables

Table 1

Table 2

Table 3

rivet Analysis
Studies of topological distributions of inclusive the three and four jet events in anti-P P collisions at s**(1/2) = 1800-GeV with the D0 detector

The D0 collaboration Abachi, S. ; Abbott, B. ; Abolins, M. ; et al.

Phys.Rev.D 53 (1996) 6000-6016, 1996.

Inspire Record 399364 DOI 10.17182/hepdata.11124

The global topologies of inclusive three-- and four--jet events produced in $\pp$ interactions are described. The three-- and four--jet events are selected from data recorded by the D\O\ detector at the Tevatron Collider operating at a center--of--mass energy of $\sqrt{s} = 1800$ GeV. The measured, normalized distributions of various topological variables are compared with parton--level predictions of tree--level QCD calculations. The parton--level QCD calculations are found to be in good agreement with the data. The studies also show that the topological distributions of the different subprocesses involving different numbers of quarks are very similar and reproduce the measured distributions well. The parton shower Monte Carlo generators provide a less satisfactory description of the topologies of the three-- and four--jet events.

29 data tables

Table 1

The estimated systematic uncertainty is 6 PCT.

Table 2

The estimated systematic uncertainty is 6 PCT.

Table 3

The estimated systematic uncertainty is 6 PCT.

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Neutron - proton elastic scattering spin - spin correlation parameter. Measurements between 500 and 800 - MeV. 3. Mixtures of C(ss), C(ls), C(ll), and C(nn).

Carlson, V. ; Garnett, R. ; Hill, D. ; et al.

Phys.Rev.D 53 (1996) 3506-3533, 1996.

Inspire Record 404963 DOI 10.17182/hepdata.50927

Measurements are presented for several mixtures of the spin observables CSS,CSL=CLS, CLL, and CNN for neutron-proton elastic scattering. These data were obtained with a free polarized neutron beam, a polarized proton target, and a large magnetic spectrometer for the outgoing proton. The neutron beam kinetic energies were 484, 567, 634, 720, and 788 MeV. Combining these results with earlier measurements allows the determination of the pure spin observables CSS, CLS, and CLL at 484, 634, and 788 MeV for c.m. angles 25°≤θc.m.≤180° and at 720 MeV for 35°≤θc.m.≤80°. These data make a significant contribution to the knowledge of the isospin-0 nucleon-nucleon scattering amplitudes. © 1996 The American Physical Society.

19 data tables

Table 1

Results for the pure spin observables. Statistical errors only. (Data for CSS and CNN at (172.5 to 177.5) and (167.5 to 172.5) degrees are uncertain because of the rapid angular dependence and possible errors in angle, and may be omitted from phase shift analyses.) The CNN data without errors are from a phase shift analysis of Arndt et al. (PR D45 (1992) 3395) [FA92] and were used to derive pure spin observables from the measured data.

Table 2

Table 3

Results for the pure spin observables. Statistical errors only. The CNN data without errors are from a phase shift analysis of Arndt et al. (PR D45 (1992) 3395) [FA92] and were used to derive pure spin observables from the measured data.

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Two measurements of B0 anti-B0 mixing using kaon tagging

The ARGUS collaboration Albrecht, H. ; Hamacher, T. ; Hofmann, R.P. ; et al.

Phys.Lett.B 374 (1996) 256-264, 1996.

Inspire Record 403080 DOI 10.17182/hepdata.28387

Using the ARGUS detector at the e + e − storage ring DORIS II at DESY, we have made two measurements of the mixing parameter χ d using kaons as flavour tags. Using D ∗+ K ± correlations we found χ d = 0.20 ± 0.13 ± 0.12 and from the study of (D ∗+ ℓ − ) K ± correlations we obtained χ d = 0.19 ± 0.07 ± 0.09. The branching ratio for B → D ∗+ X has been updated: Br( B → D ∗+ X) = (19.6 ± 1.9) %. We have also determined the average multiplicity of charged kaons in B 0 decays to be 0.78 ± 0.08.

2 data tables

Table 1

Mixing parameter from counting kaon events. First (...,C=D*+K+-) and second(...,C=(D*+LEPTON-)K+-) value are obtained from a study of D*+K+- and (D*+LEPTO N-)K+- correlations respectively. Second value and the value, reported in Phys.Lett. 324B (1994) 249, were averaged, result third value (...,C=COMBINED) of the mixing parameter in the table (see text for details). In the second value (...,C=(D*+LEPTON-)K+-) the first systematic error is due to the background estimation, the branching ratio for the process B --> K+(K-) X, experimental cuts, and the second one is due to to the uncertainty on the branching ratio for the processes D0 --> K+- X.

Table 2

No description provided.

rivet Analysis
Two photon production of omega pairs

The ARGUS collaboration Albrecht, H. ; Hamacher, T. ; Hofmann, R.P. ; et al.

Phys.Lett.B 374 (1996) 265-270, 1996.

Inspire Record 403304 DOI 10.17182/hepdata.44942

A maximum likelihood analysis of ARGUS data on two-photon production of π + π + π 0 π 0 π − π − is presented. A small fraction of events is due to the production of omega pairs. The γγ → ωω cross section has its maximum value close to threshold.

1 data table

Table 1

Results of maximum liklihood analysis.

Absolute p p elastic cross-sections from 492-MeV to 793-MeV using CH-2 targets

Simon, A.J. ; Glass, G. ; McNaughton, M.W. ; et al.

Phys.Rev.C 53 (1996) 30-34, 1996.

Inspire Record 429629 DOI 10.17182/hepdata.25831

pp-elastic differential cross sections are reported at 492 MeV from 40° to 90°, and at 576, 642, 728, and 793 MeV from 75° to 90° c.m., with an absolute accuracy of less than 1%. These data, obtained with polyethylene targets, agree with recent measurements at the same energies obtained with a liquid-hydrogen target. © 1996 The American Physical Society.

10 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.