Edelstein, R.M.
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Measurement of the t anti-t production cross-section in p anti-p collisions at S**(1/2) = 1.8-TeV

The CDF collaboration Abe, F. ; Akimoto, H. ; Akopian, A. ; et al.
Phys.Rev.Lett. 80 (1998) 2773-2778, 1998.
Inspire Record 449604 DOI 10.17182/hepdata.42178

We present a measurement of the t-tbar cross section in p-pbar collisions at sqrt(s)=1.8 TeV using an integrated luminosity of 109 pb-1 collected with the Collider Detector at Fermilab. The measurement uses t-tbar decays into final states which contain one or two high transverse momentum leptons and multiple jets, and final states which contain only jets. Using acceptances appropriate for a top quark mass of 175 GeV/c^2, we find sigma(t-tbar)=7.6 (+1.8 -1.5) pb .

1 data table
Table 1

SVX (second vertex) and SLT (second lepton) denote different method of b-tagging. Errors shown are statistical and systematical combined in quadrature.


Measurement of the top quark mass and t anti-t production cross-section from dilepton events at the collider detector at Fermilab

The CDF collaboration Abe, F. ; Akimoto, H. ; Akopian, A. ; et al.
Phys.Rev.Lett. 80 (1998) 2779-2784, 1998.
Inspire Record 449926 DOI 10.17182/hepdata.42173

We present an analysis of dilepton events originating from top-antitop production in proton-antiproton collisions at sqrt{s}=1.8 TeV at the Fermilab Tevatron Collider. The sample corresponds to an integrated luminosity of 109+-7 pb^{-1}. We observe 9 candidate events, with an estimated background of 2.4+-0.5 events. We determine the mass of the top quark to be M_top = 161+-17(stat.)+-10(syst.) GeV/c^2. In addition we measure a top-antitop production cross section of 8.2+4.4-3.4 pb (where M_top = 175 GeV/c^2 has been assumed for the acceptance estimate).

1 data table
Table 1

No description provided.


Search for supersymmetry in the photon(s) plus missing energy channels at s**(1/2) = 161-GeV and 172-GeV.

The ALEPH collaboration Barate, R. ; Buskulic, D. ; Decamp, D. ; et al.
Phys.Lett.B 420 (1998) 127-139, 1998.
Inspire Record 449077 DOI 10.17182/hepdata.47381

Searches for supersymmetric particles in channels with one or more photons and missing energy have been performed with data collected by the ALEPH detector at LEP. The data consist of 11.1 pb-1 at $\sqrt{s} = 161 GeV$, 1.1 pb-1 at 170 GeV and 9.5 pb-1 at 172 GeV. The e+e- -> nunu+photon cross section is measured. The data are in good agreement with predictions based on the Standard Model, and are used to set upper limits on the cross sections for anomalous photon production. These limits are compared to two different SUSY models and used to set limits on the neutralino mass. A limit of 71 GeV/c^2 at 95% C.L. is set on the mass of the lightest neutralino ($\tau_{\chi_{1}^{0}} \leq $ 3 ns) for the gauge-mediated supersymmetry breaking and LNZ models.

1 data table
Table 1

No description provided.


Dijet production by color-singlet exchange at the Fermilab Tevatron

The CDF collaboration Abe, F. ; Akimoto, H. ; Akopian, A. ; et al.
Phys.Rev.Lett. 80 (1998) 1156-1161, 1998.
Inspire Record 447619 DOI 10.17182/hepdata.42182

We report a new measurement of dijet production by color-singlet exchange in pp¯ collisions at s=1.8TeV at the Fermilab Tevatron. In a sample of events with two jets of transverse energy ETjet>20GeV, pseudorapidity in the range 1.8<|ηjet|<3.5, and η1η2<0, we find that a fraction R=[1.13±0.12(stat)±0.11(syst)]% has a pseudorapidity gap within |η|<1 between the jets that can be attributed to color-singlet exchnage. The fraction R shows no significant dependence on ETjet or on the pseudorapidity separation between the jets.

1 data table
Table 1

Q=SS and Q=OS means same-side and opposite-side events.


Search for first generation leptoquark pair production in p anti-p collisions at S**(1/2) = 1.8-TeV

The CDF collaboration Abe, F. ; Akimoto, H. ; Akopian, A. ; et al.
Phys.Rev.Lett. 79 (1997) 4327-4332, 1997.
Inspire Record 447250 DOI 10.17182/hepdata.42184

We present a search for first generation leptoquark with 110pb^1 of data collected with the CDF detector. We set 95% C.L. cross section limits as a function of the leptoquark mass.

1 data table
Table 1

It is assumed that first generation scalar leptoquark has the ranching ratio to electron and quark equal to 1.


rivet Analysis
Measurement of the differential cross-section for events with large total transverse energy in p anti-p collisions at s**(1/2) = 1.8-Tev

The CDF collaboration Abe, F. ; Akimoto, H. ; Akopian, A. ; et al.
Phys.Rev.Lett. 80 (1998) 3461-3466, 1998.
Inspire Record 448075 DOI 10.17182/hepdata.42179

We present a measurement of the differential cross section dσ/dΣETjet for the production of multijet events in pp¯ collisions where the sum is over all jets with transverse energy ETjet>ETmin. The measured cross section for events with ΣETjet>320GeV is compared to O(αs3) perturbative QCD predictions and QCD parton shower Monte Carlo predictions. The agreement between the O(αs3) predicted and observed event rates is reasonable for ETmin=100GeV, but poorer for ETmin=20GeV.

2 data tables
Table 1

The ET shown here (unless specified otherwise) is the sum of all the jets' individual ETs. All jets are required to have the absolute values of their pseudorapidity < 4.2 and data are given for two different minimum ET cut-offs.. The errors given are statistical only.

Table 2

Integrated cross sections. Again ET is the sum of the individual ETs of thejets.


Properties of jets in W boson events from 1.8-TeV anti-p p collisions

The CDF collaboration Abe, F. ; Akimoto, H. ; Akopian, A. ; et al.
Phys.Rev.Lett. 79 (1997) 4760-4765, 1997.
Inspire Record 448076 DOI 10.17182/hepdata.54006

We present a study of events with W bosons and hadronic jets produced in pbar p collisions at a center of mass energy of 1.8 TeV. The data consist of 51400 W^+/- -> e^+/- nu decay candidates from 108 pb^-1 of integrated luminosity collected with the CDF detector at the Tevatron Collider. The cross sections and jet production properties have been measured for W + \geq 1 to \geq 4 jet events. The data are compared to predictions of leading order QCD matrix element calculations with added gluon radiation and simulated fragmentation.

10 data tables
Table 1

W and Z0 + njet cross sections.. Data for Z0 read from the plot.

Table 2

ET distribution of the highest ET jet W + >=1jet production. Data read from the plot.

Table 3

ET distribution of the second highest ET jet W + >=2jet production. Data read from the plot.

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The Jet pseudorapidity distribution in direct photon events in p anti-p collisions at S**(1/2) = 1.8-TeV

The CDF collaboration Abe, F. ; Albrow, M.G. ; Amendolia, S.R. ; et al.
Phys.Rev.D 57 (1998) 1359-1365, 1998.
Inspire Record 453369 DOI 10.17182/hepdata.54263

We present the first measurement of the jet pseudorapidity distribution in direct photon events from a sample of pp¯ collisions at s=1.8TeV, recorded with the Collider Detector at Fermilab. Quantum chromodynamics (QCD) predicts that these events are primarily from hard quark-gluon Compton scattering, qg→qγ, with the final state quark producing the jet of hadrons. The jet pseudorapidity distribution in this model is sensitive to parton momentum fractions between 0.015 and 0.15. We find that the shape of the measured pseudorapidity distribution agrees well with next-to-leading order QCD calculations.

1 data table
Table 1

The fully corrected shape of the pseudorapidity distribution normalised to the data in the absolute pseudorapidity bin from 0 to 0.7.


rivet Analysis
Measurements of the meson photon transition form factors of light pseudoscalar mesons at large momentum transfer.

The CLEO collaboration Gronberg, J. ; Hill, T.S. ; Kutschke, Robert K. ; et al.
Phys.Rev.D 57 (1998) 33-54, 1998.
Inspire Record 446031 DOI 10.17182/hepdata.47203

Using the CLEO~II detector, we have measured the differential cross sections for exclusive two-photon production of light pseudoscalar mesons $\pi^0$, $\eta$, and $\eta^{\prime}$. From our measurements we have obtained the form factors associated with the electromagnetic transitions $\gamma^*\gamma$ $\to$ meson. We have measured these form factors in the momentum transfer ranges from 1.5 to 9, 20, and 30 GeV$^2$ for $\pi^0$, $\eta$, and $\eta^{\prime}$, respectively, and have made comparisons to various theoretical predictions.

10 data tables
Table 1

The results of PI0 --> GAMMA GAMMA analysis assuming Br(PI0-->2GAMMA)=0.99.

Table 2

The results of ETA --> GAMMA GAMMA analysis assuming Br(ETA-->2GAMMA)=0.39.

Table 3

The results of ETA --> 3PI0 analysis assuming Br(ETA-->3PI0)*Br(PI0-->2GAM MA)**3 = 0.31.

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rivet Analysis
Measurement of the total cross section for e+ e- --> hadrons at s**(1/2) = 10.52-GeV.

The CLEO collaboration Ammar, R. ; Baringer, Philip S. ; Bean, A. ; et al.
Phys.Rev.D 57 (1998) 1350-1358, 1998.
Inspire Record 445351 DOI 10.17182/hepdata.47132

Using the CLEO detector at the Cornell Electron Storage Ring, we have made a measurement of R=sigma(e+e- ->hadrons)/sigma(e+e- ->mu+mu-) =3.56+/-0.01+/-0.07 at ECM=10.52 GeV. This implies a value for the strong coupling constant of alpha_s(10.52 GeV)=0.20+/-0.01+/-0.06, or alpha_s(M_Z)=0.13+/-0.005+/-0.03.

2 data tables
Table 1

Corrected for background and radiactive effects.

Table 2

Value of ALPHAS, the strong coupling constant, from the measurement of R. CT,= ALPHAS also given evolved to the Z0 mass.