HEPData Search

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Forward - backward charge asymmetry of electron pairs above the Z0 pole

The CDF collaboration Abe, F. ; Akimoto, H. ; Akopian, A. ; et al.

Phys.Rev.Lett. 77 (1996) 2616-2621, 1996.

Inspire Record 417098 DOI 10.17182/hepdata.50121

We present a measurement of the forward-backward charge asymmetry of the process pp¯→Z0/γ+X,Z0/γ→e+e− at Mee>MZ, using 110pb−1 of data at s=1.8TeV collected at the Collider Detector at Fermilab. The measured charge asymmetries are 0.43±0.10 in the invariant mass region Mee>105GeV/c2, and 0.070±0.016 in the region 75<Mee<105GeV/c2. These results are consistent with the standard model values of 0.528±0.009 and 0.052±0.002, respectively.

1 data table

Table 1

The forward-backward asymmetry resuts from angular differential cross section : D(SIG)/D(COS(THETA*) = A*(1 + COS(THETA*)**2) + B*COS(THETA*), where THETA * is the emission angle of the E- relative to the quark momentum in the rest frame of the E+ E- pair.

Study of t anti-t production p anti-p collisions using total transverse energy

The CDF collaboration Abe, F. ; Akimoto, H. ; Akopian, A. ; et al.

Phys.Rev.Lett. 75 (1995) 3997, 1995.

Inspire Record 396003 DOI 10.17182/hepdata.42358

We analyze a sample of W + jet events collected with the Collider Detector at Fermilab (CDF) in ppbar collisions at sqrt(s) = 1.8 TeV to study ttbar production. We employ a simple kinematical variable "H", defined as the scalar sum of the transverse energies of the lepton, neutrino and jets. For events with a W boson and four or more jets, the shape of the "H" distribution deviates by 3.8 standard deviations from that expected from known backgrounds to ttbar production. However this distribution agrees well with a linear combination of background and ttbar events, the agreement being best for a top mass of 180 GeV/c^2.

1 data table

Table 1

A result of the study of the W + >= 4JETS data sample used in PRL 74, 2626, based on 67 pb-1 of integrated luminosity.. Different fit results due to two choices of the Q2 scale in VECBOS program (see paper).

Total cross-section measurements for muon-neutrino, anti-muon-neutrino interactions in 3-GeV - 30-GeV energy range with IHEP-JINR neutrino detector

Anikeev, V.B. ; Belikov, S.V. ; Borisov, A.A. ; et al.

Z.Phys.C 70 (1996) 39-46, 1996.

Inspire Record 400486 DOI 10.17182/hepdata.40711

The results of total cross section measurements for theνμ,$\bar \nu _\mu$ interactions with isoscalar target in the 3 – 30 GeV energy range have been presented. The data were obtained with the IHEP-JINR Neutrino Detector in the “natural” neutrino beams of the U-70 accelerator. Neutrino fluxes were obtained by averaging the spectra, based on the calculations with the use of the experimental data on secondary particle yields from the target and muon fluxes measurements in 9 gaps of the muon filter, as well as the spectra determined from quasi-elastic events and spectra defined by extrapolating differential distributiondσ/dy in the regiony=0. The significant deviation from the linear dependence forσtot versus neutrino energy is determined in the energy range less than 15 GeV.

2 data tables

Table 1

No description provided.

Table 2

No description provided.

Investigation of exclusive channels in neutrino / anti-neutrino deuteron charged current interactions

Allasia, D. ; Angelini, C. ; van Apeldoorn, G.W. ; et al.

Nucl.Phys.B 343 (1990) 285-309, 1990.

Inspire Record 303953 DOI 10.17182/hepdata.33068

An analysis has been performed of neutrino and antineutrino interactions with protons and neutrons in a deuterium bubble chamber. The interactions under study are quasielastic neutrino-neutron scattering and one-, two- and three-pion production reactions. Results are presented on cross sections, effective mass distributions, resonance production, momentum transfer distributions and coefficients of the decay angular distributions. Where possible, comparisons are made with existing theoretical models and predictions.

10 data tables

Table 1

No description provided.

Table 2

Numerical values supplied by A.Tenner.

Table 3

Numerical values supplied by A.Tenner.

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Quasielastic Nucleon and Hyperon Production by Neutrinos and Anti-neutrinos With Energies Below 30-{GeV}

The SKAT collaboration Brunner, J. ; Grabosch, H.J. ; Kaufmann, H.H. ; et al.

Z.Phys.C 45 (1990) 551, 1990.

Inspire Record 26520 DOI 10.17182/hepdata.15281

The cross sections of neutrino and antineutrino quasielastic reactions$vn \to \mu ^ -p,\bar vp \to \mu ^ +n,\bar vp \to \mu ^ +\Lambda$ were studied in the neutrino energy range between 3 and 30 GeV. In comparison withV-A theory axial mass parameters ofMA=(1.06±0.05±0.14) GeV/c2 from neutrino andMA=(0.71±0.10±0.20) GeV/c2 from antineutrino data were found. The total cross-section for the hyperon production process can be described byMA=1.0 GeV/c2.

1 data table

Table 1

Measured Quasi-Elastic total cross section.

Final Results on $\mu e$ Pair Production in Neutrino Interactions With Chamber Skat Filled With Freon

Ammosov, V.V. ; Ermolaev, V.I. ; Ivanilov, A.A. ; et al.

Z.Phys.C 40 (1988) 493, 1988.

Inspire Record 263220 DOI 10.17182/hepdata.15559

We present the final results from the search for μe pairs produced in neutrino interactions using the freon filled bubble chamber SKAT. The rate of μ−e+ pairs to charged current events above the charm threshold is$R_{\mu ^ -e^ +}= (4.8 \pm 1.1)10^{ - 3} $. Assuming charm particle production to be the origin of the positron we calculate$R_{\Lambda _c^ +}= (6.2 \pm 3.1)10^{ - 2} $ andRD=(2.8±0.9)10−2. We observe no considerable μ−e− pair production above the background. In the regionEv>3 GeV,pμ,e>1.0 GeV/c andpμ>pe we find with a 90% confidence level the limit$R_{\mu ^ -e^ -}< 1.7 10^{ - 4} $.

3 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

Determination of the Neutral Current Chiral Coupling Constants From $U(2)_L$, $U(2)_R$, $d(2)_L$ and $d(2)_R$ From a Neutrino and Anti-neutrino Deuterium Experiment

The WA25 collaboration Allasia, D. ; Angelini, C. ; Baldini, A. ; et al.

Nucl.Phys.B 307 (1988) 1-18, 1988.

Inspire Record 260699 DOI 10.17182/hepdata.33342

The ratios of neutral-current to charged-current cross sections of v and v interactions, seperately, on proton and neutron targets have been measured. The Big European Bubble Chamber (BEBC), filled with deuterium and equipped with an external muon identifier (EMI) and an internal picket fence (IPF), was exposed to the CERN SPS (anti)neutrino wide-band beam. The measured ratios are R v p= = 0.405 ± 0.024 ± 0.021 , R v n = 0.243 ± 0.013 ± 0.016, R v p = 0.301 ± 0.027 ± 0.024 and R v n = 0.490 ± 0.050 ± 0.037 . (The first error is statistical and the second systematic). From combinations of these ratios the following neutral-current chiral coupling constants have been determined: u L 2 = 0.099 ± 0.018 ± 0.008, d L 2 = 0.202 ± 0.020 ± 0.019, u R 2 = 0.020 ± 0.016 ± 0.009 and d R 2 = 0.002 ± 0.017 ± 0.010. These results agree with the predictions of the SU(2) × U(1) standard electroweak model. Assuming ϱ = 1, the corresponding value of sin 2 θ w is found to be 0.247 ± 0.029, whereas a two-parameter fit to the data yields sin 2 θ w = 0.243 ± 0.046 and ϱ = 0.996 ± 0.041.

8 data tables

Table 1

No description provided.

Table 2

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Table 3

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