HEPData Search

We use the reaction e+e−→μ+μ−, in the Mark J detector at the DESY high-energy e+e− collider PETRA, to test the standard electroweak theory and find good agreement. We also set limits on the parameters of several extended gauge theories.

6 data tables

Table 1

CROSS SECTION MEASUREMENT RELATIVE TO PREDICTED QED CROSS SECTION.

Table 2

FORWARD-BACKWARD ASYMMETRY. THE SYSTEMATIC ERROR IN THE ASYMMETRY IS <0.5 PCT.

Table 3

ANGULAR DISTRIBUTIONS NOT GIVEN IN PAPER. SUPPLIED BY E.DEFFUR.

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A detailed study of the proton structure functions in deep inelastic muon - proton scattering

The European Muon collaboration Aubert, J.J. ; Bassompierre, G. ; Becks, K.H. ; et al.

Nucl.Phys.B 259 (1985) 189, 1985.

Inspire Record 213461 DOI 10.17182/hepdata.13244

The x and Q 2 dependence of the single photon exchange cross section d 2 σ /d Q 2 d x and the proton structure functions F 2 ( x , Q 2 ) and R ( x , Q 2 ) have been measured in deep inelastic muon proton scattering in the region 0.02 < x < 0.8 and 3 < Q 2 < 190 GeV 2 . By comparing data at different incident muon energies R was found to have little kinematic dependence and an average value of −0.010 ± 0.037 (stat.) ± 0.102 (stat.). The observed deviations from scaling gave the value of Λ MS , the QCD mass scale parameter, to be 105 −45 +55 (stat.) −45 +85 (syst.) MeV. The fraction of the momentum of the nucleon carried by gluons was found to be ∼56% at Q 2 ∼22.5 GeV 2 . It is shown that to obtain a description of the data for F 2 ( x , Q 2 ) together with that measured in deep inelastic electron-proton scattering at lower Q 2 it is necessary to include additional higher twist contributions. The value of Λ MS remains unchanged with the inclusion of these contributions which were found to have an x -dependence of the form x 3 /(1 − x ).

285 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Measurements of Tau Lepton Production and Decay

The PLUTO collaboration Berger, Christoph ; Genzel, H. ; Lackas, W. ; et al.

Z.Phys.C 28 (1985) 1, 1985.

Inspire Record 213241 DOI 10.17182/hepdata.16019

We have studied 419 τ pair events produced in the reactione+e−→τ+ τ− at a c.m. energy of 34.6 GeV. We measure the cross section and angular distribution, as well as the decay branching ratios. The production characteristics are consistent with the Standard Electroweak Model predictions of γ andZ0 interference. The branching ratios are generally consistent with the τ decaying according to standard weak interaction principles, but we observe somewhat more decays resulting in single charged hadrons plus neutrals than are predicted by present theory.

3 data tables

Table 1

Corrected for radiative effects.

Table 2

Measured cross section relative to Standard Model Prediction.

Table 3

Asymmetry based on fits to angular distribution.

First Measurement of the Reaction $\pi^- e \to \pi^- \pi^0 e$

Amendolia, S.R. ; Arik, M. ; Badelek, B. ; et al.

Phys.Lett.B 155 (1985) 457-460, 1985.

Inspire Record 213172 DOI 10.17182/hepdata.30413

The first observation of neutral pion production in π e inelastic scattering is presented. The cross section at 300 GeV for | t ‖>62;10 −3 (GeV / c ) 2 is 2.11 ± 0.47 nb, in good agreement with the theory of PCAC anomalies with 3 quark colours.

1 data table

Table 1

No description provided.

INVESTIGATION OF INCLUSIVE PROCESSES pi- A ---> p (backwards) X AT 40-GeV/c

Albini, E. ; Antipov, V.V. ; Bellini, G. ; et al.

Sov.J.Nucl.Phys. 43 (1986) 585, 1986.

Inspire Record 215986 DOI 10.17182/hepdata.9916

None

3 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

LIMITS ON CHARM PRODUCTION IN HADRONIC INTERACTIONS NEAR THRESHOLD

Christenson, J.H. ; Hummel, E. ; Kreiter, G.A. ; et al.

Phys.Rev.Lett. 55 (1985) 154, 1985.

Inspire Record 16192 DOI 10.17182/hepdata.3274

We present the results of an experiment to search for associated charm production near threshold in 13-GeV/c π−p interactions. A large aperture PWC spectrometer was sensitive to the decay fragments of the forward-produced D*−’s expected from the two-body reactions π−+p→D*−+Λc+,Σc +,. . . . The missing baryon mass was determined from the vector momenta of the incident pion and the candidate D*−. No evidence for these reactions was found, which resulted in a 7-nb upper limit (95% confidence level) for each of the cross sections σ(π−p→D*−Λc+) and σ(π−p→D*−Σc+).

2 data tables

Table 1

Axis error includes +- 0.0/0.0 contribution (?////NOT GIVENDECAY-BR(BRN=D*(2010)- --> AD0 PI-,BR=64 IN PCT)//DECAY-BR(BRN=AD0 --> K+ PI-, BR=3 IN PCT)).

Table 2

No description provided.

Q**2 Dependence of the Proton and Neutron Structure Functions from Neutrino and anti-neutrinos Scattering in Deuterium

Allasia, D. ; Angelini, C. ; Baldini, A. ; et al.

Z.Phys.C 28 (1985) 321, 1985.

Inspire Record 213484 DOI 10.17182/hepdata.16015

12,100 νD and 10,500$\bar vD$ charged current interactions in deuterium measured in the BEBC bubble chamber were used to obtain the complete set of structure functions of proton and neutron. Thex andQ2 dependence of the structure functions of up and down valence quarks and antiquarks are presented and discussed. The Adler and Gross-Llewellyn Smith sum rules have been tested at differentQ2 values. A QCD analysis of the four non singlet structure functionsxF3νN,xuv,xdv andF2νn−F2νp has been performed yielding values ofΛLO between 100 and 300 MeV.

18 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Continuum Dimuon Production in anti-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.

1 data table

Table 1

No description provided.

Intermediate Mass Dimuon Events at the {CERN} $p \bar{p}$ Collider at $\sqrt{s}=540$-{GeV}

The UA1 collaboration Arnison, G. ; Allkofer, O.C. ; Astbury, A. ; et al.

Phys.Lett.B 155 (1985) 442-456, 1985.

Inspire Record 213203 DOI 10.17182/hepdata.49630

We report the observation of 21 dimuon events at the CERN p p Collider with the UA1 detector. The events range in invariant dimuon mass from 2 to 22 GeV / c 2 . The properties of these events are given. The bulk of the events are consistent with heavy-flavour production (mainly b b ) with a few candidates for Drell-Yan production. There remain a few events which are difficult to interpret in terms of these processes, in particular two events with isolated, like-sign muons.

2 data tables

Table 1

No description provided.

Table 2

No description provided.

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LAMBDA AND K0(S) PRODUCTION IN INELASTIC AND MULTI - NUCLEON C C INTERACTIONS AT 4.2-GeV/c PER NUCLEON

Measurement of $e^+ e^- \to \mu^+ \mu^-$: A Test of Electroweak Theories

A detailed study of the proton structure functions in deep inelastic muon - proton scattering

Measurements of Tau Lepton Production and Decay

First Measurement of the Reaction $\pi^- e \to \pi^- \pi^0 e$

INVESTIGATION OF INCLUSIVE PROCESSES pi- A ---> p (backwards) X AT 40-GeV/c

LIMITS ON CHARM PRODUCTION IN HADRONIC INTERACTIONS NEAR THRESHOLD

Q**2 Dependence of the Proton and Neutron Structure Functions from Neutrino and anti-neutrinos Scattering in Deuterium

Continuum Dimuon Production in anti-p W Collisions at 125-GeV/c

Intermediate Mass Dimuon Events at the {CERN} $p \bar{p}$ Collider at $\sqrt{s}=540$-{GeV}