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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.

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.

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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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.

New Results on the Reaction $e^+ e^- \to \mu^+ \mu^-$ at $\sqrt{s}=29$-{GeV}

Derrick, M. ; Fernandez, E. ; Fries, R. ; et al.

Phys.Rev.D 31 (1985) 2352, 1985.

Inspire Record 212767 DOI 10.17182/hepdata.3935

We have measured the process e+e−→μ+μ− at √s =29 GeV using the High Resolution Spectrometer at SLAC PEP. The forward-backward charge asymmetry is Aμμ=-(4.9±1.5±0.5)% based on 5057 events. A subsample of 3488 μ+μ− events in the angular range ‖cosθ‖<0.55 gives a cross-section ratio of Rμμ=0.990±0.017±0.030. The resulting couplings of the weak neutral current are gaegaμ=0.208±0.064± 0.021 and gvegvμ=0.027 ±0.051±0.089. The QED cutoff parameters are Λ+>170 GeV and Λ−>146 GeV at 95% C.L.

4 data tables

Table 1

Corrected for acceptance and O(alpha**3) QED radiation. Numerical values taken from SUGANO-ANL-HEP-CP-84-90.

Table 2

Forward-backward asymmetry based on fit to angular distribution. Result is given combined with earlier data from BENDER et al.

Table 3

No description provided.

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PROMPT MUON PRODUCTION IN e+ e- ANNIHILATIONS AT 29-GeV

The TPC/Two Gamma collaboration Aihara, H. ; Alston-Garnjost, M. ; Badtke, D.H. ; et al.

Phys.Rev.D 31 (1985) 2719, 1985.

Inspire Record 213118 DOI 10.17182/hepdata.3937

We have studied the production of prompt muons in hadronic events from e+e− annihilation at a center-of-mass energy of 29 GeV with the PEP4-TPC (Time Projection Chamber) detector. The muon p and pt distributions are well described by a combination of bottom- and charm-quark decays, with fitted semimuonic branching fractions of (15.2±1.9±1.2)% and (6.9±1.1±1.1)%, respectively. The muon spectra imply hard fragmentation functions for both b and c quarks, with 〈z(b quark)〉=0.80±0.05±0.05 and 〈z(c quark)〉=0.60±0.06±0.04. We derive neutral-current axial-vector couplings of a(b quark)=-0.9±1.1±0.3 and a(c quark)=1.5±1.5±0.5 from the forward-backward asymmetries.

5 data tables

Table 1

PT is the transverse momentum of the muon relative to the event thrust axis.

Table 2

PT is the transverse momentum of the MUON relative to the event thrust axis. At this table MUON is from JET and its PT < 1 GeV/c.

Table 3

PT is the transverse momentum of the MUON relative to the event thrust axis. At this table MUON is from JET and its PT > 1 GeV/c.

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INVESTIGATION OF THE MECHANISM OF RELATIVISTIC NUCLEUS INTERACTION FROM ANALYSIS OF C C COLLISIONS AT 4.2-GEV/C/NUCLEON. (IN RUSSIAN)

Ameev, S.Sh. ; Vinitsky, A.Kh. ; Izbasarov, M. ; et al.

Yad.Fiz. 41 (1985) 938-946, 1985.

Inspire Record 218881 DOI 10.17182/hepdata.2552

None

5 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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ANALYSIS OF THE REACTION PI- P ---> PI0 ETA N AT 40-GEV/C BEAM MOMENTUM.

The SERPUKHOV-CERN collaboration Apel, W.D. ; Augenstein, K.H. ; Bertolucci, E. ; et al.

Yad.Fiz. 41 (1985) 126-136, 1985.

Inspire Record 218766 DOI 10.17182/hepdata.2594

None

6 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Measurement of the Reaction $e^+ e^- \to \tau^+ \tau^-$ at $\sqrt{s}=29$-{GeV}

Gan, K.K. ; Beltrami, I. ; Bylsma, B.G. ; et al.

Phys.Lett.B 153 (1985) 116-120, 1985.

Inspire Record 212773 DOI 10.17182/hepdata.6571

The reaction e + e − → τ + τ − has been measured using the high resolution spectrometer at PEP. The angular distribution shows a forward-backward asymmetry of −(6.1±2.3±0.5)%, corresponding to an axial-vector coupling if g a τ g a e = 0.28 ±0.11± 0.03, in good agreement with the standard model of electroweak interactions. The measured cross section yields ifR ττ = 1.10± 0.03±0.04, consistent with QED and giving QED cutoff parameters of Λ + >92 GeV and Λ − >246 GeV at 95% C.L.

4 data tables

Table 1

Comparison of total tau pair cross section with O(alpha**3) QED prediction.

Table 2

Corrected for acceptance backgraound, and O(alpha**3) radiative effects.

Table 3

Forward-backward asymmetry based on fit to angular distributions.

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