Date

Lepton Pair Production and Search for a New Heavy Lepton in $e^+ e^-$ Annihilation

The PLUTO collaboration Berger, Christoph ; Genzel, H. ; Grigull, R. ; et al.
Phys.Lett.B 99 (1981) 489-494, 1981.
Inspire Record 164302 DOI 10.17182/hepdata.27110

We have measured the reaction ee → μμ and ee → ττ at center of mass energies from 9.4 to 31.6 GeV. The production cross sections are in agreement with the predictions of quantum electrodynamics, resulting in cutoff parameter limits of 70–100 GeV at 95% c.l. The branching ratio for τ → μν ν has been determined as [1.78 ± 2.0 (statist.) ± 1.8(syst.)]% The existence of a new sequential heavy lepton with a mass <14.5 GeV is excluded at 95% c.l.

2 data tables

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Energy Dependence of the $P P \to \pi^+ D$ Differential Cross-section Between 500-{MeV} and 600-{MeV}

Hoftiezer, J. ; Weddigen, C. ; Favier, B. ; et al.
Phys.Lett.B 100 (1981) 462-465, 1981.
Inspire Record 170182 DOI 10.17182/hepdata.31203

The unpolarized differential cross section for the reaction pp→π + d has been measured at SIN at seven energies between 514 and 583 MeV. Data are presented in terms of a Legendre polynomial expansion. An observed strong energy dependence of the 4th order coefficient can be understood as a threshold phenomenon in a phenomenological NΔ resonant description. No evidence was found for a 1 D 2 dibaryon resonance near 600 MeV.

2 data tables

LEGENDRE POLYNOMIAL EXPANSION COEFFICIENTS DEFINED BY 4*PI*D(SIG)/DOMEGA = LEG(L=0)*P0 + LEG(L=2)*P2 + LEG(L=4)*P4. THUS, LEG(L=0) IS INTEGRATED CROSS SECTION SIG.

COEFFICIENTS OF COS(THETA)**2 EXPANSION OF 32*PI*D(SIG)/DOMEGA.


Observation of a $K \bar{K}$ Enhancement at 1.85-{GeV} in the Reaction $K^- P \to K \bar{K} \Lambda$ at 8.25-{GeV}/c

The BIRMINGHAM-CERN-GLASGOW-MICHIGAN STATE-PARIS collaboration Al- Harran, S. ; Amirzadeh, J. ; Baubillier, M. ; et al.
Phys.Lett.B 101 (1981) 357-360, 1981.
Inspire Record 170589 DOI 10.17182/hepdata.31206

In a high statistics ( ∼150 eV μb ) bubble chamber experiment on K − p interactions at 8.25 GeV c , the study of the reaction K − p → KK Λ provides evidence for an enhancement in the KK system with a mass of (1850 ± 10) MeV and a width of (80 −30 +40 ) MeV. Its possible identification with the missing isosinglet of the 3 − nonet is discussed. A K ∗ K decay mode is also observed.

1 data table

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$\Delta (\Sigma^-$l) and $\Delta$ (Sigma-t) Between 200-{MeV} and 520-{MeV}

Axen, D. ; Shypit, R. ; Comyn, M. ; et al.
J.Phys.G 7 (1981) L225-L230, 1981.
Inspire Record 171520 DOI 10.17182/hepdata.38530

New pp measurements of Delta sigma L and Delta sigma T between 200 and 520 MeV disagree with earlier Argonne data, and resolve discrepancies with inelastic data, phase-shift analysis and forward dispersion relations.

2 data tables

TOTAL CROSS SECTION DIFFERENCE FOR PURE TRANSVERSE SPIN STATES (ANTIPARALLEL MINUS PARALLEL).

TOTAL CROSS SECTION DIFFERENCE FOR PURE LONGITUDINAL SPIN STATES (ANTIPARALLEL MINUS PARALLEL).


DELTA (1236) PRODUCTION IN ANTI-NEUTRINO n ---> mu+ n pi- REACTION AT HIGH-ENERGIES

Efremenko, V.I. ; Fedotov, A.V. ; Gorichev, P.A. ; et al.
ITEP-83-1981, 1981.
Inspire Record 167553 DOI 10.17182/hepdata.40191

None

5 data tables

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Search for Narrow Resonances in $e^+ e^-$ Annihilation at $c$.m. Energies Between 33.0-{GeV} and 36.72-{GeV}

The JADE collaboration Bartel, W. ; Cords, D. ; Dittmann, P. ; et al.
Phys.Lett.B 100 (1981) 364-366, 1981.
Inspire Record 164319 DOI 10.17182/hepdata.45224

A search for narrow resonances in e + e − annihilation between 33.00 and 36.72 GeV is reported. No evidence is found for the existence of such states. The 90% confidence upper limit on the integrated resonance cross section is determined to be 28 nb MeV, a value significantly below that expected for the lowest t t bound state.

2 data tables

AVERAGE R VALUE THROUGHOUT ENERGY RANGE. SYSTEMATIC ERROR IS CONSERVATIVE AND WILL BE IMPROVED.

R VALUES AT 20 MEV STEPS. DATA TAKEN FROM TABLE IN THE PREPRINT.


SMALL MOMENTUM TRANSFER K- p CHARGE EXCHANGE SCATTERING AT 30-GeV/c

The Serpukhov-Brussels-Annecy(LAPP) collaboration Binon, F. ; Lagnaux, J.P. ; Roosen, R. ; et al.
Nuovo Cim.A 64 (1981) 89-100, 1981.
Inspire Record 164179 DOI 10.17182/hepdata.49654

The\(K^ -p \to \bar K^0 n\) charge exchange differential cross-section has been measured at 30 GeV/c with high statistical accuracy and high angular resolution. The experiment was made at the IHEP 70 GeV accelerator, by using a hodoscope hadron calorimeter to detect KL0. The cross-section shows a dip at small |t|, which indicates a dominance of spin-flip amplitudes in ρ and A2 exchanges in thet-channel.

2 data tables

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Study of Hypercharge Exchange Reactions of the Type 0- 1/2+ $\to$ 2+ 1/2+ at 4-{GeV}/$c$

The CERN-College de France-Madrid-Stockholm collaboration Aguilar-Benitez, M. ; Albajar, M.C. ; Ferrando, A. ; et al.
Z.Phys.C 8 (1981) 313, 1981.
Inspire Record 156685 DOI 10.17182/hepdata.13530

Results are presented for the quasi two-body hypercharge exchange reactions of the type 0−1/2+→2+1/2+:$$\begin{gathered}

12 data tables

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Diffractive Production of 3 $\pi$ States at 63-{GeV} and 94-{GeV}

The ACCMOR collaboration Daum, C. ; Hertzberger, L. ; Hoogland, W. ; et al.
Nucl.Phys.B 182 (1981) 269-336, 1981.
Inspire Record 156369 DOI 10.17182/hepdata.34314

Diffractive production of the 3 π system has been studied at 63 and 94 GeV using a two magnet spectrometer with high, uniform acceptance. The total number of events used in the analysis is ∼600 000. The A 2 meson is shown to be diffractively produced. The existence of a resonant component in both the 1 + and 2 − enhancements is established and resonance parameters for the corresponding A 1 and A 3 mesons are given. There are several indications in the data of states which would correspond to radial excitations in the quark model.

4 data tables

SEE C. DAUM ET AL., PL 89B, 276 (1980) (<a href=http://durpdg.dur.ac.uk/scripts/reacsearch.csh/TESTREAC/red+486> RED = 486 </a>), AND THE RECORD (<a href=http://durpdg.dur.ac.uk/scripts/reacsearch.csh/TESTREAC/red+420> RED = 420 </a>) OF THE GENEVA CONFERENCE PREPRINT, B. ALPER ET AL. (1979).

SEE C. DAUM ET AL., PL 89B, 281 (1980) (<a href=http://durpdg.dur.ac.uk/scripts/reacsearch.csh/TESTREAC/red+487> RED = 487 </a>), AND THE RECORD (<a href=http://durpdg.dur.ac.uk/scripts/reacsearch.csh/TESTREAC/red+419> RED = 419 </a>) OF THE GENEVA CONFERENCE PREPRINT, G. THOMPSON ET AL. (1979).

SEE C. DAUM ET AL., PL 89B, 285 (1980) (<a href=http://durpdg.dur.ac.uk/scripts/reacsearch.csh/TESTREAC/red+488> RED = 488 </a>), AND THE RECORD (<a href=http://durpdg.dur.ac.uk/scripts/reacsearch.csh/TESTREAC/red+421> RED = 421 </a>) OF THE GENEVA CONFERENCE PREPRINT, B. ALPER ET AL. (1979).

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Experimental Limits on the Strength of Weak Neutral Currents in Lepton Pair Production at {PETRA} Energies

The JADE collaboration Bartel, W. ; Cords, D. ; Dittmann, P. ; et al.
Phys.Lett.B 99 (1981) 281-286, 1981.
Inspire Record 156813 DOI 10.17182/hepdata.27121

The processes e + e − → e + e − and μ + μ − have been studied at PETRA using the JADE detector. The data, which were collected at s -values of up to 1300 GeV 2 have been analysed in terms of an electro-weak extension of QED to obtain values for the weak vector and axial vector couplings in the lepton sector. The values obtained agree with the predictions of the standard Salam-Weinberg model and the data are further analysed in terms of this model to obtain the limits 0.10 < sin 2 ϑ w < 0.40 (68% CL). The mass of the neutral weak gauge boson is deduced to be greater than 51 GeV/ c 2 .

3 data tables

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