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Tests of Quantum Electrodynamics With 2, 3 and 4 Photon Final States From $e^+ e^-$ Annihilation at $\sqrt{s}=29$-{GeV}

Fernandez, E. ; Ford, William T. ; Qi, N. ; et al.
Phys.Rev.D 35 (1987) 1, 1987.
Inspire Record 230165 DOI 10.17182/hepdata.23424

High-precision measurements of electron-positron annihilation into final states of two, three, and four photons are presented. The data were obtained with the MAC detector at the PEP storage ring of the Stanford Linear Accelerator Center, at a center-of-mass energy of 29 GeV. The measured e+e−→γγ differential cross section is used to test the validity of quantum electrodynamics (QED) in this energy range; it agrees well with QED, and the limit on cutoff parameters for the electron propagator is Λ>66 GeV. The measurement of e+e−→γγγ is used to test the QED calculations of order α3 and to search for anomalies that would indicate the existence of new particles; the agreement with QED is excellent and no anomalies are found. Two events from the reaction e+e−→γγγγ are found, in agreement with the QED prediction.

3 data tables
Table 1

Errors are combined statistical and systematics.

Table 2

No description provided.

Table 3

Two 4gamma events are observed corresponding to a cross section of 0.02 PB.


SEARCH FOR SINGLE PHOTONS FROM RADIATIVE NEUTRINO OR SUPERSYMMETRIC

Ford, William T. ; Qi, N. ; Read, Alexander L. ; et al.
SLAC-PUB-4003, 1986.
Inspire Record 230016 DOI 10.17182/hepdata.23507

None

1 data table
Table 1

No description provided.


Electroweak Effects in $e^+ e^- \to e^+ e^-$ at $\sqrt{s}=29$-{GeV}

Fernandez, E. ; Ford, William T. ; Qi, N. ; et al.
Phys.Rev.D 35 (1987) 10-18, 1987.
Inspire Record 230164 DOI 10.17182/hepdata.3835

A high-precision measurement of the differential cross section for Bhabha scattering (e+e−→e+e−) is presented. The measurement was performed with the MAC detector at the PEP storage ring of the Stanford Linear Accelerator Center, at a center-of-mass energy of 29 GeV. Effects due to electroweak interference are observed and agree well with the predictions of the Glashow-Salam-Weinberg model. The agreement between the data and the electroweak prediction rules out substructure of the electron up to mass scales of 1 TeV.

5 data tables
Table 1

Error contains both statistics and systematics.

Table 2

No description provided.

Table 3

No description provided.

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A Measurement of the Sigma- Magnetic Moment Using the Sigma- ---> n e- anti-neutrino and Sigma- ---> n pi- Decay Modes

Zapalac, G. ; Hsueh, S.Y. ; Muller, D. ; et al.
Phys.Rev.Lett. 57 (1986) 1526, 1986.
Inspire Record 231107 DOI 10.17182/hepdata.42694

We have used the spin-precession technique to measure the Σ− magnetic moment (μΣ). A Σ− beam with a polarization of 22% was produced by a 400-GeV proton beam striking a Cu target at nominal production angles of ±3 mrad. We simultaneously recorded 21 000 Σ−→ne−ν¯ decays and 650 000 Σ−→nπ− decays at Σ− beam momenta of 253 and 308 GeV/c. We find μΣ=−1.166±0.014±0.010 nuclear magnetons, where the quoted errors are statistical and systematic, respectively.

1 data table
Table 1

No description provided.


STUDY OF CORRELATIONS BETWEEN RAPIDITIES OF TWO CHARGED pi MESONS IN anti-p p INTERACTIONS AT 32-GeV/c

Bumazhnov, V.A. ; Babintsev, V.V. ; Bogolyubsky, M.Yu. ; et al.
Sov.J.Nucl.Phys. 46 (1987) 289, 1987.
Inspire Record 235228 DOI 10.17182/hepdata.40835

None

2 data tables
Table 1

RAPIDITIES OF CORRELATED PIONS ARE TAKEN TO BE EQUAL.

Table 2

RAPIDITIES OF CORRELATED PIONS ARE TAKEN TO BE EQUAL.


OBSERVATION OF THE rho0 AND pi- MESONS RESONANT STATE IN THE A(3) REGION

Antipov, Yu.M. ; Batarin, V.A. ; Bezzubov, V.A. ; et al.
Sov.J.Nucl.Phys. 45 (1987) 645, 1987.
Inspire Record 233252 DOI 10.17182/hepdata.40946

None

1 data table
Table 1

COHERENT AND INCOHERENT PI- --> PI2(1680)- --> PI- MU+ MU- DISSOCIATION CROSS SECTIONS.


2.22-{GeV} $\eta \eta^\prime$ Structure Observed in 38-{GeV}/$c$ and 100-{GeV}/$c \pi^- p$ Collisions

The Serpukhov-Brussels-Los Alamos-Annecy(LAPP) collaboration Alde, D. ; Binon, F. ; Bricman, C. ; et al.
Phys.Lett.B 177 (1986) 120, 1986.
Inspire Record 230300 DOI 10.17182/hepdata.40940

A structure has been observed at 2220 MeV in the mass spectrum of ηη ′ systems produced by 38GeV/ c and 100 GeV/ c ′ negative pions on protons. The angular distribution of the decay products shows that this structure is presumably a spin J ⩾ 2 meson.

2 data tables
Table 1

No description provided.

Table 2

No description provided.


POLARIZATION ASYMMETRY OSCILLATIONS IN REACTION pi- p ---> p0 n AT t <= 3-GeV/c**2

Apokin, V.D. ; Arestov, Yu.I. ; Belikov, N.I. ; et al.
Sov.J.Nucl.Phys. 45 (1987) 840, 1987.
Inspire Record 234598 DOI 10.17182/hepdata.40905

None

1 data table
Table 1

No description provided.


MEASUREMENT OF THE INCLUSIVE BRANCHING FRACTION tau- ---> tau-neutrino pi- pi0 NEUTRAL MESON(S)

The TPC/Two Gamma collaboration Aihara, H. ; Alston-Garnjost, M. ; Avery, R.E. ; et al.
Phys.Rev.Lett. 57 (1986) 1836, 1986.
Inspire Record 233422 DOI 10.17182/hepdata.38106

We measure an inclusive branching fraction of (13.9 ± 2.0−2.2+1.9)% for the decay τ−→ντπ−π0+nh0(n>~1), where h0 is a π0 or an η. The data sample, obtained with the time-projection-chamber detector facility at the SLAC e+e− storage ring PEP, corresponds to an integrated luminosity of 72 pb−1 at 29 GeV center-of-mass energy. The measured branching fraction is somewhat greater than the theoretical prediction and, with errors taken into account, could resolve the present difference between the inclusive and the sum of the exclusive τ± branching fractions into one charged prong.

2 data tables
Table 1

No description provided.

Table 2

No description provided.


A-dependence of the Production Cross-section of $\Lambda(c$)+ Charmed Baryons in Neutron - Nucleus Interactions

The BIS-2 collaboration Aleev, A.N. ; Arefev, V.A. ; Balandin, V.P. ; et al.
Sov.J.Nucl.Phys. 46 (1987) 657, 1987.
Inspire Record 235393 DOI 10.17182/hepdata.39661

None

1 data table
Table 1

No description provided.