Date

Search for high mass narrow resonances in virtual photon photon interactions

The TPC / TWO GAMMA collaboration Aihara, H. ; Alston-Garnjost, M. ; Avery, R.E. ; et al.
Phys.Rev.Lett. 57 (1986) 3245-3248, 1986.
Inspire Record 239032 DOI 10.17182/hepdata.20201

We report on the first search with virtual photon-photon collisions for narrow, neutral resonances with even C parity in the mass range 4.5<W<19 GeV. The data were obtained via the process e+e−→e+e−γ*γ*→e e−+R with both the scattered e+ and e− detected. We find upper limits (95% confidence level) for the partial decay width of a resonance into two photons, ranging from 50 keV at W=4.5 GeV to 10 MeV at W=19 GeV. These limits constrain theoretical models involving neutral composite bosons.

1 data table

No description provided.


$\Lambda$ Production in $e^+ e^-$ Annihilations at 29-{GeV}: A Comparison With Lund Model Predictions

Baringer, Philip S. ; Abachi, S. ; Beltrami, I. ; et al.
Phys.Rev.Lett. 56 (1986) 1346, 1986.
Inspire Record 17781 DOI 10.17182/hepdata.20257

This paper presents measurements of the inclusive production cross sections of Λ baryons in e+e− annihilations at s=29 GeV. The data sample corresponds to an integrated luminosity of 256 pb−1 collected with the High-Resolution Spectrometer at the SLAC storage ring PEP. Comparisons are made to the predictions of the Lund model. The data are well described with use of a strange-diquark suppression parameter, (usud)(sd), of 0.89 ± 0.10−0.16+0.56, and the measured Λc→Λ+X branching ratio of (23 ± 10)%.

3 data tables

No description provided.

Rapidity relative to thrust axis.

Corrected for unobserved moment regions.


Polarization of $\Lambda^\prime$s and $\bar{\Lambda}$-primes in $P P$, $\bar{P} P$, and $K^- P$ Interactions at 176-{GeV}/c

Gourlay, S.A. ; Melanson, H.L. ; Abolins, M.A. ; et al.
Phys.Rev.Lett. 56 (1986) 2244-2247, 1986.
Inspire Record 232417 DOI 10.17182/hepdata.20240

We have measured the polarization of Λ's in inclusive pp and K−p reactions and of Λ¯'s in p¯p interactions at a beam momentum of 176 GeV/c. Data were taken in the beam-fragmentation region with hyperon transverse momenta from 0.2 to 1.5 GeV/c. The P¯ produced Λ¯'s have the same magnitude and sign of polarization as the p-produced Λ's, whereas the Λ's from K−p interactions are more highly polarized and in the opposite direction.

3 data tables

No description provided.

No description provided.

No description provided.


STUDY OF THE REACTION K- P ---> K0(S) K0(S) Y* AT 40-GEV/C. (IN RUSSIAN)

Bolonkin, B.V. ; Bloshenko, S.K. ; Vladimirsky, V.V. ; et al.
Yad.Fiz. 43 (1986) 1211-1216, 1986.
Inspire Record 238226 DOI 10.17182/hepdata.17631

None

1 data table

No description provided.


Study of Hadron and Inclusive Muon Production From Electron Positron Annihilation at 39.79-{GeV} $\le \sqrt{s} \le$ 46.78-{GeV}

The Mark-J collaboration Adeva, B. ; Ansari, S. ; Becker, U. ; et al.
Phys.Rev.D 34 (1986) 681-691, 1986.
Inspire Record 230297 DOI 10.17182/hepdata.23423

We use the reaction e+e−→hadrons, in the Mark J detector at the DESY electron-positron collider PETRA, to determine the hadronic cross section up to 46.78 GeV. The production of a top quark with a charge equal to (2/3) is excluded up to 46.6 GeV with 95% C.L. The observed rise in the cross section at higher energies is consistent with the electroweak prediction for a Z0 mass of 93 GeV. We describe some unusual muon inclusive events.

3 data tables

Errors are statistical only.

Energy scan of R.

Inclusive muon cross section.


INCLUSIVE SPECTRA OF He, Li, Be, B FRAGMENTS PRODUCED ON NUCLEI BY ELECTRONS WITH ENERGIES OF 2-GeV AND 4.5-GeV AT ANGLE 0

Aivazian, G.M. ; Arutunian, V.N. ; Akhverdian, E.A. ; et al.
EFI-859-10-86-YEREVAN, 1985.
Inspire Record 223426 DOI 10.17182/hepdata.18428

None

2 data tables

FIT IN THE RANGE OF KINETIC ENERGY OF FRAGMENTS FROM 4 TO 8 MEV/NUCLEON.

FIT IN THE RANGE OF KINETIC ENERGY OF FRAGMENTS FROM 4 TO 8 MEV/NUCLEON.


Precision Test of {QED} by Direct Comparison of $e^+ e^- \to \gamma \gamma$ and $e^+ e^- \to e^+ e^-$ at 29-{GeV}

Derrick, M. ; Gan, K.K. ; Kooijman, P. ; et al.
Phys.Lett.B 166 (1986) 468-472, 1986.
Inspire Record 17510 DOI 10.17182/hepdata.30311

The ratio of differential cross sections for the reactions e + e − → γγ and e + e − → e + e − is measured at s = 29 GeV in the central polar angle region, |cos θ | < 0.55, and compared to the same ratio calculated by QED to order α 3 . The ratio of these ratios, integrated over this angular region, is 1.007±0.009±0.008, demonstrating excellent agreement between theory and experiment. The 95% confidence limits on the QED cut-off parameters for the γγ final state are Λ + > 59 GeV and Λ - > 59 GeV.

1 data table

No description provided.


A Study of Three Jet Events at the {CERN} $\bar{p} p$ Collider

The UA2 collaboration Appel, J.A. ; Bagnaia, P. ; Banner, M. ; et al.
Z.Phys.C 30 (1986) 341, 1986.
Inspire Record 219453 DOI 10.17182/hepdata.15897

The UA2 experiment, running at the CERN SPS\(\bar pp\) Collider, has performed a study of events containing three hard jets in the final state. The angular distributions of the three jets show evidence for gluon bremsstrahlung, in good agreement with a QCD model to leading order in the strong coupling constant αs. The yield of three-jet events relative to that of two-jet events provides a measure of the strong coupling constant: ;3K3/K2=0.23±0.01±0.04, whereK2 andK3 represent the contributions arising from higher order corrections in α3 to the two- and three-jet exclusive cross-sections. A detailed discussion of the systematic and theoretical uncertainties is given.

1 data table

No description provided.


New Results From Bhabha Scattering at 29-{GeV}

Derrick, M. ; Gan, K.K. ; Kooijman, P. ; et al.
Phys.Lett.B 166 (1986) 463-467, 1986.
Inspire Record 17511 DOI 10.17182/hepdata.6636

Results are reported on a high statistics study of Bhabha scattering at 29 GeV in the polar angle region, |cos θ | < 0.55. The data are consistent with the standard model, and measure vector and axial-vector coupling constants of g v 2 = 0.03 ± 0.09 and g a 2 = 0.46±0.14. Limits on the QED-cutoff parameters are Λ + > 154 GeV and Λ - > 220 GeV. Lower limits on scale parameters of composite models are in the range 0.9–2.8 TeV. The partial width of a hypothetical spin-zero boson decaying to e + e − has an upper limit which varies from 6 to 57 MeV corresponding to a boson mass in the range 45–80 GeV/ c 2 .

2 data tables

No description provided.

No description provided.


Measurement of W+- and Z0 Properties at the CERN anti-p p Collider

The UA2 collaboration Appel, J.A. ; Bagnaia, P. ; Banner, M. ; et al.
Z.Phys.C 30 (1986) 1, 1986.
Inspire Record 218462 DOI 10.17182/hepdata.2113

A study ofW± andZ0 properties has been performed using the UA2 detector at the\(\bar pp\) collider. The data correspond to a total integrated luminosity of 142 nb−1 at\(\sqrt s \)=546 GeV, and of 310 nb−1 at\(\sqrt s \)=630 GeV. The experimental results are compared with the predictions of the Standard Model of the unified electroweak theory.

3 data tables

No description provided.

No description provided.

No description provided.