Akesson, T.
Max results
Sort by Reverse order

Showing 10 of 5437 results

Date

Test of {QED} in the Reactions $e^+ e^- \to e^+ e^-$ and $e^+ e^- \to \mu^+ \mu^-$ at {CMS} Energies From 9.4-{GeV} to 31.6-{GeV}

The PLUTO collaboration Berger, Christoph ; Genzel, H. ; Grigull, R. ; et al.
Z.Phys.C 4 (1980) 269, 1980.
Inspire Record 152289 DOI 10.17182/hepdata.15600

None

2 data tables
Table 1

No description provided.

Table 2

No description provided.


EXPERIMENTAL STUDY OF HEAVY CHARGED LEPTONS AT PETRA

Barber, D.P. ; Becker, U. ; Bei, G.D. ; et al.
Phys.Rev.Lett. 45 (1980) 1904-1907, 1980.
Inspire Record 158858 DOI 10.17182/hepdata.20675

Data from the MARK-J detector on the reactions e+e−→μ+μ−, τ+τ− in the center-of-mass energy range from 12 to 36.7 GeV are presented. The μ, τ radii are shown to be <10−16 cm. A search has been made for the production of a new heavy lepton and for the production of spin-0 supersymmetric partners of the muon. 95%-confidence-level lower limits of 16 GeV for the mass of a new charged heavy lepton and 15 GeV for the mass of the scalar partners of the muon are obtained.

1 data table
Table 1

No description provided.


EVIDENCE AGAINST THE NARROW S (1936) IN A MEASUREMENT OF ANTI-P P TOTAL CROSS-SECTION

Kamae, T. ; Aihara, H. ; Chiba, J. ; et al.
Phys.Rev.Lett. 44 (1980) 1439-1442, 1980.
Inspire Record 157934 DOI 10.17182/hepdata.20724

The total p¯p cross section has been measured in the S region by the transmission method with use of a beam-monitoring spectrometer. The result is inconsistent with the existence of the narrow resonance S(1936) with cross sections reported by previous experiments.

1 data table
Table 1

No description provided.


Observation of Upsilon, Upsilon', and Upsilon'' at the Cornell electron Storage Ring

Bohringer, T. ; Costantini, F. ; Dobbins, J. ; et al.
Phys.Rev.Lett. 44 (1980) 1111-1114, 1980.
Inspire Record 157729 DOI 10.17182/hepdata.20731

The ϒ, ϒ′, and ϒ′′ states have been observed at the Cornell Electron Storage Ring as narrow peaks in σ(e+e−→hadrons) versus beam energy. Data were collected during a run with integrated luminosity of 1000 nb−1, using the Columbia University-Stony Brook segmented NaI detector. The measured mass differences are M(ϒ′)−M(ϒ)=559±1(±3) MeV and M(ϒ′′)−M(ϒ)=889±1(±5) MeV, where the errors in parentheses represent systematic uncertainties. Preliminary values for the leptonic width ratios were also obtained.

1 data table
Table 1

HADRONIC EVENTS/SMALL-ANGLE BHABHA YIELD.


INCLUSIVE K0, LAMBDA0, K*+- (890), AND SIGMA*+- (1385) PRODUCTION IN P P COLLISIONS AT 300-GEV/C

Lopinto, F. ; Brody, A. ; Engelmann, R. ; et al.
Phys.Rev.D 22 (1980) 573-581, 1980.
Inspire Record 158990 DOI 10.17182/hepdata.24150

Inclusive K0K¯0, Λ0, and Λ¯0 cross sections have been determined using a 292-event/mb exposure of the hydrogen-filled 15-foot bubble chamber at Fermilab. From the invariant-mass distributions of V0π± pairs we find that σ(K*±(890))=4.4±1.4 mb, σ(Σ*±(1385))=0.54±0.40 mb, and σ(Σ¯*±(1385))=0.45±0.34 mb. It is estimated that 0.32 ± 0.11 of K0K¯0's, 0.21 ± 0.16 of Λ's, and 0.96 ± 0.75 of Λ¯'s originate from decays of K*(890) and Σ*(1385), respectively.

3 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.


TOTAL AND PARTIAL ANTI-P D CROSS-SECTIONS FROM 0.26-GEV/C TO 0.47-GEV/C

Kalogeropoulos, T. ; Tzanakos, G.S. ;
Phys.Rev.D 22 (1980) 2585-2594, 1980.
Inspire Record 160438 DOI 10.17182/hepdata.24164

The p¯d total cross section is ∼10% larger than the A+BP extrapolated cross section seen at higher (∼0.5-2.0 GeV/c) momenta. The excess is mainly due to the nonannihilation part of the total cross section. The p¯d annihilation cross sections in H2 and D2 are the same. These observations are consistent with known properties of the N¯N(1897). A 3σ dip is present at ∼0.43 GeV/c mainly due to pp¯ annihilation. This dip cannot be understood in terms of a single resonance at N¯N(1897) and the S(1935). Our cross sections are ∼10-20% higher than the recent measurements of Hamilton et al.

1 data table
Table 1

No description provided.


Inclusive Production of Neutral Strange Particles by 147 GeV/c $\pi^+/ K^+/ p$ Interactions in Hydrogen

Brick, D. ; Shapiro, A.M. ; Widgoff, M. ; et al.
Nucl.Phys.B 164 (1980) 1, 1980.
Inspire Record 156268 DOI 10.17182/hepdata.8251

Results are presented from a study of inclusive neutral strange particle production by a 147 GeV/ c tagged π + /K + /p beam in the Fermilab 30-inch hydrogen bubble chamber. The experiment made use of the proportional hybrid spectrometer system. Results are based on 995 K S 0 , 485 Λ, and 83 Λ found in a sample of 132 000 pictures. Cross sections are given for inclusive production of these particles by each of the three beam particles, and comparisons are made with measurements at other energies. Topological cross sections are also calculated, and KNO multiplicity scaling is investigated. Distributions are presented of invariant cross sections as functions of the Feynman scaling variable x and c.m. rapidity y . The transverse momentum-squared distributions with their fitted slopes are also given. Comparisons are made of the production characteristics for the three beam types.

3 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.


Two Particle Correlations in $e^+ e^-$ Annihilation

The PLUTO collaboration Berger, Christoph ; Genzel, H. ; Grigull, R. ; et al.
Phys.Lett.B 90 (1980) 312, 1980.
Inspire Record 144112 DOI 10.17182/hepdata.27256

We present measurements of two-particle angular correlations in hadron jets produced in e + e − annihilation between 7.7 and 31.6 GeV c.m. energy. The data are compared to predictions of high order perturbative QCD calculations.

1 data table
Table 1

No description provided.


MULTIPLICITY OF NEGATIVE PIONS PRODUCED IN CENTRAL COLLISIONS OF RELATIVISTIC NUCLEI

Bartke, J. ; Chkhaidze, L. ; Gasparian, A. ; et al.
Sov.J.Nucl.Phys. 32 (1980) 361, 1980.
Inspire Record 144581 DOI 10.17182/hepdata.17870

None

4 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

More…

Observation of Planar Three Jet Events in e+ e- Annihilation and Evidence for Gluon Bremsstrahlung

The JADE collaboration Bartel, W. ; Canzler, T. ; Cords, D. ; et al.
Phys.Lett.B 91 (1980) 142-147, 1980.
Inspire Record 143985 DOI 10.17182/hepdata.6339

Topological distributions of charged and neutral hadrons from the reaction e + e − → multihadrons are studied at √ s of about 30 GeV. An excess of planar events is observed at a rate which cannot be explained by statistical fluctuations in the standard two-jet process. The planar events, mostly consisting of a slim jet on one side and a broader jet on the other, are shown actually to possess three-jet structure by demonstrating that the broader jet itself consists of two collinear jets in its own rest system. Detailed agreement between data and predictions is obtained if the process e + e − →q q ̄ g is taken into account. This strongly suggests gluon bremsstrahlung as the origin of the planar three-jet events. By comparison of the data with the qq̄g-model we obtain a value for the strong coupling constant of α S ( q 2 = 0.17 ± 0.04.

2 data tables
Table 1

THRUST AND PLANARITY DISTRIBUTIONS. FINAL (BETTER) THRUST DISTRIBUTIONS WITH DETECTOR CORRECTIONS TO BE PUBLISHED LATER.

Table 2

No description provided.