Date

$\rho^0$ and $\omega$ Production in Deep Inelastic $\mu p$ Interactions at 280-{GeV}/$c$

The European Muon collaboration Arneodo, M. ; Arvidson, A. ; Aubert, J.J. ; et al.
Z.Phys.C 33 (1986) 167, 1986.
Inspire Record 231103 DOI 10.17182/hepdata.15815

Inclusive distributions of ρ0 and ω mesons have been measured in deep inelastic μ-p interactions at 280 GeV/c. A comparison of the ρ0 cross sections with other leptoproduction experiments is presented. The ω results represent the first observation of this inclusive channel in high energy leptoproduction. The ρ0 and ω yields are found to be equal as may be expected from the available density of states in isospin space. This contrasts with spin angular momentum where the vector to pseudoscalar meson ratio is suppressed relative to the available number of spin states.

4 data tables

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PRODUCTION OF BACKWARD PROTONS IN LAB SYSTEM WITH 0.2-GeV/c - 0.5-GeV/c MOMENTA IN anti-p A INTERACTIONS AT 40-GeV/c

Gabunia, L.L. ; Dzhavrishvili, A.K. ; Ivanova, A.B. ; et al.
Yad.Fiz. 46 (1987) 540-548, 1987.
Inspire Record 236228 DOI 10.17182/hepdata.39002

None

14 data tables

NUCLEUS IS C6J.

NUCLEUS IS C6J.

NUCLEUS IS C6J.

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Inclusive $\eta$ Production at Low Transverse Momentum in 63-{GeV} $p p$ Collisions at the {CERN} Intersecting Storage Rings

The Axial Field Spectrometer collaboration Akesson, T. ; Albrow, M.G. ; Almehed, S. ; et al.
Phys.Lett.B 178 (1986) 447, 1986.
Inspire Record 230636 DOI 10.17182/hepdata.30230

The inclusive production of η-mesons in pp collisions at √ s =63GeV and ϑ CM =90° has been measured for p T <1.5GeV/c. The η/π ratio decreases from its previously measured asymptotic value of η/π ∼ 0.5 at high transverse momentum, to η/π ≈0.3 at P T = 750MeV/c and η/π ≈ 0.01 at P T =300MeV/c, in a way that consistent with phase-space considerations, e.g. m T scaling. The η/π ratio, integrated from 0.2–1.5 GeV/ c , is found to be η/π=0.07±0.055.

1 data table

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Angular Distributions for High Mass Jet Pairs and a Limit on the Energy Scale of Compositeness for Quarks from the CERN p anti-p Collider

The UA1 collaboration Arnison, G. ; Albajar, C. ; Albrow, M.G. ; et al.
Phys.Lett.B 177 (1986) 244-250, 1986.
Inspire Record 230633 DOI 10.17182/hepdata.30248

Angular distributions of high-mass jet pairs (180< m 2 J <350 GeV) have been measured in the UA1 experiment at the CERN pp̄ Collider ( s =630 GeV ) . We show that angular distributions are independent of the subprocess centre-of-mass (CM) energy over this range, and use the data to put constraints on the definition of the Q 2 scale. The distribution for the very high mass jet pairs (240< m 2 J <300 GeV) has also been used to obtain a lower limit on the energy scale Λ c of compositeness of quarks. We find Λ c >415 GeV at 95% confidence level.

2 data tables

No description provided.

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A Comparison of the Particle Flow in Three Jet and Radiative Two Jet Events From $e^+ e^-$ Annihilation at $e$({CM}) = 29-{GeV}

Sheldon, P.D. ; Trilling, G. ; Petersen, A. ; et al.
Phys.Rev.Lett. 57 (1986) 1398, 1986.
Inspire Record 230941 DOI 10.17182/hepdata.20219

We have made a detailed comparison of the charged-particle flow in three-jet events (e+e−→qq¯g) and radiative two-jet events (e+e−→qq¯γ) from e+e− annihilation at Ec.m.=29 GeV. Accurate comparisons can be made because these two event types have similar topologies. In the angular region between the quark and antiquark jets, we observe substantially fewer charged tracks in the two-jet events than in the radiative three-jet events.

4 data tables

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Inclusive $\pi^0$ Production by $e^+ e^-$ Annihilation at 34.6-{GeV} Center-of-mass Energy

The TASSO collaboration Braunschweig, W. ; Gerhards, R. ; Kirschfink, F.J. ; et al.
Z.Phys.C 33 (1986) 13, 1986.
Inspire Record 230950 DOI 10.17182/hepdata.45205

The cross section for the processe+e−→π0+ anything has been measured at an average center of mass energy of 34.6 GeV for π0 energies between 0.7 and 17 GeV. The angular distribution for π0 energies larger than 2 GeV is of the formdσ/dΩ∼1+Acos2θ, withA=1.2±0.5. The ratio of π0 to π± production in the measured energy range is 2σ(π0)/(σ(π+)+σ(π−))=1.13±0.18

6 data tables

Systematic errors included.

Systematic errors included.

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Experimental Study of the Reactions $e^+ e^- \to e^+ e^-$ and $e^+ e^- \to \gamma \gamma$ at 29-{GeV}

Derrick, M. ; Gan, K.K. ; Kooijman, P. ; et al.
Phys.Rev.D 34 (1986) 3286, 1986.
Inspire Record 18585 DOI 10.17182/hepdata.23442

This paper reports measurements of the differential cross sections for the reactions e+e−→e+e− (Bhabha scattering) and e+e−→γγ (γ-pair production). The reactions are studied at a center-of-mass energy of 29 GeV and in the polar-angular region ‖costheta‖<0.55. A direct cross-section comparison between these two reactions provides a sensitive test of the predictions of quantum electrodynamics (QED) to order α3. When the ratio of γ-pair to Bhabha experimental cross sections, integrated over ‖costheta‖<0.55, is divided by the same ratio predicted from α3 QED theory, the result is 1.007±0.009±0.008. The 95%-confidence limits on the QED-cutoff parameters are Λ+>154 GeV and Λ−>220 GeV for Bhabha scattering, and Λ+>59 GeV and Λ−>59 GeV for γ-pair production.

1 data table

No description provided.


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

Errors are combined statistical and systematics.

No description provided.

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

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

Error contains both statistics and systematics.

No description provided.

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