Date

Direct Photon Production From Pions and Protons at 200-{GeV}/$c$

The NA3 collaboration Badier, J. ; Bardadin-Otwinowska, M. ; Bemporad, C. ; et al.
Z.Phys.C 31 (1986) 341, 1986.
Inspire Record 219999 DOI 10.17182/hepdata.15881

Direct photon production has been studied by an experiment performed with the NA3 spectrometer at CERN, using incident negative and positive beams at 200 GeV/c interacting with an isoscalar Carbon target. Two different triggers have been used; one of them requires the photon conversion. The experiment is sensitive to direct photons produced with 3.0≦PT≦6 GeV/c and center-of-mass rapidity −0.4≦y*≦1.2. Inclusive cross sections are given for incident π± and protons, and compared with second order QCD predictions; finally an estimation of the gluon structure function of the nucleon is given.

2 data tables

Data from conversion trigger. Statistical errors only.

Data from calorimeter trigger. Statistical errors only.


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.


Intermediate Vector Boson Properties at the {CERN} Super Proton Synchrotron Collider

The UA1 collaboration Arnison, G. ; Albrow, M.G. ; Allkofer, O.C. ; et al.
EPL 1 (1986) 327-345, 1986.
Inspire Record 219230 DOI 10.17182/hepdata.30283

The properties of a sample of 172 charged intermediate vector bosons decaying in the (eνe) channel and 16 neutral intermediate vector bosons decaying in the (e+e-) channel are described. Masses, decay widths, decay angular distributions, and production cross-sections are given; they are shown to be in excellent agreement with the expectations of the SU2 ⊗ U1 standard model. A limit is put on the number of light-neutrino types Nν ≤ 10 at 90% c.l.

2 data tables

W CROSS SECTIONS ARE GIVEN IN ARNISON ET AL., NC 44A, 1.

No description provided.


Evidence for Structure in the 1.7-{GeV} Mass Region of the $K^+ K^-$ Final State Centrally Produced in the Reactions $\pi^+ p \to \pi^+ (K^+ K^-$) $p$ and $p p \to p (K^+ K^-$) $p$ at 85-{GeV}/$c$

The Athens-Bari-Birmingham-CERN collaboration Armstrong, T.A. ; Bloodworth, I.J. ; Carney, J.N. ; et al.
Phys.Lett.B 167 (1986) 133-137, 1986.
Inspire Record 219229 DOI 10.17182/hepdata.30285

The reactions π + p → π + (K + K − )p and pp → p(K + K − )p where the K + K − system is centrally produced have been studied at 85 GeV/ c . The K + K − spectrum contains several structures in the regions of S ∗ ø , f A 2 and f′. Structure is observed in the 1.7 GeV mass region which cannot be attributed to the g meson. The most likely interpretation of the data is that we observe the θ with a mass of 1.742 GeV and a new resonance at a mass of 1.629±0.010 GeV with a width of 0.082±0.030 GeV.

1 data table

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.


Composition of Particles Emitted at Large $p_T$ and Medium Angles in $p p$, $d d$, and $\alpha \alpha$ Collisions at the {CERN} Intersecting Storage Rings

The Ames-Bologna-CERN-Dortmund-Heidelberg-LBL-Lund-Warsaw collaboration Breakstone, A. ; Claesson, G. ; Crawley, H.B. ; et al.
Z.Phys.C 30 (1986) 507, 1986.
Inspire Record 218607 DOI 10.17182/hepdata.15905

The relative yields of kaons and protons compared with the yield of pions at highpT and polar angles θ away from 90° (in the range from 10° to 45°) are presented forpp, dd, and αα interactions at a centre-of-mass energy\(\sqrt {s_{NN} }= 31\) GeV per nucleon-nucleon collision. The measured particle ratios depend on the atomic mass numberA of the beam particles and on θ. TheA dependence of the ratios becomes stronger for largerpT and is more pronounced at smaller polar angles.

4 data tables

ERRORS ARE PURELY STATISTICAL.

ERRORS ARE PURELY STATISTICAL.

ERRORS ARE PURELY STATISTICAL.

More…

A STUDY OF eta FORMATION IN PHOTON-PHOTON COLLISIONS AT PEP

The TPC/Two Gamma collaboration Aihara, H. ; Alston-Garnjost, M. ; Armitage, J.C. ; et al.
Phys.Rev.D 33 (1986) 844, 1986.
Inspire Record 217503 DOI 10.17182/hepdata.23508

The two-photon production of the η meson has been observed, and a value has been determined for the two-photon η decay width by a measurement of the cross section σ(e+e−→e+e−η) where η→γγ. The measurement was made with the TPC/Two-Gamma facility at the SLAC e+e− collider PEP, with an accumulated data sample of 64.5 pb−1. The η→γγ events were both triggered and detected by the pole-tip calorimeter. The measured two-photon η decay width is Γη→γγ=0.64±0.14 (statistical) ±0.13 (systematic) keV, in agreement with earlier similarly determined values.

1 data table

No description provided.


CHARGED D* MESON PRODUCTION IN e+ e- ANNIHILATION AT S**(1/2) = 29-GeV

The TPC/Two Gamma collaboration Aihara, H. ; Alston-Garnjost, M. ; Armitage, J.C. ; et al.
Phys.Rev.D 34 (1986) 1945, 1986.
Inspire Record 217416 DOI 10.17182/hepdata.23509

The production of charmed D* mesons in e+e− annihilations at a center-of-mass energy of 29 GeV has been studied using the time-projection-chamber (TPC) detector at the SLAC storage ring PEP. The production cross section, fragmentation function, and forward-backward asymmetry due to electroweak effects are measured, and a limit on D0-D¯0 mixing is determined.

2 data tables

No description provided.

No description provided.


Direct Photon Pair Production From Pions and Protons at 200-{GeV}/$c$

The NA3 collaboration Badier, J. ; Bardadin-Otwinowska, M. ; Bemporad, C. ; et al.
Phys.Lett.B 164 (1985) 184-188, 1985.
Inspire Record 217947 DOI 10.17182/hepdata.30329

We present results from a direct photon pair search performed with the NA3 spectrometer, using incident positive and negative beams at 200 GeV/ c interacting with a carbon target. The experiment is sensitive to photons with p T >1.8 GeV / c and −0.4⩽y ∗ ⩽1.0 , one in each arm of the apparatus. A 3 standard deviation signal is seen in τ − and p interactions. The cross section is higher than the second order QCD calculations, but systematic errors are large.

1 data table

No description provided.


Study of the Reaction $\gamma \gamma \to 2 \pi^+ 2 \pi^- \pi^0$ and Upper Limits on the Production of $\gamma \gamma \to \omega \omega$ and $\gamma \gamma \to \rho^0 \omega$

The PLUTO collaboration Berger, Christoph ; Genzel, H. ; Lackas, W. ; et al.
Z.Phys.C 29 (1985) 183, 1985.
Inspire Record 220911 DOI 10.17182/hepdata.15911

A search for the reactionsγγ→ωω andγγ→ρ0ω has been carried out at an averagee+e− CM energy of 34.6 GeV with an integrated luminosity of 45 pb−1. Upper limits are set for these two channels over the γγ CM Energy range of 1.6 to 2.5 GeV. The cross section is determined for the exclusive channelγγ→π+2π−π0.

3 data tables

Data read from graph.

Data read from graph.

Data read from graph.