Date

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.

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Search for Anomalous Single Photon Production at {PEP}

Bartha, G. ; Burke, D.L. ; Extermann, P. ; et al.
Phys.Rev.Lett. 56 (1986) 685, 1986.
Inspire Record 218333 DOI 10.17182/hepdata.20247

This Letter reports a search for the production by e+e− annihilation of a single photon accompanied by particles that interact only weakly in matter. The search was performed at the SLAC e+e− storage ring PEP (√s =29 GeV) with a new detector, ASP. No unexpected signal was observed. The limit Nν<14 (90% C.L.) is placed on the number of light neutrino species, and the mass of scalar electrons predicted by theories of supersymmetry is constrained to mẽ>51 GeV/c2 (90% C.L.) for mγ̃=0 and degenerate ẽ mass states.

1 data table

No description provided.


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 Meson Pair Production in $\gamma \gamma$ Interactions

Boyer, J. ; Burke, D.L. ; Butler, F. ; et al.
Phys.Rev.Lett. 56 (1986) 207, 1986.
Inspire Record 220003 DOI 10.17182/hepdata.20236

The cross section for the production of π+π− or K+K− pairs in γγ interactions is measured for mππ between 1.7 and 3.5 GeV/c2 and for two intervals of γγ center-of-mass scattering angle. Results are compared with predictions of a QCD model.

2 data tables

Data read off graph.

Data read off graph.


Upper Limits of the Proton Magnetic Form-factor in the Timelike Region From $\bar{p} p \to e^+ e^-$ at the {CERN} {ISR}

The Annecy(LAPP)-CERN-Genoa-Lyon-Oslo-Rome-Strasbourg-Turin collaboration Baglin, C. ; Baird, S. ; Bassompierre, G. ; et al.
Phys.Lett.B 163 (1985) 400-403, 1985.
Inspire Record 218159 DOI 10.17182/hepdata.49639

From the measurement of e + e - pairs from the reaction p̄p→e + e - at the CERN-ISR, using an antiproton beam and a hydrogen jet target, we derived upper limits for the proton magnetic form factor in the time-like region at Q 2 ⋍8.9( GeV c ) 2 and Q 2 ⋍12.5( GeV c ) 2 .

1 data table

No description provided.


Formation of Delta (980) and A2 (1320) in Photon-photon Collisions

The Crystal Ball collaboration Antreasyan, D. ; Aschman, D. ; Besset, D. ; et al.
Phys.Rev.D 33 (1986) 1847, 1986.
Inspire Record 217547 DOI 10.17182/hepdata.23518

The reaction γγ→π0η has been investigated with the Crystal Ball detector at the DESY storage ring DORIS II. Formation of δ(980) and A2(1320) has been observed with γγ partial widths Γγγ(A2)=1.14±0.20±0.2 6 keV and Γγγ(δ)B(δ→πη)=0.19±0.07 −0.07+0.10 keV.

2 data tables

No description provided.

No description provided.


Search for Two Photon Production of Resonances Decaying Into $K \bar{K}$ and $K \bar{K} \pi$

The TASSO collaboration Althoff, M. ; Braunschweig, W. ; Kirschfink, F.J. ; et al.
Z.Phys.C 29 (1985) 189, 1985.
Inspire Record 220941 DOI 10.17182/hepdata.16018

An analysis of the production ofKS0KS0 andK±Ks0π∓ by two quasi-real photons is presented. The cross section forγγ→K0\(\overline {K^0 } \), which is given for the γγ invariant mass range fromK\(\bar K\) threshold to 2.5 GeV, is dominated by thef′(1525) resonance and an enhancement near theK\(\bar K\) threshold. Upper limits on the product of the two-photon width times the branching ratio intoK\(\bar K\) pairs are given forΘ(1700),h(2030), and ξ(2220). For exclusive two-photon production ofK±Ks0π∓ no significant signal was observed. Upper limits are given on the cross section ofγγ→K+\(\overline {K^0 } \)π− orK−K0π+ between 1.4 and 3.2 GeV and on the product of the γγ width times the branching ratio into theK\(\bar K\)π final states for theηc(2980) and the ι(1440), yieldingΓ(γγ)→i(1440))·BR(i(1440)→K\(\bar K\)π<2.2 keV at 95% C.L.

2 data tables

Data read from graph.. Corrected for the angular distribution, which is assumed to be sin(theta)**4 for W > 1.14 GeV and isotropic in the first bin.

Data read from graph.


Evidence for Pomeron Single Quark Interactions in Proton Diffraction at the {ISR}

The R608 collaboration Smith, A.M. ; Meritet, L. ; Reyrolle, M. ; et al.
Phys.Lett.B 163 (1985) 267-272, 1985.
Inspire Record 216801 DOI 10.17182/hepdata.30332

Measurements are presented of two exclusive diffractive reactions, pp → (Λ 0 φ 0 K + ) p and pp → (Λ 0 Λ 0 p)p , at √ s = 63 GeV . Pronounced correlations with the beam direction are observed (in the rest frame of the forward-going bracketed system) for those outgoing particles which contain the beam valence quarks. In each case there is a forward-Λ 0 in correlation with a backward K + or p, respectively. No such behavior is seen for the particles which do not contain beam valence quarks (φ 0 and Λ 0 , respectively) . Interpreted as examples of pomeron-proton scattering, these results constitute evidence that, for these final states, the pomeron interacts with a single valence quark and apparently back-scatters it. The subsequent hadronization leads to a longitudinal event structure.

3 data tables

Cross sections for forward LAMBDA signal counting both arms of the p p interaction.

Cross sections for forward LAMBDA signal counting both arms of the p p interaction.

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.


EVIDENCE FOR IOTA PRODUCTION IN HIGH-ENERGY e+ e- ANNIHILATION

The JADE collaboration Bartel, W. ; Becker, L. ; Cords, D. ; et al.
DESY-85-081, 1985.
Inspire Record 220907 DOI 10.17182/hepdata.45208

None

1 data table

Background subtracted.