Boldea, V.
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First Observation of $\gamma \gamma \to \omega \omega$

The ARGUS collaboration Albrecht, H. ; Andam, A.A. ; Binder, U. ; et al.
Phys.Lett.B 198 (1987) 577-582, 1987.
Inspire Record 247566 DOI 10.17182/hepdata.30070

The reaction γγ → 2 π + 2 π − 2 π 0 has been studied using the ARGUS detector at the e + e − storage ring DORIS II at DESY. Production of ω mesons is observed and, in particular, the reaction γγ → ωω is seen for the first time. The cross section for γγ → ωω has an enhancement at ∼ 1.9 GeV/ c 2 of about 10 nb. The cross sections for γγ → 2 π + 2 π − 2 π 0 and γγ → ωπ + π − π 0 are also given.

3 data tables
Table 1

Topological cross section. 14 pct systematic uncertainty not included.

Table 2

Cross section for (omega omega) production. Additional 25 pct systematic error not included.

Table 3

Cross section for (omega pi+ pi- pi0) where (omega omega) events have been removed. Additional 15 pct systematic error not included.


Search for Direct $\gamma$ Production at Low Transverse Momentum in 63-{GeV} $p p$ Collisions

The Axial Field Spectrometer collaboration Akesson, T. ; Albrow, M.G. ; Almehed, S. ; et al.
Phys.Rev.D 36 (1987) 2615, 1987.
Inspire Record 246577 DOI 10.17182/hepdata.23325

We have searched for direct photons of low PT (≤1.0 GeV/c) at θc.m.=90° in pp collisions at √s =63 GeV. We used two independent methods: direct detection in NaI crystals and conversion to e+e− pairs. No signal is observed; the photon spectrum is well described by the decay of hadrons. The result is consistent with a direct low-PT photon signal reported at √s =12 GeV, but excludes a rapid growth of soft-photon production with √s .

1 data table
Table 1

No description provided.


Production of W's wiith Large Transverse Momentum at the CERN Proton - Antiproton Collider

The UA1 collaboration Albajar, C. ; Albrow, M.G. ; Allkofer, O.C. ; et al.
Phys.Lett.B 193 (1987) 389-398, 1987.
Inspire Record 246169 DOI 10.17182/hepdata.30164

We have measured the W transverse momentum distribution ( p T W ) using a sample of 323 W → eν and W → μν events produced in proton-antiproton collisions at the CERN collider. In the present letter we extend the study of the distribution up to p T W ∼- m W and compare to leading and higher order QCD. This comparison is a precise test of QCD with hadron colliders and the inclusive spectrum gives good agreement over a large range of p T W . However we observed two events at very large p T W (∼- 100 GeV/ c ) in which the W candidate recoils against an energetic di-jet system. Both events have a very large missing transverse energy and a jet-jet mass compatible with the W mass. In a separate analysis, a topologically similar event has been observed in which a high-mass di-jet system is balanced by a large missing transverse energy which could be interpreted as Z 0 → ν ν decay. We cannot easily explain these three events in terms of explicit second-order QCD calculations. However we cannot exclude at this stage the possibility that they are the result of non-gaussian fluctuations in the response of UA1 calorimetry or a statistical fluctuation in the data.

1 data table
Table 1

THESE NUMBERS WRE READ OFF FIG 1A.


Measurements of the Nucleon Structure Functions F(2)N in Deep Inelastic Muon Scattering from Deuterium and Comparison with Those from Hydrogen and Iron

The European Muon collaboration Aubert, J.J. ; Bassompierre, G. ; Becks, K.H. ; et al.
Nucl.Phys.B 293 (1987) 740-786, 1987.
Inspire Record 245537 DOI 10.17182/hepdata.33529

None

12 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Pion Pair Production in Photon-photon Collisions at Dci

The DM1-DM2 collaboration Ajaltouni, Z. ; Falvard, A. ; Jousset, J. ; et al.
Phys.Lett.B 194 (1987) 573, 1987.
Inspire Record 248992 DOI 10.17182/hepdata.30109

This paper presents experimental results on π + π − production threshold from the collision of quasi-real photons. The data, obtained at the e + e − collider DCI, are a combination of the results from the DM1 and DM2 experiments. Using the e + e − and π + π − production for normalization and cross-checks, we observe a pion pair yield at low invariant mass ( W < 500 MeV/ c 2 ) which is approximately twice the one expected from Born terms.

2 data tables
Table 1

Data read from graph.

Table 2

Data read from graph.


Multiparticle Production in Proton - Nucleus Collisions at 360-{GeV}/$c$ Using the European Hybrid Spectrometer

The EHS-RCBC collaboration Bailly, J.L. ; Banerjee, S. ; Bartl, W. ; et al.
Z.Phys.C 35 (1987) 301, 1987.
Inspire Record 245414 DOI 10.17182/hepdata.15776

360 GeV/c proton interactions with aluminium (Al) and gold (Au) targets are studied using the European Hybrid Spectrometer (EHS) equipped with the Rapid Cycling Bubble Chamber (RCBC). Multiplicities, rapidity distributions and correlations between leading and other produced particles are presented and compared with Monte Carlo calculations based on the multi-chain and Lund models.

1 data table
Table 1

No description provided.


Investigation of the polarization of Lambda hyperons produced in C-12 C and C-12 Ta interactions at 4.2-GeV/c per nucleon.

Iovchev, K. ; Kladnitskaya, E.N. ; Boldea, V. ; et al.
Sov.J.Nucl.Phys. 47 (1988) 285-286, 1988.
Inspire Record 247551 DOI 10.17182/hepdata.39463

None

2 data tables
Table 1

No description provided.

Table 2

No description provided.


$D$ Meson Production From 400 GeV/$c p p$ Interactions

The LEBC-EHS collaboration Aguilar-Benitez, M. ; Allison, W.W.M. ; Bailly, J.L. ; et al.
Phys.Lett.B 189 (1987) 476, 1987.
Inspire Record 245101 DOI 10.17182/hepdata.12913

We have measured the inclusive production properties of D and D messons produced from pp interactions at s =27.4 GeV . The differential production cross section is well represented by the empirical form d 2 σ d x F d P 2 T = 1 2 [σ ( D / D )(n+1)b](1−|x F |) n exp (−bp 2 T ) with n=4.9 ± 0.5, b=(1.0±0.1)( GeV /c) −2 , and the inclusive D / D cross section σ ( D / D ) is (30.2±3.3) ωb. The QCD fusion model predicts D / D production which is in good agreement with our data except for the magnitude of the cross section which depends sensitively on the assumed mass of the charm quark.

11 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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STUDY OF THE RESONANCE PRODUCTION IN anti-n p INTERACTIONS AT 6.1-GeV/c

The Dubna-Moscow-Bucharest-Kosice-Sofiya collaboration Batyunya, B.V. ; Boguslavsky, I.V. ; Bruncko, D. ; et al.
Sov.J.Nucl.Phys. 47 (1988) 468, 1988.
Inspire Record 246882 DOI 10.17182/hepdata.9876

None

9 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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A Measurement of the Muon Pair Production in $e^+ e^-$ Annihilation at 38.3-{GeV} $\le \sqrt{s} \le$ 46.8-{GeV}

The CELLO collaboration Behrend, H.J. ; Burger, J. ; Criegee, L. ; et al.
Phys.Lett.B 191 (1987) 209-216, 1987.
Inspire Record 244835 DOI 10.17182/hepdata.30180

The e + e − → μ + μ − reaction has been studied at centre of mass energies ranging between 38.3 abd 46.8 GeV with the CELLO detector at PETRA. We present results on the cross section and the charge asymmetry for this channel. Combining all the data at the average energy 〈 s 〉=43 GeV we obtain R μμ =〈 σ μμ / σ 0 〉=0.98±0.04±0.04, 〈 A μμ 〉=(−14.1±3.7±1.0)%, where σ 0 is the QED cross section and A μμ is the charge asymmetry corrected for pure radiative effects. These results are in good agreement with the expected values of R μμ =1.01 and A μμ =−14.5% at that energy.

3 data tables
Table 1

Mu-pair cross sections.

Table 2

Corrected angular distributions with data sample divided into two energy regions with means 39 and 44 GeV and total energy region.

Table 3

Forward-backward asymmetry.