Åkesson, T.
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rivet Analysis
Observation of $\Omega^-$ Production in $e^+ e^-$ Annihilation at 29-{GeV}

Klein, S. ; Himel, T. ; Abrams, G.S. ; et al.
Phys.Rev.Lett. 59 (1987) 2412, 1987.
Inspire Record 247900 DOI 10.17182/hepdata.20175

Inclusive Ω− production in e+e− annihilation at 29 GeV has been measured with the Mark II detector. From an integrated luminosity of 207 pb−1, we determine a production rate of 0.014±0.006±0.004 Ω−, Ω¯+ per hadronic event. This is roughly 35 times the Lund-model prediction of 0.0004 Ω−, Ω¯+ per hadronic event, but comparable to the Webber-model prediction of 0.006 Ω−, Ω¯+ per hadronic event. The large rate of Ω− production, compared with production rates for other baryons, and with theoretical predictions based on diquark models, indicates that spin suppression does not hold for Ω− production.

2 data tables
Table 1

Radiatively corrected inclusive cross section.

Table 2

Extrapolation to full momentum range.


Analysis of the Highest Transverse Energy Events Seen in the UA1 Detector at the S $p \bar{p}$ S Collider

The UA1 collaboration Albajar, C. ; Albrow, M.G. ; Allkofer, O.C. ; et al.
Z.Phys.C 36 (1987) 33, 1987.
Inspire Record 248074 DOI 10.17182/hepdata.15751

This is the first full solid angle analysis of large transverse energy events in\(p\bar p\) collisions at the CERN collider. Events with transverse energies in excess of 200 GeV at\(\sqrt s= 630 GeV\) are studied for any non-standard physics and quantitatively compared with expectations from perturbative QCD Monte Carlo models. A corrected differential cross section is presented. A detailed examination is made of jet profiles, event jet multiplicities and the fraction of the transverse energy carried by the two jets with the highest transverse jet energies. There is good agreement with standard theory for events with transverse energies up to the largest observed values\(( \approx \sqrt {s/2} )\) and the analysis shows no evidence for any non-QCD mechanism to account for the event characteristics.

1 data table
Table 1

No description provided.


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.


EXCLUSIVE PRODUCTION OF PROTON - ANTI-PROTON PAIRS IN TWO PHOTON COLLISIONS AT PEP

The TPC/Two Gamma collaboration Aihara, H. ; Alston-Garnjost, M. ; Avery, R.E. ; et al.
Phys.Rev.D 36 (1987) 3506, 1987.
Inspire Record 246557 DOI 10.17182/hepdata.23356

We report cross sections for the process γγ→pp¯ at center-of-mass energies W from 2.0 to 2.8 GeV. These results have been extracted from measurements of e+e−→e+e−pp¯ at an overall center-of-mass energy of 29 GeV, using the TPC/Two-Gamma facility at the SLAC storage ring PEP. Cross sections for the untagged mode [both photons nearly real] are shown to lie well above QCD predictions. Results are also presented for the single-tagged mode [one photon in the range 0.16<Q2<1.6 (GeV/c)2].

3 data tables
Table 1

Data read from graph in preprint. Statistical errors only.

Table 2

Data read from graph. Statistical errors only.

Table 3

Data read from graph. Statistical errors only.


First Observation of $\gamma \gamma \to \omega \rho^0$

The ARGUS collaboration Albrecht, H. ; Andam, A.A. ; Binder, U. ; et al.
Phys.Lett.B 196 (1987) 101, 1987.
Inspire Record 247567 DOI 10.17182/hepdata.30104

The reaction γγ → 2 π + 2 π − π 0 has been studied using the the ARGUS detector at the e + e − storage ring DORIS II at DESY. The production of the vector-meson pair ωϱ 0 is observed for the first time. The cross section for γγ → ωϱ 0 and the topological cross section for γγ → 2 π + 2 π − π 0 are given. The angular distribution in ωϱ 0 events do not indicate any specific dominant spin-parity; they are consistent with isotropic production and decay of the ω and ϱ 0 mesons over the available W γγ range.

2 data tables
Table 1

Topological cross section.

Table 2

OMEGA RHO0 Production cross section.


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.


The Holographic Bubble Chamber Experiment and the Determination of the Effective Charmed Quark Mass and the $K$ Factor for Hadronic Charm Production

Cobbaert, H. ; Hobson, P.R. ; Arnold, R. ; et al.
Z.Phys.C 36 (1987) 577, 1987.
Inspire Record 246171 DOI 10.17182/hepdata.15695

In the first holographic bubble chamber experiment — the HOBC experiment — we have accumulated a total of 40000 holograms with particle interactions. We have determined the total charm pair cross section inpN collisions to be 23.3−7.7+10 μb and 3.6−1.7+2.3 μb for 360 and 200 GeV/c incident protons respectively. We have assumed a linear dependence of the cross section on the atomic number of the target. This experiment has demonstrated the feasibility of holographic recording in small bubble chambers. Assuming that the charm cross section can be described by the standard QCD factorized expression with gluon fusion and quark-antiquark annihilation, we have used our measured charm cross sections with other measurements to determine the effective charmed quark mass to be 1.8−0.35+0.25 GeV/c2. TheK factor, which describes the importance of the higher order corrections, is calculated to be 9.8−6.9+12.5 (See noted added in proof.)

1 data table
Table 1

No description provided.


HIGH-ENERGY DIFFRACTION DISSOCIATION OF K0(L) INTO EXCLUSIVE FINAL STATES

Lamm, M.J. ; Wiss, J.E. ; Avery, P. ; et al.
Phys.Rev.D 36 (1987) 3341-3352, 1987.
Inspire Record 244943 DOI 10.17182/hepdata.23353

We have observed diffraction dissociation of KL0 mesons with a carbon target into the exclusive final states KS0π+π−, KS0ω, and KS0φ. The diffraction production cross section for these states is not strongly dependent on the incident energy, varying at most by 30% between 75 and 150 GeV. The mass distributions do not change appreciably as a function of laboratory energy. The ratio of the diffractive mass-threshold production of K*±π∓, KS0ρ, KS0ω, and KS0φ is compared with previously obtained lower-energy data.

4 data tables
Table 1

TP (=T-TMIN) distribution for K0S PI+ PI- events satisfying the diffractive cuts.

Table 2

TP distributions for K0S OMEGA and K0S PHI events which satisfy the diffractive cuts.

Table 3

CROSS SECTIONS PER NUCLEUS.

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Observation of $\Omega^*$- Production in $K^- p$ Interactions at 11-{GeV}/$c$

Aston, D. ; Awaji, N. ; Bienz, T. ; et al.
Phys.Lett.B 194 (1987) 579-585, 1987.
Inspire Record 245802 DOI 10.17182/hepdata.30108

Clear evidence is presented for the production of an Ω ∗− resonance of mass 2253±13 MeV/ c 2 and width 81±38 MeV/ c 2 in K − p interactions at 11 GeV/ c . The state is observed in the Ξ (1530)K̄ decay mode, and the corresponding inclusive cross section is estimated to be 630±180 nb. Comparisons are made with theoretical predictions and with similar states observed inhyperon beam induced data.

1 data table
Table 1

No description provided.


Study of the Reaction $\bar{p} p \to \bar{\Lambda} \Lambda$ Near Threshold

Barnes, P.D. ; Besold, R. ; Birien, P. ; et al.
Phys.Lett.B 189 (1987) 249-253, 1987.
Inspire Record 244883 DOI 10.17182/hepdata.30178

Results are presented from a study of the reaction p p→ Λ Λ near threshold. Over 3000 events recorded at s values 14.6 and 25.5 MeV above the Λ Λ threshold (2231.2 MeV) have been analysed. Results for the production cross section, differential cross section, and the Λ and Λ polarization are given at both energies and are compared with recent theoretical calculations of this process.

3 data tables
Table 1

Statistical errors only.

Table 2

No description provided.

Table 3

No description provided.