Date

A Study of Energy-energy Correlations Between 12-{GeV} and 46.8-{GeV} {CM} Energies

The TASSO collaboration Braunschweig, W. ; Gerhards, R. ; Kirschfink, F.J. ; et al.
Z.Phys.C 36 (1987) 349-361, 1987.
Inspire Record 248660 DOI 10.17182/hepdata.1698

We present data on energy-energy correlations (EEC) and their related asymmetry (AEEC) ine+e− annihilation in the centre of mass energy range 12<W≦46.8 GeV. The energy and angular dependence of the EEC in the central region is well described byOαs2 QCD plus a fragmentation term proportional to\({1 \mathord{\left/ {\vphantom {1 {\sqrt s }}} \right. \kern-\nulldelimiterspace} {\sqrt s }}\). BareO(α)s2 QCD reproduces our data for the large angle region of the AEEC. Nonperturbative effects for the latter are estimated with the help of fragmentation models. From various analyses using different approximations, we find that values for\(\Lambda _{\overline {MS} } \) in the range 0.1–0.3 GeV give a good description of the data. We also compare analytical calculations in QCD for the EEC in the back-to-back region to our data. The theoretical predictions describe well both the angular and energy dependence of the data in the back-to-back region.

10 data tables

Correlation function binned in cos(chi).

Correlation function binned in cos(chi).

Correlation function binned in cos(chi).

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Determination of $\alpha^- s$ From Energy-energy Correlations in $e^+ e^-$ Annihilation at 29-{GeV}

Wood, D.R. ; Petersen, A. ; Abrams, G.S. ; et al.
Phys.Rev.D 37 (1988) 3091, 1988.
Inspire Record 250899 DOI 10.17182/hepdata.23323

We have studied the energy-energy correlation in e+e− annihilation into hadrons at √s =29 GeV using the Mark II detector at the SLAC storage ring PEP. We find to O(αs2) that αs=0.158±0.003±0.008 if hadronization is described by string fragmentation. Independent fragmentation schemes give αs=0.10–0.14, and give poor agreement with the data. A leading-log shower fragmentation model is found to describe the data well.

6 data tables

Correlation data from the original PEP-5 detector.

Correlation Asymmetry data from the original PEP-5 detector.

Correlation data from the upgraded detector.

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CHARACTERISTICS OF FAST SECONDARY NEUTRONS IN p p AND p C-12 INTERACTIONS AT P = 10-GeV/c

Bekmirzaev, R.N. ; Grishin, V.G. ; Dolejsi, J. ; et al.
JINR-P1-87-443, 1987.
Inspire Record 251572 DOI 10.17182/hepdata.9496

None

3 data tables

No description provided.

No description provided.

No description provided.


HADRONS AND GAMMAS ASSOCIATED TO DIMUONS AND J / psi PARTICLES IN pi- C INTERACTIONS AT 38-GeV/c

The RISK collaboration Jani, J. ; Mihalyi, Z. ; Nyitrai, G. ; et al.
JINR-E1-87-397, 1987.
Inspire Record 251044 DOI 10.17182/hepdata.9973

None

7 data tables

No description provided.

No description provided.

No description provided.

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Jet Production and Fragmentation Properties in Deep Inelastic Muon Scattering

The European Muon collaboration Arneodo, M. ; Arvidson, A. ; Aubert, J.J. ; et al.
Z.Phys.C 36 (1987) 527, 1987.
Inspire Record 247586 DOI 10.17182/hepdata.15717

None

2 data tables

No description provided.

No description provided.


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

No description provided.


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

Radiatively corrected inclusive cross section.

Extrapolation to full momentum range.


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

Topological cross section.

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

Topological cross section. 14 pct systematic uncertainty not included.

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

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

No description provided.