Determination of $alpha_{s}$ in second order {QCD} from hadronic $Z$ decays

The DELPHI collaboration Abreu, P. ; Adam, W. ; Adami, F. ; et al.
Z.Phys.C 54 (1992) 55-74, 1992.
Inspire Record 333272 DOI 10.17182/hepdata.14603

Distributions of event shape variables obtained from 120600 hadronicZ decays measured with the DELPHI detector are compared to the predictions of QCD based event generators. Values of the strong coupling constant αs are derived as a function of the renormalization scale from a quantitative analysis of eight hadronic distributions. The final result, αs(MZ), is based on second order perturbation theory and uses two hadronization corrections, one computed with a parton shower model and the other with a QCD matrix element model.

9 data tables

Experimental differential Thrust distributions.

Experimental differential Oblateness distributions.

Experimental differential C-parameter distributions.

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Production of the F0 Meson in the Double Pomeron Exchange Reaction $p p \to p p \pi^+ \pi^-$ at $\sqrt{s}=62$-{GeV}

The Ames-Bologna-CERN-Dortmund-Heidelberg-Warsaw collaboration Breakstone, A. ; Campanini, R. ; Crawley, H.B. ; et al.
Z.Phys.C 31 (1986) 185, 1986.
Inspire Record 227129 DOI 10.17182/hepdata.15893

Data are presented for the exclusive reaction pp → pp π+ π− at\(\sqrt s= 62GeV\) with two leading protons at large Feynman-x and a centrally produced π+;π− system. In this kinematical configuration one expects a substantial contribution from Double Pomeron Exchange, which is a potential source of glueballs. The experiment was performed at the CERN ISR using the Split Field Magnet spectrometer. In the mass range between 1,000 and 1,700 MeV/c2 the invariant mass distribution for the central π+;π− system exhibits a very significant signal for thef0(1270) and no other obvious resonant states.

1 data table

No description provided.


Observation of Two Nonleading Strangeness 1 Vector Mesons

Aston, D. ; Carnegie, R.K. ; Dunwoodie, W.M. ; et al.
Phys.Lett.B 149 (1984) 258-262, 1984.
Inspire Record 201412 DOI 10.17182/hepdata.33871

We present evidence for the existence of two strange J P = 1 − mesons; one at 1410 MeV/c 2 coupling principally to K ∗ (892)π , and the other at 1790 MeV/c 2 couplingto K π , K ∗ π and ϱ K. The data derive from a partial wave analysis of the K 0 π + π − system produced in the reaction K − p → K 0 π + π − n at 11 GeV /c . The production mechanism and quark model assignment of each state are discussed. The state at 1410 MeV/c 2 most naturally understood as the first radial excitation of the K ∗ (892), and the 1790 MeV/c 2 object can be interpreted as the triplet D wave partner to the 3 − K ∗ (1780).

1 data table

No description provided.


Resonance Production in Diffractive $\pi^- N \to K^0_s K^0_s \pi^- N^{\prime}$ at 200-GeV/c

Chen, T.Y. ; Jenkins, E.W. ; Johnson, K.J. ; et al.
Phys.Rev.D 28 (1983) 2304, 1983.
Inspire Record 182627 DOI 10.17182/hepdata.23787

The reaction π−N→KS0KS0π−N′ at 200 GeV/c has been observed with a sensitivity of 450±150 events/μb. The KS0KS0π− system exhibits substantial K*−(890)K0 production. Also produced are f0(1270)π−, f′(1515)π−, and K*−(1430)K0 final states. These resonances occur predominantly at threshold. The diffractive KS0KS0π− cross section is 3.4±1.1 μb. An enhancement near the A3−(1680) is observed in the KS0KS0π− invariant-mass distribution.

2 data tables

No description provided.

EVIDENCE FOR A3 MESON SEEN.


Dimuon Scaling Comparison at 44-{GeV} and 62-{GeV}

Antreasyan, D. ; Becker, U. ; Bellettini, G. ; et al.
Phys.Rev.Lett. 48 (1982) 302, 1982.
Inspire Record 168182 DOI 10.17182/hepdata.20610

Measurements of pp→μ+μ−+X at s=44 and 62 GeV are compared. The data are taken under identical conditions utilizing clean proton-proton collisions from the CERN intersecting storage rings and confirm scaling to 5%. The observed μ+μ− yield is a factor of 1.6±0.2 larger than estimated from a simple parton model but is consistent with QCD. The pT dependence of the muon pairs agrees well with expectations from QCD.

1 data table

No description provided.


Measurement of Dimuon Production at the {ISR}

Antreasyan, D. ; Atwood, W. ; Battiston, R. ; et al.
Phys.Rev.Lett. 45 (1980) 863, 1980.
Inspire Record 153857 DOI 10.17182/hepdata.20656

Prompt dimuon production has been measured. Events with mass up to 25 GeV/c2 are observed, as well as the J and ϒ resonances. Cross sections are given for J and ϒ production. For the continuum, the scaling function F(τ) is measured at very small values of τ=ms covering the range 0.05<τ<0.20.

3 data tables

No description provided.

HERE UPSILON = ALL USILON FAMILY. ANGULAR DISTBN. IS SEEN TO BE ISOTROPIC.

No description provided.