Cohen, Daniel H.
hep-ex
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Measurement of the Differential Cross-sections of $e^+ e^- \to \gamma \gamma$ and $e^+ e^- \to \gamma \gamma \gamma$ at $\sqrt{s}=55$-{GeV}, 56-{GeV}, 56.5-{GeV} and 57-{GeV} and Search for Unstable Photino Pair Production

The VENUS collaboration Abe, K. ; Amako, K. ; Arai, Y. ; et al.
Z.Phys.C 45 (1989) 175, 1989.
Inspire Record 280669 DOI 10.17182/hepdata.15298

Differential cross sections fore+e−→γγ have been measured at center-of-mass energies of 55, 56, 56.5 and 57 GeV. The results are in good agreement with those predicted by QED. Possible deviations from QED are studied in terms of contact interactions, and the limits on compositeness scales are obtained. Using events with a gramma pair in the final state, a search is made for the pair production of unstable photons,\(e^ +e^ -\to \tilde \gamma\tilde \gamma \). No candidate events were found and a new limit on the photino mass is obtained.

11 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

More…

rivet Analysis
Resonance Decomposition of the $D^*$0 (2420) Through a Decay Angular Analysis

The ARGUS collaboration Albrecht, H. ; Glaser, R. ; Harder, G. ; et al.
Phys.Lett.B 232 (1989) 398-404, 1989.
Inspire Record 280943 DOI 10.17182/hepdata.45198

Using data collected with the ARGUS detector, we have performed a decay angular analysis of the enhancement, previously known as the D ∗ (2420), seen in the final state D ∗ (2010) + π − . We thereby exhibit that the observed broad structure is actually due to two relatively narrow resonances, one of which is identified as the D ∗ (2459) 0 , while the massof the other is measured to be (2414±2±5) MeV/ c 2 . The results of the analysis are in good agreement with the interpretation of the two states as L =1 D mesons of spin-parities 2 + and 1 + respectively.

2 data tables
Table 1

The cross sections times branching ratio.

Table 2

It is assumed that decays D PION and D* PION saturate the total widths.


High $p_T \gamma$ and $\pi^0$ Production, Inclusive and With a Recoil Hadronic Jet, in $p p$ Collisions at $\sqrt{s}=63$-{GeV}

The Axial Field Spectrometer collaboration Akesson, T. ; Albrow, M.G. ; Almehed, S. ; et al.
Sov.J.Nucl.Phys. 51 (1990) 836-845, 1990.
Inspire Record 281284 DOI 10.17182/hepdata.48816

None

3 data tables
Table 1

Errors are combined statistical and systematic.

Table 2

Errors are combined statistical and systematic.

Table 3

Errors are combined statistical and systematic.


rivet Analysis
QUARK HADRONIZATION PROBED BY K0 MESONS

The HRS collaboration Abachi, S. ; Derrick, M. ; Kooijman, P. ; et al.
Phys.Rev.D 41 (1990) 2045, 1990.
Inspire Record 280958 DOI 10.17182/hepdata.23000

Total and differential K0 corss sections are presented from e+e− collisions at s=29 GeV in the High Resolution Spectrometer detector. K0 and charged-particle distributions are compared in a study of the hadronization of quarks of known flavor. Ecents of the reaction e+e−→cc¯ are tagged by identifying D*'s while uu¯, dd¯, or ss¯ events are tagged through the identification of a charged particle with fractional momentum near 1. Parton-shower models with cluster and string fragmentation are compared with these data. Also, certain particle scaling tests are performed using the quark-flavor tags. In addition, K0 production in two- and three-jet events is compared to these models.

6 data tables
Table 1

Corrected Cross Sections (Lund MC used to extrapolate).

Table 2

R value for K0 production.

Table 3

K0 differential cross section as function of the fractional energy.

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A MEASUREMENT OF e+ e- ---> b anti-b FORWARD - BACKWARD CHARGE ASYMMETRY BETWEEN s**(1/2) = 52-GeV AND 57-GeV

The AMY collaboration Sagawa, H. ; Lim, J. ; Abe, K. ; et al.
Phys.Rev.Lett. 63 (1989) 2341, 1989.
Inspire Record 279824 DOI 10.17182/hepdata.19996

Using 123 multihadronic inclusive muon-production e+e− annihilation events at an average c.m. energy of 55.2 GeV, we extracted the forward-backward charge asymmetry of the e+e−→bb¯ process and the R ratio for bb¯ production. We used an analysis method in which the behavior of the c quark and lighter quarks is assumed, with only that of the b quark left indeterminate. The results, Ab=-0.72±0.28(stat)±0.13(syst) and Rb=0.57±0.16±0.10, are consistent with the standard model.

2 data tables
Table 1

Asymmetry in BOTTOM quark production.

Table 2

Ratio of BOTTOM quark production to total hadron cross section (R value).


First Measurements of Hadronic Decays of the $Z$ Boson

The MARK-II collaboration Abrams, G.S. ; Adolphsen, Chris ; Aleksan, R. ; et al.
Phys.Rev.Lett. 63 (1989) 1558, 1989.
Inspire Record 282670 DOI 10.17182/hepdata.20044

We have observed hadronic final states produced in the decays of Z bosons. In order to study the parton structure of these events, we compare the distributions in sphericity, thurst, aplanarity, and number of jets to the predictions of several QCD-based models and to data from lower energies. The data and models agree within the present statistical precision.

5 data tables
Table 1

Corrected event shape distributions.

Table 2

Corrected event shape distributions.

Table 3

Corrected event shape distributions.

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Full Angular Distribution of the Analyzing Power in $\bar{p} p$ Elastic Scattering at 697-{MeV}/$c$

Bertini, R. ; Costa, M. ; Perrot, F. ; et al.
Phys.Lett.B 228 (1989) 531-535, 1989.
Inspire Record 280163 DOI 10.17182/hepdata.29779

Full angular distributions of the differential cross-section dσ/dμ and of the analysing power A y in p p elastic scattering have been measured at 697 MeV/ c . The results of A y are compared with the predictions of various theoretical models.

3 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

Legendre Polynomials from fit to angular distribution (LEG(L=0)=3.59 +- 0.02).


Analyzing Power Measurements of Coulomb Nuclear Interference With the Polarized Proton and Anti-proton Beams at 185 GeV/c

The E581/704 collaboration Akchurin, N. ; Carey, David C. ; Coleman, R. ; et al.
Phys.Lett.B 229 (1989) 299-303, 1989.
Inspire Record 280476 DOI 10.17182/hepdata.29782

The analyzing power A N of proton-proton, proton-hydrocarbon, and antiproton-hydrocarbon, scattering in the Coulomb-nuclear interference region has been measured using thhe 185 GeV/ c Fermilab polarized-proton and -antiproton beams. The results are found to be consistent with theoretical predictions within statistical uncertainties.

3 data tables
Table 1

No description provided.

Table 2

Data from hydrocarbon target.

Table 3

Data from hydrocarbon target.


Direct Photon Production at the {CERN} {ISR}

The CMOR collaboration Angelis, A.L.S. ; Basini, G. ; Besch, H.J. ; et al.
Nucl.Phys.B 327 (1989) 541-568, 1989.
Inspire Record 279988 DOI 10.17182/hepdata.33181

A measurement of direct photon production in pp collisions at a center of mass energy ∝ s =63 GeV is reported. Arrays of lead-glass calorimeters and multiwire proportional chambers were used as photon detectors. Data are presented in the transverse momentum range from 4.5 to 10 GeV/ c and compared with QCD predictions. The event structure of this sample is compared with that of a set dominated by high transverse momentum π O ́ ' s .

3 data tables
Table 1

Final Average Results from inside and outside detector.

Table 2

Results for the inside detector.

Table 3

Results for the outside detector.


rivet Analysis
Measurements of $\alpha^- s$ in $e^+ e^-$ Annihilation at $\sqrt{s}=53$.3-{GeV} and 59.5-{GeV}

The TOPAZ collaboration Adachi, I. ; Aihara, H. ; Doser, M. ; et al.
Phys.Lett.B 227 (1989) 495-500, 1989.
Inspire Record 279575 DOI 10.17182/hepdata.29800

We studied the energy-energy correlation (EEC) and its asymmetry (AEEC) using e + e − hadronic annihilation events obtained at √ s =53.3 GeV and 59.5 GeV with the TOPAZ detector at the TRISTAN collider. We used a Monte Carlo simulation combined with the QCD matrix elements by Gottschalk and Shatz and the Lund string fragmentation model. By comparing the experimental data with simulated events, we determined the strong coupling constant α s at both energies. The results are 0.129±0.007 (stat) ±0.010 (syst) at √ s =53.3 GeV and 0.122±0.008 (stat) ±0.010 (syst) at 59.5 GeV.

2 data tables
Table 1

No description provided.

Table 2

No description provided.