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Cross Section and Tensor Analysing Power of the $\vec{d}d\to \eta\alpha$ Reaction Near Threshold

The GEM collaboration Budzanowski, A. ; Chatterjee, A. ; Gebel, R. ; et al.

Nucl.Phys.A 821 (2009) 193-209, 2009.

Inspire Record 803178 DOI 10.17182/hepdata.52401

The angular distributions of the unpolarised differential cross section and tensor analysing power $A_{xx}$ of the $\vec{d}d\to\alpha \eta$ reaction have been measured at an excess energy of 16.6 MeV. The ambiguities in the partial-wave description of these data are made explicit by using the invariant amplitude decomposition. This allows the magnitude of the s-wave amplitude to be extracted and compared with results published at lower energies. In this way, firmer bounds could be obtained on the scattering length of the $\eta \alpha$ system. The results do not, however, unambiguously prove the existence of a quasi-bound $\eta \alpha$ state.

3 data tables

Table 1

Total cross section from fit to the differential angular distribution.

Table 2

Differential angular distribution.

Table 3

Analysing power measurements.

Angular dependence of (He-3,t) charge-exchange cross sections on protons and carbon nuclei with excitation of the Delta isobar at momentum 6.91-GeV/c.

Ableev, V.G. ; Zaporozhets, S.A. ; Nomofilov, A.A. ; et al.

Sov.J.Nucl.Phys. 53 (1991) 286-291, 1991.

Inspire Record 330804 DOI 10.17182/hepdata.17254

None

8 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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MEASUREMENTS OF CROSS-SECTIONS AND CHARGE ASYMMETRIES FOR e+ e- ---> tau+ tau- AND e+ e- ---> mu+ mu- FOR S**(1/2) FROM 52-GeV TO 57-GeV

The AMY collaboration Bacala, A. ; Malchow, R.L. ; Sparks, K. ; et al.

Phys.Lett.B 218 (1989) 112-118, 1989.

Inspire Record 265797 DOI 10.17182/hepdata.51370

Measurements of the differential cross sections for e + e − →μ + μ − and e + e − →τ + τ − at values of s from 52 to 57 GeV are reported. The forward-backward asymmetries and the total cross sections for these reactions are found to be in agreement with predictions of the standard model of the electro-weak interactions. These measurements are used to extract values of the weak coupling constant g v e g v l and g A e g A l , where l = μ or τ .

11 data tables

Table 1

Axis error includes +- 5/5 contribution (Included in the quoted errors for the total cross sections. The main contribution to SYS-ERR are the systematic uncertainty in the luminosity measurement and the uncertainty in the computer modeling of the various efficiencies and backgrounds).

Table 2

Table 3

No description provided.