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D. Protić

Publications and source records attributed to D. Protić.

3 recordsLinked to original sources

Study of the $\bm{p+^6}$Li$\bm{\toη+^7}$Be reaction 11.3 MeV above threshold

The cross section for the reaction $p+^6\text{Li}\toη+^7\text{Be}$ was measured at an excess energy of 11.28 MeV above threshold by detecting the recoiling $^7$Be nuclei. A dedicated set of focal plane detectors was built for the magnetic spectrograph Big Karl and was used for identification and four momentum measurement of the $^7$Be. A differential cross section of $\frac{dσ}{dΩ}=(0.69\pm{0.20}\text{(stat.)}\pm 0.20\text{(syst.)})\text{nb/sr}$ for the ground state plus the 1/2$^-$ was measured. The result is compared to model calculations.

nucl-ex

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

The angular distributions of the unpolarised differential cross section and tensor analysing power $A_{xx}$ of the $\vec{d}d\toαη$ 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 $ηα$ system. The results do not, however, unambiguously prove the existence of a quasi-bound $ηα$ state.

nucl-ex

A precision determination of the mass of the $η$ meson

Several processes of meson production in proton-deuteron collisions have been measured simultaneously using a calibrated magnetic spectrograph. Among these processes, the $η$ meson is seen clearly as a sharp missing--mass peak on a slowly varying background in the $p+d\to ^3\textrm{He} +X$ reaction. Knowing the kinematics of the other reactions with well determined masses, it is possible to deduce a precise mass for the $η$ meson. The final result, $m(η)=547.311\pm 0.028 \textrm{(stat)} \pm 0.032 \textrm{(syst) MeV/c}^2$, is significantly lower than that found by the recent NA48 measurement, though it is consistent with values obtained in earlier counter experiments.

hep-ex