Experimental determination of the E2 component in the Coulomb dissociation of 8B

S17(0)Determined from the Coulomb Breakup of 83 MeV/Nucleon<

“…As a consequence, the reported [12] ratio of E2 and E1 S factors at E rel = 0.6 MeV should be replaced by 4.7 +2.0 −1.3 × 10 −4 . The E2 strength extracted from the inclusive breakup measurement [12] is a factor of 10 to 100 larger than the upper limits reported in other experimental studies [7,9]. However, it is only slightly smaller than or in good agreement with recent theoretical calculations of E2 strength [13,[16][17][18][19], and is consistent with the measurement of [20].…”

“…The disagreements among the direct measurements make an independent approach desirable. Peripheral transfer reactions that yield asymptotic normalization coefficients [3] and Coulomb breakup [4][5][6][7][8][9][10] permit the extraction of S factors with different systematic uncertainties. In the Coulomb breakup of 8 B, a virtual photon emitted by a heavy target nucleus such as Pb dissociates an incident 8 B projectile into 7 Be + p. This is the inverse of the radiative capture reaction.…”

“…The 8 B beam intensity was approximately 10 4 s −1 ; nearly 4 billion nuclei struck the target. A 1.5 T dipole magnet separated the breakup fragments 7 Be and p from each other and from the elastically scattered 8 B nuclei, and dispersed the fragments according to their momenta. Four multiwire drift chambers (MWDCs) were used to measure the positions and angles of the breakup fragments after they passed through the magnet.…”

“…At energies below 100 keV, our calculations show that the E2 component dominates, so these data were also excluded from the fit. A correction to the data for the feeding of the 429 keV excited state of 7 Be was made using the results of [7]. This correction is small, ranging from less than a percent at the lowest relative energies to about 10% around 2 MeV.…”

Coulomb Dissociation ofB8and the Low-Energy Cross Section of theBe7Schümann1, Hammache2, Typel3 et al. 2003Phys. Rev. Lett.Self Cite873420View full textAdd to dashboardCite

“…One possibility is Coulomb dissociation (CD) of 8 B in the electromagnetic field of a high-Z nucleus. Such measurements have been performed at low [11], intermediate [12,13], and high energies [14]. Alternatively, S 17 (0) can also be calculated from asymptotic normalization coefficients (ANC) which in turn are determined in low-energy proton-transfer or in proton-removal reactions [15,16,17].…”