Absolute total cross sections for deuteron photodisintegration between 7 and 19 MeV

Abstract

The total deuteron photodisintegration cross section has been determined in an alternative way, based on the absolute measurement of the 90' cross section and, to a lesser extent, the 0' and 180' cross sections. The accuracy of the deduced total cross sections amounts to 3%, including systematic errors. The agreement of our data with the results from recent theoretical calculations is very good.PACS number(s): 25.20. -x, 27.10.+h For a number of reasons, the study of the characteristics of the deuteron photodisintegration process has continuously attracted a lot of attention, from both the experimental and the theoretical side. More specifically, this reaction has been considered as a fundamental testing ground for the details of the nucleon-nucleon interaction. At present, the correspondence between the experimental photodisintegration data and the results from conventional theoretical approaches (including mesonexchange currents, isobaric configurations, and relativistic spin-orbit terms) seems to have reached a satisfying level. In particular, the magnitude of the total photoabsorption cross section in the low-energy region (here arbitrarily defined as the interval between the reaction threshold and, say, 25 MeV) can be extremely well described by theory. This agreement is accentuated by the high accuracy (3 -5% total uncertainty, i.e. , the sum of statistical and systematic errors) of the results from the total absorption measurements [1,2]. Such accuracy is necessary as the predictions from the various theoretical calculations are in accordance with each other within the 2%%uo level.Results from direct H(y, p) measurements [3] have a somewhat larger uncertainty (about 7%), while the data deduced from the neutron-proton radiative capture experiments [4 -9] generally show a 5 -10% total error. A balanced review of all data in the relevant energy range has been given in Refs. [2] and [8], while the general status of the theoretical as well as the experimental situation for the deuteron photodisintegration is extensively described in a recent review by Arenhovel and Sanzone [10]. However, there also exists an indirect way to determine the total photodisintegration cross section with good accuracy. This is based on an adequate knowledge of the Now at Master Foods, +d sin Ocos0+e sin 0, with 0 the c.m. proton emission angle; the so-called "Partovi coefficients" a up to e contain the information concerning the e.m. multipolarity of the involved transition(s). Consequently, one obtains (0') = a +c, do o (2) (180')=a -c, do (3) (90') =a +b +e, der (4) while the total absorption photodisintegration cross section O. T reads cr r = 4m (a + , ' b + , ', e) . --Alternately, the latter can be written as (5) cr r = 4ir -a + -( 90') -e 1 2 do, 2 3The knowledge of o. T now solely depends on the magnitude of the various terms entering the above expression; in principle, these should all be taken from experiment.In previous papers [12], we have described our results for the forward, backward, and 90' deuteron photodisintegra...

Characterization of an INVS model IV neutron counter for high precision () cross-section measurements

“…[13] calculated the 2 H(γ, n) 1 H total cross-sections with several widely-used N-N potential models, all of which were indistinguishable to within 1%, irrespective of the model used. In addition, this cross-section agrees with the world data which have uncertainties between 3 and 6% [14][15][16][17].…”

Parity-violating interaction effects in thenpsystem

“…The photo-disintegration cross sections calculated with the AV18 and BONN models from threshold to 20 MeV photon energies are in excellent agreement with data [59]- [65], see Fig. 15.…”

Electromagnetic structure of A=2 and 3 nuclei and the nuclear current operator

“…The deuteron photodisintegration cross sections up to 20 MeV photon energies obtained in impulse approximation and with the full-old and full-new ME current models are shown in Fig. 14, along with the experimental data [64][65][66][67][68][69][70]. Also shown in Fig.…”