Et al 2000 and bugey riley et al 1999 the comparison

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Unformatted text preview: t al., 2000) Bugey (Riley et al., 1999) Measurement fission ð10À44 cm2 =fissionÞ exp =theory e CC " e CC " e CC " e CC " e NC " e NC " e NC " e NC " 1:5 Æ 0:4 1:17 Æ 0:16 1:05 Æ 0:12 0:95 Æ 0:20 3:8 Æ 0:9 2:71 Æ 0:47 3:09 Æ 0:30 3:15 Æ 0:40 0:7 Æ 0:2 1:08 Æ 0:19 0:98 Æ 0:18 0:97 Æ 0:20 0:8 Æ 0:2 0:92 Æ 0:18 0:95 Æ 0:33 1:01 Æ 0:13 2. Deuterium Direct tests of low-energy neutrino interactions on deuterium are of particular importance for both solar processes and solar oscillation probes. The Sudbury Neutrino Observatory stands as the main example, as it uses heavy water as its main target to study charged current and neutral-current interactions from the production of neutrinos from 8 B in the solar core. The Clinton P. Anderson Meson Physics Facility (LAMPF) at Los Alamos made the only direct measurement of the reaction e d ! eÀ pp using neutrinos produced from a source of stopped þ decays from stopped pions created at their 720 MeV proton beam stop (Willis et al., 1980). The cross section is averaged over the Michel muon decay spectrum. Their reported measurement of h i ¼ ð0:52 Æ 0:18Þ Â 10À40 cm2 is in good agreement with theoretical predictions. Direct cross section measurements on deuterium targets have also been carried out using antineutrinos produced in nuclear reactors. Reactor experiments, including Savannah River (Reines, Gurr, and Sobel, 1976), ROVNO (Vershinsky et al., 1991), Krasnoyarsk (Kozlov et al., 2000), and Bugey Riley et al. (1999), have reported cross sections per fission for both charged current (e d ! eþ nn) and neutral-current " " (e d ! e pn) reactions (see Table V). " Given the ever-increasing precision gained by large scale solar experiments, however, there has been greater urgency to improve upon the Æ20% accuracy on the cross section amplitude achieved by direct beam measurements. Indirect constraints on the e d cross section have therefore emerged, particularly within the context of effective field theory. As discussed in the previous section, the main uncertainty in the neutrino-deuterium cross section can be encapsulated in a single common isovector axial two-body current parameter L1;A . Constraints on L1;A come from a variety of experimental probes. There are direct extractions, such as from solar neutrino experiments and reactor measurements, as highlighted above. Constraints can also be extracted from the lifetime of tritium beta decay, muon capture on deuterium, and helio-seismology. These methods were recently summarized by Butler, Chen, and Vogel (2002) and are reproduced in Table VI. Deuterium represents one of those rare instances where the theoretical predictions are on a more solid footing than even the experimental constraints. This robustness has translated into direct improvement on the interpretation of collected neutrino data, particularly for solar oscillation phenomena. Rev. Mod. Phys., Vol. 84, N...
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