ar X iv : h ep - p h / 03 12 28 1 v 1 1 9 D ec 2 00 3 1 Physics Potential of Solar Neutrino Experiments

Recently announced results from the Sudbury Neutrino Observatory (SNO) [1] and KamLAND [2] experiments indicate that neutrino physics is moving from the discovery stage to the precision measurements stage. (For recent reviews see e. g. [3,4]). A combined analysis of the data from these experiments as well as data from other solar neutrino experiments (Super-Kamiokande [SK] [5], Chlorine [6], and Gallium [7,8,9]), place severe constraints on the neutrino parameters, especially mixing between first and second generations [10,11,12]. As an example the neutrino parameter space obtained from the global analysis of all available solar neutrino plus the KamLAND data is shown in Fig. 1 [12]. The aim of this short contribution is to reemphasize that, in principle, high-precision solarneutrino data have potential beyond exploring neutrino parameter space. Here we consider two other applications to solar physics and to nuclear physics of the neutrino-target interactions. Some time ago it was pointed out that solar neutrino data can be inverted to extract information about the density scale height [13] in a similar way the helioseismological information is inverted to obtain the sound-speed profile throughout the Sun. Even though the precision of the data has not yet reached to a point where such an inversion is possible, it is currently possible to obtain rather tight limits on fluctuations of the solar density. To do so one assumes [14] that the electron density Ne fluctuates around the value, 〈Ne〉,