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    What can we learn from three-pion interferometry ?

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    We address the question which additional information on the source shape and dynamics can be extracted from three-particle Bose-Einstein correlations. For chaotic sources the true three-particle correlation term is shown to be sensitive to the momentum dependence of the saddle point of the source and to its asymmetries around that point. For partially coherent sources the three-pion correlator allows to measure the degree of coherence without contamination from resonance decays. We derive the most general Gaussian parametrization of the two- and three-particle correlator for this case and discuss the space-time interpretation of the corresponding parameters.Comment: 16 pages, to be published in Phys. Rev.

    Chromospheric evaporation in sympathetic coronal bright points

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    {Chromospheric evaporation is a key process in solar flares that has extensively been investigated using the spectroscopic observations. However, direct soft X-ray (SXR) imaging of the process is rare, especially in remote brightenings associated with the primary flares that have recently attracted dramatic attention.} {We intend to find the evidence for chromospheric evaporation and figure out the cause of the process in sympathetic coronal bright points (CBPs), i.e., remote brightenings induced by the primary CBP.} {We utilise the high-cadence and high-resolution SXR observations of CBPs from the X-ray Telescope (XRT) aboard the Hinode spacecraft on 2009 August 23.} {We discover thermal conduction front propagating from the primary CBP, i.e., BP1, to one of the sympathetic CBPs, i.e., BP2 that is 60\arcsec away from BP1. The apparent velocity of the thermal conduction is \sim138 km s1^{-1}. Afterwards, hot plasma flowed upwards into the loop connecting BP1 and BP2 at a speed of \sim76 km s1^{-1}, a clear signature of chromospheric evaporation. Similar upflow was also observed in the loop connecting BP1 and the other sympathetic CBP, i.e., BP3 that is 80\arcsec away from BP1, though less significant than BP2. The apparent velocity of the upflow is \sim47 km s1^{-1}. The thermal conduction front propagating from BP1 to BP3 was not well identified except for the jet-like motion also originating from BP1.} {We propose that the gentle chromospheric evaporation in the sympathetic CBPs were caused by thermal conduction originating from the primary CBP.}Comment: 9 pages, 5 figure