110 research outputs found
A proposal to use CPLEAR as antigravitometer
The reconstructed kinematics of the isotropically emitted and their decay vertex following a annihilation at rest allows to select events with specific neutral kaon topology {\it and} energy. Thus, from the accumulated events with CPLEAR one can define high statistics subgroups of any gravitationally oriented neutral kaons with cm maximum vertical displacement, in order to search for (anti)gravity effects. The suggested new data analysis allows to combine for the first time upward moving 's with downward emitted 's, and {\it vice versa}, in order to search for any directional dependence of the parameters. The achieved limit for the relative mass difference () may be indicative of a probably unique sensitivity for the proposed antigravity search. Existing anomalous energy dependent results along with the used non-horizontal kaon beam (having in fact an equal vertical kaon displacement per as in CPLEAR) are in favour of this proposal whatever the theoretical interpretation
Tidal streams from axion miniclusters and direct axion searches
In some axion dark matter models a dominant fraction of axions resides in
dense small-scale substructures, axion miniclusters. A fraction of these
substructures is disrupted and forms tidal streams where the axion density may
still be an order of magnitude larger than the average. We discuss implications
of these streams for the direct axion searches. We estimate the fraction of
disrupted miniclusters and the parameters of the resulting streams, and find
that stream-crossing events would occur at a rate of about
for 2-3 days, during which the signal in axion detectors would be amplified by
a factor . These estimates suggest that the effect of the tidal
disruption of axion miniclusters may be important for direct axion searches and
deserves a more thorough study.Comment: Replaced with the version accepted for publication in JCA
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