This is August's edition of the newsletter of the COST action. The aim is to keep you updated on recent and upcoming conferences and postdoc positions on subjects related to WISPs.
Cosmic Wispers preprints
When hypothetical neutrino secret interactions (νSI) are large, they form a fluid in a supernova (SN) core, flow out with sonic speed, and stream away as a fireball. For the first time, we solve all steps, systematically using relativistic hydrodynamics, although a simplified source model. The impact on SN physics and the neutrino signal is remarkably small. Even for complete thermalization within the fireball, the observable spectrum barely changes. Small energy-transfer modifications may affect the neutrino-driven explosion mechanism, but on present evidence are not ruled in or out. One potentially large effect beyond our study is quick deleptonization if νSI violate lepton number.
We return to interpreting the historical SN 1987A neutrino data from a modern perspective. We construct a suite of spherically symmetric supernova models, using four different equations of state and five choices of final baryons neutron-star (NS) mass. Our models include muons and porto-neutron star (PNS) convection. Our models generally show compatibility with the combined data of the four relevant experiments, IMB, Kam-II, BUST, and LSD, although IMB alone favors a NS mass of 1.7-1.8 solar masses, while Kam-II alone favors a mass around 1.4 solar masses. Due to PNS convection and nucleon correlations in the neutrino opacities, the predicted PNS cooling time is of 5-9 s, in conflict with late event bunches in Kam-II and BUST after 8-9 s. Speculative interpretations include the onset of fallback of transiently ejected material onto the NS, a late phase transition in the nuclear medium, or other effects adding to the standard PNS cooling emission.
The environment-dependent dilaton field is a well-motivated candidate for dark energy and naturally arises in the strong coupling limit of string theory. We present the very first experimental constraints on the parameters of this model. For this, we employ data obtained from the qBounce collaboration and the Lunar Laser Ranging (LLR) experiment. Furthermore, we forecast expected exclusion plots for the Casimir And Non Newtonian force EXperiment (Cannex) soon to be realised in an improved setup.
PhD/Postdoc/Junior Positions
Conferences