Speaker
Description
Primary cosmic rays interact with atmospheric molecules, initiating hadronic cascades in which mesons are produced. These mesons either undergo further interactions or decay into high-energy muons capable of penetrating rock and reaching deep underground detectors. Variations in atmospheric temperature influence the density of the atmosphere, thereby modulating the probability of secondary meson interactions. Specifically, an increase in temperature reduces atmospheric density, enhancing the likelihood of meson decays into muons. This results in observable seasonal variations in the muon flux detected in underground experiments. Numerous studies observed the correlation between the muon flux variations with temperature changes and extracted the corresponding correlation coefficients. Notably, the depth of overburden plays a critical role in these measurements, as it selectively shields low-energy muons whose parent mesons are less sensitive to temperature fluctuations due to their propensity to decay before interacting.
The Daya Bay Reactor Neutrino Experiment, with its three underground experimental halls at varying depths, offers an exceptional platform for investigating these effects. Leveraging a comprehensive dataset comprising over 14 billion muon events, the experiment enables precise determination of the temperature-muon flux correlation coefficients across different overburden conditions. This talk presents the current status of this analysis, utilizing the full dataset from the Daya Bay experiment to provide new insights into the relationship between atmospheric temperature, overburden, and seasonal variations in muon flux. The results contribute to a deeper understanding of cosmic ray interactions and their implications for underground particle detection.
| Collaboration you are representing | Daya Bay Reactor Neutrino Experiment |
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