Cosmology and Accelerator Tests of Strongly Interacting Dark Matter

A natural possibility for dark matter is that it is composed of the stable pions of a QCD-like hidden sector. Existing literature largely assumes that pion self-interactions alone control the early universe cosmology. We point out that processes involving vector mesons typically dominate the physics of dark matter freeze-out and significantly widen the viable mass range for these models. The vector mesons also give rise to striking signals at accelerators. For example, in most of the cosmologically favored parameter space, the vector mesons are naturally long-lived and produce Standard Model particles in their decays. Electron and proton beam fixed-target experiments such as HPS, SeaQuest, and LDMX can exploit these signals to explore much of the viable parameter space. We also comment on dark matter decay inherent in a large class of previously considered models and explain how to ensure dark matter stability.Comment: 20 pages (4 in the Appendix), 6 figures; references adde

Characteristics of the derivation and validation groups of elderly patients diagnosed with dementia.

<p>Characteristics of the derivation and validation groups of elderly patients diagnosed with dementia.</p

Number and percentage of patients with each possible risk score and 6- and 12-month probabilities of death for each score calculated from the derivation group.

<p>Number and percentage of patients with each possible risk score and 6- and 12-month probabilities of death for each score calculated from the derivation group.</p

Predicted risk scores for mortality in elder dementia patients using Cox proportional hazard regression models in derivation group.

<p>Predicted risk scores for mortality in elder dementia patients using Cox proportional hazard regression models in derivation group.</p

Characteristics of elderly patients diagnosed with dementia and their unadjusted associations with mortality in the derivation group determined by using Cox proportional hazards regression with time-dependent covariates.

<p>Characteristics of elderly patients diagnosed with dementia and their unadjusted associations with mortality in the derivation group determined by using Cox proportional hazards regression with time-dependent covariates.</p