0000000001287055
AUTHOR
B. García
Search for photons with energies above 1018 eV using the hybrid detector of the Pierre Auger Observatory
A search for ultra-high energy photons with energies above 1 EeV is performed using nine years of data collected by the Pierre Auger Observatory in hybrid operation mode. An unprecedented separation power between photon and hadron primaries is achieved by combining measurements of the longitudinal air-shower development with the particle content at ground measured by the fluorescence and surface detectors, respectively. Only three photon candidates at energies 1-2 EeV are found, which is compatible with the expected hadron-induced background. Upper limits on the integral flux of ultra-high energy photons of 0.027, 0.009, 0.008, 0.008 and 0.007 km-2 sr-1 yr-1 are derived at 95% C.L. for ener…
Pain and swelling in periapical surgery : a literature update
In recent years, periapical surgery (PS) has evolved thanks to the incorporation of technical and diagnostic advances. In PS, secondary effects such as pain and swelling occur as with all surgical procedures. The objective of the present study is to review the literature of articles published on pain and swelling during the postoperative period in periapical surgery. For this review, a search was made in Medline and of literature published in Spanish odontological journals. In the reviewed literature the maximum pain was produced during the first 24 postoperative hours and maximum swelling between the first and second day. Recent studies propose the use of corticoids and nonsteroidal anti-i…
Nanosecond-level time synchronization of autonomous radio detector stations for extensive air showers
To exploit the full potential of radio measurements of cosmic-ray air showers at MHz frequencies, a detector timing synchronization within 1 ns is needed. Large distributed radio detector arrays such as the Auger Engineering Radio Array (AERA) rely on timing via the Global Positioning System (GPS) for the synchronization of individual detector station clocks. Unfortunately, GPS timing is expected to have an accuracy no better than about 5 ns. In practice, in particular in AERA, the GPS clocks exhibit drifts on the order of tens of ns. We developed a technique to correct for the GPS drifts, and an independent method is used to cross-check that indeed we reach a nanosecond-scale timing accura…