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VERSION:2.0
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PRODID:UW-Madison-Physics-Events
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SEQUENCE:0
UID:UW-Physics-Event-2852
DTSTART:20130426T203000Z
DURATION:PT1H0M0S
DTSTAMP:20260412T041655Z
LAST-MODIFIED:20130418T142545Z
LOCATION:2241 Chamberlin Hall (coffee at 4:30 pm)
SUMMARY:Physics and Astrophysics from Ultrahigh Energy Cosmic Ray obse
 rvations\, Physics Department Colloquium\, Glennys Farrar\, New York U
 niversity
DESCRIPTION:Predictions for UHECR air showers using hadronic event gen
 erators tuned with LHC and lower energy accelerator data\, are in seri
 ous tension with Pierre Auger Observatory measurements\, for any assum
 ed primary composition.  It appears very difficult to get agreement wi
 th observations\, without invoking new physics above LHC energies.   S
 ome options for types of new physics which can explain the data (and o
 thers which cannot) will be discussed.  Fortunately\, as will be shown
 \, there is intrinsically enough information in hybrid events -- those
  observed with both air fluorescence and ground detectors -- to constr
 ain the new physics and composition simultaneously.  With improvements
  in separating the electromagnetic and muonic components of the ground
  signal\, it should be possible to obtain remarkably detailed diagnost
 ics about what is wrong in present hadronic event generators\, and est
 imate composition on an event-to-event basis.  Some new astrophysics r
 esults pertaining to UHECR sources and deflections in the Galactic mag
 netic field will be presented as well.
URL:https://www.physics.wisc.edu/events/?id=2852
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