This Week at Physics

<< August 2017 >>
Sun Mon Tue Wed Thu Fri Sat
   1   2   3   4   5 
 6   7   8   9   10   11   12 
 13   14   15   16   17   18   19 
 20   21   22   23   24   25   26 
 27   28   29   30   31   
Add an Event Edit This Event

NPAC (Nuclear/Particle/Astro/Cosmo) Forums

<< Spring 2017 Spring 2018 >>
Subscribe your calendar or receive email announcements of events

Organized by: Prof. Kimberley Palladino

Event Number 4572

  Friday, August 25th, 2017

Cosmic rays, anti-helium, and an old navy spotlight
Time: 11:00 am
Place: 5280 Chamberlin Hall
Speaker: Kfir Blum, Weizmann Institute of Sciences
Abstract: Cosmic-ray anti-deuterium and anti-helium have long been suggested as probes of dark matter, as their secondary astrophysical production was thought extremely scarce. But how does one actually predict the secondary flux? Anti-nuclei are dominantly produced in pp collisions, where laboratory cross section data is lacking. We make a new attempt at tackling this problem by appealing to a scaling law of nuclear coalescence with the physical volume of the hadronic emission region. The same volume is probed by Hanbury Brown-Twiss (HBT) two-particle correlations. We demonstrate the consistency of the scaling law with systems ranging from central and off-axis AA collisions to pA collisions, spanning 3 orders of magnitude in coalescence yield. Extending the volume scaling to the pp system, HBT data allows us to make a new estimate of coalescence, that we test against preliminary ALICE pp data. For anti-helium the resulting cross section is 1-2 orders of magnitude higher than earlier estimates. The astrophysical secondary flux of anti-helium could be within reach of a five-year exposure of AMS02.
Host: Albrecht Karle
Add this event to your calendar
©2013 Board of Regents of the University of Wisconsin System