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METHOD:PUBLISH
BEGIN:VEVENT
DTSTAMP:20260918T121009Z
LAST-MODIFIED:20141007T143529Z
DTSTART:20131113T203000Z
DTEND:20131113T213000Z
UID:event1180@bu.edu
URL:http://physics.bu.edu/internal/events/show/1180
SUMMARY:The Effect of Gravitational Focusing on Annual Modulation
DESCRIPTION:Featuring Benjamin Safdi\, Princeton University\n\nPart of the 
	HET Seminar Series.\n\nAbstract:\n\nThe scattering rate at dark-matter dire
	ct-detection experiments should\nmodulate annually due to the Earth's orbit
	 around the Sun. The rate is\ntypically thought to be extremized around Jun
	e 1\, when the relative\nvelocity of the Earth with respect to the dark-mat
	ter wind is maximal.\nI will point out that gravitational focusing can alte
	r this modulation\nphase. Unbound dark-matter particles are focused by the 
	Sun's\ngravitational potential\, affecting their phase-space density in the
	\nlab frame. Gravitational focusing can result in a significant overall\nsh
	ift in the annual-modulation phase\, which is most relevant for dark\nmatte
	r with low scattering speeds.  The induced phase shift for light\nO(10) GeV
	 dark matter may also be significant\, depending on the\nthreshold energy o
	f the experiment.  Moreover\, in the presence of\ndark-matter substructure 
	such as the dark disk\, the effect of\ngravitational focusing may be even m
	ore significant.  I will introduce\na systematic way of analyzing the effec
	ts of sub-structure using a\nharmonic-mode expansion of the scattering rate
	.
LOCATION:PRB 595\, 3 Cummington Mall\, 02215
STATUS:CONFIRMED
CLASS:PUBLIC
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