Seminer: 15 Temmuz 2014
“Karanlık Madde’nin Peşinde: LUX Deneyi’nden İlk Sonuçlar”
Isabel Lopes (Coimbra Üniv., Portekiz)
Tarih: 15 Temmuz 2014, Salı
Yer: İKÜ Ataköy Kampüsü Amfi B1-6
Seminer dili İngilizce’dir.
The discovery of the nature of the dark matter is presently one of the greatest challenges in physics. Direct detection of dark matter would be a scientific breakthrough of enormous proportions, with huge implications for our understanding of the universe.
One favored class of dark matter candidates, the Weakly Interacting Massive Particles (WIMPs), is expected to interact with ordinary matter.
LUX is one of the experiments that aim to detect nuclear recoils of energies of several keV resulting from the interaction of galactic WIMPs with nucleons at an expected rate lower than 1 event/kg/year. For that, it employs a double-phase (liquid/gas) xenon time projection chamber with 370 kg of mass, operated in the Davis Cavern of the Sanford Underground Laboratory (SURF), Lead, SD, USA. In this seminar, LUX experiment and its first results will be presented. From a total exposure of 85 live-days, we found no evidence of signal above expected background. The analysis of the data places the world’s most stringent limits on WIMP-nucleon spin-independent interaction cross-sections over a wide range of WIMP masses. It allowed setting a minimum upper limit on the WIMP-nucleon spin-independent elastic cross section of 7.6×10−46 cm2 at 33 GeV/c2 WIMP mass (90% C.L.), which is three times lower than any competing experiment. The improvement in the sensitivity is even more significant at low masses and challenges the interpretation of excesses as signal in other experiments.
Future plans of LUX are outlined. http://lux.brown.edu
More about LUX at BBC: http://www.bbc.com/news/science-environment-26932334