First Science Results from the LUX Dark Matter Experiment Daniel McKinsey, LUX Co-Spokesperson, Yale University Richard Gaitskell, LUX Co-Spokesperson, Brown University on behalf of the LUX Collaboration http://luxdarkmatter.org Sanford Underground Research Facility OctoberS 30, 2013 LUX Dark Matter Experiment / Sanford Lab Rick Gaitskell (Brown) / Dan McKinsey (Yale) 1 Composition of the Universe The Higgs particle has been discovered, the last piece of the Standard Model. But as successful as it has been, the Standard Model describes only 5% of the universe. The remaining 95% is in the form of dark energy and dark matter, whose fundamental nature is almost completely unknown. Image: X-ray: NASA/CXC/CfA/M.Markevitch et al.; www.quantumdiaries.org Optical: NASA/STScI; Magellan/U.Arizona/D.Clowe et al.; Lensing Map: NASA/STScI; ESO WFI; Magellan/U.Arizona/D.Clowe et al. LUX Dark Matter Experiment / Sanford Lab 2 Rick Gaitskell (Brown) / Dan McKinsey (Yale) 2 Evidence for Dark Matter Galaxy rotation curves The cosmic microwave background www.quantumdiaries.org Image: ESA and the Planck collaboration Gravitational lensing • 27% of the energy composition of the universe • Properties: • Stable and electrically neutral • Non-baryonic • Non-relativistic • Estimated local density: 0.3±0.1GeV·cm-3 • Candidates: WIMPs, axions, dark photons,... Colley, Turner, Tyson, and NASA LUX Dark Matter Experiment / Sanford Lab 3 Rick Gaitskell (Brown) / Dan McKinsey (Yale) 3 Weakly Interacting Massive Particles (WIMPs) A new particle that only very weakly interacts with ordinary matter could form Cold Dark Matter - Formed in massive amounts in the Big Bang. - Non-relativistic freeze-out. Decouples from ordinary matter. - Would exist today at densities of about 1000/m3. Supersymmetry provides a natural candidate – the neutralino. - Lowest mass superposition of photino, zino, higgsino - Mass range from the proton mass to thousands of times the proton mass. - Wide range of cross-sections with ordinary matter, from 10-40 to 10-50 cm2. - Charge neutral and stable! Universal Extra Dimensions: predicts stable Kaluza-Klein (KK) particles - Similar direct detection properties as neutralino - Distinguishable from neutralinos at accelerators LUX Dark Matter Experiment / Sanford Lab 4 Rick Gaitskell (Brown) / Dan McKinsey (Yale) 4 WIMP Direct Detection Look for anomalous nuclear recoils in a low-background detector. R = N ρ σ <v>. From <v> = 220 km/s, get order of 10 keV deposited. Requirements: •Low radioactivity •Low energy threshold •Gamma ray rejection •Scalability •Deep underground laboratory LUX Dark Matter Experiment / Sanford Lab 5 Rick Gaitskell (Brown) / Dan McKinsey (Yale) 5 Current WIMP Cross-section Limits SuperCDMS Soudan CDMS-lite SuperCDMS Soudan Low Threshold XENON 10 S2 (2013) 10!39 CDMS-II Ge Low Threshold (2011) 10!3 CoGeNT PICO250-C3F8 !40 (2012) !4 10 CDMS Si 10 (2013) # ! ! 41 5 # 2 10 DAMA SIMPLE (2012) 10 COUPP (2012) pb cm ! ! !42 CRESST !6 10 ZEPLIN-III (2012) 10 SuperCDMS !43 CDMS II Ge (2009) !7 10 EDELWEISS (2011) 10 SNOLAB SuperCDMS Soudan section section N EU TR Xenon100 (2012) !44 IN DarkSide 50 !8 10 O 10 7Be C TT LUX OHE SCA ER cross cross R NT I Neutrinos E 8 N !45 B G PICO250-CF3I !9 10 Neutrinos 10 Xenon1T !46 DEAP3600 !10 10 DarkSide G2 10 LZ nucleon nucleon ! ! !47 !11 10 (Green&ovals)&Asymmetric&DM&& 10 (Violet&oval)&Magne7c&DM& RING ATTE !48 (Blue&oval)&Extra&dimensions&& NT SC !12 E WIMP HER WIMP 10 10 (Red&circle)&SUSY&MSSM& CO RINO &&&&&MSSM:&Pure&Higgsino&& NEUT !49 !13 10 &&&&&MSSM:&A&funnel& Atmospheric and DSNB Neutrinos 10 &&&&&MSSM:&BinoEstop&coannihila7on& !50 &&&&&MSSM:&BinoEsquark&coannihila7on& !14 10 & 10 1 10 100 1000 104 WIMP Mass GeV c2 LUX Dark Matter Experiment / Sanford Lab 6 Rick Gaitskell (Brown) / Dan McKinsey (Yale) 6 ! " # Two-phase Xenon WIMP Detectors Z position from S1 – S2 timing X-Y positions from S2 light pattern Excellent 3D imaging (~mm resolution) - eliminates edge events - rejects multiple scatters Gamma ray, neutron backgrounds reduced by self-shielding Reject gammas, betas by charge (S2) to light (S1) ratio. Expect > 99.5% rejection. LUX Dark Matter Experiment / Sanford Lab 7 Rick Gaitskell (Brown) / Dan McKinsey (Yale) 7 The LUX Detector Thermosyphon Copper shield Water tank Top PMT array Anode grid PTFE reflector panels and field cage Low-radioactivity Titanium Cryostat Cathode grid 370 kg total xenon mass 250 kg active liquid xenon Bottom PMT array 118 kg fiducial mass LUX Dark Matter Experiment / Sanford Lab 8 Rick Gaitskell (Brown) / Dan McKinsey (Yale) 8 LUX Benefits from an Exceptional Lab and Exceptional Lab Support LUX Dark Matter Experiment / Sanford Lab Rick Gaitskell (Brown) / Dan McKinsey (Yale) 9 The LUX Collaboration: ~100 researchers from 17 institutions Collaboration Meeting, Brown Sanford Lab, April 2013 SD School of Mines Richard Gaitskell PI, Professor Simon Fiorucci Research Associate Xinhua Bai PI, Professor Monica Pangilinan Postdoc Tyler Liebsch Graduate Student Jeremy Chapman Graduate Student Doug Tiedt Graduate Student David Malling Graduate Student James Verbus Graduate Student Samuel Chung Chan Graduate Student SDSTA Dongqing Huang Graduate Student David Taylor Project Engineer Mark Hanhardt Support Scientist Case Western Thomas Shutt PI, Professor Texas A&M Dan Akerib PI, Professor Karen Gibson Postdoc James White † PI, Professor Tomasz Biesiadzinski Postdoc Robert Webb PI, Professor Wing H To Postdoc Rachel Mannino Graduate Student Adam Bradley Graduate Student Clement Sofka Graduate Student Patrick Phelps Graduate Student Chang Lee Graduate Student UC Davis Kati Pech Graduate Student Mani Tripathi PI, Professor Imperial College London Bob Svoboda Professor Richard Lander Professor Henrique Araujo PI, Reader Britt Holbrook Senior Engineer Tim Sumner Professor John Thomson Senior Machinist Alastair Currie Postdoc Ray Gerhard Electronics Engineer Adam Bailey Graduate Student Aaron Manalaysay Postdoc Matthew Szydagis Postdoc Lawrence Berkeley + UC Berkeley Richard Ott Postdoc Bob Jacobsen PI, Professor Jeremy Mock Graduate Student Murdock Gilchriese Senior Scientist James Morad Graduate Student University of Edinburgh University of South Dakota Kevin Lesko Senior Scientist Nick Walsh Graduate Student Dongming Mei PI, Professor Carlos Hernandez Faham Postdoc Michael Woods Graduate Student Alex Murphy PI, Reader Chao Zhang Postdoc Victor Gehman Scientist Sergey Uvarov Graduate Student Paolo Beltrame Research Fellow Angela Chiller Graduate Student Mia Ihm Graduate Student Brian Lenardo Graduate Student James Dobson Postdoc Chris Chiller Graduate Student Dana Byram *Now at SDSTA Lawrence Livermore University of Maryland UC Santa Barbara Adam Bernstein PI, Leader of Adv. Detectors Group Carter Hall PI, Professor Harry Nelson PI, Professor Yale Dennis Carr Mechanical Technician Attila Dobi Graduate Student Mike Witherell Professor Kareem Kazkaz Staff Physicist Richard Knoche Graduate Student Daniel McKinsey PI, Professor Dean White Engineer Peter Sorensen Staff Physicist Jon Balajthy Graduate Student Peter Parker Professor Susanne Kyre Engineer John Bower Engineer Sidney Cahn Lecturer/Research Scientist Carmen Carmona Postdoc Ethan Bernard Postdoc Curt Nehrkorn Graduate Student University of Rochester Markus Horn Postdoc LIP Coimbra Scott Haselschwardt Graduate Student Blair Edwards Postdoc Frank Wolfs PI, Professor Isabel Lopes PI, Professor Scott Hertel Postdoc University College London Wojtek Skutski Senior Scientist Jose Pinto da Cunha Assistant Professor Kevin O’Sullivan Postdoc Eryk Druszkiewicz Graduate Student Vladimir Solovov Senior Researcher Nicole Larsen Graduate Student Chamkaur Ghag PI, Lecturer Mongkol Moongweluwan Graduate Student Luiz de Viveiros Postdoc Evan Pease Graduate Student Lea Reichhart Postdoc Alexander Lindote Postdoc Brian Tennyson Graduate Student Francisco Neves Postdoc Ariana Hackenburg Graduate Student Claudio Silva Postdoc Elizabeth Boulton Graduate Student LUX Dark Matter Experiment / Sanford Lab 10 Rick Gaitskell (Brown) / Dan McKinsey (Yale) 10 In Memoriam – Dr. James White A key innovator in xenon dark matter detector technology, a creator of LUX, and a dearly missed colleague LUX Dark Matter Experiment / Sanford Lab 11 Rick Gaitskell (Brown) / Dan McKinsey (Yale) 11 LUX – the Instrument LUX Dark Matter Experiment / Sanford Lab 12 Rick Gaitskell (Brown) / Dan McKinsey (Yale) 12 LUX Construction LUX Dark Matter Experiment / Sanford Lab 13 Rick Gaitskell (Brown) / Dan McKinsey (Yale) 13 LUX – Supporting Systems Xenon gas handling and sampling Thermosyphon Xe storage and recovery cryogenics LN bath conduits Cathode HV feedthrough into cold water head tank LUX Thermosyphon LUX Dark Matter Experiment / Sanford Lab Rick Gaitskell (Brown) / Dan McKinsey (Yale) 14 LUX Timeline LUX funded in 2008 by DOE and NSF Above-ground laboratory completed at SURF in 2011 LUX assembled; above-ground commissioning runs completed Underground laboratory completed at SURF in 2012. LUX moves underground in July to its new home in the Davis cavern. Detector cooldown and gas phase testing completed early February 2013 Xenon condensation completed mid February 2013 Detector commissioning completed April 2013 Initial (3-month) WIMP search. First results presented today! Full year-long WIMP search to begin in 2014. Result in 2015 LUX Dark Matter Experiment / Sanford Lab 15 Rick Gaitskell (Brown) / Dan McKinsey (Yale) 15 LUX Has Exceptional Technical Performance Low-energy electron recoil rate of 3e-3 events/keV/kg/day. Electron lifetime (microseconds)