SEARCHES FOR DARK MATTER PRODUCTION AT THE LARGE HADRON COLLIDER AT CERN FAPESP WEEK LONDON, FEBRUARY 11TH, 2019 Oliver Buchmueller, Imperial College London 1 The Dark Side We now know that only ~5% of the energy in the universe is ordinary matter (remember E=mc2). 25% is “Dark Matter” SuperSymmetry theories can happily predict this amount but here are also other possibilities. The remaining 70% is “Dark Energy” We have fewer good ideas about what this could be but it will probably be taxed someday 22 The Dark Side We now know that only ~5% of the energy in the universe is ordinary matter (remember E=mc2). 25% is “Dark Matter” SuperSymmetry theories can happily predict this amount but here are also other possibilities. The remaining 70% is “Dark Energy” We have fewer good ideas about what this could be but it will probably be taxed someday 33 The Dark Side We now know that only ~5% of the energy in the universe is ordinary matter (remember E=mc2). 25% is “Dark Matter” SuperSymmetry theories can happily predict this amount but here are also other possibilities. The remaining 70% is “Dark Energy” We have fewer good ideas about what this could be but it will probably be taxed someday! 44 The Dark Side We now know that only ~5% of the energy in the universe is ordinary matter (remember E=mc2). 25% is “Dark Matter” SuperSymmetry theories can happily predict this amount but here are also other possibilities. The remaining 70% is “Dark Energy” We have fewer good ideas about what this could be but it will probably be taxed someday! Today I will focus on the 25%! 55 Searches for Dark Matter (&SUSY) Direct Searches DM? Indirect Searches 6 How to Search for Dark Matter? SM ? SM Searching for a particle means to interact with it using known particles in the detector or producing it 7 7 How to Search for Dark Matter? DM Satellite DM Earth Indirect SM SM 8 8 How to Search for Dark Matter? Earth SM Direct SM Underground Collider 9 How to Search for Dark Matter? LHC Earth Indirect SM SM 10 Collider 1 0 How to Search for Dark Matter? DM Satellite DM LHC Earth SM Direct SM Underground Collider 11 DARK MATTER SEARCHES AT COLLIDERS 12 Physics Mission of the LHC • The LHC project (the accelerator and experiments) was conceived & designed to tackle fundamental questions in science (some which go to the heart of our existence): about the origin, evolution and composition of our universe. In particular, what is the origin of mass? what constitutes dark matter? do we live in more than 3 space dimensions? why is the universe composed of matter, and not antimatter? 13 13 This Study Requires……. 1. Accelerators : powerful machines that accelerate particles to extremely high energies and bring them into collision with other particles 14 14 This Study Requires……. 1. Accelerators : powerful machines that accelerate particles to extremely high energies and bring them into collision with other particles 2. Detectors : gigantic instruments that record the resulting particles as they “stream” out from the point of collision. 15 15 This Study Requires……. 1. Accelerators : powerful machines that accelerate particles to extremely high energies and bring them into collision with other particles 2. Detectors : gigantic instruments that record the resulting particles as they “stream” out from the point of collision. 3. Computing : to collect, store, distribute and analyse the vast amount of data produced by these detectors 16 16 This Study Requires……. 1. Accelerators : powerful machines that accelerate particles to extremely high energies and bring them into collision with other particles 2. Detectors : gigantic instruments that record the resulting particles as they “stream” out from the point of collision. 3. Computing : to collect, store, distribute and analyse the vast amount of data produced by these detectors 4. Collaborative Science on a worldwide scale: thousands of scientists, engineers, technicians and support staff to design, build and operate these complex “machines”. 17 17 Timeline of the LHC Project 1984 Workshop on a Large Hadron Collider in the LEP tunnel, Lausanne 1987 Rubbia “Long-Range Planning Committee” recommends Large Hadron Collider as the right choice for CERN’s future 1990 ECFA LHC Workshop, Aachen 1992 General Meeting on LHC Physics and Detectors, Evian les Bains 1993 Letters of Intent (ATLAS and CMS selected by LHCC) 1994 Technical Proposals Approved 1996 Approval to move to Construction (materials cost of 475 MCHF) 1998 Memorandum of Understanding for Construction Signed 1998 Construction Begins (after approval of Technical Design Reports) 2000 ATLAS and CMS assembly begins above ground. LEP closes 2008 ATLAS & CMS ready for First LHC Beams 2009 First proton-proton collisions 2012 A new heavy boson discovered with mass ~125 × mass of proton 2015 RUN2 with 13 TeV operation started Almost 30 years! 18 The Large Hadron Collider at CERN 19 19 The Large Hadron Collider at CERN LHC : 27 km long 100m underground 20 20 The Large Hadron Collider at CERN LHC : 27 km long 100m underground ATLAS General Purpose, pp, heavy ions CMS 21 21 +TOTEM The Large Hadron Collider at CERN LHC : 27 km long 100m underground ATLAS General Purpose, pp, heavy ions Heavy ions, pp ALICE CMS 22 22 +TOTEM The Large Hadron Collider at CERN pp, B-Physics, CP Violation LHC : 27 km long 100m underground ATLAS General Purpose, pp, heavy ions Heavy ions, pp ALICE CMS 23 23 +TOTEM 24 24 Electro-weak phase transition (ATLAS, CMS…) 25 25 Electro-weak phase transition (ATLAS, CMS…) QCD phase transition (ALICE…) 26 26 Electro-weak phase transition (ATLAS, CMS…) QCD phase transition (ALICE…) LHC studies the first 10-10 -10-5 second after the big bang!! 27 27 Characterisation of Dark Matter searches at colliders Simplicity vs. Complexity Finding the right balance is a challenge! 28 Characterisation of Dark Matter searches at colliders Simplicity vs. Complexity Finding the right balance is a challenge! 29 Characterisation of Dark Matter searches at colliders Simplicity vs. Complexity Finding the right balance is a challenge! 30 Dark Matter in Supersymmetry with MasterCode Global Fit to indirect and direct constraints on SUSY! 2008 Pre-LHC Source: 2008 http://mastercode.web.cern.ch/mastercode/ Pre-LHC 2008 Pre-LHC 31 Dark Matter in Supersymmetry with MasterCode Global Fit to indirect and direct constraints on SUSY! 2008 Pre-LHC Source: 2008 http://mastercode.web.cern.ch/mastercode/ Pre-LHC 2008 Pre-LHC Jonathan Costa, final year PhD Student at Imperial College London. He is sponsored by a fellowship of the Brazilian Science Without Borders programme via CNPq 32 Gluino vs Squark: LHC RUN 1 pMSSM11 w/o LHC13 : best fit, 1σ, 2σ 4000 3500 3000 2500 2000 [GeV] ˜ g m 1500 1000 500 0 0 500 1000 1500 2000 2500 3000 3500 4000 4500 m [GeV] q˜R 33 Gluino vs Squark: LHC RUN 2 (2015 + 2016 data) pMSSM11 w LHC13 : best fit, 1σ, 2σ 4000 3500 3000 2500 LHC Impact 2000 pushing the [GeV] ˜ g coloured mass m 1500 Scale! 1000 500 0 0 500 1000 1500 2000 2500 3000 3500 4000 4500 m [GeV] q˜R 34 Characterisation of Dark Matter searches at colliders Simplicity vs. Complexity Finding the right balance is a challenge! 35 Dark Matter Constraints: Simplified Models “allowed region” To be published in The European Physical Journal C See http://mastercode.web.cern.ch/mastercode/publications.php for full MasterCode publication list 36 Summary Ø So far New Physics has not revealed itself! Ø By 2010 the LHC has enter new territory for New Physics searches and since pushed e.g. the (coloured) SUSY mass scale to the ~1 TeV scale Ø We were well prepared for an early discovery but we also knew that it could take more time and ingenuity before we can claim a discovery (if NP exist) Ø The LHC experiments have established an impressive variety of very powerful direct searches for many different final states! Ø Based on these results we need to establish the “big picture” in order to understand if/where our search strategy might have weak spots or even holes! Ø This requires appropriate interpretations of the searches and a MEANIGFUL comparison with other experiments – important example DM searches! Ø We have still almost two decades of data taking in front of us, with a factor 100 increase of statistic still to come! The story continues … 37 BACKUP 38 DARK MATTER – A Particle?! Known DM properties 39 DARK MATTER – A Particle?! Known DM properties • Gravitationally interacting 40 DARK MATTER – A Particle?! Known DM properties • Gravitationally interacting • Not short-lived 41 DARK MATTER – A Particle?! Known DM properties • Gravitationally interacting • Not short-lived • Not hot 42 DARK MATTER – A Particle?! Known DM properties • Gravitationally interacting • Not short-lived • Not hot • Not baryonic 43 DARK MATTER – A Particle?! Known DM properties • Gravitationally interacting • Not short-lived • Not hot • Not baryonic Clear evidence for a new particle(s)! 44 (Very Strong) Evidence for Dark Matter G. Bertone 45 (Very Strong) Evidence for Dark Matter G. Bertone 46 History of Dark Matter in a Nutshell G. Bertone 47 .