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Seeking New Physics with Rare Decays Early Adventures at TRIUMF and Future Prospects. Douglas Bryman University of British Columbia. JMP Retirement Symposium 2012. Standard Model : A great story … but definitely not the whole story….
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Seeking New Physics with Rare Decays Early Adventures at TRIUMF and Future Prospects Douglas Bryman University of British Columbia JMP Retirement Symposium 2012
Standard Model : A great story …but definitely not the whole story… • Cosmological issues: inflation, dark matter, dark energy, matter anti-matter asymmetry… • Theoretical issues: gravity, neutrino mass, flavor problem, hierarchy problem, divergences .… + Higgs JMP
Energy Frontier New Physics Direct production of new particles Precision Frontier Flavor Physics DARK Matter Frontier Higher Mass Scales? COSMOLOGICAL EVOLUTION, BBN LEPTOGENESIS?
Light Particle Rare Decay Experiments Early TRIUMF Experiments – Still being pursued today! Jean-Michel and Renee were important contributors to many experiments. State of the Art <2.4 10-12 <7.8 10-13 10-4: 4x105events 10-10: 7 events <2.6 10-8
Seeking Answers with Rare Decays Not exactly the mainstream Cartoon from Jewish Daily Forward (1920’s)
Lepton Flavor Violation e Muon Decay SM SUSY ≈ 10-13 • Observation means new physics. • Some SUSY models predict BR(m → eg) near the experimental limit ~10-12.
History of Some Rare Decay Experiments Lepton Flavor Violation Hincks, Pontecorvo D.B. Thesis TRIUMF µ->eγ 1977 TINA+MINA Future: Many new experiments coming. From Marciano, Mori, Roney 2010 TRIUMF TPC… (1987) 90% CL
MEG Experiment at PSI m e g Goal B<1.310-13(0.01 x prev. exp) • 107 – 108m/sec, 100% duty factor • LXe for efficient g detection • Solenoidal magnetic spectrometer Current result (2009-2010) data B <2.410-12 (90% c.l.) S. Ritt
JPARC: DeeMee Aoki et al. Doug Bryman JMP Symposium
Proposals: Lobashov (1980): Solenoid Pion Collector; flux x 1000. • Singles experiment mitigates high rates. • Background (decay-in-orbit) known and calculable. • High resolution detector feasible. • Possible improvement x 104
J=0 S=0
Non-standard Higgs couplings Marciano… Others R-parity violating SUSY -Leptoquarks -Excited gauge bosons -Compositeness -SU(2)xSU(2)xSU(2)xU(1) -Lepton Flavor Violation -Extra dimensions… -Heavy neutrinos Ramsey-Musolf…
THEORY Experiments Theory (±0.008%) PIENU (TRIUMF 3) PEN (PSI 2) Goals (±0.05%) (±0.33%) PSI 1 TRIUMF 2 TRIUMF 1 JMP Symposium
Precision goal: <0.05% • Large solid angle (x10) • More statistics • Lower energy dependent acceptance difference • Detect shower leakage (CsI) for low energy tail • measurement (biggest systematics) • Silicon Strips & WC Tracking • Much improved tracking • Detect Decay-In-Flight for tail correction • High resolution calorimeter • BINA resolution 2 times better than TINA • Use of 500 MHz fast digitizers • Good separation between ->eν and ->µ->e e+ beam 50 cm
Photonuclear Effects in NaI(Tl) Detectors A positron beam was injected into the NaI(Tl) Extra structure (bumps) were observed – simulation confirms that multiple neutron emission is responsible. Data Simulations: With Photonuclear Sans Photonuclear
PIENU Time DATA and Fits Low Energy High Energy Expected Error Budget:
Summary: Rare Decays For more than two decades Jean-Michel and Renee Poutissou made many important contributions to successful TRIUMF experiments searching for and measuring rare decay processes.