Douglas Bryman University of British Columbia Seeking New Physics with Rare Decays Early Adventures at TRIUMF and Future Prospects JMP Retirement Symposium 2012

1/10/2016JMP2 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

3 COSMOLOGICAL EVOLUTION, BBN LEPTOGENESIS? New Physics Higher Mass Scales? Direct production of new particles

4 Light Particle Rare Decay Experiments Exotic Searches New physics if seen; SM effects are negligible. BSM Physics New physics if deviations from well- calculated SM predictions occur : 7 events < < : 4x10 5 events Early TRIUMF Experiments – Still being pursued today! < State of the Art Jean-Michel and Renee were important contributors to many experiments.

Seeking Answers with Rare Decays Cartoon from Jewish Daily Forward (1920’s) Not exactly the mainstream

6 Lepton Flavor Violation ≈ Observation means new physics. Some SUSY models predict BR(  → e  ) near the experimental limit ~ Observation means new physics. Some SUSY models predict BR(  → e  ) near the experimental limit ~ SM SUSY Muon Decay e

1/10/20167 History of Some Rare Decay Experiments Lepton Flavor Violation 90% CL Future: Many new experiments coming. From Marciano, Mori, Roney 2010 D.B. Thesis TRIUMF TPC… (1987) TRIUMF µ->eγ 1977 TINA+MINA Hincks, Pontecorvo

1/10/ – 10 8  /sec, 100% duty factor LXe for efficient  detection Solenoidal magnetic spectrometer 10 7 – 10 8  /sec, 100% duty factor LXe for efficient  detection Solenoidal magnetic spectrometer MEG Experiment at PSI S. Ritt Goal B< (0.01 x prev. exp)   e  Current result ( ) data B < (90% c.l.)

JPARC: DeeMee Aoki et al. 1/10/2016Doug Bryman JMP Symposium9

10 Singles experiment mitigates high rates. Background (decay-in-orbit) known and calculable. High resolution detector feasible. Possible improvement x 10 4 Lobashov (1980): Solenoid Pion Collector; flux x Proposals:

S=0 J=0

-Leptoquarks -Excited gauge bosons -Compositeness -SU(2)xSU(2)xSU(2)xU(1) -Lepton Flavor Violation -Extra dimensions… -Heavy neutrinos R-parity violating SUSY Others Marciano… Ramsey-Musolf… Non-standard Higgs couplings

1/10/2016JMP Symposium13 TRIUMF 1 PSI 1 TRIUMF 2 PIENU (TRIUMF 3) PEN (PSI 2) Goals (±0.05%) Theory (±0.008%) (±0.33%) Experiments

14 e+e+ Precision goal: <0.05% Large solid angle (x10)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 TrackingSilicon Strips & WC Tracking –Much improved tracking –Detect Decay-In-Flight  for tail correction High resolution calorimeterHigh resolution calorimeter –BINA resolution 2 times better than TINA Use of 500 MHz fast digitizersUse of 500 MHz fast digitizers –Good separation between  ->eν and  -> µ ->e  beam 50 cm

1/10/2016JMP Symposium15

1/10/ 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. Simulations: With Photonuclear Sans Photonuclear Data

1/10/ Energy Spectrum

PIENU Time DATA and Fits Low EnergyHigh Energy Expected Error Budget:

1/10/ 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.