Casting Light on Antimatter: ALPHA Antihydrogen Experiment at CERN

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Canada’s National Laboratory for Particle and Nuclear Physics Laboratoire national canadien pour la recherche en physique nucléaire et en physique des particules

TRIUMF FIVE YEAR PLAN: INT’L PEER REVIEW NOV 14, 2013 Makoto C. Fujiwara ALPHA-Canada PI Research Scientist TRIUMF

Owned and operated as a joint venture by a consortium of Canadian universities via a contribution through the National Research Council Canada Propriété d’un consortium d’universités canadiennes, géré en co-entreprise à partir d’une contribution administrée par le Conseil national de recherches Canada Antihydrogen Atom

Pbar = antiproton Hbar = antihydrogen, anit-H (bound state of pbar and e+) Outline

• Motivations: “Big Picture” • ALPHA experiment • Recent achievements – Trapping, Microwaves, ALPHA-2 construction • Prospects for next five years – Precision spectroscopy – Gravity • Summary

Makoto Fujiwara, ALPHA 3 Motivations (experimental)

Atomic hydrogen: • 75% of visible universe; one of best studied systems – 1s-2s level: 2 466 061 413 187 035 (10) Hz Δf/f~10-15 – Hyperfine splitting: 1 420 405 751.768 (1) Hz 10-12 Antihydrogen (anti-H): produced in large quantities by ATHENA, ATRAP (2002) • Comparison of H and anti-H: “Textbook” experiment! – Compelling regardless of theoretical motivations

Makoto Fujiwara, ALPHA 4 Big Picture

• What is Particle Physics? (Grossman)

• “Simple answer”: The SM, including Higgs, works extremely well! • Many open issues, in particular: – Naturalness of Higgs mass & Cosmological constant – Require fine-tuning by O(30), O(120)? – Hopefully, LHC & low energy expt’s will solve them! • “L=?” really the right question to ask? Is (effective) Quantum Field Theory correct description of Nature? 5

Antihydrogen Motivations

• Test of CPT – CPT is a fundamental property of local, relativistic Quantum Field Theory – Assuming: Unitarity, Spin Statistics, Lorentz Invariance etc., CPT theorem demands atomic spectrum of H and Anti-H be identical – Violation of CPT would force radical change in theory, incl. validity of QFT – Such probability is low! • Matter-Antimatter Asymmetry in the Universe – CPT violation may be responsible (c.f. Sakharov Condition) • Test of gravity (not in the SM) in regimes previously untested

Makoto Fujiwara, ALPHA 6

ALPHA: Antihydrogen Trapping Apparatus

U. Calgary joined TRIUMF ALPHA consortium as Associate Member • 16 institutions • ~40 physicists ALPHA-Canada • 5 Canadian institutions • More than 1/3 of ALPHA (single largest group) • 10 Faculty/Scientists • 6 grad students • Leadership in detection, microwave spectroscopy, lase cooling TRIUMF • Fujiwara, Olin, Gill (Olchanski, Kurchaninov) + Many Technical people

Makoto Fujiwara, ALPHA 7 ALPHA Experiment Animation

Makoto Fujiwara, ALPHA 8 Antihydrogen Trapped (for 172 ms)

Letter to Nature, Nov. 17, 2010 ALPHA-Canada 15 out of 42 authors (incl. 5 students)

Among top news stories in 2010 – #1 Physics Breakthrough: PhysicsWorld – #1 Most read news: Nature – #2 Science News: CBC National Makoto Fujiwara, ALPHA 9 Example of HQP role: Richard Hydomako (Calgary)

Transporting $0.5M magnet

Richard Hydomako, U. Calgary (responsible for detector analysis) 2011 Thesis Prize Div. Nuclear Phys. Ph.D. thesis published in Canadian Association of Physicists “Best of best” Thesis Series Springer Confinement of Antihydrogen for 1000 s

• Increased trapping rates by x5 (hard to tweak zero) • Trapping time increased by x5000 • “Game changer” Cover, Nature Physics, July 2011 Issue – Opens up many possibilities Principle author: Fujiwara (TRIUMF) • Detailed studies of dynamics

11 First Spectroscopy on Antihydrogen Atoms

Canadian-Lead Initiative: Walter Hardy (UBC), Mike Hayden (SFU) M. Ashkezari (SFU), T. Friesen (Calgary) S. Stracka, D. Gill, A. Olin MCF (TRIUMF)

Makoto Fujiwara, ALPHA 12 Microwave-induced Positron Spin Resonance (PSR)

Installation at CERN, July 2011

– Developed at SFU/UBC/TRIUMF – Trap ~1 Anti-H/20 min – Irradiate with mW • Drive transition: trapped  un-trapped • Look for annihilations – Multivariate (blind) analysis • improved S/N by x10 13

It worked! Big Relief!

Letter to Nature, March 2012 Principal author: Michael Hayden (SFU) • First spectroscopic measurements on anti-H!!! – Precision limited: O(10-3) – Demonstrates it’s possible to do spectroscopy on a single anti-atom at a time – “Historic!” – Nature Editor – Annihilation detection: key – Major Canadian-led success

Makoto Fujiwara, ALPHA 14

Precision Spectroscopy with ALPHA-2

Makoto Fujiwara, ALPHA 15 2012-: ALPHA-2 Construction

• New apparatus for laser and microwave spectroscopy • Very complex design & construction job for cryostat • Unique TRIUMF contributions – Cryo-engineering – Precision welding – Canadian industry (PAVAC) – >3000 hours of machining at TRIUMF and Calgary CERN Bulletin November, 2012

Canadian contribution recognized!

Makoto Fujiwara, ALPHA 17 Precision Laser Spectroscopy with ALPHA-2

“Hänsch Plot” 1s-2s two-photon spectroscopy

• Doppler effect cancels • High precision in matter sector • “Lamp post”

Makoto Fujiwara High Precision NMR of Antihydrogen Ashkezari (SFU), Friesen (Calgary), Evetts (UBC): Hayden, Hardy • Nuclear Magnetic Resonance • Complementary to laser exp – Antiproton spin flip – Sensitivity to Planck scale- suppressed effects (~1/M ) – Broad maximum at 0.65 T Pl – Challenge: compatibility with – Insensitive B field homogeneity! trap/plasma requirements -6 – Initially at few kHz (~10 ) – Simulations with Laxdal,  <100 Hz (<10-7) TRIUMF

PRL 42, 1042 (1979) Hardy et al. UBC

Resonator Prototype at SFU (Q ~ 300)

19 Towards Measurement of Gravity on Antimatter

Antimatter Gravity Experiment • Does antimatter fall down? Apple Anti-apple – Experimental question! (e.g. Lykken et al, arXiv:0808.3929) – If anti-H is laser-cooled to mK G G? 1/2kT=mgh Vertical trap：h~1 m – Anti-H “gas” will sag due to gravity – Position sensitive detection via annihilations • Canadian initiative with increasing interest within ALPHA – Recently decided to expand into gravity – Initially a few %, eventually 10-6 measurement of g H • Conceptual design of experiment & Vertical detector in progress trap • Laser cooling essential step

Anti-H Laser Cooling proposal (2013) • Laser cooling – Provides cold, high density, spatially confined sample – Needed for high precision experiments & gravity • Realistic proposal [Donnan, MCF, Robicheaux, J. Phys. B. 46, 205302 (2013)] – Cooling from 500 mK to 20 mK Anti-H energy Time evolution (0-200 s)

22 Lyman-alpha spectroscopy & cooling M. Michan (Ph.D.), T. Momose (UBC), MCF (TRIUMF)

Lyman-alpha source (122 nm) • UBC Development – Required for laser cooling – Broad band source demonstrated – Technically challenging (Summer 2012)! – Highly non-linear processes in a – 0.15 µJ per pulse : Sufficient gaseous medium power for initial exp.  M. Michan Student Poster Prize @ CAP 2013 • Narrowband source being developed st -7 602/202nm – 1 optical spectroscopy at 10 level – Cooling from 500 mK to 20 mK – Getting ready for 2014 beam as Kr/Ar 4WM Canadian-led initiative 121 nm Chamber

23 Summary

• ALPHA addresses fundamental questions • Achievements in present 5Y Period – Antihydrogen trapped (Nov, 2010) – Confinement for 1000 s (June, 2011) – First spectroscopy measurement (March, 2012) – Constructed ALPHA-2 • Significant Canadian contributions spearheaded by TRIUMF – Intellectual leadership – Infrastructure support for university researchers • Prospects for next 5Y Period – Precision laser and microwave spectroscopy – Antimatter gravity measurement – ELENA: new upgrade ring at CERN in 2017 • Exciting future ahead! photos

Our Hard-working Students Recognized CERN Homepage “Andrea Gutierrez, Ph.D. student from UBC”

Hydomako Thesis (Calgary) published as book: Springer “Best of Best” Thesis Series (20 downloads, since Jan.)

CBC CBC News News Finnish paper

CBC TV

CBC Calgary Sun News 25 Canada’s National Laboratory for Particle and Nuclear Physics Laboratoire national canadien pour la recherche en physique nucléaire et en physique des particules

Thank you! Merci!