Steve Sharpe
Professor of Physics
Department of Physics, University of Washington
I joined the
particle theory group in the
Physics Department at the University of Washington in 1988.
My current research interests focus on
lattice gauge theory, in particular the development of methods to calculate
multiparticle properties given lattice results for the finitevolume spectrum.
I am also involved in the calculation of weak matrix
elements which are needed to constrain the Standard Model
of particle physics, and have worked previously
on the very neat idea of "largeN reduction",
whereby in the limit of the large number of
colors one can reduce the volume of the theory to
a single point.
I am a member of the Particle Data Group (link below), and of the
Flavo(u)r Lattice Averaging Group (link below),
and am an editor of
JHEP .
I am also a member of the
ExoHad topical collaboration .
My present student is
Wilder Schaaf (expected graduation in 20267).
My previous graduate students
are Keith Clay (1995, joint with Steve Ellis,
Emeritus Professor and Chair of Physics
at Green River Community College), Yan Zhang (1997, was postdoc at Beijing U.,
presently running a company in Beijing),
Noam Shoresh (2001, joint with David B. Kaplan, first postdoc at Boston U,
now on the research staff at the Broad Institute, Cambridge, MA)
Ruth Van de Water (2005, first postdoc at Fermilab, second
at Brookhaven National Lab, now senior staff member at Fermilab),
Jackson Wu (2005, postdocs at Triumf, Vancouver,
at University of Bern, Switzerland, at Univ. of Alabama,
present whereabouts unknown),
Andrew Lytle (2009, postdocs at Univ. Southampton, England,
at TIFR, Mumbai, India, at U. Glasgow, Scotland, at Rome, Italy,
and a U. Illinois),
Max Hansen (2014, postdoc at Mainz, Germany, staff at CERN, now faculty
at U. Edinburgh)
Derek Horkel (2016, postdoc at Temple U., now working in industry),
John Lombard (2018, now working in industry),
Tyler Blanton (2021, postdoc at Maryland, now in industry),
Fernando RomeroLopez (2021, student at U. Valencia for whom I was
the coadvisor with Pilar Hernandez; postdoc at MIT, faculty at U. Bern),
Huangyu Xiao (2022, postdoc at Fermilab),
and
Zack Draper (2024, aiming to work in industry).
I was also the unofficial advisor of Greg Kilcup (1986, student at Harvard,
now faculty at Ohio State Univ.) and Mateusz Koren
(2013, visiting student from Krakow, postdocs in Madrid and DESYZeuthen,
now working in industry).
Postdocs I have worked closely with and/or mentored are Jim Labrenz
(now at Pacific Biosciences, SF),
Weonjong Lee (now faculty at Seoul National Univ.),
Stefan Durr (now staff at Wuppertal Univ.),
David Lin (now faculty at NCTU, Taiwan),
Barak Bringoltz (now in industry in Israel),
and
Sebastian Dawid (at UW 202225).
 Teaching

Publications:
INSPIRE,
Google Scholar

CV (6/2024)

Selected talks and lectures (most recent on each topic):

"Threeparticle formalism for multiple channels:
the etapipi + KKbarpi system in isosymmetric QCD,"
Contributed talk at Lattice 2024, U. Liverpool, UK, July 29, 2024.

"Multiparticle scattering amplitudes from lattice QCD,"
Invited talk at
"Amplitudes 2024",
IAS, Princeton, USA
June 12, 2024. (Video
here. )

"Progress in calculating multiparticle amplitudes from lattice QCD,"
Bay Area Particle Physics Seminar, SFSU, October 13, 2023.

Overview and status of methods for 3 particles ,
invited talk at
"Lattice QCD and Probes of New Physics,"
workshop in Sante Fe, New Mexico, August 711, 2023

Resolving the lefthandcut problem in lattice studies of the doublycharmed tetraquark ,
contributed talk at Lattice 2023, Fermilab, July 30th  August 4th, 2023.

Lectures on "Multiparticle scattering from lattice QCD"
at
"Methods of Effective Field Theory and Lattice Field Theory",
DPF summer school at Bad Honnef, Germany, July 17  28, 2023.

(1)
Introduction to resonances in (continuum) QCD and derivation of twoparticle quandtization condition

(2)
Implementing the twoparticle quantization condition; deriving the threeparticle quantization condition

(3)
Applications of the threeparticle quantization condition

"Generalizing the LellouchLuscher formula to threeparticle decays,"
talk at HADRON 2021, July 28, 2021

"View from the front line: simulations of quantum chromodynamics and the continuum limit"
invited talk at
Workshop on Constructing Quantum Theories,
University of Washington, May 1, 2021 (recording available at website)

"Lattice QCD: successes, challenges and future outlook",
colloquium at University of Adelaide, February 15, 2019.

"Phase structure of Wilson and twistedmass fermions in the
presence of isospin breaking",
seminars at the University of Mainz and Bonn, July 15 and 18, 2016.

"Future of Chiral Perturbation Theory for Lattice QCD",
invited talk at Technical University MunichIAS symposium on
"Effective Field Theories and Lattice Gauge Theory",
May 19, 2016.

"Can EguchiKawai reduction provide a practical method for
studying largeNc theories on the lattice?"
,
invited lecture at Cracow school of Theoretical Physics,
Zakopane, Poland, June 29, 2013.

Updated lectures on
"Effective field theories for lattice QCD"
at
"New Horizons in Lattice Field Theory"
Natal, Brazil, March 1327, 2013

(1)
Overview and introduction to continuum chiral perturation theory.

(2)
Continuum ChPT completed: Adding sources; Nexttoleading chiral Lagrangian;
Examples of results; Heavy kaon ChPT; Finite volume effects in ChPT.

(3)
Including discretization errors in ChPT (mainly for twistedmass fermions)

(4)
Partially quenched QCD and partially quenched ChPT plus
a discussion of whether m_up=0 is ambiguous.

Talk
at workshop on new fermion discretizations,
Feb, 2012, Yukawa Institute, Kyoto, 2012.
This talk has 2 parts. The first is
an investigation of whether one can use one staggered
fermion to study the lightest four physical flavors (u,d,s,c). My conclusion
is that it is impractical.
The second part is an analysis of the symmetries, vacuum and pion spectrum
of two types of "staggeredWilson fermions": that proposed by Adams having
2 light fermions, and that proposed by Hoelbling (and its variants)
having either 1 or 2 light fermions. I conclude that the former scheme has
a number of attractive properties, while the later suffers from rotation
breakdown in the continuum limit, unless one adds counterterms and fine tunes.

Talk
at ECT* workshop on "Chiral Dynamics with Wilson fermions",
Oct. 2428th, 2011, Trento, Italy.
This gives an introduction to Wilson Chiral Perturbation Theory
and the predictions for the phase structure at nonzero lattice
spacing, and presents some new work with student Max Hansen.

An old but still relevant plenary talk
(at
Lattice 2006, Tucson, Arizona, July 2328, 2006)

Selected conferences and schools organized:

I am a member of the
SWME
(Staggered fermion Weak Matrix Element)
collaboration.

I am a member of the
Particle Data Group
, updating with Shoji Hashimoto (KEK) the
minireview on Lattice QCD (v6: 2024)
(initially written in 2011 with Jack Laiho (Syracuse) and Shoji Hashimoto).

I am a member of the
Flavo(u)r Lattice Averaging Group
, which provides averages of results relevant for flavor physics
from lattice calculations. Our latest review (2021) is
here
(published version) or
>
here (arXiv).
(See also web version with downloadable figures on FLAG website.)

I am an emeritus member of the executive committee of the
USQCD
collaboration, which has obtained support from DOE
for computational resources and support.
Teaching (future, recent, plus some old classes)
 SPRING 2025, 2022, 2021, 2020, & 2018 (behind Canvas firewall) and SPRING 2011 (open):
Physics 519:
Graduate QM (third quarter).
 WINTER 2022, 2021, 2020 (behind Canvas firewall) and WINTER 2011:
Physics 518:
Graduate QM (second quarter).
 AUTUMN 2021, 2020, 2019 (behind Canvas firewall) and AUTUMN 2010:
Physics 517:
Graduate QM (first quarter).
 SPRING 2024 (behind Canvas firewall)
Physics 558:
High Energy Physics, part 2.
 WINTER 2024, 2023, 2018, & 2017 (behind Canvas firewall)
Physics 557:
High Energy Physics.
 AUTUMN 2016 & SPRING 2016 (behind Canvas firewall) & AUTUMN 2015 (open)
Physics 226:
Particles and Symmetry.
 WINTER 2016 (behind Canvas firewall):
Physics 122:
Introductory E&M.
 SPRING 2017, AUTUMN 2022 and 2023 (behind Canvas firewall):
Physics 507:
Physical Applications of Group Theory.
 WINTER 2015:
Physics 228:
Elementary Mathematical Physics, Part 2.
 AUTUMN 2014:
Physics 227:
Elementary Mathematical Physics, Part 1.
 SPRING 2023 (behind Canvas firewall) and 2014:
Physics 578A:
Lattice Field Theory and its Applications.
 WINTER 2009:
Physics 486 and 495:
Seminar on Current Problems in Physics and Senior Honors Seminar.
 AUTUMN 2008:
Physics 505:
Graduate Mechanics (and an introduction to chaos).
 AUTUMN 2005:
Physics 121A:
Mechanics.
 SPRING 2004:
Physics 123B(H):
Waves (honors section).
 WINTER 2004:
Physics 122B(H):
Electromagnetism and Oscillatory Motion (honors section).
 AUTUMN 2003:
Physics 121B(H):
Mechanics (honors section).
US mail: Stephen R. Sharpe
Department of Physics
University of Washington
Box 351560
Seattle, WA 981951560
Office: B406 PhysicsAstronomy Building
Email: srsharpe@uw.edu
Phone: (206) 6852395
FAX: (206) 5435923 or 6850635
Steve Sharpe
<
srsharpe@uw.edu>
Last modified: 3/21