the three standard models - g2pc1.bu.edug2pc1.bu.edu/leptonmom/talks/wilczek.pdf · 03/01/2003...
TRANSCRIPT
The Good, the Bad, and the Ugly
The Three Standard Models
The Good: The Gauge Sector
03/01/2003 Frank Wilczek, MIT 3
03/01/2003 Frank Wilczek, MIT 4
Self-Transcendence
03/01/2003 Frank Wilczek, MIT 6
03/01/2003 Frank Wilczek, MIT 7
03/01/2003 Frank Wilczek, MIT 8
• Economy in quantum numbers and coupling strengths
• Stability of the electroweak scale
• Appearance of a large mass scale:
Advantages of Unification and (Low E) Supersymmetry
neutrinos,gravity, things that don’t happen!
• Small Radiative Corrections
• Light Higgs Mass
• Dark Matter Candidate
More Advantages of Susy
03/01/2003 Frank Wilczek, MIT 11
03/01/2003 Frank Wilczek, MIT 12
03/01/2003 Frank Wilczek, MIT 13
The Bad: Gravity
• General relativity + minimal coupling: economical, algorithmic - and works!
• No practical problems (GPS, astrophysics)
• No “immediate” conflict with quantum theory
What’s so Bad?
• Ultraviolet catastrophe
• Singularities: black hole, big bang
• Isolation (vs. unification scale, inflation)
• The Cosmological Term
Refusals of Service
An Opening?
Non-minimal gravitational couplings play a crucial role in supersymmetry models.
The Ugly: Masses and Mixings
• Why three families?
• No deep principles in this sector; many independent parameters
• More accurately, no new deep principles - QM, QFT + renormalizability still rule
Problems
03/01/2003 Frank Wilczek, MIT 20
03/01/2003 Frank Wilczek, MIT 21
• More stuff to determine: CKM matrix, neutrino mass matrix, mu-md
• Higgs particle(s) and couplings
• Axions in themselves: strong P,T; dark matter
• Axions as a clue: symmetry, dynamic “parameters”, ultralight particles
Deuglification: Insights and Opportunities
• Proton decay
• Other rare decays, b›s channels
• xyHiggs2 quartic couplings, hhfsf
• Precision dipole moments
More Opportunities
... which bring us to
The Sublime
The World as Concept, Algorithm, and Number
Hadron Mass Spectrumfrom Quarks and Gluons
Hadrons are the constituents of atomic nuclei. Thecomputation of their mass spectrum from thedynamics of more fundamental quarks and gluonshas been a principal subject of interest in particlephysics.In this figure, the results from the CP-PACS andfrom a previous computation are compared withexperiment. Experimental results are reproduced towithin about 5–10%. With the precise data from theCP-PACS, we further clarify a limitation of thewidely adopted "quenched" approximation,answering a long-standing question since 1981.
N = (u,d,d)L = (u,d,s)K = (d,s)
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
f
K
K* N
LS
X
D
S*X*
W
CP-PACS (1998)GF11 (1993)experiment
quenched QCD
mhad[GeV]