Beyond the God Particle (56 page)

Our advice is that you hug your children and call your Mom and tell her you love her.

4
. See “Neutrino oscillation,”
http://en.wikipedia.org/wiki/Neutrino_oscillation
(site last visited 3/28/13).

5
. Recall from
chapter 6
: The L electron carries a weak charge, and R does not. Weak charge must also be conserved, but the Higgs field has filled the vacuum with a large reservoir of weak charge. So, L can convert to R by dumping its weak charge into the Higgs field reservoir; and R can convert to L by absorbing the weak charge back again out of the Higgs field reservoir, making L. But the Higgs field does not absorb or relinquish
electric charge
, so the L electron must have the same charge as the R electron; the R positron must have the same charge as the L positron.

6
. See “Ettore Majorana,”
http://en.wikipedia.org/wiki/Ettore_Majorana
(site last visited 3/26/2013). The term “Majorana particle” is now commonly used but is erroneous, because the particle is actually one with a “Majorana mass.” The term “Majorana particle” was historically reserved for spin-1/2 particles whose wave functions are real, which can only occur in special space-time dimensionalities, like 2, 6, 8, 10, etc.

7
. See “Neutrinoless double-beta decay,”
http://en.wikipedia.org/wiki/Double_beta_decay#Neutrinoless_double-beta_decay
(site last visited 3/26/2013).

8
. This is called the “neutrino seesaw mechanism,”
http://en.wikipedia.org/wiki/Seesaw_mechanism
(site last visited 3/26/2013).

9
. See “Leptogenesis (physics),”
http://en.wikipedia.org/wiki/Leptogenesis_%28physics%29
(site last visited 3/26/2013). Quoting from the source:

The Big Bang produced matter and antimatter directly, but in nearly equal amounts. Today, however, we see no antimatter left in the universe. The cosmic annihilation of matter and antimatter should have been almost complete, leaving not nearly enough leftover matter to form the billions of stars that we see today, and us. Where did all this matter come from? Or, where did all the antimatter go? The process of leptogenesis could be the answer. Neutrinos are very different from other kinds of matter, and may be the only matter particles that are their own antiparticles. Neutrinos also have very tiny masses which suggests that the origin of neutrino mass involves much shorter-range interactions with hypothesized superheavy neutrinos. This may provide an experimental window to leptogenesis. When theorists rerun the tape of the Big Bang introducing superheavy partner neutrinos with nonstandard CP symmetry, the result is leptogenesis. The heavy neutrinos fall apart into light neutrinos, producing an excess of matter over antimatter. In the hot environment of the early universe, this excess is quickly passed along to all the particles that we are made of. If the theory of leptogenesis is correct, we owe our existence to neutrinos from the big bang.

10
. See “Bruno Pontecorvo,”
http://en.wikipedia.org/wiki/Bruno_Pontecorvo
(site last visited 3/26/2013).

11
. See “Raymond Davis,”
http://en.wikipedia.org/wiki/Raymond_Davis_Jr
. and “Homestake experiment,”
http://en.wikipedia.org/wiki/Davis_Experiment
(sites last visited 3/26/2013).

12
. See “Masatoshi Koshiba,”
http://en.wikipedia.org/wiki/Masatoshi_Koshiba
(site last visited 3/26/2013).

13
. See “Super-Kamiokande,”
http://en.wikipedia.org/wiki/Super_Kamiokande
(site last visited 3/26/2013).

14
. “How Does NOnA Work?”
http://www-nova.fnal.gov/how-nova-works.html
. See “Neutrino oscillation,”
http://en.wikipedia.org/wiki/Neutrino_oscillation
(sites last visited 3/26/2013). It's important to realize that we did not dig a 500-mile-long tunnel from Fermilab to Soudan, Minnesota—the neutrinos propagate freely and unimpeded through the earth under Wisconsin (Go, Packers!).

15
. Fermilab is playing an active role in this development with a trial liquid argon detector experiment called MicroBooNE: “ArgoNeuT,”
http://www.fnal.gov/pub/science/experiments/intensity/argoneut.html
; “MicroBooNE,”
http://www-microboone.fnal.gov/
(sites last visited 3/26/2013). Liquid argon-based time-projection chambers are also under active study for dark matter and neutrinoless double-beta decay detection, addressing the issue of Majorana vs. Dirac neutrino masses.

16
. See “Proton decay,”
http://en.wikipedia.org/wiki/Proton_decay
(site last visited 3/26/2013).

CHAPTER 11. PROJECT X

1
. “The Shutdown Process,”
http://www.fnal.gov/pub/tevatron/shutdown-process.html
(site last visited 3/26/2013).

2
. John Matson, “
Life after Tevatron: Fermilab Still Kicking Even Though It Is No Longer Top Gun
,”
Scientific American
(January 2012),
http://blogs.scientificamerican.com/observations/2012/01/31/life-after-tevatron-fermilab-still-kicking-even-though-it-is-no-longer-top-gun/
(site last visited 1/23/2013). The lessons from the Tevatron are interesting. The top quark was initially thought to be light, about 90 GeV, and it should then have been seen in the first year of running. However, the top quark has turned out to have a very large mass of 172 GeV, and this required several years of patient searching until evidence for it finally emerged at the Tevatron, followed by a bona fide discovery in 1995. Had the top quark been about 60 GeV heavier we may never have found it at the Tevatron.

It was estimated in 1991 that, if the Higgs was lighter than about 140 GeV, the Tevatron could see it with 30 inverse femtobarns of data. The Tevatron luminosity increased significantly, due to the heroic efforts of the Fermilab Accelerator Division, to the point that it became clear the Higgs could have been seen with a concerted effort by the lab. The prediction for the required luminosity turned out to be right on the nose, but unfortunately the Tevatron ended operations, having delivered one-third of the required Higgs discovery's integrated luminosity. Still, the decay mode, by which there is now some evidence of the Higgs boson at the Tevatron, is the decay of Higgs into a b quark + anti–b quark final state. This decay mode is very important to our understanding of the Higgs properties. But this mode, and other “matter decay modes,” of the Higgs will be established in the all-important LHC run, due to commence January 1, 2015.

3
. See Fermilab's Project X website:
http://projectx.fnal.gov/
; in particular, one can access the “Project X Book” at this site, which gives comprehensive literature on the experimental program and machine and detector designs. See also “Project X (accelerator),”
http://en.wikipedia.org/wiki/Project_X_%28accelerator%29
; “Fermilab's Project X Could Offer Potential Energy Applications,”
http://www.symmetrymagazine.org/breaking/2011/04/12/fermilabs-project-x-may-have-a-potential-energy-application
(sites last visited 1/23/2013).

4
. “Muon Storage Ring”:
http://www.cap.bnl.gov/mumu/studyii/final_draft/chapter-7/chapter-7.pdf
; “Muon Ring Could Act as a Neutrino Factory,”
http://cerncourier.com/cws/article/cern/28043
(sites last visited 1/23/2013).

5
. “The E821 Muon (g-2) Home Page,”
http://www.g-2.bnl.gov/
; “Muon g-2,”
http://muon-g-2.fnal.gov/
(sites last visited 6/24/2013).

6
. See “Neutrino Factory,”
http://en.wikipedia.org/wiki/Neutrino_Factory
(site last visited 4/3/2013).

7
. See “Muon collider,”
http://en.wikipedia.org/wiki/Muon_Collider
(site last visited 4/3/2013).

8
. The charged-kaon decay mode has been previously studied by the Brookhaven E787/949 experiment using a high- intensity stopped-kaon technique to yield a total of seven candidate signal events. The NA62 experiment at CERN is currently pursuing a new in-flight technique with the aim of achieving a 100-event sensitivity at the Standard Model level. The process K
_L
→
π
v
v
is a purely CP-violating process, that is predicted in the Standard Model theoretically at the 1 percent level of precision. The observation and precise measurement of this rare process will constitute a major triumph in kaon physics with the potential of discovering discrepancies. The KOTO experiment at J-PARC in Japan is pursuing a staged approach to reach single-event sensitivity, with an ultimate goal of reaching 100-event sensitivity, at the Standard Model level. This establishes the need for a multi-1,000-event future Project-X-based experiment.

9
. See “Quantum electrodynamics,”
http://en.wikipedia.org/wiki/Quantum_Electrodynamics
, “Richard Feynman,”
http://en.wikipedia.org/wiki/Richard_Feynman
, “Julian Schwinger,”
http://en.wikipedia.org/wiki/Julian_Schwinger
, “Sin-Itiro Tomonaga,”
http://en.wikipedia.org/wiki/Sin-Itiro_Tomonaga
(sites last visited 4/3/2013).

10
. We say that electric fields are vectors (they reflect like velocities or position vectors in mirrors); magnetic fields are “pseudo-vectors” and reflect with an opposite sign in mirrors. One has to be a little careful with this, because with vectors it depends upon the orientation of the system and of the mirror.

11
. Also, it should be noted that EDM experiments provide very sensitive limits on the existence of electric dipoles and have already bitten the theorists in the pants. The current upper limit on the existence of the electron EDM is about 10
^-27
e-cm coming from studying “polar molecules” like Yb-F (see, e.g., “A New Upper Limit on the Electron's Electric Dipole Moment,”
Physics Today
12 [August 2011]). This result already severely constrained the Minimal Supersymmetric Standard Model (MSSM) model, before the LHC arrived on the scene. We believe that supersymmetry has a very good chance of being true, but perhaps only at extremely high and inaccessible energy scales, and perhaps in a novel form that no one has yet conceived of.

12
. See “Electron electric dipole moment,”
http://en.wikipedia.org/wiki/Electron_electric_dipole_moment
, “Neutron electric dipole moment,”
http://en.wikipedia.org/wiki/Neutron_electric_dipole_moment
(sites last visited 4/3/2013).

13
. See “Proton therapy,”
http://en.wikipedia.org/wiki/Proton_therapy
(sites last visited 4/7/2013).

14
. “Accelerator Driven Subcritical Reactors,”
http://www.academia.edu/1684005/Accelerator_Driven_Subcritical_Reactors
; “Accelerator-Driven Nuclear Energy,”
http://www.world-nuclear.org/info/Current-and-Future-Generation/Accelerator-driven-Nuclear-Energy/#.UVX7efKbFXs
(sites last visited 4/3/2013). Much more can be found by searching online for “accelerator driven subcritical reactors.” See also R. P. Johnson et al., “GEM*STAR—New Nuclear Technology to Produce Inexpensive Diesel Fuel from Natural Gas and Carbon,”
Proceedings of IPAC2013
, Shanghai, China.

15
. “Muon Accelerator Program,”
http://map.fnal.gov/
(site last visited 4/7/2013).

CHAPTER 12. BEYOND THE HIGGS BOSON

1
. For in introduction to the cosmological theory, see Steven Weinberg,
The First Three Minutes
(New York: Basic Books, 1977). Search online for “cosmology” and “big bang” for various wiki articles.

2
. See “
Nimitz
-class aircraft carrier,”
http://en.wikipedia.org/wiki/Nimitz-class_aircraft_carrier
, “
Gerald R. Ford
–class aircraft carrier,”
http://en.wikipedia.org/wiki/Gerald_R._Ford-class_aircraft_carrier
; Ronald O'Rourke, “Navy CVN-21 Aircraft Carrier Program: Background and Issues for Congress,”
http://www.history.navy.mil/library/online/navycvn21.htm
(sites last visited 4/7/2013).