4/13/13

Alright, so I decided to take notes throughout the sessions I attended at APS April and effectively post them like a liveblog, but after the fact when all was said and done.

Here’s Saturday:

Conference day started with Kavli sessions; (only thing of note before then is that the first person to approach me in Denver was trying to sell me weed on my way to the conference -.- and that Herman Winnick liked my jacket XD)

8:30:

John Harris and Lattice QCD
Degrees of freedom increase with energy and level off after some number of MeV.
~175 MeV => Deconfinement
As T-> T_c, confinement potential decreases, rather than looking exponential as you increase the distance between quarks, you level off and then dip dowards.

RHIC 5-200 GeV, LHC 2.76- 5.5 TeV

ALICE has great pictures: http://www.symmetrymagazine.org/sites/default/files/breaking/wp-content/uploads/2010/11/ev71_3D.png

What is gluon shadowing? Strong flow? QGP has ultralow viscosity.
Initial conditions vary, n/s goes up, distribution smears out??
Ideal hydro is n/s=0 [n is actually an eta!!]
Excesses produces over the NLO predictions, why not go to NNLO…?
Color screening should happen, J/Psi and Upsilon should see this?

Labs go towards “hot” QGP, but neutron stars are “cold” and are dense, but low temperature in comparison.

9:00 am David Wineland.
One/two item system => macroscopics is silly – Schrdoinger
Wineland’s career started with precision msmts, and stuck to them.
Hans Dehmelt was influential in electron trapping/
If you shine a laser below the resonant frequency, atom cools. Use noise to detect the temp.
Goal is to isolate indiv. ions, Barium has a blue line…you can literally see a single atom!
Long life time => short wavelegth, hard for transitions.
State depndt fluorescence good for detection w/ quantum information.
After moving up to D5/2 re-emit in a delta n = 0 process,
So you reduce number by in the upper region then drop it down.
Conditional dynamics are good for logic gates.
Trapping kills off first order doppler effects -> 7 x 10^-17 accuracy below Cs clocks.
When the traps are down to 4K, coherence time increases from 10 min to months. optical clocks definitely beat cesium.

Laser has spin-dep force => super position of states motionally and spin. 80 nm, roughly microscopic compare to atom sizes.

Peter Shor – efficient factorization of large N in 1994,
Ekert presents Shor’s ideas at a Phys conference,
Zoller & Cirac 1995 PRL – mapping process that allows for entangling quantum states and performing quantum calculations.

Gravitational redshift becomes relevant at precision they can measure, hence optical clock is also a meter stick if you know g very well 😛
C.W. Chon 2010?

9:42  Planck results from Lloyd Knox at UC Davis.
SET and ACT have higher resolution msmts than Planck, but less frequencies.
They provide great consistency checks, though! 4 sigma ACT, 6 sigma SPT…Planck? 25 freaking sigma.
Stacking analysis is cool.
Radiation dominated era is over a massive scale factor change…
Density fluctuations came from a ~ 10^-45
“We are amplified quantum fluctuations” proposed as an alternative to “we are star stuff” lololol
As and Ns parametrize fluctuations, rho_r and gamma weak eq?
Reionization parametrized by a_rein

Decompose data into nodes; intermediate nodes have the greatest flux.
Sound horizon at last scattering determines the middle wiggles in the angular anisostropy
Diffusion length suppresses low angles.
Offset exists between Planck and WMAP on first bump…this is bad, and is not well understoof.
Use sound horizon -? a~10^-3 note that this produces angles visible on galactic scales. 2.5 sigma away from H0

David Tong was on a slide! Woooooo

B sessions? Yep. Those came next.

Shoji Hashimoto -KEK, Precision Lattice QCD.
“Valid in principle” Gimme money, get results.
1. Start with QCD L, give it alpha_s and m_f…ignore top mass or set it huge, I guess? mu=md and these are taken from mass of pion…this is isospin approx. Mass of mc and mb only relevant in valence and ms is taken from kaon properties.
We can now reproduce mass spectra for hadrons and the lepton decays constants!
We need to use theory to constrain Lattice Calculations.

alphaS is well predicted, Lattices take alpha-bare?
Nucleon charge radius fails though.
Pion data not great, why no m_pi^2 calculations at the experimental values…? [this was effectively answer later!]
2. What else can we do? Gold-plated processes…only one strongly interacting particle in final or initial state. Avoid strong decays. Spatial p small compared to [huh]?
K-> pi pi, K0 to gamma gamma 2012 gave first F_(pi)(g)(g) results.
Analytic constraints allow us to extend successful models to other processes.
Disconnected diagrams matter for some reason? This I should ask about…

3. 2-5 years from now?
Discretization effects need to be taken care of, such as finite volume. New Blue Gene Q at KEK, more reason to love Japan right now.
1% precision => need to break isospin, need to use QED.
Biggest problems? Statistical errors D:
q~ exp[- m_pi |x-y|]  stats only improve as 1/sqrt N :/
Long distance correlations grow with decreased pion masses…hence the above question’s answer about why we don’t use lower pion masses in calculation.

Random undergrad session? Random undergrad session.
E. Gross worked on a spark chamber. I think I’m going to email him. Sadly, it was tiny 😦 the good new is that it took about a year for one dude and a mentor. They do NOT have a nice machine shop at Regis University…so we have an advantage at Tech. Primary reasn for building is outreach. 100 K sparks per day…this is good and bad since you can burn out your electronics :/

====books===
Griffith’s has a new book on revolutions in physics
Maggiore has a QFT book…may check that out this summer, it looked stupid thorough 😛

11:57 MICHAEL PESKIN, WOOOOOO -Higgs talk.
What is mass? Take complex scalat field, mass term is coeficient on |phi|^2 term. This has the effect of producing an energy gap of 2mc^2 in the space of allowed energies.

Energy splitting is not allowed with symmetry. Breaking the symmetries give mass. L&R  handedness for e- no problem when particles travel at speed of light…but you can boost. So you can mess things up. Parity violations occur.
e-_R is a single, but (nu E)_L form a doublet, SU(2) \times U(1)
Weak interaction produces massive vector bosons…but the expressions [almost indistinguishable from Maxwell’s eq] for the fields do not allow a mass. These masses are produced by introducing and extra field.
Similar field in Landau super conductor.
We break the symmetry and collapse to U(1). The effective lagrangian generates the mixing we need ($\lambda \bar{e}_R \phi^\dagger (\nu e)_L + h.c. $ [I just discovered, I think, that wordpress does latex…we’ll see].
BR for most useable channels are super small! $h \to ZZ^* \to 4 l$ is .16%, $h \to 2 \gamma$ is .23 \% $
Gauge structure vs. vacuum structure. Why top so heavy?
CP violation L, B violation vacuum energy?

Lots of questions need addressing on the vacuum side of things.

Cosmic Ray Talk [nature’s super colliders] Fermi Mechanism? Shocks give great energy boosts.
Diffusive Shock Acceleration is important.
Strong Shock -> R=4=>E^-2
Hadron acceleration harder to see, pion to gamma gamma we CAN see.
100x normal galactic magnetic fields for Tycho.
Fields are amplified by CR-induced streamings. Cosmic rays acceleration and push waves, v up gives B up.
Galactic diffusion ~ GeV but are shocks efficient? Self-generated shocks give 10^6 GeV.

Collisionless shock- collective E&M effects.

Meet Wald, got an awesome picture with him 😀 …his talk was half incomprehensible though…BH Thermodynamics in d-dimensions?

LGQ with Pullin was like 35% understandable…but I also walked in late.

New Collider in Japan looks cool, Kaoru Yokoya? 1984 ish studies into the ILC began as a Japanese initiative. 2004 ILC becomes a thing when Japan realizes they want it…but don’t want to do it alone.
500 GeV at least for e+e- to Higgs. 31 k, ~8 billion dollars and 9 years.

LOTS OF CODE AND STUFF WOOOOOOOOOOOOOOOOOOOOOOOOOOO
Finished almost all of my presentation that night…almost.

 

European Coffee Shops are sketch …

 

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