Freedom from Symmetry: Six Years of the Higgs Particle

A “cephalopod diagram” of Higgs decay, with vector boson final states in red and fermion final states in blue. Solid lines correspond to final states we’ve definitely seen, and dashed lines represent final states still being hunted. The area of a circle represents its relative rate to that of the bottom-quark final state, which is expected to represent 60% of all Higgs boson decays.

Six years ago on this date, the Higgs boson was (probably) discovered by the ATLAS and CMS Experiments at the Large Hadron Collider in Geneva, Switzerland. I say “probably” because, at the time, all we really knew for sure was that we had discovered a new particle, with a particular mass (about 126 times the proton mass, at the time), that appeared in our experiments in ways consistent with, but not unique to, the predicted Higgs particle.

Well, it’s been 6 years and 1 Nobel Prize in physics since then, and we’re all pretty darn sure it is the Higgs boson predicted in the early 1960s.

But wait. Is it? ATLAS and CMS continue to map out its detailed properties, including one of the biggest sets of prizes in the current data set being collected right now: how much the Higgs boson interacts with the top quark, the heaviest of the 6 known quarks, and the bottom quark, the second-heaviest quark. It’s an unfolding story.

Meanwhile, check out these blog posts from me back in July of 2012, and remind yourself of how glorious it is to see something no one has ever seen before.

Relive the moments before and after the announcement of the “bump” in the data from my friend, Aidan Randle-Conde, who was at the time a post-doctoral researcher at SMU and an avid blogger and science communicator:

“Reality in the Shadows (or) What the Heck’s the Higgs?” is meant to help a new audience come to discover a love of science and especially physics, or to welcome to the frontier those who already discovered that love a long time ago.

And, of course, with further hindsight and many more years of data to inform the discussion, learn more about just what the heck’s the Higgs in our book, “Reality in the Shadows (or) What the Heck’s the Higgs?” by S. James Gates, Jr., Frank Blitzer, and me!

While we know more about this particle since discovering it in 2012-2013, there are many mysteries left. Some prizes are big, but hard to claim in all the noise. For instance, only just a year ago, we spotted the first strong hints of the direct interaction of the Higgs particle and the bottom quark… despite the fact that this should be its favored method of decay! Learn more here:

UPDATE (July 6, 2018): Added the really nice “post-seminar analysis video” from Aidan and some more words about how data in the intervening years has shed light on some questions but left others open.

A Dialogue with Anonymity: Reviews of Spring 2018 PHYS 1303 (Introduction to Mechanics)

A look at anonymous student course feedback and responses to some of their written comments.

Faculty often have a lot to complain about when it comes to course evaluations. A significant body of literature suggests that course evaluations tell us little, as instructors, about the actual effect a course has had in achieving its goal (e.g. imparting a subject to a group of students).  However, one of the social problems that, I think, we have with course evaluations is that it’s not a dialogue or conversation; it’s a set of one-sided statements that come, all at once, around the time final grades are posted. The comments can be reflective, not of the value or rigor of the course, but rather the emotional state of the student in anticipating of the final grade they have earned in the course. They can be vacuously enthusiastic or bitter. They are often treated by the institution as definitive, without opportunity for faculty to respond to them.

I wish to turn this problem part-way around and make it, not a dialogue, but at least a response. I think it’s important to respond to student comments, especially the ones that are critical of the course in specific ways (e.g. due to another influence that soured them on the course, due to experiences with grading, etc). In speaking back to the commenters, anonymous though they may be, I hope to also provide something more resembling the “closed loop” of a real dialogue. At the very least, I can achieve one cycle of “call and response”.

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CERN Travel Journal: June 17 – 24, 2018


A view along a road inside CERN, bordering a vineyard on the south side. The sun is setting over the Jura Mountains.

What an incredible week. Not only was the weather a strange cycle of “uncomfortably hot” and “beautifully cool”, but the sheer pace of work this week was blinding. There was time to relax a little, too, as when the weekend came I had dinner with an SMU alumna and her husband – the person whom I met on the plane on my way to CERN a few weeks ago. There was a ton of research, some reflection on the U.S. in lieu of being here at CERN, and a lot of walks and runs around CERN, along with some wonderful opportunities to take photos that mix nature and scientific infrastructure.

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CERN Travel Journal: June 10 – 16, 2018

Four views of CERN from this week, spanning the entire set of weather conditions. It was great week.

This was a glorious week at CERN. Being away from the United States for a little while, in place that is both host to the complications of international cooperation and a reminder of how things can actually be when people of different nations cooperate well, has been an out-of-body experience for me as an American. It’s been a good thing. Of course, apart from what’s been good for the soul, there has been much research, which is great for the mind. Computer craziness ahead of a deadline, lots of data to copy, an analysis to run from scratch, and new views on old problems filled my week. I’ll reflect a little on this here.

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