All posts by John Donoghue

Back From Zurich

I have had the pleasure of spending 10 weeks at the Universitat Zuerich. Hopefully I will soon be able to report on the results from that visit. I worked with Daniel Wyler on the Regge region in SCET and on the vectorial standard model. Both are interesting and hopefully important. I am now back at UMass.

Spring semester

This spring I have a research leave from teaching. I am still supervising grad students, administering our grant and doing departmental service. However, my main focus is on developing a new research program on emergent theories, and the extra time is extremely valuable in allowing this to happen. I will be on leave at the University of Zurich from March 11 until May 16. I can still be contacted by my usual email during this period.

At the moment, I expect to be in Amherst all summer.

My anthropic paper with Thibault Damour

Here is my most recent paper.

In this paper, Thibault and I study the range of masses for light quarks that leads to nuclear binding. There are two calculations involved, which are used to provide estimates for how nuclear binding depends on quark masses.

The quark masses enter the Standard Model as parameters that are not fixed by any principle. It turns out that if they were slightly different, nuclei would not bind and there would be no atoms, and then no life. If we eventually learn that there is indeed a principle that fixes the quark masses, then this observation is just a bit of amusement. However, it is also possible that the mass parameters may not be fixed uniquely and could be different in different parts of the Universe. In that case, we would only find ourselves in the part of the Universe where the masses fall into the anthropically allowed range. In such theories the anthropic bounds could then play a role in determining the values of the masses.