Yuzik, Are you a theorist ? Saturday, Jul 8 2006

Isaac Pomeranchuk
© Moscow Engineering Physics Institute (state university), 2002

Via Amar, I came to know of an interesting quote attibuted to a physicist called Pomeranchuk. In the words of L.B.Okun

When I became a student of Pomeranchuk in 1950 I heard from him a
kind of a joke that the Book of Physics has two volumes: v.1. is “Pumps
and Manometers”, v. 2. “Quantum Field Theory”.

As I read this quote, I suddenly realised that I know near to nothing about Pomeranchuk ! So, after some digging around I came across a short biography at ArXiv. According to the author of that biography,

In 1934-35 his [Pomernachuk's] advisor became Alexander Iosifovich Shalnikov (1905 – 1986).
Many years later academician Shalnikov recalled that he started by bringing
Yuzik to a room full with old vacuum pumps glass-ware and leaving him
there. Two weeks later, entering the room, Shalnikov found that everything
that could be broken was broken. ‘Yuzik, are you a theorist?”, – uttered
Shalnikov. “I don’t know. And what?” – was the answer.

And hence the title of this post .

As you might expect, apart from the above biography, it is very difficult to find material on Pomeranchuk on the web. So, I would rether list here some miscellaneous links dealing with his work.

Approach to Absolute Zero – 4. Below 10 milli-Kelvin by R Srinivasan , A Resonance article has a section on Pomeranchuk cooling.

If a mixture of liquid and solid
³He is compressed isentropically
below 0.3 K, part of the liquid turns into solid absorbing heat
and the temperature of the liquid falls. This is the principle
of Pomeranchuk cooling.

And to quote the wikipedia article on Pomeron,

In physics, the Pomeron is a force-carrying pseudo-particle postulated in 1961 to explain energy behavior of soft hadronic collisions at high energies. It appeared first in the framework of the phenomenological Regge theory of strong interactions at high energies, but later a similar object was derived from the first principle QCD calculations.

The existence of the pomeron as well as some of its properties have been reasonably well established experimentally, notably at Fermilab. In particular, it is believed that the pomeron carries no net charges. The absence of electric charge implies that pomeron exchange does not lead to the usual shower of Cherenkov radiation, while the absence of color charge implies that such events do not radiate pions.

This is in accord with experimental observation. In high energy proton-antiproton collisions in which it is believed that pomerons have been exchanged, a rapidity gap is often observed. This is a large angular region in which no outgoing particles are detected.

The name honors the Ukrainian physicist Isaak Pomeranchuk for his theoretical work in 1960’s on high-energy scattering.

Some other articles on Pomeron :

• From http://ed.fnal.gov/painless/pdfs/diffraction.pdf

… An alternative view of the proton-antiproton collision
is to consider that something carries momentum from the
scattering proton to the antiproton. This exchanged “thing”
is called the pomeron, after the Russian physicist Isaak
Pomeranchuk (1913-1966). Thirty years ago Pomeranchuk
proved important and fundamental theorems about particle
and antiparticle scattering at very high energies. It is this
theoretical entity, the pomeron—not really a particle but
sometimes behaving like one—that we hope to understand.

• Study of central rapidity gaps in events with a leading anti-proton, from Plain English Summaries of CDF Results issued by the Collider Detector at Fermilab
• “It’s the Higgs or nothing” , a Frontiers article
• Probing the pomeron, a CERN Courier article

What ultimately controls the way particles interact? Different particles appear to interact at high energies in similar ways through a mechanism known as pomeron exchange. Sandy Donnachie explains what we know about the pomeron.

And I would be happy to include any other link about Pomeranchuk which might turn up in the comments section.