Chasing Particles Is Fun

January 15, 2016   •   By Priyanka Kumar

A SINGULARLY UNFEMININE PROFESSION is more a blueprint for a fabulous book than a fully realized one, but it sparks discussion in two intriguing areas that are rarely connected — physics and feminism. Its physicist author, Mary K. Gaillard, spent decades exploring the fundamental forces of nature, and she triumphed in her male-dominated field. However, she needed to harness her “survival mechanism,” or else she wouldn’t have had a career as a physicist of international prominence.

In the 1970s, Gaillard wrote a famous paper on how to discover the Higgs boson, in which she and her collaborators also talked about the decay of the Higgs into two photons. That was the “golden mode” in which a new particle was discovered in 2012 at the Large Hadron Collider at the European Council for Nuclear Research (CERN) near Geneva. In March 2013, measurements of the spin, parity, and decay rates of the new particle confirmed it to be the Higgs boson. This is generally considered one of the most significant recent discoveries in the field of particle physics.

Five years earlier, in March 2008, I was at CERN to put the final touches on a script set in the world of accelerator physics. Here, the search for the Higgs boson had led to the construction of the world’s most expensive particle accelerator. The Large Hadron Collider was international news, attracting its share of weirdos (would scientists suck us down black holes?), and it had graced the front cover of The New York Times more than once. The cool-sounding Higgs boson is named after Peter Higgs, who collected a 2013 Nobel Prize for proposing how the origin of mass of the W and Z bosons can be explained.

But what is the Higgs boson exactly? If you are a general reader, you may not want to look to Gaillard for answers. Chasing particles is “fun” for her, and she discusses her work in some detail, but she does so mostly at the grad-student level. I don’t mean to suggest that this book is for physics aficionados only, but Gaillard does have the physicist’s tic of abruptly breaking into technical explanations without priming us for how deep she plans to go.

CERN has come a long way from its inception in 1954 — today, it boasts a particle accelerator with the world’s most energetic beams. When I toured the Large Hadron Collider complex, the experiment was to begin running in six months, and the anticipation was palpable. I put on a hard hat before I entered the ATLAS experimental area. The first thing to confront me was the staggering size of the machinery. Staring at it, I was like a beetle standing before an unbelievably tall refrigerator with all its wiry guts exposed. An Italian engineer took me up an open elevator, and together we walked into the experiment’s metal body. In the crisscross of railings and wires, an occasional human stood out: a Spanish scientist poring over some numbers; a mechanic hunched over a problem spot with his toolbox; some grinning postdocs.

The longer I stayed, the metal and wire proliferating in all directions took on a beauty of sorts that seemed almost natural. I, with my inability to detect the collisions of subatomic particles, became the anomaly, rather than the other way around. This surreal mind-switch was normal. I was inside the largest particle physics laboratory in the world, a multibillion-dollar collaboration representing over 600 universities and research facilities.

From the start of the experiment, CERN was highly ambitious about what they hoped would be found, and it can be argued that they indulged in too many press releases. In September 2008, the first beams were successfully fired around the accelerator’s almost 17-mile underground tunnel ring. However, approximately 100 “super-cooled” magnets exploded — an embarrassing and expensive glitch — which led to a 14-month hiatus. Still, no one planned to give up.

The Higgs boson was important: it was the last verifiable particle of the Standard Model of Elementary Particles. If you are not familiar with the Standard Model, think back to the chemistry periodic table you studied in high school. The Standard Model is something of the same for particles. It classifies all the subatomic particles known to physicists — leptons, quarks, W and Z bosons, the photon, and the gluon. Between the early 1960s and the mid-1970s, scientists mapped out how these particles interact under the newly discovered fundamental forces of nature — the electromagnetic, weak and strong nuclear interactions.

In the early ’60s, Gaillard was a graduate student at Columbia University, where she met her future husband Jean-Marc, then a postdoc. After marriage, they moved to Paris, and she took physics classes and set up house. She calls that first year (they lived in Orsay, a village on the periphery of Paris) “the worst year”:

I remember our friend Mel Schwartz visiting our apartment and saying: “She will make a great housewife.” Not a very encouraging remark. Years later, Mel learned better, when I had become an expert on kaon physics, and a consultant to his group at the SLAC accelerator at Stanford University.

Schwartz went on to share the 1988 Nobel Prize for discovering the muon neutrino, and in 1991, he became the Associate Director of High Energy and Nuclear Physics at the Brookhaven National Laboratory. Not long after the Orsay sojourn, Jean-Marc Gaillard was offered a six-year staff position at CERN. Meanwhile, Mary K. Gaillard toiled on as a visitor in the theory group at CERN for some 20 years. Several years into her CERN stay, her salary still hovered around the same amount she had made as a summer student at the Brookhaven National Laboratory. It’s not news that particle physics is a male-dominated field. What’s disturbing is that this gender bias is so deeply rooted at the institutional level. A report Gaillard later helped write showed that women held only 3 percent of CERN staff positions.

Gaillard writes about the “determined antifeminism” of the head of her theory group, Léon Van Hove. There were others who told her she’d be better off staying at home and taking care of the kids. Despite the challenges she faced, including being dissuaded early on from becoming a theorist, Gaillard went on to make important contributions to the Standard Model. In the mid-’70s, she and her collaborators predicted the mass of the charm quark. In a 1975 paper entitled “A Phenomenological Profile of the Higgs Boson,” she and her collaborators (John Ellis and D.V. Nanopoulos) were the first to suggest ways to directly search for the Higgs boson. They ended the paper with the following remark:

We should perhaps finish with an apology and a caution. We apologize to experimentalists for having no idea what is the mass of the Higgs boson, unlike the case with charm and for not being sure of its couplings to other particles, except that they are probably all very small. For these reasons we do not want to encourage big experimental searches for the Higgs boson, but we do feel that people performing experiments vulnerable to the Higgs boson should know how it may turn up.

While their paper was still in proofs, Gaillard and her collaborators “learnt of some more considerations about the mass of the Higgs boson” and were “encouraged to calculate its production in neutrino collisions.” This suggests that the idea of a search was beginning to catch on. Over a decade later, it seemed as though the United States would take the lead in the hunt for the Higgs boson. However, the attempt to build the world’s most powerful accelerator, the Superconducting Super Collider in Texas, was shut down by Congress in 1993 allegedly due to the high costs of the project. Meanwhile, Gaillard’s work as a physicist became respected internationally. Still, even as the 1980s began, her status at CERN remained tentative.

Gaillard’s resumé is impressive enough. But she also had three children. How did she do it? She sketches out the answer in this book. There was a daycare at CERN, but it was only half-time, so she had to drive her kids back home for lunch. She found a full-time housekeeper in the cobbler’s wife next door. Along the way, she also hired au pairs, and then au pairs with driver’s licenses, until her youngest, then 12, told her he didn’t want au pairs anymore. What’s clear is that it took the support of a full-time housekeeper and an au pair in the evening for Gaillard to carve out enough time for a career in theoretical physics. Such support is not available to most women. Gaillard was also a hands-on mother, who played games with her children in the evening. She is quick to confess her faults — once, she forgot to pick up her son from a music lesson. In the preface, she thanks her children, “who put up with, and sometimes even encouraged, a working mother.”

Their working mother, however, was stuck in a basement office at CERN and was afraid to complain, in case she lost what privileges she had. As someone who worked out of a basement office at CERN during my two-week stay, the sunny upstairs offices are — trust me — much more desirable. After enduring second-class status at CERN, Gaillard was subject to gender biases even when she graduated to an upstairs office, including finding a disturbing note in her mailbox and being mistaken for administrative help.

Then there was the secretary effect, meaning that if you were a woman you were assumed to be someone who was supposed to help the men. I always had an open-door policy; anyone who wanted to discuss physics was welcome in my office. This resulted in people wandering into my office, after passing all the offices occupied by males, to ask me for directions or some other kind of help.

The way she coped (and resisted the urge to throw books at intruders) was to treat the offensive behavior of others as a nuisance and not allow it to affect her ability to do physics. I wonder if this is when her cigarette habit worsened. I imagine her walking through the CERN complex, cigarette in hand.

The buildings at CERN are mostly gray and off-white — concrete and glass dominate. Today, outside one building is a huge Nataraj (a dancing Shiva) in black, an anomaly — a gift from the Indian government — and a reminder perhaps that scientists here probe the most fundamental and elusive secrets of the universe. Social life revolves around the cafeteria; in the late morning, scientists wander in to get lattes and croissants. They are mostly men. As the commentator Anne-Marie Slaughter and others have argued recently in The New York Times, Americans do a great job of equalizing the gender playing field in high school and university and a less great job of retaining women in the workplace. It seems Europe has a similar problem.

In 1981, UC Berkeley had the good sense to offer Gaillard a faculty position. She was the first woman on their physics faculty, which then consisted of almost 60 active members. Around the same time, her marriage broke up. She does not explain why, although she has told us that in the past Jean-Marc resisted leaving Europe. She writes only, “Jean-Marc and I were separated, and Bruno Zumino and I were together.” At the end of the book, she briefly discusses her secretiveness about the matter.

For all her triumphs, Gaillard’s survival mechanism took its toll. She writes that she became a feminist out of “necessity,” to combat the obstacles she faced while pursuing physics; she saw other female physicists drop out or step back, and even one who committed suicide. Gaillard admits she still smokes, even though she knows it isn’t good for her, and has developed a painful condition of the mouth. While we can celebrate what Gaillard achieved — she is now one of the most distinguished elders in the field — the way forward is by no means clear. Gender-based social conditioning is still widespread, and girls are certainly not entering the field of theoretical physics in record numbers.

Another open question, now that the Higgs boson has been discovered, is the future of collider physics in the United States, and what role the next generation of American physicists will play in the field (given that the central experiment is situated in Europe). What’s clear is that there will continue to be some interesting questions in the foreseeable future and a need for disciplined, creative minds to answer them. We can only hope the door will crack open for more women to have as much fun chasing particles as Gaillard once did.


Priyanka Kumar is an author and a filmmaker. Her feature screenplay set in the world of theoretical physics, A Trillion Different Questions, won the Alfred P. Sloan Foundation Award.