The abbreviation CMS stands for one of the currently largest physics experiments worldwide. Günther Dissertori, a particle physicist at the Swiss Federal Institute of Technology (ETH) Zurich, was recently appointed to the three-headed spokesperson-team of the CMS experiment, which is located at the large particle accelerator at CERN in Meyrin near Geneva. The 47-year-old scientist has to cope with a task that can be compared to the management of an international company with 4,000 employees.
The Compact Muon Solenoid (CMS) is one of the two largest experiments running at the LHC particle accelerator at CERN since 2009. The greatest success of the CMS experiment so far is the discovery of the Higgs boson in 2012 (together with the ATLAS experiment, the other large experiment at the LHC). Some 4,000 scientists, engineers, technicians and administrators are involved in this major experiment. If you count only the researchers with a PhD degree, there are still 1400 persons from 196 academic institutes around the world. For the on-going operation of the CMS experiment, including the computation for data processing, a few hundred people are needed at CERN.
These figures show how much effort it may take to keep such an experiment on course. As a rule, the CMS experiment is guided by a three-headed spokesperson-team: a "spokesperson" and his two deputies. The term "spokesperson" is, however, misleading, as the "spokespersons" are not simply providing information. They rather are responsible for the operational management of the experiment. "The three-headed spokesperson-team has an executive management task. Although there are a couple of differences, their tasks are comparable to the activities of the CEO of a multinational company, " says Prof. Günther Dissertori. The particle physicist of ETH Zurich was appointed deputy spokesperson for CMS in autumn 2016. The appointment was made by the current spokesperson - the US scientist Joel Butler - and was confirmed by the 198 institutes of the CMS collaboration.
The new pixel detector will be installed in 2017
Nowadays large physics experiments have usually an international membership. It is therefore always a special recognition when physicists from Swiss institutes are represented at the spokesperson level. Dissertori's appointment to the management of a LHC experiment follows the tradition of Dr. Peter Jenni, who led the ATLAS experiment from 1995 to 2009, and of Tatsuya Nakada (EPF Lausanne), who led the establishment of the LHCb experiment at CERN as a spokesperson from 1995 to 2008. In order to be able to fulfil the new task during a two-year term, Dissertori had to significantly reduce his teaching responsibilities at ETH Zurich. His mandate requires a strong presence at CERN (about 3 days / week) and a lot of travelling. The CMS spokesperson team interacts closely with the CERN directorate and, together with the two so-called physics coordinators, is also ultimately responsible for the publication of the results of the CMS experiment. Currently, the CMS experiment produces around 100 scientific publications per year.
A first major milestone of the two-year term at the top of the CMS experiment is expected in spring 2017, with the replacement of the pixel detector, a key component of the CMS detector. Like the current detector, the new pixel detector was designed under Swiss leadership (PSI, ETH and University of Zurich) and is intended to make the CMS experiment even more powerful in the future. As a CMS Deputy Spokesperson, Dissertori has to look into the distant future as well: "Already now we have to prepare the upgrades of the CMS detector that we want to do in 2024-2025," says Dissertori. “We have to talk to the national research funding agencies, to plan technical implementation details and their documentation, and to organize the division of tasks between the involved particle physics institutes."
Strong motivation required
Whoever conducts a large physics experiment must be an excellent physicist and a skilled manager, but also a good communicator and sometimes a talented motivator. This is particularly important in situations as in the first half of 2016, when the eyes of the scientific community were directed at CERN, because new data nourished hope for a breakthrough discovery, which later turned out to be a statistical fluctuation. "Such situations of disappointment must also be handled somehow," says Dissertori. "As a spokesperson-team, we have to ensure that the motivation is kept high."
An important prerequisite for being able to cope with the challenges faced by the spokesperson triumvirate of CMS is a good network within the particle physics community worldwide. Günther Dissertori was able to further expand his network in autumn 2016. The prestigious American Physical Society (APS) chose the native South Tyrolean as one of its fellows – “for pioneering work in quantum chromodynamics measurements in colliders, leadership in the discovery of the Higgs boson, and enabling searches for new physics at the Large Hadron Collider, as well as his effective efforts to promote international collaboration and help smaller countries develop exchanges for vibrant physics research.” as the APS has pointed out in its citation.
Author: Benedikt Vogel