The text below is the third part of what could have become "Chapter 13" of the book "Anomaly! Collider Physics and the Quest for New Phenomena at Fermilab", which I published in 2016. For part 1 see here; for part 2 see here.

Giromini joins Run 2

While all those preparations were reaching their final stages, Paolo Giromini was busy with the completion of his Run 1 analyses. He had originally refused to add his name to the list of Run 2 authors, thereby formally joining the new experiment. He stood faithful to his judgement that embarking on a massive upgrade of the detector and accelerator complex, after having spent a decade to make the whole thing work and finally starting to milk it for beautiful physics results, was a big mistake: an uncalled-for jump in the dark. The detector, in his opinion, should have continued to take good data for many more years without the long interruption, yielding among other things a quicker answer to the questions that his analyses were posing. When I questioned him on the upgrade he burst out in laughter: "E' un casino allo stato liquido! Non funzionerà mai" ("It's liquid-state mess, it will never work" - the expression "liquid-state mess" belongs to the realm of figurative speech commonly used by Italians of Tuscan origin).

Maybe Giromini really believed that the completion of the CDF upgrade would take many years longer than anticipated. For sure he had fresh in his memory the problems that CDF had withstood in its infancy, when it had taken a long time to produce the first usable data after the completion of detector construction, and even more time to make sense of them. The complex tasks included the non-trivial finalization of the trigger system and the understanding of its output, the calibration of detector response, and the challenging issues connected to the reconstruction of particle trajectories from the information produced by the tracking detectors. Or maybe Giromini was just taking a stand against what he considered a bad scientific decision.

As my career path was on the line -as a new post-doctoral scientist who needed to produce valuable new scientific results, I had to decide where to put my chips, i.e. whether to invest all my time in the new CDF II detector or rather turn my attention to the construction of the CMS experiment at CERN- I was of course interested in catching the reason of Giromini's stand. However, despite my attempts at discussing the matter objectively I never managed to get anything more than jokes and derisory statements from him. He used to argue that it would take a decade to understand the new trigger; that the management was inept and incapable of bringing the project to completion as planned; that money would run out; that the accelerator would not manage to produce a stable beam at the higher intensity, such that the silicon detector would be fried by the beam swerving off its orbit.

I tend to believe that on the whole Giromini was not serious, and that his claims that the upgrade would somehow fail were part of his constant joking attitude, this time directed toward an experiment he loved and hated at the same time. Even Fotios Ptohos, who had spent a long time in the company of his boss and had inherited some traits of Paolo's attitude, used a lot of sarcasm when he talked about the upgrade, and especially about the project I was working on, the CMX. At the end of 1998, as a post-doctoral scientist hired by Harvard University, I had started to work on the upgrade of the central muon extension, a system of drift tubes sandwiched by scintillator sheets which identified muons emitted from the collision point at angles between 45° and 60° with respect to the beam. Completing the instrumentation of that angular region, which had only been partly covered before the start of Run 1, was one of the hardware contributions to CDF II of the Harvard group, to which Fotios himself belonged. As a graduate student he had spent endless days standing several meters above ground on flimsy ladders leant on the CMX arches, in order to install components, get the system to work properly, or perform repairs on the fly. He talked of the muon chambers as if they were a living body. "I'm telling you: be careful, the CMX kills!". He loved the detector he had helped build, but he was very sceptical that its upgrade would be completed smoothly.

Above: yours truly next to one arch of CMX chambers, during upgrade work in the CDF collision hall, 1999. The photomultiplier tubes reading one end of the scintillation sheets are visible.

As bit by bit things slowly came together and Run 2 indeed begun, the attitude of Giromini started to change. Indeed there had been delays and setbacks, but now data were starting to trickle in, and he realized that his forecasts of doom had been too pessimistic. The new Run now offered a chance to reach a definitive conclusion on the many puzzles he and his group had banged their head on; his analyses, in the meantime, were not leading to any definitive conclusion on the presence of new physics in data collected in Run 1. Giromini was slowly managing to publish his work, although piecemeal, amended, and lowered in scope (see Chapter 12); but the case those papers made was not strong enough to convince the scientific community that CDF had seen the first indications of a new physics signal. Already in November of 2001 -just as the first Run 2 data were being written to mass storage- he had inquired with the spokespersons about the possibility of being accepted as a CDF II member. The minutes of the CDF Executive Board of November 15th 2001 in fact report:

"It was agreed that Paolo Giromini would be considered for membership as a Run 2 collaborator once he has followed the standard rules for application as a new individual senior collaborator."

That was no red carpet: his twenty-year-long service in CDF during Run 0 and Run 1 would not grant him a wild card. Yet all he had done until then had been a preliminary inquiry: he had made no explicit formal step yet. Giromini only made a formal move in the summer 2003, when he declared to the spokespersons of the experiment that he intended to join the CDF II collaboration as a senior member from the Frascati group. Frascati as a group was of course part of CDF II, so all that was needed was to accept him in the ranks. Yet this raised a clear problem: Giromini had not contributed to the upgrade in any way until then. There was no record of cable shifts, test beam shifts, or upgrade activities under his name in the "CDF II people database". Officially, Giromini had left collaboration when CDF had made the transition to CDF II. Also, he initially did not garnish his application with a proposal of what service work he would be performing by joining the upgraded experiment. As the Executive Board had clarified two years earlier, rather than a transcription of a name from the Run 1 author's list to the Run 2 one there would need to be a formal presentation in front of the representatives of the participating institutions, a detailed proposal, and a formal approval process.

In retrospect the strict application of those rules to Giromini looks a bit petty: the Italian scientist had provided such crucial contributions to the existence and functioning of the detector in Run 1 that the request to formally commit to some additional service and maintenance work for CDF II could have easily been waived. Besides his expert contributions to the design and construction of the central hadron calorimeter, a revered device which had worked without a glitch for over a decade and was still happily taking data in the upgraded detector, Giromini had to his credit a large number of important contributions to the commissioning and operation of various subsystems of the experiment. His past contributions easily trumped those of most of his colleagues, as well as the list of agreed tasks contained in the "Memorandum of Understanding" that bound the other Frascati members and CDF II. It was thus only natural to expect that he would continue to attend and contribute to the good performances of the upgraded detector as he had consistently done in the course of the past two decades, regardless of signed paperwork. But the spokespersons explained that rules would have to be followed.

Giromini was undeterred. He had finally decided to keep working in CDF, and nothing would make him change his mind: for sure not the feeling of being unwelcome, to which he was by then well accustomed, or the formal request to put together a detailed proposal to join the experiment. He could choose to move to another project now that his analysis of Run 1 data had come to its logical conclusion: his status of research director within the INFN (an equivalent title to that of full professor) allowed him to freely decide to join another experiment, or even to propose an entirely new project. However, Paolo was stubborn, and he felt that Run 2 would finally provide him with answers to the questions he had fought so hard to bring up with his Run 1 analyses. He was convinced that Supersymmetry, or even something ever subtler, was hiding in plain sight, and he just needed ten times more data to silence the fiercest of his opposers, and win the final battle.

[Continues in part 4]