We provide below links to web pages containing many of the internal group documents from the E288 Columbia-Fermilab-Stony Brook experiment at Fermilab --mostly from the year (6/1976 to 6/1977) leading to the Upsilon discovery. Some of these notes, labelled "Private", "Do Not Make Public", etc. were internal notes when we were on the verge of a discovery, and was afraid of information being leaked to outside before we were ready to announce the discovery. Thus, many of these are of great historical significance, giving insight to the process of a "discovery in progress".
Some other significant notes outside that period are also included, such as important notes and developments leading to the original E70 and E288 proposal, as well as some brief notes and comments on recent consequences of this discovery and the significance of Bottom quark to HEP physics currently.
Leon's groundbreaking dimuon experiment at Brookhaven National Lab (BNL) saw the first evidence of the J/Psi, subsequently discovered in 1974 by Ting (Di-electron at BNL) and Mark 1/Richter (detector at SLAC--Stanford Linear Accelerator Center). Pity that Leon's mass resolution was not better, and that his data was published before the GIM model predicted Charm (J/Psi is the Charmonium--made up of a Charm quark and a Charm anti-quark)--we show here a plot of the dimuon mass distribution, with a broad peak near 3 GeV.
The early phases of this progression of experiments concentrated on the study of single electrons produced at large angles from proton-nucleus collisions, and coincide with the commissioning of the Fermilab Main Ring accelerator, which accelerated protons up to an energy of 200 Gev, subsequently upgraded to 400 GeV.
The Fermilab PAC (Program Advisory committee, which recommends which experiment to approve) asked Leon to define in more detail the di-lepton phase of the E70 experiment, and subsequently issued a new experiment number E288 to that phase.
Gaillard, Lee and Rosner paper, which predicted the J/Psi discovery, lay out in great detail the Charm system which will be discovered soon. In fact, Mary K. Gaillard told Leon and me (JKY) over lunch at Fermilab in Aug. 1974 that Leon's BNL bump is the Charmonium.
Leon responded that he has been looking for that, with an experiment at CERN ISR looking at di-electrons from 1970 onwards (J/Psi signal swamped by unexpected high Pt photons from Pi-zero decays as well as poor calibration problems) as well as the experiments which has already started at Fermilab --E70, E288, etc. Looking at Single e, muon, di-e, and di-muon. He was too slow--the J/Psi was discovered while E70 was still investigating single e's.
Why did we brashly named the 6.0 particle Upsilon (though in the PRL paper, we soften this
name to describe either the 6.0, if confirmed, or the entire high mass di-lepton region). Here's
some thoughts --
(1) Jeff Weiss research the Greek Letter, and found 4 possibilities --we don't like iota (?)
So, Upsilon sounds a promising name. Furthermore, Walter Innes (I think) points out that if
the particle is not confirmed, we could call it OOpsLeon. Due to our heritage (our Spokesman
is well know for bad puns), we could not resist.
(2) There are at least 2 additional events which barely fail our cuts. If these were included,
the significance would be at least 1/2 sigma higher--but, like most HEP physicists, we are
sufficiently honest that we never thought of tuning our cuts to generate a better looking signal.
(3) Our experiment only look at one mass plot, unlike others that looks at hundreds of
plots; so, a 2-1/2+ sigma effect is significant for us--while other experiments would expect to see
many such statistical fluctuations in their hundreds of plots.
November 17, 1976, about 7-1/2 Months before the Upsilon discovery, E288 had a first hint of the Upsilon(9.5). John Yoh(JKY), experiment coordinator, was responsible, among other things, in taking the data tapes to the computing center, perform the first stage data reduction, and verify that the data is good ("Bicycle On-line")--which include a first look at the dilepton mass distribution. On that date, he wrote an internal note ("***DO NOT MAKE PUBLIC***") "From the people who brought you the Upsilon (6.0), a bigger (but not necessary better) resonance.
The note discribe a cluster of 10 events within a 300 MeV wide window, where one would expect (based on adjacent bins) 1.75 events. The significance is stronger than the original Upsilon (6.0), which was not confirmed and was determined to be a statistical fluctuation. The 9.5 significance is roughly 1 in 160, vs. 1 in 50 for the 6.0.
Fortunately, we did not have to decide then whether to annouce yet another new resonance, since we know that our forthcoming Mumu2 phase (due to start in March 1977) , with 100 times higher sentitivity per day, would settle the veracity of the 9.5 within weeks (well, it actually took 2 months due to the fire that disrupt data-taking for 1+ weeks).
Nevertherless, John Yoh, put a bottle of French Champagne (Mumm's ??) in the trailer control room refrigerator, with 9.5 written on it--to be open when discovery is confirmed).
John Yoh replied to Bob/Bud that some of the events nearby could be part of the resonance, thus broadening the peak.
The E288 MuMu2 experiment, which discoverd the Upsilon, the particle made up of a Bottom and an Anti-bottom quark, is a collaboration of CFS (Columbia university, with Leon Lederman as Spokesman and John Yoh as Experiment coordinator, Fermilab --with Taiji Tamanouchi, senior member, and Stony Brook, with Bud Good senior member). The CF group which originated the experiment (from the early 1970's E70 stages), were joined by the Stony Brook (SUNY--State University of New York at Stony Brook) group in 1976 for the E494 di-hadron phases and subsequently the MuMu2 phase.
The members of the experiment at the time of the Upsilon discovery include (see some examples of many of their contributions to the preparation of the MuMu2 detector below--note that many more notes exists but we don't have room for all of them)
Columbia :
LML (Leon Lederman,Spokesman and originator of the experiment),
JKY (John Yoh, experimental coordinator 1975-1977, data reduction expert)
SWH (Steve Herb, upgrade manager--reconfiguration of the target box, absorber)
DH (David Hom)
JCS (Johannes C "Hans" Sens)
HDS (H. David Snyder)
Fermilab :
TY (Taiji Yamanouchi, senior member)
JAA (Jeff Appel, experimental coordinator 1973-1975 while working for Columbia)
BCB (Bruce C Brown --detector expert--construction of new wire chambers)
CNB (Chuck Brown)
WRI (Walter Innes, reconstruction software)
KU (Koji Ueno, Monte Carlo expert)
Stony Brook
ASI (Al Ito)
HJ (Hans Jostlein)
DMK (Dan Kaplan, graduate student--whose wrote his thesis later on the Upsilon
discovery results--he is also responsible for online compuitng)
RDK (Bob Kephart)
Previous members who left prior to the discovery
David Saxon
Jean-Paul Repellin
Maurice Bourquin
Jeff Weiss
Engineers and Technician that played strong roles in the preparation of our detector
Bill Sippach (electronics)
Karen Kephart, Ken Grey, Frank Piersall, Jack Upton
Many others, too many to name
Members of Fermilab accelerator division, Proton division, etc.
This undated plot (probably March-April 1977) shows the older ee1/mumu1 results (on top) compared with the test run results at the bottom--there is some evidence of excess events near 9.5 in the short 1-week test run (152-163)-- though the evidence is not yet compelling.
The results of data collected in the periods 5/14-5/21 and 5/28-6/4 (the one week downtime was due to the fire in the detector hall) indicated a 9.5 bump of at least 8 sigma significance. we start to get a to-do list to verify this bump--making sure that this is not due to some artifact such as detector problems, etc.
Efforts are being made to study this resonance, which has by that time reached 10+ sigma statistical significance. So, we are mainly concerned now with whether some experimental defects (artifacts) could cause such a peak. Many studies are detailed in this note--as well as other notes.
Some more studies, on the way to a publication and discovery announcement.