HarryfestP. Grannis April 9, 2018

Man van Staal ??

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Afrikaans title for 1973 movie “Six Million Dollar Man”?

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1999 Dutch movie about a boy’s coming of age?

Afrikaans title for 1973 movie “Six Million Dollar Man”?

Return-path: <WEERTS%MSUPA@fnald0.fnal.gov>Received: from DECNET-MAIL (MAIL$SERVER@FNALD0) byFNAL.FNAL.GOV Date: Tue, 31 Jan 1995 12:38:39 -0500 (CDT) From: Man van Staal <WEERTS%MSUPA@fnald0.fnal.gov>Subject: Worry about .... To: PGRANNIS@fnalv.fnal.gov

1999 Dutch movie about a boy’s coming of age?

Afrikaans title for 1973 movie “Six Million Dollar Man”?

2013 movie about Clark Kent’s coming out of the closet.

Man van Staal at DØ

Uranium absorber Liquid argon sampling ∆η x ∆φ =0.1x0.1 readout padsPseudo projective towersContained in 3 cryostats

D0 was born as a social engineering experiment by the Fermilab PAC on July 1, 1983. I met Harry at the first proto-collaboration meeting a few weeks later.

The design that evolved was basically a calorimeter –sandwiched between a muon detector and a small tracker (no magnet).

After ganging pads longitudinally into projective towers there were 50,000 readout signals, carried on about 1000 G-10 boards with Cu pad pattern etched on them, then covered with 40 MΩ/ carbon loaded epoxy serving as HV electrodes.

Long learning curve – procuring Uranium plates, Malter discharges, removing U oxide layer, developing epoxy, routing 106 signal pads on G-10 …

Advantages of U/LAr calorimetry –unit gain, stable calibration, hermetic coverage over Ω=4π, allows fine segmentation, both transverse and longitudinal,

We aimed for equal response to electrons and hadrons.

2.3 mm

2 KV

(Harry was apparently born with a beard. But watch how it progresses in color over time.)

Harry was chef de la fabrication for signal boards

An end calorimeter bare signal board

After resistive epoxy covering

The finished central calorimeter, ready to be inserted into its cryostat.

32 EM, 16 fine sampling hadronic and 16 coarse sampling hadronic modules.

(plus two comparable sized end calorimeters.)

Weld up cryostat, never to see the modules again.

(Due to subsequent DOE rules against having bare uranium at Labs, the D0 detector is now a walk-through visitors’ display. About 700 tonnes of uranium is permanently sealed up.)

Note the small hole in cryostat reserved for tracking!

Note also Harry’s beard color after completing the calorimeter construction.

First collisions in May 1992 – initial events were not things of beauty, but soon the calibrations were complete and high quality data collection began.

D0 physics initially organized into 4 physics groups:

Top quark Heavy flavor Electroweak QCD and searches *

* Initially co-led by Harry and Nick Hadley, but subsequently split into QCD (HW and J. Blazey) and New Phenomena (Nick and Andy White)

Under Harry’s leadership of QCD group, a spate of papers soon emerged. A primary early focus was on jet production.

Central jet production cross section for jets with transverse momenta up to ½ of the beam energy spans 7 orders of magnitude.

In time, Harry led us to more sophisticated measurements

Define variable χ = e∆η where ∆η is rapidity difference between 2 jets. The Rutherford XS formula, dσ/dcosθ ~ 1/sin4(θ/2) transforms to dσ/dχ = constant. NLO QCD corrections and running αS predict small deviations.

A textbook plot showing the pointlike character of partons

We had the bright idea that by measuring the ratio of (W+1 jet) to (W+0 jet) and comparing to theoretical predictions, parametrized as a function of αS, we could make a measurement of αS.

The result shown in the figure was summarized in the paper:

QCD analyses are not always so straightforward!

Physics conveners (and managers) in 1995.

By 1994, D0 was seeing spectacular events that fit the profile of the production of top quark pairs. Huge efforts were made to complete the analyses of the 8 distinct channels.

But who you gonna call to convince 500 collaborators that the analyses are correct, complete and that a discovery paper can be submitted?

Man van Staal!? …

Your comments are requested addressed to: fnald0::greenlee, fnald0::jmbutler, msuhep::weerts, fnald0::klima, fnald0::hadley fnalv::pgrannis,fnalv::mont

We would like your comments as soon as possible, by MIDDAY TOMORROW, Tuesday Feb 21 if at all possible, and failing that, by TOMORROW MIDNIGHT, Tuesday Feb 21, 1995.

The editorial Board chaired by Harry Weerts will meet Wednesday morning.

Location of Draft File: FNALD0::PRJ$ROOT227:[QCD_3.CUCKOO]PRL95A.PS With Best Regards, Mont & Paul

Harry led the newly instituted ‘Editorial Board’ to examine the analyses, and approve the paper for submission (simultaneously with CDF).

(We hid the paper draft from prying eyes in QCD project area … )

Fitted mass distribution showing background, expected top production for (a) tight cuts and (b) loose cuts

Dijet (W→ qq) vs 3-jet (W+b) effective mass distributions for (a) background; (b) expected ttbar signal; (c) data.

In 1996, Harry was elected co-spokesperson with Hugh Montgomery. By then, Run I had ended and although analyses continued, the D0 upgrade for Run II had became the major focus.

The collaboration grew to include new groups from France, Russia, Germany, UK, the Netherlands, Czech Republic, Sweden, Colombia, and Korea, benefiting from the desire of future LHC groups to get hadron collider experience.

Until 1996, D0 had operated with an unwritten constitution. Harry undertook to put a written document in place that defined rules and procedures.

New 2T superconducting magnet inside the calorimeter 4 layer barrel/disk Si microstrip vertex detector 8 layer scintillating fiber tracker Preshower detector New finer grained µ detection and triggering New firmware trigger levelThe Run I calorimeter remained (with new shorter shaping time electronics)

The D0 Upgrade

In addition to being co-spokes, in 1999 Harry succeeded Jim Christenson as upgrade co-project manager with Mike Tuts

Unusually for HEP projects, funds were tight and problems were abundant.

Silicon microstrip vertex detector

Upgrade elements

Scintillating fiber outer tracker, clear fiber and VLPC readout

Solenoid magnet, Si and scint. fiber detector, and preshower detector all fit into that small hole in the central calorimeter.

Upgrade elements

Scintillator pixel muon trigger

Upgrade elements

The completed Run II detector, assembled and ready to roll in.

In 1999, John Womersley was elected co-spokesperson. Harry continued with John until 2002.

The major event was the start of Run II in April 2001. The detector worked fine, but the Tevatron took a while to come up to speed.

The Run II detector operated until 2011 (long after Harry went on to new challenges) and collected 10 fb-1 of data (~100 x Run I), and completed nearly 400 new publications.

Harry’s mark on D0, through his role in building the Run I calorimeter, his oversight of the Run II upgrade, and his guidance of the physics program as convener and spokesperson was enormous.

2008 gathering of 8 of 10 D0 spokespersons on a boat on the Seine.

+ 2 others

Thanks, Man van Staal ! Enjoy your next adventure