Dear E866'rs - Here are my notes from the E866 collaboration meeting held on Dec. 1st at FNAL. Feel free to comment, correct, etc. The transparencies have been copied. I will send one copy to each institution unless otherwise requested. Thanks, Pat --------------------------------------------------------------- Pat McGaughey gave some E866 news - The new fixed target schedule shows the beginning of the run at April 1, 1996 with 4 periods of beam totaling about 18 months of beam time. The level 2 trigger meeting, held in August, recommended that Carl Gagliardi and company proceed with the trigger upgrade. Pat requested that everyone make sure they are signed up on the E866 listserver. Georgia State has asked to join the E866 collaboration. Dave Lee summarized progress on the Station 1 drift chambers - The cathode plane foils and anode wire planes have been temperature cycled to check for mechanical problems; none were found. A high rate source test showed no effects for a 0.1 coul/ cm2 integrated charge. An efficiency plateau of the prototype Y chamber reaches 100% at 1700V and is at least 150V wide. A detailed mechanical design for the station 1 Y chamber was shown, including PC board artwork. Garfield simulations of the drift field, time and pulse heights were also given. Carl Gagliardi discussed the trigger upgrade - The general scheme is to use the existing hodo disc/latch and trigger matrix system, but to replace the DC logic with custom track correlators and a master trigger OR. Two main triggers are proposed. The primary physics trigger would be a 2 out of 4 matrix coincidence of Y hodoscopes. The secondary trigger is an Xleft and Xright coincidence requiring one Y matrix. This can be used to study the efficiency of the other trigger matrices. There was also discussion of a special station 4 veto trigger that would specifically reject low Pt J/psi's from the beam dump, but not high Pt muon pairs. A detailed design for the track correlator module was shown together with timing information that demonstrates sufficient safety margin on the total trigger delay. A study of the random matrix rate was done by Pat McGaughey which demonstrates that single muons should not add excess rate to the trigger. Tom Carey gave the status of the DAQ upgrade - The current goals are to integrate the spill and event data on tape, enhance the on-line monitoring, completely integrate the transport to VME and retire the PDP. He also proposed to implement a level 3 trigger in VME using DSP's. We will replace the exabyte 8200's with 8500's offering twice the speed and density. The development host / operator console will be a sparcstation 10 class CPU with full Xwindows support. EPICS is being investigated as the control software. Modules have been purchased for the spill & event integration. GSU and ORNL have expressed interest in implementing the level 3 trigger. A detailed schedule for the various upgrades and a list of man- power was given. Pat McGaughey showed early results on beam dump dimuons - Following the discovery that the trigger for E772 accepted high mass dimuons for the dump, 18 tapes of E772 data have been reanalyzed. The resulting 400,000 events contain about 70,000 upsilons covering an Xf range of -0.4 to 0.8 and Pt of 0 to 6 GeV. The mass resolution is about 350 MeV. The Drell- Yan events have an average mass of about 8 GeV. There is almost no like sign contamination in the data. Analysis of the full set of 60 tapes is underway. E866 should be able to do even better as the new trigger will have better acceptance at large Pt. It should be possible to improve the mass resolution and possibly do an A-dependence with targets about 1 meter upstream of the dump. Joel Moss studied the angular distributions from E772 - The angular distributions of Drell-Yan are still poorly understood theoretically. Plots of theta and phi in the Collins- Soper frame were compared with data from NA10. Unfortunately, our limited acceptance in Pt and theta result in a marginal measurement. However, the beam dump data that Pat reported on previously may be a good candidate for further study. The new trigger in E866 should also provide a better data set. Doug Jansen discussed some additional physics for E866 - J/psi pairs from the beam dump may not be a good candidate for measuring the b-bbar cross section, as their rate may be insignificant compared to that of pairs from direct gluon fusion. Another worry is the rate of pairs from multiple interactions when running at high intensity. Psi and psi' production at high Pt may be a more attractive way to measure the b cross section, if we have enough acceptance. Large Pt production of upsilons is also of interest. A high statistics measurement of Drell-Yan at 5.3 GeV could provide a new limit on the branching ratio for b-> mu+ mu-. Good mass resolution would be required. Don Isenhower reported on the status of the hodoscopes - Over the summer the station 1 hodoscopes were replaced with new ones covering the full Y height of 40". There are now 32 Y counters and 24 X counters. The Y counter at station 2 was taken down and repaired. All hodoscopes are reinstalled and tested. Only one counter appears to be broken (Y4L6). Glenn Young summarized work with the proportional tubes and some experience with digital signal processors at CERN - All but one of the broken wires were repaired last summer. 2500V was applied to the planes with N2 gas without problems. DC and threshold voltage at the discriminator cards was also checked. Next is to switch to chamber gas and check out the signals. Experiment WA98 at CERN is using DSP's to zero suppress and format data from PMT's. They use a number of the MIZAR quad TI TMS320C40 boards running in parallel. They found the Mizar board to effectively be a beta test unit (lots of problems). Programming was done in C, not assembler and loaded through the JTAG interface into EEPROM. The code had to be hand tuned to optimize the speed. Eric Hawker discussed the trigger and drift chamber electronics - The two key components to the track correlator have been identified. A 64K X 4 ECL SRAM chip with 10 ns is available for between $130 to $180 per unit. An Altera programmable logic device (EPM 7032) should be able to perform as a prescaler. The chip and programming support is being ordered. During the summer almost all of the DC spare electronics were tested and repaired. A few preamplifiers still need some input transistors to be replaced, these are now on hand. Half of the discriminator cards must be fused before use. Much of the hodoscope fast logic was checked out over the summer, including the discriminators, stretchers and OR modules. Other than some dead cooling fans, few problems were found. Pat McGaughey talked about the Ansley cable situation. The old station 3 cables have been removed and new ones of 312ns are ready for installation. Station 2 cables need to be removed. There are not enough 370 ns cables to replace them. Station 1 cables have been tested, but not repaired yet. Some new cables are ready to install, but some damaged ones also need to be repaired. It was proposed to use the long (470ns) cables left over from the Si vertex detector to re-instrument station 2. If signal degradation is not a problem, they would be used as-is. Tom Carey summarized the status of the old DAQ system - The old SSD and RICH electronics and racks were removed. Power to the east wall of the counting house was restored. Unused transport system modules were removed. The PDP-11 was overhauled and exercised for several days. FN789 (a uVAX in the e866 counting house) was also repaired and is working. The transport system was also tested thoroughly. Chuck Brown talked about E866 facility issues - The E866 trailer will be installed next to the outside wall of the counting house at the same position as the one for E789. It consists of a pair of trailers joined end to end with a total length of 62 feet. Installation should be completed by the middle of March 1995. Preliminary construction plans for the LD2/LH2 targets, mechanical support structure and placement in the target cave were shown. Mike Leitch reported on the software status - John Keyser wrote a new interactive graphics package for the analysis code. It uses HIGZ to provide a colorized single event display that can be zoomed, rotated, etc. The analysis code now runs under KUIP/Motif on UNIX platforms (optional). The Hoist method of transmitting data over ethernet has also been implemented in the UNIX software, but still needs to be done on the VME end under VxWorks. The CPS parallel processor code in the analysis has been tested and is working. E866 codes are available through the E866 world-wide-web page or via anony- mous ftp to p2hp2.lanl.gov. Some open questions include : should we stay with CMZ for code management, what will our backend UNIX CPU's in the counting house be and which database system should we use? Chuck Brown discussed acceptance issues - Assuming that we must run the SM12 and SM3 magnets with the same polarity to avoid radiation problems, a number of plots of acceptance and event rates versus mass were shown. With the target at -139" a good setting for low mass acceptance is -2000, +2000, +4250A (SM0, SM12, SM3). For high mass acceptance +2000, +2750, +4250A is fine. (Note that Chuck's slides said 1000A, but he really meant 2000A for SM0). Concerning a possible target near the beam dump, a position near 0" has an acceptance almost as good as at the dump itself. Using a reasonably thin target, resolutions of the order of 20 MeV seem possible. An absorber layout consisting of only Cu and CH2 (no graphite) was shown. The leakage rate still needs to be studied with Geant. The collaboration selected Pat McGaughey to be the new spokesman for E866. The collaboration also gave it's approval for the Georgia State University group (presently Gus Petit and Xiaochun He) to join E866. They will join the DAQ group with the goal of helping to implement the level 3 trigger. The ORNL group has also agreed to take on a major role in this effort. The group discussed scheduling in light of the beam schedule - Pat showed the newest draft schedule (Dec. '94) which has the fixed target beam available on April 1, 1996. The new trigger modules will be prototyped in the spring and installed in mid-summer. An open issue is the development of the large number of new software pieces that are required. The DAQ upgrade plan is to have all new hardware on hand by early spring. The spill/event integration and hoist software will be completed by late spring. The PDP software port to VME and level 3 processor implementation will be done over the summer. System integration will take place in November. The new station 1 Y,Y' chamber will be completed in February. All chambers will be completed and installed during the during the summer. The ansley cable repair / reinstallation will be done in parallel during the summer. The LD2/LH2 target flask will be tested during the summer and installed in the late fall. Magnet mapping will be done in the fall. SM0 will be re- installed during the summer. We need to freeze the desired running currents by summer. The trailer installation will be completed in March. Jen-Chieh Peng summarized additional physics topics for E866 - For Drell-Yan physics : The nuclear dependence at small X2, large X2, large PT and XF near 1. The angular distributions in theta and phi. High statistics comparison of LD2/C/W. J/psi and Upsilon physics : A-dependence of J/psi versus psi'. A dependence of upsilon versus upsilon' and upsilon''. J/psi A-dependence for XF<0. Angular distribution for J/psi and upsilon. J/psi for XF near 1. Nuclear dependence of upsilon at large XF. J/psi pair production. Other physics : B -> mu+ mu+ upper limit, possibly triggering on 3 muons. B -> mu+mu+mu-mu- ? tau -> mu+-mu+mu- ? Finally, the group discussed the next collaboration meeting. Gus Petit volunteered to hold the next meeting in Atlanta with a tentative date of early April. -------------------------------------------------------------- Second Draft of Schedule for E866 meeting Thursday, Dec.1 at FNAL Meeting begins in the Wilson Hall 15th floor conference room in the north west corner (WH15NW) at 8:30 AM. I. Review of Major E866 Spectrometer Upgrades A. Station 1 Drift Chambers Dave Lee 8:30 - 9:00 B. Trigger System Carl Gagliardi 9:00 - 9:30 C. DAQ system Tom Carey 9:30 - 10:00 Coffee Break 10:00 - 10:30 Resume in WH15SW (southwest corner). II. New Physics A. Dimuons from the Dump Pat McGaughey 10:30 - 10:45 B. Drell-Yan Angular Distributions Joel Moss 10:45 - 11:00 C. J/psi pairs, etc. Doug Jansen 11:00 - 11:15 III. Progress Reports A. Hodoscope Modifications Don Isenhower 11:15 - 11:25 B. Prop. Tube Repairs, DSP notes Glenn Young 11:25 - 11:40 C. Drift Chamber Electronics Repair Eric Hawker 11:40 - 11:50 D. Trigger Electronics Checkout Eric/Carl 11:50 - 12:00 E. Ansley Cables CNB/PLM 12:00 - 12:10 F. PDP-11 and NEVIS Readout Repairs Tom Carey 12:10 - 12:30 Lunch Break 12:30 - 1:30 Resume in WH15SW (southwest corner). G. Facilities (Trailer, Targets, Chuck Brown 1:30 - 1:50 Counting House, Drift Chambers,etc.) H. Software Progress Mike Leitch 1:50 - 2:05 I. Acceptances, Resolutions Chuck Brown 2:05 - 2:15 J. Any others such as SM12 leakage, 2:15 - 2:30 monitoring issues, magnet mapping, etc? IV. Planning for 1995 A. Select Permanent Spokesman 2:30 - 2:45 B. New E866 Collaborators (Georgia State U.) 2:45 - 3:00 Break 3:00 - 3:15 C. Schedule for Installation and Testing 3:15 - 4:15 D. Date for Next Collaboration Meeting 4:15 - 4:30 and any other business Dinner (TBA) 6:00 ?