1. CMS Luminosity Status Report
Gregory Snow and Marco Bozzo
Brief history
Goals and techniques discussed in Luminosity Working Group
Discussions this CMS week
Suggested documentation to track development
Suggested outline for first CMS note
CMS Luminosity Report
March 8, G. Snow and M. Bozzo

2. Brief History Workshop on CMS/TOTEM Integration and the Luminosity
Measurement at CMS, November 18-19, 1999
(Yellow Book)
Luminosity Working Group meetings: 22/6/2000, 14/7/2000,
25/9/2000, 18/12/2000
All slides available at EDMS/TOTEM/TOTEM General/Luminosity
Luminosity strategy summarized in 2-page note to
CMS/LHCC, 25/9/2000
Luminosity report at CMS TCM, 2/4/2001
CMS Luminosity Report
March 8, G. Snow and M. Bozzo

3. Calibrate during TOTEM tot measurement,
Goals and Techniques
Aim for < 5% uncertainty in luminosity measurement
Best to have redundant, cross-checkable measurements
Bunch-by-bunch measurement best
Counting “Zeros” technique based on HF tower occupancy
Count vertices using fast inner track reconstruction
Monitor physics processes: Inclusive W or Z most popular
Accelerator: Instrument TAS and/or TAN absorbers 
Calibrate during TOTEM tot measurement,
Special runs needed
CMS Luminosity Report
March 8, G. Snow and M. Bozzo

4. Discussions this CMS Week
Request from A. Ball and Steering Committee
Write up luminosity status (CMS note) by June CMS week
Counting zeros technique using HF
HF group meeting: Rely on GCT for occupancy histograms, i.e. do NOT
read out HF last-dynode signals to independent scaler system
Specifications to be provided to Bristol group for GCT prototype design
Memory requirements for occupancy histograms bunch by bunch
Acceptable sampling/histogram filling rate for good statistics
in short time
Counting vertices technique
A. Starodumov will write up previous feasibility study
Fast inner track algorithm evolving – will describe
Accelerator luminosity measurement (D. Brandt, A. Verdier)
Front of TAN, not TAS, absorber will be instrumented
Two competing detector techniques not yet decided
CMS Luminosity Report
March 8, G. Snow and M. Bozzo

5. TOTEM Directions
TOTEM has decided to have its read-out electronics synchronized
to the 40 MHz machine clock
The evaluation of the time necessary for different trigger scenarios
are as detailed as possible given the present knowledge of the machine
installation in the tunnel (detailed cable routing needed)
See M. Oriunno talk
The TOTEM detector design guarantees the precision (1-2%) for the
tot measurement foreseen in the Technical Proposal
Concerns about present vacuum chamber configuration degrading
the measurements for || > 5.
CMS Luminosity Report
March 8, G. Snow and M. Bozzo

6. Documentation to Track Development
Conceptual Design of Luminosity Measurement
CMS/TOTEM Note #1
Strategy, special run requirements
Summary of Working Group “proof of principles”
Target date for completion: June 2002 CMS week
Technical Implementation of Luminosity Measurement
CMS/TOTEM Note #2
Details of monitoring read-out electronics
Integration with DCS and calibration environments
Online information available, information exchange with LHC machine
Luminosity database for offline physics analysis
Target date: End of 2002, early 2003
Elements in TOTEM TDR
CMS Luminosity Report
March 8, G. Snow and M. Bozzo

7. Outline of June 2002 CMS note
Overview and Strategy
G. Snow and M. Bozzo
Role of TOTEM in the CMS Luminosity Measurement
M. Bozzo + other TOTEM
Counting zeros technique using HF
G. Snow, J. Freeman, D. Cussans
Counting vertices technique
A. Starodumov, R. Castaldi
Monitoring via Physics Processes
G. Snow + volunteer(s)
Outlook, future plans, milestones
G. Snow, M. Bozzo
Target length
15 pages
Detailed outline, responsibilities
March 22
Rough draft of all sections
May 17
Final draft of all sections
May 31
Integration
June 7
CMS Luminosity Report
March 8, G. Snow and M. Bozzo

8. Luminosity Monitoring via W  lepton counting
CMS Luminosity Report
March 8, G. Snow and M. Bozzo