slide1
Download
Skip this Video
Download Presentation
QCD Meeting October 1, 2004

Loading in 2 Seconds...

play fullscreen
1 / 13

QCD Meeting October 1, 2004 - PowerPoint PPT Presentation


  • 108 Views
  • Uploaded on

_.  Polarization Tom Devlin Rutgers/CDF. Strong polarization seen in fixed-target experiments where jet NOT observed. Is it due to the hard collision?. Is it due to fragmentation?. QCD Meeting October 1, 2004. Status and Plans. Three known contributions to dataset:

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' QCD Meeting October 1, 2004' - nona


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide1

_

 Polarization

Tom Devlin

Rutgers/CDF

Strong polarization seen

in fixed-target experiments

where jet NOT observed.

Is it due to the

hard collision?

Is it due to

fragmentation?

QCD Meeting

October 1, 2004

slide2

Status and Plans

Three known contributions to dataset:

--  Signal

-- Ks Background

-- Continuum 2-track background

MC code exists to generate first two.

Coding in progress for the third.

Plan:

Generate 20 MC of each type for each real event.

Mix three MC samples, in appropriate proportions

to produce 20 MC events for each real event.

Adjust proportions of each and assumed polarization

of MC ’s to fit data.

slide3

Old Distribution Shown Last Time

Fit with no Mass Constraint: Assume Daughters are p

Subtract  signal, Smooth Remainder (5-bins)

slide8

Huge Improvement in Signal/Noise

Extended Momentum Range

from 2-12 GeV/c to 2-20 GeV/c

Study , Ks,  Background vs.

Momentum and Flight Distance Lxy

slide9

For one bin in p and Lxy: (loose-cut ) – (tight-cut ),

(tight-cut Ks), plot both vs. M2(p)

Sum of two plots = Ks + background

Subtract from loose-cut   Number of pure 

slide11

For Each Bin in Momentum and Lxy

Evaluate Fractions of , Ks and 

slide13

Work in Progress and Planned: Fall, 2004

  •  Mass-constrained fits: 2-, 2-Ks, 1-ee.
  •  Sum of weights over solutions = 1.0 per event.
  •  Use 2 = 2(MassConstraint) - 2(NoMassConstraint)
  • Determine relative proportions of , Ks and background
  • Modify 2nd stage analysis code to mix MC samples from
  • , Ks,  in correct proportions.
  • Possibly as fit parameters with constraints.
  • See if a believable polarization analysis can be done
  • in one of the three coordinate systems.
  • If so, do polarization in the other two coordinate systems.
ad