l event selection l method l combination l summary and conclusion color reconnection analysis for...

Event selection

Method

Combination

Summary and conclusion

Color reconnection analysisfor the summer conference

2001 in Budapest

Thomas Ziegler, Johannes Gutenberg Universität, Mainz W meeting 13. Juni 2001 1

Thomas Ziegler, Johannes Gutenberg Universität, Mainz W meeting 13. Juni 2001 2

Event selections

L3 like selection (very restrictive)

More global selection (effectively W mass selection)cut on neural net output at 0.3

Thomas Ziegler, Johannes Gutenberg Universität, Mainz W meeting 13. Juni 2001 3

particle flow method

use projection into 4 planes for both selections!

•particle flow (using all charged/neutral objects)•charged particle flow (using charged tracks only)•energy flow (using all charged/neutral objects)•charged energy flow (using charged tracks only)

Thomas Ziegler, Johannes Gutenberg Universität, Mainz W meeting 13. Juni 2001 4

Thomas Ziegler, Johannes Gutenberg Universität, Mainz W meeting 13. Juni 2001 5

Thomas Ziegler, Johannes Gutenberg Universität, Mainz W meeting 13. Juni 2001 6

rescaling of angles:

Thomas Ziegler, Johannes Gutenberg Universität, Mainz W meeting 13. Juni 2001 7

rescaling of angles:

Thomas Ziegler, Johannes Gutenberg Universität, Mainz W meeting 13. Juni 2001 8

Charged particle flow

L3 selection NN selection

Thomas Ziegler, Johannes Gutenberg Universität, Mainz W meeting 13. Juni 2001 9

energy flow

L3 selection NN selection

Thomas Ziegler, Johannes Gutenberg Universität, Mainz W meeting 13. Juni 2001 10

normal particle flow

L3 selection NN selection

Thomas Ziegler, Johannes Gutenberg Universität, Mainz W meeting 13. Juni 2001 11

The Rathsman model

Thomas Ziegler, Johannes Gutenberg Universität, Mainz W meeting 13. Juni 2001 12

Thomas Ziegler, Johannes Gutenberg Universität, Mainz W meeting 13. Juni 2001 13

Thomas Ziegler, Johannes Gutenberg Universität, Mainz W meeting 13. Juni 2001 14

Combination of results

2 2

L3 selectionparticle flow

NN selectionparticle flow

Rn2.6 1-limit 6-7 Rn3.5 1-limit 12-13Ki Ki

Thomas Ziegler, Johannes Gutenberg Universität, Mainz W meeting 13. Juni 2001 15

Some numbers

L3 sel S(Rn) Rn 1 limit

pflow 4.2 2.6 6.8

eflow 2.9 1.6 7.6

ch. pflow 3.5 8.0 80.0

ch. eflow 2.2 1.5 9.2

NN sel

pflow 5.0 3.5 12.0

eflow 3.6 3.5 50.0

ch. pflow 4.6 7.0 80.0

ch. eflow 2.8 2.3 15.0

Thomas Ziegler, Johannes Gutenberg Universität, Mainz W meeting 13. Juni 2001 16

Systematics

already included:- difference JETSET – HERWIG- difference BE reference – BE inside W only- MC statistics

Still to be done- vary BKG by +/- 1

Thomas Ziegler, Johannes Gutenberg Universität, Mainz W meeting 13. Juni 2001 17

LEP combination

want to perform it for 189 GeV before summer conference!

DLO have L3 selection, pflow in 4 planes,with charged tracks only

considered systematics:as shown before, but without difference JETSET-HERWIG

Thomas Ziegler, Johannes Gutenberg Universität, Mainz W meeting 13. Juni 2001 18

What still has to be done

Produce all Rn values for all models (at 189 GeV)( Rathsman, Ar, Ar2, SKII, Hw, Hw cr)(just have to make the list)

Calculate 2 for all models (at 189 GeV)

Systematics: vary BKG by +/- 1 uncertainty

Thomas Ziegler, Johannes Gutenberg Universität, Mainz W meeting 13. Juni 2001 19

What to show for the conference

Use normal particle flow with W-mass selection in 4 planes (as it has highest sensitivity)

L3 selection in 4 planes can/should be shown as well as comparison to DLO results