Progress report on sbottom and gluino reconstruction Massimiliano Chiorboli Universita and INFN Catania

Progress report on sbottom and Progress report on sbottom and gluino reconstructiongluino reconstruction

Progress report on sbottom and Progress report on sbottom and gluino reconstructiongluino reconstruction

Massimiliano Chiorboli

Universita’ and INFN Catania

8 Mar 2002CMS Week - Physics Meeting Massimiliano Chiorboli

99.610 = LSP

186.01±145.8lR

379.72±211.4lL

186.820549qR

358.830570qL

379.140549.7bR

600.5tR522.5bL

412.5tL643.3g

Proposed Post-LEP Benchmarks for Supersymmetry Proposed Post-LEP Benchmarks for Supersymmetry (hep-ph/0106204)(hep-ph/0106204)Proposed Post-LEP Benchmarks for Supersymmetry Proposed Post-LEP Benchmarks for Supersymmetry (hep-ph/0106204)(hep-ph/0106204)

pb 41.41TOTSUSY


Decay chainDecay chainDecay chainDecay chain

p

p

g~

b~

b

b

01

~

02

~ ~

0A

)( sign

10β tan

100m

250m

0

0

21

bb~

g~ pp

b~02

01

~

(15% bL, 10% bR)

(35 % bL, 22% bR)

(0.2 %)

01

~ ~

(60 %)

Event final state:

• 2 high pt isolated leptons OS

• 2 high pt b jets

• missing Et


Event productionEvent productionEvent productionEvent production

2 isolated leptons, pT>15 GeV, ||<2.4

2 b-jets, pT>20 GeV, ||<2

• PYTHIA 6.152• CMSJET 4.801

SM bkg: tt, Z+jet, W+jet, ZZ, WW, ZW


First step: First step: 2200 l l++ll- - 11

00First step: First step: 2200 l l++ll- - 11

00

02

~ 01

~

~p

p

g~

b~

b

b

01

~

02

~ ~

GeV 85.32 M

)M)(MM(MM

2

χ

222

χmax01

02

~

~~~~

GeV 1.64 86.00 Mmax

Fit result:

)μM(μ )eM(e -

)μM(e -)μM(e - )μM(μ )eM(e -- Etmiss > 50 GeV

10 fb-1


Sbottom reconstructionSbottom reconstructionSbottom reconstructionSbottom reconstruction

p

p

g~

b~

b

b

01

~

02

~ ~

Assuming M(10)

known!

p

M

M1p

01

02

~

~

GeV 92 M GeV 75


Sbottom reconstructionSbottom reconstructionSbottom reconstructionSbottom reconstruction

Etmiss > 50 GeV Et

miss > 100 GeV Etmiss > 150 GeV


Sbottom massSbottom massSbottom massSbottom mass

55.8

GeV 8.1516.4b)~M( 02

Result of fit:

GeV 7.549)b~

M(

GeV 5.522)b~

M(

R

L

Generated masses:


Gluino reconstructionGluino reconstructionGluino reconstructionGluino reconstruction

p

p

g~

b~

b

b

01

~

02

~ ~

b)b~

( angle

Etmiss > 150 GeV


Gluino massGluino massGluino massGluino mass

9.54σ

GeV 7.2631.8bb)χ~M( 02

Result of fit:

GeV 643.3)gM( ~Generated mass:


Combinatorial suppressionCombinatorial suppressionCombinatorial suppressionCombinatorial suppression

tt~ g~ 1

t~ b,~ (2.7%), b~ 0221

(8%)

%) (3.5t ~ b~ 11

%) (1W t~ b~ 11

t~ b,~ (2.7%), b~ 0221

%) (1.6t ~ b~ 12

%) (1.2W t~ b~ 12

t~ b,~ (2.7%), b~ 0221

GeV 60 t)t~M(-)g~M(

GeV 200 b)~M(-)t~M(

GeV 170 t)~M(-)b~

M(

GeV 20 W)t~M(-)b~

M( GeV 330 b)~M(-)b

~M( 0

2



Eb-jet 1 > 250 GeV

Sbottom Gluino



Sbottom Gluino


Sbottom massSbottom massSbottom massSbottom mass

68.8

GeV 7.7515.9b)~M( 02

Result of fit:

GeV 7.549)b~

M(

GeV 5.522)b~

M(

R

L

Generated masses:


Gluino massGluino massGluino massGluino mass


9.04σ

GeV 8.3639.3bb)χ~M( 02

Result of fit:


Dependence on M(ll)Dependence on M(ll)Dependence on M(ll)Dependence on M(ll)

GeV 92 M GeV 75 GeV 92 M GeV 60

GeV 92 M GeV 80

Sbottom

Gluino


Dependence on M(Dependence on M())Dependence on M(Dependence on M())

M(10) true

M(10) = M(ll)

M(10) = M edge

p2p

M

M1p

01

02

~

~


estimationestimation estimationestimation

doesn’t depend on M(10) !

)b~

M(-)g~M(

GeV 30)~M( 01

)bM(-)gM(~~ )bM(-)gM(~~



6.32σ

GeV 6.387.5b)χ~M(bb)χ~M( 02

02

Result of fit:

)bM(-)gM(~~ )bM(-)gM(~~

GeV 6.93)b~

M(-)g~M(

GeV 8.120)b~

M(-)g~M(

R

L

Generated values:


With 60 fbWith 60 fb-1-1With 60 fbWith 60 fb-1-1

60 fb-1

Sbottom


cos (b2-sb) cos(b1-ll)

cos(b2-ll) cos(b1-b2)


Sbottom(s) with 60 fbSbottom(s) with 60 fb-1-1Sbottom(s) with 60 fbSbottom(s) with 60 fb-1-1

2.25

GeV 5.45.824b)~M( 02

Result of fit:

2.31

GeV 10.04.555b)~M( 02

Etmiss > 150 GeV

Eb-jet 1 > 250 GeV

cos (b2-sb)>0.

cos(b1-ll)>0.

cos(b2-ll)>0.

cos(b1-b2)>0.

GeV 7.549)b~

M(

GeV 5.522)b~

M(

R

L

Generated masses:


Gluino with 60 fbGluino with 60 fb-1-1Gluino with 60 fbGluino with 60 fb-1-1

2.84σ

GeV 4.2633.5bb)χ~M( 02

Result of fit:60 fb-1



with 60 fbwith 60 fb-1-1 with 60 fbwith 60 fb-1-1

60 fb-1

0.37σ

GeV 3.50.99b)χ~M(bb)χ~M( 02

02

Result of fit:

)bM(-)gM(~~ )bM(-)gM(~~

GeV 6.93)b~

M(-)g~M(

GeV 8.120)b~

M(-)g~M(

R

L

Generated values:


152.510 = LSP

294.51±193.4lR

546.12±299.6lL

294.820780qR

532.430814qL

545.340771.3bR

800.8tR723.0bL

589.4tL919.8g

Point GPoint GPoint GPoint G

pb 6.00TOTSUSY


tt~ g~ 1

t~ b,~ %), (2.7 %) (8.5 b~ 0221

(16%) (8 %)

Decay chainDecay chainDecay chainDecay chain

bb~

g~ pp

b~02

(16% bL, 10% bR)

(15 % bL, 28% bR)

01

~ ~

(8 %) (60 %)

%) (3.5 %) (7t ~ b~ 11

(1%) %) (3W t~ b~ 11

%) (1.6 %) (2.6t ~ b~ 12

%) (1.2 %) (3.2W t~ b~ 12


Dilepton EdgeDilepton EdgeDilepton EdgeDilepton Edge

60 fb-1

)μM(μ )eM(e -

E(ll) > 160 GeV

SUSY only l

slepton l



Etmiss > 100 GeVEt

miss > 50 GeV Etmiss > 150 GeV

E(ll) > 160 GeV



)μM(μ )eM(e - )μM(e -)μM(e - )μM(μ )eM(e --

E(ll) > 160 GeV Etmiss > 200 GeV


Sbottom and gluinoSbottom and gluinoSbottom and gluinoSbottom and gluino

Etmiss > 200 GeV

Sbottom Gluino



Eb-jet 1 > 300 GeV


SM suppressionSM suppressionSM suppressionSM suppression

(ll-Etmiss)

(ll) (bb)


Sbottom and gluinoSbottom and gluinoSbottom and gluinoSbottom and gluino

Etmiss > 200 GeV

Eb-jet 1 > 300 GeV

(ll-Etmiss) > -0.8

(ll) > -0.6

(bb) > -0.7


Sbottom peakSbottom peakSbottom peakSbottom peak

6.82

GeV 8.743b)~M( 02

Result of fit:

GeV 3.771)b~

M(

GeV 0.723)b~

M(

R

L

Generated masses:


Guino peakGuino peakGuino peakGuino peak

7.31σ

GeV 1.909bb)χ~M( 02

Result of fit:

GeV 8.199)g~M(

Generated mass:



This needs better understanding of the SM bkg behaviour!

27.9σ

GeV 5.7168.1b)χ~M(bb)χ~M( 02

02

Result of fit:

)bM(-)gM(~~ )bM(-)gM(~~

GeV 5.148)b~

M(-)g~M(

GeV 8.196)b~

M(-)g~M(

R

L

Generated values:


Point G with 150 fbPoint G with 150 fb-1-1Point G with 150 fbPoint G with 150 fb-1-1

No Pile Up!


Sbottom and gluino with 150 fbSbottom and gluino with 150 fb-1-1Sbottom and gluino with 150 fbSbottom and gluino with 150 fb-1-1

Sbottom Gluino

M(g)-M(b)


ConclusionsConclusionsConclusionsConclusions

Point G, with 60 fb-1

• Sbottom and gluino seem to be visible

• estimation of M(l+l-)max

• sbottom reconstruction with Resol. ~ 10 %, but 2 sbottoms not resolved

• gluino reconstruction with Resol. < 10 %

• M(g) - M(b) estimation, independent of M(10), with Err ~ 4 %

Point B, with 10 fb-1

~2~

2~

2~

2~ M)MM)(MM( 0

102

• Maybe we can separate the 2 sbottoms

Point B, with 60 fb-1


Eb-jet 1

PTb-jet 1

b-jet 1

Eb-jet 2

PTb-jet 2

b-jet 2

Documents

Progress report on sbottom and gluino reconstruction Massimiliano Chiorboli Universita and INFN Catania