Dib Effective mass

1
Di-b Effective mass

• Nice Higgs Peak! But there's a lot of
  background...
• Choose our Higgs mass window to be 100GeV lt Mbb
  lt 120GeV
• Then let's see what our observable, the Higgs
  Jet effective mass, looks like.

2
HiggsJet 2nd Effective Mass

• This is the 2nd leading effective mass
  distribution.
• The endpoint may be shifting a little... it sure
  looks better than the ZJet case, at least.

All M0 471 GeV M1/2 400 GeV M1/2 480
GeV M1/2 520 GeV
3
Higgs Sideband Subtraction

• Nice Higgs Peak! But there's a lot of
  background...
• So, let's subtract the sidebands.
• For our Higgs plus jet distribution, we make the
  peak range HiggsJet effective mass distribution
  and subtract half of the sideband ranges
  HiggsJet effective mass distribution.
• Sidebands may be too close to signal...

4
HiggsJet 2nd Effective Mass - Sideband Subtracted

• This is still the 2nd leading effective mass
  distribution, but the sidebands have been
  subtracted.
• Still showing an endpoint shift, but the number
  of counts is quite low...
• Difficult to compare the shapes, need to rebin.

All M0 471 GeV M1/2 400 GeV M1/2 480
GeV M1/2 520 GeV
5
Higgs Sideband Subtraction Let's try that
again....

• Nice Higgs Peak! But there's a lot of
  background...
• So, let's subtract the sidebands.
• For our Higgs plus jet distribution, we make the
  peak range HiggsJet effective mass distribution
  and subtract half of the sideband ranges
  HiggsJet effective mass distribution.
• May need to fit the background shape...

6
HiggsJet 2nd Effective Mass - Sideband Subtracted

• This is still the 2nd leading effective mass
  distribution, but the sidebands have been
  subtracted.
• Still showing an endpoint shift, but the number
  of counts is quite low...
• Difficult to compare the shapes, need to rebin.

All M0 471 GeV M1/2 400 GeV M1/2 480
GeV M1/2 520 GeV
7
HiggsJet 2nd Effective Mass - Sideband
Subtracted Rebinned

• This is still the 2nd leading effective mass
  distribution, but the sidebands have been
  subtracted.
• Still showing an endpoint shift, but the number
  of counts is quite low...
• Bins are wider now. We can clearly see the shapes.

All M0 471 GeV M1/2 400 GeV M1/2 480
GeV M1/2 520 GeV
8
HiggsJet 2nd Effective Mass - What Got
Subtracted?

• This plot shows what got subtracted. This is the
  signal plot before subtractions, with the (½)
  sideband distribution plotted on top.
• We were hoping that the sideband distribution
  would look more like background (ie pushed to the
  left.)?

M0 471 GeV M1/2 400 GeV
9
HiggsJet 2nd Effective Mass - What Got
Subtracted?

• This plot shows what got subtracted. This is the
  signal plot before subtractions, with the (½)
  sideband distribution plotted on top.
• We were hoping that the sideband distribution
  would look more like background (ie pushed to the
  left.)?

M0 471 GeV M1/2 480 GeV
10
HiggsJet 2nd Effective Mass - What Got
Subtracted?

• This plot shows what got subtracted. This is the
  signal plot before subtractions, with the (½)
  sideband distribution plotted on top.
• We were hoping that the sideband distribution
  would look more like background (ie pushed to the
  left.)?

M0 471 GeV M1/2 520 GeV
11
b Tagging Efficiency Reply from John Conway...
looks sour...

• Shown in this plot is the efficiency of b tagging
  in PGS4.
• John Conway was very careful to point out that
  this isn't the efficiency of ALL b's, but only
  the efficiency of taggable b's.
• Taggable b's have PT gt 20 GeV, and within the
  tracking volume.
• The plot shows the efficiency of tight tags.

Notice!! 35 - 40
Fake b's!!
12
Higgs Sideband Subtraction Aaaand One More
Time....

• Let's try a different method of subtracting the
  sidebands...
• Same idea as before, Signal region minus
  sidebands.
• However...

13
Higgs Sideband Subtraction Aaaand One More
Time....

• Let's try a different method of subtracting the
  sidebands...
• Same idea as before, Signal region minus
  sidebands.
• However... This time subtract the sidebands based
  on the shape of the background.

M1/2 400 GeV
14
Higgs Sideband Subtraction Aaaand One More
Time....

• Let's try a different method of subtracting the
  sidebands...
• Same idea as before, Signal region minus
  sidebands.
• However... This time subtract the sidebands based
  on the shape of the background.

M1/2 480 GeV
15
Higgs Sideband Subtraction Aaaand One More
Time....

• Let's try a different method of subtracting the
  sidebands...
• Same idea as before, Signal region minus
  sidebands.
• However... This time subtract the sidebands based
  on the shape of the background.

M1/2 520 GeV
16
HiggsJet 2nd Effective Mass - Sideband Subtracted

• This is still the 2nd leading effective mass
  distribution, but the sidebands have been
  subtracted, and Properly this time.
• Not any shape difference of course.

All M0 471 GeV M1/2 400 GeV M1/2 480
GeV M1/2 520 GeV
17
HiggsJet 2nd Effective Mass - Sideband
Subtracted Rebinned

• This is still the 2nd leading effective mass
  distribution, but the sidebands have been
  subtracted, and Properly this time.
• Not any shape difference of course.

All M0 471 GeV M1/2 400 GeV M1/2 480
GeV M1/2 520 GeV
18
HiggsJet 2nd Effective Mass - Ratio With
Endpoint

• This 2nd leading effective mass over the endpoint
  from an eyeball fit. (i had great difficulty
  believing the linear fits...)?
• The proper sideband subtraction has been
  performed, but no area normalization yet.
• Let's see the shape comparison...

All M0 471 GeV M1/2 400 GeV M1/2 480
GeV M1/2 520 GeV
19
HiggsJet 2nd Effective Mass - Ratio With
Endpoint

• This 2nd leading effective mass over the
  theoretical endpoint.
• The proper sideband subtraction has been
  performed, but no area normalization yet.
• Let's see the shape comparison...

All M0 471 GeV M1/2 400 GeV M1/2 480
GeV M1/2 520 GeV
20
HiggsJet 2nd Effective Mass - Ratio With
Endpoint

• This 2nd leading effective mass over the endpoint
  from an eyeball fit.
• No Sideband Subtraction!
• Do the shapes look better without the Sideband
  Subtraction?

All M0 471 GeV M1/2 400 GeV M1/2 480
GeV M1/2 520 GeV
21
HiggsJet 2nd Effective Mass - Ratio With
Endpoint

• This 2nd leading effective mass over the
  theoretical endpoint.
• No Sideband Subtraction!
• Do the shapes look better without the Sideband
  Subtraction?

All M0 471 GeV M1/2 400 GeV M1/2 480
GeV M1/2 520 GeV
22
HiggsJet 2nd Effective Mass - Ratio With
Endpoint

• This 2nd leading effective mass over the endpoint
  from an eyeball fit. (i had great difficulty
  believing the linear fits...)?
• The proper sideband subtraction has been
  performed, and area normalization too.
• Let's see the shape comparison...

All M0 471 GeV M1/2 400 GeV M1/2 480
GeV M1/2 520 GeV
23
HiggsJet 2nd Effective Mass - Ratio With
Endpoint

• This 2nd leading effective mass over the endpoint
  from an eyeball fit. (i had great difficulty
  believing the linear fits...)?
• The proper sideband subtraction has been
  performed, and area normalization too.
• Let's see the shape comparison...

All M0 471 GeV M1/2 400 GeV M1/2 480
GeV M1/2 520 GeV
Distinct difference in shape... worrying?
24
HiggsJet 2nd Effective Mass - Ratio With
Endpoint

• This 2nd leading effective mass over the
  theoretical endpoint.
• The proper sideband subtraction has been
  performed, and area normalization too.
• Let's see the shape comparison...

All M0 471 GeV M1/2 400 GeV M1/2 480
GeV M1/2 520 GeV
25
Abram's Questions and Comments...

• Even without the Sideband Subtraction, we see a
  shifting endpoint. Also, the last couple of
  plots seem to show better shape agreement than
  the Sideband Subtracted plots.
• Supposing that we fit the whole shape, is a
  Sideband Subtraction really necessary?
• However, it seems we may not resolve the
  difference between the endpoints of M1/2480GeV
  and M1/2520GeV. Theoretically, they are 871GeV
  and 928GeV. gtgt 6 error.