tamu/regina lhc tau study
DESCRIPTION
TAMU/Regina LHC Tau Study. Suggested study for tau reconstruction/ID Obtained by Abram Krislock, Alfredo Gurrola, and Paul Simeon (TAMU students); Nikolay Kolev (postdoc; Regina, Canada) Based on PYTHIA Z t h t h events with PGS4. Tau in a Small Cone (10 deg or less). t. - PowerPoint PPT PresentationTRANSCRIPT
September 20, 2006 TAMU/Regina LHC Tau Study 1
TAMU/Regina LHC Tau StudyTAMU/Regina LHC Tau StudySuggested study for tau reconstruction/ID
Obtained by Abram Krislock, Alfredo Gurrola, and Paul Simeon (TAMU students); Nikolay Kolev (postdoc; Regina, Canada)
Based on PYTHIA Z hh events with PGS4
September 20, 2006 TAMU/Regina LHC Tau Study 2
Tau in a Small Cone (10 deg or less)Tau in a Small Cone (10 deg or less)
30 deg. cone
10 deg. cone for low energy tau and smaller when higher
UE tracks are uniformly distributed in - plane.
How often are those tracks seen in the signal cone?
And isolation cone?
We show a preliminary result.
Remember a CDF-like tau signal ID
September 20, 2006 TAMU/Regina LHC Tau Study 3
UE Tracks (all UE Tracks (all ))PGS4/PYTHIA
10 deg = 175 mrad
2.8 deg = 50 mrad
RECAP: tau signal cone …
Z
UE in Z
(trac
ks; p
T > 1
GeV
) aro
und
10 deg
10 deg
The UE tracks are uniformly distributed in - plane.
The same probability of seeing the UE events in R = 0.4 (for example).
How often does the 30-deg cone see the UE tracks?
Evisible (GeV)
September 20, 2006 TAMU/Regina LHC Tau Study 4
RECAP:RECAP:RR = 0.4 Cone Size = 0.4 Cone Size
= 22.3o
= 7.4o
= 5.0o
10 deg = 175 mrad
2.8 deg = 50 mrad
= 0.0
= 2.0
September 20, 2006 TAMU/Regina LHC Tau Study 5
UE tracks(pT > 1 GeV) at = 0, 1, 2 = 0, 1, 2
How often are taus rejected because of the UE tracks?
= 0 = 1
= 2
Shrinking isolation cone???
(tr
acks
; pT >
1 G
eV) a
roun
d
= 30o
20 GeV
40 GeV
Evisible (GeV)
September 20, 2006 TAMU/Regina LHC Tau Study 6
TauTauAcceptance …Acceptance …
= 1
= 0
~96% w/o UE tracks
Fraction of tau’s with a) Ntrack = 0 or 1 (pT>1 GeV)
in the signal (shrinking) cone;
b) Ntrack = 0 (pT>1 GeV)in the isolation (shrinking) cone
Evisible (GeV)
~60% w UE tracks40 GeV
= 2
20 GeV
September 20, 2006 TAMU/Regina LHC Tau Study 7
30 GeV Jet at 30 GeV Jet at = 0 = 0
=22.5o=22.5o
= -0.55= 120o
= 0.55= 60o
= 0= 90o
= 30o
= 0.4= 67.5o
= -0.4= 122.5o
shrinking(signal) shrinking(signal) = 2o
for 100 GeV Rjet= 0.4
shrinking(signal) shrinking(signal) = 10o
for 30 GeV
Illustrativepurpose
September 20, 2006 TAMU/Regina LHC Tau Study 8
30 GeV Jet at 30 GeV Jet at = 2 = 2
=5.0o=7.4o
= 1.51= 25o
= 3.13= 5o
= 2.4= 10.4o
= 1.6= 22.8o
= 2= 15.4o
shrinking(signal) shrinking(signal) = 10o
for 30 GeV
shrinking(signal) shrinking(signal) = 2o
for 100 GeV Rjet= 0.4
Illustrativepurpose
September 20, 2006 TAMU/Regina LHC Tau Study 9
SummarySummary Proposal: Shrinking isolation cone(?) to minimize the
UE effect.