These Monte Carlo events have resisted elimination by more than one cut. They may have reconstruction or simulation problems. In any case they are worrisome and deserve a close look.
updated 11-Nov-1996.
Bill reports these 18 events from the very small delta-M acoplanar jet search:
Run Event Variable that "single-cuts" " double-cuts "
----------------------------------------------------------------------
328 550 pointing tighten acop
298 5439 angle of most energetic object jet angle
588 3282 " "
168 1720 echgd/nchgd eneuhad fraction
198 2222 " "
308 1670 " "
498 1442 " "
528 7621 " "
668 6917 " "
218 1582 " NONE
198 5046 acop tighten mvis
348 2819 ewed26 jet angle
648 89 " NONE
218 9725 theta_scat jet angle
388 7437 " jet angle
538 446 " eneuhad frac
538 6239 " NONE(*)
668 7669 " NONE(*)
Notes: Theta_scat was never removed in the "single-cut" study, but
simply moved to 2 degrees
event (348, 2819) is eliminated by only one cut, ewed26. The
value of ewed26 is 1.3 GeV, while the cut is at 1.0 GeV. Other
variables barely pass the cuts: the value of acop is 158.76, while
the tightened cut is 160, for instance.
event (198,5046) has an acoplanarity of 168.75 degrees. This
is probably a good reason to keep acoplanarity at 160 degrees
rather than move it back to 165 degrees. If mvis is loosened
to 30 GeV, then this event is "single cut", although its value
of mvis is very close to 30 (29.768).
More on the four single-rejected events:
218 / 1582 Ech/Nch = 0.9786 (cut at 1)
648 / 89 Ewed = 1.3 (cut at 1.0)
538 / 6239 theta_S = 2.54 deg (cut at 3 deg)
668 / 7669 theta_S = 2.6 deg
(*) These last two events (538/6239 and 668/7669) are eliminated by the
wedge cut when Bill uses the standard angle of 30 deg rather than
26 degrees. Consequently, they are "double-eliminated."
4J
218 / 1582 Pt/Evis = 0.38 ; cut at 0.4. not double-eliminated.
Thrust = 0.852 (lowering cut costs too much efficiency)
828 / 3834 Enh/Evis=0.594, Pt/Evis=0.237. Double-cut successfully.
578 / 247 E12 = 0.44 GeV ; cut at zero
198 / 9944 Ec30 = 0.65 GeV ; cut at zero. Does not trigger.
588 / 2494 cos(theta_miss)=0.912, PT/Evis=0.266. Double-cut OK.
"A few events fail only the PT cut and have PT/Ecm > 0.0175." (The cut is PT/Ecm > 0.025.) All of these events do not trigger except the following two: 238 / 5019 PT/Ecm = 0.0198 (PT/Evis = 0.424) 558 / 2667 PT/Ecm = 0.0181 (PT/Evis = 0.445)
2JL
368 / 780 2.2 GeV muon (IDF=11), theta_S = 2 deg + epsilon.
Not double-killed.
469 / 8953 Killed by the combined (PT_lept,theta_S) cut. The electron
of 1.3 GeV fails the dE/dX requirement. This event does not
trigger.
638 / 9060 Same features as 469/8953.
858 / 5113 [4J-vh] rejected by pointing. E12 = 14 GeV
828 / 2612 [4J-high,acop-J] gamma->LCAL vertical crack and
double counting in EFLW
298 / 5439 [4J-high,acop-J] charm: D->Kenu e->crack K->interaction
388 / 313 [acop-J] rejected by E12 cut (E12 = 30 GeV)
518 / 8052 [acop-J] rejected by acopT (165.7 deg; cut at 120 deg)
A variation of his backup neutral energy cut gives one more:
408 / 5778 [2JL-low] PT/Ecm = 0.015. P_lept = 2.15 GeV muon (?)
All of these events come from the standard Monte Carlo samples.
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