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Title: Testing invisible momentum ansatze in missing energy events at the LHC

Journal Article · · Journal of High Energy Physics (Online)
 [1];  [2];  [3];  [3]
  1. European Organization for Nuclear Research (CERN), Geneva (Switzerland). Theory Division
  2. Univ. of Florida, Gainesville, FL (United States). Physics Dept.
  3. European Organization for Nuclear Research (CERN), Geneva (Switzerland)

We consider SUSY-like events with two decay chains, each terminating in an invisible particle, whose true energy and momentum are not measured in the detector. Nevertheless, a useful educated guess about the invisible momenta can still be obtained by optimizing a suitable invariant mass function. We review and contrast several proposals in the literature for such ansatze: four versions of the M T 2-assisted on-shell reconstruction (MAOS), as well as several variants of the on-shell constrained M 2 variables. We compare the performance of these methods with regards to the mass determination of a new particle resonance along the decay chain from the peak of the reconstructed invariant mass distribution. For concreteness, we consider the event topology of dilepton tt¯ events and study each of the three possible subsystems, in both a tt¯ and a SUSY example. We find that the M 2 variables generally provide sharper peaks and therefore better ansatze for the invisible momenta. We show that the performance can be further improved by preselecting events near the kinematic endpoint of the corresponding variable from which the momentum ansatz originates.

Research Organization:
Univ. of Florida, Gainesville, FL (United States); European Organization for Nuclear Research (CERN), Geneva (Switzerland)
Sponsoring Organization:
USDOE Office of Science (SC), High Energy Physics (HEP)
Grant/Contract Number:
SC0010296
OSTI ID:
1424608
Journal Information:
Journal of High Energy Physics (Online), Vol. 2017, Issue 8; ISSN 1029-8479
Publisher:
Springer BerlinCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 10 works
Citation information provided by
Web of Science

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Portraying double Higgs at the Large Hadron Collider journal September 2019
Kinematic focus point method for particle mass measurements in missing energy events journal October 2019
Dreaming awake: disentangling the underlying physics in case of a SUSY-like discovery at the LHC journal September 2019
Portraying Double Higgs at the Large Hadron Collider conference January 2021

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