A new mass reconstruction technique for resonances decaying to ττ

By A. Elagin, P. Murat, A. Pranko, A. Safonov. 2010

236 citations recorded by the source corpus.

Abstract Accurate reconstruction of the mass of a resonance decaying to a pair of τ leptons is challenging because of the presence of multiple neutrinos from τ decays. The existing methods rely on either a partially reconstructed mass, which has a broad spectrum that reduces sensitivity, or the collinear approximation, which is applicable only to the relatively small fraction of events. We describe a new technique, which provides an accurate mass reconstruction of the original resonance and does not suffer from the limitations of the collinear approximation. The major improvement comes from replacing assumptions of the collinear approximation by a requirement that mutual orientations of the neutrinos and other decay products are consistent with the mass and decay kinematics of a τ lepton. This is achieved by maximizing a probability defined in the kinematically allowed phase space region. In this paper we describe the technique and illustrate its performance using Z / γ ⁎ → τ τ and H → τ τ events simulated with the realistic detector resolution. The method is also tested on a clean sample of data Z / γ ⁎ → τ τ events collected by the CDF experiment at the Tevatron. We expect that this new technique will allow for a major improvement in searches for the Higgs boson at both the LHC and the Tevatron.

Subfields: Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/ad71367712eaef042979c162f751a0082a0c7c38

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In Nuclear and High Energy Physics

Citations in the corpus

Deep Learning, Dark Knowledge, and Dark Matter (2014, unknown): “, where p is the momentum of any charged lepton or jet; • Diﬀerence in lepton azimuthal angles, ∆ φ ( + , − ); • Diﬀerence in lepton polar angles, ∆ η ( + , − ); • Angular distance between leptons, ∆ R = (∆ η ) 2 + (∆ φ ) 2 ; • Invariant mass of the two leptons, m + (cid:96) − ; • Missing mass, m MM”
Flavor violating Higgs decays (2012, methodology): “This approach is less optimized for h→ ττ than the maximum-likelihood method employed by CMS [56], but it is more model independent so that a substantial fraction of h→ τμ or h→ τe decays would pass the cuts.”
The measurement of the Higgs self-coupling at the LHC: theoretical status (2012, methodology): “In particular, the use of the Missing Mass Calculator algorithm offers very promising results [137].”
Higgs Physics at the HL-LHC and HE-LHC (2019, methodology): “One of the most important variables is the mass of the ⌧⌧ system, calculated in ATLAS with the Missing Mass Calculator [131], and in CMS with a dynamical likelihood technique named SVFit [132].”
Evidence for the Higgs-boson Yukawa coupling to tau leptons with the ATLAS detector (2015, unknown): “J H E P 0 4 ( 2 0 1 5 ) 1 1 7 [GeV]MMC ττ m 0 100 200 300 E v e n ts / 2 0 G e V 20 40 60 80 100 120 140 160 180 200 220 240 Data (125)H50 x ττ →Z +single-toptt Others τFake Uncert.”
Measurements of the Higgs boson production and decay rates and coupling strengths using pp collision data at \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\o (2015, unknown): “One of the most important input variables is the mass of the ττ system, which is quite challenging to reconstruct due to the presence of at least two neutrinos in the final state; the Missing Mass Calculator [101] is used for this purpose.”