DOI: 10.17182/hepdata.80812.v2/t8
title: "Table 8" of "A search for high-mass resonances decaying to $\tau\nu$ in $pp$ collisions at $\sqrt{s}$ = 13 TeV with the ATLAS detector"

description: Reconstruction efficiency as a function of $m_{\rm T}$ (see HepData abstract for parameterization), defined as the ratio of the number of $\tau\nu$ events remaining after applying the full selection at reconstruction-level to those remaining after applying the fiducial selection at generator-level. The efficiency is largely model independent, with an uncertainty of ~10% due to model choice.
description: CERN-LHC. A search for high-mass resonances decaying to $\tau\nu$ in $pp$ collisions at $\sqrt{s}$ = 13 TeV with the ATLAS detector.

 Units of GeV and pb are used for all data in this entry, which may be different to those used in the publication. 

 Fiducial region: 
 - No electrons or muons 
 - $p_{\rm T}$(e) &gt; 20 GeV, |$\eta$(e)| &lt; 2.47
 - $p_{\rm T}$($\mu$) &gt; 20 GeV, |$\eta$($\mu$)| &lt; 2.5
 - At least one hadronic tau decay ($\tau_{\rm had-vis}$)
 - $p_{\rm T}$($\tau_{\rm had-vis}$) &gt; 50 GeV, |$\eta$($\tau_{\rm had-vis}$)| &lt; 2.4
 - Choose $\tau_{\rm had-vis}$ with highest $p_{\rm T}$
 - $E_{\rm T}^{\rm miss}$ &gt; 150 GeV
 - 0.7 &lt; $p_{\rm T}$($\tau_{\rm had-vis}$) / $E_{\rm T}^{\rm miss}$ &lt; 1.3 
 - $\Delta\phi$($\tau_{\rm had-vis}$, $E_{\rm T}^{\rm miss}$) &gt; 2.4 rad 
 - $m_{\rm T}$($\tau_{\rm had-vis}$, $E_{\rm T}^{\rm miss}$) &gt; threshold 
 - Choose threshold in range 250-1800 GeV in 50 GeV steps

 Note: significant activity near the chosen $\tau_{\rm had-vis}$ would reduce its identification efficiency. If signals with a busy final state are considered we suggest to reject events if the scalar sum $p_{\rm T}$ of stable charged particles within $\Delta R$ = 0.4 or neutral particles within $\Delta R$ = 0.2 of the chosen $\tau_{\rm had-vis}$ is larger than a few GeV (not including pileup or decay products of the chosen $\tau_{\rm had-vis}$)
 
 These results can be reinterpreted for alternate signal models using the limits on the visible $\tau\nu$ production cross section ($\sigma_{\rm vis} = \sigma \times \mathcal{A} \times \varepsilon$) provided in Table 2. 

 Reinterpretation requires calculation of: 
 - $\sigma$: signal cross section including production and decay
 - $\mathcal{A}$: acceptance of fiducial selection at generator level
 - $\varepsilon$: reconstruction efficiency

 First, calculate the visible cross section for each $m_{\rm T}$ threshold at a single parameter-space point of the signal model is question. The parameter-space point is excluded if the visible cross section is larger than the limit at any $m_{\rm T}$ threshold. Repeat the process for all parameter-space points and models to determine the excluded regions. 

 The reconstruction efficiency is dependent on $m_{\rm T}$, and therefore on the $m_{\rm T}$ distribution of the signal model. It can be incorporated by weighting generated events by the parameterized efficiency: 
 $\varepsilon$($m_{\rm T}$ [TeV]) = 0.633 - 0.313$m_{\rm T}$ + 0.0688$m_{\rm T}^2$ - 0.00575$m_{\rm T}^3$

 For reference, the optimal $m_{\rm T}$ thresholds for the SSM and NU models are given in Table 5, the acceptance and acceptance times efficiency for the SSM model can be found in Tables 6 and 7 and the model independent reconstruction efficiency can be found in Table 8.