CMS-PAS-SUS-21-001

CMS-PAS-SUS-21-001
Search for direct pair production of supersymmetric partners to the $\tau$ lepton in the all-hadronic final state at $\sqrt{s}=$ 13 TeV
CMS Collaboration
July 2021

Abstract: A search for the direct production of a pair of $\tau$ sleptons in proton-proton collisions at a center-of-mass energy of 13 TeV is presented. The search is carried out in events with two $\tau$ leptons, each decaying to one or more hadrons and a neutrino. In addition to scenarios in which the $\tau$ sleptons decay promptly, the search also addresses scenarios in which the $\tau$ sleptons have macroscopic lifetimes, giving rise to displaced $\tau$ leptons. The data were collected with the CMS detector from 2016 to 2018, and correspond to an integrated luminosity of 137 fb $^{-1}$ . No significant excess is seen in the observed event counts with respect to the standard model background expectation. Limits on pair production of both promptly decaying and long-lived $\tau$ sleptons are obtained in the framework of simplified models in which the $\tau$ slepton decays to a $\tau$ lepton and the lightest supersymmetric particle (LSP), which is assumed to be stable. In the case of purely left-handed $\tau$ slepton pair production, with a prompt decay to a $\tau$ lepton and a nearly massless LSP, $\tau$ slepton masses between 115 and 340 GeV are excluded. In a scenario with macroscopic $\tau$ slepton decay lengths corresponding to $c\tau_{0}=$ 0.1 mm, $\tau$ slepton masses between 150 and 220 GeV are excluded for the case that the LSP is nearly massless.
Links: CDS record (PDF) ; CADI line (restricted) ; These preliminary results are superseded in this paper, Submitted to PRD. The superseded preliminary plots can be found here.

Figures & Tables	Summary	References	CMS Publications

Figures
png pdf	Figure 1: Diagram for direct $\tau$ pair production, followed by decay of each $\tau$ to a $\tau$ lepton and a $\tilde{\chi}^0_1$ .
png pdf	Figure 2: Event counts and predicted yields in each SR for the SM background before (upper) and after (lower) a maximum-likelihood fit to the data. The yields expected for 3 benchmark models of left-handed $\tau$ pair production assuming prompt $\tau$ decays, and one model of long-lived $\tau$ pair production in the maximally-mixed scenario are overlaid. The numbers in parentheses correspond to the masses of the $\tau$ and LSP in units of GeV for the different signal models. The first 29 bins correspond to the prompt SRs, while bins 30 and 31 correspond to the displaced SRs, as labelled in Table 1.
png pdf	Figure 2-a: Event counts and predicted yields in each SR for the SM background before (upper) and after (lower) a maximum-likelihood fit to the data. The yields expected for 3 benchmark models of left-handed $\tau$ pair production assuming prompt $\tau$ decays, and one model of long-lived $\tau$ pair production in the maximally-mixed scenario are overlaid. The numbers in parentheses correspond to the masses of the $\tau$ and LSP in units of GeV for the different signal models. The first 29 bins correspond to the prompt SRs, while bins 30 and 31 correspond to the displaced SRs, as labelled in Table 1.
png pdf	Figure 2-b: Event counts and predicted yields in each SR for the SM background before (upper) and after (lower) a maximum-likelihood fit to the data. The yields expected for 3 benchmark models of left-handed $\tau$ pair production assuming prompt $\tau$ decays, and one model of long-lived $\tau$ pair production in the maximally-mixed scenario are overlaid. The numbers in parentheses correspond to the masses of the $\tau$ and LSP in units of GeV for the different signal models. The first 29 bins correspond to the prompt SRs, while bins 30 and 31 correspond to the displaced SRs, as labelled in Table 1.
png pdf	Figure 3: Expected and observed 95% CL cross section upper limits for the combined 2016, 2017, and 2018 datasets as a function of $\tau$ mass in the degenerate $\tau$ scenario for $\tilde{\chi}^0_1$ masses of 1, 10, 20, and 50 GeV (upper left to lower right).
png pdf	Figure 3-a: Expected and observed 95% CL cross section upper limits for the combined 2016, 2017, and 2018 datasets as a function of $\tau$ mass in the degenerate $\tau$ scenario for $\tilde{\chi}^0_1$ masses of 1, 10, 20, and 50 GeV (upper left to lower right).
png pdf	Figure 3-b: Expected and observed 95% CL cross section upper limits for the combined 2016, 2017, and 2018 datasets as a function of $\tau$ mass in the degenerate $\tau$ scenario for $\tilde{\chi}^0_1$ masses of 1, 10, 20, and 50 GeV (upper left to lower right).
png pdf	Figure 3-c: Expected and observed 95% CL cross section upper limits for the combined 2016, 2017, and 2018 datasets as a function of $\tau$ mass in the degenerate $\tau$ scenario for $\tilde{\chi}^0_1$ masses of 1, 10, 20, and 50 GeV (upper left to lower right).
png pdf	Figure 3-d: Expected and observed 95% CL cross section upper limits for the combined 2016, 2017, and 2018 datasets as a function of $\tau$ mass in the degenerate $\tau$ scenario for $\tilde{\chi}^0_1$ masses of 1, 10, 20, and 50 GeV (upper left to lower right).
png pdf	Figure 4: Expected and observed 95% CL cross section upper limits for the combined 2016, 2017, and 2018 datasets as a function of $\tau$ mass in the purely left-handed $\tau$ scenario for $\tilde{\chi}^0_1$ masses of 1, 10, 20, and 50 GeV (upper left to lower right).
png pdf	Figure 4-a: Expected and observed 95% CL cross section upper limits for the combined 2016, 2017, and 2018 datasets as a function of $\tau$ mass in the purely left-handed $\tau$ scenario for $\tilde{\chi}^0_1$ masses of 1, 10, 20, and 50 GeV (upper left to lower right).
png pdf	Figure 4-b: Expected and observed 95% CL cross section upper limits for the combined 2016, 2017, and 2018 datasets as a function of $\tau$ mass in the purely left-handed $\tau$ scenario for $\tilde{\chi}^0_1$ masses of 1, 10, 20, and 50 GeV (upper left to lower right).
png pdf	Figure 4-c: Expected and observed 95% CL cross section upper limits for the combined 2016, 2017, and 2018 datasets as a function of $\tau$ mass in the purely left-handed $\tau$ scenario for $\tilde{\chi}^0_1$ masses of 1, 10, 20, and 50 GeV (upper left to lower right).
png pdf	Figure 4-d: Expected and observed 95% CL cross section upper limits for the combined 2016, 2017, and 2018 datasets as a function of $\tau$ mass in the purely left-handed $\tau$ scenario for $\tilde{\chi}^0_1$ masses of 1, 10, 20, and 50 GeV (upper left to lower right).
png pdf	Figure 5: Expected and observed 95% CL cross section upper limits for the combined 2016, 2017, and 2018 datasets as a function of $\tau$ mass in the purely right-handed $\tau$ scenario for $\tilde{\chi}^0_1$ masses of 1, 10, 20, and 50 GeV (upper left to lower right).
png pdf	Figure 5-a: Expected and observed 95% CL cross section upper limits for the combined 2016, 2017, and 2018 datasets as a function of $\tau$ mass in the purely right-handed $\tau$ scenario for $\tilde{\chi}^0_1$ masses of 1, 10, 20, and 50 GeV (upper left to lower right).
png pdf	Figure 5-b: Expected and observed 95% CL cross section upper limits for the combined 2016, 2017, and 2018 datasets as a function of $\tau$ mass in the purely right-handed $\tau$ scenario for $\tilde{\chi}^0_1$ masses of 1, 10, 20, and 50 GeV (upper left to lower right).
png pdf	Figure 5-c: Expected and observed 95% CL cross section upper limits for the combined 2016, 2017, and 2018 datasets as a function of $\tau$ mass in the purely right-handed $\tau$ scenario for $\tilde{\chi}^0_1$ masses of 1, 10, 20, and 50 GeV (upper left to lower right).
png pdf	Figure 5-d: Expected and observed 95% CL cross section upper limits for the combined 2016, 2017, and 2018 datasets as a function of $\tau$ mass in the purely right-handed $\tau$ scenario for $\tilde{\chi}^0_1$ masses of 1, 10, 20, and 50 GeV (upper left to lower right).
png pdf	Figure 6: Upper limits at 95% CL on the cross section for degenerate (left) and purely left-handed (right) $\tau$ pair production in the $m(\tau )-m(\tilde{\chi}^0_1)$ plane for the combined 2016, 2017, and 2018 datasets. The thick black (red) curves show the observed (expected) exclusion limits assuming NLO+NLL predictions for the signal cross sections. The thin black curves represent the variations in the observed limits obtained when varying the cross sections by their $\pm$ 1 standard deviation uncertainties. The thin dashed red curves indicate the region containing 68% of the distribution of limits expected under the background-only hypothesis.
png pdf	Figure 6-a: Upper limits at 95% CL on the cross section for degenerate (left) and purely left-handed (right) $\tau$ pair production in the $m(\tau )-m(\tilde{\chi}^0_1)$ plane for the combined 2016, 2017, and 2018 datasets. The thick black (red) curves show the observed (expected) exclusion limits assuming NLO+NLL predictions for the signal cross sections. The thin black curves represent the variations in the observed limits obtained when varying the cross sections by their $\pm$ 1 standard deviation uncertainties. The thin dashed red curves indicate the region containing 68% of the distribution of limits expected under the background-only hypothesis.
png pdf	Figure 6-b: Upper limits at 95% CL on the cross section for degenerate (left) and purely left-handed (right) $\tau$ pair production in the $m(\tau )-m(\tilde{\chi}^0_1)$ plane for the combined 2016, 2017, and 2018 datasets. The thick black (red) curves show the observed (expected) exclusion limits assuming NLO+NLL predictions for the signal cross sections. The thin black curves represent the variations in the observed limits obtained when varying the cross sections by their $\pm$ 1 standard deviation uncertainties. The thin dashed red curves indicate the region containing 68% of the distribution of limits expected under the background-only hypothesis.
png pdf	Figure 7: Expected and observed 95% CL cross section upper limits for the combined 2016, 2017, and 2018 datasets as a function of $\tau$ mass for long-lived $\tau$ in the maximally-mixed scenario for an LSP mass of 1 GeV, and for ${c\tau _{0}}$ values of 0.01, 0.05, 0.1, 0.5, 1, and 2.5 mm (upper left to lower right).
png pdf	Figure 7-a: Expected and observed 95% CL cross section upper limits for the combined 2016, 2017, and 2018 datasets as a function of $\tau$ mass for long-lived $\tau$ in the maximally-mixed scenario for an LSP mass of 1 GeV, and for ${c\tau _{0}}$ values of 0.01, 0.05, 0.1, 0.5, 1, and 2.5 mm (upper left to lower right).
png pdf	Figure 7-b: Expected and observed 95% CL cross section upper limits for the combined 2016, 2017, and 2018 datasets as a function of $\tau$ mass for long-lived $\tau$ in the maximally-mixed scenario for an LSP mass of 1 GeV, and for ${c\tau _{0}}$ values of 0.01, 0.05, 0.1, 0.5, 1, and 2.5 mm (upper left to lower right).
png pdf	Figure 7-c: Expected and observed 95% CL cross section upper limits for the combined 2016, 2017, and 2018 datasets as a function of $\tau$ mass for long-lived $\tau$ in the maximally-mixed scenario for an LSP mass of 1 GeV, and for ${c\tau _{0}}$ values of 0.01, 0.05, 0.1, 0.5, 1, and 2.5 mm (upper left to lower right).
png pdf	Figure 7-d: Expected and observed 95% CL cross section upper limits for the combined 2016, 2017, and 2018 datasets as a function of $\tau$ mass for long-lived $\tau$ in the maximally-mixed scenario for an LSP mass of 1 GeV, and for ${c\tau _{0}}$ values of 0.01, 0.05, 0.1, 0.5, 1, and 2.5 mm (upper left to lower right).
png pdf	Figure 7-e: Expected and observed 95% CL cross section upper limits for the combined 2016, 2017, and 2018 datasets as a function of $\tau$ mass for long-lived $\tau$ in the maximally-mixed scenario for an LSP mass of 1 GeV, and for ${c\tau _{0}}$ values of 0.01, 0.05, 0.1, 0.5, 1, and 2.5 mm (upper left to lower right).
png pdf	Figure 7-f: Expected and observed 95% CL cross section upper limits for the combined 2016, 2017, and 2018 datasets as a function of $\tau$ mass for long-lived $\tau$ in the maximally-mixed scenario for an LSP mass of 1 GeV, and for ${c\tau _{0}}$ values of 0.01, 0.05, 0.1, 0.5, 1, and 2.5 mm (upper left to lower right).

Tables
png pdf	Table 1: Ranges of ${\Sigma {m_{\mathrm {T}}}}$ , ${m_{\mathrm {T2}}}$ , and ${{p_{\mathrm {T}}} ^{{\tau _\mathrm {h}} \, 1}}$ used to define the prompt search regions for the ${N_{\text {j}}} =$ 0 and ${N_{\text {j}}} \geq$ 1 event categories, and ranges of ${{p_{\mathrm {T}}} ^{{\tau _\mathrm {h}} \, 2}}$ used to define the displaced search regions.
png pdf	Table 2: Uncertainties in the analysis affecting signal and the SM backgrounds. The ranges shown for signal correpond to a representative benchmark model of left-handed $\tau$ pair production with $m({\tau _{\mathrm {L}}})=$ 150 GeV, $m(\tilde{\chi}^0_1)=$ 1 GeV.
png pdf	Table 3: Predicted SM background yields, observed event counts, and predicted signal yields for two benchmark models with a $\tau$ mass of 150 GeV and an LSP mass of 1 GeV, in all prompt and displaced SRs as labelled in Table 1, corresponding to 137fb $^{-1}$ of data. For the prompt signal model shown, we assume left-handed $\tau$ pair production, while for the displaced signal model we assume a maximally-mixed scenario and $c\tau _{0}(\tau )=$ 0.5 mm. The uncertainties listed are the sum in quadrature of statistical and systematic uncertainties. For any estimate with no events in the data sideband, embedded, or simulation sample corresponding to a given SR selection, we provide the one standard deviation upper bound evaluated for that estimate.

Summary

A search for direct

$\tau$ slepton (

$\tilde{\tau}$ ) pair production has been performed in proton-proton collisions at a center-of-mass energy of 13 TeV in events with a

$\tau$ lepton pair and significant missing transverse momentum. Both prompt and displaced decays of the

$\tau$ slepton are studied. Thirty-one different search regions are used in the analysis, based on kinematic observables that exploit expected differences between signal and background. The data used for this search correspond to an integrated luminosity of 137fb

$^{-1}$ collected in 2016, 2017, and 2018 with the CMS detector. No excess of events above the expected standard model background has been observed. Upper limits have been set on the cross section for direct

$\tilde{\tau}$ pair production for simplified models in which each

$\tilde{\tau}$ decays to a

$\tau$ lepton and the lightest neutralino, with the latter being assumed to be the lightest supersymmetric particle (LSP). For purely left-handed

$\tilde{\tau}$ pair production with prompt decays,

$\tilde{\tau}$ masses between 115 and 340 GeV are excluded for the case of a nearly massless LSP. In scenarios with macroscopic

$\tilde{\tau}$ decay lengths corresponding to

$c\tau =$ 0.1mm, masses between 150 and 220 GeV are excluded for the case that the LSP is nearly massless.

References
1	P. Ramond	Dual theory for free fermions	PRD 3 (1971) 2415
2	Y. A. Gol'fand and E. P. Likhtman	Extension of the algebra of Poincar $\'e$ group generators and violation of P invariance	JEPTL 13 (1971)323
3	A. Neveu and J. H. Schwarz	Factorizable dual model of pions	NPB 31 (1971) 86
4	D. V. Volkov and V. P. Akulov	Possible universal neutrino interaction	JEPTL 16 (1972)438
5	J. Wess and B. Zumino	A Lagrangian model invariant under supergauge transformations	PLB 49 (1974) 52
6	J. Wess and B. Zumino	Supergauge transformations in four dimensions	NPB 70 (1974) 39
7	P. Fayet	Supergauge invariant extension of the Higgs mechanism and a model for the electron and its neutrino	NPB 90 (1975) 104
8	H. P. Nilles	Supersymmetry, supergravity and particle physics	Phys. Rep. 110 (1984) 1
9	E. Gildener	Gauge Symmetry Hierarchies	PRD 14 (1976) 1667
10	M. J. G. Veltman	Second Threshold in Weak Interactions	Acta Phys. Polon. B 8 (1977)475
11	G. 't Hooft	Naturalness, chiral symmetry, and spontaneous chiral symmetry breaking	NATO Sci. Ser. B 59 (1980)135
12	E. Witten	Dynamical breaking of supersymmetry	NPB 188 (1981) 513
13	G. R. Farrar and P. Fayet	Phenomenology of the production, decay, and detection of new hadronic states associated with supersymmetry	PLB 76 (1978) 575
14	H. Goldberg	Constraint on the Photino Mass from Cosmology	PRL 50 (1983) 1419
15	J. R. Ellis et al.	Supersymmetric Relics from the Big Bang	NPB 238 (1984) 453--476
16	G. Jungman, M. Kamionkowski, and K. Griest	Supersymmetric dark matter	PR 267 (1996) 195	hep-ph/9506380
17	G. Hinshaw et al.	Nine-year Wilkinson Microwave Anisotropy Probe (WMAP) observations: cosmological parameter results	Astrophys. J. Suppl. 208 (2013) 19	1212.5226
18	K. Griest and D. Seckel	Three exceptions in the calculation of relic abundances	PRD 43 (1991) 3191
19	D. A. Vasquez, G. Bélanger, and C. Boehm	Revisiting light neutralino scenarios in the MSSM	PRD 84 (2011) 095015	1108.1338
20	S. F. King, J. P. Roberts, and D. P. Roy	Natural dark matter in SUSY GUTs with non-universal gaugino masses	JHEP 10 (2007) 106	0705.4219
21	M. Battaglia et al.	Proposed post-LEP benchmarks for supersymmetry	EPJC 22 (2001) 535	hep-ph/0106204
22	R. L. Arnowitt et al.	Determining the dark matter relic density in the minimal supergravity stau-neutralino coannihilation region at the Large Hadron Collider	PRL 100 (2008) 231802	0802.2968
23	G. B\'elanger, S. Biswas, C. Boehm, and B. Mukhopadhyaya	Light neutralino dark matter in the MSSM and its implication for LHC searches for staus	JHEP 12 (2012) 076	1206.5404
24	E. Arganda, V. Martin-Lozano, A. D. Medina, and N. Mileo	Potential discovery of staus through heavy Higgs boson decays at the LHC	JHEP 09 (2018) 056	1804.10698
25	J. A. Evans and J. Shelton	Long-Lived Staus and Displaced Leptons at the LHC	JHEP 04 (2016) 056	1601.01326
26	J. Alwall, P. Schuster, and N. Toro	Simplified models for a first characterization of new physics at the LHC	PRD 79 (2009) 075020	0810.3921
27	J. Alwall, M.-P. Le, M. Lisanti, and J. Wacker	Model-independent jets plus missing energy searches	PRD 79 (2009) 015005	0809.3264
28	LHC New Physics Working Group	Simplified models for LHC new physics searches	JPG 39 (2012) 105005	1105.2838
29	ALEPH Collaboration	Search for scalar leptons in e $^{+}$ e $^{-}$ collisions at center-of-mass energies up to 209 GeV	PLB 526 (2002) 206	hep-ex/0112011
30	DELPHI Collaboration	Searches for supersymmetric particles in e $^{+}$ e $^{-}$ collisions up to 208 GeV and interpretation of the results within the MSSM	EPJC 31 (2003) 421	hep-ex/0311019
31	L3 Collaboration	Search for scalar leptons and scalar quarks at LEP	PLB 580 (2004) 37	hep-ex/0310007
32	OPAL Collaboration	Search for anomalous production of dilepton events with missing transverse momentum in e $^{+}$ e $^{-}$ collisions at $\sqrt{s} =$ 183 GeV to 209 GeV	EPJC 32 (2004) 453	hep-ex/0309014
33	ATLAS Collaboration	Search for the direct production of charginos, neutralinos and staus in final states with at least two hadronically decaying taus and missing transverse momentum in pp collisions at $\sqrt{s} =$ 8 TeV with the ATLAS detector	JHEP 10 (2014) 96	1407.0350
34	ATLAS Collaboration	Search for the electroweak production of supersymmetric particles in $\sqrt{s} =$ 8 TeV pp collisions with the ATLAS detector	PRD 93 (2016) 052002	1509.07152
35	CMS Collaboration	Search for electroweak production of charginos in final states with two tau leptons in pp collisions at $\sqrt{s}=$ 8 TeV	JHEP 04 (2017) 018	CMS-SUS-14-022 1610.04870
36	ATLAS Collaboration	Search for direct stau production in events with two hadronic $\tau$ -leptons in $\sqrt{s} =$ 13 TeV pp collisions with the ATLAS detector	PRD 101 (2020) 032009	1911.06660
37	CMS Collaboration	Search for direct pair production of supersymmetric partners to the $\tau$ lepton in proton-proton collisions at $\sqrt{s}=$ 13 TeV	EPJC 80 (2020) 189	CMS-SUS-18-006 1907.13179
38	B. Fuks, M. Klasen, D. R. Lamprea, and M. Rothering	Revisiting slepton pair production at the Large Hadron Collider	JHEP 01 (2014) 168	1310.2621
39	OPAL Collaboration	Searches for gauge-mediated supersymmetry breaking topologies in e $^{+}$ e $^{-}$ collisions at LEP2	EPJC 46 (2006) 307--341	hep-ex/0507048
40	ATLAS Collaboration	Search for displaced leptons in $\sqrt{s} =$ 13 TeV pp collisions with the ATLAS detector	(11, 2020). Submitted to PRLett	2011.07812
41	CMS Collaboration	An embedding technique to determine $\tau\tau$ backgrounds in proton-proton collision data	JINST 14 (2019), no. 06, P06032	CMS-TAU-18-001 1903.01216
42	CMS Collaboration	The CMS trigger system	JINST 12 (2017) P01020	CMS-TRG-12-001 1609.02366
43	CMS Collaboration	The CMS experiment at the CERN LHC	JINST 3 (2008) S08004	CMS-00-001
44	CMS Collaboration	Particle-flow reconstruction and global event description with the CMS detector	JINST 12 (2017) P10003	CMS-PRF-14-001 1706.04965
45	CMS Collaboration	Performance of missing transverse momentum reconstruction in proton-proton collisions at $\sqrt{s} =$ 13 TeV using the CMS detector	JINST 14 (2019) P07004	CMS-JME-17-001 1903.06078
46	M. Cacciari, G. P. Salam, and G. Soyez	The anti- ${k_{\mathrm{T}}}$ jet clustering algorithm	JHEP 04 (2008) 063	0802.1189
47	M. Cacciari, G. P. Salam, and G. Soyez	FastJet user manual	EPJC 72 (2012) 1896	1111.6097
48	CMS Collaboration	Study of pileup removal algorithms for jets	CMS-PAS-JME-14-001	CMS-PAS-JME-14-001
49	CMS Collaboration	Identification of heavy-flavour jets with the CMS detector in pp collisions at 13 TeV	JINST 13 (2018) P05011	CMS-BTV-16-002 1712.07158
50	CMS Collaboration	Performance of reconstruction and identification of $\tau$ leptons decaying to hadrons and $\nu_\tau$ in pp collisions at $\sqrt{s}=$ 13 TeV	JINST 13 (2018) P10005	CMS-TAU-16-003 1809.02816
51	J. Alwall et al.	The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations	JHEP 07 (2014) 079	1405.0301
52	T. Sjostrand et al.	An introduction to PYTHIA 8.2	CPC 191 (2015) 159	1410.3012
53	CMS Collaboration	Event generator tunes obtained from underlying event and multiparton scattering measurements	EPJC 76 (2016) 155	CMS-GEN-14-001 1512.00815
54	CMS Collaboration	Extraction and validation of a new set of CMS PYTHIA8 tunes from underlying-event measurements	EPJC 80 (2020) 4	CMS-GEN-17-001 1903.12179
55	NNPDF Collaboration	Parton distributions for the LHC Run II	JHEP 04 (2015) 040	1410.8849
56	GEANT4 Collaboration	GEANT4 --- a simulation toolkit	NIMA 506 (2003) 250
57	A. Kalogeropoulos and J. Alwall	The SysCalc code: A tool to derive theoretical systematic uncertainties		1801.08401
58	P. Nason	A new method for combining NLO QCD with shower Monte Carlo algorithms	JHEP 11 (2004) 040	hep-ph/0409146
59	S. Frixione, P. Nason, and C. Oleari	Matching NLO QCD computations with parton shower simulations: the POWHEG method	JHEP 11 (2007) 070	0709.2092
60	S. Alioli, P. Nason, C. Oleari, and E. Re	A general framework for implementing NLO calculations in shower Monte Carlo programs: the POWHEG BOX	JHEP 06 (2010) 043	1002.2581
61	E. Re	Single-top $Wt$ -channel production matched with parton showers using the POWHEG method	EPJC 71 (2011) 1547	1009.2450
62	CMS Collaboration	Search for top-squark pair production in the single-lepton final state in pp collisions at $\sqrt{s} =$ 8 TeV	EPJC 73 (2013) 2677	CMS-SUS-13-011 1308.1586
63	C. G. Lester and D. J. Summers	Measuring masses of semi-invisibly decaying particle pairs produced at hadron colliders	PLB 463 (1999) 99	hep-ph/9906349
64	A. Barr, C. Lester, and P. Stephens	$m_{\mathrm{T2}}$ : the truth behind the glamour	JPG 29 (2003) 2343	hep-ph/0304226
65	C. G. Lester and B. Nachman	Bisection-based asymmetric $m_{\mathrm{T2}}$ computation: a higher precision calculator than existing symmetric methods	JHEP 03 (2015) 100	1411.4312
66	CMS Collaboration	Precision luminosity measurement in proton-proton collisions at $\sqrt{s} =$ 13 TeV in 2015 and 2016 at CMS	Submitted to EPJC	CMS-LUM-17-003 2104.01927
67	CMS Collaboration	CMS luminosity measurement for the 2017 data-taking period at $\sqrt{s} =$ 13 TeV	CMS-PAS-LUM-17-004	CMS-PAS-LUM-17-004
68	CMS Collaboration	CMS luminosity measurement for the 2018 data-taking period at $\sqrt{s} =$ 13 TeV	CMS-PAS-LUM-18-002	CMS-PAS-LUM-18-002
69	CMS Collaboration	Interpretation of searches for supersymmetry with simplified models	PRD 88 (2013) 052017	CMS-SUS-11-016 1301.2175
70	T. Junk	Confidence level computation for combining searches with small statistics	NIMA 434 (1999) 435	hep-ex/9902006
71	A. L. Read	Presentation of search results: the $\text{CL}_\text{s}$ technique	JPG 28 (2002) 2693
72	The ATLAS Collaboration, The CMS Collaboration, The LHC Higgs Combination Group	Procedure for the LHC Higgs boson search combination in Summer 2011	CMS-NOTE-2011-005
73	G. Cowan, K. Cranmer, E. Gross, and O. Vitells	Asymptotic formulae for likelihood-based tests of new physics	EPJC 71 (2011) 1554	1007.1727