CMS-PAS-SUS-17-008

CMS-PAS-SUS-17-008
Search for resonant production of second generation sleptons with same-sign dimuon events in proton-proton collisions at $\sqrt{s}= $ 13 TeV
CMS Collaboration
June 2018

Abstract: A search for resonant production of second generation sleptons ($\tilde{\mu}$, $\tilde{\nu}_{\mu}$) via the R-parity-violating coupling $\lambda'_{211}$, in events with two same-sign muons and at least two jets in the final state is presented. While one muon is expected to be produced directly in the slepton decay, the second muon and at least two jets are produced in the subsequent decay of a neutralino or chargino originating from the resonant slepton. The analysis is based on the 2016 dataset of proton-proton collisions at $\sqrt{s}= $ 13 TeV recorded with the CMS detector at the CERN LHC, which corresponds to an integrated luminosity of 35.9 fb$^{-1}$. No significant deviation is observed with respect to standard model expectations. Upper cross section limits are derived in the context of two simplified models representing the dominant signal contributions. The cross section limits are translated into coupling limits for a modified constrained minimal supersymmetric model with $\lambda'_{211}$ as an additional R-parity-violating coupling. The results impose significantly extended restrictions of the parameter space compared to previous searches for similar models.
Links: CDS record (PDF) ; inSPIRE record ; CADI line (restricted) ; These preliminary results are superseded in this paper, EPJC 79 (2019) 305. The superseded preliminary plots can be found here.

Figures & Tables	Summary	References	CMS Publications

Figures
png pdf	Figure 1: Dominant signal contributions in a modified cMSSM with $ {{\lambda ^{\prime}_{211}}} $ as an additional coupling. The left and middle diagrams are simulated as simplified models and considered as signal models for this search.
png pdf	Figure 2: Expected (after fit) and observed event yields in the signal regions as defined in Table xxxxx. The grey band shows the systematic uncertainty on the background yields. Also shown are the expected yields for two signal points normalized to their smallest excluded cross section.
png pdf	Figure 3: Expected (after fit) and observed event yields in the $ {\text {M}_{\text {slepton}}} $ and ${\text {M}_{\tilde\chi}}$ distribution. Also shown are the expected yields for two signal points normalized to their smallest excluded cross section.
png pdf	Figure 3-a: Expected (after fit) and observed event yields in the $ {\text {M}_{\text {slepton}}} $ and ${\text {M}_{\tilde\chi}}$ distribution. Also shown are the expected yields for two signal points normalized to their smallest excluded cross section.
png pdf	Figure 3-b: Expected (after fit) and observed event yields in the $ {\text {M}_{\text {slepton}}} $ and ${\text {M}_{\tilde\chi}}$ distribution. Also shown are the expected yields for two signal points normalized to their smallest excluded cross section.
png pdf	Figure 4: Observed upper cross section limits at 95% CL in the mass plane given by $ {\text {m}_{\tilde\chi ^{0}_{1}}} $ and $ {\text {m}_{\tilde\mu}} $ or $ {\text {m}_{\tilde\nu}} $ for sm1 or sm2, respectively. The limit for a specific mass combination is depicted according to the color scale on the right-hand side of the figures.
png pdf	Figure 4-a: Observed upper cross section limits at 95% CL in the mass plane given by $ {\text {m}_{\tilde\chi ^{0}_{1}}} $ and $ {\text {m}_{\tilde\mu}} $ or $ {\text {m}_{\tilde\nu}} $ for sm1 or sm2, respectively. The limit for a specific mass combination is depicted according to the color scale on the right-hand side of the figures.
png pdf	Figure 4-b: Observed upper cross section limits at 95% CL in the mass plane given by $ {\text {m}_{\tilde\chi ^{0}_{1}}} $ and $ {\text {m}_{\tilde\mu}} $ or $ {\text {m}_{\tilde\nu}} $ for sm1 or sm2, respectively. The limit for a specific mass combination is depicted according to the color scale on the right-hand side of the figures.
png pdf	Figure 4-c: Observed upper cross section limits at 95% CL in the mass plane given by $ {\text {m}_{\tilde\chi ^{0}_{1}}} $ and $ {\text {m}_{\tilde\mu}} $ or $ {\text {m}_{\tilde\nu}} $ for sm1 or sm2, respectively. The limit for a specific mass combination is depicted according to the color scale on the right-hand side of the figures.
png pdf	Figure 4-d: Observed upper cross section limits at 95% CL in the mass plane given by $ {\text {m}_{\tilde\chi ^{0}_{1}}} $ and $ {\text {m}_{\tilde\mu}} $ or $ {\text {m}_{\tilde\nu}} $ for sm1 or sm2, respectively. The limit for a specific mass combination is depicted according to the color scale on the right-hand side of the figures.
png pdf	Figure 5: Upper coupling limits as a function of $ {\text {m}_{0}} $ and $ {\text {m}_{1/2}} $ for a modified cMSSM with $ {{\lambda ^{\prime}_{211}}} $ as additional RPV coupling. The color scale at the right side of the figure indicates the coupling limit value for specific parameter combinations. These limits are derived from the upper cross section limits of sm1. For four $ {{\lambda ^{\prime}_{211}}} $ values (0.004, 0.01, 0.02, 0.03), the coupling limits are shown as black contour line.

Tables
png pdf	Table 1: Sources of systematic uncertainties considered in this search and their values and impact ranges in the different signal regions. The background values are given with respect to the processes they concern, while the impacts are normalized to the total event yield in each signal region. For the signal, typical values for the most relevant signal regions are given. The first three blocks affect the backgrounds predictions and list all experimental uncertainties, uncertainties for processes where the yield is obtained from data, and additional uncertainties for simulation based backgrounds. For signal, the first and the last block are relevant.
png pdf	Table 2: Expected and observed event yields in the signal regions. The uncertainties are the total systematic uncertainties on the expected yields. Also shown are the expected yields for two signal points normalized to their smallest excludable cross-section.
png pdf	Table 3: Observed upper coupling limits for the full cMSSM-like model with $ {{\lambda ^{\prime}_{211}}} $ as additional coupling based on sm2 points. The masses and upper limits on the cross sections at 95% CL for the corresponding points are also shown.

Summary

A search for resonant production of second generation sleptons ($\tilde{\mu}$, $\tilde{\nu}_{\mu}$) with 35.9 fb$^{-1}$ of proton-proton collisions recorded in 2016 with the CMS detector has been presented. The search targets resonant slepton production via the RPV coupling $ {{\lambda^{\prime}_{211}}} $ in final states with two same-sign muons and at least two jets in the final state. No significant excess over the background expectation is observed. Upper cross section limits are set in the context of two simplified models covering the dominant production mechanisms in a modified constrained minimal supersymmetric model with $ {{\lambda^{\prime}_{211}}} $ as additional coupling. These exclusion limits are translated into $ {{\lambda^{\prime}_{211}}} $ coupling limits. The results represent the most stringent limits on this particular model of RPV SUSY.

References
1	H. P. Nilles	Supersymmetry, Supergravity and Particle Physics	PR 110 (1984) 1
2	H. E. Haber and G. L. Kane	The Search for Supersymmetry: Probing Physics Beyond the Standard Model	PR 117 (1985) 75
3	S. P. Martin	A Supersymmetry primer	Adv. Ser. Direct. High Energy Phys. 21 (2010) 1	hep-ph/9709356
4	L. E. Ib\'a\ nez and G. Ross	Discrete gauge symmetries and the origin of baryon and lepton number conservation in supersymmetric versions of the standard model	NPB 368 (1992) 3
5	H. K. Dreiner, C. Luhn, and M. Thormeier	What is the discrete gauge symmetry of the MSSM?	PRD 73 (2006) 075007	hep-ph/0512163
6	G. L. Kane, C. Kolda, L. Roszkowski, and J. D. Wells	Study of constrained minimal supersymmetry	PRD 49 (1994) 6173
7	D0 Collaboration	Search for resonant second generation slepton production at the Tevatron	PRL 97 (2006) 111801	hep-ex/0605010
8	CMS Collaboration	The CMS experiment at the CERN LHC	JINST 3 (2008) S08004	CMS-00-001
9	CMS Collaboration	The CMS trigger system	JINST 12 (2017) P01020	CMS-TRG-12-001 1609.02366
10	CMS Collaboration	Particle-flow reconstruction and global event description with the CMS detector	JINST 12 (2017) P10003	CMS-PRF-14-001 1706.04965
11	M. Cacciari, G. P. Salam, and G. Soyez	The anti-$ k_t $ jet clustering algorithm	JHEP 04 (2008) 063	0802.1189
12	M. Cacciari, G. P. Salam, and G. Soyez	FastJet user manual	EPJC 72 (2012) 1896	1111.6097
13	CMS Collaboration	Jet energy scale and resolution in the CMS experiment in pp collisions at 8 TeV	JINST 12 (2017) P02014	CMS-JME-13-004 1607.03663
14	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
15	CMS Collaboration	Performance of CMS muon reconstruction in $ pp $ collision events at $ \sqrt{s} = $ 7 TeV	JINST 7 (2012) P10002	CMS-MUO-10-004 1206.4071
16	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
17	J. Alwall et al.	Comparative study of various algorithms for the merging of parton showers and matrix elements in hadronic collisions	EPJC 53 (2008) 473	0706.2569
18	J. Alwall, S. de Visscher, and F. Maltoni	QCD radiation in the production of heavy colored particles at the LHC	JHEP 02 (2009) 017	0810.5350
19	R. Frederix and S. Frixione	Merging meets matching in MC@NLO	JHEP 12 (2012) 061	1209.6215
20	P. Nason	A New method for combining NLO QCD with shower Monte Carlo algorithms	JHEP 11 (2004) 040	hep-ph/0409146
21	S. Frixione, P. Nason, and C. Oleari	Matching NLO QCD computations with Parton Shower simulations: the POWHEG method	JHEP 11 (2007) 070	0709.2092
22	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
23	T. Melia, P. Nason, R. Rontsch, and G. Zanderighi	$ \mathrm{W}^+ \mathrm{W}^- $, $ \mathrm{W} \mathrm{Z} $ and $ \mathrm{Z} \mathrm{Z} $ production in the POWHEG BOX	JHEP 11 (2011) 078	1107.5051
24	P. Nason and G. Zanderighi	$ \mathrm{W}^+ \mathrm{W}^- $, $ \mathrm{W} \mathrm{Z} $ and $ \mathrm{Z} \mathrm{Z} $ production in the POWHEG-BOX-V2	EPJC 74 (2014) 2702	1311.1365
25	H. B. Hartanto, B. Jager, L. Reina, and D. Wackeroth	Higgs boson production in association with top quarks in the POWHEG BOX	PRD 91 (2015) 094003	1501.04498
26	E. Bagnaschi, G. Degrassi, P. Slavich, and A. Vicini	Higgs production via gluon fusion in the POWHEG approach in the SM and in the MSSM	JHEP 02 (2012) 088	1111.2854
27	T. Sjostrand, S. Mrenna, and P. Z. Skands	A brief introduction to PYTHIA 8.1	CPC 178 (2008) 852	0710.3820
28	P. Skands, S. Carrazza, and J. Rojo	Tuning PYTHIA 8.1: the Monash 2013 tune	EPJC 74 (2014) 3024	1404.5630
29	CMS Collaboration	Event generator tunes obtained from underlying event and multiparton scattering measurements	EPJC 76 (2016) 155	CMS-GEN-14-001 1512.00815
30	NNPDF Collaboration	Parton distributions for the LHC Run II	JHEP 04 (2015) 040	1410.8849
31	GEANT4 Collaboration	GEANT4---a simulation toolkit	NIMA 506 (2003) 250
32	S. Abdullin et al.	The fast simulation of the CMS detector at LHC	J. Phys. Conf. Ser. 331 (2011) 032049
33	F. Staub	SARAH 4 : A tool for (not only SUSY) model builders	CPC 185 (2014) 1773	1309.7223
34	F. Staub, T. Ohl, W. Porod, and C. Speckner	A Tool Box for Implementing Supersymmetric Models	CPC 183 (2012) 2165	1109.5147
35	M. D. Goodsell, K. Nickel, and F. Staub	Two-Loop Higgs mass calculations in supersymmetric models beyond the MSSM with SARAH and SPheno	EPJC 75 (2015) 32	1411.0675
36	F. Staub and W. Porod	Improved predictions for intermediate and heavy Supersymmetry in the MSSM and beyond	EPJC 77 (2017) 338	1703.03267
37	W. Porod	SPheno, a program for calculating supersymmetric spectra, SUSY particle decays and SUSY particle production at e+ e- colliders	CPC 153 (2003) 275	hep-ph/0301101
38	W. Porod and F. Staub	SPheno 3.1: Extensions including flavour, CP-phases and models beyond the MSSM	CPC 183 (2012) 2458	1104.1573
39	CMS Collaboration	Search for new physics in same-sign dilepton events in proton-proton collisions at $ \sqrt{s} = $ 13 TeV	EPJC 76 (2016) 439	CMS-SUS-15-008 1605.03171
40	CMS Collaboration	Reconstruction and identification of $ \tau $ lepton decays to hadrons and $ \nu_\tau $ at CMS	JINST 11 (2016) P01019	CMS-TAU-14-001 1510.07488
41	CMS Collaboration	Search for physics beyond the standard model in events with two leptons of same sign, missing transverse momentum, and jets in proton-proton collisions at $ \sqrt{s} = $ 13 TeV	EPJC 77 (2017) 578	CMS-SUS-16-035 1704.07323
42	CMS Collaboration	CMS Luminosity Measurements for the 2016 Data Taking Period	CMS-PAS-LUM-17-001	CMS-PAS-LUM-17-001
43	R. D. Cousins, K. E. Hymes, and J. Tucker	Frequentist evaluation of intervals estimated for a binomial parameter and for the ratio of poisson means	NIMA 612 (2010) 388
44	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
45	T. Junk	Confidence level computation for combining searches with small statistics	NIMA 434 (1999) 435	hep-ex/9902006
46	A. L. Read	Presentation of search results: The $ CL_s $ technique	JPG 28 (2002) 2693
47	G. Cowan, K. Cranmer, E. Gross, and O. Vitells	Asymptotic formulae for likelihood-based tests of new physics	EPJC 71 (2011) 1554	1007.1727
48	ATLAS and CMS Collaborations	Procedure for the LHC Higgs boson search combination in summer 2011	CMS-NOTE-2011-005