Charged sleptons

This section contains limits on charged scalar leptons (${{\widetilde{\mathit \ell}}}$, with ${{\mathit \ell}}={{\mathit e}},{{\mathit \mu}},{{\mathit \tau}}$). Studies of width and decays of the ${{\mathit Z}}$ boson (use is made here of $\Delta \Gamma _{{\mathrm {inv}}}<2.0~$MeV, LEP 2000 ) conclusively rule out ${\mathit m}_{{{\widetilde{\mathit \ell}}_{{R}}}}<40~$GeV (41 GeV for ${{\widetilde{\mathit \ell}}_{{L}}}$) , independently of decay modes, for each individual slepton. The limits improve to 43$~$GeV ($43.5$ GeV for ${{\widetilde{\mathit \ell}}_{{L}}}$) assuming all 3 flavors to be degenerate. Limits on higher mass sleptons depend on model assumptions and on the mass splitting $\Delta \mathit m$= ${\mathit m}_{{{\widetilde{\mathit \ell}}}}–{\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$. The mass and composition of ${{\widetilde{\mathit \chi}}_{{1}}^{0}}$ may affect the selectron production rate in ${{\mathit e}^{+}}{{\mathit e}^{-}}$ collisions through ${{\mathit t}}$-channel exchange diagrams. Production rates are also affected by the potentially large mixing angle of the lightest mass eigenstate ${{\widetilde{\mathit \ell}}_{{1}}}={{\widetilde{\mathit \ell}}_{{R}}}$ sin$\theta _{{{\mathit \ell}}}$ + ${{\widetilde{\mathit \ell}}_{{L}}}$ cos $\theta _{{{\mathit \ell}}}$. It is generally assumed that only ${{\widetilde{\mathit \tau}}}$ may have significant mixing. The coupling to the ${{\mathit Z}}$ vanishes for $\theta _{{{\mathit \ell}}}$=0.82. In the high-energy limit of ${{\mathit e}^{+}}{{\mathit e}^{-}}$ collisions the interference between ${{\mathit \gamma}}$ and ${{\mathit Z}}$ exchange leads to a minimal cross section for $\theta _{{{\mathit \ell}}}$=0.91, a value which is sometimes used in the following entries relative to data taken at LEP2. When limits on ${\mathit m}_{{{\widetilde{\mathit \ell}}_{{R}}}}$ are quoted, it is understood that limits on ${\mathit m}_{{{\widetilde{\mathit \ell}}_{{L}}}}$ are usually at least as strong.
Possibly open decays involving gauginos other than ${{\widetilde{\mathit \chi}}_{{1}}^{0}}$ will affect the detection efficiencies. Unless otherwise stated, the limits presented here result from the study of ${{\widetilde{\mathit \ell}}^{+}}{{\widetilde{\mathit \ell}}^{-}}$ production, with production rates and decay properties derived from the MSSM. Limits made obsolete by the recent analyses of ${{\mathit e}^{+}}{{\mathit e}^{-}}$ collisions at high energies can be found in previous Editions of this Review.
For decays with final state gravitinos (${{\widetilde{\mathit G}}}$), ${\mathit m}_{{{\widetilde{\mathit G}}}}$ is assumed to be negligible relative to all other masses.

R-parity violating ${{\widetilde{\boldsymbol \mu}}}$ (Smuon) mass limit INSPIRE search

$> 780$ 95 1
ATLS ${}\geq{}4{{\mathit \ell}}$, ${{\mathit \lambda}_{{i33}}}{}\not=$0, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$=300 GeV (mass-degenerate left-handed sleptons and sneutrinos of all 3 generations)
$> 1060$ 95 1
ATLS ${}\geq{}4{{\mathit \ell}}$, ${{\mathit \lambda}_{{12k}}}{}\not=$0, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$=600 GeV (mass-degenerate left-handed sleptons and sneutrinos of all 3 generations)
$\bf{> 410}$ 95 2
ATLS RPV, ${}\geq{}4{{\mathit \ell}^{\pm}}$, ${{\widetilde{\mathit \ell}}}$ $\rightarrow$ ${{\mathit \ell}}{{\widetilde{\mathit \chi}}_{{1}}^{0}}$ , ${{\widetilde{\mathit \chi}}_{{1}}^{0}}$ $\rightarrow$ ${{\mathit \ell}^{\pm}}{{\mathit \ell}^{\mp}}{{\mathit \nu}}$
• • • We do not use the following data for averages, fits, limits, etc. • • •
${{\mathit \mu}^{\pm}}{{\mathit \mu}^{\pm}}$ + ${}\geq{}$2jets, ${{\mathit \lambda}_{{211}}^{\,'}}{}\not=$0, ${{\widetilde{\mathit \mu}}_{{L}}}$ $\rightarrow$ ${{\mathit \mu}}{{\widetilde{\mathit \chi}}_{{1}}^{0}}$ , ${{\widetilde{\mathit \chi}}_{{1}}^{0}}$ $\rightarrow$ ${{\mathit \mu}}{{\mathit q}}{{\overline{\mathit q}}}$
$> 87$ 95 4
DLPH RPV, ${{\widetilde{\mathit \mu}}_{{R}}}$, indirect, $\Delta \mathit m>$5~GeV
$>81$ 95 5
ALEP RPV, ${{\widetilde{\mathit \mu}}_{{L}}}$
1  AABOUD 2018Z searched in 36.1 ${\mathrm {fb}}{}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV for events containing four or more charged leptons (electrons, muons and up to two hadronically decaying taus). No significant deviation from the expected SM background is observed. Limits are set on the Higgsino mass in simplified models of general gauge mediated supersymmetry Tn1n1A/Tn1n1B/Tn1n1C, see their Figure 9. Limits are also set on the wino, slepton, sneutrino and gluino mass in a simplified model of NLSP pair production with R-parity violating decays of the LSP via ${{\mathit \lambda}_{{12k}}}$ or ${{\mathit \lambda}_{{i33}}}$ to charged leptons, see their Figures 7, 8.
2  AAD 2014X searched in 20.3 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 8 TeV for events with at least four leptons (electrons, muons, taus) in the final state. No significant excess above the Standard Model expectations is observed. Limits are set on the slepton mass in an R-parity violating simplified model where the decay ${{\widetilde{\mathit \ell}}}$ $\rightarrow$ ${{\mathit \ell}}{{\widetilde{\mathit \chi}}_{{1}}^{0}}$ , with ${{\widetilde{\mathit \chi}}_{{1}}^{0}}$ $\rightarrow$ ${{\mathit \ell}^{\pm}}{{\mathit \ell}^{\mp}}{{\mathit \nu}}$ , takes place with a branching ratio of 100$\%$, see Fig. 9.
3  SIRUNYAN 2019AO searched in 35.9 ${\mathrm {fb}}{}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV for events containing two same-sign muons and at last two jets, originating from resonant production of second-generation sleptons (${{\widetilde{\mathit \mu}}_{{L}}}$, ${{\widetilde{\mathit \nu}}_{{\mu}}}$) via the R-parity violating coupling ${{\mathit \lambda}_{{211}}^{\,'}}$ to quarks. No significant excess above the Standard Model expectations is observed. Upper limits on cross sections are derived in the context of two simplified models, see their Figure 4. The cross section limits are translated into limits on ${{\mathit \lambda}_{{211}}^{\,'}}$ for a modified CMSSM, see their Figure 5.
4  ABDALLAH 2004M use data from $\sqrt {s }$ = $192 - 208$~GeV to derive limits on sparticle masses under the assumption of RPV with ${{\mathit L}}{{\mathit L}}{{\overline{\mathit E}}}$ or ${{\overline{\mathit U}}}{{\overline{\mathit D}}}{{\overline{\mathit D}}}$ couplings. The results are valid for ${{\mathit \mu}}$ = $-200$~GeV, tan ${{\mathit \beta}}$ = 1.5, $\Delta \mathit m$ $>$ 5~GeV and assuming a BR of 1 for the given decay. The limit quoted is for indirect ${{\overline{\mathit U}}}{{\overline{\mathit D}}}{{\overline{\mathit D}}}$ decays using the neutralino constraint of 39.5 GeV for ${{\mathit L}}{{\mathit L}}{{\overline{\mathit E}}}$ and of 38.0 GeV for ${{\overline{\mathit U}}}{{\overline{\mathit D}}}{{\overline{\mathit D}}}$ couplings, also derived in ABDALLAH 2004M. For indirect decays via ${{\mathit L}}{{\mathit L}}{{\overline{\mathit E}}}$ the limit improves to 90 GeV if the constraint from the neutralino is used and remains at 87 GeV if it is not used. For indirect decays via ${{\overline{\mathit U}}}{{\overline{\mathit D}}}{{\overline{\mathit D}}}$ couplings it degrades to 85 GeV when the neutralino constraint is not used. Supersedes the result of ABREU 2000U.
5  HEISTER 2003G searches for the production of smuons in the case of RPV prompt decays with $\mathit LL\bar E$, $\mathit LQ\bar D$ or $\bar U \bar D \bar D$ couplings at $\sqrt {s }$ = $189 - 209~$GeV. The search is performed for direct and indirect decays, assuming one coupling at a time to be non-zero. The limit holds for direct decays mediated by RPV $\mathit LQ\bar D$ couplings and improves to 90 GeV for indirect decays (for $\Delta \mathit m>$ 10 GeV). Limits are also given for $\mathit LL\bar E$ direct (${\mathit m}_{{{\widetilde{\mathit \mu}}}{{\mathit R}}}$ $>$ 87~GeV) and indirect decays (${\mathit m}_{{{\widetilde{\mathit \mu}}}{{\mathit R}}}$ $>$ 96 GeV for ${{\mathit m}}({{\widetilde{\mathit \chi}}_{{1}}^{0}}$) $>$ 23 GeV from BARATE 1998S) and for $\bar U \bar D \bar D$ indirect decays (${\mathit m}_{{{\widetilde{\mathit \mu}}}{{\mathit R}}}$ $>$ 85 GeV for $\Delta \mathit m>$ 10 GeV). Supersedes the results from BARATE 2001B.
EPJ C79 305 Search for resonant production of second-generation sleptons with same-sign dimuon events in proton-proton collisions at $\sqrt{s} =$ 13 TeV
PR D98 032009 Search for supersymmetry in events with four or more leptons in $\sqrt{s}=13$ TeV $pp$ collisions with ATLAS
AAD 2014X
PR D90 052001 Search for Supersymmetry in Events with Four or More Leptons in $\sqrt {s }$ = 8 TeV ${{\mathit p}}{{\mathit p}}$ Collisions with the ATLAS Detector
EPJ C36 1 Search for Supersymmetric Particles Assuming $\mathit R$-Parity non-conservation in ${{\mathit e}^{+}}{{\mathit e}^{-}}$ Collisions at $\sqrt {s }$ = 192 to 208 GeV
EPJ C31 1 Search for Supersymmetric Particles with $\mathit R$-Paryty Violating Decays in ${{\mathit e}^{+}}{{\mathit e}^{-}}$ Collisions at $\sqrt {s }$ up to 209 GeV