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.

Long-lived ${{\widetilde{\boldsymbol \ell}}}$ (Slepton) mass limit INSPIRE search

Limits on scalar leptons which leave detector before decaying. Limits from ${{\mathit Z}}$ decays are independent of lepton flavor. Limits from continuum ${{\mathit e}^{+}}{{\mathit e}^{-}}$ annihilation are also independent of flavor for smuons and staus. Selectron limits from ${{\mathit e}^{+}}{{\mathit e}^{-}}$ collisions in the continuum depend on MSSM parameters because of the additional neutralino exchange contribution.

VALUE (GeV) CL% DOCUMENT ID TECN  COMMENT
$> 430$ 95 1
AABOUD
2019AT
 ATLS long-lived ${{\widetilde{\mathit \tau}}}$, GMSB
$> 490$ 95 2
KHACHATRYAN
2016BW
 CMS long-lived ${{\widetilde{\mathit \tau}}}$ from inclusive production, mGMSB SPS line 7 scenario
$> 240$ 95 2
KHACHATRYAN
2016BW
 CMS long-lived ${{\widetilde{\mathit \tau}}}$ from direct pair production, mGMSB SPS line 7 scenario
$>440$ 95 3
AAD
2015AE
 ATLS mGMSB, $\mathit M_{mess}$ = 250 TeV, $\mathit N_{5}$ = 3, ${{\mathit \mu}}$ $>$ 0, $\mathit C_{grav}$ = 5000, tan ${{\mathit \beta}}$ = 10
$>385$ 95 3
AAD
2015AE
 ATLS mGMSB, $\mathit M_{mess}$ = 250 TeV, $\mathit N_{5}$ = 3, ${{\mathit \mu}}$ $>$ 0, $\mathit C_{grav}$ = 5000, tan ${{\mathit \beta}}$ = 50
$\bf{>286}$ 95 3
AAD
2015AE
 ATLS direct ${{\widetilde{\mathit \tau}}}$ production
$\text{none 124 - 309}$ 95 4
AAIJ
2015BD
 LHCB long-lived ${{\widetilde{\mathit \tau}}}$, mGMSB, SPS7
$>98$ 95 5
ABBIENDI
2003L
 OPAL ${{\widetilde{\mathit \mu}}_{{R}}}$, ${{\widetilde{\mathit \tau}}_{{R}}}$
$\text{ none 2 - 87.5}$ 95 6
ABREU
2000Q
 DLPH ${{\widetilde{\mathit \mu}}_{{R}}}$, ${{\widetilde{\mathit \tau}}_{{R}}}$
$>81.2$ 95 7
ACCIARRI
1999H
 L3 ${{\widetilde{\mathit \mu}}_{{R}}}$, ${{\widetilde{\mathit \tau}}_{{R}}}$
$>81$ 95 8
BARATE
1998K
 ALEP ${{\widetilde{\mathit \mu}}_{{R}}}$, ${{\widetilde{\mathit \tau}}_{{R}}}$
• • • We do not use the following data for averages, fits, limits, etc. • • •
$> 300$ 95 9
AAD
2013AA
 ATLS long-lived ${{\widetilde{\mathit \tau}}}$, GMSB, tan ${{\mathit \beta}}$ = $5 - 20$
10
ABAZOV
2013B
 D0 long-lived ${{\widetilde{\mathit \tau}}}$, 100 $<{\mathit m}_{{{\widetilde{\mathit \tau}}}}<$300 GeV
$> 339$ 95 11, 12
CHATRCHYAN
2013AB
 CMS long-lived ${{\widetilde{\mathit \tau}}}$, direct ${{\widetilde{\mathit \tau}}_{{1}}}$ pair prod., minimal GMSB, SPS line 7
$> 500$ 95 11, 13
CHATRCHYAN
2013AB
 CMS long-lived ${{\widetilde{\mathit \tau}}}$, ${{\widetilde{\mathit \tau}}_{{1}}}$ from direct pair prod. and from decay of heavier SUSY particles, minimal GMSB, SPS line 7
$> 314$ 95 14
CHATRCHYAN
2012L
 CMS long-lived ${{\widetilde{\mathit \tau}}}$, ${{\widetilde{\mathit \tau}}_{{1}}}$ from decay of heavier SUSY particles, minimal GMSB, SPS line 7
$> 136$ 95 15
AAD
2011P
 ATLS stable ${{\widetilde{\mathit \tau}}}$, GMSB scenario, tan ${{\mathit \beta}}$=5
1  AABOUD 2019AT searched in 36.1 ${\mathrm {fb}}{}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV for metastable and stable ${{\mathit R}}$-hadrons. Multiple search strategies for a wide range of lifetimes, corresponding to path lengths of a few meters, are defined. No significant deviations from the expected Standard Model background are observed. Results are interpreted in terms of exclusion limits on long-lived stau in the context of GMSB models. Lower limits on the mass for direct production of staus are set at 430 GeV, see their Fig. 10 (left).
2  KHACHATRYAN 2016BW searched in 2.5 ${\mathrm {fb}}{}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV for events with heavy stable charged particles, identified by their anomalously high energy deposits in the silicon tracker and/or long time-of-flight measurements by the muon system. No evidence for an excess over the expected background is observed. Limits are derived for pair production of tau sleptons as a function of mass, depending on their direct or inclusive production in a minimal GMSB scenario along the Snowmass Points and Slopes (SPS) line 7, see Fig. 4 and Table 7.
3  AAD 2015AE searched in 19.1 ${\mathrm {fb}}{}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 8 TeV for heavy long-lived charged particles, measured through their specific ionization energy loss in the ATLAS pixel detector or their time-of-flight in the ALTAS muon system. In the absence of an excess of events above the expected backgrounds, limits are set on stable ${{\widetilde{\mathit \tau}}}$ sleptons in various scenarios, see Figs. 5-7.
4  AAIJ 2015BD searched in 3.0 ${\mathrm {fb}}{}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 7 and 8 TeV for evidence of Drell-Yan pair production of long-lived ${{\widetilde{\mathit \tau}}}$ particles. No evidence for such particles is observed and 95$\%$ C.L. upper limits on the cross section of ${{\widetilde{\mathit \tau}}}$ pair production are derived, see Fig. 7. In the mGMSB, assuming the SPS7 benchmark scenario ${{\widetilde{\mathit \tau}}}$ masses between 124 and 309 GeV are excluded at 95$\%$ C.L.
5  ABBIENDI 2003L used ${{\mathit e}^{+}}{{\mathit e}^{-}}$ data at $\sqrt {s }$ = $130 - 209$ GeV to select events with two high momentum tracks with anomalous dE/dx. The excluded cross section is compared to the theoretical expectation as a function of the heavy particle mass in their Fig.~3. The limit improves to 98.5 GeV for ${{\widetilde{\mathit \mu}}_{{L}}}$ and ${{\widetilde{\mathit \tau}}_{{L}}}$. The bounds are valid for colorless spin 0 particles with lifetimes longer than $10^{-6}~$s. Supersedes the results from ACKERSTAFF 1998P.
6  ABREU 2000Q searches for the production of pairs of heavy, charged stable particles in ${{\mathit e}^{+}}{{\mathit e}^{-}}$ annihilation at $\sqrt {\mathit s }$= $130 - 189$ GeV. The upper bound improves to 88 GeV for ${{\widetilde{\mathit \mu}}_{{L}}}$, ${{\widetilde{\mathit \tau}}_{{L}}}$. These limits include and update the results of ABREU 1998P.
7  ACCIARRI 1999H searched for production of pairs of back-to-back heavy charged particles at $\sqrt {\mathit s }=130 - 183$ GeV. The upper bound improves to $82.2$ GeV for ${{\widetilde{\mathit \mu}}_{{L}}}$, ${{\widetilde{\mathit \tau}}_{{L}}}$.
8  The BARATE 1998K mass limit improves to 82 GeV for ${{\widetilde{\mathit \mu}}_{{L}}},{{\widetilde{\mathit \tau}}_{{L}}}$. Data collected at $\sqrt {\mathit s }=161 - 184$ GeV.
9  AAD 2013AA searched in 4.7 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 7 TeV for events containing long-lived massive particles in a GMSB framework. No significant excess above the expected background was found. A 95$\%$ C.L. lower limit of 300 GeV is placed on long-lived ${{\widetilde{\mathit \tau}}}$'s in the GMSB model with ${{\mathit M}_{{mess}}}$ = 250 TeV, ${{\mathit N}_{{S}}}$ = 3, ${{\mathit \mu}}$ $>$ 0, for tan ${{\mathit \beta}}$ = $5 - 20$. The lower limit on the GMSB breaking scale ${{\mathit \Lambda}}$ was found to be $99 - 110$ TeV, for tan ${{\mathit \beta}}$ values between 5 and 40, see Fig. 4 (top). Also, directly produced long-lived sleptons, or sleptons decaying to long-lived ones, are excluded at 95$\%$ C.L. up to a ${{\widetilde{\mathit \tau}}}$ mass of 278 GeV for models with slepton splittings smaller than 50 GeV.
10  ABAZOV 2013B looked in 6.3 fb${}^{-1}$ of ${{\mathit p}}{{\overline{\mathit p}}}$ collisions at $\sqrt {s }$ = 1.96 TeV for charged massive long-lived particles in events with muon-like particles that have both speed and ionization energy loss inconsistent with muons produced in beam collisions. In the absence of an excess, limits are set at 95$\%$ C.L. on the production cross section of stau leptons in the mass range $100 - 300$ GeV, see their Table 20 and Fig. 23.
11  CHATRCHYAN 2013AB looked in 5.0 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 7 TeV and in 18.8 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 8 TeV for events with heavy stable particles, identified by their anomalous dE/dx in the tracker or additionally requiring that it be identified as muon in the muon chambers, from pair production of ${{\widetilde{\mathit \tau}}_{{1}}}$'s. No evidence for an excess over the expected background is observed. Supersedes CHATRCHYAN 2012L.
12  CHATRCHYAN 2013AB limits are derived for pair production of ${{\widetilde{\mathit \tau}}_{{1}}}$ as a function of mass in minimal GMSB scenarios along the Snowmass Points and Slopes (SPS) line 7 (see Fig. 8 and Table 7). The limit given here is valid for direct pair ${{\widetilde{\mathit \tau}}_{{1}}}$ production.
13  CHATRCHYAN 2013AB limits are derived for the production of ${{\widetilde{\mathit \tau}}_{{1}}}$ as a function of mass in minimal GMSB scenarios along the Snowmass Points and Slopes (SPS) line 7 (see Fig. 8 and Table 7). The limit given here is valid for the production of ${{\widetilde{\mathit \tau}}_{{1}}}$ from both direct pair production and from the decay of heavier supersymmetric particles.
14  CHATRCHYAN 2012L looked in 5.0 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 7 TeV for events with heavy stable particles, identified by their anomalous dE/dx in the tracker or additionally requiring that it be identified as muon in the muon chambers, from pair production of ${{\widetilde{\mathit \tau}}_{{1}}}$'s. No evidence for an excess over the expected background is observed. Limits are derived for the production of ${{\widetilde{\mathit \tau}}_{{1}}}$ as a function of mass in minimal GMSB scenarios along the Snowmass Points and Slopes (SPS) line 7 (see Fig. 3). The limit given here is valid for the production of ${{\widetilde{\mathit \tau}}_{{1}}}$ in the decay of heavier supersymmetric particles.
15  AAD 2011P looked in 37 pb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 7 TeV for events with two heavy stable particles, reconstructed in the Inner tracker and the Muon System and identified by their time of flight in the Muon System. No evidence for an excess over the SM expectation is observed. Limits on the mass are derived, see Fig. 3, for ${{\widetilde{\mathit \tau}}}$ in a GMSB scenario and for sleptons produced by electroweak processes only, in which case the limit degrades to 110 GeV.
  References:
AABOUD 2019AT
PR D99 092007 Search for heavy charged long-lived particles in the ATLAS detector in 36.1 fb$^{-1}$ of proton-proton collision data at $\sqrt{s} = 13$ TeV
KHACHATRYAN 2016BW
PR D94 112004 Search for Long-Lived Charged Particles in Proton-Proton Collisions at $\sqrt {s }$ = 13 TeV
AAD 2015AE
JHEP 1501 068 Searches for Heavy Long-Lived Charged Particles with the ATLAS Detector in Proton-Proton Collisions at $\sqrt {s }$ = 8 TeV
AAIJ 2015BD
EPJ C75 595 Search for Long-Lived Heavy Charged Particles using a Ring Imaging Cherenkov Technique at LHCb
AAD 2013AA
PL B720 277 Searches for Heavy Long-Lived Sleptons and $\mathit R$-Hadrons with the ATLAS Detector in ${{\mathit p}}{{\mathit p}}$ Collisions at $\sqrt {s }$ = 7 TeV
ABAZOV 2013B
PR D87 052011 Search for Charged Massive Long-Lived Particles at $\sqrt {s }$ = 1.96 TeV
CHATRCHYAN 2013AB
JHEP 1307 122 Searches for Long-Lived Charged Particles in ${{\mathit p}}{{\mathit p}}$ Collisions at $\sqrt {s }$ = 7 and 8 TeV
CHATRCHYAN 2012L
PL B713 408 Search for Heavy Long-Lived Charged Particles in ${{\mathit p}}{{\mathit p}}$ Collisions at $\sqrt {s }$ = 7 TeV
AAD 2011P
PL B703 428 Search for Heavy Long-Lived Charged Particles with the ATLAS Detector in ${{\mathit p}}{{\mathit p}}$ Collisions at $\sqrt {s }$ = 7 TeV
ABBIENDI 2003L
PL B572 8 Search for Stable and Longlived Massive Charged Particles in ${{\mathit e}^{+}}{{\mathit e}^{-}}$ Collisions at $\sqrt {s }$ = 130 to 209 GeV
ABREU 2000Q
PL B478 65 Search for Heavy Stable and Longlived Particles in ${{\mathit e}^{+}}{{\mathit e}^{-}}$ Collisions at $\sqrt {s }$ = 189 GeV
ACCIARRI 1999H
PL B456 283 Search for Scalar Leptons in ${{\mathit e}^{+}}{{\mathit e}^{-}}$ Collisions at $\sqrt {s }$ = 183 GeV
BARATE 1998K
PL B433 176 Search for Sleptons in ${{\mathit e}^{+}}{{\mathit e}^{-}}$ Collisions at Centre-of-Mass Energies up to 184 GeV