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Displaced Leptons andOther Exotic Objects at the LHC
Jared A. Evansjaredaevans@gmail.com
Department of PhysicsUniversity of Illinois, Urbana-Champaign
Evans, Shelton – arXiv:1601.01326
Evans (UIUC) Displaced Leptons February 16, 2016 1 / 39
Outline
Status of LHC Exotic Objects
Displaced Leptons from τRs in Gauge MediationHSCP Searches (CMS)Disappearing Tracks Searches (ATLAS & CMS)CMS Displaced eµ SearchRecast LimitsPaths for Improvements
A Gap: Same-Flavor Displaced LeptonsModels: co-NLSPs, EGMSB, RPV, freezein dark matterA Same-Flavor Displaced Lepton Search for 13 TeV
Comments and Perspectives
Evans (UIUC) Displaced Leptons February 16, 2016 2 / 39
The LHC Program
The LHC has constrained many new particles in many models
I MSSMI t ′/b′
I UEDI GMSBI RPVI StealthI 2HDMI ...
Signature Space
These searches cast a wide net
– but there are gaps
Need comprehensive program that covers ALL new physics scenarios
An exotic object could be our pathway to BSM physics!
Evans (UIUC) Displaced Leptons February 16, 2016 3 / 39
The LHC Program
The LHC has constrained many new particles in many models
I MSSMI t ′/b′
I UEDI GMSBI RPVI StealthI 2HDMI ...
Signature Space
These searches cast a wide net – but there are gaps
Need comprehensive program that covers ALL new physics scenarios
An exotic object could be our pathway to BSM physics!
Evans (UIUC) Displaced Leptons February 16, 2016 3 / 39
The LHC Program
The LHC has constrained many new particles in many models
I MSSMI t ′/b′
I UEDI GMSBI RPVI StealthI 2HDMI ...
Signature Space
These searches cast a wide net – but there are gaps
Need comprehensive program that covers ALL new physics scenarios
An exotic object could be our FIRST pathway to BSM physics!Evans (UIUC) Displaced Leptons February 16, 2016 3 / 39
The LHC Program
The LHC has constrained many new particles in many models
I MSSMI t ′/b′
I UEDI GMSBI RPVI StealthI 2HDMI ...
Signature Space
These searches cast a wide net – but there are gaps
Need comprehensive program that covers ALL new physics scenarios
An exotic object could be our ONLY pathway to BSM physics!!!Evans (UIUC) Displaced Leptons February 16, 2016 3 / 39
What are Exotic Objects?
Object Very Rough Identification Criteria
1) Photon Hard, isolated EM calo deposit, Etracks Ecalo
2) Electron Hard, isolated EM calo deposit, Etrack ∼ Ecalo
3) Muon Hard, isolated track through muon chamber4) Jet Other hard calo/track/particle clusters
a) Tau Single or 3-prong hard, isolated track(s)b) b-jet Secondary vertex, looks b-ish
5) ~E/T −∑~pT
Evans (UIUC) Displaced Leptons February 16, 2016 4 / 39
What are Standard Objects?
Object Very Rough Identification Criteria
1) Photon Hard, isolated EM calo deposit, Etracks Ecalo
2) Electron Hard, isolated EM calo deposit, Etrack ∼ Ecalo
3) Muon Hard, isolated track through muon chamber4) Jet Other hard calo/track/particle clusters
a) Tau Single or 3-prong hard, isolated track(s)b) b-jet Secondary vertex, looks b-ish
5) ~E/T −∑~pT
Evans (UIUC) Displaced Leptons February 16, 2016 4 / 39
What are Standard Objects?Object Very Rough Identification Criteria
1) Photon Hard, isolated EM calo deposit, Etracks Ecalo
2) Electron Hard, isolated EM calo deposit, Etrack ∼ Ecalo
3) Muon Hard, isolated track through muon chamber4) Jet Other hard calo/track/particle clusters
a) Tau Single or 3-prong hard, isolated track(s)b) b-jet Secondary vertex, looks b-ish
5) ~E/T −∑~pT
Evans (UIUC) Displaced Leptons February 16, 2016 4 / 39
What are Exotic Objects?Object Very Rough Identification Criteria
1) Photon Hard, isolated EM calo deposit, Etracks Ecalo
2) Electron Hard, isolated EM calo deposit, Etrack ∼ Ecalo
3) Muon Hard, isolated track through muon chamber4) Jet Other hard calo/track/particle clusters
a) Tau Single or 3-prong hard, isolated track(s)b) b-jet Secondary vertex, looks b-ish
5) ~E/T −∑~pT
Loaded words: track, isolated, hard, cluster, vertex, b-ish ...
Exotic objects have properties that allow them to bedistinguished from these standard objects
Two basic classes: Direct & Indirect
Evans (UIUC) Displaced Leptons February 16, 2016 4 / 39
What are Exotic Objects?Object Very Rough Identification Criteria
1) Photon Hard, isolated EM calo deposit, Etracks Ecalo
2) Electron Hard, isolated EM calo deposit, Etrack ∼ Ecalo
3) Muon Hard, isolated track through muon chamber4) Jet Other hard calo/track/particle clusters
a) Tau Single or 3-prong hard, isolated track(s)b) b-jet Secondary vertex, looks b-ish
5) ~E/T −∑~pT
Loaded words: track, isolated, hard, cluster, vertex, b-ish ...
Exotic objects have properties that allow them to bedistinguished from these standard objects
Two basic classes: Direct & Indirect
Evans (UIUC) Displaced Leptons February 16, 2016 4 / 39
What are Exotic Objects?Direct vs Indirect
Direct
Observe the object itself
Examples:Disappearing tracks
Heavy, stable, charged particlesMagnetic monopoles
R-hadronsQuirks
. . .
LHC searches exist
q qqqqqqqqqqqqqq qqqqqqqqqqqqq qqqqqqqqqqqq qqqqqqqqqqq qqqqqqqqqq qqqqqqqqq qqqqqqqq qqqqqqq qqqqqq qqqqqq qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq qqqqqq qqqqqqq qqqqqqqq qqqqqqqqq qqqqqqqqqq qqqqqqqqqqq qqqqqqqqqqqq qqqqqqqqqqqqq qqqqqqqqqqqqqq
Indirect
Observe atypical SM decay products
Collimated particles fail isolationNon-isolated leptons/photons
Photon or lepton jets
Particles that decay in flightLong lifetime from an approximatesymmetry in the low energy theory
High dimension operatorsHigh mass scaleSmall couplings
Evans (UIUC) Displaced Leptons February 16, 2016 5 / 39
What are Exotic Objects?Direct vs Indirect
Direct
Observe the object itself
Examples:Disappearing tracks
Heavy, stable, charged particlesMagnetic monopoles
R-hadronsQuirks
. . .
LHC searches exist
q qqqqqqqqqqqqqq qqqqqqqqqqqqq qqqqqqqqqqqq qqqqqqqqqqq qqqqqqqqqq qqqqqqqqq qqqqqqqq qqqqqqq qqqqqq qqqqqq qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq qqqqqq qqqqqqq qqqqqqqq qqqqqqqqq qqqqqqqqqq qqqqqqqqqqq qqqqqqqqqqqq qqqqqqqqqqqqq qqqqqqqqqqqqqq
Indirect
Observe atypical SM decay products
Collimated particles fail isolationNon-isolated leptons/photons
Photon or lepton jets
Particles that decay in flightLong lifetime from an approximatesymmetry in the low energy theory
High dimension operatorsHigh mass scaleSmall couplings
Evans (UIUC) Displaced Leptons February 16, 2016 5 / 39
What are Exotic Objects?Direct vs Indirect
Direct
Observe the object itself
Examples:Disappearing tracks
Heavy, stable, charged particlesMagnetic monopoles
R-hadronsQuirks
. . .
LHC searches exist
q qqqqqqqqqqqqqq qqqqqqqqqqqqq qqqqqqqqqqqq qqqqqqqqqqq qqqqqqqqqq qqqqqqqqq qqqqqqqq qqqqqqq qqqqqq qqqqqq qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq qqqqqq qqqqqqq qqqqqqqq qqqqqqqqq qqqqqqqqqq qqqqqqqqqqq qqqqqqqqqqqq qqqqqqqqqqqqq qqqqqqqqqqqqqq
Indirect
Observe atypical SM decay products
Collimated particles fail isolationNon-isolated leptons/photons
Photon or lepton jets
Particles that decay in flightLong lifetime from an approximatesymmetry in the low energy theory
High dimension operatorsHigh mass scaleSmall couplings
Evans (UIUC) Displaced Leptons February 16, 2016 5 / 39
What are Exotic Objects?Direct vs Indirect
Direct
Observe the object itself
Examples:Disappearing tracks
Heavy, stable, charged particlesMagnetic monopoles
R-hadronsQuirks
. . .
LHC searches exist
q qqqqqqqqqqqqqq qqqqqqqqqqqqq qqqqqqqqqqqq qqqqqqqqqqq qqqqqqqqqq qqqqqqqqq qqqqqqqq qqqqqqq qqqqqq qqqqqq qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq qqqqqq qqqqqqq qqqqqqqq qqqqqqqqq qqqqqqqqqq qqqqqqqqqqq qqqqqqqqqqqq qqqqqqqqqqqqq qqqqqqqqqqqqqq
Indirect
Observe atypical SM decay products
Collimated particles fail isolationNon-isolated leptons/photons
Photon or lepton jets
Particles that decay in flightLong lifetime from an approximatesymmetry in the low energy theory
High dimension operatorsHigh mass scaleSmall couplings
Evans (UIUC) Displaced Leptons February 16, 2016 5 / 39
What are Exotic Objects?Direct vs Indirect
Direct
Observe the object itself
Examples:Disappearing tracks
Heavy, stable, charged particlesMagnetic monopoles
R-hadronsQuirks
. . .
LHC searches exist
q qqqqqqqqqqqqqq qqqqqqqqqqqqq qqqqqqqqqqqq qqqqqqqqqqq qqqqqqqqqq qqqqqqqqq qqqqqqqq qqqqqqq qqqqqq qqqqqq qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq qqqqqq qqqqqqq qqqqqqqq qqqqqqqqq qqqqqqqqqq qqqqqqqqqqq qqqqqqqqqqqq qqqqqqqqqqqqq qqqqqqqqqqqqqq
Indirect
Observe atypical SM decay products
Collimated particles fail isolationNon-isolated leptons/photons
Photon or lepton jets
Particles that decay in flightLong lifetime from an approximatesymmetry in the low energy theory
High dimension operatorsHigh mass scaleSmall couplings
Evans (UIUC) Displaced Leptons February 16, 2016 5 / 39
Long-lived / Displaced in SUSY
CMS dijetATLAS µ spect
LHC8 projection
charged stable
charge-stripped
ATLAS HCAL
t ! d s (RPV)~ _ _
prompt paireddijets
jet substructure(projection)
Liu, Tweedie – 2015
Many displaced decays are well-covered: Most RPVLiu, Tweedie – 2015Csaki, Kuflik, Lombardo, Slone, Volansky – 2015 Zwane – 2015
Evans (UIUC) Displaced Leptons February 16, 2016 6 / 39
Long-lived / Displaced in SUSY
CMS dijetATLAS µ spect
LHC8 projection
charged stable
charge-stripped
ATLAS HCAL
g ! j j j (RPV)~
prompt 3j resonance
Liu, Tweedie – 2015
Many displaced decays are well-covered: Most RPVLiu, Tweedie – 2015Csaki, Kuflik, Lombardo, Slone, Volansky – 2015 Zwane – 2015
Evans (UIUC) Displaced Leptons February 16, 2016 6 / 39
Long-lived / Displaced in SUSY
CMS dijet
ATLAS µ spect
LHC8 projection
ATLAS HCAL
a) H ! Z G (GMSB)~ ~
prompt Higgsino
ATLAS µ+tracksCMS e & µ
CMS dilepton
Liu, Tweedie – 2015
Many displaced decays are well-covered: Most GMSBLiu, Tweedie – 2015
Evans (UIUC) Displaced Leptons February 16, 2016 6 / 39
Long-lived / Displaced in SUSY
ATLAS µ spect
LHC8 projection
charged stable
charge-stripped
prompt jets + MET
ATLAS HCAL
a) g ! q q B, m(B) = 0 (mini-split)~ ~
CMS dijet
~
CMS stopped gluino
ATLAS promptjets + MET recast
(approx)
Liu, Tweedie – 2015
Many displaced decays are well-covered: Mini-SplitLiu, Tweedie – 2015 Coverage exceeds prompt signatures!
Evans (UIUC) Displaced Leptons February 16, 2016 6 / 39
Displaced Objects: pp → XX , X → o1o2(o3)Searches
o2o1 j b γ e µ τ E/Tj
jj/dv jj/dv jj/dv/dA jj/dv jj/dv jj/dv/em jj/dv
b X
jj/dv jj/dv/dA jj/dv jj/dv jj/dv/em jj/dv
γ X X
dA dA dA dA/em dA
e X X X
dv/ll dv dv/ll
µ X X X X
dv/ll dv/ll
τ X X X X X
dv/ll/em emq qqqqq qqqqq qqqqq qqqqq qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq qqqqq qqqqq qqqqq qqqqq
Search arXiv Symbol Comments
CMS Displaced Dijets 1411.6530 jj mX > 50 GeVATLAS Displaced Vertex 1504.05162 dv mX > 10 GeVCMS Displaced Dilepton 1411.6977 ll mX > 15 GeVATLAS Delayed Photon 1409.5542 dA mX & 100 GeV
CMS Displaced eµ 1409.4789 em Best at LFU
I Focused on pair produced, heavy decays inside the detectorI Only a selection of searches used, but fairly representativeI Cavalier about lifetime ranges and triggers; ignoring topsI Bold is where searches are really optimized
Evans (UIUC) Displaced Leptons February 16, 2016 7 / 39
Displaced Objects: pp → XX , X → o1o2(o3)Searches
o2o1 j b γ e µ τ E/Tj jj
/dv
jj
/dv
jj
/dv/dA
jj
/dv
jj
/dv
jj
/dv/em
jj
/dv
b X jj
/dv
jj
/dv/dA
jj
/dv
jj
/dv
jj
/dv/em
jj
/dv
γ X X
dA dA dA dA/em dA
e X X X
dv/ll dv dv/ll
µ X X X X
dv/ll dv/ll
τ X X X X X
dv/ll/em emq qqqqq qqqqq qqqqq qqqqq qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq qqqqq qqqqq qqqqq qqqqq
Search arXiv Symbol CommentsCMS Displaced Dijets 1411.6530 jj mX > 50 GeV
ATLAS Displaced Vertex 1504.05162 dv mX > 10 GeVCMS Displaced Dilepton 1411.6977 ll mX > 15 GeVATLAS Delayed Photon 1409.5542 dA mX & 100 GeV
CMS Displaced eµ 1409.4789 em Best at LFU
Evans (UIUC) Displaced Leptons February 16, 2016 7 / 39
Displaced Objects: pp → XX , X → o1o2(o3)Searches
o2o1 j b γ e µ τ E/Tj jj/dv jj/dv jj/dv
/dA
jj/dv jj/dv jj/dv
/em
jj/dvb X jj/dv jj/dv
/dA
jj/dv jj/dv jj/dv
/em
jj/dvγ X X
dA dA dA dA/em dA
e X X X dv
/ll
dv dv
/ll
µ X X X X dv
/ll
dv
/ll
τ X X X X X dv
/ll/em emq qqqqq qqqqq qqqqq qqqqq qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq qqqqq qqqqq qqqqq qqqqq
Search arXiv Symbol CommentsCMS Displaced Dijets 1411.6530 jj mX > 50 GeV
ATLAS Displaced Vertex 1504.05162 dv mX > 10 GeV
CMS Displaced Dilepton 1411.6977 ll mX > 15 GeVATLAS Delayed Photon 1409.5542 dA mX & 100 GeV
CMS Displaced eµ 1409.4789 em Best at LFU
Evans (UIUC) Displaced Leptons February 16, 2016 7 / 39
Displaced Objects: pp → XX , X → o1o2(o3)Searches
o2o1 j b γ e µ τ E/Tj jj/dv jj/dv jj/dv
/dA
jj/dv jj/dv jj/dv
/em
jj/dvb X jj/dv jj/dv
/dA
jj/dv jj/dv jj/dv
/em
jj/dvγ X X
dA dA dA dA/em dA
e X X X dv/ll dv dv/llµ X X X X dv/ll dv/llτ X X X X X dv/ll
/em emq qqqqq qqqqq qqqqq qqqqq qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq qqqqq qqqqq qqqqq qqqqq
Search arXiv Symbol CommentsCMS Displaced Dijets 1411.6530 jj mX > 50 GeV
ATLAS Displaced Vertex 1504.05162 dv mX > 10 GeVCMS Displaced Dilepton 1411.6977 ll mX > 15 GeV
ATLAS Delayed Photon 1409.5542 dA mX & 100 GeVCMS Displaced eµ 1409.4789 em Best at LFU
Evans (UIUC) Displaced Leptons February 16, 2016 7 / 39
Displaced Objects: pp → XX , X → o1o2(o3)Searches
o2o1 j b γ e µ τ E/Tj jj/dv jj/dv jj/dv/dA jj/dv jj/dv jj/dv
/em
jj/dvb X jj/dv jj/dv/dA jj/dv jj/dv jj/dv
/em
jj/dvγ X X dA dA dA dA
/em
dAe X X X dv/ll dv dv/llµ X X X X dv/ll dv/llτ X X X X X dv/ll
/em emq qqqqq qqqqq qqqqq qqqqq qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq qqqqq qqqqq qqqqq qqqqq
Search arXiv Symbol CommentsCMS Displaced Dijets 1411.6530 jj mX > 50 GeV
ATLAS Displaced Vertex 1504.05162 dv mX > 10 GeVCMS Displaced Dilepton 1411.6977 ll mX > 15 GeVATLAS Delayed Photon 1409.5542 dA mX & 100 GeV
CMS Displaced eµ 1409.4789 em Best at LFU
Evans (UIUC) Displaced Leptons February 16, 2016 7 / 39
Displaced Objects: pp → XX , X → o1o2(o3)Searches
o2o1 j b γ e µ τ E/Tj jj/dv jj/dv jj/dv/dA jj/dv jj/dv jj/dv/em jj/dvb X jj/dv jj/dv/dA jj/dv jj/dv jj/dv/em jj/dvγ X X dA dA dA dA/em dAe X X X dv/ll dv dv/llµ X X X X dv/ll dv/llτ X X X X X dv/ll/em em
q qqqqq qqqqq qqqqq qqqqq qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq qqqqq qqqqq qqqqq qqqqq
Search arXiv Symbol CommentsCMS Displaced Dijets 1411.6530 jj mX > 50 GeV
ATLAS Displaced Vertex 1504.05162 dv mX > 10 GeVCMS Displaced Dilepton 1411.6977 ll mX > 15 GeVATLAS Delayed Photon 1409.5542 dA mX & 100 GeV
CMS Displaced eµ 1409.4789 em Best at LFU
Evans (UIUC) Displaced Leptons February 16, 2016 7 / 39
Displaced Objects: pp → XX , X → o1o2(o3)Searches
o2o1 j b γ e µ τ E/Tj jj/dv jj/dv jj/dv/dA jj/dv jj/dv jj/dv/em jj/dvb X jj/dv jj/dv/dA jj/dv jj/dv jj/dv/em jj/dvγ X X dA dA dA dA/em dAe X X X dv/ll dv dv/llµ X X X X dv/ll dv/llτ X X X X X dv/ll/em emq qqqqq qqqqq qqqqq qqqqq qqqqqqqqqqqqq
qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq qqqqq qqqqq qqqqq qqqqq
Search arXiv Symbol CommentsCMS Displaced Dijets 1411.6530 jj mX > 50 GeV
ATLAS Displaced Vertex 1504.05162 dv mX > 10 GeVCMS Displaced Dilepton 1411.6977 ll mX > 15 GeVATLAS Delayed Photon 1409.5542 dA mX & 100 GeV
CMS Displaced eµ 1409.4789 em Best at LFU
Evans (UIUC) Displaced Leptons February 16, 2016 7 / 39
Displaced Objects: pp → XX , X → o1o2(o3)Models
o2o1 j b γ e µ τ E/Tj
MGRSγ R R R R MGRD
b X
MGRSHγ R R R MGRD
γ X X
S G
e X X X
GRγ R R GRD
µ X X X X
GRHγ R GRD
τ X X X X X
GRHγ GRDq qqqqqq qqqqqq qqqqq qqqqq qqqqq qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq qqqqq qqqqq qqqqq qqqqqq qqqqqq
Models Symbol
Mini-Split MGMSB G
RPV/dRPV RStealth S
Higgs Mixed HDark Photon γ
MD Freezein Dark Matter D
Well-motivated Theoretically
Weak Coverage Experimentally
Evans (UIUC) Displaced Leptons February 16, 2016 8 / 39
Displaced Objects: pp → XX , X → o1o2(o3)Models
o2o1 j b γ e µ τ E/Tj M
GRSγ R R R R
M
GRD
b X M
GRSHγ R R R
M
GRD
γ X X
S G
e X X X
GRγ R R GRD
µ X X X X
GRHγ R GRD
τ X X X X X
GRHγ GRDq qqqqqq qqqqqq qqqqq qqqqq qqqqq qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq qqqqq qqqqq qqqqq qqqqqq qqqqqq
Models SymbolMini-Split M
GMSB GRPV/dRPV R
Stealth SHiggs Mixed HDark Photon γ
MD Freezein Dark Matter D
Well-motivated Theoretically
Weak Coverage Experimentally
Evans (UIUC) Displaced Leptons February 16, 2016 8 / 39
Displaced Objects: pp → XX , X → o1o2(o3)Models
o2o1 j b γ e µ τ E/Tj MG
RSγ R R R R
MG
RD
b X MG
RSHγ R R R
MG
RD
γ X X
S
Ge X X X G
Rγ R R
G
RD
µ X X X X G
RHγ R
G
RD
τ X X X X X G
RHγ
G
RDq qqqqqq qqqqqq qqqqq qqqqq qqqqq qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq qqqqq qqqqq qqqqq qqqqqq qqqqqq
Models SymbolMini-Split M
GMSB G
RPV/dRPV RStealth S
Higgs Mixed HDark Photon γ
MD Freezein Dark Matter D
Well-motivated Theoretically
Weak Coverage Experimentally
Evans (UIUC) Displaced Leptons February 16, 2016 8 / 39
Displaced Objects: pp → XX , X → o1o2(o3)Models
o2o1 j b γ e µ τ E/Tj MGR
Sγ
R R R R MGR
D
b X MGR
SHγ
R R R MGR
D
γ X X
S
Ge X X X GR
γ
R R GR
D
µ X X X X GR
Hγ
R GR
D
τ X X X X X GR
Hγ
GR
Dq qqqqqq qqqqqq qqqqq qqqqq qqqqq qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq qqqqq qqqqq qqqqq qqqqqq qqqqqq
Models SymbolMini-Split M
GMSB GRPV/dRPV R
Stealth SHiggs Mixed HDark Photon γ
MD Freezein Dark Matter D
Well-motivated Theoretically
Weak Coverage Experimentally
Evans (UIUC) Displaced Leptons February 16, 2016 8 / 39
Displaced Objects: pp → XX , X → o1o2(o3)Models
o2o1 j b γ e µ τ E/Tj MGRS
γ
R R R R MGR
D
b X MGRS
Hγ
R R R MGR
D
γ X X S Ge X X X GR
γ
R R GR
D
µ X X X X GR
Hγ
R GR
D
τ X X X X X GR
Hγ
GR
Dq qqqqqq qqqqqq qqqqq qqqqq qqqqq qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq qqqqq qqqqq qqqqq qqqqqq qqqqqq
Models SymbolMini-Split M
GMSB GRPV/dRPV R
Stealth S
Higgs Mixed HDark Photon γ
MD Freezein Dark Matter D
Well-motivated Theoretically
Weak Coverage Experimentally
Evans (UIUC) Displaced Leptons February 16, 2016 8 / 39
Displaced Objects: pp → XX , X → o1o2(o3)Models
o2o1 j b γ e µ τ E/Tj MGRS
γ
R R R R MGR
D
b X MGRSH
γ
R R R MGR
D
γ X X S Ge X X X GR
γ
R R GR
D
µ X X X X GRH
γ
R GR
D
τ X X X X X GRH
γ
GR
Dq qqqqqq qqqqqq qqqqq qqqqq qqqqq qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq qqqqq qqqqq qqqqq qqqqqq qqqqqq
Models SymbolMini-Split M
GMSB GRPV/dRPV R
Stealth SHiggs Mixed H
Dark Photon γMD Freezein Dark Matter D
Well-motivated Theoretically
Weak Coverage Experimentally
Evans (UIUC) Displaced Leptons February 16, 2016 8 / 39
Displaced Objects: pp → XX , X → o1o2(o3)Models
o2o1 j b γ e µ τ E/Tj MGRSγ R R R R MGR
D
b X MGRSHγ R R R MGR
D
γ X X S Ge X X X GRγ R R GR
D
µ X X X X GRHγ R GR
D
τ X X X X X GRHγ GR
Dq qqqqqq qqqqqq qqqqq qqqqq qqqqq qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq qqqqq qqqqq qqqqq qqqqqq qqqqqq
Models SymbolMini-Split M
GMSB GRPV/dRPV R
Stealth SHiggs Mixed HDark Photon γ
MD Freezein Dark Matter D
Well-motivated Theoretically
Weak Coverage Experimentally
Evans (UIUC) Displaced Leptons February 16, 2016 8 / 39
Displaced Objects: pp → XX , X → o1o2(o3)Models
o2o1 j b γ e µ τ E/Tj MGRSγ R R R R MGRDb X MGRSHγ R R R MGRDγ X X S Ge X X X GRγ R R GRDµ X X X X GRHγ R GRDτ X X X X X GRHγ GRD
q qqqqqq qqqqqq qqqqq qqqqq qqqqq qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq qqqqq qqqqq qqqqq qqqqqq qqqqqq
Models SymbolMini-Split M
GMSB GRPV/dRPV R
Stealth SHiggs Mixed HDark Photon γ
MD Freezein Dark Matter D
Well-motivated Theoretically
Weak Coverage Experimentally
Evans (UIUC) Displaced Leptons February 16, 2016 8 / 39
Displaced Objects: pp → XX , X → o1o2(o3)Models
o2o1 j b γ e µ τ E/Tj MGRSγ R R R R MGRDb X MGRSHγ R R R MGRDγ X X S Ge X X X GRγ R R GRDµ X X X X GRHγ R GRDτ X X X X X GRHγ GRDq qqqqqq qqqqqq qqqqq qqqqq qqqqq qqqqqqqqqqqqq
qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq qqqqq qqqqq qqqqq qqqqqq qqqqqq
Models SymbolMini-Split M
GMSB GRPV/dRPV R
Stealth SHiggs Mixed HDark Photon γ
MD Freezein Dark Matter D
Well-motivated Theoretically
Weak Coverage Experimentally
Evans (UIUC) Displaced Leptons February 16, 2016 8 / 39
Displaced Leptons in Prompt Searches
Prompt lepton-based searches:I Quality criteria drop displaced electrons
I Displaced muons veto events (cosmics)
I Vetoes range from 50 µm–1 mm
Prompt jets+E/T searches:I Veto events with leptons
I Definition not always transparent
Very dangerous region!
pp → ˜+ ˜− + X → displaced muons+ Xlives in a prompt search blind spot!
Displaced electrons and taus⇒ reduced efficiency
Evans (UIUC) Displaced Leptons February 16, 2016 9 / 39
Displaced Leptons in Prompt Searches
Prompt lepton-based searches:I Quality criteria drop displaced electrons
I Displaced muons veto events (cosmics)
I Vetoes range from 50 µm–1 mm
Prompt jets+E/T searches:I Veto events with leptons
I Definition not always transparent
Very dangerous region!
pp → ˜+ ˜− + X → displaced muons+ Xlives in a prompt search blind spot!
Displaced electrons and taus⇒ reduced efficiencyEvans (UIUC) Displaced Leptons February 16, 2016 9 / 39
Gauge Mediation and τR NLSPsLightning Review of Minimal GMSB
q qqqqqqqq qqqqqqq qqqqqqq qqqqqq qqqqqq qqqqqq qqqqqqq qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq qqqqqqq qqqqqq
qqqqqq qqqqqq qqqqqqq qqqqqqq qqqqqqqq
q qqqqqqqq qqqqqqq qqqqqqq qqqqqq qqqqqq qqqqqq qqqqqqq qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq qqqqqqq qqqqqq
qqqqqq qqqqqq qqqqqqq qqqqqqq qqqqqqqq. ........................................... ........................................ ..................................... .................................. .............................. ........................... ........................ ..................... .................. ............... ............ ........ ..... ..
MSSMQ, U, Hu
L, etc
Messengers, Φ SUSY... ..... ........ ............ ............... .................. ..................... ........................
X
W ∼ XΦΦ + MSSM yukawas〈X 〉 = M + θ2F , Λ ≡ F/M, Λ ≡ Λ
16π2
Mr ∼ Neff g2r Λ A-terms = 0
m2soft ∼ 2Neff Cr g4
r Λ2 (Cr quadratic Casimirs O (1))
Potential NLSP Masses:
mB = Neff g2
1 Λ Neff ≥ 2⇒ τR NLSP
m˜R=√
6Neff5 g2
1 Λ (or large running)
Evans (UIUC) Displaced Leptons February 16, 2016 10 / 39
Gauge Mediation and τR NLSPsLightning Review of Minimal GMSB
q qqqqqqqq qqqqqqq qqqqqqq qqqqqq qqqqqq qqqqqq qqqqqqq qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq qqqqqqq qqqqqq
qqqqqq qqqqqq qqqqqqq qqqqqqq qqqqqqqq
q qqqqqqqq qqqqqqq qqqqqqq qqqqqq qqqqqq qqqqqq qqqqqqq qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq qqqqqqq qqqqqq
qqqqqq qqqqqq qqqqqqq qqqqqqq qqqqqqqq. ........................................... ........................................ ..................................... .................................. .............................. ........................... ........................ ..................... .................. ............... ............ ........ ..... ..
MSSMQ, U, Hu
L, etc
Messengers, Φ SUSY... ..... ........ ............ ............... .................. ..................... ........................
X
W ∼ XΦΦ + MSSM yukawas〈X 〉 = M + θ2F , Λ ≡ F/M, Λ ≡ Λ
16π2
Mr ∼ Neff g2r Λ A-terms = 0
m2soft ∼ 2Neff Cr g4
r Λ2 (Cr quadratic Casimirs O (1))
Potential NLSP Masses:
mB = Neff g2
1 Λ Neff ≥ 2⇒ τR NLSP
m˜R=√
6Neff5 g2
1 Λ (or large running)
Evans (UIUC) Displaced Leptons February 16, 2016 10 / 39
Gauge Mediation and τR NLSPsLightning Review of Minimal GMSB
q qqqqqqqq qqqqqqq qqqqqqq qqqqqq qqqqqq qqqqqq qqqqqqq qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq qqqqqqq qqqqqq
qqqqqq qqqqqq qqqqqqq qqqqqqq qqqqqqqq
q qqqqqqqq qqqqqqq qqqqqqq qqqqqq qqqqqq qqqqqq qqqqqqq qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq qqqqqqq qqqqqq
qqqqqq qqqqqq qqqqqqq qqqqqqq qqqqqqqq. ........................................... ........................................ ..................................... .................................. .............................. ........................... ........................ ..................... .................. ............... ............ ........ ..... ..
MSSMQ, U, Hu
L, etc
Messengers, Φ SUSY... ..... ........ ............ ............... .................. ..................... ........................
X
W ∼ XΦΦ + MSSM yukawas〈X 〉 = M + θ2F , Λ ≡ F/M, Λ ≡ Λ
16π2
Mr ∼ Neff g2r Λ A-terms = 0
m2soft ∼ 2Neff Cr g4
r Λ2 (Cr quadratic Casimirs O (1))
Potential NLSP Masses:
mB = Neff g2
1 Λ Neff ≥ 2⇒ τR NLSP
m˜R=√
6Neff5 g2
1 Λ (or large running)
Evans (UIUC) Displaced Leptons February 16, 2016 10 / 39
Gauge Mediation and τR NLSPsLifetimes
GMSB is a very well-motivated source of displaced particles
cτ ≈ 100µm(
100 GeVmτ
)5( √
F100 TeV
)4
What is√
F?
F < M2; otherwise arbitrary
cτ ∼ 10µm(
100 GeVmτ
)(M√F
)4 1N2
eff(minimal GM only)
LHC relevant range: 100µm . cτ . 1 m
Measuring mτR & cττR probes SUSY breaking!
Evans (UIUC) Displaced Leptons February 16, 2016 11 / 39
Gauge Mediation and τR NLSPsLifetimes
GMSB is a very well-motivated source of displaced particles
cτ ≈ 100µm(
100 GeVmτ
)5( √
F100 TeV
)4
What is√
F?
F < M2; otherwise arbitrary
cτ ∼ 10µm(
100 GeVmτ
)(M√F
)4 1N2
eff(minimal GM only)
LHC relevant range: 100µm . cτ . 1 m
Measuring mτR & cττR probes SUSY breaking!
Evans (UIUC) Displaced Leptons February 16, 2016 11 / 39
Gauge Mediation and τR NLSPsLEP Limits on Slepton NLSPs OPAL
50
60
70
80
90
100
-12 -10 -8 -6log(τlife/s)
m(τ∼
1) (G
eV/c
2 )
50
60
70
80
90
100
-12 -10 -8 -6
a) τ∼
1 (τ∼
1 NLSP)
50
60
70
80
90
100
-12 -10 -8 -6log(τlife/s)
m(µ∼
R) (
GeV
/c2 )
50
60
70
80
90
100
-12 -10 -8 -6
b) µ∼
R (l∼
R co-NLSP)
50
60
70
80
90
100
-12 -10 -8 -6log(τlife/s)
m(e∼
R) (
GeV
/c2 )
50
60
70
80
90
100
-12 -10 -8 -6
c) e∼
R (l∼
R co-NLSP)
Excluded at 95% C.L.
Median expected limitMedian exp. ±1σMedian exp. ±2σ
Figure 19: The observed lower mass limits for pair-produced staus in the stau NLSP (a) andsmuons (b), selectrons (c) in the slepton co-NLSP scenario as a function of the particle lifetimeusing the direct ℓ+ℓ− search. For staus in the slepton co-NLSP scenario the observed and expectedlower limit are identical to the limits of the stau in the stau NLSP scenario. The mass limits arevalid for a messenger index N≤ 5. For the stau NLSP and slepton co-NLSP scenarios, the NLSPmass limits are set by the stau mass limit (mNLSP > 87.4GeV/c2 (a)) and by the smuon mass limit(mNLSP > 93.7GeV/c2 (b)), respectively.
61
mτ > 87 GeV mµ > 94 GeV
OPAL placed the best limits on sleptons of all lifetimes
Evans (UIUC) Displaced Leptons February 16, 2016 12 / 39
Relevant LHC search: HSCP
At long lifetime: cττ & 1m⇒ heavy, detector-stable, charged particle
CMS HSCP search 1305.0491 (expect similar from ATLAS 1411.6795)
Cuts
Central: |η| < 2.4
Hard: pT > 70 GeV
Isolated:∑
ptrksT ,∆R<0.3 < 50 GeV
Icalo,track∆R<0.3 < 0.3
Slow: 1/β > 1.225
Large dE/dx : see 1305.0491
Efficiency maps provided: 1502.02522200 400 600 800
100
200
500
1000
2000
5000
mWé HGeVL
ctHcmL
CMS HSCP ExclusionOur Recast H±25%L
Evans (UIUC) Displaced Leptons February 16, 2016 13 / 39
Relevant LHC search: Disappearing TracksCMS 1411.6006
At slightly shorter lifetimes: 30 cm . cττ . 3 m⇒ disappearing tracks
Cuts
A hard jet: pT > 110 GeV, |η| < 2.4
Missing energy: E/T > 100 GeV
Hard track stub: pT > 50 GeVFew outer tracker hits
Particular eta: 1.85 < |η| < 2.10.35 < |η| < 1.42or |η| < 0.15
Isolated: Ecalo∆R<0.5 < 10 GeV
I trks,track∆R<0.3 < 0.05
Simple efficiency map provided 1411.6006
100 200 300 400 500 600
5
10
50
100
500
mW HGeVL
cΤHcm
LCMS DT Exclusion
Our Recast H±50%L
Evans (UIUC) Displaced Leptons February 16, 2016 14 / 39
Relevant LHC search: Disappearing TracksATLAS 1310.3675
At slightly shorter lifetimes: 20 cm . cττ . 2 m⇒ disappearing tracks
Cuts
A hard jet: pT > 90 GeV, |η| < 2.5
Missing energy: E/T > 90 GeV
Hard track stub: pT > 75 GeVhighest pT track in event< 5 hits in TRT
Eta: 0.1 < |η| < 1.9
Isolated: I trks,track∆R<0.4 < 0.04
∆Rjt >0.4∀pT ,j>45 GeV
Veto leptons: es, µs, &µ calo tracks > 10 GeV
No efficiency map provided
100 200 300 400 500 600
5
10
50
100
500
mW HGeVL
cΤHcm
LATLAS Exclusion
Our Recast H±50%L
Evans (UIUC) Displaced Leptons February 16, 2016 15 / 39
Relevant LHC search: Disappearing TracksRecast Caveats
Isolation requirements are hard on long-lived staus
Even with wide opening angles,effective ∆R can be very small
(We model this, but very uncertain)
Evans (UIUC) Displaced Leptons February 16, 2016 16 / 39
Relevant LHC search: CMS Displaced eµ (1409.4789)Cuts
Cut Summary of CMS eµPreselection
1 OS e±µ∓ paird` > 100µm
pT ,` > 25 GeV, |η`| < 2.5Reject 1.44 < |ηe| < 1.56
Icalo,e∆R<0.3 < 0.10, Icalo,µ
∆R<0.4 < 0.12∆R`j > 0.5 ∀ jets with pT > 10 GeV
∆Reµ > 0.5vT , ˜ < 4 cm, vZ , ˜ < 30 cm
Veto additional leptons0.10.050.02 21
0.1
0.05
1
0.02
2
dm
de SR3
SR2
SR1
.............................................. ..........................
.............................................. ..........................
.............................................. ..........................
.............................................. ..........................
Extensive recasting details provided!
Evans (UIUC) Displaced Leptons February 16, 2016 17 / 39
Relevant LHC search: CMS Displaced eµ (1409.4789)Cuts
Cut Summary of CMS eµPreselection
1 OS e±µ∓ paird` > 100µm
pT ,` > 25 GeV, |η`| < 2.5Reject 1.44 < |ηe| < 1.56
Icalo,e∆R<0.3 < 0.10, Icalo,µ
∆R<0.4 < 0.12∆R`j > 0.5 ∀ jets with pT > 10 GeV
∆Reµ > 0.5vT , ˜ < 4 cm, vZ , ˜ < 30 cm
Veto additional leptons0.10.050.02 21
0.1
0.05
1
0.02
2
dm
de SR3
SR2
SR1
.............................................. ..........................
.............................................. ..........................
.............................................. ..........................
.............................................. ..........................
Extensive recasting details provided!
Evans (UIUC) Displaced Leptons February 16, 2016 17 / 39
Relevant LHC search: CMS Displaced eµ (1409.4789)Cuts
Cut Summary of CMS eµPreselection
1 OS e±µ∓ paird` > 100µm
pT ,` > 25 GeV, |η`| < 2.5Reject 1.44 < |ηe| < 1.56
Icalo,e∆R<0.3 < 0.10, Icalo,µ
∆R<0.4 < 0.12∆R`j > 0.5 ∀ jets with pT > 10 GeV
∆Reµ > 0.5vT , ˜ < 4 cm, vZ , ˜ < 30 cm
Veto additional leptons0.10.050.02 21
0.1
0.05
1
0.02
2
dm
de SR3
SR2
SR1
.............................................. ........................................................................ ..........................
.............................................. ..........................
.............................................. ..........................
Extensive recasting details provided!
Evans (UIUC) Displaced Leptons February 16, 2016 17 / 39
Relevant LHC search: CMS Displaced eµ (1409.4789)Cuts
Cut Summary of CMS eµPreselection
1 OS e±µ∓ paird` > 100µm
pT ,` > 25 GeV, |η`| < 2.5Reject 1.44 < |ηe| < 1.56
Icalo,e∆R<0.3 < 0.10, Icalo,µ
∆R<0.4 < 0.12∆R`j > 0.5 ∀ jets with pT > 10 GeV
∆Reµ > 0.5vT , ˜ < 4 cm, vZ , ˜ < 30 cm
Veto additional leptons0.10.050.02 21
0.1
0.05
1
0.02
2
dm
de SR3
SR2
SR1
.............................................. ........................................................................ ..........................
.............................................. ..........................
.............................................. ..........................
Extensive recasting details provided!
Evans (UIUC) Displaced Leptons February 16, 2016 17 / 39
Relevant LHC search: CMS Displaced eµ (1409.4789)Recast
Cut Summary of CMS eµPreselection
1 OS e±µ∓ paird` > 100µm
pT ,` > 25 GeV, |η`| < 2.5Reject 1.44 < |ηe| < 1.56
Icalo,e∆R<0.3 < 0.10, Icalo,µ
∆R<0.4 < 0.12∆R`j > 0.5 ∀ jets with pT > 10 GeV
∆Reµ > 0.5vT , ˜ < 4 cm, vZ , ˜ < 30 cm
Veto additional leptons400 500 600 700 800 900
0.1
1
10
100
mté HGeVLctHcmL
CMS em ExclusionOur Recast H±25%L
.............................................. ........................................................................ ..........................
.............................................. ..........................
.............................................. ..........................
Extensive recasting details provided!
Evans (UIUC) Displaced Leptons February 16, 2016 17 / 39
Relevant LHC search: CMS Displaced eµ (1409.4789)Impact Parameter
µ→ µG τ → µνν
dy
dx
Impact Parameter is not the location of parent
b and τ decay products are more collimated
Evans (UIUC) Displaced Leptons February 16, 2016 18 / 39
Relevant LHC search: CMS Displaced eµ (1409.4789)Backgrounds & Data4
[cm]0Electron d0 0.1 0.2 0.3 0.4 0.5
Entri
es /
0.01
cm
-310
-210
-110
1
10
210
310DataStat. & syst. errors
ττ→ZHFOther EWTop quark
= 0.1 cm)τ (ct~t~ = 1 cm)τ (ct~t~ = 10 cm)τ (ct~t~ = 0.1 cm)τ (ct~t~ = 1 cm)τ (ct~t~ = 10 cm)τ (ct~t~
CMS (8 TeV)-119.7 fb
[cm]0Muon d0 0.1 0.2 0.3 0.4 0.5
Entri
es /
0.01
cm
-310
-210
-110
1
10
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310DataStat. & syst. errors
ττ→ZHFOther EWTop quark
= 0.1 cm)τ (ct~t~ = 1 cm)τ (ct~t~ = 10 cm)τ (ct~t~ = 0.1 cm)τ (ct~t~ = 1 cm)τ (ct~t~ = 10 cm)τ (ct~t~
CMS (8 TeV)-119.7 fb
Figure 1: Lepton transverse impact parameter distributions for data and expected backgroundprocesses after the preselection requirements have been applied, for electrons (left) and muons(right). The signal expected from 500 GeV top squark pair production is overlaid for ct =0.1 cm, 1 cm, and 10 cm. The event yields per bin have been rescaled to account for the varyingbin sizes. The rightmost bin of each plot contains the overflow entries.
less exclusive neighboring search region, which should always overestimate the backgroundin that bin. This technique produces virtually identical limits to simply using a null estimate inthese cases.
There are several sources of systematic uncertainty in this search. Cross section uncertaintiesfor simulated data sets range from 4% to 8% for the SM background and 15% to 28% for thesignal process. Following the official PDF4LHC recommendation [47], we obtain PDF uncer-tainties using an envelope of several PDF sets, ranging from 1% to 5%. The PDF and crosssection uncertainties are propagated into the limits for all simulated data sets. The luminos-ity estimate, based on the pixel cluster counting method [48], has an uncertainty of 2.6%. Forthe displaced track reconstruction efficiency, the (4%) correction is correlated for each lepton,resulting in a 8.0% systematic uncertainty per event. The uncertainty in the data-driven HF es-timate is 30% and is dominated by the limited size of the sample used. Uncertainties in triggerefficiency, pileup correction, and lepton correction factors are calculated and incorporated butare small compared to the previously mentioned uncertainties.
Table 1 shows the numbers of observed and expected background events in the three searchregions. We do not observe any significant excess over the background expectation. We set95% confidence level (CL) upper limits on the cross section for top squark pair production at8 TeV. We perform this as a simultaneous counting experiment in three bins of the three searchregions. We use a Bayesian calculation assuming a flat prior for the signal as a function oftop squark mass. Nuisance parameters arising from statistical uncertainties are modeled asgamma distributions, while all others are modeled as log-normal distributions. These crosssection limits are translated into upper limits on the top squark mass, where the cross sectionfor each mass hypothesis is calculated at next-to-leading-order and next-to-leading-logarithmicprecision within a simplified model with decoupled squarks and gluinos [49–51]. The resultingexpected and observed limit contours are shown in Fig. 2. The region to the left of the contoursis excluded. For a lifetime of ct = 2 cm, we exclude top squark masses up to 790 GeV, to becompared with a value of 780 GeV expected in the absence of any signal.
5
Table 1: Numbers of expected and observed events in the three search regions (see thetext for the definitions of these regions). Background and signal expectations are quoted asNexp ± 1s (stat)± 1s (syst). If the estimated background is zero in a particular search region,the estimate is instead taken from the preceding region. Since this should always overestimatethe background, we denote this by a preceding “<”.
Event source SR1 SR2 SR3Other EW 0.65± 0.13± 0.09 (0.89± 0.53± 0.12) 102 <(89± 53± 12) 104
Top quark 0.77± 0.04± 0.08 (1.25± 0.26± 0.12) 102 (2.4± 1.3± 0.2) 104
Z!tt 3.93± 0.42± 0.39 (0.73± 0.73± 0.07) 102 <(73± 73± 7) 104
HF 12.7± 0.2± 3.8 (98± 6± 30) 102 (340± 110± 100) 104
Total expected background 18.0± 0.5± 3.8 1.01± 0.06± 0.30 0.051± 0.015± 0.010Observed 19 0 0
pp!etet (Met = 500 GeV)ct = 0.1 cm 30.1± 0.7± 5.3 6.54± 0.34± 1.16 1.34± 0.15± 0.24ct = 1 cm 35.3± 0.8± 6.2 30.3± 0.7± 5.3 51.3± 1.0± 9.0ct = 10 cm 4.73± 0.30± 0.83 5.57± 0.32± 0.98 26.3± 0.7± 4.6
In summary, a search has been performed for new physics with an electron and muon with op-posite charges having a signature of large impact parameter values, with no requirements madeon jets or missing transverse energy. No excess is observed above background for displace-ments up to 2 cm. While this search is expected to have sensitivity to a wide range of theoret-ical models, the results are interpreted in the context of a displaced supersymmetry model [1]with a pair-produced top squark having a lifetime between ct = 0.02 cm and ct = 100 cm.Limits are placed at 95% C.L. on this model as a function of top squark mass and lifetime. Fora lifetime hypothesis of ct = 2 cm, top squark masses up to 790 GeV are excluded. These arethe most restrictive limits obtained to date on this model.
AcknowledgmentsWe congratulate our colleagues in the CERN accelerator departments for the excellent perfor-mance of the LHC and thank the technical and administrative staffs at CERN and at other CMSinstitutes for their contributions to the success of the CMS effort. In addition, we gratefullyacknowledge the computing centers and personnel of the Worldwide LHC Computing Gridfor delivering so effectively the computing infrastructure essential to our analyses. Finally, weacknowledge the enduring support for the construction and operation of the LHC and the CMSdetector provided by the following funding agencies: BMWFW and FWF (Austria); FNRS andFWO (Belgium); CNPq, CAPES, FAPERJ, and FAPESP (Brazil); MES (Bulgaria); CERN; CAS,MoST, and NSFC (China); COLCIENCIAS (Colombia); MSES and CSF (Croatia); RPF (Cyprus);MoER, ERC IUT and ERDF (Estonia); Academy of Finland, MEC, and HIP (Finland); CEA andCNRS/IN2P3 (France); BMBF, DFG, and HGF (Germany); GSRT (Greece); OTKA and NIH(Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); NRF and WCU (Re-public of Korea); LAS (Lithuania); MOE and UM (Malaysia); CINVESTAV, CONACYT, SEP,and UASLP-FAI (Mexico); MBIE (New Zealand); PAEC (Pakistan); MSHE and NSC (Poland);FCT (Portugal); JINR (Dubna); MON, RosAtom, RAS and RFBR (Russia); MESTD (Serbia);SEIDI and CPAN (Spain); Swiss Funding Agencies (Switzerland); MST (Taipei); ThEPCenter,IPST, STAR and NSTDA (Thailand); TUBITAK and TAEK (Turkey); NASU and SFFR (Ukraine);STFC (United Kingdom); DOE and NSF (U.S.).
Evans (UIUC) Displaced Leptons February 16, 2016 19 / 39
Recast Limits on τR
Only HSCP limits on direct τR production!
But . . . a τR is not expected in isolation
Near degenerate slepton limits
meR= mµR = mτR + 10 GeV
˜R → τR + soft
100 125 150 175 200 225 2500.1
1
10
100
1000
5
50
500
0.5
mté HGeVL
ctHcmL
OPAL Limit
té only téRêméRêeéRHSCPDTem
(Better limit from both disappearing track searches shown)
Limits are very sensitive to mτR
Evans (UIUC) Displaced Leptons February 16, 2016 20 / 39
Recast Limits on τR
Only HSCP limits on direct τR production!
But . . . a τR is not expected in isolation
Near degenerate slepton limits
meR= mµR = mτR + 10 GeV
˜R → τR + soft
100 125 150 175 200 225 2500.1
1
10
100
1000
5
50
500
0.5
mté HGeVLctHcmL
OPAL Limit
té only téRêméRêeéRHSCPDTem
(Better limit from both disappearing track searches shown)
Limits are very sensitive to mτR
Evans (UIUC) Displaced Leptons February 16, 2016 20 / 39
Recast Limits on τR
Only HSCP limits on direct τR production!
But . . . a τR is not expected in isolation
Higgsino production limits
mχ01
= mχ02
= mχ+1
χ01,2 → τ±R τ
∓, χ±1 → τ±R ν
150 200 250 300 350 400 450 500 550
0.1
1
10
100
1000
5
50
500
0.05
0.5
mHé HGeVL
ctHcmL
mté=100 300HSCPDTem
(Better limit from both disappearing track searches shown)
Limits are very sensitive to mτR
Evans (UIUC) Displaced Leptons February 16, 2016 20 / 39
Recast Limits on τR
Only HSCP limits on direct τR production!
But . . . a τR is not expected in isolation
Stop production limits
mH = mt − 50 GeV
t → bH+ → bντ+R
200 300 400 500 600 700 800 900
0.1
1
10
100
1000
5
50
500
0.05
0.5
mté HGeVLctHcmL
mté=100 300 500HSCPDTem
(Better limit from both disappearing track searches shown)
Limits are very sensitive to mτR
Evans (UIUC) Displaced Leptons February 16, 2016 20 / 39
Recast Limits on τR
Only HSCP limits on direct τR production!
But . . . a τR is not expected in isolation
Gluino production limits
mt = mg − 200 GeVmH = mt − 50 GeV
g → t t → tbH+ → tbντ+R
g → t∗t → t bH− → t bντ−R400 500 600 700 800 900 10001100120013001400
0.1
1
10
100
1000
5
50
500
0.05
0.5
mgé HGeVLctHcmL
mté=100 300 500HSCPDTem
(Better limit from both disappearing track searches shown)
Limits are very sensitive to mτR
Evans (UIUC) Displaced Leptons February 16, 2016 20 / 39
Potential Improvements?HSCP
CMS heavy, stable, charged particle search does very well!
Using “tracker-only” signal region could improve sensitivity
Currently no efficiency maps provided
100 125 150 175 200 225 2500.1
1
10
100
1000
5
50
500
0.5
mté HGeVL
ctHcmL
OPAL Limit
té only téRêméRêeéRHSCPDTem
q qqqqqqqqq qqqqqqqq qqqqqqq qqqqqq qqqqq qqqqq qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq qqqqq qqqqq qqqqqq qqqqqqq qqqqqqqq qqqqqqqqq
Evans (UIUC) Displaced Leptons February 16, 2016 21 / 39
Potential Improvements?Disappearing Tracks
ATLAS hurt by lepton vetoes and hardest track requirement
100 150 200 250 300 350 400 450 5001
10
100
1000
5
50
500
mté or mHé HGeVL
ctHcmL
mté=100 300téRêméRêeéRHé
ATLAS DTCMS DT
200 300 400 500 600 700 8001
10
100
1000
5
50
500
mté HGeVL
ctHcmL
mté=100 300 500
ATLAS DTCMS DT
Both disappearing tracks searches are hurt by isolation requirements
Could similar pre-selection capitalize on kinked track?
Evans (UIUC) Displaced Leptons February 16, 2016 22 / 39
Potential Improvements?CMS Displaced Lepton Search
There are several lessons from GMSB τRs to improve sensitivity
BR(τ+τ− → e±µ∓ + X ) = 6%BR(τ+τ− → e+e− + X ) = 3%BR(τ+τ− → µ+µ− + X ) = 3%
1) Add same-flavor lepton channels
BR(τ+τ− → e±τ∓h + X ) = 23%BRτ+τ− → µ±τ∓h + X ) = 23%BR(τ+τ− → τ±h τ
∓h + X ) = 42%
2) Include hadronic τhs
Experimental feasibility of displaced τhs?
Evans (UIUC) Displaced Leptons February 16, 2016 23 / 39
Potential Improvements?CMS Displaced Lepton Search
There are several lessons from GMSB τRs to improve sensitivity
BR(τ+τ− → e±µ∓ + X ) = 6%BR(τ+τ− → e+e− + X ) = 3%BR(τ+τ− → µ+µ− + X ) = 3%
1) Add same-flavor lepton channels
BR(τ+τ− → e±τ∓h + X ) = 23%BRτ+τ− → µ±τ∓h + X ) = 23%BR(τ+τ− → τ±h τ
∓h + X ) = 42%
2) Include hadronic τhs
Experimental feasibility of displaced τhs?
Evans (UIUC) Displaced Leptons February 16, 2016 23 / 39
Potential Improvements?CMS Displaced Lepton Search
0.0 0.1 0.2 0.3 0.4 0.50
1
2
3
4
ΤR ΤL
1Γ
dΓdx
x = E`/mτ
Right-handed polarized τs from τR decays give softer leptons
3) Lower pT thresholds can capture a lot more signalAdditional triggers – E/T + ``, E/T , ```, etc
Evans (UIUC) Displaced Leptons February 16, 2016 24 / 39
Potential Improvements?CMS Displaced Lepton Search
Search vetoes additional leptons.Why?
Displaced multilepton backgroundshould be very small
(CDF ghost muons???)
d (cm)0 0.5 1 1.5 2
Muo
ns /
(0.0
08 c
m)
1
10
210
310
410
510
610
FIG. 7: Impact parameter distribution of muons contributed by ghost (•) and QCD (histogram)
events. Muon tracks are selected with loose SVX requirements. The detector resolution is ≃ 30 µm,
whereas bins are 80 µm wide.
1/ptrackT )2/σ2
1/pT] to measure the difference between the momentum vectors of the undecayed
pions or kaons (h) and that of the closest reconstructed tracks 3. Figure 9 shows the ∆
distribution as a function of R, the decay distance from the beamline. One notes that most
of the decays at radial distances R ≤ 120 cm yield misreconstructed tracks. The numbers
3 The assumed experimental resolutions are σφ[rad] = ση = 10−3 and σ1/pT= 2 · 10−3 [GeV/c]−1.
20
CDF 0810.5357
Gluino & Higgsino model have additional leptons often ∼(45%, 30%)
If pair-produced object is not charged under lepton number,additional leptons are generic
4) Don’t veto additional leptons
Evans (UIUC) Displaced Leptons February 16, 2016 25 / 39
Potential Improvements?CMS Displaced Lepton Search
Search vetoes additional leptons.Why?
Displaced multilepton backgroundshould be very small
(CDF ghost muons???)
d (cm)0 0.5 1 1.5 2
Muo
ns /
(0.0
08 c
m)
1
10
210
310
410
510
610
FIG. 7: Impact parameter distribution of muons contributed by ghost (•) and QCD (histogram)
events. Muon tracks are selected with loose SVX requirements. The detector resolution is ≃ 30 µm,
whereas bins are 80 µm wide.
1/ptrackT )2/σ2
1/pT] to measure the difference between the momentum vectors of the undecayed
pions or kaons (h) and that of the closest reconstructed tracks 3. Figure 9 shows the ∆
distribution as a function of R, the decay distance from the beamline. One notes that most
of the decays at radial distances R ≤ 120 cm yield misreconstructed tracks. The numbers
3 The assumed experimental resolutions are σφ[rad] = ση = 10−3 and σ1/pT= 2 · 10−3 [GeV/c]−1.
20
CDF 0810.5357
Gluino & Higgsino model have additional leptons often ∼(45%, 30%)
If pair-produced object is not charged under lepton number,additional leptons are generic
4) Don’t veto additional leptons
Evans (UIUC) Displaced Leptons February 16, 2016 25 / 39
Potential Improvements?CMS Displaced Lepton Search
Search vetoes additional leptons.Why?
Displaced multilepton backgroundshould be very small
(CDF ghost muons???)
d (cm)0 0.5 1 1.5 2
Muo
ns /
(0.0
08 c
m)
1
10
210
310
410
510
610
FIG. 7: Impact parameter distribution of muons contributed by ghost (•) and QCD (histogram)
events. Muon tracks are selected with loose SVX requirements. The detector resolution is ≃ 30 µm,
whereas bins are 80 µm wide.
1/ptrackT )2/σ2
1/pT] to measure the difference between the momentum vectors of the undecayed
pions or kaons (h) and that of the closest reconstructed tracks 3. Figure 9 shows the ∆
distribution as a function of R, the decay distance from the beamline. One notes that most
of the decays at radial distances R ≤ 120 cm yield misreconstructed tracks. The numbers
3 The assumed experimental resolutions are σφ[rad] = ση = 10−3 and σ1/pT= 2 · 10−3 [GeV/c]−1.
20
CDF 0810.5357
Gluino & Higgsino model have additional leptons often ∼(45%, 30%)
If pair-produced object is not charged under lepton number,additional leptons are generic
4) Don’t veto additional leptons
Evans (UIUC) Displaced Leptons February 16, 2016 25 / 39
Potential Improvements?CMS Displaced Lepton Search
Gluino & Higgsino models have Majorana particles in chain
⇒ same-sign displaced leptons
5) Include same-sign displaced lepton signal regions
5’) Same-sign possibility fairly generic, be wary of CR contamination
SS` can appear in the t → `+b benchmark of CMS 1409.4789Mesino oscillation allows up to 3/8 of events as SS` Sarid, Thomas – 9909349
Evans (UIUC) Displaced Leptons February 16, 2016 26 / 39
Potential Improvements?CMS Displaced Lepton Search
Gluino & Higgsino models have Majorana particles in chain
⇒ same-sign displaced leptons
5) Include same-sign displaced lepton signal regions
5’) Same-sign possibility fairly generic, be wary of CR contamination
SS` can appear in the t → `+b benchmark of CMS 1409.4789Mesino oscillation allows up to 3/8 of events as SS` Sarid, Thomas – 9909349
Evans (UIUC) Displaced Leptons February 16, 2016 26 / 39
Potential Improvements?CMS Displaced Lepton Search
150 200 250 300 350 400 450 500 550
0.1
1
10
100
1000
5
50
500
0.05
0.5
mHé HGeVL
ctHcmL
mté=100 300HSCPDTem
q qqqqqqqqqq qqqqqqqqq qqqqqqqq qqqqqqq qqqqqq qqqqq qqqq qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq qqqq qqqqq qqqqqq qqqqqqq qqqqqqqq qqqqqqqqq qqqqqqqqqq
............................................................................................................... ....
..............
.........
............
...............
.................
..........................Prompt
Extend reach in cτ?
6) Allow d0 above 2 cm(Even just for muons)
7) Relax isolation in high d0 bins(Backgrounds are small there)
Evans (UIUC) Displaced Leptons February 16, 2016 27 / 39
Potential Improvements?CMS Displaced Lepton Search
150 200 250 300 350 400 450 500 550
0.1
1
10
100
1000
5
50
500
0.05
0.5
mHé HGeVL
ctHcmL
mté=100 300HSCPDTem
q qqqqqqqqqq qqqqqqqqq qqqqqqqq qqqqqqq qqqqqq qqqqq qqqq qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq qqqq qqqqq qqqqqq qqqqqqq qqqqqqqq qqqqqqqqq qqqqqqqqqq
............................................................................................................... ....
..............
.........
............
...............
.................
..........................Prompt
Extend reach in cτ?
6) Allow d0 above 2 cm(Even just for muons)
7) Relax isolation in high d0 bins(Backgrounds are small there)
Evans (UIUC) Displaced Leptons February 16, 2016 27 / 39
Potential Improvements?CMS Displaced Lepton Search
150 200 250 300 350 400 450 500 550
0.1
1
10
100
1000
5
50
500
0.05
0.5
mHé HGeVL
ctHcmL
mté=100 300HSCPDTem
q qqqqqqqqqq qqqqqqqqq qqqqqqqq qqqqqqq qqqqqq qqqqq qqqq qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq qqqq qqqqq qqqqqq qqqqqqq qqqqqqqq qqqqqqqqq qqqqqqqqqq
............................................................................................................... ....
..............
.........
............
...............
.................
..........................Prompt
Extend reach in cτ?
6) Allow d0 above 2 cm(Even just for muons)
7) Relax isolation in high d0 bins(Backgrounds are small there)
Evans (UIUC) Displaced Leptons February 16, 2016 27 / 39
Same-flavor Displaced Lepton ModelsSlepton Co-NLSP in GGM
If m˜R−mτR 10 GeV or mB mτR ,
then Γ(˜R → `τ τR) Γ(˜R → `G) ⇒ Slepton Co-NLSP
Events have displaced e+e−, µ+µ−, or τ+τ−
Small splitting can happen for low tanβ
In GGM, M1 and m2ER
are independent
µ+µ− and e+e− searches would be more sensitive to this model
Can one get 100% e+e− or µ+µ− without τ+τ−?
Evans (UIUC) Displaced Leptons February 16, 2016 28 / 39
Same-flavor Displaced Lepton ModelsSlepton Co-NLSP in GGM
If m˜R−mτR 10 GeV or mB mτR ,
then Γ(˜R → `τ τR) Γ(˜R → `G) ⇒ Slepton Co-NLSP
Events have displaced e+e−, µ+µ−, or τ+τ−
Small splitting can happen for low tanβ
In GGM, M1 and m2ER
are independent
µ+µ− and e+e− searches would be more sensitive to this model
Can one get 100% e+e− or µ+µ− without τ+τ−?
Evans (UIUC) Displaced Leptons February 16, 2016 28 / 39
Same-flavor Displaced Lepton ModelsSlepton Co-NLSP in GGM
If m˜R−mτR 10 GeV or mB mτR ,
then Γ(˜R → `τ τR) Γ(˜R → `G) ⇒ Slepton Co-NLSP
Events have displaced e+e−, µ+µ−, or τ+τ−
Small splitting can happen for low tanβ
In GGM, M1 and m2ER
are independent
µ+µ− and e+e− searches would be more sensitive to this model
Can one get 100% e+e− or µ+µ− without τ+τ−?
Evans (UIUC) Displaced Leptons February 16, 2016 28 / 39
Same-flavor Displaced Lepton Modelsτ1 with LLE RPV
RPV can do almost anything
•@@
superpartner
SM
SM
W = 12λijk Li Lj Ec
k + λ′ijk Li Qj Dck + 1
2λ′′ijk Uc
i Dcj Dc
k + µi Li Hu
i, j, k = generation indices
•LLE
@@
˜L,i
`k
νj
•@@
˜R,k
`i,j
νj,i
•@@
νi
`j
`kq qqqqqqqqqq qqqqqqqqq qqqqqqqq qqqqqqqq qqqqqqq qqqqqq qqqqqq qqqqqq qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq qqqqqq qqqqqq
qqqqqq qqqqqqq qqqqqqqq qqqqqqqq qqqqqqqqq qqqqqqqqqq
cτ ≈ 1 cm(
10−7
λ232
)2(100 GeVmτ
)sec2 θτ (θτ = 0⇒ τ1 = τL)
λ232 cos θτ other RPV ⇒ BR(τ1 → µν) ≈ 100%
Evans (UIUC) Displaced Leptons February 16, 2016 29 / 39
Same-flavor Displaced Lepton Modelsτ1 with LLE RPV
RPV can do almost anything
•@@
superpartner
SM
SM
W = 12λijk Li Lj Ec
k + λ′ijk Li Qj Dck + 1
2λ′′ijk Uc
i Dcj Dc
k + µi Li Hu
i, j, k = generation indices
•LLE
@@
˜L,i
`k
νj
•@@
˜R,k
`i,j
νj,i
•@@
νi
`j
`k
q qqqqqqqqqq qqqqqqqqq qqqqqqqq qqqqqqqq qqqqqqq qqqqqq qqqqqq qqqqqq qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq qqqqqq qqqqqq
qqqqqq qqqqqqq qqqqqqqq qqqqqqqq qqqqqqqqq qqqqqqqqqq
cτ ≈ 1 cm(
10−7
λ232
)2(100 GeVmτ
)sec2 θτ (θτ = 0⇒ τ1 = τL)
λ232 cos θτ other RPV ⇒ BR(τ1 → µν) ≈ 100%
Evans (UIUC) Displaced Leptons February 16, 2016 29 / 39
Same-flavor Displaced Lepton Modelsτ1 with LLE RPV
RPV can do almost anything
•@@
superpartner
SM
SM
W = 12λijk Li Lj Ec
k + λ′ijk Li Qj Dck + 1
2λ′′ijk Uc
i Dcj Dc
k + µi Li Hu
i, j, k = generation indices
•LLE
@@
˜L,i
`k
νj
•@@
˜R,k
`i,j
νj,i
•@@
νi
`j
`kq qqqqqqqqqq qqqqqqqqq qqqqqqqq qqqqqqqq qqqqqqq qqqqqq qqqqqq qqqqqq qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq qqqqqq qqqqqq
qqqqqq qqqqqqq qqqqqqqq qqqqqqqq qqqqqqqqq qqqqqqqqqq
cτ ≈ 1 cm(
10−7
λ232
)2(100 GeVmτ
)sec2 θτ (θτ = 0⇒ τ1 = τL)
λ232 cos θτ other RPV ⇒ BR(τ1 → µν) ≈ 100%
Evans (UIUC) Displaced Leptons February 16, 2016 29 / 39
Same-flavor Displaced Lepton ModelsEGMSB
Extended GMSB (EGMSB) models can generate large At
for maximal t mixing and decreased tuning of the MSSM HiggsCraig, Knapen, Shih, Zhao – 1206.4086; Evans, Shih – 1303.0228; others
EGMSB can also give a 1st- or 2nd-gen slepton NLSP Shadmi, Szabo – 1103.0292
Add EGMSB MSSM-Messenger coupling: W ⊃ κiEci ΦUΦD
~κ = (0, κ2,0) gives ∆mµ ∼ −25κ22m˜
κ2 ∼ 0.1⇒ µR NLSP
κ1κ2 0.1 & κ3
κ2. 0.3 no CMS eµ sensitivity and safe from flavor
Evans (UIUC) Displaced Leptons February 16, 2016 30 / 39
Same-flavor Displaced Lepton ModelsEGMSB
Extended GMSB (EGMSB) models can generate large At
for maximal t mixing and decreased tuning of the MSSM HiggsCraig, Knapen, Shih, Zhao – 1206.4086; Evans, Shih – 1303.0228; others
EGMSB can also give a 1st- or 2nd-gen slepton NLSP Shadmi, Szabo – 1103.0292
Add EGMSB MSSM-Messenger coupling: W ⊃ κiEci ΦUΦD
~κ = (0, κ2,0) gives ∆mµ ∼ −25κ22m˜
κ2 ∼ 0.1⇒ µR NLSP
κ1κ2 0.1 & κ3
κ2. 0.3 no CMS eµ sensitivity and safe from flavor
Evans (UIUC) Displaced Leptons February 16, 2016 30 / 39
Same-flavor Displaced Lepton ModelsFreezein of Dark Matter During a Matter-Dominated Era
Minimal models of lepton-flavored DM
Model Mediator DM Lagrangian1 Scalar Fermion yLDM
ij `ci ζ−χi + m2
ζζ+ζ− + mχ,ijχi χj
2 Fermion Scalar yLDMij `ci ψSj + mψψψ + m2
S,ijS†i Sj
yLDM for cτ ∼ O (1mm − 1m)⇒ ΩDM too high!
Inflaton decay⇓
early matter-dominated era
TRH < mψ/ζ ⇒ less ΩDMdue to entropy injection
Co, D’Eramo, Hall, Pappadopulo - 1506.07532
Evans (UIUC) Displaced Leptons February 16, 2016 31 / 39
Same-flavor Displaced Lepton ModelsFreezein of Dark Matter During a Matter-Dominated Era
Minimal models of lepton-flavored DM
Model Mediator DM Lagrangian1 Scalar Fermion yLDM
ij `ci ζ−χi + m2
ζζ+ζ− + mχ,ijχi χj
2 Fermion Scalar yLDMij `ci ψSj + mψψψ + m2
S,ijS†i Sj
yLDM for cτ ∼ O (1mm − 1m)⇒ ΩDM too high!
Inflaton decay⇓
early matter-dominated era
TRH < mψ/ζ ⇒ less ΩDMdue to entropy injection
Co, D’Eramo, Hall, Pappadopulo - 1506.07532
Evans (UIUC) Displaced Leptons February 16, 2016 31 / 39
Same-flavor Displaced Lepton ModelsFreezein of Dark Matter During a Matter-Dominated Era
Minimal models of lepton-flavored DM
Model Mediator DM Lagrangian1 Scalar Fermion yLDM
ij `ci ζ−χi + m2
ζζ+ζ− + mχ,ijχi χj
2 Fermion Scalar yLDMij `ci ψSj + mψψψ + m2
S,ijS†i Sj
yLDM for cτ ∼ O (1mm − 1m)⇒ ΩDM too high!
For Model 2:
ΩDM
ΩDM,obs≈(
20mψ/TRH
)7(500 GeVmψ
)2 ( mS
1 MeV
)(1 cmcτψ
)
For 100 GeV < mψ . 1 TeV and 100 µm . cτ . 1 m
mS mψ and TRH can be chosen to give ΩDM = ΩDM,obs!
Evans (UIUC) Displaced Leptons February 16, 2016 31 / 39
Same-Flavor Displaced Lepton SearchBackgrounds
How can we estimate 13 TeV backgrounds?4
[cm]0Electron d0 0.1 0.2 0.3 0.4 0.5
Entri
es /
0.01
cm
-310
-210
-110
1
10
210
310DataStat. & syst. errors
ττ→ZHFOther EWTop quark
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CMS (8 TeV)-119.7 fb
Figure 1: Lepton transverse impact parameter distributions for data and expected backgroundprocesses after the preselection requirements have been applied, for electrons (left) and muons(right). The signal expected from 500 GeV top squark pair production is overlaid for ct =0.1 cm, 1 cm, and 10 cm. The event yields per bin have been rescaled to account for the varyingbin sizes. The rightmost bin of each plot contains the overflow entries.
less exclusive neighboring search region, which should always overestimate the backgroundin that bin. This technique produces virtually identical limits to simply using a null estimate inthese cases.
There are several sources of systematic uncertainty in this search. Cross section uncertaintiesfor simulated data sets range from 4% to 8% for the SM background and 15% to 28% for thesignal process. Following the official PDF4LHC recommendation [47], we obtain PDF uncer-tainties using an envelope of several PDF sets, ranging from 1% to 5%. The PDF and crosssection uncertainties are propagated into the limits for all simulated data sets. The luminos-ity estimate, based on the pixel cluster counting method [48], has an uncertainty of 2.6%. Forthe displaced track reconstruction efficiency, the (4%) correction is correlated for each lepton,resulting in a 8.0% systematic uncertainty per event. The uncertainty in the data-driven HF es-timate is 30% and is dominated by the limited size of the sample used. Uncertainties in triggerefficiency, pileup correction, and lepton correction factors are calculated and incorporated butare small compared to the previously mentioned uncertainties.
Table 1 shows the numbers of observed and expected background events in the three searchregions. We do not observe any significant excess over the background expectation. We set95% confidence level (CL) upper limits on the cross section for top squark pair production at8 TeV. We perform this as a simultaneous counting experiment in three bins of the three searchregions. We use a Bayesian calculation assuming a flat prior for the signal as a function oftop squark mass. Nuisance parameters arising from statistical uncertainties are modeled asgamma distributions, while all others are modeled as log-normal distributions. These crosssection limits are translated into upper limits on the top squark mass, where the cross sectionfor each mass hypothesis is calculated at next-to-leading-order and next-to-leading-logarithmicprecision within a simplified model with decoupled squarks and gluinos [49–51]. The resultingexpected and observed limit contours are shown in Fig. 2. The region to the left of the contoursis excluded. For a lifetime of ct = 2 cm, we exclude top squark masses up to 790 GeV, to becompared with a value of 780 GeV expected in the absence of any signal.
1. Use 8 TeV backgrounds to estimate 8 TeV SF backgrounds2. Rescale backgrounds by σ(13)
σ(8) (supported by HF MC)3. Assume displaced Z → e+e−/µ+µ− is small or can be controlled4. Artificially low trigger, but have a background we can estimate
Evans (UIUC) Displaced Leptons February 16, 2016 32 / 39
Same-Flavor Displaced Lepton SearchBackgrounds
How can we estimate 13 TeV backgrounds?
Sample SR1 SR2 SR3e±µ∓ 8 TeV (CMS actual) 18.0± 3.8 1.01± 0.31 0.051± 0.018e±µ∓ 8 TeV (estimate) 19.8± 4.1 0.92± 0.28 0.055± 0.024e±µ∓ 13 TeV (20 fb−1) 34.1± 6.5 1.49± 0.44 0.086± 0.038e+e− 13 TeV (20 fb−1) 25.2± 3.6 1.43± 0.33 0.31± 0.06µ+µ− 13 TeV (20 fb−1) 13.0± 3.1 0.50± 0.15 0.012± 0.006
1. Use 8 TeV backgrounds to estimate 8 TeV SF backgrounds2. Rescale backgrounds by σ(13)
σ(8) (supported by HF MC)3. Assume displaced Z → e+e−/µ+µ− is small or can be controlled4. Artificially low trigger, but have a background we can estimate
Evans (UIUC) Displaced Leptons February 16, 2016 32 / 39
Same-Flavor Displaced Lepton Search13 TeV Same-Flavor Search
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Evans (UIUC) Displaced Leptons February 16, 2016 33 / 39
Same-Flavor Displaced Lepton SearchImproving a 13 TeV Same-Flavor Search
e+ → e+G⇒ hard leptonsµ+ → µ+G⇒ hard leptonsτ+ → τ+G⇒ soft leptons
8) SF search can be improved withhigher pT ,`, lower background bins
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q qqqqqqqqq qqqqqqqq qqqqqqq qqqqqq qqqqq qqqqq qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq qqqqq qqqqq qqqqqq qqqqqqq qqqqqqqq qqqqqqqqq
Evans (UIUC) Displaced Leptons February 16, 2016 34 / 39
Comments and PerspectivesRecasting
Efficiency maps and recasting instructions are an essential facetto all searches for exotic objects
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Evans (UIUC) Displaced Leptons February 16, 2016 35 / 39
Comments and PerspectivesRecasting
Clear information about applying the search beyond the benchmark
are valuable for recasting to new scenarios
(Admittedly, tricky to assess in advance)
Evans (UIUC) Displaced Leptons February 16, 2016 36 / 39
Comments and PerspectivesKnown unknowns. . .
What more is wanted from theory?
I What is the status of displaced photons without E/T ?
Is there a gap at ATLAS? Does CMS fill it?
I Quirks
What regions of parameter space (mQ vs ΛIC) are constrained?
What new search strategies could fill the gaps?
I Hidden valleys (high mass and Higgs portal)
What classes of models are constrained by existing searches?
Can model-specific details be distilled to a simplified framework?
Minimal set of searches to cover all observable possibilities?
Evans (UIUC) Displaced Leptons February 16, 2016 37 / 39
Comments and PerspectivesKnown unknowns. . .
What more is wanted from theory?
I What is the status of displaced photons without E/T ?
Is there a gap at ATLAS? Does CMS fill it?
I Quirks
What regions of parameter space (mQ vs ΛIC) are constrained?
What new search strategies could fill the gaps?
I Hidden valleys (high mass and Higgs portal)
What classes of models are constrained by existing searches?
Can model-specific details be distilled to a simplified framework?
Minimal set of searches to cover all observable possibilities?
Evans (UIUC) Displaced Leptons February 16, 2016 37 / 39
Comments and PerspectivesKnown unknowns. . .
What more is wanted from theory?
I What is the status of displaced photons without E/T ?
Is there a gap at ATLAS? Does CMS fill it?
I Quirks
What regions of parameter space (mQ vs ΛIC) are constrained?
What new search strategies could fill the gaps?
I Hidden valleys (high mass and Higgs portal)
What classes of models are constrained by existing searches?
Can model-specific details be distilled to a simplified framework?
Minimal set of searches to cover all observable possibilities?
Evans (UIUC) Displaced Leptons February 16, 2016 37 / 39
Comments and PerspectivesKnown unknowns. . .
What more is wanted from theory?
I What is the status of displaced photons without E/T ?
Is there a gap at ATLAS? Does CMS fill it?
I Quirks
What regions of parameter space (mQ vs ΛIC) are constrained?
What new search strategies could fill the gaps?
I Hidden valleys (high mass and Higgs portal)
What classes of models are constrained by existing searches?
Can model-specific details be distilled to a simplified framework?
Minimal set of searches to cover all observable possibilities?
Evans (UIUC) Displaced Leptons February 16, 2016 37 / 39
Comments and PerspectivesKnown unknowns. . .
What more is wanted from experiment?
I Displaced same-flavor leptons
I Displaced taus
I ATLAS displaced leptons
I Non-isolated leptons Brust, Maksimovic, Sady, Saraswat, Walters, Xin - 1210.3657
I Photon jets Eliis, Roy, Scholtz - 1410.0362
I Emerging jets Schwaller, Stolarski, Weiler - 1502.05409
I Quirks (straight tracks & anomalous bending) Kang, Luty - 0805.4642
I Unknown unknowns insert your paper here
Evans (UIUC) Displaced Leptons February 16, 2016 38 / 39
Comments and PerspectivesKnown unknowns. . .
What more is wanted from experiment?
I Displaced same-flavor leptons
I Displaced taus
I ATLAS displaced leptons
I Non-isolated leptons Brust, Maksimovic, Sady, Saraswat, Walters, Xin - 1210.3657
I Photon jets Eliis, Roy, Scholtz - 1410.0362
I Emerging jets Schwaller, Stolarski, Weiler - 1502.05409
I Quirks (straight tracks & anomalous bending) Kang, Luty - 0805.4642
I Unknown unknowns insert your paper here
Evans (UIUC) Displaced Leptons February 16, 2016 38 / 39
Comments and PerspectivesKnown unknowns. . .
What more is wanted from experiment?
I Displaced same-flavor leptons
I Displaced taus
I ATLAS displaced leptons
I Non-isolated leptons Brust, Maksimovic, Sady, Saraswat, Walters, Xin - 1210.3657
I Photon jets Eliis, Roy, Scholtz - 1410.0362
I Emerging jets Schwaller, Stolarski, Weiler - 1502.05409
I Quirks (straight tracks & anomalous bending) Kang, Luty - 0805.4642
I Unknown unknowns insert your paper here
Evans (UIUC) Displaced Leptons February 16, 2016 38 / 39
Comments and PerspectivesKnown unknowns. . .
What more is wanted from experiment?
I Displaced same-flavor leptons
I Displaced taus
I ATLAS displaced leptons
I Non-isolated leptons Brust, Maksimovic, Sady, Saraswat, Walters, Xin - 1210.3657
I Photon jets Eliis, Roy, Scholtz - 1410.0362
I Emerging jets Schwaller, Stolarski, Weiler - 1502.05409
I Quirks (straight tracks & anomalous bending) Kang, Luty - 0805.4642
I Unknown unknowns insert your paper here
Evans (UIUC) Displaced Leptons February 16, 2016 38 / 39
Comments and PerspectivesKnown unknowns. . .
What more is wanted from experiment?
I Displaced same-flavor leptons
I Displaced taus
I ATLAS displaced leptons
I Non-isolated leptons Brust, Maksimovic, Sady, Saraswat, Walters, Xin - 1210.3657
I Photon jets Eliis, Roy, Scholtz - 1410.0362
I Emerging jets Schwaller, Stolarski, Weiler - 1502.05409
I Quirks (straight tracks & anomalous bending) Kang, Luty - 0805.4642
I Unknown unknowns insert your paper here
Evans (UIUC) Displaced Leptons February 16, 2016 38 / 39
Conclusions
I Many exotic objects are covered, but there are gaps
I Displaced τs from GMSB: well-motivated and weakly constrained
I Sensitivity to τR can be improved in the CMS e±µ∓ searchI Add SF` binsI Add τh binsI Lowered pT thresholdsI Extend d0 > 2 cm
I Add SS` bins (CR contamination)I Allow extra `sI Relax isolation in high d0 binsI Add high pT ,` bins
I Disappearing track searches should consider this benchmarkI Kinked tracks?
I Several models with displaced ee/µµ uncovered at LHC
I A lot of exciting work needs to be done on exotic objects!
Evans (UIUC) Displaced Leptons February 16, 2016 39 / 39
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