Exotica in CMS · 2019. 6. 26. · Exotica in CMS Claudia-Elisabeth Wulz CMS Collaboration Institute of High Energy Physics, Vienna ICNFP 2015 Kolymbari, Crete 25 August 2015 . C.-E

Exotica in CMS

Claudia-Elisabeth Wulz CMS Collaboration Institute of High Energy Physics, Vienna

ICNFP 2015 Kolymbari, Crete 25 August 2015

ICNFP, Aug. 2015 C.-E. Wulz 2

Overview!Selected recent results: -  Dark matter searches

-  Searches with boosted objects -  Weak bosons, tops, Higgs in final state

-  Long-lived signatures

-  Classic narrow resonance searches

EXO-14-004, EXO-12-054, EXO-12-048, EXO-12-047

EXO-14-010, EXO-14-009, EXO-13-007

All CMS public BSM physics results:

https://twiki.cern.ch/twiki/bin/view/CMSPublic/PhysicsResultsEXO

https://twiki.cern.ch/twiki/bin/view/CMSPublic/PhysicsResultsB2G

EXO-12-038, EXO-12-036, EXO-12-034, EXO-12-026, EXO-13-006, EXO-14-012, EXO-14-017

DP-15-017, EXO-14-010, EXO-13-007, EXO-12-059, EXO-12-052, EXO-12-050, EXO-12-049, EXO-12-046, EXO-12-045, EXO-12-024

ICNFP, Aug. 2015 [GeV]χM1 10 210 310

]2-N

ucle

on C

ross

Sec

tion

[cm

χ

-4610

-4510

-4410

-4310

-4210

-4110

-4010

-3910

-3810

-3710

-3610

-1CMS, 90% CL, 8 TeV, 19.7 fb

-1CMS, 90% CL, 7 TeV, 5.0 fb

LUX 2013

superCDMS

CDMSlite

XENON100

COUPP 2012

SIMPLE 2012CoGeNT 2011

CDMS II

CMS

Spin Independent

2Λ

q)µγq)(χµγχ(

Vector

3Λ4

2)νµ

a(Gsαχχ

Scalar

-1CMS, 90% CL, 8 TeV, 19.7 fb

C.-E. Wulz 3

Dark Matter Searches

Contact interaction

q̄

q

DM

DM

q̄

q

DM

DM

Mediator

CMS-EXO-12-048, EPJC 75 (2015) 235 Mediator Mass M [GeV]210 310 410

[GeV

]qg χg

90%

CL

limit

on M

/

0

1000

2000

3000

4000 = M/3Γ = 50 GeV, χM = M/10Γ = 50 GeV, χM

π = M/8Γ = 50 GeV, χM = M/3Γ = 500 GeV, χM = M/10Γ = 500 GeV, χM

π = M/8Γ = 500 GeV, χM contoursqgχg

CMS (8 TeV)-119.7 fb

Spin Independent, Vector

2Λ

q)µγq)(χµγχ(

0.10.2 0.5 1 2 5 10

Select events with ISR –> mono-objects, e.g. mono-jets, mono-Z, mono-γ

Complementary to direct/indirect searches, best for low DM mass and spin-dependent couplings

[GeV]χmWIMP mass 1 10 210 310

]2W

IMP-

nucle

on c

ross

sec

tion

[cm

43−10

42−10

41−10

40−10

39−10

38−10

37−10

36−10χχ

-l+l→χχZ→pp-1 = 8.0 TeV, L = 19.7 fbsPreliminary

CMS

Spin Dependent

CMS mono-Z (D8)

CMS mono-Z (D9)

= 1q = g

χtruncated, g

= 1q = gχ

truncated, g

COUPP 2012SIMPLE 2011

PICASSO

IceCube (WW)

(D8)γCMS mono-

CMS mono-jet (D8)CMS-EXO- 12-054

mono-jets

mono-Z

gq gχ


Dark Matter Searches

(GeV)χM1 10 210 310

)2 (c

mχ

N-σ

-4610

-4510

-4410

-4310

-4210

-4110

-4010

-3910

-3810

-3710

-3610

-3510

-3410

-3310

-3210

2Λ

q)5γµγq) (χ

5γ

µγχ(

: AVO

Spin Dependent

Razor DM

-W+IceCube W

SIMPLE 2012

COUPP 2012-W+Super-K W

(8 TeV)-118.8 fbCMSPreliminary

(GeV)χM1 10 210 310

)2 (c

mχ

N-σ

-4610

-4510

-4410

-4310

-4210

-4110

-4010

-3910

-3810

-3710

-3610

-3510

-3410

-3310

-3210

2Λ

q)µγq) (χµγχ(

: VO

Spin Independent

Razor DM

XENON 100SIMPLE 2012COUPP 2012superCDMSCDMSIILUX 2013


(GeV)χM1 10 210 310

(GeV

)Λ

0

500

1000

1500

2000

2500

3000

3500

4000

4500

5000

90% CL limit: AV EFT operatorµRazor-0Expected limit

expected limitσ 1±

Observed limit

χ < 2mΛ

π/2χ < mΛ

= 80%ΛR

= 1eff

g

= 2eff

g

= 4eff

g

π = 4eff

g


Recent razor analysis of dijet + ETmiss signature

CMS-EXO- 14-004

(GeV)χM1 10 210 310

(GeV

)Λ

0

500

1000

1500

2000

2500

3000

3500

4000

4500

5000

90% CL limit: V EFT operatorµRazor-0Expected limit

expected limitσ 1±

Observed limit

χ < 2mΛ

π/2χ < mΛ

= 80%ΛR

= 1eff

g

= 2eff

g

= 4eff

g

π = 4eff

g

(8 TeV)-118.8 fbCMSPreliminary RΛ quantifies

fraction of events for which EFT hypothesis is still valid geff = √gqgχ


Long-lived Particle Signatures

Long-lived particles are predicted in many BSM scenarios SUSY: GMSB, AMSB, split SUSY, RPV SUSY Hidden valley scenarios

Signatures: Displaced objects Delayed objects Disappearing or kinked tracks Lepton jets Recent examples of searches: Neutral particles decaying to photons (CMS-EXO-14-017) Neutral particles decaying to muons (CMS-EXO-14-012) Heavy stable charged particles (CMS-EXO-13-006)

ICNFP, Aug. 2015

Mass (GeV)10χ∼

100 200 300 400

(cm

)10 χ∼τ

Mea

n Li

fetim

e c

-110

1

10

210

310

410

GMSB SPS8

at 8 TeV)-1(19.7 fbCMS Conversions Exp. at 8 TeV)-1(19.7 fbCMS Conversions Obs.

at 7 TeV)-1(4.9 fbCMS Timing Obs. at 1.96 TeV)-1(2.6 fbCDF Obs.

(TeV)Λ100 150 200 250 300

CMSPreliminary

dxy

χ0

χ1 ~

G ~

photon

e+

e-

ECAL

Beam spot

(Beam axis points out of the page)

C.-E. Wulz 6

Long-lived Neutral Particles Decaying to Photons Model with GMSB: long-lived lightest neutralino decays to gravitino and photon

!!

!!

""1

0

""1

0q~

q~G~

G~

EmissT

~

~

g

g

g

q

q

!!

!!

""1

0

""1

0g~

g~G~

G~

EmissT

~

~

q~

q~

g

g

g

q

q

q

q

Event selection: 2γ, with one converting to e+e-, at least 2 jets, and ETmiss

Scenario: 0.4 cm ≤ cτ ≤ 100 cm

ICNFP, Aug. 2015 CMS-EXO-14-017

transverse impact parameter


Long-lived Neutral Particles Decaying to Muons Topology: Two muons originating from displaced secondary vertex, detected in muon chambers only Limits derived for two specific models: 1)  H0 -> XX -> 4µ (H0 … non-SM Higgs boson, X … long-lived boson with spin 0) 2)  2 squark pairs, with q -> qχ0, long-lived χ0 -> µµν (R-parity violated)

d0: transverse impact parameter

µ reconstruction and selection efficiency

Data: cosmics

CMS-EXO-14-012

This analysis is orthogonal to a previous one that used only the tracker (arXiv:1411.6977) – the two analyses have been combined to improve limits

Signal systematic errors

~ ~ ~


Long-lived Neutral Particles Decaying to Muons

Combined 95% CL upper limits for muon chamber and tracker analyses

[cm]τc-110 1 10 210 310

) [pb

]ν-

µ+µ

→0 χ∼ , 0 χ∼ q

→q~B( )q~ q~ +q~ q~ (

σ

-410

-310

-210

-110

1

(8 TeV)-120.5 fbCMS Preliminary

Observed limits2 = 120 / 48 GeV/cχ∼ / mq~m

2 = 350 / 148 GeV/cχ∼ / mq~m2 = 1000 / 148 GeV/cχ∼ / mq~m2 = 1500 / 494 GeV/cχ∼ / mq~m

)σ1±Expected limits (2 = 120 / 48 GeV/cχ∼ / mq~m

H0 -> XX -> 4µ q -> qχ0, χ0 -> µµν ~ ~ ~

[cm]τc-210 -110 1 10 210 310 410

) [pb

]-µ+

µ →

B(X

X

X)→

(Hσ

-410

-310

-210

-110

1

10

2102 = 400 GeV/cHm

(8 TeV)-120.5 fbCMS PreliminaryObserved limits

2 = 20 GeV/cXm2 = 50 GeV/cXm

2 = 150 GeV/cXm)σ1±Expected limits (

2 = 20 GeV/cXm


Displaced Jets Hidden valley benchmark model: H/Φ -> Φhs -> πvπv with πv ->jj/ll Decays of v-particles must occur via hidden sector mediator as they do not couple directly to SM particles. Topology studied: 2 hadronic jets originating from same displaced vertex.

� �hs

⇡v

⇡v

p

p f

f̄

f̄

fCMS (8 TeV)-118.5 fb

[cm]τX c1 10 210

) [pb

]q

q→

(X

2 X

X) B

→(H

σ

-310

-210

-110 95% CL limits: = 150 GeVXm = 350 GeVXm

)σ 1±Exp. limits (

= 1000 GeVHm

H0 -> X0X0, X0 -> qq -

CMS-EXO-12-038, PRD 91 (2015) 012007


Long-lived Heavy Charged Particles

Tracker (high dE/dx) + µ system (long TOF) Tracker only (charge exchange)

R-hadrons: long-lived gluinos could hadronize to e.g. g-g, g-qq, g-qqq states Stable chargino or stau, etc. If mass greater than about 100 GeV: β < 0.9. Nuclear interactions may lead to charge exchange.

~ ~ ~ _


Long-lived Heavy Charged Particles

(ns) ]τ[ 10

log-15 -10 -5 0 5 10 15 20

Poi

nts

in p

MSS

M L

HC

sub

-spa

ce

1

10

210

310

410Constraints on the pMSSM

3 TeV)≤sub-space (m ExcludedAllowed

-15 -10 -5 0 5 10 15 20Frac

. exc

lude

d

00.20.40.60.8

1

(8 TeV)-118.8 fb

CMS

Reinterpretation of previous results on long-lived chargino production [JHEP 07 (2013) 122] in context of pMSSM (first constraints at the LHC) and AMSB models, based on highly-ionizing and penetrating particles

mass (GeV)±1χ

100 200 300 400 500 600 700 800 900

(ns)

τ ± 1χ

1

10

210

(8 TeV)-118.8 fb

CMS AMSB > 0)µ) = 5, β(tan(

Observed limitExpected limit

σ 1 ±Expected limit σ 2 ±Expected limit

Excluded area

CMS-EXO-13-006


Boosted Objects

Massive final-state particles (mX > 1 TeV mass) with high Lorentz boost (γ > 2) - overlapping jets - jet substructure - non-isolated leptons

New analysis techniques to improve high-mass sensitivity (up to factor ~10) - grooming (remove noise and pile-up) - pruning (remove soft, large-angle particles from jets) - tagging (b, t, W/Z, …) - subjettiness, mass-drop

Low-pT top High-pT top

ICNFP, Aug. 2015

XH

W

b

b

�

!

C.-E. Wulz 13

Boosted Objects: X -> WH

First search in semi-leptonic WH final state

W' mass (GeV)800 1000 1200 1400 1600 1800 2000 2200 2400

p-va

lue

-510

-410

-310

-210

-110


combinedµobs signif, e+

σ1

σ2

σ3

σ4

(GeV)WHM800 1000 1200 1400 1600 1800 2000 2200 2400

Even

ts /

( 100

GeV

)

-210

-110

1

10

210)νData (e

W+jetsW' HVT B(gv=3)WW/WZTopUncertainty

(8 TeV)-119.7 fb

CMSPreliminary

(GeV)W'M1000 1500 2000

WH)

(pb)

→*B

R(W

'95

%σ

-310

-210

-110

1

10

800

ObservedSFull CLσ 1± Expected SFull CLσ 2± Expected SFull CL

WH)→ * BR(W' W'

HVT B(gv=3):xsec WH)→ * BR(W' W'LH model:xsec

(8 TeV)-119.7 fbCMS νµ →Preliminary W

CMS-EXO-14-010

Search strategy close to one for high-mass WW resonances in lνqq final state, with additional b-tag requirements Main backgrounds: W+jets, WW/WZ, tt

_

_


Boosted Objects: X -> ZH -> qqττ Novel analysis feature: τ pair in boosted regime Six search channels: leptonic(τeτe, τeτµ, τµτµ), semi-leptonic(τeτh, τµτh), all-hadronic (τhτh) Different backgrounds according to search channels : Z/γ+jets for leptonic channels, for τeτh, τµτh tt and W+jets, for τhτh QCD Event selection: single jet or HT [GeV]ZHm

0 500 1000 1500 2000 2500 3000

Even

ts /

bin

2

4

6

8

10

12

14

16 Background estimationObserved

+jetsγZ/ and single-toptt

VV (V = Z or W)W+jets

5)×σ = 1.5 TeV, Z'Signal (M

(8 TeV)-119.7 fbCMS

categoryhτµτ

[GeV]ZHm1000 1500 2000 2500

) [fb

]- τ+ τ

→ B

(H

×) q q

→ B

(Z

× Z

H)

→ Z

' →

(pp

σ -210

-110

1

10

210 = 3)

VHVT Model B (g

σ 1±Expected σ 2±Expected

Observed

(8 TeV)-119.7 fbCMS

HcV

g-3 -2 -1 0 1 2 3

V/g Fc2 g

-1

-0.5

0

0.5

1

1 TeV1.5 TeV

Mexpσ

≈ > 7% MthΓ

= 3)V

B (g

(8 TeV)-119.7 fbCMS

HVT model

PLB 748 (2015) 255, CMS-EXO-13-007

_

Combination of 6 search channels


Boosted Objects: X -> WH, VH, VV

Resonance mass [TeV]1 1.5 2 2.5 3

X) [

pb]

→(p

p 95

%σ

-210

-110

1

(EXO-12-025)ν lll→ WZ →X qqqq (EXO-12-024)→ WV →X

qq (EXO-13-009)ν l→ WV →X qqll (EXO-13-009)→ WZ →X

bb (EXO-14-010)ν l→ WH →X (EXO-13-007)ττ qq→ VH →X

qqbb,6q (EXO-14-009)→ VH →X )0 X→(pp THσ)+- X→(pp THσ)++ X→(pp THσ

= 3)V

HVT Model B (gWH)→ BR(X≈WZ) →BR(X

ZH)→ BR(X≈WW) → BR(X≈

, V = W / Z0 / X±X = X

(8 TeV)-119.7 fbCMS Preliminary

ICNFP, Aug. 2015

Resonance mass [GeV]1000 2000 3000 4000 5000 6000 7000

[pb]

A × B ×

σ

-210

-110

1

10

210

310

95% CL upper limitsgluon-gluonquark-gluonquark-quark

StringExcited quarkAxigluon/coloronScalar diquarkS8W’ SSMZ’ SSMRS graviton (k/M=0.1)

(13 TeV)-141.8 pb

CMSPreliminary

C.-E. Wulz 16

Classic Narrow Resonance Searches Example: Dijet spectrum Background estimation: data-driven, parameterization by smooth function Interpretation possible for many exotica scenarios Sensitive beyond the Run I reach for resonances with M > 5 TeV

Resonance mass (GeV)1000 2000 3000 4000 5000

(pb)

A × B × σ

-510

-410

-310

-210

-110

1

10

210

310

410CMS

(8 TeV) -119.7 fb

95% CL upper limits

gluon-gluonquark-gluon

quark-quark

StringExcited quarkAxigluon/coloronScalar diquarkS8W' SSMZ' SSMRS graviton (k/M=0.1)

CMS-EXO-12-059, PRD 91 (2015) 052009 CMS-DP-2015-017, cds.cern.ch/record/2037378


Exotica Limits!March 2015


•  CMS has studied a plethora of Exotica signatures with √s = 7 TeV and √s = 8 TeV data and has derived limits for many scenarios. •  Interesting excesses have been seen – stay tuned for more results at √s = 13 TeV ! •  Sensitivity for New Physics is expected to grow fast during Run II.

Conclusions!

ICNFP, Aug. 2015

Documents

Exotica in CMS · 2019. 6. 26. · Exotica in CMS Claudia-Elisabeth Wulz CMS Collaboration Institute of High Energy Physics, Vienna ICNFP 2015 Kolymbari, Crete 25 August 2015 . C.-E