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Studying Gauginos in Supersymmetric Model
at Future 100 TeV pp Collider
Takeo Moroi (Tokyo)
Asai, Chigusa, Kaji, TM, Saito, Sawada, Tanaka, Terashi & Uno
arXiv:1901.10389 [hep-ph]
YUCHE 2019 @ Yonsei University (2019.02.26)
1. Introduction
SUSY particles may be quite heavy (even if they exist)
) [GeV]g~m(
1000 1200 1400 1600 1800 2000 2200
) [G
eV
]0 1χ∼
m(
500
1000
1500
2000
2500
3000
35000 lep. [1712.02332]
0
1χ∼q q→g~
3 b-jets [1711.01901]≥0
1χ∼b b→g~
2 lep. SS [1711.01901, 1706.03731]≥ 3 b-jets +≥0
1χ∼t t→g~
0 lep. + 1 lep. [1712.02332, 1708.08232]0
1χ∼Wq q→g~
2 lep. SS ≥ 7-11 jets + 1 lep. + ≥0
1χ∼WZq q→g~
[1708.02794, 1708.08232, 1706.03731]
3 lep. [1805.11381, 1706.03731]≥2 lep. OS SF + ν∼/l~
via 0
1χ∼)νν(ll/q q→g~
[SUSY-2016-30]τ 1 ≥ν∼/τ∼ via 0
1χ∼)νν/ντ/ττ(q q→g~
[1802.03158]γ 1 ≥0
1χ∼ via G
~/Z)γ(q q→g~
ATLAS Preliminary
-1=13 TeV, 36.1 fbs
All limits at 95% CL
July 2018
)0
1χ∼
)<m(g~m(
800 1000 1200 1400 1600 1800 2000 2200
[GeV]g~m
0
200
400
600
800
1000
1200
1400
1600
[G
eV
]10χ∼
m
CMS
10χ∼q q→g~,g~g~→pp July 2018
(13 TeV)-135.9 fb
Expected
Observed
)miss
T1704.07781 (H
)T21705.04650 (M
)T
α1802.02110 (
Do we have a chance to study SUSY particles at colliders?
⇒ Future circular colliders (FCCs) with ECM ∼ 100 TeV maybe an option
Today, I would like to discuss:
• FCC studies of pure gravity mediation model of SUSYbreaking based on anomaly mediation
• In particular, measurements of gaugino masses
Outline
1. Introduction
2. Model
3. Gauginos at FCCs
4. Gaugino Mass Determinations
5. Summary
2. Model
Mass spectrum of our interest
• Sfermion and Higgsino masses are of O(100) TeV
⇒ Heavy stops are good for mh ≃ 125 GeV
⇒ SUSY CP / flavor problems are relaxed
• Gaugino masses are loop suppressed, and are of O(1) TeV
⇒ Wino can be dark matter
⇒ Gauginos are primary targets of collider experiments
Such a mass spectrum is phenomenologically viable
⇒ What is the underlying theory?
Anomaly mediation + pure gravity mediation[Giudice, Luty, Murayama & Rattazzi; Randall & Sundrum; Ibe, TM & Yanagida;
Ibe & Yanagida; Arkani-Hamed et al.]
MSSM
Higgsinos
Sfermions
Gauginos
D = 6 Kahler interaction
Anomaly mediation
Giudice-MasieroSUSY breaking sector
(No singlet)
• The most general supergravity Lagrangian with Planck-suppressed interactions
• No singlet in SUSY breaking sector
• Scalar masses are of the order of the gravitino mass m3/2
Gaugino masses in the PGM model
M1 ≃g21
16π2
(11m3/2 + L
)
M2 ≃g22
16π2
(m3/2 + L
)
M3 ≃g23
16π2
(−3m3/2
)
L ≡ µ sin 2βm2
A
µ2 −m2A
lnµ2
m2A
• Wino (gaugino for SU(2)L) is likely to be the LSP
•∣∣∣∣∣∣10g
21
3g23mg̃ −
g21g22mW̃
∣∣∣∣∣∣<∼mB̃<∼
10g213g23
mg̃ +g21g22mW̃
Motivation 1: Wino LSP as dark matter
0
0.1
0.2
0.3
1 2 3Wino Mass (TeV)
Non−perturbativePertu
rbativ
e
Ω (
Win
o)
[Hisano, Matsumoto, Nagai, Saito & Senami] [Moroi, Nagai, Takimoto]
• Thermally produced Wino can be DM, if mW̃ ≃ 2.9 TeV
⇒ Can we test such a Wino at colliders?
• Non-thermal production of Wino DM is also possible
Motivation 2: Heavy stops are good for mh ≃ 125 GeV
m2h ≃ m2
Z cos2 2β +3m4
t
2π2v2
log m2t̃
m2t
+A2
t
m2t̃
1− A2t
12m2t̃
[Okada, Yamaguchi & Yanagida; Ellis, Ridolfi & Zwirner; Haber & Hempfling]
[TeV] S
M10
2103
10
[G
eV
]h
m
105
110
115
120
125
130
135
= 10βtan
= 5βtan
= 4βtan
= 3βtan
= 2.5βtan
⇒ The stop masses of O(10− 1000) TeV are suggested
Motivation 3: Cosmological gravitino problemWino Mass = 500 GeV Wino Mass = 1 TeV
He4
DD
He4He (ITG)4He (ITG)4
He / D3
ΩLSP
M2 = 1.0 TeV
M1 = 1.4 TeV
M3 = 3.0 TeV
M2 = 0.5 TeV
M1 = 0.9 TeV
M3 = 2.0 TeV
[Kawasaki, Kohri, TM, Takaesu]
⇒ With m3/2>∼ 10 TeV, the reheating temperature as high as
TR>∼ 109 GeV is possible
⇒ Simple thermal leptogenesis may work[Buchmuller, Di Bari & Plumacher; Giudice, Notari, Raidal, Riotto & Strumia]
Summary of Motivations
• Higgs mass of mh ≃ 125 GeV is easily realized
• Wino can be the LSP, which is a viable candidate of DM
• Cosmological gravitino problem is easily avoided
• Gauge coupling unification is OK
• SUSY CP / flavor problems may be avoided
Hierarchy between the SUSY scale and the EW scale is sizable
⇒ It’s better than the hierarchy between Planck scale andthe EW scale
3. Gauginos at FCCs
Let us consider
• How and how well we can determine gaugino masses
• Possibility to test the scenario
Sample points for MC studies (mW̃ < mB̃ < mg̃)
Point 1 Point 2
m3/2 [TeV] 250 302L [TeV] 800 756
mB̃ [TeV] 3.7 4.1mW̃ [TeV] 2.9 2.9mg̃ [TeV] 6.0 7.0
σ(pp → g̃g̃) [fb] 7.9 2.7
Gluino decay
g̃ → q̄qB̃, q̄qW̃
q~
g~
q
q
B~ q
~
g~
q
q
W~
Assumptions:
• Br(g̃ → qq̄W̃ ) = Br(g̃ → qq̄B̃) = 0.5
• Gluino decays into all the generations universally
Bino decay
B̃ → W∓W̃±, hW̃ 0
B~
W~
B~
h
W~
W
0
In the sample point of our choice:
• B̃ → W̃±W∓ dominates
• B̃ → ff̄W̃± is negligible
Charged Wino decay: W̃± → W̃ 0π±
• ∆mW̃ ≃ 165 MeV
• cτW̃±→W̃ 0π± ≃ 5.8 cmW~
π
W~ 0
Charged Wino may be identified as short high-pT track
• W̃±-tracks can be reconstructed by inner pixel detector
• Requiring W̃±-like tracks, SM background can be reduced
Long-lived W̃± at FCC-hh: case with pp → W̃±W̃±,0j
• Inner pixel detector has several layers at LT<∼ 10− 15 cm
[Saito, Sawada, Terashi & Asai 1901.02987]
2000− 1500− 1000− 500− 0 500 1000 1500 2000
z [mm]
0
50
100
150
200
250
300
350
400
450
500
Ra
diu
s [m
m]
2−10
1−10
1
10
210
310
410
510
610
Nu
mb
er
of ch
arg
ino
de
ca
ys
-1 = 100 TeV, 30 absFCC-hh,
Alternative layout (#3)
0 1 2 3 4 5
Chargino mass [TeV]
Higgsino
Wino
-1=100 TeV, 30 abs discovery, FCC-hh, σ5
-1=14 TeV, 3 absExpected exclusion, HL-LHC (ATLAS),
-1=14 TeV, 3 abs discovery, HL-LHC (ATLAS), σ5
-1=13 TeV, 36.1 fbsObserved exclusion, ATLAS,
Disappearing Track
• FCC-hh may cover the Wino mass up to 4− 5 TeV
• Sensitivity depends on the detector layout
The events of our interest: gluino pair production
• Multi-jets
• Charged Wino track(s), identified by the pixel detector
Beam pipe (IP)
Inner pixex detector
Outer tracker
ECAL
HCAL
Charged Wino
Jet
Expectation for the pixel detector
• 4th or 5th layer at LT ∼ 10− 15 cm
• Timing information is available: δt ∼ O(10 ps)
Timing information can be converted to the Wino velocity
0 0.2 0.4 0.6 0.8 10
0.05
0.1
0.15
0.2
0.25
δ β
/ β
β
δt = 50psec
δt = 40psec
δt = 30psec
δt = 20psec
δt = 10psec
⇒ δβ
β∼ (a few− 10) %× β(true)
4. Gaugino Mass Determinations
Flow-chart of our MC study
MadGraph5 for gluino pair production
ROOT
PYTHIA (decay and hadronization)
Delphes (detector simulation)
Analysis Code
Cuts
Invariant masses
Hemisphere analysis...
Wino velocity smearing
Wino info.
Requirements on signal events:
• Two W̃±-tracks with LT > 10 cm and |η| < 1.5
• p(miss)T > 1 TeV
p(miss)T : Missing pT evaluated only from jets
We assume:
• Charged Wino can be identified if LT > 10 cm
• Velocity resolution of W̃± is 6 %
• There is no error in the charged Wino direction
Wino track can also be used to eliminate SM backgrounds
⇒ Fake track rate ∼ O(10−5) per track
⇒ SM backgrounds are negligible
Measurement 1: Wino mass
• Wino velocity may be determined with timing information
• Momenta of Winos can be estimated using MET infor-mation (if two Wino tracks are observed)
⇔ Momentum is assumed to be carried away by jets andWinos
We determine Wino momenta by solving:
c1n⃗W̃1,T+ c2n⃗W̃2,T
= −p⃗miss ≡ −∑i:jets
p⃗i,T
p⃗W̃1= c1n⃗W̃1
p⃗W̃2= c2n⃗W̃2
Wino mass in terms of observables:
m(rec)
W̃=
1
βW̃±γW̃±|p⃗W̃±| ≡
√1− β2
W̃±
βW̃±|p⃗W̃±|
We use the events with:
• W̃± with LT > 10 cm and β(obs) < 0.8 for reconstruction
• 2nd W̃± track for background reduction
• No isolated lepton
Reconstructed Wino mass
histmwno1
Entries 250
Mean 2952
Std Dev 920.8
Mwno(Gauss) 54.8± 2911
σ 54.8± 695.8
A 2.2± 23.2
C 0.2527± 0.7339
0 2000 4000 6000
Wino Mass (GeV)
0
5
10
15
20
25
30-1#
/ 2
00
Ge
V / 1
0 a
bhistmwno1
Entries 250
Mean 2952
Std Dev 920.8
Mwno(Gauss) 54.8± 2911
σ 54.8± 695.8
A 2.2± 23.2
C 0.2527± 0.7339
Sample Point 1 histmwno1
Entries 103
Mean 3104
Std Dev 1056
Mwno(Gauss) 101.9± 3119
σ 105.3± 752.6
A 1.259± 7.987
C 0.2033± 0.4189
0 2000 4000 6000
Wino Mass (GeV)
0
2
4
6
8
10
-1#
/ 2
00
Ge
V / 1
0 a
b
histmwno1
Entries 103
Mean 3104
Std Dev 1056
Mwno(Gauss) 101.9± 3119
σ 105.3± 752.6
A 1.259± 7.987
C 0.2033± 0.4189
Sample Point 2
• True value: 2900 GeV
• Fit: Gaussian + constant
Reconstructed Wino mass: pp → W̃+W̃−j
• True Wino mass: 2900 GeV
• βW̃± < 0.8
• p(miss)T > 1 TeV
0 2000 4000 6000
Wino Mass (GeV)
0
1
2
3
4
5
-1#
/ 2
00
Ge
V / 3
0 a
b
Wino Mass (10cm & 10cm)
histmwno1
Entries 32
Mean 2769
Std Dev 658.1
Mwno(Gauss) 113.8± 2775
σ 80.5± 643.8
A 0.859± 3.966
C 02− 2.787e±10 − 6.106e
Wino Mass (10cm & 10cm)
⇒ δm(obs)
W̃≃ 130 GeV (with L = 30 ab−1)
Measurement 2: Bino mass
B~
W~
W : fat jet
: short high p trackT
• Wino momentum is known (if LT is long enough)
• W -jet may be identified as a fat jet
⇒ We use jets with mj ∼ mW
Reconstructed Bino mass (assuming mW̃ is known)
m(rec)
B̃=
√(mW̃uW̃± + pW )2 with uW̃± = (γW̃±, βW̃±γW̃±n⃗W̃±)
Jet mass distribution (for Point 1)
40 60 80 100 120 140 160 180 200Jet Mass (GeV)
0
2000
4000
6000
8000
10000
-1#
/ 2 G
eV /
10 a
b
We require:
• W̃± with LT > 10 cm and β(obs) < 0.9 for reconstruction
• Jet with 70 GeV < mj < 90 GeV
Reconstructed Bino mass (using true Wino mass)
histmbno1
Entries 581
Mean 4232
Std Dev 706.3
Mbno(Gauss) 9.3± 3628
σ 10.80± 70.38
A 2.90± 19.26
C 0.217± 3.917
3000 4000 5000 6000
Bino Mass (GeV)
0
5
10
15
20
25
30
-1#
/ 3
0 G
eV
/ 1
0 a
bhistmbno1
Entries 581
Mean 4232
Std Dev 706.3
Mbno(Gauss) 9.3± 3628
σ 10.80± 70.38
A 2.90± 19.26
C 0.217± 3.917
Sample Point 1 histmbno1
Entries 264
Mean 4353
Std Dev 701.9
Mbno(Gauss) 11.3± 4060
σ 10.80± 62.51
A 2.08± 10.51
C 0.137± 1.621
3000 4000 5000 6000
Bino Mass (GeV)
0
2
4
6
8
10
12
-1#
/ 3
0 G
eV
/ 1
0 a
b
histmbno1
Entries 264
Mean 4353
Std Dev 701.9
Mbno(Gauss) 11.3± 4060
σ 10.80± 62.51
A 2.08± 10.51
C 0.137± 1.621
Sample Point 2
• True value: 3660 GeV (Pt.1) / 4060 GeV (Pt.2)
• Fit: Gaussian + constant
Measurement 3: Gluino mass (with hemisphere analysis)
pp
j
j j
j
j
jj
W~
W~
Hemisphere 1
Hemisphere 2
Reconstructed gluino mass
m(rec)g̃ =
√P 2Hemisphere with PHemisphere ≡ PW̃± +
∑j∈H
pj
Hemisphere analysis with two observed Wino tracks
• Two charged Winos are assigned to different hemispheres:
W̃±A ∈ HA (A = 1, 2)
• For each high pT jet:ji ∈ H1: if d(pH1
, pji) < d(pH2, pji)
ji ∈ H2: if d(pH2, pji) < d(pH1
, pji)
Momentum of A-th hemisphere HA
pHA= pW̃±
A+
∑ji∈HA
pji
Distance function[See De Roeck (Editor), CMS Physics TDR]
d(pH , pj) =(EH − |pH | cos θHj)EH
(EH + Ej)2
We study the invariant mass of hemispheres containing W̃±
• Two long enough W̃± tracks
• No isolated lepton
• We use jets with |η| < 2
Hemisphere analysis with two charged Winos
• Momenta of Winos are determined using missing momen-tum information
• Each hemisphere contains one W̃± (and jets)
• Invariant mass of the hemisphere is regarded as (recon-structed) gluino mass
Reconstructed gluino mass (with true Wino mass):
histmgno1
Entries 756
Mean 6242
Std Dev 1782
Mgno(Gauss) 54.7± 5932
σ 49.3± 1224
A 2.17± 42.24
C 0.277± 1.687
5000 10000
Gluino Mass (GeV)
0
10
20
30
40
50
60
-1#
/ 2
00
Ge
V / 1
0 a
bhistmgno1
Entries 756
Mean 6242
Std Dev 1782
Mgno(Gauss) 54.7± 5932
σ 49.3± 1224
A 2.17± 42.24
C 0.277± 1.687
Sample Point 1 histmgno1
Entries 348
Mean 6883
Std Dev 1918
Mgno(Gauss) 100.0± 6631
σ 85.7± 1511
A 1.15± 15.54
C 0.2231± 0.7323
5000 10000
Gluino Mass (GeV)
0
5
10
15
20
25
-1#
/ 2
00
Ge
V / 1
0 a
b
histmgno1
Entries 348
Mean 6883
Std Dev 1918
Mgno(Gauss) 100.0± 6631
σ 85.7± 1511
A 1.15± 15.54
C 0.2231± 0.7323
Sample Point 2
• True value: 6000 GeV (Pt.1) / 7000 GeV (Pt.2)
• Fit: Gaussian + constant
5. Summary
Gaugino mass determinations may be possible
Sample Point 1 (with L = 10 ab−1):
δmB̃ δmW̃ δmg̃
δm(stat)
X̃8GeV 61GeV 59GeV
Due to δmW̃ 61GeV − 61GeV
Total 62GeV 61GeV 85GeV
⇒ Test of the model∣∣∣∣∣∣10g21
3g23mg̃ −
g21g22mW̃
∣∣∣∣∣∣<∼mB̃<∼
10g213g23
mg̃ +g21g22mW̃
Information about the mechanism of SUSY breaking
Sample Point 1
Sample Point 1
⇒ Determination of m3/2, |L|, · · ·⇒ Impact on cosmology
FCC-hh can have significant impact on BSM studies
• Discovery
• Measurements