Path of Various Particles

Path of Various Particles

29

Shin-Shan Eiko Yu

•

Neutral, weakly-interactive, massive, and stable on the distance-scales of tens of meters

•

Dark matter appears as missing transverse momentum in collider detectors

30

What Is Dark Matter at Colliders?

Missing

transverse momentum

7m0m3.5 m

Shin-Shan Eiko Yu

µ

jet

Momentum imbalance ν ME

_T

μ

μ

•

The negative of the total transverse momentum of all observed particles in the detector

31

Missing Transverse Momentum

neutrinos or

dark matter

Shin-Shan Eiko Yu 32

•

Mediator has minimal decay width

•

Minimal set of parameters

•

coupling structure, MMED, mDM, gSM (gq), gDM

Simplified Models for Direct DM Production

q

q

!

!

Mediator gSM

(gq) gDM

MMED

mDM

mDM

Shin-Shan Eiko Yu 32

•

Mediator has minimal decay width

•

Minimal set of parameters

•

coupling structure, MMED, mDM, gSM (gq), gDM

Simplified Models for Direct DM Production

Features of Mediators

Tae Min Hong, LHCP 2017

q

q

!

!

Mediator gSM

(gq) gDM

MMED

mDM

mDM

Shin-Shan Eiko Yu 32

•

Mediator has minimal decay width

•

Minimal set of parameters

•

coupling structure, MMED, mDM, gSM (gq), gDM

Simplified Models for Direct DM Production

Features of Mediators

Tae Min Hong, LHCP 2017

q

q

!

!

Mediator gSM

(gq) gDM

MMED

mDM

mDM

Shin-Shan Eiko Yu 32

•

Mediator has minimal decay width

•

Minimal set of parameters

•

coupling structure, MMED, mDM, gSM (gq), gDM

Simplified Models for Direct DM Production

Features of Mediators

Tae Min Hong, LHCP 2017

q

q

!

!

Mediator gSM

(gq) gDM

MMED

mDM

mDM

Shin-Shan Eiko Yu 32

•

Mediator has minimal decay width

•

Minimal set of parameters

•

coupling structure, MMED, mDM, gSM (gq), gDM

Simplified Models for Direct DM Production

Features of Mediators

Tae Min Hong, LHCP 2017

q

q

q

q

Shin-Shan Eiko Yu 33

Amount of Data We Use

Shin-Shan Eiko Yu 33

Amount of Data We Use

σ_tt ∼ 800 pb N_tt = Lσ_tt

∼ 3.2 ×10⁷

DM Searches with Missing Transverse Momentum Signatures

34

q

q

!

!

Mediator gSM

(gq) gDM

MMED

mDM

mDM

Shin-Shan Eiko Yu 35

Mono-X Diagrams of Direct DM Production

Mono-jet Mono-Z(leptonic) Mono-W/Z(hadronic)

Mono-photon Mono-h (bb, "") Mono-tt/bb

Mono-top

Shin-Shan Eiko Yu

•

Anomalous high MET can be due to:

•

Particles striking sensors in the ECAL photodetectors

•

^{Beam halo}

•

Dead cells in ECAL or HCAL

•

Noise in ECAL or HCAL

36

Challenges of Missing Transverse Momentum

[GeV]

miss

ET

500 1000 1500 2000 2500 3000

Events / 30 GeV

−1

10 1 10 102

103

104

105 ^{Top quark}

EWK

QCD

Data after cleaning

Data before cleaning

(13 TeV, 2016) 12.9 fb-1

CMS

Preliminary

Raman Khurana Ching-Wei Chen

CMS-PAS-JME-16-004

Events passing dijet selection

Shin-Shan Eiko Yu 37

Fake Missing Transverse Momentum: Noise

Shin-Shan Eiko Yu 37

Fake Missing Transverse Momentum: Noise

Shin-Shan Eiko Yu 37

Fake Missing Transverse Momentum: Noise

Shin-Shan Eiko Yu 37

Fake Missing Transverse Momentum: Noise

Shin-Shan Eiko Yu

Events / GeV

−2

10

−1

10 1 10 102

103

104

105

106

(13 TeV) 35.9 fb-1

CMS monojet

Data

inv.

→ H(125)

= 2.0 TeV Axial-vector, mmed

)+jets ν ν Z(

)+jets ν W(l

WW/WZ/ZZ Top quark

+jets γ (ll), γ Z/

QCD

Data / Pred. 0.8 0.9 1 1.1 1.2

[GeV]

miss

pT

400 600 800 1000 1200 1400

Unc.(Data-Pred.) 2−

0 2

killed by MET &

veto of extra objects

PRD 97, 092005 (2018)

•

Rely on MET triggers (offline MET cut ≳200 GeV)

•

Major background from Z(→##)+jets, W(→l#)+jets

38

Mono-X Searches in Hadronic Final State

Shin-Shan Eiko Yu 39

Estimation of Z+Jets Background

Searches for Visible Mediator Decays

40

q

q

q

q

Shin-Shan Eiko Yu

•

^high-pT/HT trigger for large-Mjj, ISR "/jet tag or data with only trigger-level objects (data scouting) for small-Mjj

41

Visible Mediator Searches

q

q

q

q

Mediator with ISR

q

q

q

q

Mediator

600 800 1000 1200 1400 1600 1800 2000

[pb/TeV] jj/dmσd

(13 TeV) 27 fb-1

CMS _Data

Fit

gg (0.75 TeV) qg (1.20 TeV) qq (1.60 TeV)

/ NDF = 20.3 / 21 = 1.0 χ2

Wide Calo-jets < 2.04 TeV 0.49 < mjj

| < 1.3 η Δ

| < 2.5, | η

| 106

105

104

103

102

10 1

−1

10

Dijet mass [TeV]

Uncertainty(Data-Fit)

−32

−−011 2 3

0.6 0.8 1 1.2 1.4 1.6 1.8 2

[pb/TeV] jj/dmσd

(13 TeV) 36 fb-1

CMS _Data

Fit

gg (2.0 TeV) qg (4.0 TeV) qq (6.0 TeV)

/ NDF = 38.9 / 39 = 1.0 χ2

Wide PF-jets > 1.25 TeV mjj

| < 1.3 η Δ

| < 2.5, | η

| 104

103

102

10 1

−1

10

−2

10

−3

10

−4

10

Dijet mass [TeV]

Uncertainty(Data-Fit)

−32

−−011 2 3

2 3 4 5 6 7 8

JHEP 08 (2018) 130

(GeV) mSD

40 60 80 100 120 140 160 180

Events / 5 GeV

0 5000 10000 15000 20000

25000 ^Data W(qq)+jets (^×3)

Total SM pred. Z(qq)+jets (×3) Multijet pred. t/tt(qq)+jets (×3)

=135 GeV

=0.17, mZ'

Z'(qq), gq'

(13 TeV) 35.9 fb-1

CMS

: 500-600 GeV pT

(GeV) mSD

50 100 150

Data/Prediction

0.9 1 1.1

JHEP 01 (2018) 097

Result Interpretation

42

Shin-Shan Eiko Yu 43

Mono-X With Vector/Axial Mediators

Mono-jet

Mono-W/Z(hadronic) Mono-Z(leptonic)

Mono-photon

Shin-Shan Eiko Yu 44

Collider Results Only (Vector Mediator)-Mono-X

Shin-Shan Eiko Yu 45

Collider Results Only (Vector Mediator)

Shin-Shan Eiko Yu 46

If We Use Different Parameter Values

Shin-Shan Eiko Yu 47

Collider v.s. Non-Collider Experiments (SI)

gq=0.25, gDM=1

σ_SI^vector ! 6.9 × 10⁻⁴¹cm² g_qg_DM 0.25

⎛

⎝⎜

⎞

⎠⎟

2 1 TeV M_med

⎛

⎝⎜

⎞

⎠⎟

4 µ_nχ 1 GeV

⎛

⎝⎜

⎞

⎠⎟

2

MMed

mDM

mDM

$

Shin-Shan Eiko Yu 47

Collider v.s. Non-Collider Experiments (SI)

No upper bound Experimental limit

gq=0.25, gDM=1

σ_SI^vector ! 6.9 × 10⁻⁴¹cm² g_qg_DM 0.25

⎛

⎝⎜

⎞

⎠⎟

2 1 TeV M_med

⎛

⎝⎜

⎞

⎠⎟

4 µ_nχ 1 GeV

⎛

⎝⎜

⎞

⎠⎟

2

Shin-Shan Eiko Yu 47

Collider v.s. Non-Collider Experiments (SI)

No upper bound Experimental limit Upper bound limited

by mediator mass (collider energy)

gq=0.25, gDM=1

σ_SI^vector ! 6.9 × 10⁻⁴¹cm² g_qg_DM 0.25

⎛

⎝⎜

⎞

⎠⎟

2 1 TeV M_med

⎛

⎝⎜

⎞

⎠⎟

4 µ_nχ 1 GeV

⎛

⎝⎜

⎞

⎠⎟

2

Shin-Shan Eiko Yu 48

Collider v.s. Non-Collider Experiments (SD)

For the model parameters considered here, collider experiments can probe SD cross sections 2-3 orders of magnitude smaller than the non-collider experiments.

gq=0.25, gDM=1

σ_SD^axial ! 2.4 × 10⁻⁴²cm² g_qg_DM 0.25

⎛

⎝⎜

⎞

⎠⎟

2 1 TeV M_med

⎛

⎝⎜

⎞

⎠⎟

4 µ_nχ 1 GeV

⎛

⎝⎜

⎞

⎠⎟

2

Shin-Shan Eiko Yu 49

CMS Phase-2 Upgrade

Shin-Shan Eiko Yu 49

CMS Phase-2 Upgrade

Shin-Shan Eiko Yu 50

The Detector Lab @ NCU

Grid computing room for AMS, CMS, KAGRA

Space for Scintillator+SiPM detector for muography Cleanroom for Silicon

detector for CMS/sPHENIX

~2000 cores

~500 TB

Space for testing, inspection,

repair and students

~45m²

Cleanroom

~26m²

Service room

~7m²

Buffer room

~10m²

~11m²

~41m²

Shin-Shan Eiko Yu

•

cleanroom ~26m²

•

service + buffer room ~17m²

•

class 1000 with temperature and humidity controlled at 22℃

and relative humidity (RH) 55%

all year round

•

fully operation with pressured dry-air service

51

Cleanroom

Shin-Shan Eiko Yu

•

left self-designed 8-inch probe station used for the large pad silicon sensors

•

right 4-inch probe station used for PHOBOS and CMS Preshower (being upgraded for sPHENIX)

•

A new 8-inch MPI probe station was installed in mid-November for CMS HGCal and sPHENIX

52

Probe Stations

Shin-Shan Eiko Yu

•

Aerotech 1.25x1.25 m² robotic gantry with Labview control.

•

OGP optical 3d measurement

•

Hesse BJ820 automatic Bondjet and DAGE 4000 Bondtester(puller)

•

Manual probe station and picoprobes (not visible in this pic)

•

glue dispensers, mini-gantry, microscope, degassing chamber, Keithley 2410 and tools …

53

Cleanroom Equipments at NTU

Gantry

OGP Bondjet

Puller

mini-gantry Gantry

control

A set of jigs and tooling for 6-inch HGCal module assembly

54

1. Deposit epoxy on Cu baseplate

2. Place gold-plated

Kapton film 3. Deposit epoxy and silver epoxy on Kapton

4.Place sensor on top of Kapton

5. Deposit epoxy on sensor, avoiding opening bond pads

6.Place PCB on top of sensor

在文檔中 Shin-Shan Eiko Yu Department of Physics (頁 42-81)