icrea - results from the lhc run ii. mario martinez

Results from the LHC Run II

Mario Mar5nez

68th ICREA Colloquium, Barcelona, November 2015

Outline •  The SM in 30´´

•  Few basic ideas on modern HEP

•  CERN, LHC, ATLAS

•  The success of Run I Physics

•  First Run II Results from ATLAS

•  Notes on Prospects

Disclaimer:

Many many results exist that I will not show…

LHC (running…)

The Standard Model (SM)

H

InteracCons mediated by bosons

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1

10-‐40 10-‐5

10-‐2

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UnificaCon of forces Higgs mechanism makes the small range and weak interacCon (massive Ws and Z )

Same Cme allows for fermion masses

€

σ ∝1Q4

€

σ ∝1

(Q2 + MW2 )2

We are here

H

A world without mass ?

€

a0 = 1αem me

(natural units)

€

GF ∝ 1MW

2

Without giving masses to fermions it would be impossible to form stables atoms

Light W ? Faster reacCons and a Cold Universe

The Sun using Neutrinos

106 cm-‐2 s-‐1

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The Standard Model (SM)

H The Higgs mechanism allows to explain the origin of the mass of the particles in the SM and at the same time explains weakness of the weak interaction…

€

mγ = 0 mg = 0mW = 80GeVmZ = 91GeVmH =125 GeV

Higgs Mechanism

Fermion Masses Most of the free parameters in the SM model come from here

Why such a mass hierarchy ?

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Mass F = M a

E = M c2 Mass as a form of energy

Protón

(uud)

Only 2% of the proton mass is due to quarks…most of it is QCD confinement energy

I. Newton

A. Einstein

Accelerators ..as huge microscopes

€

10−19mThe proton-‐proton collisions probe distances down to

?

ParPcles behave as waves… E = hν h Planck const. λ= h /|p|

Quantum Field Theory •  AnCma^er

–  ParPcle-‐ (anP) parPcle annihilaPon produces pure energy

–  Energy can then transform into new kind of maYer

•  Virtual ParCcles

–  InteracPons are understood and the “exchange” of virtual parPcles

•  Probability –  For each reacPon different final

states are possible according to a given probability to be produced

E = m c2

e+ e-‐

€

E 2 − p2 ≠ m2

€

ΔEΔt ≥ h

27 Km 1232 high-‐tech superconducCng dipole magnets

(at 1.8 K…the coldest (and coolest) place in the universe)

proton – proton 7-‐8 TeV in Run I (2010 – 2012) (13 TeV in Run II) (2015 -‐-‐ )

Approved in 1994

(at 99.999999% of the speed of light)   bunches of 1011 protons collide every 25 ns   109 interacCons per second/experiment

also Pb-‐Pb collisions (1 month/year)

LHC construcCon

LHC ConstrucCon

ATLAS LHC will run for 15 years.. A total of 6 1015 collisions

Hadron Calorimeter (1993 )

Big contribuCon to TileCal in ATLAS

 R&D for design of prototype  ConstrucCon of 1/3 TielCal (Barrel-‐C)

 Understanding of test-‐beam data  Design/construcPon/maintenance of calibraPon electronics (Cs137 & MB)  Study of TileCal Performance  TileCal DQ Monitoring  ContribuPon to Run CoordinaPon

ADCs and RB models designed and built at IFAE

IBL ConstrucCon Final stave assembly done at CERN:

IBL Stave assembly

CNM 3D sensors

Barcelona made a key contribuCon to the Pixel: the most complex detector of ATLAS (and using 3D)

Final IBL stave being mounted 26 March 2014

The ATLAS Experiment selects ONLINE the most interesCng events out of the 109 interacCons/second

ATLAS output rate of 400 Hz (1.5 Mb/event)

Physics Menu

The collision results are typically driven by uninteresCng events   InteresCng events have small probabiliCes to occur   Need for accumulaCng a huge number of collisions

N events = σ x Luminosity

€

1b =10−28m

LHC Performance (2010-‐2012) Spectacular LHC performance (rapid increase of data samples)

..als… rapid increase of pile-‐up condiCons

LHC ended pp run at 7+8 TeV aler delivering more than 28 m-‐1

…back in 2015 with 13 TeV collisions

MulCple InteracCons

Mean Number of Interactions per Crossing0 5 10 15 20 25 30 35 40 45

/0.1

]-1

Rec

orde

d Lu

min

osity

[pb

020406080

100120140160180

Online LuminosityATLAS> = 20.7!, <-1Ldt = 20.8 fb = 8 TeV, s

> = 9.1!, <-1Ldt = 5.2 fb = 7 TeV, s

Up to 40 interacCons / crossing

(requires enormous efforts to understand the reconstrucCon of the physics objects…)

Z µµ events with 20 interacCons on top

Summary QCD/EWK/Top Physics

29

Resonances..

E = M c2

e+ e-‐

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You just learnt we can transform energy in new parCcles… but what about if they decay immediately ?

If the energy in the collision comes close to the mass of the (unknown) mediated parCcle a resonance (a peak of events) is observed…

And this is the way to discover new parCcles

Want a Nobel?...find a resonance

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Building up the peaks..

Higgs !! As in Moriond 2013 E

vent

s / 2

GeV

2000

4000

6000

8000

10000

H

-1Ldt = 4.8 fb = 7 TeV s-1Ldt = 20.7 fb = 8 TeV s

ATLAS

Data 2011+2012=126.8 GeV (fit)

HSM Higgs boson mBkg (4th order polynomial)

[GeV]m100 110 120 130 140 150 160E

vent

s - F

itted

bkg

-200-100

0100200300400500

!"#$%&!!'(() (*) (+) (,) (-)./

".01&!2

$3456$7!89$:6;!/!(<-!#$%

)

()))

*)))

+)))

,)))

-))) =>6>.01!?361@4!?36!AB'CB:$:6

"(±"*±

!"D%E&F(!G!H!I$%J!K!G!(L<M!NO;!"D%E&F(!G!P!I$%J!K!G!-<(!NO;

AD.!QR$S3'3:>RT

A mass peak in the vicinity of 125 GeV

Higgs !!

[GeV]4lm100 150 200 250

Even

ts/5

GeV

0

5

10

15

20

25

30

35

40

-1Ldt = 4.6 fb = 7 TeV s-1Ldt = 20.7 fb = 8 TeV s

4lZZ*HData 2011+ 2012SM Higgs Boson

=124.3 GeV (fit)H mBackground Z, ZZ*

tBackground Z+jets, tSyst.Unc.

ATLAS

[GeV]4lm80 100 120 140 160 180

Even

ts /

3 G

eV

0

5

10

15

20

25

30

35Data

Z+X

,ZZ*Z

=126 GeVHm

CMS Preliminary -1 = 8 TeV, L = 19.6 fbs ; -1 = 7 TeV, L = 5.1 fbs

A mass peak in the vicinity of 125 GeV

H ZZ* 4l

8th Oct. 2013

Higgs at the PDG

Latest Higgs Results If it looks like a duck, swims like a duck, and quacks like a duck…

arXiv:1507.04548 (July 2015)

38

The Standard Model (i.e., the need for new physics)

H

•  Who ordered 3 generations? •  Origin of different masses ? •  Matter/Anti-Matter ?

•  What about Gravity? •  very very weak and only relevant at planetary/cosmological levels

QED/GRAVITY strength ~ 1036

•  Hierarchy Problem … •  Unification at Large Scale? •  Dark Matter in the Cosmos? • ………

New Physics (!) O(TeV) scale phenomenology

The rotaCon of the stars around the center of the galaxies is not consistent with the amount of mass observed (L/M raCo)SUN

Collisions of clusters of galaxies

Large distorCon of the imagines of distant galaxies due to gravitaCon lensing indicaCon of DM in galaxy clusters

GravitaConal Lensing

Considered the ulCmate demonstraCon of the presence of Dark Maêr since this does not involve Newton’s Law

Evidence for Dark Maêr

Spherical dark maêr halo

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Planck (20 March 2013) arXiv:1303.5062v1

CMB radiaCon

380.000 years

13.82 billion years

Super-‐symmetry (SUSY) In the SM the parPcles are classified as fermions of bosons according to the spin of the parPcle SUSY predicts that for

each parPcle in the SM there is a super-‐partner with different spin configuraPon

Examples :

electron (fermion) s-‐electron (boson) quark (fermion) s-‐quark (boson) gluon (boson) gluino (fermion)

So, SUSY DOUBLES the spectrum of parPcles

  SUSY parCcles are heavy and (if exist) could be produced at colliders

Strong

Weak

Electromagnetic

Unification of Forces & SUSY

1.  Squarks and Gluinos are heavy

2.  mixing of third generation leads to light stop and sbottom

3.  good candidate for Dark Matter

4.  One higgs is very light ( < 135 GeV)

SUSY before LHC era (2010)

Dark Ma^er search with Mono-‐jets

45

Pillar of LHC Physics Program for Run II

gluon

EPJC 75 (2015) 299

Inclusive Searches MulCple-‐jets and large ETmiss

€

meff = ETmiss +HT

HT = pTjets∑

SIMPLIFIED SCENARIO

JHEP09(2014)176

2 jets

6 jets

2 jets

MSUGRA

Background from 1 lepton b-‐tag/veto & photon CRs with similar jet and kinemaCc selecCons as in SRs

46

“Natural SUSY 2012”

 Light higgsinos

 Light stop (t1 < 1 TeV)

 Light gluinos (< 1-2 TeV)

One light stop and sbo^on ….rest of sparCcles can be decoupled….

(same weak isospin mulPplet) 47

Summary Searches for Stop (different mass hierarchies, simplified models)

Exclusion for m(~t1) < ~720 GeV for massless LSP Exclusion up to m(LSP) ~280 GeV

arXiv:1506.08616

48

10/11/15 49

No hint for SUSY ?

50

Non-‐SUSY Searches

Extra dimensions, q*, new bosons, vector-‐like quarks, lepto-‐quarks,..

Large Extra Dimensions

52

g,q

g,q Jet,γ

G Extra spaCal dimensions explain the apparent weakness of Gravity (relevant scale ~TeV)

No hint for BSM ?

53

Great Success of the SM… But lots of remaining quesCons..

naturalness dark maKer maKer/anMmaKer asymmetry the flavor/family problems unificaMon of coupling constants …….

54

Things to keep an eye on

Eur. Phys. J. C75 (2015) 318

arXiv:1504.04605

high-‐mass diboson resonances with boson-‐tagged jets

2 SS leptons + HT +b-‐jets + MET

Z + jets+ MET

Few sigma effects calling for more data….

arXiv:1506.00962

55

56

?

The discovery of New Physics requires more energy and more data ………

Run II has started……

57

The physics gain 8 TeV 13 TeV

NO surprising.. this is just PDFs

But tells you nicely what we already know

•  Huge improvement at the edge of phase space •  Searches should be priority 1 in first 6-‐12 months

Consider this an opCmisCc view as it does not include realiCes as

Background composiCon Pileup Data ValidaCon MC simulaCon ……..

58

The physics gain 8 TeV 13 TeV

NO surprising.. this is just PDFs

But tells you nicely what we already know

•  Huge improvement at the edge of phase space •  Searches should be priority 1 in first 6-‐12 months

Consider this an opCmisCc view as it does not include realiCes as

Background composiCon Pileup Data ValidaCon MC simulaCon ……..

Q* and QBH factors 56 – 370 Gluino producCon factor 46 Stop/Sbo^om producCon factor 8 ^H factor 3.9 H(ggF) factor 2.3

59

Early 13 TeV Results ATLAS-‐CONF-‐2015-‐04

Going beyond Run I sensiCvity

80 pb-‐1

60

SUSY/ExoCcs (Some PR plots @ 13TeV)

Inclusive SUSY

Monojet

Di-‐photons Z-‐prime

W-‐prime

61

SUSY prospects (2015-‐6) ATL-‐PHYS-‐PUB-‐2015-‐005

Assuming 20% uncertainty on backg. As inspired by 8 TeV analyses

A hint for SUSY signal sCll possible if the SUSY parCcles are around the corner

62

LHC Plan Producción 174M Higgs

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Final Notes

64

El LHC almost doubles the centre-‐of-‐mass energy in 2015 8 TeV 13 TeV

(about 4 m-‐1 in 2015…we need more)

Cross secCon for stop (0.9 TeV mass) pair producCon @ 13 TeV = 12 x @ 8 TeV

Ready for a new discovery ?

More energy and more data !

Hierarchy Problem From EWK to Planck scale ?

H f

Already a serious problem at 5 TeV scale (cancellation among top, gauge and Higgs loops)

This kind of conspiracy has name in Physics…

New Symmetry ? (taken from C. Quigg, hep-ph/0704.2232)

EWK scale: 102 GeV

Gravity scale: 1019 GeV

..nothing in the middle ??? …

SuperSymmetry vs Higgs

• Fermion/Boson symmetry

• Exact cancellaCon between fermion & boson loops for Higgs

..SUSY must be broken….. model-‐dependent phenomenology

Double Spectra of ParCcles

..will mix to form mass eigenstates..

Higgs sector with 2 doublets

G G ~

67

QBH (producCon of Black Holes in models with extra spaCal dimensions)

JHEP08(2014)103 JHEP 07 (2015) 032

Lepton + Jets MulCJets

Spectacular Events.. Large MulCpliciCes of Jets and Leptons…. No surprises yet 68

Dileptons g,q

g,q

f,V

f,V

G

Limits on RS (ED) Graviton mass vs coupling  95% CL exclusion in the mass range MG = 1.2 TeV – 2.7 TeV

Phys. Rev. D. 90, 052005 (2014)

Limits on SSM and E6 GUT inspired models  MZ’ (SSM) < 2.86 TeV excluded  MZ’ (E6) < 2.4 TeV – 2.6 TeV excluded

69

Dijets Phys. Rev. D. 91, 052007 (2015)

p-‐value = 0.027

Mjj = 5 TeV

Excited quarks with mass < 4 TeV excluded at 95% CL

Bump hunCng…

Dijet mass spectrum fi^ed to the funcConal form

70

HL-‐LHC prospects ATL-‐PHYS-‐PUB-‐2013-‐011 ATL-‐PHYS-‐PUB-‐2014-‐010

Will be in the posiCon to “kill natural SUSY”

SensiCvity up to 3 – 3.5 TeV

71

HL-‐LHC prospects ATL-‐PHYS-‐PUB-‐2013-‐011 ATL-‐PHYS-‐PUB-‐2014-‐010

Will be in the posiCon to “kill natural SUSY”

SensiCvity up to 1 – 1.5 TeV

72

HL-‐LHC prospects ATL-‐PHYS-‐PUB-‐2015-‐032

SUSY Weakly interacCng

SensiCvity up to 1.1 TeV

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Q* and QBHs ATL-‐PHYS-‐PUB-‐2015-‐004

6 TeV Q* 10 TeV QBH

Large increase in sensiCvity (it happens early on)

74

HL-‐LHC prospects Higgs couplings (assuming SM ΓH) •  2-‐5% in most cases •  10% for rare processes (H μμ, ^H ^γγ)

•  may see Higgs self couplings ? (1.3 sigma significance)

ATL-‐PHYS-‐PUB-‐2014-‐019 ATL-‐PHYS-‐PUB-‐2014-‐016

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icrea - results from the lhc run ii. mario martinez

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