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High Energy Physics:��fundamental physics�w/ the CMS experiment�at CERN

Speaker: Mia Tosi mia.tosi@unipd.it int 7064

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Martino Margoni

Prof. Associato

Patrizia Azzi

Ricercatrice INFN

Marco Zanetti

Prof. Ordinario

Rocco Ardino

PhD student

Enrico Lusiani

post-doc

Franco Simonetto

Prof. Ordinario

Federica Fanzago

Tecnologa INFN

Sandro Ventura

Tecnologo INFN

Paolo Ronchese

Prof. Associato

Pierluigi Bortignon

Prof. Associato

@UNICA

Mia Tosi

RTDb

Ugo Gasparini

Prof. Ordinario

Paolo Checchia

Emeritus

Jacopo Pazzini

Prof. Associato

Gabriele Bortolato : PhD student

Nicolo’ Lai : PhD student

Sabrina Giorgetti : PhD student

Matteo Migliorini : PhD student

Andrea Bulla : PhD student @UNICA

Nicola Bacchetta : ricercatore INFN

Massimo Benettoni : tecnologo INFN

Antonio Bergnoli : tecnologo INFN

Marina Passaseo : tecnologa INFN

Marco Bellato : tecnologo INFN

Anna Meneguzzo : Emeritus

Dario Bisello : Emeritus

Fabrizio Gasparini : Emeritus

Roberto Carlin

Prof. Ordinario

Tommaso Dorigo

Ricercatore INFN

Andrea Triossi

Prof. Associato

Roberto Rossin

Prof. Associato

Alberto Zucchetta

Ricercatore INFN

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Contacts / website

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Research Activities

- Flavour Physics

- Physics of the Higgs boson and the Standard Model

- Search for new physics signals

- Advanced statistical methods

- Advanced automatic reconstruction

- Advanced automatic event selection

- Advanced detector R&D

see Marco Zanetti’ slides

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introduction

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  • our current description of fundamental phenomena

is incredibly accurate, and it is based on

the Standard Model of particle physics

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introduction

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  • our current description of fundamental phenomena

is incredibly accurate, and it is based on

the Standard Model of particle physics

but plenty of unanswered questions !

..any many other questions are still open

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introduction

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  • our current description of fundamental phenomena

is incredibly accurate, and it is based on

the Standard Model of particle physics

but plenty of unanswered questions !

  • best tool currently available to look for answers is

the Large Hadron Collider at CERN

13.6 TeV

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introduction

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  • our current description of fundamental phenomena

is incredibly accurate, and it is based on

the Standard Model of particle physics

but plenty of unanswered questions !

  • best tool currently available to look for answers is

the Large Hadron Collider at CERN

via the CMS experiment

and its data

- detector to operate

- a new detector to build

- freshly recorded data

to be understood

and calibrated

- new technologies

in the field of Big Data

- lots of exciting physics !

CMS is a unique opportunity for young physicists !

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introduction

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  • our current description of fundamental phenomena

is incredibly accurate, and it is based on

the Standard Model of particle physics

but plenty of unanswered questions !

  • best tool currently available to look for answers is

the Large Hadron Collider at CERN

via the CMS experiment

and its data

CMS is a unique opportunity for young physicists !

DETECTOR

STUDIES

ALGORITHMS

DEVELOPMENT

CMS

main activities

in Padova

PHYSICS

ANALYSES

The CMS Padova group has consistently kept

a leading role in the experiment

w/ many position of responsibilities

in detector construction,

physics analyses, automatic event

reconstruction and selection,

and even providing a spokesperson !

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LHC

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for observing the Higgs boson

and new physics signals

we need an accelerator which maximizes

  • the collisions (centre-of-mass) energy
  • the collisions rate

LHC is the biggest and most powerful

proton-proton collider in the world

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CMS – Compact Muon Solenoid

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multi-porpoise HEP detector

- hermetic

- large acceptance

- very strong magnetic field (3.8 T)

- very precise

particles trajectory measurement

- excellent electromagnetic

energy resolution

- excellent muon reconstruction

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What do we see ?

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opportunities

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energy and luminosity

  • 13 → 13.6 TeV: higher mass reach
  • additional 200 fb-1 (x1.5 wrt Run2)

consolidate Run2 observations

e.g. H→ff, VH, ttH, VV, VBS, tttt, ..

  • separately in different channels
  • differential measurements

⇒ systematics becoming relevant

precision

  • discovery-through-precision
  • work to improve systematics

(calibrations and methods)

  • better detector towards HL-LHC

new phase space

  • push for low thresholds
  • new signatures, e.g. LLP

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Some examples : di-higgs

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Some examples : H coupling

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by measuring the Higgs boson decay rate to a particle,

we infer the interaction strength between

the Higgs field and that particle

these measurements directly test the predicted mechanism

by which particles acquire mass

observe the Higgs decay into muons :

is the next experimental frontier (so-far untested mass scale)

- challenge :

very rare SM process (1/5000 Higgs)

very large SM background (S/B ~ 1/1000)

- opportunity :

very large statistics (Run2+Run3)

+ advanced analyses techniques

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Some examples : VBS (and VBF)

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Trilinear and Quartic Gauge Couplings (TGC, QGC)

precisely determined by SU(2) x U(1) gauge symmetry

Anomalous Gauge Coupling would result in different

- production cross-section

- differential cross-section

Vector Boson Scattering at 13.6 TeV:

is a key test of the SM and a possible

means for highlighting new physics

- challenge :

very rare SM process

complex event topologies

- opportunity :

new strategy for enhancing statistics

liaison w/ theory model

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Some examples : rare process

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new heavy particles can affect some interactions

and make them deviate from the Standard Model prediction

production of a top quark w/ a W boson and a Z boson (tWZ)

sensitive to the presence of new particles

- challenge :

very low cross-section in the SM

- opportunity :

clean signature

large statistics in Run3

liaison w/ theory model

explore the mysteries

of the universe

by pushing the boundaries

of the Standard Model

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Some examples : �matter-antimatter puzzle

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  • the charge-conjugation and parity-reversal (CP) symmetry

is a symmetry between matter and antimatter

  • violation of this CP symmetry was first observed in 1964
  • Sakharov proposed that CP violation is necessary to explain

the observed imbalance of matter and antimatter in the Universe

but the amount of CP violation as predicted by the Standard Model

as well as the observed so far in experiments

is too small to explain the cosmic imbalance

there is an as-yet-unknown sources of CP violation

beyond the Standard Model

CP-violating phase in the Bs system (φs)

is predicted in the Standard Model

and the effects of new physics

could change its value significantly

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Some examples : the future

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The High-Luminosity LHC (HL-LHC), due to start in 2029,

will deliver about x10 data than has been accumulated so far 

to exploit the HL-LHC physics potential,

the CMS collaboration is building an optimised detector

that pushes technologies to new heights

  • sustain the increased luminosity

(greater radiation damage and higher particle rates)

  • new tracker
  • new MIP precision timing detector (30 ps)
  • almost all the existing electronics replaced

High granularity 

the key to achieving the necessary HL-LHC performance

is to enhance the granularity of the detector

reduce the maximum occupancy per readout cell

while considerably increasing the readout bandwidth

and processing power of the trigger system

full particle-flow reconstruction at the hardware-based trigger (at 40 MHz)

precision timing information, which contributes to the high-level-trigger,

is exploited by highly optimised software mostly running on GPUs

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Contacts

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Speaker: Mia Tosi

Office n. 144 edificio Marzolo

Email mia.tosi@unipd.it

Group: CMS Padova cms-Padova@cern.ch