Higgs and Beyond at the LHC Selected topics mostly on Higgs physics - PowerPoint PPT Presentation

Higgs and Beyond at the LHC Selected topics mostly on Higgs physics at the LHC, some comments about Run 2 Marumi Kado Laboratoire de l’Accélérateur Linéaire Orsay (France) Seminario del Dipartimento di Fisica dell’Università di Pisa (21/10/2014)

Preliminary remarks and Disclaimer ‐ The LHC physics program is incredibly vast! ‐ This talk will mostly be centered on Higgs physics but will not cover all aspects of Higgs physics ‐ We have not fully done our home work for Run 2 projections (we have Run 3 and HL ‐ LHC) !

The Run 1 of the LHC has been extremely productive Conference Notes Papers Similar numbers for CMS Similar numbers for CMS … and successful!

The two main outcomes of the LHC (so far) ‐ The celebrated discovery of the Higgs boson ! ‐ And nothing else… (surprise despite the absence of deviations in precision EW and flavor measurement)

PDG, review of Particle Physics 10 0 Local p 1 A Textbook and Timely  1 -1 10  2 -2 10  3 -3 10 -4 10  4 -5 10 Discovery -6 10  5 -7 10 -8 10  -9 6 10 -10 10 Summer 07/2011 s = 7 TeV -11 10 CMS Prel. [20]   -12 -1 10 Ldt 1 fb ATLAS Prel. [21] -13 10 10 0 Local p 1  Summer 2011: EPS and Lepton ‐ Photon 1 • -1 10  2 -2 10  3 -3 10 -4 First (and last) focus on limits (scrutiny of the p 0 ) 10  4 -5 10 -6 10  5 -7 10 -8 10  -9 6 10 • December 2011: CERN Council -10 Spring 2012 10 s = 7 TeV -11 10 CMS [25]  -12  -1 10 Ldt 5 fb ATLAS Prel. [28] -13 10 First hints 10 0 Local p 1  1 -1 10  2 -2 10  3 -3 10 • Summer 2012: CERN Council and ICHEP -4 10  4 -5 10 -6 10  5 -7 Discovery! 10 -8 10  -9 6 10 -10 10 Council/ICHEP 07/2012 7 and 8 TeV -11 10 CMS Prel. [23]  -12  -1 10 Ldt 10 fb ATLAS Prel. [22] -13 • December 2012: CERN Council 10 10 0 Local p 1  1 -1 10 Begining of a new era  2 -2 10  3 -3 10 -4 10  4 -5 10 7 and 8 TeV -6 10  5 -7 10   -1 Ldt 25 fb -8 10 6   -9 6 10 HCP/Council 2012 -10 10 -11 10 CMS Prel. [24]  7 -12 10 ATLAS Prel. [23] -13 10 5 110 115 120 125 130 135 140 145 150 m [GeV] H

8 October 2013 The Royal Swedish Academy of Sciences has decided to award the Nobel Prize in Physics for 2013 to François Englert and Peter Higgs 
 “for the theoretical discovery of a mechanism that contributes to our understanding of the origin of mass of subatomic particles, and which recently was confirmed through the discovery of the predicted fundamental particle, by the ATLAS and CMS experiments at CERN’s Large Hadron Collider”

ATLAS LHC 8 October 2013 The Royal Swedish Academy of Sciences has decided to award the Nobel Prize in Physics for 2013 to François Englert and Peter Higgs 
 “for the theoretical discovery of a mechanism that contributes to our understanding of the origin of mass of subatomic particles, and which recently was confirmed through the discovery of the predicted fundamental particle, by the ATLAS and CMS experiments at CERN’s Large Hadron Collider” CMS

Years of Design, Construction and Commissioning of the LHC

Years of Design, Construction and Commissioning of Experiments

20 Years, projecting, constructing and Simulating… Latin American Workshop on HEP 10

4  event … Standard EW only or Higgs? 2011 7 TeV Latin American Workshop on HEP 11

Center-of-Mass Energy (Nominal) 14 TeV ? Center-of-Mass Energy (close to nominal) 13TeV LHCb ATLAS Center-of-Mass Energy (2012) 8 TeV CMS ALICE Center-of-Mass Energy (2010-2011) 7 TeV 12

First LHC Run Completed Event taken at random (filled) bunch crossings … in LS1 Parameter 2010 2011 2012 Nominal C.O.M Energy 7 TeV 7 TeV 8 TeV 14 TeV Bunch spacing / k 150 ns / 368 50 ns / 1380 50 ns /1380 25 ns /2808  (mm rad) 2.4-4 1.9-2.3 2.5 3.75  * (m) 3.5 1.5-1 0.6 0.55 L (cm -2 s -1 ) 2x10 32 3.3x10 33 ~7x10 33 10 34

The first LHC run 2010 2011 ] -1 35 O(2) Pile ‐ up events Delivered Luminosity [fb ATLAS Online Luminosity 2012 2010 pp s = 7 TeV 30 2011 pp s = 7 TeV 23 fb -1 Event taken at random 2012 pp s = 8 TeV at 8 TeV (filled) bunch crossings 25 150 ns inter ‐ bunch spacing 4 th July seminar 20 and ICHEP 15 2011 5.6 fb -1 2010 10 at 7 TeV 0.05 fb ‐ 1 2011 5 at 7 TeV O(10) Pile ‐ up events 0 Apr Jul Jan Oct Month in Year Event taken at random (filled) bunch crossings 50 ns inter ‐ bunch spacing Design value (expected to be reached at L=10 34 !) 2012 O(20) Pile ‐ up events 14 50 ns inter ‐ bunch spacing

Detector Challenges (Highlights) ‐ Trigger Challenge : How to select 400 out of 20M events per second while keeping the interesting (including unknown) physics ‐ Computing Challenge : How to reconstruct, store and distribute 400 increasingly complex events per second and their simulation (over 100 PB per experiment) ‐ Analysis Challenge : Maintain high (and as much as possible stable) reconstruction and identification efficiency for physics objects (e,  ,  , jets, E T mi s , b ‐ jets) up to the highest pile ‐ up

The Standard Model With one doublet of complex scalar field The elegant gauge sector The ugly Higgs sector - Non universal interactions not governed by a symmetry + Dark matter ? + BSM ? - Bares most of the free parameters of the SM … but testable!

(and masses of fermions) ~6 orders of magnitude Neutrinos are not even on the scale! Not explaining the flavor Hierarchy Replacing mass terms by Yukawa couplings

(and masses of fermions) Proof of condensate ! (and masses of gauge bosons) The Gift of Nature at 125 GeV

(and masses of fermions) Proof of condensate ! (and masses of gauge bosons) V (  )   2  *    (  *  ) 2 v    2 

The discovery did not exactly come as a surprise! Prediction of the Model Protected by cutsodial symmetry g 2 M W   g 2   cos 2  W g 2   M Z F . Wilczek at the LEP Celebration : The Higgs mechanism is corroborated at 75%

The Higgs and the No Loose theorem * at the LHC The longitudinally polarized amplitude of: Does not preserve perturbative unitarity. Introducing a Higgs boson ensures the unitarity of this process PROVIDED that its mass be smaller than : ~ 1 TeV Still very important to check : Just starting… - Overall same sign WW - 4.5 s observed (3.4 s exp.) - Still a long way to go to precisely test polarized VBS *approximate No Loose theorem

The mass did not exactly come as a surprise either! Precision EW data  r  log( m H ) m W m H ~ 90 GeV Is there a Higgs?

Why “nothing else” came as a fundamental observation and a surprise? The Hierarchy Problem, Naturalness and fine tuning The Higgs potential is fully renormalizable, but… Loop corrections to the Higgs boson mass… …are quadratically divergent : Not really a problem unless there is a scale L ! 0  m  ... H  m m (R. Barbieri)

Possible Solutions 1.- Elegant: Mechanisms that protect the Higgs boson mass - Supersymmetry - Composite Higgs, Higgs as a pseudo goldstone boson - Large extra dimensions All more or less in trouble (G. Altarelli) 2.- The multiverse and accepting fine tuning: - The anthropic principle - Near criticality of our universe (metastable vacuum)

Nothing Else (1)

Nothing Else (2)

Landscape Redefined Flurry of new ideas ! Precision Rare decays Z   ‐ Mass and width ‐ Muons  ‐ Coupling properties ‐ LFV  , e  ‐ Quantum numbers (Spin, CP) ‐ J  Z  WD etc… ‐ Differential cross sections ‐ ‐ Off Shell couplings and width 0 ‐ Interferometry Tool for discovery ‐ Portal to DM (invisible Higgs) Is the SM minimal? ‐ Portal to hidden sectors ‐ 2 HDM searches Portal to BSM physics with H 0 ‐ ‐ MSSM, NMSSM searches in the final state (ZH 0 , WH 0 , H 0 H 0 ) ‐ Doubly charged Higgs bosons …and More! One of the first goals : focus our ‐ FCNC top decays efforts to extract most of the ‐ Di ‐ Higgs production physical content of our data! ‐ Trilinear couplings prospects ‐ Etc…

QCD

QCD Testing predictions over 8 orders of magnitude !

EW