1. THE STATUS OF THE BSM SCENARIOS (AFTER THE FIRST LHC PHASE) STEFAN POKORSKI, UNIVERSITY OF WARSAW

2. LHC 7-8 TeV A GREAT TRIUMPH: 125 GeV HIGGS DISCOVERY A PARTICLE APPARENTLY JUST AS THE ELEMENTARY HIGGS BOSON PREDICTED BY THE SM IS DISCOVERED! „APPARENTLY JUST” IS VERY IMPORTANT! TO APPRECIATE ALL THAT LET’S REMEMBER THE FOLLOWING….

3. The Brout-Englert-Higgs mechanism in the gauge theory of electroweak interactions needs additional interactions with spontaneously broken GLOBAL symmetry e.g SU(2)xSU(2)  SU(2) The BEH mechanism: Goldstone bosons become the longitudinal modes of the gauge bosons W, Z which acquire masses.

4. Simplest dynamical sector (considered by many as a toy model) with global chiral symmetry (to be spontaneously broken) – self interacting scalar field, a doublet of SU(2)- IS NOW PROMOTED TO A REAL THING 3 Goldstone bosons + physical elementary scalar

5. GIARDINO ET AL.’13 3 IN SM THE HIGGS COUPLINGS TO A PAIR OF FERMIONS OR GAUGE BOSONS ARE IN PROPORTION TO THEIR MASSES VERY UNLIKELY TO REPRODUCE IT BY ACCIDENT IT REALLY APPEARS AS THE SM HIGGS PARTICLE!

6. IS THE SM A CONSISTENT THEORY UP TO THE PLANCK SCALE (LIKE e.g. QED)? YES! RENORMALISABLE NO LANDAU POLE UP TO Mp (ALMOST) STABLE VACUUM UP TO Mp THOSE CONCLUSIONS STRONGLY DEPEND ON AT LEAST AT THE ELECTROWEAK SCALE, THE SM IS A CORRECT EFFECTIVE THEORY OF ELECTROWEAK INTERACTIONS

7. THE HIGGS MASS HAPPENS TO BE WELL BELOW THE PERTURBATIVITY LIMIT AND AT THE EDGE OF THE VACUUM STABILITY BOUND (FOR THE TOP MASS AROUND 173 GeV) UP TO THE PLANCK SCALE

8. IS THE SM A CONSISTENT THEORY UP TO THE PLANCK SCALE? YES BUT…. ISNT IT INDEED JUST AN EFFECTIVE THEORY, AN APPROXIMATION TO A DEEPER ONE (SIMILARLY AS QED, ALTHOUGH CONSITENT UP TO Mp, IS ONLY LOW ENERGY APPROXIMATION TO SM)? BY THE WAY, RENORMALISABILITY IS A GREAT VIRTUE OF EFFECTIVE THEORIES

9. less than (3- 5) % deviations from the SM couplings VERY CHALLANGING: DEVIATIONS MAY BE OF THE ORDER OF THE PRESENT UNCERTAINITIES IN THE SM PREDICTIONS INDEED, IN SPITE OF NO HINT FOR NP AT THE LHC, DONT RUSH TO A TOO QUICK CONCLUSION ON THE VALIDITY OF THE SM TO PLANCK SCALE BECAUSE: HIGGS COUPLINGS VERSUS NEW SCALES: 8

10. NO MATTER HOW CHALLANGING IT MAY BE TO SEE BSM PHYSICS THAT WAY, PRECISION HIGGS (AND TOP) PHYSICS LOOKS NOW LIKE A MUST! (CLIC, ILC, FCC?) 9

11. EMPIRICAL EVIDENCE FOR BSM: DARK MATTER-- THIS IS NOW THE CRUCIAL PROBLEM IN PARTICLE PHYSICS (WITH A PARTICLE PHYSICS SOLUTION?) 11 IF THERMAL EQUILIBRUM IN THE EARLY UNIVERSE IS THE SOURCE OF THE DM RELIC ABUNDANCE, THEN THE VALUE IS THE MAJOR HINT FOR A LOW SCALE NEW PHYSICS ! + DIRECT DETECTION + LHC -> RELEVANT PARAMETR SPACE BEGINS TO BE TESTED WHY BSM, IN SPITE OF THE SUCCESS OF SM- CONT…

12. THE HIGGS PARTICLE WOULD BE THE FIRST EXAMPLE OF AN ELEMENTARY SCALAR PARTICLE! So far, Nature does not seem to like elementary scalars and the composite ones are never „unnaturally ” light (much lighter than the compositeness scale) unless they are (pseudo) Nambu- Goldstone bosons, like pions in QCD WHY BSM, IN SPITE OF THE SUCCESS OF SM- CONT… ANY SHORT DISTANCE PHYSICS THAT COUPLES TO THE HIGGS (RH NEUTRINO, GUT PARTICLES..) WOULD INTRODUCE QUADRATIC SENSITIVITY OF VEV TO THOSE SCALES NATURALNESS PROBLEM OF THE SM:

13. STRICTLY SPEAKING, IT IS NOT THE PROBLEM OF QUADRATIC DIVERGENCES IN THE SM: IF NO SCALES EXCEPT V=240 GEV AND IGNORING GRAVITY AS A PHYSICAL CUT-OFF, ONE MAY IGNORE THE PROBLEM (BECAUSE THE SM IS RENORMALISABLE)

14. IN ADDITION, Higgs potential in the SM: describes but does not explain dynamically the origin of the Fermi scale IF IT HAS A DYNAMICAL EXPLANATION, THE SM SHOULD BE EMBEDDED IN A DEEPER THEORY! OTHERWISE, ANTHROPIC PRINCIPLE HAS TO BE INVOKED? BUT WE NEED ONLY ONE SCALAR. WHAT IF MORE ARE DISCOVERED?

15. GIVEN THE APPARENT FINAL SUCCESS OF THE SM AND THE ABSENCE OF ANY EVIDENCE FOR NEW PARTICLES (SO FAR)— HAS THE CASE FOR BSM PHYSICS CLOSE TO THE ELECTROWEAK SCALE CHANGED? THE MOTIVATION REMAINS INTACT: DARK MATTER AND THE QUESTION ABOUT THE ORIGIN OF THE FERMI CONSTANT 10 HOPEFULLY, THE SOLUTION TO THE DM IS PART OF A COMPLETE BSM THEORY CLOSE TO THE WEAK SCALE BUT IT IS ALSO CONCEIVEABLE THAT IT IS NOT THE CASE

16. WITH THE ABOVE GUIDELINE, THERE ARE TWO MAIN DIRECTIONS: SUPERSYMMETRY COMPOSITE HIGGS MODELS (HIGGS DOUBLET AS A NAMBU- GOLDSTONE BOSON OF A NEW STRONG SECTOR WITH A SUFFICIENTLY BIG SPONTANEOUSLY BROKEN GLOBAL SYMMETRY E.G. SO(5)  SO(4) 14 BOTH CAN ACCOMMODATE 125 GeV MASS AND ALMOST SM-LIKE COUPLINGS

17. UNIQUE FEATURE: CANCELLATION OF QUADRATIC SENSITIVITY TO ARBITRARILY HIGH SCALES ………….. ………. + ……….…….~ 15 SUPERSYMMETRY (FERMION – BOSON CANCELLATIONS)

18. FOR THE STOP MASS 1 TeV, SO WE GET 1% FINETUNING IN THE HIGGS POTENTIAL

19. 16 FERMION – FERMION CANCELLATIONS! EXP. SIGNATURES: HEAVY FERMIONS, SPIN 1 VECTOR MESONS

20. COMPOSITE MODELS CAN ACCOMMODATE 125 GeV HIGGS BOSON BUT, IT’S A PHYSICAL PICTURE RATHER THAN A REAL MODEL A LOT OF ARBITRARINESS, NO EASY UV COMPLETION, ELECTROWEAK SECTOR LINKED TO NON-PERTURBATIVE PHYSICS ALL THAT CAN BE CONFRONTED WITH THE WELL KNOWN VIRTUES OF SUPERSYMMETRY 17

21. MORE RECENTLY, REVIVAL OF THE IDEA OF CLASSICALLY SCALE INVARIANT SM (BARDEEN-1995) AT TREE LEVEL; EWSB BY QUANTUM CORRECTIONS-COLEMAN&WEINBERG ONLY LOGARITHMIC QUANTUM CORRECTIONS; IGNORING GRAVITY AS A PHYSICAL CUT-OFF AND IN CONSEQUENCE IGNORING QUADRATIC DEPENDENCE ON Mp DIMENSIONAL TRANSMUTATION a LA QCD, EXCEPT THAT IN QCD THERE IS NO ELEMENTARY SCALAR…

22. CAN ONE ALSO GET DM AND NEUTRINO MASSES IN SUCH ONE SCALE MODEL? TUNING IN MANY DIMENSIONLESS COUPLING? THEORETICALLY NOT WELL FOUNDED BUT INTRIGUING, IF A REALISTIC MODELS CAN BE CONSTRUCTED…

23. TWO THEORIES THAT PREDICT THE HIGGS MASS IN A CERTAIN NARROW RANGE, AS A FUNCTION OF THE TOP MASS SM EXTRAPOLATED TO THE PLANCK MASS MINIMAL SUPERSYMMETRIC MODEL AS A FUNCTION OF THE TOP AND STOP MASS TAKE 1 TeV FOR STOPS TO KEEP THE HIGGS POTENTIAL REASONABLY „NATURAL”

26. NON OBSERVATION OF THE SUPERPARTNERS IS CONSISTENT WITH THE HIGGS MASS BUT AT THE SAME TIME IS PUTTING THE IDEA OF NATURALNESS UNDER CERTAIN PRESSURE HOWEVER SUSY SEARCHERS ARE STILL QUITE FRAGMENTARY HIDDEN NATURALNESS? ( STEALTH SUPERSYMMETRY)

27. Searches for top squarks nDedicated searches for both direct and indirect production of top squarks; no signs of them (yet): uBut still room left for naturalness: e.g. M(gluino)~1.5 TeV; m(stop)~300 GeV; m(LSP)~150 GeV nReally need more energy! Feb 03, 2014CERN Accelerator School27

28. SUMMARY THE HIGGS DISCOVERY MAKES THE SM LOOKING AS A CONSISTENT THEORY UP TO VERY HIGH ENERGIES THE EXPERIMENTAL EXPLORATION OF THE TeV SCALE IS STILL IN A VERY PRELIMINARY STAGE 25 BUT THE CASE FOR THE BSM PHYSICS REMAINS INTACT: DARK MATTER AND DYNAMICAL ORIGIN OF THE FERMI CONSTANT. MAY OR MAY NOT BE UNDERSTOOD IN ONE THEORETICAL FRAMEWORK? SUPERSYMMETRY REMAINS TO BE THE LEADING CANDIDATE CLASSICALLY SCALE INVARIANT SM (PLUS MINIMAL ADDITIONS)?

29. END