1. REVISITING THE GOD PARTICLE …… Bangabasi College, Kolkata
Partha Ghosh
Department of Physics
Bangabasi College, Kolkata

2. News Headlines 05.07.2012 Revisiting the God Particle
There is nothing as such God-ly in the Higgs…It is just a name given by the editor of a popular science book, replacing the author’s own “Goddamned Particle” by “God Particle”.
God has not been found or discovered, it is just a particle what physicists believed to be present but not sure whether it could be confirmed experimentally.
Experimentalists working at CERN, Geneva, Switzerland, had confirmed a particle of that kind to be present.
Revisiting the
God Particle
Partha Ghosh
Department of Physics
Bangabasi College
Kolkata

3. What are we made of? Revisiting the God Particle…
According to Ancient Indian Philosophy, by……
Earth, Water, Air, Fire & Sky…..
According to present day scientists, by…
Point fermionic particles like quarks & leptons
which interact via bosons…..
AND
According to more ambitious theoretical
physicists, by….
Strings vibrating in eleven dimensional
spacetime……
Revisiting the
God Particle…
Partha Ghosh
Department of Physics
Bangabasi College
Kolkata

4. The Picture Till date Revisiting the God Particle
Our very dear Standard Model of Particle Physics, has seemingly been saved from being totally discarded…..
Revisiting the
God Particle
Partha Ghosh
Department of Physics
Bangabasi College
Kolkata

5. What is so standard about the model ?
Because it explains almost everything about the UNIVERSE, visible to us, correct to present day experimental limits…
Because it provides information about the elementary particles that makes up the large scale structure of the universe as a whole….
Because particles here before not observed but predicted by it have been confirmed to be present finally….
Because the interactions that the particles undergo have wonderful theoretical explanations….
Revisiting the
God Particle
Partha Ghosh
Department of Physics
Bangabasi College
Kolkata

6. The 4 fundamental interactions of nature…
Gravitational
described by Einstein’s General Theory of Relativity
& otherwise
Quantum Mechanics describing….
Electromagnetic,
Strong nuclear
&
Weak Nuclear forces
Revisiting the
God Particle
Partha Ghosh
Department of Physics
Bangabasi College
Kolkata

7. Exchange is the magic…. Revisiting the God Particle
Just as the two skaters juggling on ice can move away from each other by throwing balls to each other, elementary particles can also repel and attract each other by exchanging particles known as gauge bosons……
Partha Ghosh
Department of Physics
Bangabasi College
Kolkata
The neutral Photon, The Coloured Gluons, The massive W and Z bosons, The undiscovered Graviton and also the Higgs…

8. HOW WAS THE BEGINNING ? Revisiting the God Particle
It is believed that our Universe had been generated from a an explosion known as BIG BANG and has been expanding since then.
All the forces were unified at that very beginning and eventually in 3 minutes, by spontaneous symmetry breaking, became as now…
Partha Ghosh
Department of Physics
Bangabasi College
Kolkata

9. BEING HEAVY OR LIGHT ? that’s a big deal…
Standard Model calculations prior to required elementary particles to be massless.
But that would be violating our day to day observations and put things to jeopardy.
Several physicists including Peter Higgs had proposed a new idea called Higgs mechanism by which some particles may acquire mass .
The Higgs field is prevalent everywhere in space and particles have to interact with it in order to be massive.
The Higgs Boson is the fundamental constituent of the field as photon is to light.
Revisiting the
God Particle
Partha Ghosh
Department of Physics
Bangabasi College
Kolkata

10. THE MECHANISM IS THAT WHAT MATTERS, AFTERALL..
Revisiting the
God Particle
A particle can be massive or massless accordingly as where it locates itself in the Mexican Hat shaped Higgs potential, and if it were a Boson, whether the interaction it gives rise to would be short or long ranged…..
Partha Ghosh
Department of Physics
Bangabasi College
Kolkata

11. AN INTERESTING FACT-BITE TO SHARE!
In a Kg Man, the weight of Higgs Boson present is estimated to be about 1 Kg;
Another 1 Kg is for electromagnetic interactions
and
Revisiting the
God Particle
The rest 98 Kg for the protons, neutrons and electrons interacting with the Higgs Field and thereby acquiring respective masses……
Partha Ghosh
Department of Physics
Bangabasi College
Kolkata

12. SO HOW HEAVY IS THE HIGGS ?
Standard Model Higgs mechanism predicts a certain range of masses for the Higgs particle.
Located in Giga electron Volt range, it requires tremendous energy to be formed.
Experimentalists working at Tevatron Collider, Fermilab, USA and also at CERN’s LEP had gradually narrowed down the range of mass of it.
Finally at the LHC, the ATLAS and CMS collaboration searched between GeV and finally revolutionized the world on 4th July with their joint announcement.
Revisiting the
God Particle
Partha Ghosh
Department of Physics
Bangabasi College
Kolkata

13. WHAT HAPPENED AT THE CERN -LHC?
Revisiting the
God Particle
Conditions similar to Big Bang were created by smashing protons, accelerated to extremely high energies, with each other. The debris was studied with a number of sensitive detectors and then the huge data was statistically interpreted to predict the results.
Partha Ghosh
Department of Physics
Bangabasi College
Kolkata

14. THE FAMOUS TWO PHOTON DECAY MODE
Revisiting the
God Particle
Partha Ghosh
Department of Physics
Bangabasi College
Kolkata
ATLAS & CMS HAVE CONFIRMED IT……TO OCCUR FROM A HIGGS-LIKE PARTICLE.

15. WHAT NEXT ? BEYOND THE STANDARD MODEL….
SUPERSYMMETRY?
With the observed Higgs mass, Standard Model is valid till the Planck scale of energy.
Beyond that, SUSY theories require a number of Higgs to exist, even charged ones.
SUSY, if confirmed in future, would open doors to understand our Universe even better.
About 96% of our universe is still not visible; Higgs may lead to further knowledge of the so called Dark Matter.
Basic notion of Matter – Antimatter asymmetry of the visible Universe needs to be solved.
The Hierarchy Problem and Cosmological constants needs to be revisited.
Revisiting the
God Particle
Partha Ghosh
Department of Physics
Bangabasi College
Kolkata

16. TO CONCLUDE…. Revisiting the God Particle
“ The scientist doesn't study nature because it is useful ; he studies it because he delights in it, and he delights in it because it is beautiful…….I mean that profounder beauty which comes from the harmonious order of the parts, and which a pure intelligence can grasp.” ………..Henry Poincare
Revisiting the
God Particle
SO….WE HAVE MILES TO GO AND LOT MORE TO KNOW BEFORE WE SLEEP…..
Partha Ghosh
Department of Physics
Bangabasi College
Kolkata
THANKS A LOT FOR BEARINNG WITH ME FOR SO LONG