View
2
Download
0
Category
Preview:
Citation preview
5/18/2012 1
Grand Unified theory, God Particle and the
Missing Universe
Presented by
Abraham A.
Christian College
Chengannur
5/18/2012 2
Warning What you will hear in this session may alter your perception of reality and the universe itself. Please stay awake.
However, just in case you sleep, don’t snore.
5/18/2012 3
Fundamental interactions of nature
1/32
5/18/2012 4
Mediating particle concept
2/32
5/18/2012 5
Fundamental interaction characteristics
3/32
5/18/2012 6
The Elementary world
4/32
Mesons (2 Quarks) Baryons (3 Quarks)
Leptons(Irresponsive to Strong forces)
Hadrons(Responsive to Strong forces)
Matter
5/18/2012 7
Just a few of them ! 5/32
5/18/2012 8
I can’t remember them all !! 6/32
"Young man, if I could remember the names of these
particles, I would have been a botanist !”
-Enrico Fermi to his student Lederman
(both Nobel laureates)
5/18/2012 9
The Leptons
7/32
5/18/2012 10
8/32
Q.Which is the most abundant Matter particle in the universe?
The neutrino
5/18/2012 11
So many of them ! 9/32
1014 neutrinos
per second from Sun
are zipping through you
n
Every cm2 of Earth surface is crossed every second by more than 10 billion (1010) neutrinos produced in the Sun
No worries!
Neutrinos do not harm us.
Our bodies are transparent to neutrinos.
5/18/2012 12
10/32
The puzzling neutrinos o Near zero mass oAlmost no interactions (only weak)
o Can cross light-years of material without being affected o Can travel from the most remote corners of the Universe bringing information from the origin of space and time
They do matter to us: If there were no neutrinos the sun would not shine!
5/18/2012 13
The Solar Neutrino mystery
11/32
R. Davis: Measuring the solar neutrino flux in a gold mine in South Dakota for 30 years (1969-1999)
…and observing only 1/4 of the expected flux!! Why?
5/18/2012 14
The mystery solved-Neutrino oscillations
nm
nt
A detector here
does sees only nm
A detector here
sees only n t
The neutrinos change from one kind to another through neutrino oscillations. Thus the expected reaction does not occur at the calculated rate.
11/40 11/40
12/32
5/18/2012 15
13/32
Discovery of neutrino oscillation in the Super-Kamiokande (1998)
o Half of the nm are lost! Oscillated to undetected nt
o Neutrons have negligible but non-zero mass
Koshiba (Super Kamiokande Spokesman) : 2002 Nobel Prize [shared with R.Davis]
5/18/2012 16
14/32
5/18/2012 17
15/32
Internal structure of Hadrons
o Uneven internal distribution of charge.
o Two or three intense charge regions. o Internal Quark structure inferred. o Quark + Anti-Quark structure for Mesons. o Three Quark structure for Baryons.
5/18/2012 18
16/32
Generations of Quarks
Generations of Quarks are progressively heavy and require greater energy for production
5/18/2012 19
17/32 Colors of Quarks
oDifferent colors of Quarks can co-exist even if they have the other quantum numbers same.
oBaryons with three colors of Quarks have no resultant color (in analogy with optics) . o Mesons also have no color due to color + anti-color addition.
5/18/2012 20
18/32
Quark structure of some Hadrons
Proton Neutron
Omega Hyperon
5/18/2012 21
19/32
Occurrence of Quarks
o Quarks have not been found in isolation. o Quark confinement prevents their separation.
oThe phenomenon follows from the theory of Quantum Chromo dynamics (QCD) o Forced Energetic separation of Quarks produce two new pairs of quarks.
5/18/2012 22
Quark confinement • There are no free quarks, quarks and anti-quarks are “confined” in colourless doublet (mesons) or triplets (baryons) by the exchange of gluons
The new quarks bound to the old quarks and form new mesons
Here, the gluon connection snaps, and other quark-antiquark pairs are created out of the energy released
Gluon hold quarks together as they move further apart
Z0
Decay
® S.Ward
20/32
5/18/2012 23
Fundamental interactions Once more
21/32
5/18/2012 24
Unification stage-1 Electroweak force
22/32
Glashow, Weinberg and Salam (GWS, 1961 – 1968 ) developed a theory that unifies the electromagnetic and weak forces into one electroweak force.
The Exchange particles are four Bosons generated
through symmetry breaking
oZ
oW+
oW-
oPhoton
5/18/2012 25
Unification stage-2 Standard Model success
23/32
o Electroweak + strong
o All matter constituents
o 6 quarks and 6 Leptons
o Structure of matter ~10-18 m
o Pioneers awarded 20 Nobel prizes.
5/18/2012 26
Unification stage-2 Standard Model constituents
24/32
5/18/2012 27
Unification stage-2 Higgs field & God Particle
25/32
oHiggs field exists every where
oThe field imparts mass to particles while breaking symmetry
oMass α Field interaction
oInteraction mediated by the Higgs Boson
Ho
5/18/2012 28
Unification stage-2 Search for the Higgs Boson
26/32
oThe energy of the particle is >> Tev/c2
oIt is hoped that the LHC will produce the God particle
5/18/2012 29
Unification stage-3 The Grand Unification
27/32
5/18/2012 30
Unification stage-3 The GUT symmetry
28/32
S’ =S+ (1/2)
5/18/2012 31
The Land Marks in unification
29/32
5/18/2012 32
The fate of the Universe
30/32
5/18/2012 33
Composition of the Universe
31/32
5/18/2012 34
The Missing Universe
32/32
Chart of the matter of the universe-In a way, this chart is an embarrassment for scientists. We are only able to account for 4% of the matter in the universe.
5/18/2012 35
THANK YOU
isureshabraham@gmail.com
Recommended