grand unified theory, god particle and the missing universe · grand unified theory, god particle...
TRANSCRIPT
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
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Mediating particle concept
2/32
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Fundamental interaction characteristics
3/32
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The Elementary world
4/32
Mesons (2 Quarks) Baryons (3 Quarks)
Leptons(Irresponsive to Strong forces)
Hadrons(Responsive to Strong forces)
Matter
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Just a few of them ! 5/32
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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)
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The Leptons
7/32
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8/32
Q.Which is the most abundant Matter particle in the universe?
The neutrino
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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.
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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
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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]
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14/32
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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.
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16/32
Generations of Quarks
Generations of Quarks are progressively heavy and require greater energy for production
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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.
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18/32
Quark structure of some Hadrons
Proton Neutron
Omega Hyperon
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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.
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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
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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
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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.
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Unification stage-2 Standard Model constituents
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Unification stage-2 Higgs field & God Particle
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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
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Unification stage-2 Search for the Higgs Boson
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oThe energy of the particle is >> Tev/c2
oIt is hoped that the LHC will produce the God particle
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Unification stage-3 The Grand Unification
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Unification stage-3 The GUT symmetry
28/32
S’ =S+ (1/2)
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The Land Marks in unification
29/32
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The fate of the Universe
30/32
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Composition of the Universe
31/32
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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.
