This presentation is about higgs boson, some elementary ideas of higgs particle, its properties, facts about LHC

1. HIGGS BOSON
Presented by
Abhijeet Das
M.Sc. (4th Semester)
ID- BS13MP0360 1

2. It is the branch of physics that studies the nature of the particle which are the constituents
of matter (particle with mass) and radiation ( massless particle).
e.g., Proton, Neutron, Photon
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3. It is a theory which deals with the description of the three fundamentals forces of nature
i.e., electromagnetic, weak and strong forces using gauge bosons. It is still unable to
explain the gravitational force.
The species of gauge bosons are W-, W+ and Z bosons and gluons and photons.
This model predicted the existence of higgs boson.
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Reference: Google Images

4. 1. Symmetries and forces: According to Standard Model the fundamental forces
arise from symmetry and are transmitted by particles called gauge bosons.
The weak force symmetry should cause its gauge bosons (W and Z boson) to have
zero mass but experiments show that the gauge bosons are very massive and short
ranged.
2. Higgs Mechanism: It is a mathematical model which was devised by 3 group
of physicist (Higgs, Englert and Brout, Guralnik, Hagen and Kibble)
almost at the same time to describe why and how gauge bosons could be massive in
spite of their symmetry.
They showed that the symmetry would be broken if an unusual type of field exist
throughout the space which would enable particles to have mass.
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5. 3. Higgs Field: According to Standard Model a field (Higgs field) is necessary to
exist throughout the space and should break the symmetry laws of electroweak
interaction.
The existence of this field triggers the Higgs mechanism causing the gauge bosons to
be massive.
4. Higgs Boson: The existence of the Higgs field could be confirmed if a
particle (Higgs Boson) associated with this field could be found.
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6. Peter Higgs Englert
Reference: Google Images 6

7. Brout Kibble, Hagen and Guralnik
(from right to left)
Reference: Google Images 7

8.  In particle physics, elementary particles give rise to the world around us.
 Physicists tries to explain the behaviour of these elementary particles and
their interaction using The Standard Model which believes to explain everything
other than gravity.
 Around 1960 all attempts to create a gauge invariant theory for two of the
four fundamental forces of nature failed at a point. They demand that either
particles with mass were massless or massless particles had to exist.
 In 1964 three group of researchers independent of each other showed that the
problem could be resolved if an unusual kind of field exist throughout the space
which would cause existing particles to acquire mass.
 The simplest way to find the existence of this field was to find a particle
which would give rise to that field.
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9. On 4th April 2012 morning the ATLAS and CMS detectors each observed a new particle
in the mass region of 126GeV . This particle is consistent with the Higgs boson as
predicted by the Standard Model.
Reference: Google Images
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1. It is a boson.
2. Mass = 125.09(+-)0.21(stat)(+-)0.11(syst)
3. Mean Lifetime = 1.56*10-22 sec
4. Electric Charge = 0
5. Color charge = 0
6. Spin = 0
7. Parity = positive

11.  Validating the standard model
 Explain symmetry breaking
 Explain how particles acquire mass
 Existence of a scalar field in the universe
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13.  It is the world’s largest and most powerful particle collider built by CERN from 1998 to
2008.
 It is built in collaboration with 10,000 scientists and engineers.
 It has a tunnel with 27km in circumference and as deep as 175m (574 ft) beneath the
Franco-Swiss border near Geneva Switzerland.
 Its synchrotron is made to collide two opposite particle beams of either proton at up to
4TeV or lead nuclei (574TeV per nucleus or 2.76 per nucleon) with energies increased to
around 6.5Tev (13TeV collision energy) in 2015.
 The data is anticipated to be produced at the rate of tens of petabytes per year which is
analyzed by a grid based computer network connecting 140 computer centers in 35 countries.
 It went live on 10th September 2008.
 There are 1,232 dipole magnets to keep the beam at circular path and 392 quadrapole
magnets to keep the beam focused.
 Approximately 96 tones of superfluid He-4 is needed to keep the magnets made of copper-
clad niobium-titanium at the operating temperature of 1.9K (-271.25°C) making it the largest
cryogenic facility in the world.
 The speed of the proton is 3 m/s slower than the speed of light.
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14. ATLAS (A toroidal LHC apparatus) and CMS (Compact MUON solenoid): They are
used for detecting things like new mass and extra dimensions
ALICE (A large ion collider experiment): It is built to study a fluid form of matter called
quark-gluon plasma that existed shortly after the big-bang.
LHCb (Large hadron collider beauty): It is built to study the anti-matter.
TOTEM (Total elastic and diffractive crossection measurement): It aims to measure
the total crossection, elastic scattering etc.
MoEDAL (Monopole and exotic detectors at the LHC): It aims to directly search for
magnetic monopole or dyon and other highly ionizing stable massive particles.
LHCf (Large Hadron Collider forward): It aims to study the particles in the forward
region of collision. It intends to study the energy of neutral pions which can explain the
origin of the ultra high energy cosmic rays.
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15. For now there are no technological applications of the Higgs boson.
When fundamental discoveries are made there application in the real world
takes times but when they do they have a big impact on the world.
e.g., “www” was created at CERN to share the results of experiments by
Sir Timothy John Tim Berners-Lee
CERN- Conseil European pour la Recherche Nucléaire
OR
European Organization for Nuclear Research
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