searching for a higgs boson & faster than light neutrinos
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Searching for a Higgs Boson & Faster Than Light Neutrinos. Mike Cooke & Dave Schmitz Fermilab. Inside an Atom. The Standard Model. Explains 3 of 4 forces: Electromagnetism ( γ ) Weak force (W & Z) Strong force (g) Not gravity! - PowerPoint PPT PresentationTRANSCRIPT
Dave Schmitz & Mike Cooke, Fermilab 1
Searching for a Higgs Boson&
Faster Than Light Neutrinos
Mike Cooke & Dave SchmitzFermilab
January 12, 2012
Dave Schmitz & Mike Cooke, Fermilab 2
Inside an Atom
January 12, 2012
Dave Schmitz & Mike Cooke, Fermilab 3
The Standard Model
• Explains 3 of 4forces:– Electromagnetism (γ)– Weak force (W & Z)– Strong force (g)– Not gravity!
• The matter you are familiar with ismade from the 3 circled particles
January 12, 2012
Dave Schmitz & Mike Cooke, Fermilab 4
The Higgs Boson
• Original problem: Standard Model particles are massless?!
• In 1964, Peter Higgs (and others!) invented a way toadd mass to SM particles– Must add one extra particle,
the “Higgs boson”• Current problem:
We haven’t seen it!January 12, 2012
Dave Schmitz & Mike Cooke, Fermilab 5
Making a Higgs Boson• We create new
matter using: E=mc2
p p_
Fermilab Tevatron
CERN Large Hadron Collider
January 12, 2012
Dave Schmitz & Mike Cooke, Fermilab 6
Looking for the Higgs Boson
• Fermilab’s Tevatron just finished a 10 year run:Proton-antiproton collisions: 634,000,000,000,000Higgs bosons potentially made: 11,000
• Hard to separatefrom backgroundthat looks verysimilar
January 12, 2012
Dave Schmitz & Mike Cooke, Fermilab 7
How Can We Find the Higgs?• Look everywhere!
January 12, 2012
Dave Schmitz & Mike Cooke, Fermilab 8
How Can We Find the Higgs?• Use all of the information we have!– Create a special variable that answers the question:
Does this event look like a Higgs or the background?
January 12, 2012
Dave Schmitz & Mike Cooke, Fermilab 9
Latest Results• LHC sees some extra events, but not enough to
claim they see a Higgs boson
January 12, 2012
Dave Schmitz & Mike Cooke, Fermilab 10
Expect Excitement in 2012!
• Tevatron (CDF & D0) will share final results!• LHC should have enough data to exclude a
Higgs if it doesn’t exist or observe it if it does!– Finding it means we have observed all SM
particles & we’ll begin to study the Higgs in detail– No Higgs means the LHC might make huge
discoveries over the next few years, since something must give particles mass!
January 12, 2012
Dave Schmitz & Mike Cooke, Fermilab 11
The Standard Model
January 12, 2012
Neutrinos
Dave Schmitz & Mike Cooke, Fermilab 12January 12, 2012
Fermi National Accelerator Laboratoryproton beams neutrino beams
Dave Schmitz & Mike Cooke, Fermilab 13January 12, 2012
protons neutrons electrons
It was once thought the entire Universe was made of these three particles?
NOT EVEN CLOSE!!In fact, we now know that for
every proton, neutron or electron, the Universe contains
A BILLION neutrinos!* *Not to mention dark matter and dark energy
Dave Schmitz & Mike Cooke, Fermilab 14January 12, 2012
In every cubic foot of space in the Universe,there are 10,000,000 neutrinos which were
created in the Big Bang and are still zooming around!
10,000,000
neutrinos
“Relic” Neutrinos
Dave Schmitz & Mike Cooke, Fermilab 15January 12, 2012
Whenever a star explodes as a Supernova, the most powerful explosions in the Universe, 99% of the energy is carried off by neutrinos!
Supernova 1994D
Dave Schmitz & Mike Cooke, Fermilab 16January 12, 2012
In fact, every star is an incredible neutrino factory throughout its lifetime,
including our star, the Sun.
Dave Schmitz & Mike Cooke, Fermilab 17January 12, 2012
Working on my neutrino
tan
2 sec. 3,400,000,000,0004 sec. 6,800,000,000,0006 sec. 10,200,000,000,0008 sec. 13,600,000,000,00010 sec. 17,000,000,000,000
2in x 2in square
93 million miles
8 minutes
0 sec. 0How many neutrinos in 10 seconds?
Dave Schmitz & Mike Cooke, Fermilab 18January 12, 2012
You don’t have to look to the cosmos to find neutrinos. For example:
A banana emits about 1 million neutrinos/day from decays of the small number of naturally occurring radioactive potassium atoms they
contain!
Dave Schmitz & Mike Cooke, Fermilab 19January 12, 2012
energetic protons delivered
by the accelerator
impinge upon a fixed metal target
creates short-livedcharged particles quickly decay
into neutrinos
which are focused forward by a strong magnetic field
nm
nm
nm
nm
nm
nm
Turns out that you can use an intense beam of protons
to create an intense beam of neutrinos
Dave Schmitz & Mike Cooke, Fermilab 20January 12, 2012
University of Chicago HEP Seminar – January 31, 2011
350 ft
170 ft~ 1 mile
protons from accelerator
target
1/3 mile decay pipe
neutrino detectors
NuMI Beam Line
Dave Schmitz & Mike Cooke, Fermilab 21January 12, 2012
Where are all those neutrinos headed?
And they make the journey
from Fermilab to northern
Minnesota in 1/400th of a
second!
456 miles
6 miles
5,400 tons, 2,300 ft
MINOS
Dave Schmitz & Mike Cooke, Fermilab 22January 12, 2012
The OPERA Experiment
A very similar setup to the Fermilab neutrino
beam They installed some additional
state-of-the-art devices for doing precise timing measurements at
CERN and in Italy
450 miles
Dave Schmitz & Mike Cooke, Fermilab 23January 12, 2012
The OPERA Neutrino Velocity Measurement
~1012 protons
In these beams, trillions of protons hit the target together spread over about 10 microseconds and you don’t know which proton made the neutrino you observed in your detector. So, how can you measure a 60 nanosecond difference?
Dave Schmitz & Mike Cooke, Fermilab 24January 12, 2012
These proton “bunches” hit the target twice every 6 seconds for years and
years…… so, many millions of times
About 15,000 of those “bunches” made a neutrino that was seen in the OPERA
detector The red line is the average pulse shape of the 1012
protons that hit the target together every 6 seconds
The black points are the measured time of the neutrino interactions – (speed of light)*(distance from CERN to
OPERA)
The remaining difference of 1043.4 nanoseconds
is mostly offsets caused by electronics(1 ft. of cable ≈ 1 ns)
The OPERA Neutrino Velocity Measurement
Dave Schmitz & Mike Cooke, Fermilab 25January 12, 2012
The OPERA Neutrino Velocity Measurement
Critical to carefully map out all the timing offsets caused
by the various electronics and the detector at both
CERN and the OPERA detector
But how much exactly?What they find is 985.6 ns1043.4 ns – 985.6 ns = (57.8 ± 7.8 ± 8.3)
ns
Dave Schmitz & Mike Cooke, Fermilab 26January 12, 2012
The OPERA Neutrino Velocity Measurement
Speed of light, c = 299,792 km/s
Speed of neutrino (OPERA) = 299,800 km/s
vneutrino = c × 1.00002
Dave Schmitz & Mike Cooke, Fermilab 27January 12, 2012
What Would Einstein Say?
If confirmed, it is impossible to overstate the importance of the finding.
The impacts on our understanding of the Universe could be immense.
It is obviously critical to confirm such challenging and important measurements by multiple groups in multiple ways.
As a first step, Fermilab is currently upgrading our time measurement systems at our neutrino beam to repeat the OPERA
experiment.
Dave Schmitz & Mike Cooke, Fermilab 28January 12, 2012
extras
Dave Schmitz & Mike Cooke, Fermilab 29January 12, 2012
nmnmnmnmnm
nmnm nm
nmntnmnmnm
ntnt
nm
nm
ntntntntnt
ntnt
nt
nm
nmnmntnmnm
nmnm
nt
nt
nmnmnmnmnm
nmnm
nm
nm
Distance
And look for them to oscillate
But you need a LOT of neutrinosbecause of how feebly they
interact
Dave Schmitz & Mike Cooke, Fermilab 30January 12, 2012
This could be possible if:
The ne, nm and nt are not the only way of
looking at the neutrinos
butThere are neutrino
states that mix together to makeup
ne, nm and nt and these neutrinos
have different masses
n1
n1
n2
n2
n3
n3
ne nm
nt
Dave Schmitz & Mike Cooke, Fermilab 31January 12, 2012
wave 1
wave 2
wave 1 + wave 2
+
time (distance)
neutrino oscillations
www.scienceclarified.com
Quantum mechanicsparticle wave
mass determines frequency
If neutrinos (n e,n m,n t) are actually mixtures of multiple
waves with different frequencies (different
masses)…They can interfere like any waves and change the neutrino’s flavor!
401 Hz
400 Hz
401 Hz + 400 Hz
Dave Schmitz & Mike Cooke, Fermilab 32
t
January 12, 2012
nm
m m
nm
m
nt
nm
Dave Schmitz & Mike Cooke, Fermilab 33January 12, 2012
So what might they tell us?Neutrinos are very very very
light
Why?
How is it that we exist, anyway?