Cosmic Rays, Neutrinos, Star Trek and the Universe

Slides:



Advertisements
Similar presentations
ORIGIN OF THE UNIVERSE P In the beginning, God created the heaven and the earth; and the earth was without form and void; and darkness was upon the face.
Advertisements

Cosmology The Origin and Future of the Universe Part 2 From the Big Bang to Today.
La teoria del big bang y la formacion del Universo.
Big Bang …..was actually very small and quiet. Atoms are mostly empty space.
Neutrino Physics Pedro Ochoa May 15th 2006.
“The Story of the neutrino” Does the missing matter matter? or.
Atmospheric Neutrino Anomaly
Neutrinos: No Mass, No Charge? No Problem! Prof. Kevin McFarland Experimental HEP Group University of Rochester.
Neutrino Mass By Ben Heimbigner.
Modern Physics LECTURE II.
A.Ereditato SS Elementarteilchenphysik Antonio Ereditato LHEP University of Bern Lesson on:Weak interaction (5) Exercises: beta decay, V-A structure.
UPRM Center Rafael Aramis López LEAD TEACHER. The Universe is made of Quarks and Leptons Everything from galaxies to mountains, to molecules is made from.
Dark Matter Masses of Galaxies Gravity and Light Black Holes What is Dark Matter?
Evolution of the Universe (continued)
Origin of the Universe Have you ever heard of a little thing called the “Big Bang?”
Sayfa 1 EP228 Particle Physics Department of Engineering Physics University of Gaziantep Dec 2014 Topic 5 Cosmic Connection Course web page
Structure of the Nucleus Every atom has a nucleus, a tiny but massive center.Every atom has a nucleus, a tiny but massive center. The nucleus is made up.
Hubble’s Law Our goals for learning What is Hubble’s Law?
The Dark Side of the Universe What is dark matter? Who cares?
The Elementary Particles. e−e− e−e− γγ u u γ d d The Basic Interactions of Particles g u, d W+W+ u d Z0Z0 ν ν Z0Z0 e−e− e−e− Z0Z0 e−e− νeνe W+W+ Electromagnetic.
The Big Bang Theory (Part II) The Evidence that Supports It Mike Stuckey Warren East High School.
The Birth of the Universe. Hubble Expansion and the Big Bang The fact that more distant galaxies are moving away from us more rapidly indicates that the.
Fisica Generale - Alan Giambattista, Betty McCarty Richardson Copyright © 2008 – The McGraw-Hill Companies s.r.l. 1 Chapter 30: Particle Physics Fundamental.
Cecilia Lunardini Institute for Nuclear Theory University of Washington
Chapter 17 The Beginning of Time. Running the Expansion Backward Temperature of the Universe from the Big Bang to the present (10 10 years ~ 3 x
Radioactive decay berçin cemre murat z. fundamental particles  electron  proton  neutron ?
J. Goodman – January 03 The Solution to the Solar Problem Jordan A. Goodman University of Maryland January 2003 Solar Neutrinos MSW Oscillations Super-K.
Neutrinos: What we’ve learned and what we still want to find out Jessica Clayton Astronomy Club November 10, 2008.
P630 Nuclear Astrophysics Charles Horowitz Charles Horowitz Fall 2002, Indiana University Fall 2002, Indiana University Course Web site:
Birth of Neutrino Astrophysics
Particle Physics Why do we build particle accelerators? The surface is flat Still flat Oh no its not Big balls cannot detect small bumps.
1 PHY100 PHY100 ― The Nature of the Physical World Lecture 17 More Particle Physics Arán García-Bellido.
PHY100 ― The Nature of the Physical World November 5th, 2008
Physics 12 Mr. Jean January 12th, 2012.
• (because) like charges repel
CHAPTER 14 Elementary Particles
PHL424: 4 fundamental forces in nature
Neutrino Oscillations and T2K
Muon Lab Theory Muons (standard model) Cosmic rays Life time
Chapter 22: The Birth of the Universe
Teacher notes This ordering activity could be used as a plenary or revision exercise on the lifecycle of small stars, and the difference between small.
Neutrinos and the Evolution
HCP: Particle Physics Module, Lecture 4
E = mc2 If you can’t explain it simply, you haven’t learned it well enough. Einstein.
Big Bang: timeline.
The Big Bang Theory.
Building ICECUBE A Neutrino Telescope at the South Pole
Building ICECUBE A Neutrino Telescope at the South Pole
Origins of The Universe
Maarten de Jong Nikhef & Leiden University
The Beginning of Time (Birth Of The Universe)
PHL424: 4 fundamental forces in nature
Contemporary science issues
Pauli´s new particle * nt nm ne e m t Beta-Decay Pa 234 b (electron)
The Big Bang Theory.
What’s the matter with antimatter?
Birth of a Theory 1.3 p Once a hyposthesis has been tested…and tested….and tested…It might be moved into the realm of being a theory.
The Universe A journey through time.
FAMILIAR FORCES Probably the most familiar force is the gravitational force. It does not only pull objects towards the centre of the Earth. The Earth is.
The Big Bang Theory.
Formation of the Universe
Neutrino Physics & Astrophysics : Overview
Absorption lines of a galaxy shift toward the blue end of the spectrum when it moves toward Earth. The lines shift to the red end of the spectrum when.
1930: Energy conservation violated in β-decay
Technician’s Notes Activity 10S Software Based 'Bubble chamber photographs'
Particle Physics Lesson 6
Origin of Universe - Big Bang
Sun enrico.
THE UNIVERSE Part 2:Cosmology.
Recombination t = 380 ky T = 4000 K
Presentation transcript:

Cosmic Rays, Neutrinos, Star Trek and the Universe Kevin McFarland University of Rochester

The Mysterious Link Between Particles and the Universe In science, you: ask questions figure out how to answer them spend a long time answering them, probably with many little false steps along the way learn enough to ask the next question Sure, it seems repetitive, but sometimes it leads to really interesting questions from very odd or obscure ones

A Brief History of the Universe In the beginning, the Universe was very small and very hot Why small? Well, if we look at other galaxies, we see they are ALL moving away from us? It is something we did? No. How do we know? Doppler. bread model tells us this is nothing special about the sun…

A Brief History of the Universe In the beginning, very small and very hot Why hot? When you let a gas expand, it cools… Remember that heat is energy When the Universe was about 400000 years old, it was so hot that atoms kept being torn apart and recombining a lot like in our vapor lamp! Then as the universe cools, that stops. But what happens to all this energy from the glowing Universe? bread model tells us this is nothing special about the sun…

Cosmic Microwave Background I’ve got to be joking right? Actually, it’s a very interesting subject with perhaps the worst name ever… This is EXACTLY where the energy went. As the Universe cooled, so did the light now it is very low energy light… so low it is in the microwave frequency

Discovering the Cosmic Microwave Background would you believe it was an accident? Penzias and Wilson (shown below) were trying to develop microwave communications for Bell Labs was too noisy! kept trying to scrub bird droppings off the receiver but not even Mr. Clean can remove stains from the Big Bang!

What does it look like? It’s pretty bland… important fact!

What does it look like? Doppler effect of earth (parts per thousand)

What does it look like? Residual fluctuations (parts per million). Picture of Universe 400000 years after Big Bang

Where Did Particles Come From in the Big Bang? They came from decays of particles produced from energy in the Big Bang. How do particles (matter) become energy or energy become matter?

What Particles are found in the Early Universe? let’s look at the particle “periodic table” it has up and down quarks which make protons and neutrons which bind with electrons to make atoms so what’s all the stuff to the right? My attitude has totally changed!

Yeah! What is that Stuff? there just appear to be three copies of all the matter that really matters… all that distinguishes the “generations” is their mass My attitude has totally changed! -- I.I. Rabi

Particles in the Universe In the beginning, very small and very hot Now remember mass is also energy (E=mc2) Very early in the Universe, it was so hot that the masses of the different generations didn’t matter Then as the universe cools, suddenly generational mass differences were a big deal, and the massive generations needed to shed their extra mass (energy) Physicists call this sort of thing symmetry breaking But how do particles shed that extra mass? bread model tells us this is nothing special about the sun…

Detecting Cosmic Rays and Neutrinos

So what are cosmic rays? Cosmic rays are believed to initiate with very high energy (relativistic) protons Acceleration mechanism is unknown Except for small component from solar flares, cosmic rays originate outside solar system Probably galactic (rates, energy)

What on earth happens? “Primary” cosmic rays interact in atmosphere Kinetic energy of cosmic ray creates a shower of matter and anti-matter particles

Cosmic Ray Showers Shower of matter & anti-matter particles Lots of heavy particles are produced. They decay to things that can reach the ground muons, electrons, neutrinos Muon horizontal flux is ~1/cm2/min Hmmm… sounds like early Universe particles…

How do we see this? Scintillator and photomultipliers works well for finding muons from cosmic rays! That’s what you used for your work!

How do we see this (cont’d) Meet the “Mother of all paddles” Built in summer 2004 by a group of HS students and teachers at U of R Lives above my office in attic Data available on the web…

What could we use these for? Study the effect of the atmosphere

More dramatic: ask if our solar system has an effect! Forbush decreases, GLEs

How to Find Subatomic Particles How do we see any fundamental particle? Electromagnetic interactions kick electrons away from atoms This is why radiation is a health hazard…

An Aside on Radiation and Biology I’ve learned everything I need to know on this subject from comic books… the reality is less dramatic, more awful, but quantifiable. often not worthy of panic.

How to Find Subatomic Particles How do we see any fundamental particle? Electromagnetic interactions kick electrons away from atoms This is why radiation is a health hazard… But remember that neutrinos don’t have electric charge. They only interact weakly.

How Weak is Weak? 53 light-years Weak is, in fact, way weak. A 3 MeV neutrino produced in fusion from the sun will travel through water, on average, before interacting. The 3 MeV positron (anti-matter electron) produced in the same fusion process will travel 3 cm, on average. Apparently to hold up that VISOR, Jordy LaForge has a neck that would put an NFL offensive guard to shame… To find neutrinos, you need a lot of neutrinos and a lot of detector! 53 light-years

Getting lost along the way… Muons have a tough road to get down to the surface where we can see them! Atmosphere slows electrons and muons Muons decay (half-life of 1.5 microseconds) Neutrinos… unaffected by both problems!

So How Should we Detect Neutrinos? Leave it to Star Trek to point the way! Apparently, according to several episodes, Lt. Jordy LaForge’s VISOR can actually detect “neutrino field emissions” and what do we do in science except emulate Star Trek? Sadly, however, there is a catch

Modern Neutrino Hunting Super-Kamiokande (Masatoshi Koshiba, UR PhD 1955, Nobel 2002)

What does a neutrino from the atmosphere look like? Muons or electrons produced in inverse b-decay are going near c This exceeds speed of light in water, so get Cerenkov light Cones of light (think a boat wake in 3-D) intersect wall of detector and give rings

Modern Neutrino Hunting The Sun, imaged in neutrinos, by Super-Kamiokande Existence of the sun confirmed by neutrinos! The Sun, optical image

Where are Neutrinos Found? In the sun If the sun shines by fusion, energy reaching earth in light and in neutrinos is similar 100 billion neutrinos per cm2 per second rain on us Supernova 1987A (150000 light years away) exploded, releasing 100 times the neutrinos the sun will emit in its whole lifetime we observed 11 neutrinos in detectors on earth!

Where are Neutrinos Found? Bananas? We each contain about 20mg of 40K which is unstable and undergoes β decay So each of us emits 7500 neutrinos/sec For the same reason, the radioactivity of the earth results in 10 million neutrinos per cm2 per second here

Where are Neutrinos Found? The early Universe Decays of heavy generations left a waste trail (decays) of 100/cm3 of each neutrino species They are (now) very cold and slow and hard to detect But if they have even a very small mass, they make up much of the weight of the Universe

Anti-matter? Every fundamental particle has an anti-matter partner When the meet, they annihilate into pure energy. Alternatively, energy can become matter plus anti-matter

So you might ask… The early Universe had a lot of energy. Where is the anti-matter in the Universe? Good question… how do we know it isn’t around today? look for annihilations. As far away as we can tell, today there aren’t big matter and anti-matter collisions

My Research Goal (with more than a little help from my friends) Prove or disprove the hypothesis: neutrinos cause the matter anti-matter asymmetry in the Universe! We are using accelerators to make neutrinos to study whether or not neutrino anti-neutrino differences seeded this as the Universe cooled…

What does it take? Megawatts of accelerated protons to produce neutrinos e.g., T2K beam: 0.8-4.0 MW 100-1000kTon detectors, hundreds of km from source 1MTon is a cube of water, 100 meters on a side Experiments with 107 neutrinos seen to precisely measure how they interact MINERvA at FNAL, led by Rochester ~2010 UNO neutrino detector concept ~2020 ~2008

Conclusions Neutrinos! They are everywhere, so we’d better learn to live with them! long-term goal is to demonstrate matter and anti-matter differences in neutrinos can this seed the same asymmetry in the Universe? The mystery continues…

Backup

β-Decay? You learned about this in chemistry? β-decay turns neutrons into protons, increasing the atomic number of an atom that sounds awfully anticlimactic… who cares? actually, you do. A lot. Fusion in the sun requires that a proton turn into a neutron. Inverse of β-decay! Without β-decay, we are stuck where the sun don’t shine…

β-Decay and the Universe Extra generations must have shed mass by decaying to light generations Why? Well, we don’t see the heavy ones today in the Universe! And the only way for that to happen is… β-Decay!! Just as neutrons could decay to protons by β-decay, so heavy generations decay to light. bread model tells us this is nothing special about the sun…

Neutrinos -or- What I do for a Living…

The Birth of the Neutrino Wolfgang Pauli

Translation, Please? 4th December 1930 Dear Radioactive Ladies and Gentlemen, As the bearer of these lines, to whom I graciously ask you to listen, will explain to you in more detail, how because of the ”wrong” statistics of the N and 6Li nuclei and the continuous beta spectrum, I have hit upon a desperate remedy to save the ”exchange theorem” of statistics and the law of conservation of energy. Namely, the possibility that there could exist in the nuclei electrically neutral particles, that I wish to call neutrons, which have spin and obey the exclusion principle and which further differ from light quanta in that they do not travel with the velocity of light. The mass of the neutrons should be of the same order of magnitude as the electron mass (and in any event not larger than 0.01 proton masses). The continuous beta spectrum would then become understandable by the assumption that in beta decay a neutron is emitted in addition to the electron such that the sum of the energies of the neutron and the electron is constant... From now on, every solution to the issue must be discussed. Thus, dear radioactive people, look and judge. Your humble servant, W. Pauli 4th December 1930 Dear Radioactive Ladies and Gentlemen, As the bearer of these lines, to whom I graciously ask you to listen, will explain to you in more detail, how because of the ”wrong” statistics of the N and 6Li nuclei and the continuous beta spectrum, I have hit upon a desperate remedy to save the ”exchange theorem” of statistics and the law of conservation of energy. Namely, the possibility that there could exist in the nuclei electrically neutral particles, that I wish to call neutrons, which have spin and obey the exclusion principle and which further differ from light quanta in that they do not travel with the velocity of light. The mass of the neutrons should be of the same order of magnitude as the electron mass (and in any event not larger than 0.01 proton masses). The continuous beta spectrum would then become understandable by the assumption that in beta decay a neutron is emitted in addition to the electron such that the sum of the energies of the neutron and the electron is constant... From now on, every solution to the issue must be discussed. Thus, dear radioactive people, look and judge. Your humble servant, W. Pauli 4th December 1930 Dear Radioactive Ladies and Gentlemen, As the bearer of these lines, to whom I graciously ask you to listen, will explain to you in more detail, how because of the ”wrong” statistics of the N and 6Li nuclei and the continuous beta spectrum, I have hit upon a desperate remedy to save the ”exchange theorem” of statistics and the law of conservation of energy. Namely, the possibility that there could exist in the nuclei electrically neutral particles, that I wish to call neutrons, which have spin and obey the exclusion principle and which further differ from light quanta in that they do not travel with the velocity of light. The mass of the neutrons should be of the same order of magnitude as the electron mass (and in any event not larger than 0.01 proton masses). The continuous beta spectrum would then become understandable by the assumption that in beta decay a neutron is emitted in addition to the electron such that the sum of the energies of the neutron and the electron is constant... From now on, every solution to the issue must be discussed. Thus, dear radioactive people, look and judge. Unfortunately I will not be able to appear in Tübingen personally, because I am indispensable here due to a ball which will take place in Zürich during the night from December 6 to 7…. Your humble servant, W. Pauli

Translation, Please? To save the law of conservation of energy? If the above picture is complete, conservation of energy says β has one energy but we observe this instead Pauli suggests “neutron” takes away energy! β-decay The Energy of the “β”

The Story so Far Neutrinos are essential for β-Decay to occur (Pauli’s idea) β-Decay: makes the sun shine allows the cold Universe to be made of what we see today So although we are not made of neutrinos, we wouldn’t be here without them! Wow… maybe someone should study neutrinos…

ns… what are they good for? Neutrinos only feel the weak force a great way to study the weak force! or applications of weak forces (i.e., the sun) Is there just one weak interaction? one weak interaction (b decay, np+e-+ν) connects electrons and neutrinos but wait… there’s more. Another weak force discovered with ns! n Gargamelle, event from neutral weak force

What about this other weak force? It turns out that this weak force was the “prediction” of a theory that unified the electromagnetic and weak forces (Glashow, Salam, Weinberg, Nobel 1979) We still don’t know how to add the strong force and gravity to this picture “unification” still drives much of particle physics

A confusing aside… (made in Rochester) The basics of this neutral force are as expected however… … concluded the neutral weak force is a tiny bit too weak NuTeV Experiment (Profs. Bodek & McFarland at Rochester) Studied 1.7M neutrino and 0.35M anti-neutrino interactions

Discovery of the Neutrino Reines and Cowan (1955) Nobel Prize 1995 1 ton detector Neutrinos from a nuclear reactor

Modern Neutrino Hunting Radiochemical Detector Ray Davis (Nobel prize, 2002) ν+np+e- (stimulated β-decay) Use this to produce an unstable isotope, ν+37Cl37Ar+e- , which has 35 day half-life Put 615 tons of Perchloroethylene in a mine expect one 37Ar atom every 17 hours.

Modern Neutrino Hunting Ran from 1969-1998 Confirmed that sun shines from fusion But found 1/3 of ν !

Neutrino Flavor Remember that neutrinos were discovered by the appearance of the positron is no accident! it turns there are three neutrinos, each associated with a particular flavor OK… so here’s a question…

Would the real neutrino please stand up? Are these neutrinos “of definite flavor” the “real neutrinos” i.e., is a neutrino flavor eigenstate in an eigenstate of the neutrino mass matrix Or are we looking at neutrino puree? And of course, “why does anyone care?”

Neutrino Flavor Mixing What if neutrinos mixed? “normal modes” not a or b but a mix We have learned this phenomenology! This is called “neutrino flavor oscillation” a→b→a

The Role of Neutrino Mass There is an important condition for oscillation… … the masses of the different mass eigenstates must be distinct!

Summary of Neutrino Oscillations If neutrinos mass states mix to form flavors and the masses are different… This would explain the disappearing solar ns! since only electron flavor neutrinos make the detection reaction, ν+n→p+e-, occur

Schoedinger-ology… So each neutrino wavefunction has a time-varying phase in its rest frame Now, imagine you produce a neutrino of definite momentum but is a mixture of two masses, m1, m2 so pick up a phase difference in lab frame

Schoedinger-ology (cont’d) Phase difference Phase difference leads to interference effect, just like with sound waves Analog of “volume disappearing” in beats is original neutrino flavor disappearing

More Neutrino Flavor Changes Pions decay to make a muon flavored neutrino Muons decay to make one muon and one electron flavored each A very robust prediction

Atmospheric Neutrino Oscillations Muon like neutrinos going through earth “disappear” probably change to tau neutrinos

Future Neutrino Hunting New Ideas afoot Produce neutrinos at accelerators, send them long distances to massive detectors Goal: study differences between neutrinos and anti-neutrinos

Why Neutrinos and Anti-Neutrinos? Every fundamental particle has an anti-matter partner When the meet, they annihilate into pure energy. Alternatively, energy can become matter plus anti-matter

So you might ask… The early Universe had a lot of energy. Where is the anti-matter in the Universe? Good question… how do we know it isn’t around today? look for annihilations. As far away as we can tell, today there aren’t big matter and anti-matter collisions

neutrinos cause the matter anti-matter asymmetry in the Universe! Our New Goal Prove or disprove the hypothesis: neutrinos cause the matter anti-matter asymmetry in the Universe! We are using accelerators to make neutrinos to study whether or not neutrino anti-neutrino differences seeded this as the Universe cooled…