Tài liệu GUTS, TOES and stringy things: biology or highenergy physics? docx

Elements of particle physics in the curriculum• Particle physics in the curriculum should include instruction on the basic foundation of matter, introduction to the known fundamental for

GUTs, TOEs and stringy things:

biology or high-energy physics?

Subtitle: Ways to teach the fundamental

question, “What are we made of and what holds

us together?”

Why should we teach it and if so, when?

Gordon P RamseyLoyola University Chicago

gpr@hep.anl.gov

Subtitle: Ways to teach the fundamental

question, “What are we made of and what holds

us together?”

Why should we teach it and if so, when?

Gordon P RamseyLoyola University Chicago

gpr@hep.anl.gov

Why study particle physics?

• Addresses the fundamental philosophical

questions: What are we made of and what holds us together?

• Particle physics is fundamental to

understanding the basic structure of matter

• It encompasses the studies all of the known forces in nature using conservation laws

• It gives insight on how we investigate the

smallest known scales in physics

Why study particle physics?

• With the ongoing research at accelerators around the world, the LHC going online and planned

future accelerators (NLC & VLHC), it is

state-of-the-art research

• The unrelated benefits reaped from past study of nuclear and particle physics (nuclear medicine and accelerated particle treatments of cancer) are of interest to everyone

• Particle physics has strong connections to

cosmology and astrophysics, at the opposite scale

of physics It is therefore “all inclusive”

• Use as an introduction to the role of engineering

in science.

Why study particle physics?

• On the more advanced level, it is a culmination

of mechanics (Lagrangians & Hamiltonians),

E&M (accelerator physics; QED), statistical

physics (QCD field theory) and modern physics

undergraduates

phenomenology and experimentation

Elements of particle physics in the curriculum

• Particle physics in the curriculum should

include instruction on the basic foundation of matter, introduction to the known

fundamental forces, problems addressed by

each sub-area of particle physics and the

current experimental research to test the

models proposed by theorists

phenomenological aspects of the field

• The excitement of doing HEP as a physicist

should be emphasized

Fundamental questions to address

• What is the ultimate structure of matter? QCD, QED, EW, Standard Model, beyond SM

• What is the origin of mass? Higgs mechanism

• Why is gravity so weak?

– If X=fractional contribution of gravitational

binding energy to the proton’s rest mass:

Fundamental questions to address

• How does particle physics play a role in

astrophysics and cosmology?

• Can the known forces be explained in terms of

a unifying theory?

– Long time unification – air, water, earth and fire

⇔ gas, liquid, solid, plasma

– Unification of gravitational & inertial mass,

electricity & magnetism, E-W forces, the standard model (E-W + QCD) and GUTs and TOEs (all

inclusive)

Particle physics curriculum at various

levels of instruction: high school

• AP topics in modern physics as a prelude:

– Key experiments, nuclear physics, γ (photons)

• Particle adventure – fundamental particles &

interactions

• Quarknet activities

• Possible topics:

– nuclear structure: make the connection between

molecules, atoms and nuclei with fundamental

particles

– talk about relative scales of each in macroscopic

terms (p + –e - distance in H-atom is like basketball or soccer ball to 10 km landmark)

• AP topics in modern physics as a prelude:

– Key experiments, nuclear physics, γ (photons)

• Particle adventure – fundamental particles &

interactions

• Quarknet activities

• Possible topics:

– nuclear structure: make the connection between

molecules, atoms and nuclei with fundamental

particles

– talk about relative scales of each in macroscopic

terms (p + –e - distance in H-atom is like basketball or soccer ball to 10 km landmark)

Particle physics curriculum at various

levels of instruction: high school

– Application of basic physical laws (forces & conservation laws) to particle physics

– Overview of the scientific process (modeling, experimentation and their interplay)

– Elementary quark model and role of gluons– Overview of experimental facilities

Particle physics curriculum at various

levels of instruction: high school

• Tools for instruction in high school courses:

– Quarknet

– I2U2 (Interactions in Understanding the Universe – Simulated data from accelerators

– FNAL programs

– PAN (Physics of Atomic Nuclei)

– Cosmic ray e-Lab

– EPPOG – European PP outreach group

• See talks in session IE: Sun a.m., H-Crystal A

• Tools for instruction in high school courses:

– Quarknet

– I2U2 (Interactions in Understanding the Universe – Simulated data from accelerators

– FNAL programs

– PAN (Physics of Atomic Nuclei)

– Cosmic ray e-Lab

– EPPOG – European PP outreach group

• See talks in session IE: Sun a.m., H-Crystal A

The Standard Model

µ

up

down

u d

charm

strange

c s

top

bottomb t

Simple Quark Model

• Properties and interactions described by

• Properties of nucleons described by

• Highly successful model - neat and compact

• Developed in 1963, Gell-Mann & Zweig

Simple Quark Model (cont’d)

Properties not fully explained: mass & spin

A more comprehensive picture is needed:

Enter: The Standard Model!

u

u d

Quarks

Gluons

d

u s

Sea

Fermilab → 40 miles west of us: Batavia, IL

Currently one of the highest energy accelerators operating in the world.

Main Ring + Injector Ring

• Main Ring Radius: 1 Km (6.28 Km circum.)

CDF (Colliding Detector “Facility”)

Brookhaven National Laboratory

Inside RHIC

Inside the RHIC tunnel

Two tubes, 2.4-mile ring

RHIC superconducting magnet

Computer image magnetic field

STAR p+p, √s = 200 GeV STAR Au+Au, √s = 200 GeVNN

Look for hadron jets as signal of scattered partons:

Unfortunately, cannot observe colored particles

directly…

STAR

LHC (Large Hadron Collider) @ CERN

Particle physics curriculum at various levels of instruction: undergraduate

• First year Coverage (relativity, atomic & nuclear

physics, elements of particle adventure)

• Liberal arts course – overview for non-scientists

• Modern physics course topics; introduction should

be the Particle Adventure for the fundamentals (see texts for topics)

• The advanced course can take on two forms:

intermediate (pre-QM) and advanced (post-QM)

• First year Coverage (relativity, atomic & nuclear

physics, elements of particle adventure)

• Liberal arts course – overview for non-scientists

• Modern physics course topics; introduction should

be the Particle Adventure for the fundamentals (see texts for topics)

• The advanced course can take on two forms:

intermediate (pre-QM) and advanced (post-QM)

Particle physics curriculum at various levels of instruction: undergraduate

• Overview course for non-scientists:

“Particle Physics for (fill in your favorite humanities major)” – Basic structure of matter (atoms, nuclei, quarks…) – Basic physical laws (forces & conservation laws) – Overview of the scientific process (modeling,

experimentation and their interplay)

– Elementary quark model and role of gluons

– Stroll through the Particle Adventure

– Overview of experimental facilities

• Overview course for non-scientists:

“Particle Physics for (fill in your favorite humanities major)” – Basic structure of matter (atoms, nuclei, quarks…) – Basic physical laws (forces & conservation laws) – Overview of the scientific process (modeling,

experimentation and their interplay)

– Elementary quark model and role of gluons

– Stroll through the Particle Adventure

– Overview of experimental facilities

Particle physics curriculum:

undergraduate overview course

• Qualitative overview of present problems in

HEP and cosmology: fundamental structure of matter (nuclear and sub-nuclear, unification of forces, dark matter and energy, matter and

• Qualitative overview of present problems in

HEP and cosmology: fundamental structure of matter (nuclear and sub-nuclear, unification of forces, dark matter and energy, matter and

Particle physics curriculum:

undergraduate overview course

• Applications to include:

– Particle Beam cancer treatments

– Computer hardware and infrastructure (grids) – Magnet engineering & development

– Superconducting technology & cryogenics

– Free electron laser development

– Tunnel engineering & geological studies

– Training of highly technical workforce

– Etc… (fill in your favorite applications – WWW!)

• Applications to include:

– Particle Beam cancer treatments

– Computer hardware and infrastructure (grids) – Magnet engineering & development

– Superconducting technology & cryogenics

– Free electron laser development

– Tunnel engineering & geological studies

– Training of highly technical workforce

– Etc… (fill in your favorite applications – WWW!)

The Standard Model (SM)

• Nuclei are composed of quarks and gluons

• The SM connects the weak, EM and strong forces via QM and field theory

Unanswered questions in the SM

1 How do we include gravity into the SM? Gen Rel vs QM.

2 What gives particles mass? Higgs field and associated Boson interacts with

particles to give them mass.

3 Where is the “Higgs”? Lower limits of mass by FNAL & LEP are MLH > 115 GeV/c 2 –

LHC will probe higher masses

4 We are in a “matter universe” – where is the anti-matter? The LHCb & ALICE

experiments will simulate the early universe to study similar interactions that occurred

5 What is Dark Matter?

6 What is a quark-gluon plasma? BNL RHIC has collided heavy ions to create the q-g

plasma.

7 The LHC will probe these issues.

Particle physics in the undergraduate curriculum

• Two levels of courses for physics majors/minors: pre-QM (sophomore) and post-QM (senior)

• Essential topics to cover and references in both:

• Basic structure of matter

• Historical introduction (fundamental particles and forces, models in nuclear and particle physics –

shell, liquid drop; eightfold way and the quark

model, QED, QCD standard model)

• Symmetries (groups, spin, angular momenta);

• Essential topics to cover and references in both:

• Basic structure of matter

• Historical introduction (fundamental particles and forces, models in nuclear and particle physics –

shell, liquid drop; eightfold way and the quark

model, QED, QCD standard model)

• Symmetries (groups, spin, angular momenta);

symmetry variables (CPT)

• Bound states

• Dynamics: forces, interactions, decays and

conservation laws

Particle physics in the undergraduate

curriculum: pre-QM course

• Additional topics to include:

– Unification schemes

– Mathematical techniques: relativistic kinematics vectors); scattering

(4-– Accelerators & detectors (worldwide facilities)

– QED (Dirac equation, cross sections and scattering) – QCD (asymptotic freedom, quarks & gluons)

– Weak interactions (decays)

– Basic structure of unifying theories (GUTs, TOEs)

• Additional topics to include:

– Unification schemes

– Mathematical techniques: relativistic kinematics vectors); scattering

(4-– Accelerators & detectors (worldwide facilities)

– QED (Dirac equation, cross sections and scattering) – QCD (asymptotic freedom, quarks & gluons)

– Weak interactions (decays)

– Basic structure of unifying theories (GUTs, TOEs)

Particle physics in the undergraduate curriculum:

topics to include in a post-QM course

• QED (Dirac equation, photon, Feynman rules,

cross sections, lifetimes, scattering, scaling

• QCD (Feynman rules, asymptotic freedom, q-q,

G-G and q-G-G interactions, cross sections, scattering, scaling, spin)

• Weak interactions (decays, charged & neutral

weak interactions, EW unification)

• Gauge theories (more on grad level or for an

advanced class)

• Accelerators and detectors (facilities)

• Current theoretical and experimental research in these areas integrated throughout the topics

• Include unification, SUSY

• QED (Dirac equation, photon, Feynman rules,

cross sections, lifetimes, scattering, scaling

• QCD (Feynman rules, asymptotic freedom, q-q,

G-G and q-G-G interactions, cross sections, scattering, scaling, spin)

• Weak interactions (decays, charged & neutral

weak interactions, EW unification)

• Gauge theories (more on grad level or for an

advanced class)

• Accelerators and detectors (facilities)

• Current theoretical and experimental research in these areas integrated throughout the topics

• Include unification, SUSY

Particle physics in the undergraduate curriculum

• Mention TOEs, string theory, BNL (see texts

for topics)

• Hint as to how elements of HEP can be

included in all phases of the UG curriculum

Unified theories and strings are in the science news – how do we present these to

undergraduates – both majors and

non-majors?

• Mention TOEs, string theory, BNL (see texts

for topics)

• Hint as to how elements of HEP can be

included in all phases of the UG curriculum

Unified theories and strings are in the science news – how do we present these to

undergraduates – both majors and

non-majors?

µ

γ *

e p

Sea

Quantum Chromodynamics (Q C D)

Q C D = Theory of strong interaction

 Q C D more difficult than EM theory:

1 Gluons interact with each other (quarks)

2 Strong interaction 100 × stronger than EM

 Q C D: Very complicated processes make large contributions

EM: simplest processes have largest effects;

more complicated give higher precision

 Virtual q and g constantly created/destroyed - field theory

Interactions must be taken into account

Spin may be more important in Q C D than atomic physics

Particle physics in the graduate

curriculum

• Graduate topics include:

– Field theory

– Feynman rules & review of QED and QCD

– Standard model review

– Masses and Higgs mechanism

– CP violation

– Neutrino physics

– Experimental methods

– Phenomenology

– Unification schemes & present research topics

• Graduate topics include:

– Field theory

– Feynman rules & review of QED and QCD

– Standard model review

– Masses and Higgs mechanism

References: Web sites

• The Physics Teacher online:

http://scitation.aip.org/tpt/

• American Journal of Physics:

http://scitation.aip.org/ajp/

• Physics magazine online: http://physics.aps.org

• Particle adventure online at:

• Quarknet – research for HS & college students –

Web at: http://quarknet.fnal.gov

• Physics Central on the APS Web site:

• HEP news on the Web: http://physics.aps.org

References: Magazines & Journals

• “Power of Models in Physics – Nuclear Physics in the First Term of Introductory Physics”, D F Holcomb

• “A reappraisal of the mechanism of pion exchange and its implications for the teaching of particle physics”, P

Dunne, Physics Education, 37, 211, (2002)

• “Looking for consistency in the use of Feynman

diagrams” P Dunne, Phys Educ 36, 366, (2001)

• CERN Courier: Nov 2008, p 28 (Higgs and the LHC); Oct

2008, special issue on the LHC

• “A resource for particle physics teaching in schools”, KP

Zetle, Physics Education, 39, 107, (2003)

• APS News: Aug-Sep 2008, pp 1-3, 6

References: Books & Texts

• Introduction to Elementary Particles, David Griffiths, ©

1987, Harper Row, NY

• Quarks and Partons, F Halzen and Martin, © 19

• J Allday Quarks, Leptons and the Big Bang, Institute of Physics Publishing , Bristol , 1998.

• B R Martin and G Shaw, Particle Physics, J Wiley, 1995

• W S C Williams, Nuclear and Particle Physics, Oxford