Symmetry breaking: Pion as a Nambu-Goldstone boson
|
|
- Harriet Sharyl Powell
- 5 years ago
- Views:
Transcription
1 Symmetry breaking: Pion as a Nambu-Goldstone boson Stefan Kölling Universität Bonn Seminar zur theoretischen Teilchenphysik,
2 Structure 1 General theory of sponatneous symmetry breaking What it is Spontaneous breaking of a global continuous symmetry (classical) Spontaneous breaking of a global continuous symmetry (QFT) Quantum fluctuations 2 Pion as a Nambu-Goldstone Boson Weak decays Pion as a Nambu-Goldstone boson 3 Summary
3 What it is A symmetry is said to be spontaneously broken, if the Lagrangian exhibits a symmetry but the ground state/vacuum does not have this symmetry.
4 What it is A symmetry is said to be spontaneously broken, if the Lagrangian exhibits a symmetry but the ground state/vacuum does not have this symmetry. Goldstone-theorem If the Lagrangian is invariant under a continuous global symmetry operation g G and the vacuum is invariant under a subgroup H G, then there exist n(g/h)=n(g)-n(h) massless spinless particles. With n(g) the number of generators of the group G.
5 Spontaneous breaking of a global continuous symmetry (classical) L(Φ i, Φ i ) = 1 2 ( µφ i ) 2 V (Φ i ) with V (Φ i )invariant under a global continous symmetry group G i.e. V (Φ i ) = V (ρ(g)φ i ) with g G Φ i Φ, i = ρ(g)φ i Φ i + δφ i = Φ i + iɛ a T a Φ i
6 Spontaneous breaking of a global continuous symmetry (classical) L(Φ i, Φ i ) = 1 2 ( µφ i ) 2 V (Φ i ) with V (Φ i )invariant under a global continous symmetry group G i.e. V (Φ i ) = V (ρ(g)φ i ) with g G Φ i Φ, i = ρ(g)φ i Φ i + δφ i = Φ i + iɛ a T a Φ i We demand that the vacuum has a minimal energy minimize V Φ i,min =< 0 Φ i 0 >= const. χ i := Φ i Φ i,min V (Φ i ) = V (Φ i,min ) + V (Φ i,min )χ i V χ i χ j +... Φ i 2 Φ i Φ j
7 Spontaneous breaking of a global continuous symmetry (classical) V (Φ i,min ) is a minimum, therefore V Φ i (Φ i,min ) = 0 2 V Φ i Φ j : = M 2 ij is semi-positive definite
8 Spontaneous breaking of a global continuous symmetry (classical) V (Φ i,min ) is a minimum, therefore V Φ i (Φ i,min ) = 0 2 V Φ i Φ j : = M 2 ij is semi-positive definite Now use the symmetry: V (Φ i,min ) = V (ρ(g)φ i,min ) = V (Φ i,min ) M2 ij(δφ i,min )(δφ j,min ) 0 = M 2 ijδφ j,min 0 = M 2 ijt a Φ j,min i i
9 Spontaneous breaking of a global continuous symmetry (classical) important result 0 = M 2 ij T a Φ j,min i
10 Spontaneous breaking of a global continuous symmetry (classical) important result 0 = M 2 ij T a Φ j,min i 1 T a H G with T a Φ j,min = 0 Every generator of H leaves the vacuum invariant.
11 Spontaneous breaking of a global continuous symmetry (classical) important result 0 = M 2 ij T a Φ j,min i 1 2 T a H G with T a Φ j,min = 0 Every generator of H leaves the vacuum invariant. T a / H T a Φ j,min 0 T a Φ j,min is an eigenstate of M 2 with 0 eigenvalue T a Φ j,min is a Nambu-Goldstone boson The number of Nambu-Goldstone bosons is n(g)-n(h)=n(g/h).
12 Pictures L = 1 2 ( µφ) µ2 φ 2 λ 4! φ4 with φ min = φ = φ min + σ 6 λ µ2 L = 1 2 ( µσ) (2µ2 )σ 2 λ 4! σ4 λ 6 µσ3
13 Pictures L = 1 2 ( µφ) µ2 φ 2 λ 4! φ4 with φ min = φ = φ min + σ 6 λ µ2 L = 1 2 ( µσ) (2µ2 )σ 2 λ 4! σ4 λ 6 µσ3 Massive modes correspond to fluctuations in radial direction. Massless modes correspond to fluctuations in angular direction.
14 Spontaneous breaking of a global continuous symmetry (QFT) In QFT every continuous symmetry implies the existence of a conserved current J µ (x): µ J µ (x) = 0 Q = d D xj 0 ( x, t) is conserved, i.e. [H, Q] = 0
15 Spontaneous breaking of a global continuous symmetry (QFT) In QFT every continuous symmetry implies the existence of a conserved current J µ (x): µ J µ (x) = 0 Q = d D xj 0 ( x, t) is conserved, i.e. [H, Q] = 0 Q 0 > =0, for every energy-eigenstate Φ >= Φ 0 > define Φ > := e iθq Φe iθq 0 > H Φ > = He iθq Φe iθq 0 >= He iθq Φ 0 > = e iθq HΦ 0 >= e iθq EΦ 0 >= E Φ > Energy spectrum is organized in multiplets of degenerate states.
16 Spontaneous breaking of a global continuous symmetry (QFT) Q 0 > 0 Problem, Q is not defined < 0 Q 2 (t) 0 > = d D x < 0 J 0 ( x, t)q(t) 0 > = d D x < 0 e ip x J 0 ( 0, 0)e ip x Q(t) 0 > = d D x < 0 J 0 ( 0, t)q(t) 0 >
17 Spontaneous breaking of a global continuous symmetry (QFT) Q 0 > 0 Problem, Q is not defined < 0 Q 2 (t) 0 > = d D x < 0 J 0 ( x, t)q(t) 0 > = d D x < 0 e ip x J 0 ( 0, 0)e ip x Q(t) 0 > = d D x < 0 J 0 ( 0, t)q(t) 0 > But the commutator with Q may be well defined. Current conservation implies: 0 = d D x[ µ J µ ( x, t), Φ(0)] = 0 d D [J 0 ( x, t), Φ(0)] + d S [ J( x, t), Φ(0)]
18 Spontaneous breaking of a global continuous symmetry (QFT) d [Q(t), Φ(0)] = 0 dt The symmetry is broken, if there is an operator Φ s.t.: < 0 [Q(t), Φ(0)] 0 >= η 0
19 Spontaneous breaking of a global continuous symmetry (QFT) d [Q(t), Φ(0)] = 0 dt The symmetry is broken, if there is an operator Φ s.t.: < 0 [Q(t), Φ(0)] 0 >= η 0 then: η = n d D x{< 0 J 0 (x) n > < n Φ(0) 0 > < 0 Φ(0) n >< n J 0 (x) 0 >} = n (2π) D δ D ( p n ){< 0 J 0 (0) n > < n Φ(0) 0 > e ient < 0 Φ(0) n >< n J 0 (0) 0 > e ient }
20 Since this is time independent, there has to be a state with: Nambu-Goldstone Boson E n = 0 for p n = 0 m n = 0 < n Φ(0) 0 > 0 < 0 J 0 (0) n > 0
21 Since this is time independent, there has to be a state with: Nambu-Goldstone Boson E n = 0 for p n = 0 m n = 0 < n Φ(0) 0 > 0 < 0 J 0 (0) n > 0 So the Nambu-Goldstone boson has to carry all the quantum numbers of the conserved current. In general there will be n(g) currents J a µ. Of these n(h) generate the symmetry group of vacuum. So again there are n(g/h)=n(g)-n(h) Nambu-Goldstone bosons.
22 Quantum fluctuations Can the massless fields wander away from their ground state? Calculate mean square fluctuation: < b(0) 2 > = 1 Dbe (is[b]) b(0)b(0) Z 1 = lim Dse is(b) b(x)b(0) x 0 Z d d k e ik x = lim x 0 (2π) d k 2 The UV devergencies can be regulated by a cutoff. But for d 2 there is an IR divergence.
23 Quantum fluctuations Can the massless fields wander away from their ground state? Calculate mean square fluctuation: < b(0) 2 > = 1 Dbe (is[b]) b(0)b(0) Z 1 = lim Dse is(b) b(x)b(0) x 0 Z d d k e ik x = lim x 0 (2π) d k 2 The UV devergencies can be regulated by a cutoff. But for d 2 there is an IR divergence. Coleman-Mermin-Wagner theorem Spontaneous symmetry breaking is impossible in d 2.
24 How do pions enter the game? We want to calculate dacay rates of semileptonic decays like: Use an effective Lagrangian n p + e + ν π π 0 + e + ν L = G[ēγ µ (1 γ 5 )ν](j µ J µ5 ) Where J µ and J µ5 are hadronic currents which include strong interaction effects. We have to calculate < p J µ (x) J µ5 (x) n > or < 0 J µ (0) J µ5 (0) π >
25 Nucleon β-decay < p(k ) J µ5 (x) n(k) > =< k e ip x J µ5 (0)e ip x k > =< k J µ5 (0) k > e i(k k) x Use Lorentz invariance to simplify < k J µ5 (0) k > with q := k k < k J µ5 (0) k > = ū p (k )[ iγ µ γ 5 F (q 2 ) + q µ γ 5 G(q 2 ) + (k µ + k µ )γ 5 F 2(q 2 ) + i[γ µ, γ ν ]γ 5 q ν F 3(q 2 )]u n (k)
26 Nucleon β-decay < p(k ) J µ5 (x) n(k) > =< k e ip x J µ5 (0)e ip x k > =< k J µ5 (0) k > e i(k k) x Use Lorentz invariance to simplify < k J µ5 (0) k > with q := k k < k J µ5 (0) k > = ū p (k )[ iγ µ γ 5 F (q 2 ) + q µ γ 5 G(q 2 ) + (k µ + k µ )γ 5 F 2(q 2 ) + i[γ µ, γ ν ]γ 5 q ν F 3(q 2 )]u n (k) And use the Gordan-Identity: ū p (k )[i 1 2 [γ µ, γ ν ]γ 5 q ν ]u n (k) = ū p (k )[i(k µ + k µ )γ 5 + (m p m n )γ µ γ 5 ]ū n (k)
27 Nucleon β-decay So if we define: F 3 (q 2 ) = F 3(q 2 ) + 1 2i F 2(q 2 ) F(q 2 ) = F (q 2 ) (m p m n )F 2(q 2 )
28 Nucleon β-decay So if we define: F 3 (q 2 ) = F 3(q 2 ) + 1 2i F 2(q 2 ) F(q 2 ) = F (q 2 ) (m p m n )F 2(q 2 ) we obtain: Decomposition of < k J µ5 (0) k > into Form factors < k J µ5 (0) k >= u p (k )[ iγ µ γ 5 F(q 2 ) + q µ γ 5 G(q 2 ) + i[γ µ, γ ν ]γ 5 q ν F 3 (q 2 )]u n (k) And similarly we obtain: < 0 J µ 5 (0) π(k) >= if πk µ
29 Problems with strongly interacting particles In general a pertubation theory is not well defined.
30 Breaking of chiral symmetry M π 139MeV << 938Mev m N M π 0 Is it possible that the pion is a Nambu-Goldstone Boson?
31 Breaking of chiral symmetry M π 139MeV << 938Mev m N M π 0 Is it possible that the pion is a Nambu-Goldstone Boson? Suppose µ J µ 5 (x)=0 i.e. chiral symmetry holds then: < 0 J µ 5 (0) π(k) >= if πk µ < 0 J 0 (0) n > 0 < π π(0) 0 >= 1 < n Φ(0) 0 > 0
32 Breaking of chiral symmetry M π 139MeV << 938Mev m N M π 0 Is it possible that the pion is a Nambu-Goldstone Boson? Suppose µ J µ 5 (x)=0 i.e. chiral symmetry holds then: < 0 J µ 5 (0) π(k) >= if πk µ < 0 J 0 (0) n > 0 < π π(0) 0 >= 1 < n Φ(0) 0 > 0 Pion as a Nambu-Goldstone Boson The Pion is a Nambu-Goldstone Boson in a world in which chiral symmetry holds.
33 Is the Pion massless? If chiral symmetry holds then: ik µ < 0 J µ 5 (0) π(k) > exp( ik x) = µ < 0 J µ 5 (0) π(k) > exp( ik x) =< 0 µ J µ 5 (x) π(k) >= 0
34 Is the Pion massless? If chiral symmetry holds then: ik µ < 0 J µ 5 (0) π(k) > exp( ik x) = µ < 0 J µ 5 (0) π(k) > exp( ik x) =< 0 µ J µ 5 (x) π(k) >= 0 k µ < 0 J µ 5 (0) π(k) >= if πk µ k µ = if π M 2 π Thus µ J µ 5 (x)=0 implies that M2 π=0
35 Goldberger-Treiman relation q µ < k J µ5 (0) k > = i < k µ J µ5 (x) k > exp( iq x) = 0 q µ < k J µ5 (0) k > = q µ ū p (k )[ iγ µ γ 5 F(q 2 ) + q µ γ 5 G(q 2 ) + i[γ µ, γ ν ]γ 5 q ν F 3 (q 2 )]u n (k) = ū N (k )[(k µ ( i)γ µ γ 5 F(q 2 ) k µ ( i)γ µ γ 5 F(q 2 ) + q 2 γ 5 G(q 2 ) + i[γ µ, γ ν ]γ 5 q ν q µ F 3 (q 2 )]u N (k) = γ 5 [2m N F(q 2 ) + q 2 G(q 2 )] = 0 by using the Dirac equation: ū N (k )(k µγ µ im N ) = (k µ γ µ im N )u N (k) = 0 But if q 0 this implies m N = 0!?!
36 Goldberger-Treiman relation this diagram gives a contribution if π q µ i q 2 G πnn ū N (k )γ 5 u N (k) Note that there are still infinitely many diagrams which have a pole at q 2 = 0 G(q 2 ) F π 1 q 2 G πnn for q 0 Goldberger-Treiman relation G πnn = 2m Ng A F π with g A = F (0)
37 Experimental test of Goldberger-Treiman relation m N = (m p + m n ) 2 g A = 1, 257 F π = 93MeV G GTR πnn 25.4 G πnn = 27.0 = 939.9MeV In good agreement with the experiment.
38 Experimental test of Goldberger-Treiman relation m N = (m p + m n ) 2 g A = 1, 257 F π = 93MeV G GTR πnn 25.4 G πnn = 27.0 = 939.9MeV In good agreement with the experiment. Please note that this result is quite general. No assumptions about the broken symmetry have been made.
39 More about chiral symmetry The Lagrangian of strong interaction: L = ūγ µ D µ u dγ µ D µ d + m u (ū R u L + ū L u R ) + m d ( d L d R + d R d L ) +... has a SU(2) V SU(2) A symmetry in the case m u = m d = 0. q q = exp(iθ V τ + iγ 5ΘA τ)q with τ the isospin (Pauli) matrices.
40 More about chiral symmetry The Lagrangian of strong interaction: L = ūγ µ D µ u dγ µ D µ d + m u (ū R u L + ū L u R ) + m d ( d L d R + d R d L ) +... has a SU(2) V SU(2) A symmetry in the case m u = m d = 0. q q = exp(i Θ V τ + iγ 5 ΘA τ)q with τ the isospin (Pauli) matrices. And the conserved currents: with charges: J µ = i qγ µ τq and J µ 5 = i qγ µγ 5 τq Q V = d 3 x J 0 ( x, t) Q A = d 3 x J5 0 ( x, t)
41 More about chiral symmetry They act in the following way on q: [ Q V, q] = τq [ Q A, q] = γ 5 τq So if the symmetry is unbroken Q A transforms a state h> into a state of Q A h > of opposite parity. No such parity doubling is observed in the hadron spectrum. Conclude that SU(2) V SU(2) A is broken to SU(2) V isospin group. The three Pions are the three Nambu-Goldstone Bosons of the three currents J µ 5.
42 Summary/Remarks Breaking of a continuous global symmetry leads to Nambu-Goldstone Bosons. No information about how the breaking occurs is needed. Natural explanation for smallness of Pion mass. Found a technique to relate infinitly many diagramms.
43 Summary/Remarks Breaking of a continuous global symmetry leads to Nambu-Goldstone Bosons. No information about how the breaking occurs is needed. Natural explanation for smallness of Pion mass. Found a technique to relate infinitly many diagramms. From the assumption that Pions and even Kaons and the Eta are Goldstone bosons one can construct effective field theories like non-linear sigma model or chiral pertubation theory. The QCD Lagrangian for massless Quarks has two other global symmetries. One, U(1) V implies Baryon-number conservation. The other one, U(1) A will be treated next week.
44 Summary/Remarks Breaking of a continuous global symmetry leads to Nambu-Goldstone Bosons. No information about how the breaking occurs is needed. Natural explanation for smallness of Pion mass. Found a technique to relate infinitly many diagramms. From the assumption that Pions and even Kaons and the Eta are Goldstone bosons one can construct effective field theories like non-linear sigma model or chiral pertubation theory. The QCD Lagrangian for massless Quarks has two other global symmetries. One, U(1) V implies Baryon-number conservation. The other one, U(1) A will be treated next week. Thank you
45 Sources A. Zee, Quantum field theory in a nutshell, Princeton University press 2001 S. Weinberg, The quantum theory of fields II, Camebridge University Press 1996 Ta-Pei Cheng and Ling-Fong Li, Gauge theory of elementary particles, Oxford University Press 1984 Michael Peskin and Daniel Schroeder, An introduction to quantum field theory, Perseus Books, 1995
Group Structure of Spontaneously Broken Gauge Theories
Group Structure of SpontaneouslyBroken Gauge Theories p. 1/25 Group Structure of Spontaneously Broken Gauge Theories Laura Daniel ldaniel@ucsc.edu Physics Department University of California, Santa Cruz
More informationGoldstone Bosons and Chiral Symmetry Breaking in QCD
Goldstone Bosons and Chiral Symmetry Breaking in QCD Michael Dine Department of Physics University of California, Santa Cruz May 2011 Before reading this handout, carefully read Peskin and Schroeder s
More informationPions are Special Contents Chiral Symmetry and Its Breaking Symmetries and Conservation Laws Goldstone Theorem The Potential Linear Sigma Model Wigner
Lecture 3 Pions as Goldstone Bosons of Chiral Symmetry Breaking Adnan Bashir, IFM, UMSNH, Mexico August 2013 Hermosillo Sonora Pions are Special Contents Chiral Symmetry and Its Breaking Symmetries and
More informationΛ QCD and Light Quarks Contents Symmetries of the QCD Lagrangian Chiral Symmetry and Its Breaking Parity and Handedness Parity Doubling Explicit Chira
Lecture 5 QCD Symmetries & Their Breaking From Quarks to Hadrons Adnan Bashir, IFM, UMSNH, Mexico August 2013 Hermosillo Sonora Λ QCD and Light Quarks Contents Symmetries of the QCD Lagrangian Chiral Symmetry
More informationAxions. Kerstin Helfrich. Seminar on Theoretical Particle Physics, / 31
1 / 31 Axions Kerstin Helfrich Seminar on Theoretical Particle Physics, 06.07.06 2 / 31 Structure 1 Introduction 2 Repetition: Instantons Formulae The θ-vacuum 3 The U(1) and the strong CP problem The
More informationLectures on Chiral Perturbation Theory
Lectures on Chiral Perturbation Theory I. Foundations II. Lattice Applications III. Baryons IV. Convergence Brian Tiburzi RIKEN BNL Research Center Chiral Perturbation Theory I. Foundations Low-energy
More informationSpontaneous symmetry breaking in particle physics: a case of cross fertilization. Giovanni Jona-Lasinio
Spontaneous symmetry breaking in particle physics: a case of cross fertilization Giovanni Jona-Lasinio QUARK MATTER ITALIA, 22-24 aprile 2009 1 / 38 Spontaneous (dynamical) symmetry breaking Figure: Elastic
More informationIntroduction to chiral perturbation theory II Higher orders, loops, applications
Introduction to chiral perturbation theory II Higher orders, loops, applications Gilberto Colangelo Zuoz 18. July 06 Outline Introduction Why loops? Loops and unitarity Renormalization of loops Applications
More informationIntroduction to particle physics Lecture 6
Introduction to particle physics Lecture 6 Frank Krauss IPPP Durham U Durham, Epiphany term 2009 Outline 1 Fermi s theory, once more 2 From effective to full theory: Weak gauge bosons 3 Massive gauge bosons:
More informationTheory toolbox. Chapter Chiral effective field theories
Chapter 3 Theory toolbox 3.1 Chiral effective field theories The near chiral symmetry of the QCD Lagrangian and its spontaneous breaking can be exploited to construct low-energy effective theories of QCD
More informationQCD in the light quark (up & down) sector (QCD-light) has two mass scales M(GeV)
QCD in the light quark (up & down) sector (QCD-light) has two mass scales M(GeV) 1 m N m ρ Λ QCD 0 m π m u,d In a generic physical system, there are often many scales involved. However, for a specific
More informationParticle Physics I Lecture Exam Question Sheet
Particle Physics I Lecture Exam Question Sheet Five out of these 16 questions will be given to you at the beginning of the exam. (1) (a) Which are the different fundamental interactions that exist in Nature?
More informationThe Gauge Principle Contents Quantum Electrodynamics SU(N) Gauge Theory Global Gauge Transformations Local Gauge Transformations Dynamics of Field Ten
Lecture 4 QCD as a Gauge Theory Adnan Bashir, IFM, UMSNH, Mexico August 2013 Hermosillo Sonora The Gauge Principle Contents Quantum Electrodynamics SU(N) Gauge Theory Global Gauge Transformations Local
More information( ) 2 = #$ 2 % 2 + #$% 3 + # 4 % 4
PC 477 The Early Universe Lectures 9 & 0 One is forced to make a choice of vacuum, and the resulting phenomena is known as spontaneous symmetry breaking (SSB.. Discrete Goldstone Model L =! µ"! µ " # V
More informationAnomalies and discrete chiral symmetries
Anomalies and discrete chiral symmetries Michael Creutz BNL & U. Mainz Three sources of chiral symmetry breaking in QCD spontaneous breaking ψψ 0 explains lightness of pions implicit breaking of U(1) by
More informationPart III The Standard Model
Part III The Standard Model Theorems Based on lectures by C. E. Thomas Notes taken by Dexter Chua Lent 2017 These notes are not endorsed by the lecturers, and I have modified them (often significantly)
More informationAn Introduction to the Standard Model of Particle Physics
An Introduction to the Standard Model of Particle Physics W. N. COTTINGHAM and D. A. GREENWOOD Ж CAMBRIDGE UNIVERSITY PRESS Contents Preface. page xiii Notation xv 1 The particle physicist's view of Nature
More information2.4 Parity transformation
2.4 Parity transformation An extremely simple group is one that has only two elements: {e, P }. Obviously, P 1 = P, so P 2 = e, with e represented by the unit n n matrix in an n- dimensional representation.
More informationThe chiral anomaly and the eta-prime in vacuum and at low temperatures
The chiral anomaly and the eta-prime in vacuum and at low temperatures Stefan Leupold, Carl Niblaeus, Bruno Strandberg Department of Physics and Astronomy Uppsala University St. Goar, March 2013 1 Table
More informationThe Phases of QCD. Thomas Schaefer. North Carolina State University
The Phases of QCD Thomas Schaefer North Carolina State University 1 Motivation Different phases of QCD occur in the universe Neutron Stars, Big Bang Exploring the phase diagram is important to understanding
More informationThe SU(3) Group SU(3) and Mesons Contents Quarks and Anti-quarks SU(3) and Baryons Masses and Symmetry Breaking Gell-Mann Okubo Mass Formulae Quark-Mo
Lecture 2 Quark Model The Eight Fold Way Adnan Bashir, IFM, UMSNH, Mexico August 2014 Culiacán Sinaloa The SU(3) Group SU(3) and Mesons Contents Quarks and Anti-quarks SU(3) and Baryons Masses and Symmetry
More informationarxiv:hep-ph/ v1 1 Feb 2005
Vector Goldstone Boson and Lorentz Invariance arxiv:hep-ph/050011v1 1 Feb 005 Ling-Fong Li Department of Physics, Carnegie Mellon University, Pittsburgh, PA 1513 January 5, 018 Abstract Spontanous symmetry
More informationThe Strong Interaction and LHC phenomenology
The Strong Interaction and LHC phenomenology Juan Rojo STFC Rutherford Fellow University of Oxford Theoretical Physics Graduate School course Lecture 2: The QCD Lagrangian, Symmetries and Feynman Rules
More informationDonoghue, Golowich, Holstein Chapter 4, 6
1 Week 7: Non linear sigma models and pion lagrangians Reading material from the books Burgess-Moore, Chapter 9.3 Donoghue, Golowich, Holstein Chapter 4, 6 Weinberg, Chap. 19 1 Goldstone boson lagrangians
More informationAnomaly. Kenichi KONISHI University of Pisa. College de France, 14 February 2006
Anomaly Kenichi KONISHI University of Pisa College de France, 14 February 2006 Abstract Symmetry and quantization U A (1) anomaly and π 0 decay Origin of anomalies Chiral and nonabelian anomaly Anomally
More informationIntroduction to gauge theory
Introduction to gauge theory 2008 High energy lecture 1 장상현 연세대학교 September 24, 2008 장상현 ( 연세대학교 ) Introduction to gauge theory September 24, 2008 1 / 72 Table of Contents 1 Introduction 2 Dirac equation
More informationNational Nuclear Physics Summer School Lectures on Effective Field Theory. Brian Tiburzi. RIKEN BNL Research Center
2014 National Nuclear Physics Summer School Lectures on Effective Field Theory I. Removing heavy particles II. Removing large scales III. Describing Goldstone bosons IV. Interacting with Goldstone bosons
More informationHow nucleon gets its mass
Fiz-Tech, Dec 05, 2006 How nucleon gets its mass Dmitri Diakonov Petersburg Nuclear Physics Institute 1. Quantum Chromodynamics: the theory of strong interactions 2. Chiral symmetry of strong interactions
More informationt Hooft Determinant at Finite Temperature with Fluctuations
t Hooft Determinant at Finite Temperature with Fluctuations Mario Mitter In collaboration with: Bernd-Jochen Schaefer, Nils Strodthoff, Lorenz von Smekal (former) PhD Advisers: Reinhard Alkofer, Bernd-Jochen
More informationHadron Physics & Quantum Chromodynamics Adnan Bashir, IFM, UMSNH, Mexico August 2013 Hermosillo Sonora
Hadron Physics & Quantum Chromodynamics Adnan Bashir, IFM, UMSNH, Mexico August 2013 Hermosillo Sonora Hadron Physics & QCD Part 1: First Encounter With Hadrons: Introduction to Mesons & Baryons, The Quark
More informationSpontaneous breaking of supersymmetry
Spontaneous breaking of supersymmetry Hiroshi Suzuki Theoretical Physics Laboratory Nov. 18, 2009 @ Theoretical science colloquium in RIKEN Hiroshi Suzuki (TPL) Spontaneous breaking of supersymmetry Nov.
More informationIntroduction to the Standard Model New Horizons in Lattice Field Theory IIP Natal, March 2013
Introduction to the Standard Model New Horizons in Lattice Field Theory IIP Natal, March 2013 Rogerio Rosenfeld IFT-UNESP Lecture 1: Motivation/QFT/Gauge Symmetries/QED/QCD Lecture 2: QCD tests/electroweak
More informationSTANDARD MODEL and BEYOND: SUCCESSES and FAILURES of QFT. (Two lectures)
STANDARD MODEL and BEYOND: SUCCESSES and FAILURES of QFT (Two lectures) Lecture 1: Mass scales in particle physics - naturalness in QFT Lecture 2: Renormalisable or non-renormalisable effective electroweak
More informationQFT at finite Temperature
Benjamin Eltzner Seminar on Theoretical Elementary Particle Physics and QFT, 13.07.06 Content 1 Path Integral and Partition Function Classical Partition Function The Quantum Mechanical Partition Function
More informationThe Standard Model of Electroweak Physics. Christopher T. Hill Head of Theoretical Physics Fermilab
The Standard Model of Electroweak Physics Christopher T. Hill Head of Theoretical Physics Fermilab Lecture I: Incarnations of Symmetry Noether s Theorem is as important to us now as the Pythagorean Theorem
More informationPHYSICS PARTICLE. An Introductory Course of. Palash B. Pal. CRC Press. Saha Institute of Nuclear Physics. Kolkata, India. Taylor &.
An Introductory Course of PARTICLE PHYSICS Palash B. Pal Saha Institute of Nuclear Physics Kolkata, India W CRC Press Taylor &. Francis Croup Boca Raton London New York CRC Press is an imprint of the &
More informationSolutions to gauge hierarchy problem. SS 10, Uli Haisch
Solutions to gauge hierarchy problem SS 10, Uli Haisch 1 Quantum instability of Higgs mass So far we considered only at RGE of Higgs quartic coupling (dimensionless parameter). Higgs mass has a totally
More informationQCD and the Nambu Jona-Lasinio Model
Lecture 1 QCD and the Nambu Jona-Lasinio Model Ian Cloët The University of Adelaide & Argonne National Laboratory CSSM Summer School Non-perturbative Methods in Quantum Field Theory 11 th 15 th February
More informationOverview of low energy NN interaction and few nucleon systems
1 Overview of low energy NN interaction and few nucleon systems Renato Higa Theory Group, Jefferson Lab Cebaf Center, A3 (ext6363) higa@jlaborg Lecture II Basics on chiral EFT π EFT Chiral effective field
More informationThis means that n or p form a doublet under isospin transformation. Isospin invariance simply means that. [T i, H s ] = 0
1 QCD 1.1 Quark Model 1. Isospin symmetry In early studies of nuclear reactions, it was found that, to a good approximation, nuclear force is independent of the electromagnetic charge carried by the nucleons
More informationPARTICLE PHYSICS Major Option
PATICE PHYSICS Major Option Michaelmas Term 00 ichard Batley Handout No 8 QED Maxwell s equations are invariant under the gauge transformation A A A χ where A ( φ, A) and χ χ ( t, x) is the 4-vector potential
More informationLecture 6 The Super-Higgs Mechanism
Lecture 6 The Super-Higgs Mechanism Introduction: moduli space. Outline Explicit computation of moduli space for SUSY QCD with F < N and F N. The Higgs mechanism. The super-higgs mechanism. Reading: Terning
More informationQuark Model. Ling-Fong Li. (Institute) Note 8 1 / 26
Quark Model Ling-Fong Li (Institute) Note 8 1 / 6 QCD Quark Model Isospin symmetry To a good approximation, nuclear force is independent of the electric charge carried by the nucleons charge independence.
More informationCold and dense QCD matter
Cold and dense QCD matter GCOE sympodium Feb. 15, 2010 Yoshimasa Hidaka Quantum ChromoDynamics Atom Electron 10-10 m Quantum ChromoDynamics Atom Nucleon Electron 10-10 m 10-15 m Quantum ElectroDynamics
More informationNTNU Trondheim, Institutt for fysikk
NTNU Trondheim, Institutt for fysikk Examination for FY3464 Quantum Field Theory I Contact: Michael Kachelrieß, tel. 99890701 Allowed tools: mathematical tables Some formulas can be found on p.2. 1. Concepts.
More informationElectric Dipole Moments and the strong CP problem
Electric Dipole Moments and the strong CP problem We finally understand CP viola3on.. QCD theta term Jordy de Vries, Nikhef, Amsterdam Topical Lectures on electric dipole moments, Dec. 14-16 Introductory
More informationchapter 3 Spontaneous Symmetry Breaking and
chapter 3 Spontaneous Symmetry Breaking and Nambu-Goldstone boson History 1961 Nambu: SSB of chiral symmetry and appearance of zero mass boson Goldstone s s theorem in general 1964 Higgs (+others): consider
More informationNon Abelian Higgs Mechanism
Non Abelian Higgs Mechanism When a local rather than global symmetry is spontaneously broken, we do not get a massless Goldstone boson. Instead, the gauge field of the broken symmetry becomes massive,
More informationCHIRAL SYMMETRY OF EXCITED HADRONS FROM PHENOMENOLOGY, THEORY AND LATTICE
CHIRAL SYMMETRY OF EXCITED HADRONS FROM PHENOMENOLOGY, THEORY AND LATTICE L. Ya. Glozman Institut für Physik, FB Theoretische Physik, Universität Graz L.Ya. Glozman Contents of the Talk Chiral symmetry
More informationLecture 03. The Standard Model of Particle Physics. Part II The Higgs Boson Properties of the SM
Lecture 03 The Standard Model of Particle Physics Part II The Higgs Boson Properties of the SM The Standard Model So far we talked about all the particles except the Higgs If we know what the particles
More informationThe symmetries of QCD (and consequences)
The symmetries of QCD (and consequences) Sinéad M. Ryan Trinity College Dublin Quantum Universe Symposium, Groningen, March 2018 Understand nature in terms of fundamental building blocks The Rumsfeld
More informationSymmetry Groups conservation law quantum numbers Gauge symmetries local bosons mediate the interaction Group Abelian Product of Groups simple
Symmetry Groups Symmetry plays an essential role in particle theory. If a theory is invariant under transformations by a symmetry group one obtains a conservation law and quantum numbers. For example,
More informationLecture 3. 6 October 2016
Lecture 3 6 October 016 1 Effective field theory Doing physics, we are usually interested in phenomena at particular energy scales. Given a full theory at hand, one can perform computations at any energy
More informationSymmetries in Effective Field Theory
Symmetries in Effective Field Theory Sourendu Gupta Mini School 2016, IACS Kolkata, India Effective Field Theories 29 February 4 March, 2016 Outline Outline Symmetries in EFTs Softly broken symmetries
More informationStandard Model & Beyond
XI SERC School on Experimental High-Energy Physics National Institute of Science Education and Research 13 th November 2017 Standard Model & Beyond Lecture III Sreerup Raychaudhuri TIFR, Mumbai 2 Fermions
More informationHunting New Physics in the Higgs Sector
HS Hunting New Physics in the Higgs Sector SM Higgs Sector - Test of the Higgs Mechanism Oleg Kaikov KIT, Seminar WS 2015/16 Prof. Dr. M. Margarete Mühlleitner, Dr. Roger Wolf, Dr. Hendrik Mantler Advisor:
More informationChiral and angular momentum content of rho and rho mesons from dynamical lattice calculations
Chiral and angular momentum content of rho and rho mesons from dynamical lattice calculations L. Ya. Glozman Institut für Physik, FB Theoretische Physik, Universität Graz With Christian Lang and Markus
More informationAcknowledgements An introduction to unitary symmetry The search for higher symmetries p. 1 The eight-baryon puzzle p. 1 The elimination of
Preface p. xiii Acknowledgements p. xiv An introduction to unitary symmetry The search for higher symmetries p. 1 The eight-baryon puzzle p. 1 The elimination of G[subscript 0] p. 4 SU(3) and its representations
More informationη π 0 γγ decay in the three-flavor Nambu Jona-Lasinio model
TIT/HEP-38/NP INS-Rep.-3 η π 0 γγ decay in the three-flavor Nambu Jona-Lasinio model arxiv:hep-ph/96053v 8 Feb 996 Y.Nemoto, M.Oka Department of Physics, Tokyo Institute of Technology, Meguro, Tokyo 5,
More informationSymmetries in Effective Field Theory
Symmetries in Effective Field Theory Sourendu Gupta SERC Main School 2014, BITS Pilani Goa, India Effective Field Theories December, 2014 Outline Outline Symmetries in EFTs Softly broken symmetries in
More informationAxial symmetry in the chiral symmetric phase
Axial symmetry in the chiral symmetric phase Swagato Mukherjee June 2014, Stoney Brook, USA Axial symmetry in QCD massless QCD Lagrangian is invariant under U A (1) : ψ (x) e i α ( x) γ 5 ψ(x) μ J 5 μ
More informationConfined chirally symmetric dense matter
Confined chirally symmetric dense matter L. Ya. Glozman, V. Sazonov, R. Wagenbrunn Institut für Physik, FB Theoretische Physik, Universität Graz 28 June 2013 L. Ya. Glozman, V. Sazonov, R. Wagenbrunn (Institut
More informationGenesis of Electroweak. Unification
Unification Tom Kibble Imperial College London ICTP October 2014 1 Outline Development of the electroweak theory, which incorporates the idea of the Higgs boson as I saw it from my standpoint in Imperial
More informationMay 7, Physics Beyond the Standard Model. Francesco Fucito. Introduction. Standard. Model- Boson Sector. Standard. Model- Fermion Sector
- Boson - May 7, 2017 - Boson - The standard model of particle physics is the state of the art in quantum field theory All the knowledge we have developed so far in this field enters in its definition:
More informationLorentz-covariant spectrum of single-particle states and their field theory Physics 230A, Spring 2007, Hitoshi Murayama
Lorentz-covariant spectrum of single-particle states and their field theory Physics 30A, Spring 007, Hitoshi Murayama 1 Poincaré Symmetry In order to understand the number of degrees of freedom we need
More informationGeometry and Physics. Amer Iqbal. March 4, 2010
March 4, 2010 Many uses of Mathematics in Physics The language of the physical world is mathematics. Quantitative understanding of the world around us requires the precise language of mathematics. Symmetries
More informationRelativistic Waves and Quantum Fields
Relativistic Waves and Quantum Fields (SPA7018U & SPA7018P) Gabriele Travaglini December 10, 2014 1 Lorentz group Lectures 1 3. Galileo s principle of Relativity. Einstein s principle. Events. Invariant
More informationAnomalies, gauge field topology, and the lattice
Anomalies, gauge field topology, and the lattice Michael Creutz BNL & U. Mainz Three sources of chiral symmetry breaking in QCD spontaneous breaking ψψ 0 explains lightness of pions implicit breaking of
More informationPAPER 305 THE STANDARD MODEL
MATHEMATICAL TRIPOS Part III Tuesday, 6 June, 017 9:00 am to 1:00 pm PAPER 305 THE STANDARD MODEL Attempt no more than THREE questions. There are FOUR questions in total. The questions carry equal weight.
More informationIntroduction to particle physics Lecture 12: Weak interactions
Introduction to particle physics Lecture 12: Weak interactions Frank Krauss IPPP Durham U Durham, Epiphany term 2010 1 / 22 Outline 1 Gauge theory of weak interactions 2 Spontaneous symmetry breaking 3
More informationExotics in meson-baryon dynamics with chiral symmetry
Dissertation Submitted to Graduate School of Science of Osaka University for the Degree of Doctor of Physics Exotics in meson-baryon dynamics with chiral symmetry Tetsuo Hyodo A) 006 Research Center for
More informationMeson-Nucleon Coupling. Nobuhito Maru
Meson-Nucleon Coupling from AdS/QCD Nobuhito Maru (Chuo Univ.) with Motoi Tachibana (Saga Univ.) arxiv:94.3816 (Accepted in in EPJC) 7/9/9 workshop@yitp Plan 1: Introduction : Meson sector (review) 3:
More informationSECOND PUBLIC EXAMINATION. Honour School of Physics Part C: 4 Year Course. Honour School of Physics and Philosophy Part C C4: PARTICLE PHYSICS
754 SECOND PUBLIC EXAMINATION Honour School of Physics Part C: 4 Year Course Honour School of Physics and Philosophy Part C C4: PARTICLE PHYSICS TRINITY TERM 04 Thursday, 9 June,.30 pm 5.45 pm 5 minutes
More informationFundamental Physics: Quantum Field Theory
Mobolaji Williams (mwilliams@physics.harvard.edu x) First Version: June 1, 216 Fundamental Physics: Quantum Field Theory What is the topic? Quantum field theory refers to the quantum theory of fields in
More informationVector Mesons and an Interpretation of Seiberg Duality
Vector Mesons and an Interpretation of Seiberg Duality p. 1/?? Vector Mesons and an Interpretation of Seiberg Duality Zohar Komargodski Institute for Advanced Study, Princeton 1010.4105 Vector Mesons and
More informationHiggs Boson Phenomenology Lecture I
iggs Boson Phenomenology Lecture I Laura Reina TASI 2011, CU-Boulder, June 2011 Outline of Lecture I Understanding the Electroweak Symmetry Breaking as a first step towards a more fundamental theory of
More informationTextbook Problem 4.2: We begin by developing Feynman rules for the theory at hand. The Hamiltonian clearly decomposes into Ĥ = Ĥ0 + ˆV where
PHY 396 K. Solutions for problem set #11. Textbook Problem 4.2: We begin by developing Feynman rules for the theory at hand. The Hamiltonian clearly decomposes into Ĥ = Ĥ0 + ˆV where Ĥ 0 = Ĥfree Φ + Ĥfree
More informationElectroweak physics and the LHC an introduction to the Standard Model
Electroweak physics and the LHC an introduction to the Standard Model Paolo Gambino INFN Torino LHC School Martignano 12-18 June 2006 Outline Prologue on weak interactions Express review of gauge theories
More informationThe Phases of QCD. Thomas Schaefer. North Carolina State University
The Phases of QCD Thomas Schaefer North Carolina State University 1 Plan of the lectures 1. QCD and States of Matter 2. The High Temperature Phase: Theory 3. Exploring QCD at High Temperature: Experiment
More informationThe mass of the Higgs boson
The mass of the Higgs boson LHC : Higgs particle observation CMS 2011/12 ATLAS 2011/12 a prediction Higgs boson found standard model Higgs boson T.Plehn, M.Rauch Spontaneous symmetry breaking confirmed
More informationThe Higgs amplitude mode at the two-dimensional superfluid/mott insulator transition
The Higgs amplitude mode at the two-dimensional superfluid/mott insulator transition M. Endres et al., Nature 487 (7408), p. 454-458 (2012) October 29, 2013 Table of contents 1 2 3 4 5 Table of contents
More informationPAPER 45 THE STANDARD MODEL
MATHEMATICAL TRIPOS Part III Friday, 6 June, 014 1:0 pm to 4:0 pm PAPER 45 THE STANDARD MODEL Attempt no more than THREE questions. There are FOUR questions in total. The questions carry equal weight.
More informationMichael Buballa. Theoriezentrum, Institut für Kernphysik, TU Darmstadt
Vacuum-fluctuation effects on inhomogeneous chiral condensates Michael Buballa Theoriezentrum, Institut für Kernphysik, TU Darmstadt International School of Nuclear Physics 38 th Course Nuclear matter
More informationIsospin. K.K. Gan L5: Isospin and Parity 1
Isospin Isospin is a continuous symmetry invented by Heisenberg: Explain the observation that the strong interaction does not distinguish between neutron and proton. Example: the mass difference between
More informationRenormalization Group Study of the Chiral Phase Transition
Renormalization Group Study of the Chiral Phase Transition Ana Juričić, Bernd-Jochen Schaefer University of Graz Graz, May 23, 2013 Table of Contents 1 Proper Time Renormalization Group 2 Quark-Meson Model
More informationHomework 3: Group Theory and the Quark Model Due February 16
Homework 3: Group Theory and the Quark Model Due February 16 1. Lorentz Group. From the defining requirement that a Lorentz transformation implemented by a matrix Λ leave the metric invariant: Λ µ ρη ρσ
More informationEDMs from the QCD θ term
ACFI EDM School November 2016 EDMs from the QCD θ term Vincenzo Cirigliano Los Alamos National Laboratory 1 Lecture II outline The QCD θ term Toolbox: chiral symmetries and their breaking Estimate of the
More informationIntroduction to particle physics Lecture 9: Gauge invariance
Introduction to particle physics Lecture 9: Gauge invariance Frank Krauss IPPP Durham U Durham, Epiphany term 2010 1 / 17 Outline 1 Symmetries 2 Classical gauge invariance 3 Phase invariance 4 Generalised
More informationHIGH DENSITY NUCLEAR CONDENSATES. Paulo Bedaque, U. of Maryland (Aleksey Cherman & Michael Buchoff, Evan Berkowitz & Srimoyee Sen)
HIGH DENSITY NUCLEAR CONDENSATES Paulo Bedaque, U. of Maryland (Aleksey Cherman & Michael Buchoff, Evan Berkowitz & Srimoyee Sen) What am I talking about? (Gabadadze 10, Ashcroft 89) deuterium/helium at
More informationFoundations of Physics III Quantum and Particle Physics Lecture 13
Foundations of Physics III Quantum and Particle Physics Lecture 13 Frank Krauss February 27, 2012 1 Construction of the Standard Model 2 The Standard Model: Tests and status 3 Beyond the Standard Model?
More informationarxiv: v2 [nucl-th] 22 Jul 2013
Broken Chiral Symmetry on a Null Plane arxiv:1302.1600v2 [nucl-th] 22 Jul 2013 Silas R. Beane 1 Helmholtz-Institut für Strahlen- und Kernphysik (Theorie), Universität Bonn, D-53115 Bonn, Germany beane@hiskp.uni-bonn.de
More informationSymmetries of QCD and in-medium physics
Symmetries of QCD and in-medium physics Stefan Leupold Indian-Summer School, Physics@FAIR, Rez, October 2011 Table of Contents 1 Introduction 2 Global symmetries of QCD 3 Spontaneous symmetry breaking
More informationStrong coupling constant. 12π ( 22 2n f ) ln Q 2 2. The spa1al separa1on between quarks goes as ! = " Q 2
Strong coupling constant In quantum field theory, the coupling constant is an effec1ve constant, which depends on four- momentum Q 2 transferred. For strong interac1ons, the Q 2 dependence is very strong
More informationRenormalization group methods in nuclear few- and many-body problems
Renormalization group methods in nuclear few- and many-body problems Lecture 2 S.K. Bogner (NSCL/MSU) 2011 National Nuclear Physics Summer School University of North Carolina at Chapel Hill Lecture 2 outline
More informationWeek 3: Renormalizable lagrangians and the Standard model lagrangian 1 Reading material from the books
Week 3: Renormalizable lagrangians and the Standard model lagrangian 1 Reading material from the books Burgess-Moore, Chapter Weiberg, Chapter 5 Donoghue, Golowich, Holstein Chapter 1, 1 Free field Lagrangians
More informationT 1! p k. = T r! k., s k. ', x' ] = i!, s y. ', s y
Time Reversal r k ' = r k = T r k T 1 p k ' = p k, s k ' = s k T cannot be represented by an unitary operator. Unitary opera$ons preserve algebraic rela$ons between operators, while T changes the sign
More informationCitation PHYSICAL REVIEW LETTERS (2000), 84( RightCopyright 2000 American Physical So
Title Chiral-symmetry realization resonances for eve Author(s) Jido, D; Hatsuda, T; Kunihiro, T Citation PHYSICAL REVIEW LETTERS (000), 84( Issue Date 000-04-0 URL http://hdl.handle.net/433/5059 RightCopyright
More informationCritical lines and points. in the. QCD phase diagram
Critical lines and points in the QCD phase diagram Understanding the phase diagram Phase diagram for m s > m u,d quark-gluon plasma deconfinement quark matter : superfluid B spontaneously broken nuclear
More informationElectroweak Theory: 2
Electroweak Theory: 2 Introduction QED The Fermi theory The standard model Precision tests CP violation; K and B systems Higgs physics Prospectus STIAS (January, 2011) Paul Langacker (IAS) 31 References
More informationAn Introduction to. Michael E. Peskin. Stanford Linear Accelerator Center. Daniel V. Schroeder. Weber State University. Advanced Book Program
An Introduction to Quantum Field Theory Michael E. Peskin Stanford Linear Accelerator Center Daniel V. Schroeder Weber State University 4B Advanced Book Program TT Addison-Wesley Publishing Company Reading,
More information