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International Workshop on Particle Physics and Cosmology after Higgs and Planck 后希格斯与普郎克粒子物理与宇宙学国际研讨会 September 5- 9 2013 Chongqing University of Posts and Telecommunications - PowerPoint PPT Presentation
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International Workshop on Particle Physics and Cosmology after Higgs and Planck 后希格斯与普郎克粒子物理与宇宙学国际研讨会 September 5-9 2013 Chongqing University of Posts and Telecommunications Chongqing China
Yue-Liang Wu
Kavli Institute for Theoretical Physics China (KITPC)
State Key Laboratory of Theoretical Physics (SKLTP)ITP-CAS
University of Chinese Academy of Sciences(UCAS)
Quantum Theory of Particles and Fields
Higgs Boson (上帝粒子) at LHC
Higgs Mass ~ 125 GeV
HC, DM, DE At Planck
Higgs Boson, Dark Matter, Dark Energy & Inflation
Mass Generation, WIMP, Vacuum Energy
Appearance of Mass/Energy Scale
Quantum Theory of Scalar & Gravitational Fields
Quantum Structure of Quadratic Divergence
Elementary Particle Physics基本粒子物理
QuantumMechanics量子力学
SpecialRelativity相对论 +
=
Quantum Field Theory and Symmetry
Symmetry Principle对称原理
=Quantum
Field Theory量子场论+
Basic Symmetry in Standard Model
Symmetry has played an important role in elementary particle physics
All known basic forces of nature: Electromagnetic, weak, strong & gravitational forces, are governed by the symmetries
U(1)_Y x SU(2)_L x SU(3)_c x SO(1,3) It has been found to be successfully
described by quantum field theory (QFT)
Divergence Problem in QFTs
QFTs cannot be defined by a straightforward perturbative expansion due to the presence of ultraviolet divergences. The divergences appear when developing
quantum electrodynamics (QED) in the 1930s by Max Born, Werner Heisenberg, Pascual Jordan, Paul Dirac.
The treatment of divergences was further described in the 1940s by Julian Schwinger, Richard Feynman, Shinichiro Tomonaga, and investigated systematically by Freeman Dyson.
QED
Freeman Dyson initiated the perturbative expansion of QED and proposed the renormalization of mass and coupling constant to treat the divergences
Freeman Dyson showed that these divergences or infinities are of a basic nature and cannot be eliminated by any formal mathematical procedures, such as the renormalization method
The divergence arises from the calculations of Feynman diagrams with closed loops of virtual particles It is because the integral region where all
particles in the loop have large energies and momenta
It is caused from the very short wavelength or high frequency fluctuations of the fields in the path integral
It is due to very short proper-time between particle emission and absorption when the loop is thought of as a sum over particle paths
Origin of Divergence in QFTs
Treatment on Divergence in QFT
Treatment of divergences is the key to understand the quantum structure of field theory. Regularization: Modifying the behavior of
field theory at very large momentum so Feynman diagrams become well-defined quantities
String/superstring: Underlying theory might not be a quantum theory of fields, it could be something else, string theory !?
Regularization Schemes in QFT Cut-off regularization Keeping divergent behavior, direct presence of energy scales spoiling gauge symmetry, translational/rotational
symmetries Pauli-Villars regularization Introducing superheavy particles, applicable to U(1) gauge
theory Destroying non-abelian gauge symmetry Dimensional regularization: analytic continuation in
dimension Gauge invariance, widely used for practical calculations Gamma_5 problem: questionable to chiral theory Dimension problem: unsuitable for super-symmetric theory Divergent behavior: losing quadratic behavior (incorrect gap eq.)
All the regularizations have their advantages & shortcomings
Dirac’s Criticism on QED Most physicists are very satisfied with the situation. They say: 'Quantum electrodynamics(QED) is a good theory and we do not have to worry about it any more.’ I must say that I am very dissatisfied with the situation, because this so-called 'good theory' does involve neglecting infinities which appear in its equations, neglecting them in an arbitrary way. This is just not sensible mathematics. Sensible mathematics involves neglecting a quantity when it is small - not neglecting it just because it is infinitely great and you do not want it! P.A.M. Dirac, “The Evolution of the Physicist‘s Picture of Nature,” in
Scientific American, May 1963, p. 53. Kragh, Helge ; Dirac: A scientific biography, CUP 1990, p. 184
Feynman’s Criticism on QED
The shell game that we play ... is technically called 'renormalization'. But no matter how clever the word, it is still what I would call a dippy process! Having to resort to such hocus-pocus has prevented us from proving that the theory of quantum electrodynamics(QED) is mathematically self-consistent. It's surprising that the theory still hasn't been proved self-consistent one way or the other by now; I suspect that renormalization is not mathematically legitimate.
Feynman, Richard P. ; QED, The Strange Theory of Light and Matter, Penguin 1990, p. 128
Why Quantum Field Theory So Successful
Folk’s theorem by Weinberg: Any quantum theory that at sufficiently low
energy and large distances looks Lorentz invariant and satisfies the cluster decomposition principle will also at sufficiently low energy look like a quantum field theory.
Indication: existence in any case a characterizing energy scale (CES) Mc
So that at sufficiently low energy gets meaningful
E << Mc QFTs
Why Quantum Field Theory So Successful Renormalization group Analysis by Wilson, Gell-Mann & Low Allow to deal with physical phenomena at
any interesting energy scale by integrating out the physics at higher energy scales.
Allow to define the renormalized theory at any interesting renormalization scale.
Implication: Existence of both charactering energy scale (CES) M_c and sliding energy scale(SES) μs which is not related to masses of particles.
Physical effects above SES μs can be integrated in the renormalized couplings and fields.
Why Quantum Field Theory So Successful More Indications Based on RG Analysis: Any QFT can be defined fundamentally with the
meaningful energy scale that has some physical significance.
Whatever the Lagrangian of QFTs was at the fundamental scale, as long as its couplings are sufficiently weak, it can be described at the interesting energy scales by a renormalizable effective Lagrangian of QFTs.Explanation to the renormalizability of QFTs and SM Electroweak interaction with spontaneous symmetry breaking has been shown to be a renormalizable theory
by t Hooft & Veltman QCD as the Yang-Mills gauge theory has been
shown to have an interesting property of asymptotic freedom
by Gross, Wilzck, Politz
Treatment on Divergence with Meaningful Regularization Scheme
(i) The regularization should be essential: It can lead to the well-defined Feynman
diagrams with physically meaningful energy scales to maintain the initial divergent behavior of integrals, so that the regularized theory only needs to make an infinity-free renormalization.
(ii) The regularization should be rigorous: It can maintain the basic symmetry principles
in the original theory, such as: gauge invariance, Lorentz invariance and translational invariance
(iii) The regularization should be general: It can be applied to the underlying
renormalizable QFTs (such as QCD), effective QFTs (like the gauged Nambu-Jona-Lasinio model), supersymmetric theories and chiral theories.
(iv) The regularization should also be simple: It can provide practical calculations.
Treatment on Divergences with Meaningful Regularization Scheme
Loop Regularization (LORE) Method The Loop Regularization method(LORE) 【 1 】【 2 】 realized in 4D space-time has been shown to satisfy all mentioned properties 【 1 】 Yue-Liang Wu, “Symmetry principle preserving and infinity free regularization and renormalization of quantum field theories and the mass gap” Int.J.Mod.Phys.A18:2003, 5363-5420.【 2 】 Yue-Liang Wu, “Symmetry-preserving loop regularization and renormalization of QFTs” Mod.Phys.Lett.A19:2004, 2191-2204. The key concept of LORE is the introduction of the
irreducible loop integrals(ILIs) which are evaluated from the Feynman diagrams
The crucial point in LORE method is the presence of two intrinsic energy scales introduced via the string-mode regulators in the regularization prescription acting on the ILIs.
These two intrinsic energy scales have been shown to play the roles of ultraviolet (UV) cut-off and infrared (IR) cut-off to avoid infinities without spoiling symmetries in original theory, and become meaningful as charactering energy scale and sliding energy scale
The LORE method has been proved with explicit calculations at one loop level that it can preserve non-Abelian gauge symmetry 【 3 】 and supersymmetry 【 4 】
The LORE method can provide a consistent calculation for the chiral anomaly 【 5 】 , radiatively induced Lorentz/CPT-violating Chern-Simons term in QED 【 6 】 , the QED trace anomaly 【 7 】
【 3 】 J.W.Cui and Y.L.Wu, One-Loop Renormalization of Non-Abelian Gauge Theory and \beta Function Based on Loop Regularization Method,’’ Int. J. Mod. Phys. A 23, 2861 (2008) [arXiv:0801.2199]【 4 】 J.W.Cui, Y.Tang and Y.L.Wu, “Renormalization of Supersymmetric Field Theories in Loop Regularization with String-mode Regulators”Phys. Rev. D 79, 125008 (2009) [arXiv:0812.0892 [hep-ph]].【 5 】 Y.L.Ma and Y.L.Wu, “Anomaly and anomaly-free treatment of QFTs based on symmetry-preserving loop regularization” Int. J. Mod. Phys. A 21, 6383 (2006) [arXiv:hep-ph/0509083].【 6 】 Y.L.Ma and Y.L.Wu, “On the radiatively induced Lorentz and CPT violating Chern-Simons term” Phys. Lett. B 647, 427 (2007) [arXiv:hep-ph/0611199].【 7 】 J.W. Cui, Y.L. Ma and Y.L. Wu, “Explicit derivation of the QED trace anomaly in symmetry-preserving loop regularization at one-loop level” Phys.Rev. D 84, 025020 (2011), arXiv:1103.2026 [hep-ph].
The LORE method allows us to derive the dynamically generated spontaneous chiral symmetry breaking of the low energy QCD 【 8 】 for understanding the dynamical quark masses and the mass spectra of light scalar and pseudoscalar mesons, as well the chiral symmetry restoration at finite temperature 【 9 】
The LORE method enables us to consistently carry out calculations on quantum gravitational contributions to gauge theories with asymptotic free power-law running 【 10–12 】 .
【 8 】 Y.B.Dai and Y.L.Wu,"Dynamically spontaneous symmetry breaking and masses of lightest nonet scalar mesons as composite Higgs bosons,’’ Eur. Phys. J. C 39 (2004) S1 [arXiv:hep-ph/0304075].【 9 】 D. Huang and Y.L. Wu, “Chiral Thermodynamic Model of QCD and its Critical Behavior in the Closed-Time-Path Green Function Approach”, arXiv:1110.4491 [hep-ph]【 10 】 Y.Tang and Y.L.Wu, “Gravitational Contributions to the Running of Gauge Couplings”, Commun. Theor. Phys. 54, 1040 (2010) [arXiv:0807.0331 [hep-ph]].【 11 】 Y.Tang and Y.L.Wu, “Quantum Gravitational Contributions to Gauge Field Theories” Commun. Theor. Phys.57, 629 (2012), arXiv:1012.0626 [hep-ph]【 12 】 Y.Tang and Y.L.Wu, “Gravitational Contributions to Gauge Green's Functions and Asymptotic Free Power-Law Running of Gauge Coupling” JHEP 1111, 073 (2011), arXiv:1109.4001 [hep-ph].
The LORE method has been applied to clarify the issue 【 13 】 raised by Gastmans, S.L. Wu and T.T. Wu. in the process H →γγ through a W-boson loop in the unitary gauge, and show that a finite amplitude still needs a consistent regularization for cancellation between tensor and scalar type divergent integrals
The LORE method has been applied to demonstrate consistently and explicitly the general structure of QFTs through higher-loop order calculations 【 14-15 】 .
In the LORE method, the evaluation of ILIs naturally merges to the Bjorken-Drell’s analogy between the Feynman diagrams and electric circuits 【 14-15 】 .
【 13 】 D.Huang,Y.Tang and Y.L.Wu “Note on Higgs Decay into Two Photons H→γγ”, Commun.Theor.Phys. 57 (2012) 427-434 , arXiv:1109.4846[hep-ph]【 14 】 D.Huang and Y.L. Wu,”Consistency and Advantage of Loop Regularization Method Merging with Bjorken-Drell's Analogy Between Feynman Diagrams and Electrical Circuits”, Eur.Phys.J. C72 (2012) 2066 , arXiv:1108.3603 [hep-ph]【 15 】 D. Huang, L.F. Li and Y.L. Wu, Consistency of Loop Regularization Method and Divergence Structure of QFTs Beyond One-Loop Order, Eur.Phys.J. C73 (2013) 2353, arXiv:1210.2794 [hep-ph]
Loop Regularization(LORE) Method Concept of Irreducible Loop Integrals(ILIs)
Scalar-type ILIs Tensor-type ILIs
LORE Method Prescription of LORE methodIn ILIs, make the following replacement
With the conditions for regulator masses and
coefficients
Which is resulted from the requirement:
regulator mass
coefficients
Divergence power ≥ the space-time dimension vanishes
Gauge Invariant Consistency Conditions
Checking Consistency Conditions
Checking Consistency Conditions
Vacuum Polarization Fermion-Loop Contributions
Gluonic Loop Contributions
Proper Treatment on Divergent Integrals
Lorentz decomposition & Naïve tensor manipulation
Violating gauge symmetry Tensor manipulation and integration don’t commute for divergent integrals
Direct Proof of Consistency Conditions
Consider the zero components and convergent integration over zero momentum component
Cut-Off & Dimensional Regularizations Cut-off violates consistency conditions
DR satisfies consistency conditions
Quadratic behavior is suppressed and the sign is opposite
0 when m 0, namely
LORE Method With String-mode Regulators
Choosing the regulator masses to have the string-mode Reggie trajectory behavior
with the conditions to recover original integrals and make regulator independent
result Coefficients are completely determined from the required conditionsDivergence power ≥ the space-time dimension vanishes
Explicit One Loop Feynman Integrals in LORE
With
Two intrinsic energy scales and play the roles of UV- and IR-cut off, but physically meaningful as the CES and SES
Euler constant =0.577216…
Compare to DR
LORE is an Infinity-Free Regularization!
Interesting Mathematical Identities
which lead the functions to the following explicit forms
General Evaluation of ILIs & UVDP Parameterization
Overall and vertex momentum conservations of Feynman diagrams
General structure of Feynman integral
Internal momentum (k_i) decomposition with loop momentum (l_r)and the undetermined internal currents flowing q_j
ILIs are resulted from the following conditions
Evaluation of ILIs and UVDP Parameterization
Writing the above conditions and momentum conservation into a more heuristic form
which determine currents flowing q_j
ILIs and Bjorken-Drell’s Circuit Analogy
Kirchhoff’s laws in the electric circuit analogy: sum of voltage drop around any closed loop is zero
Current conservation at vertex:q-- internal currents flowing in the circuit; p-- the external currents entering it
--- the resistance of the jth line or
Ohm’s Law
--- the conductance of the jth line--- the displacement between two pointsEquation of motion for a free
particle
--the causal propagation of a particle--the causality of Feynman propagator
ILIs and Bjorken-Drell’s Circuit Analogy
LORE Method Merging With Bjorken-Drell’s Circuit Analogy
Divergence of loop integral arises from infinite conductance Zero Resistance Short Circuit
Circuit analogy helps to treat properly all divergences in LORE
Loop momentum integral by diagonalizing the quadraticmomentum terms with an orthogonal transformation O
-- the eigenvalues of the matrix M--functions of UVDP parameters v_i
Feynman integrals are evaluated into ILIs
Evaluation of ILIs and UVDP Parameterization
The momentum integral on in ILIs reflects the overall divergence of the Feynman diagram
(k-1) internal loop momentum integrals are convergent
For the condition:
UV divergences for the loop integrals over l_(r) (r = 1…k −1) in the original subdiagrams are characterized by zero eigenvaluesλ_(r) → 0 (r =1…k − 1) of the matrix M
ILIs
Each zero eigenvalue λ_(r) → 0 infinity values of parameters singularity for parameter integrals
Divergence in UVDP-parameter space corresponds
to Divergence of subdiagram in momentum space
Regularized 1-fold ILIs for overall divergence of Feynman diagram
The LORE method naturally merges with Bjorken-Drell’s analogy between Feynman diagrams and electric circuits, and enables us to make a systematic procedure to all orders of Feynman diagrams
The LORE method has been realized in 4D space-time without modifying original Lagrangian, so it cannot be proved in the Lagrangian formalism to all orders
The Concept of ILIs and the Circuit Analogy of Feynman diagrams in LORE provides a diagrammatic approach for a general proof on the consistency of LORE method with the observation of one-to-one correspondence of divergences between UVDP parameters and subdiagrams of Feynman diagrams
Consistency and Advantage of LORE Method
Applicability of LORE Method
Why the calculation of finite amplitude for the Feynman diagrams in the standard model still needs a consistent regularization method ???
Issue on Higgs Decay into Two Photons Hγγ
Issues on Dimensional Regularization calculation for Higgs decay into two photon in unitary gauge by R. Gastmans, S.L. Wu and T.T. Wu
Question?
Not a divergent scalar-type ILI
The divergent tensor-type ILI
Naïve replacement in divergent integrals
W-boson contribution to 2 photon in unitary gauge
Amplitudes of three diagrams in unitary gauge
Divergent tensor-type & scalar-type integrals has an inconsistency relation in GWW paperRegularized Divergent ILIs in LORE have the consistency conditionThe difference is a finite part which is crucial to ensure gauge invariance by requiring the consistency condition
The Consistency of LORE Method with Explicit Calculations at One-Loop Level
Renormalization Constants of Non- Abelian gauge Theory and β Function of QCD in LORE Method
Lagrangian of gauge theory
Possible counter-terms
Ward-Takahaski-Slavnov-Taylor Identities
Gauge Invariance
Two-point Diagrams
Unlike DR which leads tadpole diagram to vanish, the LORE preserves original quadratic divergence of diagrams
Three-point Diagrams
Four-point Diagrams
Ward-Takahaski-Slavnov-Taylor Identities
Renormalization Constants in ξ gauge
Quadratic divergences cancel, all renormalization constants satisfy Ward-Takahaski-Slavnov-Taylor identities
Renormalization β Function
Gauge Coupling Renormalization
It reproduces the well-known QCD β function (GWP)
Supersymmetry-Preserving LORE Method
Supersymmetry Supersymmetry is a full symmetry of
quantum theory Supersymmetry is priory to gauge
symmetry for treating divergence The LORE is a supersymmetry- and
gauge symmetry-preserving regularization
J.W. Cui, Y.Tang,Y.L. Wu Phys.Rev.D79:125008,2009
Massless Wess-Zumino Model
Lagrangian
Ward identity
In momentum space
Check of Ward Identity
With gamma matrix algebra in exact 4-dimension and translational invariance of integral momentum quadratic divergences cancel LORE method satisfies these conditions
Massive Wess-Zumino Model
Lagrangian
Ward identity
Check of Ward Identity
With gamma matrix algebra in exact 4-dimension and translational invariance of integral momentum, thus quadratic divergences cancel LORE method satisfies these conditions
WARD IDENTITY IN SUPERSYMMETRIC GAUGE THEORY
Lagrangian (with source terms)
Infinitesimal supersymmetric transformation
Supersymmetric Ward identity
Contribution from Figs. (1)-(4)
With gamma matrix algebra in exact 4-dimension and translational invariance of integral momentum, the quadratic divergences cancelTransverse condition is satisfied in supersymmetric model with the Feynman gauge ξ = 1
Fermion self-energy diagram Fig. (5)Contribution from Fig. (6)
Contribution from Fig. (7)-(9)
Quadratic divergences cancel automatically due to SUSY without the need of consistency condition for the quadratic ILIs
Ward identity in SUSY gauge model is satisfied with only the need of consistency condition for the logarithmic ILIs in LORE method
Transverse condition or Gauge symmetry can be maintained
In the general ξ gauge, there is a term proportion to
a_0 ≠ 1 will break the transverse condition, only when regularization scheme satisfies consistency condition with
With a_0 being defined via logarithmic divergent
LORE method preserves not only Yang-Mills gauge symmetry, but also supersymmetry
Renormalization of Massive Wess-Zumino Model
The action of massive Wess-Zumino mode
Non-renormalization theorem implies a single renormalization constant(only the first dynamical term in superpotential needs a counterterm)
Renormalizations of fields, mass and coupling constant must satisfy
non-vanishing one-loop divergent graphs
All renormalized vertices do lead to a single renormalization constant
With the counterterms Lagrangian
Resulting renormalization of fields and masses
Gravitational Contributions to Gauge Green’s Functions and Asymptotic Free Power-Law Running of Gauge Coupling
【 1 】 S. P. Robinson and F. Wilczek Phys. Rev. Lett. 96, 231601 (2006) 【 2 】 A. R. Pietrykowski, Phys. Rev. Lett. 98, 061801 (2007).【 3 】 D. J. Toms, Phys. Rev. D 76, 045015 (2007).【 4 】 D. Ebert, J. Plefka and A. Rodigast, Phys. Lett. B660, 579(2008).
Robinson and Wilczek was the first to calculate the gravitational contributions to gauge coupling and show the power-law running in hamornic gauge condition by using cut-off regularization approach
Pietrykowski noticed that RW result is gauge condition dependent;
Toms calculated in DR with using gauge-condition independent formalism based on Vilkovisky-DeWitt’s background field method;
Ebert et al. performed a diagrammatic calculation of two- and three-point Green’s functions in the harmonic gauge by using both cut-off and DR schemes
Conclusion: No power-law running from gravitational contributions
Gravitational Contributions to Gauge Coupling
【 1 】 Y. Tang and Y. L. Wu, Comm. Theo. Phys. 54, 1040(2010), arXiv:0807.0331【 2 】 Y. Tang and Y. L. Wu, Comm. Theor. Phys.57, 629 (2012), arXiv:1012.0626 [hep-ph]
Conclusion I: by checking all the calculations: the results are not only gauge condition dependent but also regularization scheme dependent(DRsuppresses quadratic divergent behavior; Cut-offdoesn’t satisfy consistency condition for gauge invariance) Conclusion II: gravitational contributions lead to asymptotically free power-law running gauge coupling in the harmonic gauge condition when using the LORE method to carry out the same calculations with both the diagrammatic and traditional background-field methods
Gravitational Contributions to Gauge Theories and Asymptotic Free Power-Law Running of Gauge Coupling
Conclusion III: Gauge coupling is power-law running and asymptotically free due to gravitational contributions when using the gauge condition independent Vilkovisky-DeWitt formalism of background field method and consistency condition of quadratic ILIs
J. E. Daum, U. Harst and M. Reuter, JHEP 1001,084(2010). Feng Wu and Ming Zhong, Phys. Lett. B659, 694(2008), Phys. Rev. D
78, 085010 (2008). A. Rodigast and T. Schuster, Phys. Rev. D 79, 125017(2009), Phys. Rev.
Lett. 104, 081301 (2010). O. Zanusso, L. Zambelli, G.P. Vacca and R. Percacci, Phys.Lett. B689,
90(1010). Paul T. Mackay and David J. Toms, Phys. Lett. B684, 251(2010). M. M. Anber, J. F. Donoghue and M. El-Houssieny, Phys. Rev. D83,
124003 (2011). [arXiv:1011.3229 [hep-th]]. E. Gerwick, Eur. Phys. J. C71, 1676 (2011). [arXiv:1012.1118 [hep-ph]]. John Ellis and Nick E. Mavromatos, arXiv:1012:4353 [hep-th]. S. Folkerts, D. F. Litim, J. M. Pawlowski, [arXiv:1101.5552 [hep-th]], D. F.
Litim, [arXiv:1102.4624 [hep-th]]. D. J. Toms, Phys. Rev. Lett. 101, 131301 (2008), Phys. Rev. D 80,
064040(2009). D. J. Toms, Nature 468, 56 (2010).
More other discussions
Vilkovisky-DeWitt Effective Action (Gauge Condition Independent)
Background field Quantum field Faddeev-Popov factor
Gauge condition Gauge invariance Landau-DeWitt gauge condition Effective actions
Application to Gravity-Gauge System
Metric g_ij [φ] on the field space
Landau-DeWitt gauge conditions
Gauge fixed termEffective action
Two fields Background
Total graviton’s contribution to the effective action
Renormalized gauge action
Gravitational correction to the β function
β Function Correction From Gravitational Contributions
Cosmological constantΛeffect
Landau-DeWitt gauge condition
One-loop gravitational contributions concern the tensor-type and scalar-type quadratic divergences, their consistency condition and quadratic divergence behavior are crucial for β function correction
Quadratic divergence behavior Power-Law running
Consistency condition of gauge invariance
Asymptotic free power-law running
In Dimensional RegularizationIn the cut-off regularization
no asymptotic freedomFor an independent check, revisit the traditional
background field method in the harmonic gauge by taking the following parameters
In the cut-off regularizationWith inconsistency conditionWith consistency condition of ILIs or in LORE method
Asymptotic free power-law running
accidental cancellation
No quadratic effects due to DR
Diagrammatical CalculationsCheck of gauge
invariance:Two-point, three-point, four-point Green functions by using the traditional background field method in harmonic gauge condition With Counter termsIn DR & cut-off reg.In LORE methodSatisfy Slavnov-Taylor-Ward identities gauge invariant
The β function
U(1) gauge
Asymptotic free power-law running
Recover the result via traditional background field method calculation
General Conclusion:
Asymptotic Free Power Law Running of Gauge Coupling due to gravitational effects Gauge condition
independent Regularization scheme
independent Y. Tang and Y.L. Wu, JHEP 1111, 073 (2011), arXiv:1109.4001 [hep-ph]
The Consistency of LORE Method with Explicit Calculations at Two-Loop Level
’t Hooft & Veltman: A general two-loop order Feynman diagram can be reduced to the general αβγ integrals
Evaluating General αβγ integral into ILIs:UVDP parametrization get rid of the cross terms of momenta
Treatment of Overlapping Divergence in UVDP Parameter Space
overall divergenceDivergence of subdiagramαγ
Counter part
Treatment of UVDP parameter divergence
overall quadratic divergence
Similar for Circuit 2 and Circuit 3
Application to Two Loop Calculations by LORE in ϕ^4 Theory
Log-running to coupling constant at two loop level
β-function for the renormalized coupling constant λ
Power-law running of mass at two loop level
One loop contribution with quadratic term to the scalar mass by the LORE method
Two loop contribution with quadratic term to the scalar mass by the LORE method
Application to Two Loop Calculations by LORE in ϕ^4 Theory
Consistency of LORE Beyond One Loop
Quantum Structure of Quadratic Divergent
LORE Beyond One Loop
Quadratic term is a harmful divergence, and also breaks underlying gauge invariance and its associated Ward identity.
Quadratic term even combined with their corresponding counterterm insertion diagrams is still a harmful divergence, and also breaks underlying gauge invariance and its associated Ward identity.
Counter part
Two-loop vertex corrections
Quadratic term is a harmful divergence for each diagram
Counter part
Again quadratic term even combined with their corresponding counterterm is still a harmful divergence for each diagram
Sum up over all the relevant diagrams
Quadratic harmful divergences cancel for the final result, recover the gauge invariance and locality
Quadratic divergences are canceled, which is crucial to guarantee that photon does not obtain a mass from quantum fluctuation and that the whole theory remains gauge invariance.
Two loop Harmful divergences like vanish, only when summing up over all relevant loop diagrams, which is expected as these terms are nonlocal and cannot be eliminated by any counter terms in the original Lagrangian which are local.
Quantum Anomaly Based on LORE Method
Triangle Anomaly Amplitudes
Using the definition of gamma_5 Trace of gamma matrices gets the most general
and unique structure with symmetric Lorentz indices
Y.L.Ma & YLW
Anomaly of Axial Current Explicit calculation based on LORE method with the most
general and symmetric Lorentz structure
Restore the original theory in the limit
Vector currents are automatically conserved, only the axial-vector Ward identity is violated by quantum corrections
Chiral Anomaly Based on LORE Method
Including the cross diagram, the final result is
Which leads to the well-known anomaly form
Anomaly Based on Various Regularizations
Using the most general and symmetric trace formula for gamma matrices with gamma_5.
In unit
Loop Regularization (LORE) Method
Trace Anomaly Based on LORE
Naïve dilation Ward identity
Dilation transformation or scaling transformation
Current of dilation transformation & Energy-momentum Tensor
QED Lagrangian
Quantum corrections to the dilation Ward identityVacuum polarization
Consistency condition
Three-point function
With consistency condition
Dilation Ward identity violated by quantum corrections
Dilation Ward identity
Trace anomaly/anomaly Ward identity in operator formalism
Lorentz and CPT Violation in QFT
QFT may not be an underlying theory but EFT
In String Theory, Lorentz invariance can be broken down spontaneously.
Lorentz non-invariant quantum field theory
Explicit 、 Spontaneous 、 Induced CPT/Lorentz violating Chern-Simons term
constant vector
Induced CTP/Lorentz Violation
eQED with constant vector
CPT/Lorentz violating Chern-Simons term
constant vector
mass
What is the relation ?
Diverse Results
Gauge invariance of axial-current S.Coleman and S.L.Glashow, Phys.Rev.D59: 116008 (1999) Pauli-Villas regularization with D.Colladay and V.A.Kostelecky, Phys. Rev. D58:116002 (1998). Gauge invariance and conservation of vector Ward
identity M.Perez-Victoria, JHEP 0104 032 (2001). Consistent analysis via dimensional regularization G.Bonneau, Nucl. Phys. B593 398 (2001).
Diverse Results
Based on nonperturbative formulation with R.Jackiw and V.A.Kostelecky, Phys.Rev.Lett. 82: 3572 (1999). Derivative Expansion with dimensional regularization J.M.Chung and P.Oh, Phys.Rev.D60: 067702 (1999). Keep full dependence with M.Perez-Victoria, Phys.Rev.Lett.83: 2518 (1999).
Keep full dependence with M.Perez-Victoria, Phys.Rev.Lett.83: 2518 (1999).
Consistent Result Statement in Literature: constant vector K
can only be determined by experiment Our Conclusion: constant vector K can
consistently be fixed from theoretical calculations
Regularization Scheme Regularization scheme dependence Ambiguity of Dimensional regularization
with problem
Ambiguity with momentum translation for linear divergent term Ambiguity of reducing triangle diagrams
Explicit Calculation Based on LORE Method
Amplitudes of triangle diagrams
Contributions to Amplitudes
Convergent contributions
Divergent contributions
Logarithmic DV Linear DV
Contributions to Amplitudes
Logarithmic Divergent Contributions
Regularized result with LORE
Contributions to Amplitudes
Linear divergent contributions
Regularized result
Contributions to Amplitudes
Total contributions arise from convergent part
Final Result Setting
Final result is
Induced Chern-Simons term is uniqely determined when combining the chiral anomalyThere is no harmful induced Chern-Simons term for massive fermions.
Comments on Ambiguity
Momentum translation relation of linear divergent
Make Regularization after using the relation
Check on Consistency
Ambiguity of results
Inconsistency with U(1) chiral anomaly of
Must applying for the regularization before using momentum translation relation of linear divergent integral
Dynamically Generated Spontaneous Symmetry Breaking of QCD
Based on LORE Method
QCD Lagrangian and SymmetryQCD Lagrangian of light quarks
Effective Lagrangian Based on LORE Method
Y.B. Dai and Y-L. Wu, Euro. Phys. J. C 39 s1 (2004)
Integrating out quark fields by using the LORE method
Dynamically Generated Spontaneous Symmetry Breaking
Quadratic Term by the LORE method
Composite Higgs Potential
Dynamically Generated Spontaneous Symmetry Breaking
M_c meaningful characterizing energy scale
Scalars as Partner of Pseudoscalars & The Lightest Composite Higgs Bosons
Scalar mesons:
Pseudoscalar mesons :
Mass Formula Pseudoscalar mesons :
Mass Formula
Predictions for Mass Spectra & Mixings
M_c ~ 1 GeV Nonperturbative energy scale
μ_s ~ 300 MeV QCD energy scale
Predictions
QCD Phase Transition with Chiral Symmetry Restoration
Based on LORE Method
Consider two flavor without instanton effects
After integrating out quark fields
Carrying out momentum integration by the LORE method
Applying the Schwinger Closed-Time-Path Green Function (CTPGF) Formalism to the Quark Propagators
The propagator of quark fields
Effective Lagrangian of Chiral Thermodynamic Model of QCD at the lowest order with Finite Temperature
Both logarithmic and quadratic integrals depend on Temperature by LORE method
Dynamically generated effective composite Higgs potential of mesons at finite temperature based on LORE Method
Thermodynamic Gap Equation
Assumption: The scale of NJL four quark interaction due to NP QCD has the same T-dependence as quark condensate
Critical temperature for Chiral Symmetry Restoration at
Critical temperature is given by the Quadratic Term in the LORE method
T Tc
Input Parameters
Output Predictions
Critical Temperature of chiral symmetry restoration
Thermodynamic Behavior of Physical Quantities
Thermodynamic VEV
Thermodynamic Behavior of Physical Quantities
CONCLUSIONS The LORE method is a kind of infinity-free
and symmetry-preserving regularization scheme
The LORE method introduces two intrinsic energy scales M_c & μ_s which become physically meaningful to play the role as the characterizing energy scale M_c and sliding energy scales μ_s
The LORE method realized in exact dimension of original theory is applicable to the underlying, effective, supersymmetric and chiral QFTs
The LORE method with the consistency conditions can give the sensible results which satisfy all the requirements: gauge invariance and locality.
The LORE method only requires the use of consistency conditions at one-loop level and does not need to introduce additional higher order consistency conditions.
The concept of ILIs and the electric circuit analogy of Feynman diagrams enable us to apply the LORE method to all order by a diagramatic way
CONCLUSIONS
Quantum structure of quadratic term is crucial to understand symmetry and symmetry breaking
Proper treatment of quadratic divergence is important to understand the quantum structure of QFTs
Quantization of gravity is the key to understand eventually the unification of forces and the darkness of universe
CONCLUSIONS
THANKS