scholarly journals Non-Abelian axial anomaly, axial-vector duality, and the pseudoscalar glueball

2021 ◽  
Vol 104 (1) ◽  
Author(s):  
Sergey Khlebtsov ◽  
Yaroslav Klopot ◽  
Armen Oganesian ◽  
Oleg Teryaev
Keyword(s):  
2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Taushif Ahmed ◽  
Long Chen ◽  
Michał Czakon

Abstract The renormalization constant ZJ of the flavor-singlet axial-vector current with a non-anticommuting γ5 in dimensional regularization is determined to order $$ {\alpha}_s^3 $$ α s 3 in QCD with massless quarks. The result is obtained by computing the matrix elements of the operators appearing in the axial-anomaly equation $$ {\left[{\partial}_{\mu }{J}_5^{\mu}\right]}_R=\frac{\alpha_s}{4\pi }{n}_f{\mathrm{T}}_F{\left[F\tilde{F}\right]}_R $$ ∂ μ J 5 μ R = α s 4 π n f T F F F ˜ R between the vacuum and a state of two (off-shell) gluons to 4-loop order. Furthermore, through this computation, the equality between the $$ \overline{\mathrm{MS}} $$ MS ¯ renormalization constant $$ {Z}_{F\tilde{F}} $$ Z F F ˜ associated with the operator $$ {\left[F\tilde{F}\right]}_R $$ F F ˜ R and that of αs is verified explicitly to hold true at 4-loop order. This equality automatically ensures a relation between the respective anomalous dimensions, $$ {\gamma}_J=\frac{\alpha_s}{4\pi }{n}_f{\mathrm{T}}_F{\gamma}_{FJ} $$ γ J = α s 4 π n f T F γ FJ , at order $$ {\alpha}_s^4 $$ α s 4 given the validity of the axial-anomaly equation which was used to determine the non-$$ \overline{\mathrm{MS}} $$ MS ¯ piece of ZJ for the particular γ5 prescription in use.


2003 ◽  
Vol 81 (12) ◽  
pp. 1343-1347
Author(s):  
M P Gagné-Portelance ◽  
D.G.C. McKeon

We consider one-loop divergences in a four-dimensional model in which a non-Abelian vector field has an axial vector coupling with a massless left-handed spinor field. This is done by computing the diagonal element of the second Seeley–deWitt coefficient a2(x,x). Even when the coupling is such that the axial anomaly vanishes, divergences arise that are not gauge invariant. Operator regularization is used throughout so as to leave the matrix γ5 unambiguously defined. PACS No.: 11.15.q


1993 ◽  
Vol 48 (10) ◽  
pp. 4916-4918
Author(s):  
Dae Sung Hwang ◽  
Chang-Yeong Lee

2021 ◽  
Vol 966 ◽  
pp. 115385
Author(s):  
Emil Mottola ◽  
Andrey V. Sadofyev
Keyword(s):  

2021 ◽  
Vol 126 (21) ◽  
Author(s):  
Yu. M. Andreev ◽  
D. Banerjee ◽  
J. Bernhard ◽  
V. E. Burtsev ◽  
A. G. Chumakov ◽  
...  

2020 ◽  
Vol 2020 (11) ◽  
Author(s):  
Sebastian A. R. Ellis ◽  
Jérémie Quevillon ◽  
Pham Ngoc Hoa Vuong ◽  
Tevong You ◽  
Zhengkang Zhang

Abstract Recent development of path integral matching techniques based on the covariant derivative expansion has made manifest a universal structure of one-loop effective Lagrangians. The universal terms can be computed once and for all to serve as a reference for one-loop matching calculations and to ease their automation. Here we present the fermionic universal one-loop effective action (UOLEA), resulting from integrating out heavy fermions (Dirac or Majorana) with scalar, pseudo-scalar, vector and axial-vector couplings. We also clarify the relation of the new terms computed here to terms previously computed in the literature and those that remain to complete the UOLEA. Our results can be readily used to efficiently obtain analytical expressions for effective operators arising from heavy fermion loops [13].


2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
G. Aad ◽  
◽  
B. Abbott ◽  
D. C. Abbott ◽  
A. Abed Abud ◽  
...  

Abstract A search for dark matter is conducted in final states containing a photon and missing transverse momentum in proton-proton collisions at $$ \sqrt{s} $$ s = 13 TeV. The data, collected during 2015–2018 by the ATLAS experiment at the CERN LHC, correspond to an integrated luminosity of 139 fb−1. No deviations from the predictions of the Standard Model are observed and 95% confidence-level upper limits between 2.45 fb and 0.5 fb are set on the visible cross section for contributions from physics beyond the Standard Model, in different ranges of the missing transverse momentum. The results are interpreted as 95% confidence-level limits in models where weakly interacting dark-matter candidates are pair-produced via an s-channel axial-vector or vector mediator. Dark-matter candidates with masses up to 415 (580) GeV are excluded for axial-vector (vector) mediators, while the maximum excluded mass of the mediator is 1460 (1470) GeV. In addition, the results are expressed in terms of 95% confidence-level limits on the parameters of a model with an axion-like particle produced in association with a photon, and are used to constrain the coupling gaZγ of an axion-like particle to the electroweak gauge bosons.


2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Petr Beneš ◽  
Jiří Hošek ◽  
Adam Smetana

Abstract Higgs sector of the Standard model (SM) is replaced by quantum flavor dynamics (QFD), the gauged flavor SU(3)f symmetry with scale Λ. Anomaly freedom requires addition of three νR. The approximate QFD Schwinger-Dyson equation for the Euclidean infrared fermion self-energies Σf(p2) has the spontaneous-chiral-symmetry-breaking solutions ideal for seesaw: (1) Σf(p2) = $$ {M}_{fR}^2/p $$ M fR 2 / p where three Majorana masses MfR of νfR are of order Λ. (2) Σf(p2) = $$ {m}_f^2/p $$ m f 2 / p where three Dirac masses mf = m(0)1 + m(3)λ3 + m(8)λ8 of SM fermions are exponentially suppressed w.r.t. Λ, and degenerate for all SM fermions in f. (1) MfR break SU(3)f symmetry completely; m(3), m(8) superimpose the tiny breaking to U(1) × U(1). All flavor gluons thus acquire self-consistently the masses ∼ Λ. (2) All mf break the electroweak SU(2)L × U(1)Y to U(1)em. Symmetry partners of the composite Nambu-Goldstone bosons are the genuine Higgs particles: (1) three νR-composed Higgses χi with masses ∼ Λ. (2) Two new SM-fermion-composed Higgses h3, h8 with masses ∼ m(3), m(8), respectively. (3) The SM-like SM-fermion-composed Higgs h with mass ∼ m(0), the effective Fermi scale. Σf(p2)-dependent vertices in the electroweak Ward-Takahashi identities imply: the axial-vector ones give rise to the W and Z masses at Fermi scale. The polar-vector ones give rise to the fermion mass splitting in f. At the present exploratory stage the splitting comes out unrealistic.


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