ELECTROWEAK GAUGE ANOMALY AND THE NEW PHYSICS SCALE

1992 ◽  
Vol 07 (20) ◽  
pp. 1791-1797
Author(s):  
KEIICHI AKAMA ◽  
TAKASHI HATTORI
Keyword(s):  
Gauge Theory ◽  
Upper Bound ◽  
Gauge Theories ◽  
New Physics ◽  
Experimental Results ◽  
Gauge Anomaly

It is argued that chiral anomalies in the effective gauge theories are allowed, as far as the new physics scale is not too large. We estimate the anomaly-induced masses of the weak bosons, when the anomalies exist in the electroweak gauge theory, and compare them with the experimental results to extract the upper bound on the new-physics scale.

Ward–Takahashi identities for Abelian chiral gauge theories

2016 ◽  
Vol 31 (11) ◽  
pp. 1650062
Author(s):  
Ana Paula Cardoso Rodrigues de Lima ◽  
Sebastião Alves Dias
Keyword(s):  
Gauge Theory ◽  
Future Study ◽  
Gauge Theories ◽  
Charge Renormalization ◽  
Renormalization Constants ◽  
Gauge Anomaly

By considering a general Abelian chiral gauge theory, we investigate the behavior of anomalous Ward–Takahashi (WT) identities concerning their prediction for the usual relationship between the vertex and two-point fermion functions. Using gauge anomaly vanishing results, we show that the usual (in the nonanomalous case) WT identity connecting the vertex and two-point fermion 1PI functions is modified for Abelian chiral gauge theories. The modification, however, implies a relation between fermion and charge renormalization constants that can be important in a future study of renormalization of such theories.

scholarly journals On Gauge Invariance of the Bosonic Measure in Chiral Gauge Theories

Universe ◽  
2021 ◽  
Vol 7 (8) ◽  
pp. 283
Author(s):  
Gabriel de Lima e Silva ◽  
Thalis José Girardi ◽  
Sebastião Alves Dias
Keyword(s):  
Hilbert Space ◽  
Gauge Theory ◽  
Path Integral ◽  
Gauge Invariance ◽  
Gauge Theories ◽  
Direct Calculation ◽  
Identity Operator ◽  
Anomaly Cancellation ◽  
Gauge Anomaly ◽  
General Gauge

Gauge invariance of the measure associated with the gauge field is usually taken for granted, in a general gauge theory. We furnish a proof of this invariance, within Fujikawa’s approach. To stress the importance of this fact, we briefly review gauge anomaly cancellation as a consequence of gauge invariance of the bosonic measure and compare this cancellation to usual results from algebraic renormalization, showing that there are no potential inconsistencies. Then, using a path integral argument, we show that a possible Jacobian for the gauge transformation has to be the identity operator, in the physical Hilbert space. We extend the argument to the complete Hilbert space by a direct calculation.

scholarly journals The Volume of the Quiver Vortex Moduli Space

2021 ◽  
Author(s):  
Kazutoshi Ohta ◽  
Norisuke Sakai
Keyword(s):  
Gauge Theory ◽  
Moduli Space ◽  
Riemann Surfaces ◽  
Gauge Theories ◽  
Target Space ◽  
Contour Integral ◽  
Quiver Gauge Theory ◽  
Volume Formula ◽  
Volume Operator ◽  
Space Volume

Abstract We study the moduli space volume of BPS vortices in quiver gauge theories on compact Riemann surfaces. The existence of BPS vortices imposes constraints on the quiver gauge theories. We show that the moduli space volume is given by a vev of a suitable cohomological operator (volume operator) in a supersymmetric quiver gauge theory, where BPS equations of the vortices are embedded. In the supersymmetric gauge theory, the moduli space volume is exactly evaluated as a contour integral by using the localization. Graph theory is useful to construct the supersymmetric quiver gauge theory and to derive the volume formula. The contour integral formula of the volume (generalization of the Jeffrey-Kirwan residue formula) leads to the Bradlow bounds (upper bounds on the vorticity by the area of the Riemann surface divided by the intrinsic size of the vortex). We give some examples of various quiver gauge theories and discuss properties of the moduli space volume in these theories. Our formula are applied to the volume of the vortex moduli space in the gauged non-linear sigma model with CPN target space, which is obtained by a strong coupling limit of a parent quiver gauge theory. We also discuss a non-Abelian generalization of the quiver gauge theory and “Abelianization” of the volume formula.

scholarly journals NEW PHYSICS UPPER BOUND ON THE BRANCHING RATIO OF Bs → l+l-γ

2007 ◽  
Vol 22 (18) ◽  
pp. 1319-1328 ◽  
Author(s):  
ASHUTOSH KUMAR ALOK ◽  
S. UMA SANKAR
Keyword(s):  
Upper Bound ◽  
Axial Vector ◽  
Branching Ratio ◽  
New Physics ◽  
Large Contribution ◽  
Beyond The Standard Model ◽  
Standard Model Expectation ◽  
Model Expectation ◽  
The Standard Model ◽  
Large Enhancement

We consider the effect of new physics on the branching ratio of Bs → l+l-γ where l = e, μ. If the new physics is of the form scalar/pseudoscalar, then it makes no contribution to Bs → l+l-γ, unlike in the case of Bs → l+l-, where it can potentially make a very large contribution. If the new physics is in the form of vector/axial-vector operators, then the present data on B → (K, K*) l+l- does not allow a large enhancement for B(Bs → l+l- γ). If the new physics is in the form of tensor/pseudotensor operators, then the data on B → (K, K*) l+l- gives no useful constraint but the data on B → K* γ does. Here again, a large enhancement of B(Bs → l+l-γ), much beyond the Standard Model expectation, is not possible. Hence, we conclude that the present data on b → s transitions allow a large boost in B(Bs → l+l-) but not in B(Bs → l+l-γ).

scholarly journals Displaced new physics at colliders and the early universe before its first second

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Lorenzo Calibbi ◽  
Francesco D’Eramo ◽  
Sam Junius ◽  
Laura Lopez-Honorez ◽  
Alberto Mariotti
Keyword(s):  
Dark Matter ◽  
Early Universe ◽  
Upper Bound ◽  
New Physics ◽  
Early History ◽  
Relic Density ◽  
History Of ◽  
Indirect Information ◽  
The Universe

Abstract Displaced vertices at colliders, arising from the production and decay of long-lived particles, probe dark matter candidates produced via freeze-in. If one assumes a standard cosmological history, these decays happen inside the detector only if the dark matter is very light because of the relic density constraint. Here, we argue how displaced events could very well point to freeze-in within a non-standard early universe history. Focusing on the cosmology of inflationary reheating, we explore the interplay between the reheating temperature and collider signatures for minimal freeze-in scenarios. Observing displaced events at the LHC would allow to set an upper bound on the reheating temperature and, in general, to gather indirect information on the early history of the universe.

scholarly journals META-STABLE BRANE CONFIGURATIONS WITH MULTIPLE NS5-BRANES

2009 ◽  
Vol 24 (27) ◽  
pp. 5051-5120
Author(s):  
CHANGHYUN AHN
Keyword(s):  
Gauge Theory ◽  
String Theory ◽  
Gauge Group ◽  
Gauge Theories ◽  
The Other ◽  
Multiple Product

Starting from an [Formula: see text] supersymmetric electric gauge theory with the multiple product gauge group and the bifundamentals, we apply Seiberg dual to each gauge group, obtain the [Formula: see text] supersymmetric dual magnetic gauge theories with dual matters including the gauge singlets. Then we describe the intersecting brane configurations, where there are NS-branes and D4-branes (and anti-D4-branes), of type IIA string theory corresponding to the meta-stable nonsupersymmetric vacua of this gauge theory. We also discuss the case where the orientifold 4-planes are added into the above brane configuration. Next, by adding an orientifold 6-plane, we apply to an [Formula: see text] supersymmetric electric gauge theory with the multiple product gauge group (where a single symplectic or orthogonal gauge group is present) and the bifundamentals. Finally, we describe the other cases where the orientifold 6-plane intersects with NS-brane.

scholarly journals HAMILTONIAN COHOMOLOGICAL DERIVATION OF FOUR-DIMENSIONAL NONLINEAR GAUGE THEORIES

2002 ◽  
Vol 17 (16) ◽  
pp. 2191-2210 ◽  
Author(s):  
C. BIZDADEA ◽  
E. M. CIOROIANU ◽  
S. O. SALIU
Keyword(s):  
Gauge Theory ◽  
Gauge Theories ◽  
Scalar Fields ◽  
Gauge Algebra ◽  
Brst Cohomology ◽  
Nonlinear Gauge

Consistent couplings among a set of scalar fields, two types of one-forms and a system of two-forms are investigated in the light of the Hamiltonian BRST cohomology, giving a four-dimensional nonlinear gauge theory. The emerging interactions deform the first-class constraints, the Hamiltonian gauge algebra, as well as the reducibility relations.

SUPERSYMMETRIC TENSOR GAUGE THEORIES

1989 ◽  
Vol 04 (14) ◽  
pp. 1343-1353 ◽  
Author(s):  
T.E. CLARK ◽  
C.-H. LEE ◽  
S.T. LOVE
Keyword(s):  
Gauge Theory ◽  
Gauge Symmetry ◽  
Sigma Models ◽  
Gauge Field ◽  
Gauge Theories ◽  
Symmetric Tensor ◽  
Global Symmetry ◽  
Invariant Action ◽  
Symmetry Transformations ◽  
Linear Sigma Models

The supersymmetric extensions of anti-symmetric tensor gauge theories and their associated tensor gauge symmetry transformations are constructed. The classical equivalence between such supersymmetric tensor gauge theories and supersymmetric non-linear sigma models is established. The global symmetry of the supersymmetric tensor gauge theory is gauged and the locally invariant action is obtained. The supercurrent on the Kähler manifold is found in terms of the supersymmetric tensor gauge field.

scholarly journals Review of strongly-coupled composite dark matter models and lattice simulations

2016 ◽  
Vol 31 (22) ◽  
pp. 1643004 ◽  
Author(s):  
Graham D. Kribs ◽  
Ethan T. Neil
Keyword(s):  
Dark Matter ◽  
Gauge Theory ◽  
Direct Detection ◽  
Bound State ◽  
New Physics ◽  
Abelian Gauge ◽  
Strongly Coupled ◽  
Abelian Gauge Theory ◽  
Lattice Calculations ◽  
Composite Description

We review models of new physics in which dark matter arises as a composite bound state from a confining strongly-coupled non-Abelian gauge theory. We discuss several qualitatively distinct classes of composite candidates, including dark mesons, dark baryons, and dark glueballs. We highlight some of the promising strategies for direct detection, especially through dark moments, using the symmetries and properties of the composite description to identify the operators that dominate the interactions of dark matter with matter, as well as dark matter self-interactions. We briefly discuss the implications of these theories at colliders, especially the (potentially novel) phenomenology of dark mesons in various regimes of the models. Throughout the review, we highlight the use of lattice calculations in the study of these strongly-coupled theories, to obtain precise quantitative predictions and new insights into the dynamics.

Study of the semileptonic Bc → ηcτ−v̄τ decay in W′ model

2021 ◽  
Author(s):  
S. Mahata ◽  
P. Maji ◽  
S. Biswas ◽  
S. Sahoo
Keyword(s):  
Standard Model ◽  
Branching Ratio ◽  
New Physics ◽  
Experimental Results ◽  
Lepton Flavor ◽  
The Standard Model ◽  
Text Model

Recently, many discrepancies between the Standard Model (SM) predictions and experimental results have been found in [Formula: see text] quark transitions. Motivated by these discrepancies, we investigated the semileptonic [Formula: see text] decay in [Formula: see text] model. In this paper, we have estimated different decay observables such as branching ratio, lepton flavor universality (LFU) ratio [Formula: see text] and forward–backward asymmetry in the SM as well as in the [Formula: see text] model. In [Formula: see text] model, we find significant deviations from the SM for the observables except for the forward–backward asymmetry. This deviation gives us a possible indication of new physics (NP).

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