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Related papers: Half-Differentials and Fermion Propagators

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This article deals with two main topics. One is odd parity trace anomalies in Weyl fermion theories in a 4d curved background, the second is the introduction of axial gravity. The motivation for reconsidering the former is to clarify the…

High Energy Physics - Theory · Physics 2017-09-13 L. Bonora , M. Cvitan , P. Dominis Prester , A. Duarte Pereira , S. Giaccari , T. Stemberga

Noticing that really the fermions of the Standard Model are best thought of as Weyl - rather than Dirac - particles (relative to fundamental scales located at some presumably very high energies) it becomes interesting that the experimental…

High Energy Physics - Theory · Physics 2009-09-25 Holger Bech Nielsen , Svend Erik Rugh

Requiring covariance of Maxwell's equations without {\it a priori} imposing charge invariance allows for both spin-1 and spin-1/2 transformations of the complete Maxwell field and current. The spin-1/2 case yields new transformation rules,…

High Energy Physics - Theory · Physics 2008-11-26 Rollin S. Armour

Scale evolution of interactions between a Weyl fermion and a heavy magnetic impurity is calculated non-perturbatively using the functional renormalization group technique. Using an expansion around the vanishing pairing gap, we derive the…

High Energy Physics - Phenomenology · Physics 2023-10-27 Gergely Fejős , Taro Kimura , Zsolt Szép

We consider the scattering of fermions off antifermions with spin 1/2 and 3/2. Starting from helicity partial-wave scattering amplitudes we derive transformations that eliminate all kinematical constraints. Such amplitudes are expected to…

High Energy Physics - Phenomenology · Physics 2015-05-28 S. Stoica , M. F. M. Lutz , O. Scholten

The fermion doubling theorem plays a pivotal role in Hermitian topological materials. It states, for example, that Weyl points must come in pairs in three-dimensional semimetals. Here, we present an extension of the doubling theorem to…

Mesoscale and Nanoscale Physics · Physics 2021-03-03 Zhesen Yang , A. P. Schnyder , Jiangping Hu , Ching-Kai Chiu

We show that the spin (1/2-) particle from the (1/2,1)+(1,1/2) Lorentz irreducible sector of the four-vector spinor can not be described within a linear formalism but behaves as a genuinely quadratic fermion satisfying the generalized…

High Energy Physics - Phenomenology · Physics 2015-07-15 E. G. Delgado Acosta , V. M. Banda Guzmán , M. Kirchbach

In the Majorana representation of a spin 1/2 we find an identity which relates spin-spin correlators to one-particle fermionic correlators. This should be contrasted with the straightforward approach in which two-particle (four-fermion)…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Alexander Shnirman , Yuriy Makhlin

Topological heavy-fermion systems in three dimensions are usually classified as topological insulators or semimetals. Here, we theoretically predict a different type of heavy-fermion system (dubbed exceptional heavy-fermion semimetal) by…

Strongly Correlated Electrons · Physics 2023-02-01 Yu-Liang Tao , Tao Qin , Yong Xu

We give a brief overview of the kinetic theory for spin-1/2 fermions in Wigner function formulism. The chiral and spin kinetic equations can be derived from equations for Wigner functions. A general Wigner function has 16 components which…

High Energy Physics - Phenomenology · Physics 2021-02-03 Jian-Hua Gao , Zuo-Tang Liang , Qun Wang

Weyl semimetals are examples of a new class of topological states of matter which are gapless in the bulk with protected surface states. Their low energy sector is characterized by massless chiral fermions which are robust against…

Strongly Correlated Electrons · Physics 2015-06-22 Michael Phillips , Vivek Aji

Weyl semimetals (WSMs) are characterized by topologically stable pairs of nodal points in the band structure, that typically originate from splitting a degenerate Dirac point by breaking symmetries such as time reversal or inversion…

Strongly Correlated Electrons · Physics 2020-01-29 L. Crippa , A. Amaricci , N. Wagner , G. Sangiovanni , J. C. Budich , M. Capone

We introduce a phase space with spinorial momenta, corresponding to fermionic derivatives, for a 2d supersymmetric (1, 1) sigma model. We show that there is a generalisation of the covariant De Donder-Weyl Hamiltonian formulation on this…

High Energy Physics - Theory · Physics 2020-04-03 Ulf Lindström

We study the transition form factors between pseudoscalar and vector mesons using a covariant fermion field theory model in $(3+1)$ dimensions. Performing the light-front calculation in the $q^+ =0$ frame in parallel with the manifestly…

High Energy Physics - Phenomenology · Physics 2009-11-10 Bernard L. G. Bakker , Ho-Meoyng Choi , Chueng-Ryong Ji

We introduce prepotentials for fermionic higher-spin gauge fields in four spacetime dimensions, generalizing earlier work on bosonic fields. To that end, we first develop tools for handling conformal fermionic higher-spin gauge fields in…

High Energy Physics - Theory · Physics 2018-12-05 Marc Henneaux , Victor Lekeu , Amaury Leonard , Javier Matulich , Stefan Prohazka

In quantum field theory, we learn that fermions come in three varieties: Majorana, Weyl, and Dirac. Here we show that in solid state systems this classification is incomplete and find several additional types of crystal symmetry-protected…

Mesoscale and Nanoscale Physics · Physics 2016-07-25 Barry Bradlyn , Jennifer Cano , Zhijun Wang , M. G. Vergniory , C. Felser , R. J. Cava , B. Andrei Bernevig

In this letter we apply the methods of our previous paper hep-th/0108045 to noncommutative fermions. We show that the fermions form a spin-1/2 representation of the Lorentz algebra. The covariant splitting of the conformal transformations…

High Energy Physics - Theory · Physics 2011-09-13 J. M. Grimstrup , H. Grosse , E. Kraus , L. Popp , M. Schweda , R. Wulkenhaar

Magnetic Weyl semimetals (WSM) have recently attracted much attention due to their potential in realizing strong anomalous Hall effects. Yet, how to design such systems remains unclear. Based on first-principles calculations, we show here…

Materials Science · Physics 2025-02-21 Xiaosong Bai , Yan Wang , Wenwen Yang , Qiunan Xu , Wenjian Liu

We extend our new approach for numeric evaluation of Feynman diagrams to integrals that include fermionic and vector propagators. In this initial discussion we begin by deriving the Sinc function representation for the propagators of…

High Energy Physics - Phenomenology · Physics 2009-10-31 Dmitri Petrov , Richard Easther , Gerald Guralnik , Stephen Hahn , Wei-Mun Wang

Helicons are transverse electromagnetic waves propagating in three-dimensional (3D) electron systems subject to a static magnetic field. We present a theory of helicons propagating through a 3D Weyl semimetal. Our approach relies on the…

Mesoscale and Nanoscale Physics · Physics 2015-11-18 Francesco M. D. Pellegrino , Mikhail I. Katsnelson , Marco Polini