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We discuss chiral theories of constituent quarks interacting with bosons at high temperatures. In the chirally symmetric phase we demonstrate by applying functional methods the presence of effective anomalous couplings for e.g. $\pi \sigma…

High Energy Physics - Phenomenology · Physics 2009-10-28 R. Baier , M. Dirks , O. Kober

Using constituent quarks coupled to a linear sigma model at nonzero temperature, I show that many anomalous mesonic amplitudes, such as $\pi^0 \rightarrow \gamma \gamma$, vanish in a chirally symmetric phase. Processes which are allowed,…

High Energy Physics - Phenomenology · Physics 2014-11-17 Robert D. Pisarski

Thermal behavior of effective, chiral condensate-dependent $U_A(1)$ anomaly couplings is investigated using the functional renormalization group approach in the $N_f = 3$ flavor meson model. We derive flow equations for anomaly couplings…

High Energy Physics - Phenomenology · Physics 2024-02-29 G. Fejos , A. Patkos

The temperature dependence of the anomalous sector of the effective action of fermions coupled to external gauge and pseudo-scalar fields is computed at leading order in an expansion in the number of Lorentz indices in two and four…

High Energy Physics - Theory · Physics 2016-08-25 L. L. Salcedo

The photon self-energy from chirally imbalanced quark matter is evaluated at finite temperature and density using the real time formulation of thermal field theory. The analytic structure is explored in detail exposing the cut structure…

High Energy Physics - Phenomenology · Physics 2022-05-05 Snigdha Ghosh , Nilanjan Chaudhuri , Sourav Sarkar , Pradip Roy

We describe our recent proposal that distinct phases of gauge theories with fundamental quarks translate into specific types of low-energy behavior in Dirac spectral density. The resulting scenario is built around new evidence…

High Energy Physics - Lattice · Physics 2015-12-01 Andrei Alexandru , Ivan Horváth

Chiral perturbation theory in the anomaly sector for $N_f=2$ is extended to include dynamical photons, thereby allowing a complete treatment of isospin breaking. A minimal set of independent chiral lagrangian terms is determined and the…

High Energy Physics - Phenomenology · Physics 2014-11-17 B. Ananthanarayan , B. Moussallam

Anomalous moments of the top quark arises from one loop corrections to the vertices $\bar t t g$ and $\bar t t \gamma$. We study these anomalous couplings in different frameworks: effective theories, Standard Model and 2HDM. We use…

High Energy Physics - Phenomenology · Physics 2014-11-17 R. Martinez , N. Poveda , J. -Alexis Rodriguez

This dissertation studies the quantum anomalous effects on the description of high energy electrodynamics. We argue that on the temperatures comparable to the electroweak scale, characteristic for the early Universe and objects like neutron…

High Energy Physics - Phenomenology · Physics 2021-02-23 Petar Pavlović

We consider the electroweak production of a top quark in association with a photon at the LHC to probe the electroweak top quark couplings (t$\bar{\text{t}}\gamma$) as well as the triple gauge boson couplings (WW$\gamma$). The study is…

High Energy Physics - Phenomenology · Physics 2016-10-05 Seyed Mohsen Etesami , Sara Khatibi , Mojtaba Mohammadi Najafabadi

The amplitude for the anomalous transitions gamma pi(+) -> pi(0) pi(+) is analyzed within Chiral Perturbation Theory including electromagnetic interactions. The presence of a t-channel one-photon exchange contribution induces sizeable e^2…

High Energy Physics - Phenomenology · Physics 2009-11-07 Ll. Ametller , M. Knecht , P. Talavera

The amplitude for the anomalous process gamma pi -> pi pi is evaluated to two loops in the chiral expansion by means of a dispersive method. The two new coupling constants that enter at this order are estimated via sum rules derived from a…

High Energy Physics - Phenomenology · Physics 2009-11-07 Torben Hannah

The chiral plasmon modes of relativistic matter in background magnetic and strain-induced pseudomagnetic fields are studied in detail using the consistent chiral kinetic theory. The results reveal a number of anomalous features of these…

Mesoscale and Nanoscale Physics · Physics 2017-03-27 E. V. Gorbar , V. A. Miransky , I. A. Shovkovy , P. O. Sukhachov

We compute the effects of anomalous gauge-boson couplings at high-energy hadron colliders using next-to-leading order $SU(2) \times SU(2)$ chiral perturbation theory. By comparing the yields from the universal $p^2$ terms with those arising…

High Energy Physics - Phenomenology · Physics 2009-10-22 J. Bagger , S. Dawson , G. Valencia

The dimension-four genuine anomalous quartic couplings are studied in processes of six-fermion production via e+e- collisions. Complete tree-level electroweak calculations are performed including initial-state-radiation and beamstrahlung.…

High Energy Physics - Phenomenology · Physics 2007-05-23 Fabrizio Gangemi

Photon-photon reaction provides an excellent opportunity to isolate the $tq\gamma$ vertex. For this purpose, we have examined the potential of the $e^{-}e^{+}\rightarrow e^{-}\gamma^{*}\gamma^{*}e^{+}\rightarrow…

High Energy Physics - Phenomenology · Physics 2014-06-03 A. A. Billur , M. Koksal

We study the nature of the chiral transition for an effective theory with spontaneous breaking of symmetry, where charged bosons and fermions are subject to the effects of a constant external magnetic field. The problem is studied in terms…

High Energy Physics - Phenomenology · Physics 2014-07-02 Alejandro Ayala , Luis Alberto Hernandez , Ana Julia Mizher , Juan Cristobal Rojas , Cristian Villavicencio

Search for new-physics through possible anomalous t tbar gamma, tbW and gamma gamma H couplings which are generated by SU(2) X U(1) gauge-invariant dimension-6 effective operators is discussed, using energy and angular distributions of…

High Energy Physics - Phenomenology · Physics 2007-05-23 Bohdan Grzadkowski , Zenro Hioki , Kazumasa Ohkuma , Jose Wudka

A study on effective anomalous interactions up to dimension 5 of the top quark with the electroweak gauge bosons is made in the non-linear Chiral Lagrangian approach. Bounds on the anomalous dimension four terms are obtained from their…

High Energy Physics - Phenomenology · Physics 2014-11-17 F. Larios , Ehab Malkawi , C. -P. Yuan

We investigate the possible restoration of chiral and axial symmetries across the phase transition at finite temperature and chemical potential, by analyzing the behavior of several physics quantities, such as the quark condensates and the…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. C. Ruivo , Pedro Costa , C. A. de Sousa
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