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Three hard problems! In this talk I investigate the long-distance properties of quantum chromodynamics in the presence of a topological theta term. This is done on the lattice, using the gradient flow to isolate the long-distance modes in…

High Energy Physics - Lattice · Physics 2022-02-01 Gerrit Schierholz

As it was suggested by previous works on a modified perturbation expansion for QCD, the possibility for the generation of large quark condensates in the mass-less version of the theory is explored. For this purpose, it is firstly presented…

High Energy Physics - Phenomenology · Physics 2007-05-23 Alejandro Cabo Montes de Oca , Danny Martinez-Pedrera

We propose a novel solution to the Strong CP problem -- to explain why SU(3) strong force has a nearly zero theta angle $\bar\theta_3 \simeq 0$ for the 4d Standard Model (SM). The new ingredient is Symmetric Mass Generation (SMG):…

High Energy Physics - Phenomenology · Physics 2023-01-20 Juven Wang

We describe the effects of the strange quark mass and of the color and electric neutrality on the superconducing phases of QCD.

High Energy Physics - Phenomenology · Physics 2007-05-23 R. Casalbuoni

Since the incident nuclei in heavy-ion collisions do not carry strangeness, the global net strangeness of the detected hadrons has to vanish. We investigate the impact of strangeness neutrality on the phase structure and thermodynamics of…

High Energy Physics - Phenomenology · Physics 2020-04-03 Wei-jie Fu , Jan M. Pawlowski , Fabian Rennecke

We review the recent developments on axion physics. Some new comments on the strong CP problem, the axion mass, and the simple energy loss mechanism of white dwarfs and related issues are included.

High Energy Physics - Phenomenology · Physics 2015-05-14 Jihn E. Kim

We study lattice QCD in the limit that the quark mass and chemical potential are simultaneously made large, resulting in a controllable density of quarks which do not move. This is similar in spirit to the quenched approximation for zero…

High Energy Physics - Lattice · Physics 2009-10-28 Thomas C. Blum , James E. Hetrick , Doug Toussaint

As a model for nonideal behavior in the equation of state of QCD at high density, we consider cold quark matter in perturbation theory. To second order in the strong coupling constant, $\alpha_s$, the results depend sensitively on the…

High Energy Physics - Phenomenology · Physics 2009-12-31 Eduardo S. Fraga , Robert D. Pisarski , Jurgen Schaffner-Bielich

We show that there are many candidates for the quintessence and/or the QCD axions in a class of chiral $U(1)$ gauge theories. Their qualities are high enough to serve as the dark energy and/or to solve the strong CP problem. Interestingly,…

High Energy Physics - Phenomenology · Physics 2023-08-17 Yu-Cheng Qiu , Jin-Wei Wang , Tsutomu T. Yanagida

A viable formulation of gauge theory with extra generations in terms of quaternionic fields is presented. For the theory to be acceptable, the number of generations should be equal to or greater than 4. The quark-lepton mass matrices are…

High Energy Physics - Phenomenology · Physics 2009-10-30 C. S. Lim

We perform an O(alpha_s^2) perturbative calculation of the equation of state of cold but dense QCD matter with two massless and one massive quark flavor, finding that perturbation theory converges reasonably well for quark chemical…

High Energy Physics - Phenomenology · Physics 2010-06-22 Aleksi Kurkela , Paul Romatschke , Aleksi Vuorinen

The masses of quarks and leptons in units of $m_t$ are expressed in powers of $\sigma=\sqrt{m_c/m_t}$. The regularities found suggest specific mass matrices. They reproduce all masses and mixings in striking agreement with observation. A 90…

High Energy Physics - Phenomenology · Physics 2016-09-06 Berthold Stech

We investigate a composite model of spontaneous CP violation based on a new supersymmetric QCD as a solution to the strong CP problem. The scalar components of the meson chiral superfields obtain complex vacuum expectation values to break…

High Energy Physics - Phenomenology · Physics 2024-06-04 Shota Nakagawa , Yuichiro Nakai , Yaoduo Wang

A new possibility for solving the strong CP-problem is suggested,which assumes that apart of the ordinary world of observable particles described by standard model, there exits a mirror sector of particles and two sectors share the same…

High Energy Physics - Phenomenology · Physics 2009-10-31 Zurab Berezhiani , Leonida Gianfagna , Maurizio Giannotti

We show that the de Sitter quantum breaking bound when applied to QCD exposes the necessity of the axion solution to the strong CP problem. The Peccei-Quinn mechanism emerges as a consistency requirement independent of the naturalness…

High Energy Physics - Theory · Physics 2018-11-08 Gia Dvali , Cesar Gomez , Sebastian Zell

For almost twenty years the effects of a nonzero strange quark mass on the equation of state of cold and dense QCD were considered to be negligible, thereby yielding only minor corrections to the mass-radius diagram of compact stars. By…

High Energy Physics - Phenomenology · Physics 2009-11-11 Eduardo S. Fraga

We investigate chiral symmetry breaking and strong CP violation effects in the phase diagram of strongly interacting matter. We demonstrate the effect of strong CP violating terms on the phase structure at finite temperature and densities…

High Energy Physics - Phenomenology · Physics 2015-06-03 Bhaswar Chatterjee , Hiranmaya Mishra , Amruta Mishra

Recent studies have claimed that the strong $CP$ problem does not occur in QCD, proposing a new order of limits in volume and topological sectors when studying observables on the lattice. We study the effect of the topological term on a…

High Energy Physics - Lattice · Physics 2025-02-17 David Albandea , Guilherme Catumba , Alberto Ramos

Following a suggestion by Smit, the CP odd terms of the effective action of the Standard Model, obtained by integration of quarks and leptons, are computed to sixth order within a strict covariant derivative expansion approach. No other…

High Energy Physics - Phenomenology · Physics 2009-07-22 C. Garcia-Recio , L. L. Salcedo

It is argued that QCD might solve the strong CP problem on its own. To test this idea, a lattice simulation suggests itself. In view of the difficulty of such a calculation we have, as a first step, investigated the problem in the $CP^3$…

High Energy Physics - Lattice · Physics 2015-06-25 G. Schierholz