SearcharxivSearch

arXiv · hep-ph/9706483

Dynamically generated masses in supersymmetric QCD and quark mass problems

Abstract

We consider possible mechanical masses that could appear in supersymmetry, other than by direct Higgs coupling to fermions and we speculate that the existence of such a type of mass would allow one to have the Higgs mass of the $u$ quark zero, and the Higgs mass of the $d$ quark (at 1 \gev) of $\approx 1 \to 2 MeV$, thus solving at the same time the strong CP problem and arranging the grand unification prediction $m_μ/m_{e} = m_{s, Higgs}/m_{d, Higgs}.$ One possible mechanism for this is related to, but not identical with the quark condensate. Here a mass is generated which is the same for all quarks, and which adds to the Higgs type mass. Unfortunately, the numerical value of the generated mass falls short of the desired value (some 5 MeV) by orders of magnitude. An alternate mechanism, through Higgs-induced left-right couplings in the squark sector may produce masses of the correct order of magnitude if the mixing angles are diferent in the squark and quark sectors. To get the desired result for the $u$ quark mass, we need a stop component mixing of 1/20 for the $LR$ $\tilde{u}$ squark coupling, so the strong CP problem may still be solved. For the $d$ mass, this mechanism is not really sufficient to solve the grand unification mass ratio problem.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

F. J. Yndurain. 1997-06-24. Dynamically generated masses in supersymmetric QCD and quark mass problems. https://doi.org/10.1016/s0370-2693(97)01334-8

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Axionic Wormholes in Metric-Affine Gravity

The axion is a promising candidate for solving the strong CP problem. To solve this problem, the global U(1) symmetry must be preserved to a high degree of accuracy. However, it is well known that global symmetries are explicitly violated by quantum gravity effects, giving rise to what is referred to as the axion quality problem. In this paper, we investigate axionic wormholes as a source of explicit U(1) violation in Metric-Affine Gravity. This framework allows for spacetime torsion and non-metricity, which accommodate additional curvature-like and topological terms, such as the Holst and Nieh--Yan terms, that are absent from the metric and Palatini formalisms. We show that non-minimal couplings to these terms modify the wormhole dynamics and enhance the Euclidean wormhole action, thereby alleviating the axion quality problem. We also find that the viable parameter space is enlarged when two of these couplings are simultaneously present. We further identify representative parameter regions where the alleviation of the axion quality problem is compatible with inflationary constraints.

hep-ph

Qubit-Qutrit Quantum Tomography of hadronic $\Lambda\phi$ and $\Lambda K^{\ast 0}$ systems

Quantum-information observables have emerged in recent years as new tools in nuclear and particle physics, from entanglement in top-quark pairs to spin correlations in $\Lambda\bar{\Lambda}$ production. Extending these studies to unequal-spin hadronic final states poses a fundamental challenge: the $6\times6$ density matrix of a qubit-qutrit system contains 35 independent spin parameters, but the decays of $\Lambda V$ pairs, with $V=\phi$ or $K^{*0}$, provide access to only 23 due to the hidden vector polarization from the strong decay. In this Letter, we formulate a qubit-qutrit quantum tomography (QQQT) technique for these spin-$\tfrac{1}{2}\otimes1$ systems and establish exact criteria for entanglement certification from the \textit{incomplete} density matrix. Compared with the $\Lambda\bar{\Lambda}$ system, QQQT of $\Lambda\phi$ and $\Lambda K^{*0}$ provides a new probe of nonperturbative QCD hadronization, enabling a direct comparison of the spin evolution of entangled quark pairs produced from the vacuum as they hadronize into a baryon or a vector meson.

hep-ph

Twist decomposition of exclusive heavy meson production cross sections

We study the twist decomposition of the total cross sections for exclusive heavy vector meson electroproduction and photoproduction in the $\gamma^\ast p$ processes, within the leading logarithmic $1/x$ BFKL formalism. The Mellin transforms of the impact factors of the vector meson are calculated. We show that the higher twist contributions are strongly suppressed in the low-$x$ kinematical regime. Possible enhancement of the higher twists effects for nuclei targets is discussed.

hep-ph