SearcharxivSearch

arXiv · 0907.5386

Flavor Physics in the Quark Sector

Abstract

One of the major challenges of particle physics has been to gain an in-depth understanding of the role of quark flavor and measurements and theoretical interpretations of their results have advanced tremendously: apart from masses and quantum numbers of flavor particles, there now exist detailed measurements of the characteristics of their interactions allowing stringent tests of Standard Model predictions. Among the most interesting phenomena of flavor physics is the violation of the CP symmetry that has been subtle and difficult to explore. Till early 1990s observations of CP violation were confined to neutral $K$ mesons, but since then a large number of CP-violating processes have been studied in detail in neutral $B$ mesons. In parallel, measurements of the couplings of the heavy quarks and the dynamics for their decays in large samples of $K, D$, and $B$ mesons have been greatly improved in accuracy and the results are being used as probes in the search for deviations from the Standard Model. In the near future, there will be a transition from the current to a new generation of experiments, thus a review of the status of quark flavor physics is timely. This report summarizes the results of the current generation of experiments that is about to be completed and it confronts these results with the theoretical understanding of the field.

Explore related subjects

Keep this discovery

BibTeXRIS

M. Antonelli, D. M. Asner, D. Bauer, T. Becher, M. Beneke, A. J. Bevan, M. Blanke, C. Bloise, M. Bona, A. Bondar, C. Bozzi, J. Brod, A. J. Buras, N. Cabibbo, A. Carbone, G. Cavoto, V. Cirigliano, M. Ciuchini, J. P. Coleman, D. P. Cronin-Hennessy, J. P. Dalseno, C. H. Davies, F. DiLodovico, J. Dingfelder, Z. Dolezal, S. Donati, W. Dungel, U. Egede, G. Eigen, R. Faccini, T. Feldmann, F. Ferroni, J. M. Flynn, E. Franco, M. Fujikawa, I. K. Furic, P. Gambino, E. Gardi, T. J. Gershon, S. Giagu, E. Golowich, T. Goto, C. Greub, C. Grojean, D. Guadagnoli, U. A. Haisch, R. F. Harr, A. H. Hoang, T. Hurth, G. Isidori, D. E. Jaffe, A. Jüttner, S. Jäger, A. Khodjamirian, P. Koppenburg, R. V. Kowalewski, P. Krokovny, A. S. Kronfeld, J. Laiho, G. Lanfranchi, T. E. Latham, J. Libby, A. Limosani, D. Lopes Pegna, C. D. Lu, V. Lubicz, E. Lunghi, V. G. Lüth, K. Maltman, W. J. Marciano, E. C. Martin, G. Martinelli, F. Martinez-Vidal, A. Masiero, V. Mateu, F. Mescia, G. Mohanty, M. Moulson, M. Neubert, H. Neufeld, S. Nishida, N. Offen, M. Palutan, P. Paradisi, Z. Parsa, E. Passemar, M. Patel, B. D. Pecjak, A. A. Petrov, A. Pich, M. Pierini, B. Plaster, A. Powell, S. Prell, J. Rademaker, M. Rescigno, S. Ricciardi, P. Robbe, E. Rodrigues, M. Rotondo. 2009-07-29. Flavor Physics in the Quark Sector. https://doi.org/10.1016/j.physrep.2010.05.003

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