Search

We use the numerical S-matrix bootstrap method to obtain bounds on the two leading Wilson coefficients of the chiral lagrangian controlling the low-energy dynamics of massless pions thus providing a proof of concept that the numerical S-matrix bootstrap can be used to derive non-perturbative bounds on EFTs in more than two spacetime dimensions., Comment: 12 pages + appendices

Measuring the spin structure of protons and neutrons tests our understanding of how they arise from quarks and gluons, the fundamental building blocks of nuclear matter. At long distances the coupling constant of the strong interaction becomes large, requiring non-perturbative methods to calculate quantum chromodynamics processes, such as lattice gauge theory or effective field theories. Here we report proton spin structure measurements from scattering a polarized electron beam off polarized protons. The spin-dependent cross-sections were measured at large distances, corresponding to the region of low momentum transfer squared between 0.012 and 1.0 GeV$^2$. This kinematic range provides unique tests of chiral effective field theory predictions. Our results show that a complete description of the nucleon spin remains elusive, and call for further theoretical works, e.g. in lattice quantum chromodynamics. Finally, our data extrapolated to the photon point agree with the Gerasimov-Drell-Hearn sum rule, a fundamental prediction of quantum field theory that relates the anomalous magnetic moment of the proton to its integrated spin-dependent cross-sections., Published version. 10 pages, 5 figures. 20 pages of supplementary material (data tables and a figure)

We calculate the gravitational form factors of the excited $N(1535)$ state with the quantum numbers $I(J^P)=\frac{1}{2}(\frac{1}{2}^-)$ via light cone QCD sum rules (LCSR). To this end, we consider the quark part of the energy-momentum tensor (EMT) current and use the general form of the nucleon's interpolating field as well as the distribution amplitudes (DAs) of $N(1535)$. As both the nucleon and $N(1535)$ couple to the same current, the $N(1535) \rightarrow N$ gravitational transition form factors are entered to the calculations as the main input parameters. First we revisit the transitional gravitational form factors of $N(1535) \rightarrow N$, then extract the values of the form factors of the $N(1535)$ excited state. We observe that the gravitational form factors of $N(1535)$ in terms of $Q^2$ are well described by the multipole fit function. As a byproduct, we also calculate the pressure and energy density at the center of $N(1535)$ and estimate its mechanical radius., 12 Pages, 2 Figures and 3 Tables

We explore the breaking of Lorentz and CPT invariance in strong interactions at low energy in the framework of chiral perturbation theory. Starting from the set of Lorentz-violating operators of mass-dimension five with quark and gluon fields, we construct the effective chiral Lagrangian with hadronic and electromagnetic interactions induced by these operators. We develop the power-counting scheme and discuss loop diagrams and the one-pion-exchange nucleon-nucleon potential. The effective chiral Lagrangian is the basis for calculations of low-energy observables with hadronic degrees of freedom. As examples, we consider clock-comparison experiments with nuclei and spin-precession experiments with nucleons in storage rings. We derive strict limits on the dimension-five tensors that quantify Lorentz and CPT violation., Comment: 38 pages, 1 figure, updated to match published version

We review the status of the proton charge radius puzzle. Emphasis is given to the various experiments initiated to resolve the conflict between the muonic hydrogen results and the results from scattering and regular hydrogen spectroscopy., EPJ Web of Conferences, 113, ISSN:2100-014X, ISSN:2101-6275

The low-energy and low-momentum dynamics of systems with a spontaneously broken continuous symmetry is dominated by the ensuing Nambu-Goldstone bosons. It can be conveniently encoded in a model-independent effective field theory whose structure is fixed by symmetry up to a set of effective coupling constants. We construct the most general effective Lagrangian for the Nambu-Goldstone bosons of spontaneously broken global internal symmetry up to the fourth order in derivatives. Rotational invariance and spatial dimensionality of one, two or three are assumed in order to obtain compact explicit expressions, but our method is completely general and can be applied without modifications to condensed matter systems with a discrete space group as well as to higher-dimensional theories. The general low-energy effective Lagrangian for relativistic systems follows as a special case. We also discuss the effects of explicit symmetry breaking and classify the corresponding terms in the Lagrangian. Diverse examples are worked out in order to make the results accessible to a wide theoretical physics community., Comment: 45 pages

We perform a systematic study of flavor-diagonal parity- and time-reversal-violating operators of dimension six which could arise from physics beyond the SM. We begin at the unknown high-energy scale where these operators originate. At this scale the operators are constrained by gauge invariance which has important consequences for the form of effective operators at lower energies. In particular for the four-quark operators. We calculate one-loop QCD and, when necessary, electroweak corrections to the operators and evolve them down to the electroweak scale and subsequently to hadronic scales. We find that for most operators QCD corrections are not particularly significant. We derive a set of operators at low energy which is expected to dominate hadronic and nuclear EDMs due to physics beyond the SM and obtain quantitative relations between these operators and the original dimension-six operators at the high-energy scale. We use the limit on the neutron EDM to set bounds on the dimension-six operators., Matches published version, 35 pages, 6 figures, minor corrections

We calculate the toroidal quadrupole moment and form factor of the deuteron, which violate time-reversal symmetry but conserve parity, at leading order in two-flavor chiral effective field theory with perturbative pion exchange. We take into account time-reversal and parity violation owing to the QCD vacuum angle combined with parity violation resulting from the weak interaction in the Standard Model. We also consider time-reversal and parity violation that at the quark-gluon level results from effective dimension-six operators originating from physics beyond the Standard Model.

Recent experimental results in three-body systems have unambiguously shown that calculations based only on nucleon-nucleon forces fail to accurately describe many experimental observables and one needs to include effects which are beyond the realm of the two-body potentials. This conclusion owes its significance to the fact that experiments and calculations can both be performed with a high accuracy. In this review, both theoretical and experimental achievements of the past decade will be underlined. Selected results will be presented. The discussion on the effects of the three-nucleon forces is, however, limited to the hadronic sector. It will be shown that despite the major successes in describing these seemingly simple systems, there are still clear discrepancies between data and the state-of-the-art calculations., accepted for publication in Rep. Prog. Phys

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 satisfy partial-wave dispersion relations and therefore provide a suitable basis for data analysis and the construction of effective field theories. Our derivation relies on a decomposition of the various scattering amplitudes into suitable sets of invariant functions., 12 pages, 3 tables

We calculate the electric dipole form factor of the nucleon that arises as a low-energy manifestation of time-reversal violation in quark-gluon interactions of effective dimension 6: the quark electric and chromoelectric dipole moments, and the gluon chromoelectric dipole moment. We use the framework of two-flavor chiral perturbation theory to one loop. (C) 2010 Elsevier B.V. All rights reserved.

The optimized perturbation theory (OPT) method is applied to the $SU(2)$ version of the Nambu--Jona-Lasinio (NJL) model both at zero and at finite temperature and/or density. At the first nontrivial order the OPT exhibits a class of 1/N_c corrections which produce nonperturbative results that go beyond the standard large-N_c, or mean-field approximation. The consistency of the OPT method with the Goldstone theorem at this order is established, and appropriate OPT values of the basic NJL (vacuum) parameters are obtained by matching the pion mass and decay constant consistently. Deviations from standard large-N_c relations induced by OPT at this order are derived, for example, for the Gell--Mann-Oakes-Renner relation. Next, the results for the critical quantities and the phase diagram of the model, as well as a number of other thermodynamical quantities of interest, are obtained with OPT and then contrasted with the corresponding results at large N_c., 29 pages, 20 figures, revtex. Minor corrections. In press Phys. Rev. C

We investigate the relevance of the metric and of the geometry in five-dimensional models of hadrons. Generically, the metric does not affect strongly the results and even flat space agrees reasonably well with the data. Nevertheless, we observe a preference for a decreasing warp factor, for example AdS space. The Sakai-Sugimoto model reduces to one of these models and the level of agreement is similar to the one of flat space. We also consider the discrete version of the five-dimensional models, obtained by dimensional deconstruction. We find that essentially all the relevant features of "holographic" models of QCD can be reproduced with a simple 3-site model describing only the states below the cut-off of the theory., Comment: 25 pages + appendix. v2 minor changes and Refs. added

We study charmed baryon resonances which are generated dynamically within a unitary meson-baryon coupled channel model that treats the heavy pseudoscalar and vector mesons on equal footing as required by heavy-quark symmetry. It is an extension of recent SU(4) models with t-channel vector meson exchanges to a SU(8) spin-flavor scheme, but differs considerably from the SU(4) approach in how the strong breaking of the flavor symmetry is implemented. Some of our dynamically generated states can be readily assigned to recently observed baryon resonances, while others do not have a straightforward identification and require the compilation of more data as well as an extension of the model to d-wave meson-baryon interactions and p-wave coupling in the neglected s- and u-channel diagrams. Of several novelties, we find that the Lambda_c(2595), which emerged as a ND quasi-bound state within the SU(4) approaches, becomes predominantly a ND* quasi-bound state in the present SU(8) scheme., Comment: 37 pages, 7 figures. Some parameters of the model have been changed, more channels are considered. To appear in PRD

We present results of dynamical simulations with 2 flavours of degenerate Wilson twisted mass quarks at maximal twist in the range of pseudo scalar masses from 300 to 550 MeV. The simulations are performed at one value of the lattice spacing a \lesssim 0.1 fm. In order to have O(a) improvement and aiming at small residual cutoff effects, the theory is tuned to maximal twist by requiring the vanishing of the untwisted quark mass. Precise results for the pseudo scalar decay constant and the pseudo scalar mass are confronted with chiral perturbation theory predictions and the low energy constants F, \bar{l}_3 and \bar{l}_4 are evaluated with small statistical errors., 17 pages, 5 figures, references added, typos corrected

We calculate the pi+ K+ scattering length in fully-dynamical lattice QCD with domain-wall valence quarks on MILC lattices with rooted staggered sea-quarks at a lattice spacing of b=0.125 fm, lattice spatial size of L =2.5 fm and at pion masses of m_pi=290, 350, 490 and 600 MeV. The lattice data, analyzed at next-to-leading order in chiral perturbation theory, allows an extraction of the full pi K scattering amplitude at threshold. Extrapolating to the physical point gives m_pi a_3/2 = -0.0574 (+- 0.0016)(+0.0024 -0.0058) and m_pi a_1/2 = 0.1725 (+- 0.0017)(+0.0023 -0.0156) for the I=3/2 and I=1/2 scattering lengths, respectively, where the first error is statistical and the second error is an estimate of the systematic due to truncation of the chiral expansion., 14 pages, 9 figures

Two-photon production in pp scattering is proposed as a means of studying virtual-pion emission. Such a process is complementary to real-pion emission in pp scattering. The virtual-pion signal is embedded in a background of double-photon bremsstrahlung. We have developed a model to describe this background process and show that in certain parts of phase space the virtual-pion signal gives significant contributions. In addition, through interference with the two-photon bremsstrahlung background, one can determine the relative phase of the virtual-pion process.

We present results of a numerical calculation of lattice QCD with two degenerate flavors of dynamical quarks, identified with up and down quarks, and with a strange quark treated in the quenched approximation. The lattice action and simulation parameters are chosen with a view to carrying out an extrapolation to the continuum limit as well as chiral extrapolations. Gauge configurations are generated with a renormalization-group improved gauge action and a mean field improved clover quark action at three values of $\beta$ and four sea quark masses. The sizes of lattice are chosen so that the physical spatial size is kept constant. Hadron masses, light quark masses and meson decay constants are measured at five valence quark masses. We also carry out complementary quenched simulations with the same improved actions. The quenched spectrum from this analysis agrees well in the continuum limit with the one of our earlier work using the standard action. We find the two-flavor full QCD meson masses in the continuum limit to be much closer to experimental meson masses than those from quenched QCD. We take these results as manifestations of sea quark effects in two-flavor full QCD. For baryon masses full QCD values for strange baryons are in agreement with experiment, while they differ increasingly with decreasing strange quark content, resulting in a nucleon mass higher than experiment. The pattern suggests finite size effects as a possible origin for this deviation. For light quark masses in the continuum limit we obtain values which are reduced by about 25% compared to the values in quenched QCD. We also present results for decay constants where large scaling violations obstruct a continuum extrapolation. Need for a non-perturbative estimate of renormalization factors is discussed., Comment: RevTeX, 65 pages, 42 figures

We calculate (g-2)/2 of the muon, by improving the determination of the hadronic vacuum polarisation contribution, a_mu^{had,LO}, and its uncertainties. The different e+e- data sets for each exclusive (and the inclusive) channel are combined in order to obtain the optimum estimate of the cross sections and their uncertainties. QCD sum rules are evaluated in order to resolve an apparent discrepancy between the inclusive data and the sum of the exclusive channels. We conclude a_mu^{had,LO}=(683.1 +- 5.9_{exp} +- 2.0_{rad}) 10^{-10} which, when combined with the other contributions to (g-2)/2, is about 3 sigma below the present world average measurement., Comment: 8 pages, LaTeX, 3 PostScript figures included. For completeness, we have added a recent prediction of the hadronic contribution by F. Jegerlehner

PUBLISHED, We present a comprehensive study of the masses of pseudoscalar and vector mesons, as well as octet and decuplet baryons computed in O(a)-improved quenched lattice QCD. Results have been obtained using the nonperturbative definition of the improvement coefficient csw , and also its estimate in tadpole improved perturbation theory. We investigate effects of improvement on the incidence of exceptional configurations, mass splittings, and the parameter J. By combining the results obtained using nonperturbative and tadpole improvement in a simultaneous continuum extrapolation, we can compare our spectral data to experiment. We confirm earlier findings by the CP-PACS Collaboration that the quenched light hadron spectrum agrees with experiment at the 10% level., This work was supported by the Particle Physics & Astronomy Research Council ~PPARC! through grants GR/L56336 and GR/L29927. We also acknowledge the support by EPSRC under grant GR/K41663. H.P.S. acknowledges the support of the Leverhulme foundation and the JSPS Research for the Future program. H.W. is grateful to Akira Ukawa for the hospitality at the Center of Computational Physics, University of Tsukuba, where part of this work was completed. D.G.R. and H.W. acknowledge the financial support of PPARC.

We present results of a large-scale simulation for the flavor non-singlet light hadron spectrum in quenched lattice QCD with the Wilson quark action. Hadron masses are calculated at four values of lattice spacing in the range $a \approx$ 0.1 - 0.05 fm on lattices with a physical extent of 3 fm at five quark masses corresponding to $m_\pi/m_\rho \approx 0.75$ - 0.4. The calculated spectrum in the continuum limit shows a systematic deviation from experiment, though the magnitude of deviation is contained within 11%. Results for decay constants and light quark masses are also reported., Comment: 9 pages, 4 figures, revtex

We study the influence of the off-shell structure of the nucleon electromagnetic vertex on proton-proton bremsstrahlung observables. Realistic choices for these off-shell effects are found to have considerable influences on observables such as cross sections and analyzing powers. The rescattering contribution diminishes the effects of off-shell modifications in negative-energy states., 7 pages, 3 figures

We dedicate this document to the memory of Mikhail Polikarpov, who passed away in July 2013. Misha worked with us for decades as a convener of the “Confinement” section of the Quark Confinement and Hadron Spectrum Series. He guided and expanded the scientific discussion of that topic, inspiring and under taking new research avenues. From its initial conception, he supported the enterprise of this document and organized Sect. 8, writing the part on confinement himself. He attracted the XIth Conference on Quark Confinement and the Hadron Spectrum to St. Petersburg (September 8-12, 2014; see http://phys.spbu.ru/confxi.html). His warm and kind personality, his high sense of humor, his ideas in physics, and his special energy in imagining and realizing new projects will be always a loss and an example for us. We also miss four other physicists who made lasting contributions to the field of strong interactions: Dmitri Diakonov, Nikolai Uraltsev, Pierre van Baal, and Kenneth Wilson. We remember Misha, Dima, Ken, Kolya, and Pierre with fondness and gratitude. In addition, S.G. would like to dedicate her work on this document to the memory of her mother and mentor, Gladys Strom Gardner. The authors thank Mikko Laine for collaboration during initial stages of the project. In addition, Véronique Bernard, Alex Bondar, Geoffrey T. Bodwin, Davide Caffarri, Gilberto Colangelo, Lance Dixon, Gernot Eichmann, Christoph Hanhart, Ulrich Heinz, Aleksi Kurkela, Vittorio Lubicz, Alexander Milov, Bachir Moussallam, Antonio Pineda, Brad Plaster, Massimiliano Procura, Joan Soto, Reinhard Stock, Ruth Van de Water, Ubirajara van Kolck, Julia Velkovska, and Richard Williams provided helpful correspondance and contributions during the preparation of this review. Finally, the Editors thank Małgorzata Janik for maintaining document and bibliography updates and for coordinating an editorial team of Jeremi Niedziela and Anna Zaborowska., We highlight the progress, current status, and open challenges of QCD-driven physics, in theory and in experiment. We discuss how the strong interaction is intimately connected to a broad sweep of physical problems, in settings ranging from astrophysics and cosmology to strongly coupled, complex systems in particle and condensed-matter physics, as well as to searches for physics beyond the Standard Model. We also discuss how success in describing the strong interaction impacts other fields, and, in turn, how such subjects can impact studies of the strong interaction. In the course of the work we offer a perspective on the many research streams which flow into and out of QCD, as well as a vision for future developments., The authors appreciate and acknowledge support for work on this document provided, in part or in whole, by • U.S. Department of Energy, Office of Science, Offices of Nuclear and High-Energy physics, under contracts #DE-FG02-05ER41375 and #DE-FG02-91ER40628 (M. Alford and K. Schwenzer) • the EU I3HP project EPOS “Exciting Physics of Strong Interactions” (WP4 of HadronPhysics3) (R. Alkofer) • U.S. Department of Energy grant no. DE-SC0007984, (P. Arnold) • Deutsche Forschungsgemeinschaft DFG EClust 153 “Origin and Structure of the Universe” (N. Brambilla, L. Fabbietti, B. Ketzer, A. Vairo) • Deutsche Forschungsgemeinschaft DFG grants BR 4058/2-1 and BR 4058/1-1; work supported in part by DFG and NSFC (CRC 110) (N. Brambilla, A. Vairo) • U.S. Department of Energy (T. Cohen) • Istituto Nazionale di Fisica Nucleare (INFN) of Italy (P. Di Nezza) • the Ministry of Education and Science of the Russian Federation; the Russian Foundation for Basic Research under grants 12-02-01032 and 12-02-01296 and the German Research Foundation (DFG) under grant HA 1457/9-1. (S. Eidelman) • Bundesministerium für Bildung und Forschung BMBF Grant No. 05P12WOGHH; Helmholtz Young Investigator University Group, VHNG-330 (L. Fabbietti) • Swiss National Science Foundation (SNF) under the Sinergia grant number CRSII2 141847 1 (X. Garcia i Tormo) • U.S. Department of Energy Office of Nuclear Physics under contract DE-FG02-96ER40989 (S. Gardner) • DOE Contract No. DE-AC05-06OR23177 under which JSA operates the Thomas Jefferson National Accelerator Facility, and by the National Science Foundation through grants PHY-0855789 and PHY-1307413 (J. Goity) • Austrian Science Foundation FWF under project No. P20016-N16 (R. Höllwieser) • Polish National Science Centre reaserch grant UMO-2012/05/N/ST2/ 02757 (M. A. Janik) • European Union in the framework of European Social Fund through the Warsaw University of Technology Development Programme (M. A. Janik) • U.S. Department of Energy, Office of Nuclear Physics, under grant DE-FG02-89ER40531 (D. Keane) • Bundesministerium für Bildung und Forschung BMBF Grant No. 05P12WOCC1 (B. Ketzer) • European Union program “Thales” ESF/NSRF 2007-2013 (E. Kiritsis) • European Union (European Social Fund, ESF) and Greek national funds through the Operational Program “Education and Lifelong Learning” of the National Strategic Reference Framework (NSRF) under “Funding of proposals that have received a positive evaluation in the 3rd and 4th Call of ERC Grant Schemes” (E. Kiritsis) • European Union’s Seventh Framework Programme under grant agreements (FP7-REGPOT-2012-2013-1) No. 316165, and PIF-GA-2011- 300984 and by the European Commission under the ERC Advanced Grant BSMOXFORD 228169 (E. Kiritsis) • Fermilab is operated by Fermi Research Alliance, LLC, under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy (A. S. Kronfeld) • U.S. Department of Energy Office of Nuclear Physics under contract DE-FG02-97ER4014 (H.-W. Lin) • Spanish grant FPA2011-27853-C02-01 (Felipe J. Llanes-Estrada) • Center for Computational Sciences as part of the Rhineland-Palatinate Research Initiative (H. B. Meyer) • the DFG grant ME 3622/2-1 (H. B. Meyer) • the European Research Council under the European Community’s Seventh Framework Programme (FP7/2007-2013) / ERC grant agreement No. 210223 (A. Mischke) • Netherlands Organisation for Scientific Research (project number 680-47-232) (A. Mischke) • Dutch Foundation for Fundamental Research (project number 10PR2884) (A. Mischke) • the Russian Foundation for Basic Research (grant 14-02-01220) (R. Mizuk) • U.S. Department of Energy by Lawrence Berkeley National Laboratory, Nuclear Science Division, under Contract No. DE-AC02- 05CH11231 (G. Odyniec) • Spanish Government and EU funds for regional development grants FPA2011-23778 and CSD2007-00042 (A. Pich) • Generalitat Valenciana grant PrometeoII/2013/007 (A. Pich) • the European Research Council under the European Community’s Seventh Framework Programme (FP7/2007-2013) / ERC grant agreement No. 291377 (R. Pittau) • Spanish grant FPA2011-22398 (R. Pittau) •U. S. Department of Energy under contract No. DE-AC02-98CH10886 and the National Science Foundation under grant Nos. PHY-0969739 and -1316617 (J.-W. Qiu) • Italian MIUR under project 2010YJ2NYW and INFN under specific initiative QNP (G. Ricciardi) • The European Research Council grant HotLHC ERC-2011-StG279579; by Ministerio de Ciencia e Innovacion of Spain (FPA2009- 11951) and by Xunta de Galicia. (C. A. Salgado) • the EU I3HP project “Study of Strongly Interacting Matter” (acronym HadronPhysics3), Grant Agreement No. 283286 (H. Sazdjian) • Austrian Science Foundation FWF under project No. P23536-N16 (A. Schmitt) •NSF PHY-0969490 and Indiana University Center for Spacetime Symmetries (W. M. Snow) • Lawrence Livermore National Laboratory is operated by Lawrence Livermore National Security, LLC, for the U.S. Department of Energy, National Nuclear Security Administration, under Contract DE-AC52- 07NA27344. The work is also supported in part by the US DOE JET topical collaboration. (R. Vogt) • Academy of Finland, grant # 266185 (A. Vuorinen)

We present details of simulations for the light hadron spectrum in quenched QCD carried out on the CP-PACS parallel computer. Simulations are made with the Wilson quark action and the plaquette gauge action on 32^3x56 - 64^3x112 lattices at four lattice spacings (a \approx 0.1-0.05 fm) and the spatial extent of 3 fm. Hadronic observables are calculated at five quark masses (m_{PS}/m_V \approx 0.75 - 0.4), assuming the u and d quarks being degenerate but treating the s quark separately. We find that the presence of quenched chiral singularities is supported from an analysis of the pseudoscalar meson data. We take m_\pi, m_\rho and m_K (or m_\phi) as input. After chiral and continuum extrapolations, the agreement of the calculated mass spectrum with experiment is at a 10% level. In comparison with the statistical accuracy of 1-3% and systematic errors of at most 1.7% we have achieved, this demonstrates a failure of the quenched approximation for the hadron spectrum: the meson hyperfine splitting is too small, and the octet masses and the decuplet mass splittings are both smaller than experiment. Light quark masses are calculated using two definitions: the conventional one and the one based on the axial-vector Ward identity. The two results converge toward the continuum limit, yielding m_{ud}=4.29(14)^{+0.51}_{-0.79} MeV. The s quark mass depends on the strange hadron mass chosen for input: m_s = 113.8(2.3)^{+5.8}_{-2.9} MeV from m_K and m_s = 142.3(5.8)^{+22.0}_{-0} MeV from m_\phi, indicating again a failure of the quenched approximation. We obtain \Lambda_{\bar{MS}}^{(0)}= 219.5(5.4) MeV. An O(10%) deviation from experiment is observed in the pseudoscalar meson decay constants., Comment: 60 pages, 49 figures

218 páginas, 106 figuras, 89 tablas.-- arXiv:0907.5386v2.-- Report of the CKM workshop, Rome 9-13th Sep. 2008.-- et al., 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., We would like to thank the Universit´a ”Sapienza” of Rome and in particular its Department of Physics for the hospitality during the days of the workshop (9-13 September 2008). For the finantial and organizational support to the workshop itself we would like to thank INFN and in particular its Roma1 Section and the Local Organizing Committee (D. Anzellotti, C. Bulfon, G. Bucci, E. Di Silvestro, R. Faccini, M. Mancini, G. Piredda, and R. Soldatelli) respectively. The program of the workshop was elaborated by the Programm Committee (P. Ball, G. Cavoto, M. Ciuchini, R. Faccini – chair, R. Forty, S. Giagu, P. Gambino, B. Grinstein, S. Hashimoto, T. Iijima, G. Isidori, V. Luth, G. Piredda, M. Rescigno, and A. Stocchi) under consultation of the International Advisory Committee (I. I. Bigi, C. Bloise, A. Buras, N. Cabibbo, A. Ceccucci, P. Chang, F. Ferroni, A. Golutvin, A. Jawahery, A. S. Kronfeld, Y. Kwon, M. Mangano, W. J. Marciano, G. Martinelli, A. Masiero, T. Nakada, M. Neubert, P. Roudeau, A. I. Sanda, M. D. Shapiro, I. P.J. Shipsey, A. Soni, W. J. Taylor, N. G. Uraltsev, and M. Yamauchi). This work is supported by Australian Research Council and the Australian Department of Industry Innovation, Science and Research, the Natural Sciences and Engineering Research Council (Canada), the National Science Fundation of China, the Commissariat `a l’Energie Atomique and Institut National de Physique Nucl´eaire et de Physique des Particules (France), the Bundesministerium f¨ur Bildung und Forschung and Deutsche Forschungsgemeinschaft (Germany), the Department of Science and Technology of India the Istituto Nazionale di Fisica Nucleare (Italy), the Ministry of Education Culture, Sports, Science, and Technology (Japan), the Japan Society of Promotion of Science, the BK21 program of the Ministry of Education of Korea, the Research Council of Norway, the Ministry of Education and Science of the Russian Federation, the Slovenian Research Agency, Ministerio de Educaci´on y Ciencia (Spain), the Science and Technology Facilities Council (United Kingdom), and the US Department of Energy and National Science Foundation . Individuals have received support from European Community’s Marie-Curie Research Training Networks under contracts MRTN-CT-2006-035505 (‘Tools and Precision Calculations for Physics Discoveries at Colliders’) and MRTN-CT-2006-035482 (’FLAVIAnet’), from the National Science Fundation of China (grants 10735080 and 10625525), the DFG Cluster of Excellence ’Origin and Structure of the Universe’ (grant BU 706/2-1), the Jpan Society for the Promotion of Science (grant 20244037), and the A. von Humboldt Stiftung, from MICINN, Spain (grant FPA2007-60323), from the ITP at University of Zurich, from the US National Science Fundation (grant PHY-0555304) and Department of Energy (grants DE-FG02-96ER41005 and DE-AC02-07CH11359 – Fermi Research Alliance, LLC), and from Generalitat Valenciana (grant PROMETEO/2008/069).