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In this talk I review some recent results from lattice QCD calculations which aim to a more accurate determination of the Standard Model parameters in the quark sector. After a review of our current knowledge of these parameters, I present…

High Energy Physics - Phenomenology · Physics 2007-05-23 V. Lubicz

We show that the observed pattern of quark flavor mixing, such as |V_{us}| \simeq |V_{cd}|, |V_{cb}| \simeq |V_{ts}|, |V_{cd}/V_{td}| \simeq |V_{cs}/V_{ts}| \simeq |V_{tb}/V_{cb}| and |V_{ub}/V_{cb}| < |V_{td}/V_{ts}|, can essentially be…

High Energy Physics - Phenomenology · Physics 2015-06-12 Zhi-zhong Xing

The problem of quark-lepton families is discussed in the "bottom-up" phenomenological approach to the extensions of the Standard model. It provides the possibility of the {\it Horizontal unification} of the three known families on the basis…

High Energy Physics - Phenomenology · Physics 2013-07-02 Maxim Yu. Khlopov

The anomalies in the $B$-meson sector, in particular $R_{K^{(*)}}$ and $R_{D^{(*)}}$, are often interpreted as hints for physics beyond the Standard Model. To this end, leptoquarks or a heavy $Z'$ represent the most popular SM extensions…

High Energy Physics - Phenomenology · Physics 2021-01-07 Thomas Faber , Matěj Hudec , Michal Malinský , Peter Meinzinger , Werner Porod , Florian Staub

We point out that in the Standard Model (SM) there is no explanation why $|V_{23}|^2 + |V_{13}|^2$ is of order $10^{-3}$. A framework is described for explaining this small mixing, involving the introduction of vector-like quarks. A…

High Energy Physics - Phenomenology · Physics 2017-09-13 G. C. Branco , M. N. Rebelo

To study a flavour model with a non-minimal Higgs sector one must first define the symmetries of the fields; then identify what types of vacua exist and how they may break the symmetries; and finally determine whether the remnant symmetries…

High Energy Physics - Phenomenology · Physics 2014-07-18 R. Gonzalez Felipe , I. P. Ivanov , C. C. Nishi , Hugo Serodio , Joao P. Silva

A simple breaking of the subnuclear democracy among the quarks leads to a mixing between the second and the third family, in agreement with observation. Introducing the mixing between the first and the second family, one finds an…

High Energy Physics - Phenomenology · Physics 2007-05-23 Harald Fritzsch

We show that a simple extension of the Standard Model involving the introduction of vector-like quarks and heavy neutrinos, provides an explanation of the so called B-anomalies in $b\to s\ell\bar\ell$ transitions. Vector-like quarks can…

High Energy Physics - Phenomenology · Physics 2017-12-14 Francisco J. Botella , Gustavo C. Branco , Miguel Nebot

I review recent results from experiments on rare decays of kaons, concentrating on searches for lepton flavor violation (LFV) and on measurements of quark mixing (CKM) matrix elements. The LFV results are the culmination of 15 years of…

High Energy Physics - Experiment · Physics 2011-04-15 W. Molzon

Flavour physics represents a unique test bench for the Standard Model (SM). New analyses performed at the LHC experiments are now providing unprecedented insights into CKM metrology and new evidences for rare decays. The CKM picture can…

We extend a previously developed description of the flavour parameters in the charged fermion sector, based on a U(2) flavour symmetry, to include two main features of the neutrino sector seemingly implied by recent data: a large mixing…

High Energy Physics - Phenomenology · Physics 2014-11-17 Riccardo Barbieri , Paolo Creminelli , Andrea Romanino

Based on the hierarchy exhibited by quarks masses at low energies, we assume that Yukawa couplings of up and down quarks are related by $Y_u\propto Y_d^2$ at grand unification scales. This ansatz gives rise to a symmetrical CKM matrix at…

High Energy Physics - Phenomenology · Physics 2008-11-26 H. González , S. R. Juárez W. , P. Kielanowski , G. López Castro

The results of a previous search by the CMS Collaboration for squarks and gluinos are reinterpreted to constrain models of leptoquark (LQ) production. The search considers jets in association with a transverse momentum imbalance, using the…

High Energy Physics - Experiment · Physics 2018-08-15 CMS Collaboration

We explore the phenomenology of charged Higgs bosons ($H^\pm$) and Vector-Like Quarks (VLQs), specifically the top-like $T$, within the Two Higgs Doublet Model Type-II (2HDM-II). We consider both a singlet VLQ $(T)$ and a doublet $(TB)$…

High Energy Physics - Phenomenology · Physics 2024-09-25 Rachid Benbrik , Mohammed Boukidi , Stefano Moretti

Vector-like quarks (VLQ) that couple preferentially to third-generation Standard Model (SM) quarks are a well-motivated extension of the SM, which could solve in particular the hierarchy problem. While VLQs can be produced in pairs via the…

High Energy Physics - Experiment · Physics 2018-11-29 Johannes Erdmann

I present the status of the elements and parameters of the Cabibbo-Kobayashi-Maskawa (CKM) matrix and summarise the related theoretical progress since "Lepton-Photon 2003". One finds |V_{us}| = 0.2227 +/- 0.0017 from K and tau decays and…

High Energy Physics - Phenomenology · Physics 2009-11-11 Ulrich Nierste

A preliminary determination of the Dirac phase in the PMNS matrix is $\dell\approx -\frac{\pi}{2}$. A rather accurately determined Jarlskog invariant $J$ in the CKM matrix is close to the maximum. Since the phases in the CKM and PMNS…

High Energy Physics - Phenomenology · Physics 2016-02-17 Jihn E. Kim , Soonkeon Nam

We show that it is possible to accommodate the observed size of the phase in $B^0_s$--$\bar B^0_s$, mixing in the framework of a model with violation of $3\times 3$ unitarity. This violation is associated to the presence of a new $Q=2/3$…

High Energy Physics - Phenomenology · Physics 2009-07-30 Francisco J. Botella , Gustavo C. Branco , Miguel Nebot

Di-Higgs couplings to fermions of the form $h^{2}\overline{f}f$ are absent in the Standard Model, however, they are present in several physics Beyond Standard Model (BSM) extensions, including those with vector-like fermions. In Effective…

High Energy Physics - Phenomenology · Physics 2024-09-25 Fayez Abu-Ajamieh , Marco Frasca , Sudhir K. Vempati

Motivated by the $R_K$ and $R_{K^*}$ anomalies from B decays, we extend the minimal supersymmetric model with a non-universal anomaly-free $U(1)^\prime$ gauge symmetry, coupling non-universally to the lepton sector as well as the quark…

High Energy Physics - Phenomenology · Physics 2018-12-12 Guang Hua Duan , Xiang Fan , Mariana Frank , Chengcheng Han , Jin Min Yang