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Related papers: The discrete charm of flavour and CP violation

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We emphasise that even in the extreme chiral limit where only the top and bottom quarks acquire mass, quark mixing is physically meaningful. This implies that the natural value of $|V_{13}|^2 + |V_{23}|^2$ is of order one, which is to be…

High Energy Physics - Phenomenology · Physics 2018-06-08 F. J. Botella , G. C. Branco , M. Nebot , M. N. Rebelo , J. I. Silva-Marcos

We show how a novel fine-tuning problem present in the Standard Model can be solved through the introduction of a single flavour symmetry G, together with three $Q = - 1/3$ quarks, three $Q = 2/3$ quarks, as well as a complex singlet…

High Energy Physics - Phenomenology · Physics 2017-08-02 Francisco J. Botella , G. C. Branco , Miguel Nebot , M. N. Rebelo , J. I. Silva-Marcos

We point out that, in the context of the SM, $|V^2_{13}| + | V^2_{23}|$ is expected to be large, of order one. The fact that $|V^2_{13}| + |V^2_{23}| \approx 1.6 \times 10^{-3}$ motivates the introduction of a symmetry S which leads to…

High Energy Physics - Phenomenology · Physics 2017-01-04 F. J. Botella , G. C. Branco , M. N. Rebelo , J. I. Silva-Marcos

The Standard Model (SM) of particle physics fails to explain the observed hierarchy in fermion masses or the origin of fermion-flavor structure. We construct a model to explain these observations in the quark sector. We introduce a spectrum…

High Energy Physics - Phenomenology · Physics 2026-03-16 Bhubanjyoti Bhattacharya , Suneth Jayawardana , Nausheen R. Shah

In the context of the Calabi-Yau string model we discuss the origin of characteristic pattern of quark-lepton masses and the CKM matrix. The discrete $R$-symmetry $Z_{2k+1} \times Z_2$ is introduced and the $Z_2$ is assigned to the…

High Energy Physics - Phenomenology · Physics 2007-05-23 Naoyuki Haba , Chuichiro Hattori , Masahisa Matsuda , Takeo Matsuoka , 26pages

In this talk we report on a study on the mixing of neutral charmed mesons and argue that, at the present stage, a CP violating weak phase of the order of some per mille can not be excluded in the Standard Model. It is shown how some,…

High Energy Physics - Phenomenology · Physics 2011-04-22 Markus Bobrowski , Alexander Lenz

We construct a model for the quark mass and flavor mixing matrices, based on the hypothesis that the flavor weak eigenstates in the three families are distinguished by a spontaneously broken discrete $Z_6$ chiral symmetry. In a leading…

High Energy Physics - Phenomenology · Physics 2007-05-23 S. L. Adler

We put forward the conjecture that the small numbers in the $V_\text{CKM}$ matrix, are generated by physics beyond the Standard Model. We identify as small numbers $V_{ub}$ and the strength of CP violation, measured by $|\text{Im}Q|$, where…

High Energy Physics - Phenomenology · Physics 2023-02-15 G. C. Branco , José Filipe Bastos , J. I. Silva-Marcos

We extend the standard model with two extra Higgs doublets. Making use of a symmetry principle, we present flavour symmetries based on cycle groups $Z_N$ that oblige each Higgs doublet to contribute to the mass of only one generation, thus…

High Energy Physics - Phenomenology · Physics 2017-10-30 Nuno Rosa Agostinho , David Emmanuel-Costa , J. I. Silva-Marcos

We briefly review some recent developments in theoretical models of fermion masses, mixings and CP violation with discrete non-Abelian symmetries. Then, we explain the main ideas of a recently proposed Minimal S_3 Invariant Extension of the…

High Energy Physics - Phenomenology · Physics 2010-12-13 A. Mondragon

We argue that flavour mixing, both in the quark and lepton sector, follows the minimal mixing pattern, according to which the whole of this mixing is basically determined by the physical mass generation for the first family of fermions. So,…

High Energy Physics - Phenomenology · Physics 2008-11-26 J. L. Chkareuli , C. D. Froggatt , H. B. Nielsen

The multi-Higgs models having spontaneous CP violation (SPCV) and natural flavor conservation (NFC) lead to a real CKM matrix $V$ contradicting current evidence in favour of a complex $V$. This contradiction can be removed by using a…

High Energy Physics - Phenomenology · Physics 2009-01-16 Anjan S. Joshipura , Bhavik P. Kodrani

We review and update the constraints on the parameters of the quark flavour mixing matrix $V_{CKM}$ in the standard model and estimate the resulting CP asymmetries in $B$ decays, taking into account recent experimental and theoretical…

High Energy Physics - Phenomenology · Physics 2010-11-23 A. Ali , D. London

We consider a model in which dark matter is stable as it is charged under a Z2 symmetry that is residual after an A4 flavour symmetry is broken. We consider the possibility to generate the quark masses by charging the quarks appropriately…

High Energy Physics - Phenomenology · Physics 2015-03-19 Reinier de Adelhart Toorop , Federica Bazzocchi , Stefano Morisi

We explore calculable models with low-energy supersymmetry where the flavor hierarchy is generated by quark and lepton compositeness, and where the composites emerge from the same sector that dynamically breaks supersymmetry. The observed…

High Energy Physics - Phenomenology · Physics 2014-11-20 Nathaniel Craig , Rouven Essig , Sebastian Franco , Shamit Kachru , Gonzalo Torroba

The standard model does not provide an explanation of the observed alignment of quark flavors i.e. why are the up and down quarks approximately aligned in their weak interactions according to their masses? We suggest a resolution of this…

High Energy Physics - Phenomenology · Physics 2018-10-17 Abhish Dev , Rabindra N. Mohapatra

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

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

The observed hierarchy of the quark masses is interpreted as a signal for an underlying ``subnuclear democracy'' as the relevant symmetry of the quark mass terms. A simple breaking of the symmetry leads to a mixing between the second and…

High Energy Physics - Phenomenology · Physics 2009-10-30 Harald Fritzsch

The $D_4$ flavor model based on $\mathrm{SU}(3)_C \otimes \mathrm{SU}(3)_L \otimes \mathrm{U}(1)_X$ gauge symmetry that aims at describing quark mass and mixing is updated. After spontaneous breaking of flavor symmetry, with the constraint…

High Energy Physics - Phenomenology · Physics 2015-07-30 V. V. Vien , H. N. Long

It is pointed out that if a flavor symmetry (a discrete symmetry, a U(1) symmetry, and so on) exists, we cannot obtain the observed CKM quark mixing matrix V_q and MNS lepton mixing matrix U_\ell, even if we can obtain reasonable mass…

High Energy Physics - Phenomenology · Physics 2007-05-23 Yoshio Koide
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