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Related papers: Feasible Deviations from Unitarity with Vector-Lik…

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Current experimental data indicate that two unitarity triangles of the CKM quark flavor mixing matrix V are almost the right triangles with \alpha \approx 90^\circ. We find that \alpha = 90^\circ actually points to {\rm…

High Energy Physics - Phenomenology · Physics 2009-08-17 Zhi-zhong Xing

In this letter, using a rephasing invariant formula $\delta = \arg [ { V_{ud} V_{us} V_{c b} V_{tb} / V_{ub} \det V_{\rm CKM} }]$, we evaluate the CP phase $\delta$ of the CKM matrix $V_{\rm CKM}$ perturbatively for small quark mixing…

High Energy Physics - Phenomenology · Physics 2026-02-03 Masaki J. S. Yang

The first row of the Cabibbo-Cobayashi-Maskawa (CKM) matrix shows a discrepancy of $\sim $$3\,\sigma$ with unitarity, known as the "Cabibbo Angle Anomaly" (CAA). This tension can be explained via modified $W$ couplings to leptons, but in…

High Energy Physics - Phenomenology · Physics 2021-05-10 Claudio Andrea Manzari

Motivated by the recent determination of the top quark mass by the CDF collaboration, $\mt =174 \pm 10 ^{+13}_{-12}$ GeV, we review and update the constraints on the parameters of the quark flavour mixing matrix $V_{CKM}$ in the standard…

High Energy Physics - Phenomenology · Physics 2010-11-01 A. Ali , D. London

We consider the phenomenology at the Large Hadron Collider of new heavy vector-like quarks which couple mainly to the third generation quarks via Yukawa interactions, with special emphasis on non-standard doublet representations which are…

High Energy Physics - Phenomenology · Physics 2015-05-30 Giacomo Cacciapaglia , Aldo Deandrea , Naveen Gaur , Daisuke Harada , Yasuhiro Okada , Luca Panizzi

Deviations from unitarity of the CKM matrix in the quark sector are considered excellent windows to probe physics beyond the Standard Model. In its leptonic counterpart, the PMNS matrix, these searches are particularly motivated, as the new…

The ATLAS and CMS collaborations at the LHC have performed analyses on the existing data sets, studying the case of one vector-like fermion or multiplet coupling to the standard model Yukawa sector. In the near future, with more data…

High Energy Physics - Phenomenology · Physics 2015-02-03 Giacomo Cacciapaglia , Aldo Deandrea , Naveen Gaur , Daisuke Harada , Yasuhiro Okada , Luca Panizzi

In this letter, we perform an almost general analysis of flavor-mixing matrices $V_{\rm CKM}$ and $U_{\rm MNS}$ to investigate the discriminative power of CP phases by next-generation neutrino oscillation experiments. As an approximation,…

High Energy Physics - Phenomenology · Physics 2024-12-06 Masaki J. S. Yang

The complementarity between the quark and lepton mixing matrices is shown to provide robust predictions. We obtain these predictions by first showing that the matrix V_M, product of the quark (CKM) and lepton (PMNS) mixing matrices, may…

High Energy Physics - Phenomenology · Physics 2009-06-11 Marco Picariello , Bhag C. Chauhan , Joao Pulido , Emilio Torrente-Lujan

Using unitarity, unlike the approaches available in the literature, we have constructed 9 independent representations of CKM matrix starting with each of the 9 elements of the matrix. The relationship of these independently constructed…

High Energy Physics - Phenomenology · Physics 2024-06-25 Gurjit Kaur , Aakriti Bagai , Gulsheen Ahuja , Manmohan Gupta

We study the flavor physics in two extensions of the quark sector of the Standard Model (SM): a four generation model and a model with a single vector--like down--type quark (VDQ). In our analysis we take into account the experimental…

High Energy Physics - Phenomenology · Physics 2009-11-07 Tomer Yanir

Unitarity is a fundamental property of any theory required to ensure we work in a theoretically consistent framework. In comparison with the quark sector, experimental tests of unitarity for the 3x3 neutrino mixing matrix are considerably…

High Energy Physics - Phenomenology · Physics 2016-06-22 Stephen Parke , Mark Ross-Lonergan

We study the prospects of measuring the CKM matrix element $\vert V_{ts}\vert$ at the LHC with the top quarks produced in the processes $p p \to t\bar{t}X$ and $p p \to t/\bar{t} X$, and the subsequent decays $t \to W^+s$ and $\bar{t} \to…

High Energy Physics - Phenomenology · Physics 2014-11-21 Ahmed Ali , Fernando Barreiro , Theodota Lagouri

If the electroweak symmetry is broken by some unspecified strong dynamics, composite fermions may exist with definite transformation properties under SU(2)_L x SU(2)_R/SU(2)_{L+R} and may play a role in giving masses by mixing to all the…

High Energy Physics - Phenomenology · Physics 2010-02-22 Riccardo Barbieri , Gino Isidori , Duccio Pappadopulo

Within the Inert Doublet Model (IDM) there is a viable dark matter candidate. This simple model can provide a strong enough first order phase transition, which is required in order to account for the matter-antimatter asymmetry in the…

High Energy Physics - Phenomenology · Physics 2016-05-31 Cesar Bonilla , Dorota Sokolowska , Neda Darvishi , J. Lorenzo Diaz-Cruz , Maria Krawczyk

Quarks whose left- and right-handed chiral components are both singlets with respect to the SU(2) weak-isospin gauge group, offer interesting physics possibilities beyond the Standard Model (SM) already studied in many contexts. We here…

High Energy Physics - Phenomenology · Physics 2016-09-01 V. Barger , M. S. Berger , R. J. N. Phillips

There are strong arguments favoring the Flavor Democracy hypothesis (or the Democratic Mass Matrix approach) within the Standard Model framework. However, the large mass of the top quark ($m_t >> m_b, m_\tau$) poses an obstacle to the…

High Energy Physics - Phenomenology · Physics 2026-03-06 Burak Dagli , Saleh Sultansoy , Ismail Toy

There are two strong arguments in favor of vector-like leptons and quarks: Flavor Democracy call for them, and E6 GUT predicts existence of iso-singlet quarks and iso-doublet leptons. Vector-like quarks (VLQ) are extensively searched by…

High Energy Physics - Phenomenology · Physics 2022-07-22 Feyza Baspehlivan , Burak Dagli , Osman Emre Delialioglu , Saleh Sultansoy

We update the constraints on the parameters of the quark flavour mixing matrix $V_{CKM}$ in the standard model using the latest experimental and theoretical results as input. We present the 95$\%$ C.L. allowed region of the unitarity…

High Energy Physics - Phenomenology · Physics 2007-05-23 Ahmed Ali , David London

It is proposed that all flavor mixing is caused by the mixing of the three quark and lepton families with vectorlike fermions in 5 + 5-bar multiplets of SU(5). This simple assumption implies that both V_{CKM} and U_{MNS} are generated by a…

High Energy Physics - Phenomenology · Physics 2015-06-11 S. M. Barr , Heng-Yu Chen