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Related papers: A novel route to V_us

200 papers

After the recent high precision determinations of $V_{us}$ and $V_{ud}$, the first row of the CKM matrix shows more than $4\sigma$ deviation from unitarity. Two possible scenarios beyond the Standard Model can be investigated in order to…

High Energy Physics - Phenomenology · Physics 2020-03-18 Benedetta Belfatto , Revaz Beradze , Zurab Berezhiani

I review currently discussed methods to determine the CKM mixing matrix element $|V_{ub}|$ from experimental data. Although the theory of inclusive decays and their spectra has entered a model-independent stage, its predictions are still…

High Energy Physics - Phenomenology · Physics 2007-05-23 Patricia Ball

B --> rho l nu decay is analyzed in the effective theory of heavy quark with infinite mass limit. The matrix element relevant to the heavy to light vector meson semileptonic decays is parametrized by a set of four heavy flavor-spin…

High Energy Physics - Phenomenology · Physics 2014-11-17 W. Y. Wang , Y. L. Wu

The experimental prospects for precise measurements of the leptonic decays B_u -> tau nu / mu nu, B_s -> mu+ mu-, D -> mu nu and D_s -> mu nu / tau nu are very promising. Double ratios involving four of these decays can be defined in which…

High Energy Physics - Phenomenology · Physics 2014-11-21 A. G. Akeroyd , F. Mahmoudi

We perform a global analysis of exclusive hadronic tau decays into one and two mesons using the low-energy limit of the Standard Model Effective Field Theory up to dimension six, assuming left-handed neutrinos. A controlled theoretical…

High Energy Physics - Phenomenology · Physics 2020-03-24 Sergi Gonzàlez-Solís , Alejandro Miranda , Javier Rendón , Pablo Roig

We investigated the origin of the RI'/MOM quark mass under the Landau gauge at the non-perturbative scale, using the chiral fermion with different quark masses and lattice spacings. Our result confirms that such a mass is non-vanishing…

High Energy Physics - Lattice · Physics 2020-03-31 Yi-Bo Yang , Jian Liang , Zhaofeng Liu , Peng Sun

The identification of hadronic tau lepton decays is an important requirement for the LHC physics program, both in terms of standard model measurements and the search for beyond-the-standard-model physics. The ATLAS and CMS algorithms for…

High Energy Physics - Experiment · Physics 2017-09-06 Martin Flechl

The matrix element Vud of the CKM matrix can be determined by two independent measurements on neutron decay: the neutron lifetime tau and the ratio of coupling constants lambda, which is most precisely determined by measurements of the beta…

Nuclear Experiment · Physics 2011-07-21 Bastian Märkisch

We construct new tests of perturbative QCD by considering a hypothetical tau lepton of arbitrary mass, which decays hadronically through the electromagnetic current. We can explicitly compute its hadronic width ratio directly as an integral…

High Energy Physics - Phenomenology · Physics 2009-09-11 S. J. Brodsky , J. R. Pelaez , N. Toumbas

The hadronic vacuum polarisation contributions to the anomalous magnetic moment of the muon, $a_{\mu}^{\rm had, VP}$ are evaluated dispersively via a combination of experimentally measured $e^+e^-\rightarrow {\rm hadrons}$ cross section…

High Energy Physics - Experiment · Physics 2019-03-26 Alexander Keshavarzi

We report on the determination of $|V_{cb}|$ from the comparison of the semileptonic inclusive decay rates of B-- and D--mesons using the heavy quark symmetry of QCD. While the renormalization scale ambiguity does not allow for a reliable…

High Energy Physics - Phenomenology · Physics 2010-11-01 U. Nierste

We studied properties of the strange axial mesons in the relativized quark model. We calculated the $K_1$ decay constant in the quark model and showed how it can be used to extract the $K_1 (^3P_1) - K_1 (^1P_1)$ mixing angle ($\theta_K$)…

High Energy Physics - Phenomenology · Physics 2009-10-28 Harry G. Blundell , Stephen Godfrey , Brian Phelps

We develop a "variational mass" expansion approach, recently introduced in the Gross--Neveu model, to evaluate some of the order parameters of chiral symmetry breakdown in QCD. The method relies on a reorganization of the usual perturbation…

High Energy Physics - Phenomenology · Physics 2014-11-17 C. Arvanitis , F. Geniet , J. -L. Kneur , A. Neveu

We present an extraction of Vcb from a lattice calculation of the B->D* decay matrix elements. We obtain |Vcb| \sqrt{ \frac{ \tauB }{ 1.49 ps } } = 0.037^{+3 \ +5}_{-3 \ -5} from a single parameter fit to the new CLEO data. Email…

High Energy Physics - Lattice · Physics 2010-11-01 Nicholas Hazel

We analyze the numerical determination of the quark mixing factor V(us) from hyperon semileptonic decays. The discrepancies between the results obtained in two previous studies are clarified. Our fits indicate sizeable SU(3) breaking…

High Energy Physics - Phenomenology · Physics 2009-11-11 V. Mateu , A. Pich

We determine the inclusive B --> Xc l nu branching fraction, the CKM matrix element |Vcb|, and other heavy-quark parameters from a simultaneous fit to moments of the hadronic-mass and lepton-energy distributions in semileptonic B-meson…

High Energy Physics - Experiment · Physics 2009-09-29 BABAR Collaboration , B. Aubert , R. Barate , D. Boutigny

The ratio of the CKM quark-mixing matrix elements |Vub|/|Vcb| has been measured using B hadron semileptonic decays. The analysis uses the reconstructed mass M_X of the secondary hadronic system produced in association with an identified…

High Energy Physics - Experiment · Physics 2010-04-08 The DELPHI Collaboration , P. Abreu

As part of a study BSM corrections to leptonic decays of the $B_c$ meson, Tran et al. (arXiv:1801.06927) use the covariant confining quark model (CCQM) to estimate the matrix element of the pseudo-scalar curent between the vacuum and the…

High Energy Physics - Lattice · Physics 2018-06-08 Christine Davies , Craig McNeile

We determine $|V_{cb}|$ from inclusive semileptonic B decays including resummation of supposedly large perturbative corrections, which originate from the running of the strong coupling. We argue that the low value of the BLM scale found…

High Energy Physics - Phenomenology · Physics 2007-05-23 Patricia Ball

We construct a model for dense matter based on low-density nuclear matter properties that exhibits a chiral phase transition and that includes strangeness through hyperonic degrees of freedom. Empirical constraints from nuclear matter alone…

Nuclear Theory · Physics 2022-09-28 Eduardo S. Fraga , Rodrigo da Mata , Savvas Pitsinigkos , Andreas Schmitt