scholarly journals Analyzing new physics in the decays B¯0→D(*)τ−ν¯τ with form factors obtained from the covariant quark model

2016 ◽  
Vol 94 (9) ◽  
Author(s):  
M. A. Ivanov ◽  
J. G. Körner ◽  
C. T. Tran
2015 ◽  
Vol 39 ◽  
pp. 1560113
Author(s):  
A. Liptaj ◽  
S. Dubnička ◽  
A. Z. Dubničková ◽  
M. A. Ivanov

The covariant quark model with infrared confinement (CQM) is a well-suited theoretical framework to describe large variety of hadronic processes, including rare decays of heavy mesons. In this text we focus on the reactions [Formula: see text], which have been recently measured by Refs. 1–4. The measurements include also information about the angular distributions and their significance is given by possible New Physics (NP) effects which are predicted in numerous beyond Standard Model (SM) scenarios. Even with clever choice of experimental observables, a model dependence cannot be fully removed from the theoretical predictions. In this text we present the computation of the [Formula: see text] form factors within the CQM and give results for some of the most commonly used observables ([Formula: see text], [Formula: see text]).


2005 ◽  
Vol 20 (08n09) ◽  
pp. 1785-1790 ◽  
Author(s):  
D. O. RISKA

The chiral quark model posits that pions couple to the axial current of constituent quarks. This chiral pion coupling governs the pion decays of baryon resonances and also implies pion and multipion interactions between the quarks. The qualitative features of this model for the description of pionic decay widths and baryon spectra are outlined. When the covariant quark model wave function for the nucleon is chosen so as to describe the empirical nucleon form factors the pion decay widths of the positive parity resonances are underpredicted. This indicates the presence of significant multiquark components in these resonances.


1999 ◽  
Vol 451 (1-2) ◽  
pp. 187-194 ◽  
Author(s):  
J. Charles ◽  
A. Le Yaouanc ◽  
L. Oliver ◽  
O. Pène ◽  
J.-C. Raynal

2015 ◽  
Vol 39 ◽  
pp. 1560086
Author(s):  
Aidos Issadykov ◽  
Mikhail A. Ivanov ◽  
Sayabek K. Sakhiyev

In the wake of exploring uncertainty in the full angular distribution of the [Formula: see text] caused by the presence of the intermediate scalar [Formula: see text] meson, we perform the straightforward calculation of the [Formula: see text] (S is a scalar meson) transition form factors in the full kinematical region within the covariant quark model. We restrict ourselves by the scalar mesons below 1 GeV: [Formula: see text]. As an application of the obtained results we calculate the widths of the semileptonic and rare decays [Formula: see text], [Formula: see text] and [Formula: see text]. We compare our results with those obtained in other approaches.


2015 ◽  
Vol 91 (7) ◽  
Author(s):  
Aidos Issadykov ◽  
Mikhail A. Ivanov ◽  
Sayabek K. Sakhiyev

2017 ◽  
Vol 17 (2) ◽  
pp. 148-163
Author(s):  
V.V. Andreev ◽  
A.F. Krutov

Mean-square radii and electromagnetic form factors of light mesons are obtained in the framework of Poincare covariant quark model, which is basedon the point form of Poincare invariant quantum mechanics. Calculations areperformed with the use of the requirement of self-consistent description of electroweak properties and masses of pseudoscalar and vector mesons.


2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Lu Zhang ◽  
Xian-Wei Kang ◽  
Xin-Heng Guo ◽  
Ling-Yun Dai ◽  
Tao Luo ◽  
...  

Abstract The semileptonic decay of heavy flavor mesons offers a clean environment for extraction of the Cabibbo-Kobayashi-Maskawa (CKM) matrix elements, which describes the CP-violating and flavor changing process in the Standard Model. The involved form factors where the dynamical information is encoded play an essential role in achieving any conclusive statement. That is, the knowledge of the form factors should be under good control, requiring one to examine more observables in addition to the branching fraction. In this paper, we provide the mean value and the q2-dependent shape for further observables [differential decay distribution (dΓ/dq2), forward-backward asymmetry $$ \left({\mathcal{A}}_{FB}^{ls}\right) $$ A FB ls , longitudinal $$ \left({P}_L^l\right) $$ P L l and transverse $$ \left({P}_T^l\right) $$ P T l polarization of a charged lepton, longitudinal polarization of a vector meson in the final state $$ \left({F}_L^l(V)\right) $$ F L l V , leptonic convexity parameter $$ \left({C}_F^l\right) $$ C F l , and trigonometric moments $$ \left({W}_i^l\right) $$ W i l in the decay of D(s) and B(s) to P/Vl+νl (l = e, μ or τ)], based on the predictions of the relevant form factors from the covariant light-front quark model. P and V denote the pseudoscalar and vector meson, respectively. As a comparison, we find a good agreement with the results from the covariant confining quark model and the relativistic quark model in the literature. As it has been observed that the $$ {P}_L^l $$ P L l and $$ {F}_L^l(V) $$ F L l V are crucial quantities to discriminate various New Physics models, the reexamination of these observables from a different method is also essential and necessary.


1996 ◽  
Vol 365 (1-4) ◽  
pp. 319-326 ◽  
Author(s):  
A Le Yaouanc ◽  
L Oliver ◽  
O Pène ◽  
J.-C Raynal

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