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Sep 23, 2013
09/13

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J. H. Munoz; N. Quintero

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We reanalyzed nonleptonic charmless two-body B decays involving tensor mesons in final state motivated by the disagreement between current experimental information and theoretical predictions obtained in ISGW2 model for some $\mathcal{B}(B \to P(V)T)$ (where $P$, $V$ and $T$ denote a pseudoscalar, a vector and a tensor meson, respectively). We have calculated branching ratios of charmless $B \to PT$ and $B\to VT$ modes, using $B \to T$ form factors obtained in the covariant light-front (CLF)...

Source: http://arxiv.org/abs/0903.3701v1

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Sep 21, 2013
09/13

by
J. H. Munoz; N. Quintero

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In this work we have studied hadronic charmless two-body B decays involving p-wave mesons in final state. We have calculated branching ratios of $B\to AT$ decays (where $A$ and $T$ denotes a $^3P_1$ axial-vector and a tensor meson, respectively), using $B \to T$ form factors obtained in the covariant light-front (CLF) approach, and the full effective Hamiltonian. We have obtained that $\mathcal{B}(B^{0} \to a_{1}^{+}a_{2}^{-}) =42.47 \times10^{-6}$, $\mathcal{B}(B^{+} \to a_{1}^{+}a_{2}^{0}) =...

Source: http://arxiv.org/abs/0905.1526v1

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Sep 18, 2013
09/13

by
I. Bediaga; J. H. Munoz

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We have computed branching ratios of two-body nonleptonic B_c \to X_{c\bar{c}}M decays, where X_{c\bar{c}} is the radially excited charmonium \eta_c(2S) or \psi(2S) meson, and M is a pseudoscalar (P) or a vector (V) or an axial-vector (A(^3P_1)) meson. We have assumed factorization hypothesis and calculated the form factors in the nonrelativistic ISGW2 quark model. We have found that some of these decays have branching ratios of the order of 10^{-3} - 10^{-4}.

Source: http://arxiv.org/abs/1102.2190v2

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Sep 23, 2013
09/13

by
J. H. Muñoz; N. Quintero

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We compute important ratios between decay widths of some exclusive two-body nonleptonic and semileptonic B decays, which could be test of factorization hy- pothesis. We also present a summary of the expressions of the decay widths and differential decay rates of these decays, at tree level, including l = 0 (ground state), l = 1 (orbitally excited) and n = 2 (radially excited) mesons in the fi- nal state. From a general point of view, we consider eight transitions, namely H \rightarrow P, V, S,...

Source: http://arxiv.org/abs/1012.2487v2

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Sep 18, 2013
09/13

by
J. H. Muñoz; N. Quintero

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We present a brief discussion about expressions of decay widths of exclusive nonleptonic and semileptonic B decays at tree level including $l=0$ and $l=1$ mesons in final state. Our analysis is carried out assuming factorization hypothesis and using parametrizations of hadronic matrix elements given in WSB and ISGW quark models. Special interest is focused on dynamics of these processes and several important ratios between decay widths to determine form factors and decay constants are given.

Source: http://arxiv.org/abs/0803.2726v1

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Sep 22, 2013
09/13

by
G. Lopez Castro; J. H. Munoz

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Light tensor mesons (T = a_2, f_2 and K_2^*) can be produced in decays of tau leptons. In this paper we compute the branching ratios of tau --> T pi nu decays by assuming the dominance of intermediate virtual states to model the form factors involved in the relevant hadronic matrix element. The exclusive f_2(1270) pi^- decay mode turns out to have the largest branching ratio, of O(10^-4) . Our results indicate that the contributions of tensor meson intermediate states to the...

Source: http://arxiv.org/abs/1103.2993v2

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Jul 20, 2013
07/13

by
G. Lopez Castro; J. H. Munoz

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Two-body non-leptonic decays of B mesons into PT and VT modes are calculated using the non-relativistic quark model of Isgur et al.. The predictions obtained for $B \to \pi D^*_2, \rho D_2^*$ are a factor of $3\sim 5$ below present experimental upper limits. Interesting patterns are obtained for ratios of B decays involving mesons with different spin excitations and their relevance for additional tests of forms factor models are briefly discussed.

Source: http://arxiv.org/abs/hep-ph/9702238v1

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Sep 19, 2013
09/13

by
G. Lopez Castro; R. Martinez; J. H. Munoz

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Large long-distance standard model effects in FCNC semileptonic D decays can make observable these processes in future measurements. Eventual disagreements in this sector and/or the observation of lepton family violating (LFV) D decays would require an explanatio beyond the SM framework. In this paper we confront present experimental data on leptonic and semileptonic FCNC and LFV D meson decays with a version of the two-Higgs doublet model that allows these effects to occur at tree- level. The...

Source: http://arxiv.org/abs/hep-ph/9804368v1

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Sep 18, 2013
09/13

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D. E. Jaramillo; J. H. Munoz; A. Zepeda

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Some textbooks and reports claim that the Jacobian which arises in the discussion of the Faddeev-Popov method to quantize non-Abelian gauge theories and which is given by the derivative of the gauge fixing conditions over the gauge group parameters, is gauge invariant. Other references however prove the opposite. In this brief report we present a discussion about this matter.

Source: http://arxiv.org/abs/hep-th/9803098v1

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Sep 18, 2013
09/13

by
G. Calderon; J. H. Munoz; C. E. Vera

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We present a systematic study of exclusive charmless nonleptonic two-body B decays including axial-vector mesons in the final state. We calculate branching ratios of B\to PA, VA and AA decays, where A, V and P denote an axial-vector, a vector and a pseudoscalar meson, respectively. We assume naive factorization hypothesis and use the improved version of the nonrelativistic ISGW quark model for form factors in B\to A transitions. We include contributions that arise from the effective \Delta B=1...

Source: http://arxiv.org/abs/0705.1181v2

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Sep 22, 2013
09/13

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G. Lopez Castro; J. H. Munoz; J. Pestieau

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Unstable particles can be consistently described in the framework of quantum field theory. Starting from the full S-matrix amplitudes of B^+ --> (2 pi, 3 pi) l nu decays as examples in the energy region where the rho-omega resonances are dominating, we propose a prescription for the mixing of two quasi `physical' unstable states that differs from the one obtained from the diagonalization of the M -i*Gamma/2 non-hermitian hamiltonian. We discuss some important consequences for CP violation in...

Source: http://arxiv.org/abs/hep-ph/9805201v2

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Sep 23, 2013
09/13

by
G. Calderon; J. H. Munoz; C. E. Vera

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Axial-vector mesons $a_1(1260)$, $f_1(1285)$, $h_1(1170)$, $K_1(1270)$, and $K_1(1400)$ can be produced in semileptonic $\tau\to A P \nu_{\tau}$ decays, where $P$ stands for the pseudoscalar mesons $\pi$ or $K$. We calculate the branching ratios based in a meson dominance model. The exclusive channels $\tau^-\to a_1(1260)^-\pi^0\nu$, $\tau^-\to a_1(1260)^0\pi^-\nu$, and $\tau^-\to h_1(1170)\pi^-\nu$ turn out to be of order ${\cal O}(10^{-3})$, the channel $\tau^-\to f_1(1285)\pi^-\nu$ of order...

Source: http://arxiv.org/abs/1212.1534v2

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Sep 19, 2013
09/13

by
G. Lopez Castro; J. H. Munoz; G. Toledo Sanchez

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We consider the isospin breaking corrections to charmless semileptonic decays of B mesons. Both, the recently measured branching ratios of exclusive decays by the CLEO Collaboration and the end-point reion of the inclusive lepton spectrum in form factor models, can be affected by these corrections. Isospin corrections can affect the determination of |V_ub| from exclusive semileptonic B decays at a level comparable to present statistical uncertainties.

Source: http://arxiv.org/abs/hep-ph/9709266v1

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Sep 22, 2013
09/13

by
G. Lopez Castro; H. B. Mayorga; J. H. Munoz

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We have computed the branching ratios of the exclusive pseudoscalar (vector) + tensor modes that are allowed in the decays of the B_c meson. The dominant spectator and annihilation contributions in those decays are evaluated using the factorization hypothesis. We find that some of these decay channels, such as B_c --> (\rho^-, D_s^{*-}, D_s^{-})\chi_{c2} and B_c^ -->\pi^- \bar{B_{s2}^{*0}}, have branching ratios of the order of 10^{-4}, which seems to be at the reach of forthcoming...

Source: http://arxiv.org/abs/hep-ph/0205273v1

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Sep 19, 2013
09/13

by
H. B. Mayorga; A. Moreno Briceno; J. H. Munoz

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We have obtained the differential decay rate and calculated the branching ratios of the exclusive semileptonic decays $B(D) \to Xl\nu$, where $X$ is a p-wave meson, using the nonrelativistic ISGW quark model. Our results are compared with the predictions of the ISGW2 model. We have computed some branching ratios that were not reported or were reported with 0.00 in this model. For example, we find that $Br(B_c^- \to \bar{B_{s2}^{*0}}l^-\bar{\nu}) = 4.03 \times 10^{-5}$, $Br(B_c^- \to...

Source: http://arxiv.org/abs/hep-ph/0209032v1

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Sep 19, 2013
09/13

by
J. H. Munoz; A. A. Rojas; G. Lopez Castro

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The Cabibbo-suppressed non-leptonic decays of B (and D) mesons to final states involving tensor mesons are computed using the non-relativistic quark model of Isgur-Scora-Grinstein-Wise with the factorization hypothesis. We find that some of these B decay modes, as B --> (K^*, D^*)D^*_2, can have branching ratios as large as 6 x 10^{-5} which seems to be at the reach of future B factories.

Source: http://arxiv.org/abs/hep-ph/9812274v1

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Sep 18, 2013
09/13

by
J. L. Diaz-Cruz; G. Lopez Castro; J. H. Munoz

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We compute isospin corrections to the charmless semileptonic $B \rightarrow V$ transitions arising from $\rho-\omega$ mixing and discuss its relevance in the determination of $V_{ub}$.

Source: http://arxiv.org/abs/hep-ph/9605344v1

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Sep 23, 2013
09/13

by
A. Abd El-Hady; J. H. Muñoz; J. P. Vary

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We make predictions for the exclusive semileptonic and the non-leptonic decay widths of the B_c meson. We evaluate the B_c semileptonic form factors for different decay channels in a relativistic model, and use factorization to obtain the non-leptonic decay widths.

Source: http://arxiv.org/abs/hep-ph/9909406v1