scholarly journals Probing pseudoscalar and scalar mesons in semileptonic decays of $D_s^+$, D+ and D0

2015 ◽  
Vol 30 (02) ◽  
pp. 1550012 ◽  
Author(s):  
Amir H. Fariborz ◽  
Renata Jora ◽  
Joseph Schechter ◽  
M. Naeem Shahid
Keyword(s):  
Semileptonic Decay ◽  
Semileptonic Decays ◽  
Low Energy ◽  
Linear Sigma Model ◽  
Model Parameters ◽  
Final State ◽  
Decay Channels ◽  
Scalar Mesons ◽  
Pseudoscalar Mesons ◽  
Quark Substructure

With the primary motivation of probing the quark substructure of scalar mesons, a generalized linear sigma model for the lowest and the next-to-lowest scalar and pseudoscalar mesons is employed to investigate several semileptonic decays of D mesons. The free parameters of the model (in its leading approximation) have been previously determined from fits to mass spectra and various low-energy parameters. With these fixed parameters, the model has already given encouraging predictions for different low-energy decays and scattering, as well as for semileptonic decay channels of [Formula: see text] that include a scalar meson in the final state. In the present work, we apply the same model (in its leading order with the same fixed parameters) to different semileptonic decay channels of [Formula: see text], D+ and D0. Although these decay channels produce only pseudoscalar mesons in the final states, since various properties of scalar mesons have been used in fixing the model parameters, this study further tests the model and its predictions for the quark substructure of both pseudoscalar as well as scalar mesons. We find that these predictions are in qualitative agreement with experiment.

PROCEDURE FOR GENERATING EQUATIONS IN LINEAR SIGMA MODEL

2011 ◽  
Vol 26 (14) ◽  
pp. 2327-2352 ◽  
Author(s):  
AMIR H. FARIBORZ
Keyword(s):  
Scattering Amplitudes ◽  
Sigma Model ◽  
Point Interaction ◽  
Low Energy ◽  
Linear Sigma Model ◽  
Pseudoscalar Mesons ◽  
Decay Widths ◽  
Symmetry Breaking Term ◽  
The Masses ◽  
Breaking Term

A procedure for implementation of the generating equations in the linear sigma model of low energy QCD is presented. For any explicit symmetry breaking term, this procedure computes the masses of scalar and pseudoscalar mesons as well as various three-point and four-point interaction vertices that are needed in calculation of different decay widths and scattering amplitudes.

TO LEARN LIGHT SCALARS FROM SEMILEPTONIC DECAYS OF HEAVY QUARKONIA

2014 ◽  
Vol 35 ◽  
pp. 1460447 ◽  
Author(s):  
N. N. ACHASOV ◽  
A. V. KISELEV
Keyword(s):  
Dominant Role ◽  
Semileptonic Decays ◽  
Heavy Quarkonia ◽  
Scalar Mesons ◽  
Pseudoscalar Mesons ◽  
Light Scalar

We study the mechanism of production of the light scalar mesons in the [Formula: see text] decays: [Formula: see text], and compare it with the mechanism of production of the light pseudoscalar mesons in the [Formula: see text] decays: [Formula: see text]. We show that the [Formula: see text] transition is negligibly small in comparison with the [Formula: see text] one. As for the the f0(980) meson, the intensity of the [Formula: see text] transition is not more thirty percent from the intensity of the [Formula: see text] ([Formula: see text]) transition. So, the [Formula: see text] decay supports the previous conclusions about a dominant role of the four-quark components in the σ(600) and f0(980) mesons.

scholarly journals UNITARY CHIRAL DYNAMICS IN J/Ψ DECAYS INTO VPP AND THE ROLE OF THE SCALAR MESONS

2005 ◽  
Vol 20 (08n09) ◽  
pp. 1897-1900 ◽  
Author(s):  
L. ROCA ◽  
J. E. PALOMAR ◽  
E. OSET ◽  
H. C. CHIANG
Keyword(s):  
Final State Interaction ◽  
Axial Vector ◽  
Final State ◽  
Mass Distributions ◽  
Scalar Mesons ◽  
Pseudoscalar Mesons ◽  
Unitary Approach ◽  
Chiral Unitary Approach ◽  
Ozi Rule

We make a theoretical study of the J/Ψ decays into ωππ, ϕππ, [Formula: see text] and [Formula: see text] using the techniques of the chiral unitary approach stressing the important role of the scalar resonances dynamically generated through the final state interaction of the two pseudoscalar mesons. We also discuss the importance of new mechanisms with intermediate exchange of vector and axial-vector mesons and the role played by the OZI rule in the J/Ψϕππ vertex, quantifying its effects. The results nicely reproduce the experimental data for the invariant mass distributions in all the channels considered.

scholarly journals PROBING SCALAR MESON STRUCTURES IN χc1 DECAYS INTO PSEUDOSCALAR AND SCALAR

2012 ◽  
Vol 27 (23) ◽  
pp. 1250135 ◽  
Author(s):  
QIAN WANG ◽  
GANG LI ◽  
QIANG ZHAO
Keyword(s):  
Quark Model ◽  
Scalar Meson ◽  
Branching Ratios ◽  
Decay Process ◽  
Final State ◽  
Great Opportunity ◽  
Scalar Mesons ◽  
Pseudoscalar Mesons ◽  
Parametrization Scheme ◽  
Light Mesons

We evaluate the decay branching ratios of χc1 → PS, in a quark model parametrization scheme, where P and S stand for pseudoscalar and scalar meson, respectively. An interesting feature of this decay process is that the [Formula: see text] annihilate via the pQCD hair-pin diagram is supposed to be dominant. Hence, this decay process should be sensitive to the quark components of the final-state light mesons, and would provide a great opportunity for testing the mixing relations among the scalar mesons, i.e. f0(1370), f0(1500) and f0(1710), by tagging the final state pseudoscalar mesons.

scholarly journals Two-body decay widths of lowest lying and next-to-lowest lying scalar and pseudoscalar mesons in generalized linear sigma model

2015 ◽  
Vol 30 (22) ◽  
pp. 1550134 ◽  
Author(s):  
S. Mohammad Zebarjad ◽  
Soodeh Zarepour
Keyword(s):  
Energy Region ◽  
Sigma Model ◽  
Low Energy ◽  
Experimental Results ◽  
Linear Sigma Model ◽  
Pseudoscalar Mesons ◽  
Decay Widths

Two-body decay widths of lowest lying and next-to-lowest lying scalar and pseudoscalar mesons are studied in generalized linear sigma model (GLSM) of low-energy QCD. This model which considers mixing between “two-quark” and “four-quark” chiral nonets has been employed to investigate various decays and scatterings in low-energy region of QCD. In this paper, [Formula: see text] and [Formula: see text] are obtained and it is shown that two-body decay widths of lowest lying mesons are well predicted by this model while for the next-to-lowest lying mesons, only some of the decay widths agree with the experimental results. We have compared the predicted decay widths in GLSM with the results obtained in single nonet linear sigma model (SNLSM) to indicate that chiral nonet mixing greatly improves the predictions of SNLSM for decay widths.

scholarly journals Charmed and bottomed hadronic cross sections from a statistical model

2020 ◽  
Vol 56 (9) ◽  
Author(s):  
Gábor Balassa ◽  
György Wolf
Keyword(s):  
Statistical Model ◽  
Energy Range ◽  
Cross Sections ◽  
Heavy Quarks ◽  
Open Charm ◽  
Low Energy ◽  
Final State ◽  
Proton Antiproton ◽  
Proton Proton

Abstract In this work, we extended our statistical model with charmed and bottomed hadrons, and fit the quark creational probabilities for the heavy quarks, using low energy inclusive charmonium and bottomonium data. With the finalized fit for all the relevant types of quarks (up, down, strange, charm, bottom) at the energy range from a few GeV up to a few tens of GeV’s, the model is now considered complete. Some examples are also given for proton–proton, pion–proton, and proton–antiproton collisions with charmonium, bottomonium, and open charm hadrons in the final state.

scholarly journals The low-energy effective theory of axions and ALPs

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Martin Bauer ◽  
Matthias Neubert ◽  
Sophie Renner ◽  
Marvin Schnubel ◽  
Andrea Thamm
Keyword(s):  
High Energy ◽  
New Physics ◽  
Mass Scale ◽  
Low Energy ◽  
Effective Theory ◽  
Loop Order ◽  
Flavor Changing ◽  
Effective Lagrangian ◽  
Anomalous Dimensions ◽  
Pseudoscalar Mesons

Abstract Axions and axion-like particles (ALPs) are well-motivated low-energy relics of high-energy extensions of the Standard Model, which interact with the known particles through higher-dimensional operators suppressed by the mass scale Λ of the new-physics sector. Starting from the most general dimension-5 interactions, we discuss in detail the evolution of the ALP couplings from the new-physics scale to energies at and below the scale of electroweak symmetry breaking. We derive the relevant anomalous dimensions at two-loop order in gauge couplings and one-loop order in Yukawa interactions, carefully considering the treatment of a redundant operator involving an ALP coupling to the Higgs current. We account for one-loop (and partially two-loop) matching contributions at the weak scale, including in particular flavor-changing effects. The relations between different equivalent forms of the effective Lagrangian are discussed in detail. We also construct the effective chiral Lagrangian for an ALP interacting with photons and light pseudoscalar mesons, pointing out important differences with the corresponding Lagrangian for the QCD axion.

scholarly journals Study of Rare Mesonic Decays Involving Di-Neutrinos in Their Final State

2018 ◽  
Vol 2018 ◽  
pp. 1-20
Author(s):  
Azeem Mir ◽  
Farida Tahir ◽  
Shakeel Mahmood ◽  
Shi- Hai Dong
Keyword(s):  
Branching Fractions ◽  
New Physics ◽  
Supersymmetric Model ◽  
Final State ◽  
Yukawa Couplings ◽  
Leptonic Decays ◽  
Pseudoscalar Mesons ◽  
Theoretical Predictions ◽  
Minimal Supersymmetric Model

We have studied phenomenological implication of R-parity violating (Rp) Minimal Supersymmetric Model (MSSM) via analyses of pure leptonic (M→νν¯) and semileptonic decays of pseudoscalar mesons (M→Xνν¯). These analyses involve comparison between theoretical predictions made by Rp MSSM and the Standard Model (SM) with the experimental results like branching fractions (Br) of the said process. We have found, in general, that Rp contribution dominates over the SM contribution, i.e., by a factor of 10 for the pure leptonic decays of KL,S and by 102 and 104 in case of Bs and Bd, respectively. Furthermore, the limits obtained on Rp Yukawa couplings (λαkβ′λαkγ′⁎) by using Br  (M→Xνν¯) are used to calculate Br  (M→νν¯). This demonstrates the role of Rp MSSM as a viable model for the study of new physics contribution in rare decays at places like Super B factories, KOTO (J-PARC) and NA62 at CERN.

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