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K. Azizi

Publications and source records attributed to K. Azizi.

At least 253 records · Page 14Linked to original sources
arXiv2014

More about the $B$ and $D$ mesons in nuclear matter

We calculate the shifts in decay constants of the pseudoscalar $B$ and $D$ mesons in nuclear medium in the frame work of QCD sum rules. We write those shifts in terms of the $B-N$ and $D-N$ scattering lengths and an extra phenomenological parameter entered to calculations. Computing an appreciate forward scattering correlation function, we derive the QCD sum rules for the $B-N$ and $D-N$ scattering lengths and the extra phenomenological parameter in terms of various operators in nuclear medium. We numerically find the values of the shifts in the decay constants compared to their vacuum values. Using the sum rules obtained, we also determine the shifts in the masses of these particles due to nuclear matter and compare the results obtained with the previous predictions in the literature.

hep-ph↗
arXiv2014

Properties of nucleon in nuclear matter: once more

We calculate the mass and residue of the nucleon in nuclear matter in the framework of QCD sum rules using the nucleon's interpolating current with an arbitrary mixing parameter. We evaluate the effects of the nuclear medium on these quantities and compare the obtained results with the existing theoretical predictions. The results are also compared with those obtained in vacuum to find the shifts in the quantities under consideration. Our calculations show that these shifts in the mass and residue are about $32\%$ and $15\%$, respectively.

hep-ph↗
arXiv2014

Properties of triply heavy spin--3/2 baryons

The masses and residues of the triply heavy spin--3/2 baryons are calculated in framework of the QCD sum rule approach. The obtained results are compared with the existing theoretical predictions in the literature.

hep-ph↗
arXiv2014

Thermal properties of $D_2^*(2460)$ and $D_{s2}^*(2573)$ tensor mesons using QCD sum rules

We investigate the masses and decay constants of the heavy-light $D_2^*(2460)$ and $D_{s2}^*(2573)$ tensor mesons in the framework of thermal QCD sum rules. Taking into account the additional operators arising at finite temperature, we evaluate the Wilson expansion for the two-point correlation function associated with these mesons. We observe that the values of the masses and decay constants decrease considerably at near to the critical temperature. The decay constants attain roughly to $25\%$ of their values in vacuum, while the masses decrease about $39\%$ and $37\%$ in $D_2^*$ and $D_{s2}^*$ channels, respectively.

hep-ph↗
arXiv2013

Properties of $D_{s2}^*(2573)$ charmed-strange tensor meson

The mass and current coupling constant of the $D_{s2}^* (2573)$ charmed-strange meson is calculated in the framework of two-point QCD sum rule approach. Although the quantum numbers of this meson is not exactly known, its width and decay modes are consistent with $I(J^P)=0(2^+)$, which we consider to write the interpolating current used in our calculations. Replacing the light strange quark with up or down quark we also compare the results with those of $D_{2}^*$ charmed tensor meson and estimate the order of SU(3) flavor symmetry violation.

hep-ph↗
arXiv2013

Investigation of the $D^{\ast}_{s}D_{s} η^{(\prime)}$ and $B^{\ast}_{s}B_{s} η^{(\prime)}$ vertices via QCD sum rules

The strong coupling constants among mesons are very important quantities as they can provide useful information on the nature of strong interaction among hadrons as well as the QCD vacuum. In this article, we investigate the strong vertices of the $D^{\ast}_{s}D_{s} η^{(\prime)}$ and $B^{\ast}_{s}B_{s} η^{(\prime)}$ in the framework of the QCD sum rule approach choosing the $η$ or $D_{s} (B_{s})$ meson as an off-shell state. We obtain the results $g_{D_s^*D_sη}=(1.46\pm 0.30)GeV^{-1}$, $g_{D_s^*D_sη^{\prime}}=(0.74\pm 0.16)GeV^{-1}$, $g_{B_s^*B_sη}=(5.29\pm 1.06)GeV^{-1}$ and $g_{B_s^*B_sη^{\prime}}=(2.29\pm 0.48)GeV^{-1}$ for the strong coupling constants under consideration, which can be checked in future experiments.

hep-ph↗
arXiv2013

Analysis of the semileptonic $Λ_b\rightarrow Λ\ell^+ \ell^-$ transition in topcolor-assisted technicolor (TC2) model

We comparatively analyze the flavor changing neutral current process of the $Λ_b \rightarrow Λ\ell^+ \ell^-$ in the standard model as well as topcolor-assisted technicolor model using the form factors calculated via light cone QCD sum rules in full theory. In particular, we calculate the decay width, branching ratio and lepton forward-backward asymmetry related to this decay channel. We compare the results of the topcolor-assisted technicolor model with those of the standard model and debate how the results of the topcolor-assisted technicolor model depart from the standard model predictions. We also compare our results on the differential branching ratio with recent experimental data provided by CDF and LHCb Collaborations.

hep-ph↗
arXiv2013

Mass and Decay Constant of the $D_2^*(2460)$ Tensor Meson

We calculate the mass and decay constant of the $D_2^*(2460)$ tensor meson in the framework of QCD sum rules. The obtained result on the mass is compatible with the experimental data. Our prediction on the decay constant can be checked in experiment.

hep-ph↗
arXiv2013

Investigation of the semileptonic transition of the $B$ into the orbitally excited charmed tensor meson

The transition form factors of the semileptonic $B \rightarrow D_2^*(2460)\ell\barν\,\,\,\,(\ell=τ,μ,e)$ decay channel are calculated within the framework of the three-point QCD sum rules. The fit functions of the form factors are then used to estimate the total decay width and branching ratio of this transition. The order of branching ratio shows that this channel can be detected at LHCb.

hep-ph↗
arXiv2013

Analysis of the radiative $Λ_b\rightarrow Λγ$ transition in SM and scenarios with one or two universal extra dimensions

We investigate the radiative process of the $Λ_b\rightarrow Λγ$ in the standard model as well as models with one or two compact universal extra dimensions. Using the form factors entered to the low energy matrix elements, calculated via light cone QCD in full theory, we calculate the total decay width and branching ratio of this decay channel. We compare the results of the extra dimensional models with those of the standard model on the considered physical quantities and look for the deviations of the results from the standard model predictions at different values of the compactification scale (1/R).

hep-ph↗
arXiv2013

Semileptonic Transition of $Σ_b \rar Σμ^+ μ^-$ in Family Non-universal $Z^\prime$ Model

Using newly available form factors obtained from light cone QCD sum rules in full theory, we study the flavor changing neutral current transition of $Σ_b \rar Σμ^+ μ^-$ decay in the family non-universal $Z^\prime$ model. In particular, we evaluate the differential branching ratio, forward-backward asymmetry as well as some related asymmetry parameters and polarizations. We compare the obtained results with the predictions of the standard model and discuss the sensitivity of the observables under consideration to family non-universal $Z^\prime$ gauge boson. The order of differential branching ratio shows that this decay mode can be checked at LHC in near future.

hep-ph↗
arXiv2013

Investigation of the $B_c\rightarrow χ_{c2} l \barν $ transition via QCD sum rules

We calculate the transition form factors of the semileptonic $B_c\rightarrow χ_{c2} l \barν $ in the framework of QCD sum rules taking into account the two-gluon condensate corrections. Using the obtained results of form factors we estimate the decay widths and branching ratios related to this transition at all lepton channels. A comparison of the obtained results with the predictions of other non-perturbative approaches are also made. The orders of branching ratios for different lepton channels indicate that the $B_c\rightarrow χ_{c2} l \barν $ transition can be studied at LHC using the collected or future data.

hep-ph↗
arXiv2013

Analysis of $γ^\ast Λ\to Σ^0$ transition in QCD

The $γ^\ast Λ\to Σ^0$ transition form factors are investigated within the light--cone QCD sum rules method. Using the most general form of the interpolating current of $Σ^0$ baryon and the distribution amplitudes of $Λ$ baryon we calculate the $Q^2$ dependence of the electromagnetic form factors. Our result are compared with the predictions of the covariant spectator quark model.

hep-ph↗
arXiv2013

Electromagnetic form factors of octet baryons in QCD

The electromagnetic form factors of octet baryons are estimated within light cone QCD sum rules method, using the most general form of the interpolating current for baryons. A comparison of our predictions on the magnetic dipole and electric form factors with the results of other approaches is performed.

hep-ph↗
arXiv2013

Masses and Residues of the Triply Heavy Spin-1/2 Baryons

We calculate the masses and residues of the triply heavy spin--1/2 baryons using the most general form of their interpolating currents within the QCD sum rules method. We compare the obtained results with the existing theoretical predictions in the literature.

hep-ph↗
arXiv2012

Rare Radiative $B_{c}\rightarrow D_{s1}(2460)γ$ Transition in QCD

We investigate the radiative $B_{c} \to D_{s1} γ$ transition in the framework of QCD sum rules. In particular, we calculate the transition form factors responsible for this decay in both weak annihilation and electromagnetic penguin channels using the quark condensate, mixed and two-gluon condensate diagrams as well as propagation of the soft quark in the electromagnetic field as non-perturbative corrections. These form factors are then used to estimate the branching ratios of the channels under consideration. The total branching ratio of the $B_{c} \to D_{s1} γ$ transition is obtained to be in order of $10^{-5}$, and the dominant contribution comes from the weak annihilation channel.

hep-ph↗