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V. Bashiry

Publications and source records attributed to V. Bashiry.

36 records · Page 2Linked to original sources
arXiv2008

The Effects of Fourth Generation on the double Lepton Polarization in B \rar K \ell^+ \ell^- decay

This study investigates the influence of the fourth generation quarks on the double lepton polarizations in B \rar K \ell^+ \ell^- decay. Taking |V_{t's}V_{t'b}|\sim \{0.01-0.03\} with phase about 100^\circ, which is consistent with the b\to s\ell^+\ell^- rate and the B_s mixing parameter Delta m_{B_s}$, we obtain that the double lepton(muon and tau) polarizations are quite sensitive to the existence of fourth generation. It can serve as a good tool to search for new physics effects, precisely, to indirect search for the fourth generation quarks(t', b').

hep-ph↗
arXiv2007

QCD sum rules analysis of the rare radiative Bc -> D*_s gamma decay

In this work, the radiative Bc -> D*_s gamma decay is investigated in the framework of QCD sum rules. The transition form factors responsible for the decay are calculated. The branching ratio for this decay is estimated to be order of 10^-5 which can be measurable at LHC.

hep-ph↗
arXiv2007

Analysis of the B --> π\ell^+ \ell^- Decay in the Standard Model with Fourth Generation

We investigate the influence of the fourth generation quarks on the branching ratio and the CP-asymmetry in B -->π\ell^+ \ell^- decay. Taking the |V_{t'd}V_{t'b}| ~ 0.001 with phase about 10 degree, which is consistent with the sin2ϕ_1 of the CKM and the B_d mixing parameter Δm_{B_d}, we obtain that for both muon and tau channels the branching ratio, the magnitude of CP-asymmetry and lepton polarization depict strong dependency on the 4th generation quarks mass and mixing parameters. These results can serve as a good tool to search for new physics effects, precisely, to search for the fourth generation quarks($t', b')$ via its indirect manifestations in loop diagrams.

hep-ph↗
arXiv2007

Double Lepton Polarization in $Λ_b -->Λl^+ l^-$ Decay in the Standard Model with Fourth Generations Scenario

This study investigates the influence of the fourth generation quarks on the double lepton polarizations in Λ_b --> Λ\ell^+ \ell^- decay by taking |V^\ast_{t's}V_{t'b}|= 0.005,0.01,0.02,0.03 with phase \{60^\circ,90^\circ,120^\circ\}. We will try to obtain a constrain on the mass of the 4th generation top like quark t', which is consistent with the $b--> s\ell^+\ell^- rate . With the above mentioned parameters, we will try to show that the double lepton(muon, tau) polarizations are quite sensitive to the existence of fourth generation. It can serve as a good tool to search for new physics effects, precisely, to search for the fourth generation quarks(t', b') via its indirect manifestations in loop diagrams.

hep-ph↗
arXiv2007

Double Lepton Polarization Forward--Backward Asymmetries in B \rar K^\ast \ell^+ \ell^- Decay in the SM4

This study examines the influence of the fourth generation quarks on the double lepton polarizations forward--backward asymmetries in B \rar K^\ast \ell^+ \ell^- decay. We obtain that for both (muon, tau) channels the magnitude and the sign of the differential forward--backward asymmetries and the magnitude of the average forward--backward asymmetries are quite sensitive to the 4th generation quarks mass and mixing parameters. It can serve as a good tool to search for new physics effects, precisely, to search for the fourth generation quarks(t', b') via its indirect manifestations in the loop diagrams.

hep-ph↗
arXiv2007

The Effects of Fourth Generation on the Total Branching Ratio and the Lepton Polarization in $Λ_b \rar Λ\ell^+ \ell^-$ decay

This study investigates the influence of the fourth generation quarks on the total branching ratio and the single lepton polarizations in Λ_b --> Λ\ell^+ \ell^- decay. Taking $|V_{t's}V_{t'b}| {0.01-0.03} with phase just below $90^\circ$, which is consistent with the b\to s\ell^+\ell^- rate and the B_s mixing parameter Δm_{B_s}, we obtain that the total branching ratio and the single lepton(μ, τ) polarizations are quite sensitive to the existence of fourth generation. It can serve as a good tool to search for new physics effects, precisely, to search for the fourth generation quarks(t', b').

hep-ph↗
arXiv2007

B^-_c->η' \ell^- \barν decay and lepton polarization asymmetry

In this paper we study the lepton polarization asymmetry for the simileptonic OZI-forbidden annihilation B^-_c->η' \ell^- \barν decay where \ell=μ, τ. Our results show that the branching ratio turn out to be of order 10^{-4}. Beside, we find that longitudinal, transversal and normal components of lepton polarizations can be measured for both μand τdecay modes in the future experiments at the LHC.

hep-ph↗
arXiv2006

CP-Violation in b \to s \ell^{+} \ell^{-} transition Beyond the Standard Model

In this study the CP-asymmetry in the b \to s \ell^{+} \ell^{-} transition was investigated in minimal extension of the Standard Model where C_{9}^{eff} receives an extra weak phase due to the new physics effects. We observed that CP-Violation asymmetry can be measurable in the framework of scenario mentioned above.

hep-ph↗
arXiv2005

Exclusive (B -> rho l^+ l^-) decay and Polarized lepton pair forward--backward asymmetries

The polarized lepton pair forward-backward asymmetries in (B -> rho l^+ l^-) decay using a general, model independent form of the effective Hamiltonian is studied. The general expression for nine double-polarization forward-backward asymmetries are calculated. The study of the forward-backward asymmetries of the doubly-polarized lepton pair proves to be very useful tool in looking for new physics beyond the standard model.

hep-ph↗
arXiv2004

Polarized forward-backward asymmetries of leptons in (B_s -> l^+ l^- gamma) decay

Polarized forward-backward asymmetries in the (B_s -> l^+ l^- gamma) decay are calculated using the most general, model independent form of the effective Hamiltonian, including all possible forms of interactions. The dependencies of the asymmetries on new Wilson coefficients are investigated. The detectability of the asymmetries at LHC is discussed.

hep-ph↗
arXiv2004

Double-lepton polarizations in (B -> l^+ l^- gamma) decay

Double-lepton polarization asymmetries in the (B -> l^+ l^- gamma) decay are calculated using the most general, model independent form of the effective Hamiltonian including all possible forms of the interaction. The dependencies of the asymmetries on new Wilson coefficients are investigated. The detectability the averaged double-lepton polarization asymmetries at LHC is also discussed.

hep-ph↗
arXiv2004

Double-lepton polarization asymmetries in Lambda_b -> Lambda l^+ l^- decay

Double-lepton polarization asymmetries in (Lambda_b -> Lambda l^+ l^-) decay are calculated using a general, model independent form of the effective Hamiltonian. The sensitivities of these asymmetries to the new Wilson coefficients are studied in detail. Furthermore, the correlations between averaged double-lepton polarization asymmetry and branching ratio are analyzed. It is shown that there exist certain regions of the new Wilson coefficients where new physics can be established by measuring the double-lepton polarization asymmetries only.

hep-ph↗
arXiv2004

Forward-backward asymmetries in (Lambda_b -> Lambda l^+ l^-) decay beyond the standard model

We study the doubly-polarized lepton pair forward-backward asymmetries in (Lambda_b -> Lambda l^+ l^-) decay using a general, model independent form of the effective Hamiltonian. We present the general expression for nine double-polarization forward-backward asymmetries. It is observed that, the study of the forward-backward asymmetries of the doubly-polarized lepton pair is a very useful tool for establishing new physics beyond the standard model. Moreover, the correlation between forward-backward asymmetry and branching ratio is investigated. It is shown that there exist certain certain regions of the new Wilson coefficients where new physics can be established by measuring the polarized forward-backward asymmetry only.

hep-ph↗
arXiv2004

Polarized lepton pair forward-backward asymmetries in (B -> K^* l^+ l^-) decay beyond the standard model

We study the polarized lepton pair forward-backward asymmetries in (B -> K^* l^+ l^-) decay using a general, model independent form of the effective Hamiltonian. We present the general expression for nine double-polarization forward-backward asymmetries. It is shown that, the study of the forward-backward asymmetries of the doubly-polarized lepton pair is a very useful tool for establishing new physics beyond the standard model.

hep-ph↗
arXiv2004

Double-lepton polarization asymmetries in the (B -> K l^+ l^-) decay beyond the Standard Model

General expressions for the double-lepton polarizations in the (B -> K l^+ l^-) decay are obtained, using model independent effective Hamiltonian, including all possible interactions. Correlations between the averaged double-lepton polarization asymmetries and the branching ratio, as well as, the averaged single-lepton polarization asymmetry are studied. It is observed that, study of the double-lepton polarization asymmetries can serve as a good test for establishing new physics beyond the Standard Model.

hep-ph↗
arXiv2004

Lepton Polarization Asymmetry in B\to\ell^{+}\ell^{-} decay Beyond the Standard Model

The lepton polarization asymmetry in the B\to\ell^{+}\ell^{-} decay, when one of the leptons is polarized, is investigated using the most general form of the effective Hamiltonian. The sensitivity of the asymmetry to the new Wilson coefficients is studied.Moreover, correlations between the lepton polarization asymmetry and the branching ratio is studied. It is observed that, there are not exist such regions of new Wilson coefficients, which the value of branching ratio coincides with SM result while the lepton polarization does not, i.e new physics effects can be established by studying lepton polarization only.

hep-ph↗