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Dang Van Soa

Publications and source records attributed to Dang Van Soa.

18 recordsLinked to original sources

Investigation of the $l^{-}l^{+}ν\overlineν$ final state at multi-TeV muon colliders through the exclusive decay of ZZ/WW gauge bosons in the Randall-Sundrum model

An attempt is made to present the effect of the exclusive decay of ZZ/WW gauge bosons at high energy colliders in the Randall-Sundrum (RS) model. In this paper, we investigate the $l^{-}l^{+}ν\overlineν$ final state at muon-TeV colliders through the exclusive decay of ZZ/WW gauge bosons in detail. The result shows that with fixed collision energies, cross-sections for $l^{-}l^{+}ν\overlineν$ production in final state depend strongly on the parameters of the unparticle physics, muon polarization coefficients, parameters on anomalous couplings and also KK-graviton propagators. With the benchmark background $(Λ_{U}, d_{U})$ $= (1 $TeV$, 1.9)$, the total cross-sections achieve the maximum value when both of muon beams polarize left or right. In case of the different polarization, the cross section increases as the collision energy increases. The numerical evaluation shows that the cross-section for $l^{-}l^{+}ν\overlineν$ final state through the exclusive decay of WW charged bosons is much larger than that of ZZ neutral bosons under the same conditions. With the contribution of new physics in the RS model, the effect is greatly enhanced and the cross-sections for the production of $l^{-}l^{+}ν\overlineν$ final state can be measured in the future muon collisions.

hep-ph

The contribution of new physics on the exclusive W boson hadronic decays in the final state at muon colliders in the Randall-Sundrum model

An attempt is made to present the effect of new physics in the exclusive decays of W boson at high energy colliders in the Randall-Sundrum (RS) model. By using Feynman diagram techniques we have evaluated the influence of the scalar unparticle, polarization and anomalous couplings on the exclusive W boson hadronic decays of $W^{\pm} \rightarrow π^{\pm}γ$, $W^{\pm} \rightarrow K^{\pm}γ$ and $W^{\pm} \rightarrow ρ^{\pm}γ$ at the high energy muon colliders in the RS model. The result shows that with fixed collision energies, the total cross-section for hadronic productions in the final state depends strongly on the parameters of the unparticle physics, muon beam polarizes and also anomalous couplings. With a center-of-mass energy of 10 TeV, the total cross-sections achieve the maximum value when the benchmark signal point as $(Λ_{U}, d_{U})$ $= (1 \text{TeV}, 1.9)$ and the polarization coefficient as $(P_{μ^{-}}, P_{μ^{+}} )= (1,1)$. The numerical evaluation shows that with the contribution of new physics in the RS model, the effect is greatly enhanced at high energy colliders. The statistical significance can reach $1σ- 7σ$ in case of using the W branching ratio at the experimental bounds of $\mathcal{O} (10^{-6})$. To clarify the contribution of new physics, we use a $χ^{2}$ analysis with systematic errors to determine the sensitivities of the new contributions. The result indicates that the sensitivities on the anomalous coupling $WWγ$ are much larger than that on the anomalous coupling $WW Z$ under the same conditions.

hep-ph

Axion-like particle production in SUSY DFSZ-like model at the ILC and LHeC

We present an analysis of axion-like particle (ALP) production in SUSY DFSZ-like model at the ILC and LHeC. We calculate the differential and total cross-sections in $γ^{*}e^{-}$ and $e^{-}e^{+}$ collisions including the effect of the scattering angle, the polarization coefficients, the energy and the ALP mass. From that, we compare the total cross-sections at the LHeC to those at the ILC. To predict the existence of ALP signals, we evaluate the significance level of the final state followed by ALP decaying di-photon at the LHeC and the ILC.

hep-ph

Dark symmetry implication for right-handed neutrinos

We argue that the long-standing issues of neutrino mass and dark matter can be manifestly solved in a dark gauge symmetry $U(1)_D$ that transforms nontrivially only for three right-handed neutrinos $ν_{1,2,3R}$ -- the counterparts of known left-handed neutrinos. This theory assigns $ν_{1,2,3R}$ dark charge to be $D=0$, $-1$, and $+1$, respectively, in order for anomaly cancelation. Additionally, it imposes an inert Higgs doublet $η$ and two Higgs singlets $ξ,ϕ$ with dark charge $D=+1$, $-1$, and $+2$, respectively. That said, the dark symmetry is broken by $ϕ$ (by two units) down to a dark parity $P_D=(-1)^D$, for which $ν_{2,3R}$ and $η,ξ$ are odd, whereas all other fields are even due to $D=0$. The lightest of these odd fields is stabilized by $P_D$, responsible for dark matter. Neutrino masses are generated by a scotoseesaw scheme, in which the seesaw part is mediated by $ν_{1R}$, while the scotogenic part is mediated by $ν_{2,3R}$, for which the hierarchy of atmospheric and solar neutrino mass splittings is explained.

hep-ph

Investigation of the scalar unparticle and anomalous couplings at muon colliders in final states with multiple photons in the Randall- Sundrum model

The influence of the scalar unparticle and anomalous couplings at muon colliders in final states with multiple photons in the Randall-Sundrum model is evaluated in detail. The results indicate that with fixed collision energies, the total cross-sections for the production of multiple photons depend strongly on the polarization of the muon beams, the parameters of unparticle physics (the scaling dimension $d_{U}$, operator $\mathcal{O}_{U}$, the energy scale $Λ_{U}$) and also the strength of anomalous couplings. Numerical evaluation shows that the cross-sections for the production of four photons in finale states with the contribution of scalar anomalous couplings are much larger than that of the unparticle under the same conditions. In the Higgs-radion mixing, the cross sections achieve the maximum value at the radion-dominated state, $m_ϕ = 125$ GeV, in which the cross-section is much enhanced and can be measurable in current experiments.

hep-ph

The influence of the scalar unparticle on the W-pair production at ILC in the Randall Sundrum model

An attempt is made to present the contribution of the scalar unparticle on some scattering processes in the Randall - Sundum (RS) model. We have evaluated the contribution of the scalar unparticle on the W - pair production cross-sections at International Linear Colliders (ILC). The results indicate that at the low values of the scaling dimension and the bounds on scale $Λ_{U}$ are around few TeV, the cross-sections are much enhanced, which is quite comparable with the W-production in the standard model and hence it is worthwhile to explore in future colliders.

hep-ph

Neutrino mass and dark matter from an approximate $B-L$ symmetry

We argue that neutrino mass and dark matter can arise from an approximate $B-L$ symmetry. This idea can be realized in a minimal setup of the flipped 3-3-1 model, which discriminates lepton families while keeping universal quark families and uses only two scalar triplets in order for symmetry breaking and mass generation. This proposal contains naturally an approximate non-Abelian $B-L$ symmetry which consequently leads to an approximate matter parity. The approximate symmetries produce small neutrino masses in terms of type II and III seesaws and may make dark matter long lived. Additionally, dark matter candidate is either unified with the Higgs doublet by gauge symmetry or acted as an inert multiplet. The Peccei-Quinn symmetry is discussed. The gauge and scalar sectors are exactly diagonalized. The signals of the new physics at colliders are examined.

hep-ph

Bilepton contributions to the neutrinoless double beta decay in the economical 3-3-1 model

Possible contributions of the bilepton to the neutrinoless double beta $(ββ)_{0ν}$ decay in the economical 3-3-1 model are discussed. We show that the $(ββ)_{0ν}$ decay in this model is due to both sources--Majorana $ _{L}$ and Dirac $ _{D}$ neutrino masses. If the mixing angle between charged gauge bosons, the standard model $W$ and bilepton $Y$, is in range of the ratio of neutrino masses $ _{L}/< M_ν>_{D}$, both the Majorana and Dirac masses simultaneously give contributions dominant to the decay. As results, constraints on the bilepton mass are also given.

hep-ph

Photon - Axion Conversion Cross Sections in a Resonant Cavity

Photon - axion conversions in the resonant cavity with the lowest mode are considered in detail by the Feynman diagram method. The differential cross sections are presented and numerical evaluations are given. It is shown that there is a resonant conversion for the considered process, in which the conversion cross sections are much larger than those of the wave guide in the same conditions. Some estimates for experimental conditions are given from our results.

hep-ph

Study of the singly charged Higgs in the economic at 3-3-1 model at e^+e^ colliders

The $\mathrm {SU}(3)_C\otimes \mathrm {SU}(3)_L \otimes {\mathrm U}(1)_X$ gauge model with two Higgs triplets (the economical 3-3-1 model) are presented. This model predicts a new singly-charged Higgs bosons $H_2^\pm$, namely a scalar bilepton (a particle of lepton number 2) with mass proportional to the bilepton mass $M_Y$ through the coefficient $\la_4$. Pair production of $H_2^\pm$ at high energy $e^+ e^-$ colliders with polarization of $e^+$, $e^-$ beams was studied in detail. Numerical evaluation shows that if Higgs mass is not too heavy and at high degree of polarization then the reaction can give observable cross section in future colliders. The reaction $e^+ e^- \to H^{-}_2W^+ $ is also examined. Based on the result, it shows that production cross sections of $H^{-}_2W^+$ are very small, much below pair production of $H^{\pm}_2$, so that the direct production of them is in general not expected to lead to easily observable signals in $e^+e^-$ annihilation.

hep-ph

Higgs-gauge boson interactions in the economical 3-3-1 model

Interactions among the standard model gauge bosons and scalar fields in the framework of SU(3)_C X SU(3)_L X U(1)_X gauge model with minimal (economical) Higgs content are presented. From these couplings, all scalar fields including the neutral scalar $h$ and the Goldstone bosons can be identified and their couplings with the usual gauge bosons such as the photon, the charged $W^\pm$ and the neutral $Z$, without any additional condition, are recovered. In the effective approximation, full content of scalar sector can be recognized. The CP-odd part of Goldstone associated with the neutral non-Hermitian bilepton gauge boson $G_{X^0}$ is decouple, while its CP-even counterpart has the mixing by the same way in the gauge boson sector. Masses of the new neutral Higgs boson $H^0_1$ and the neutral non-Hermitian bilepton $X^0$ are dependent on a coefficient of Higgs self-coupling ($λ_1$). Similarly, masses of the singly-charged Higgs boson $H_2^\pm$ and of the charged bilepton $Y^\pm$ are proportional through a coefficient of Higgs self-interaction ($λ_4$). The hadronic cross section for production of this Higgs boson at the LHC in the effective vector boson approximation is calculated. Numerical evaluation shows that the cross section can exceed 260 $fb$.

hep-ph

Production and Decay of Saxion in $e^+e^-$ Collisions

The production of saxion in $e^{+}$$e^{-}$ collider and the saxion decay into two photons were calculated in detail. Based on results it shows that the saxion is stable in our universe and can play the role of the late decaying particle (LDP) in a dark matter.

hep-ph

Trilinear gauge boson couplings and bilepton production in the SU(3)_C X SU(3)_L X U(1)_N models

The trilinear gauge boson couplings in the SU(3)_C X SU(3)_L X U(1)_N (3 - 3 - 1) models are presented. We find that new $Z_2$ does not interact with the usual (in the standard model) gauge bosons $Z, W^\pm$. Based on these results, production of new heavy gauge bosons at high energy colliders such as e^+ e^- is calculated. We show that the cross sections obtained in the 3 - 3 - 1 model with right-handed neutrinos can be one order bigger than the same in the minimal 3 - 3 - 1 model.

hep-ph

Bounds on masses of new gauge bosons in the 3 - 3 -1 models

Contribution from new gauge bosons in the 3 - 3 - 1 models to the anomalous magnetic moment of the muon, mass difference of the kaon system and rare kaon decay are calculated and numerically estimated. Bounds on masses of new gauge bosons: bileptons and Z' are derived.

hep-ph

Anomalous magnetic moment of muon in 3-3-1 models

A contribution from new gauge bosons in the ${SU}(3)_C\otimes {SU}(3)_L \otimes {U}(1)_N$ (3 - 3 - 1) models to the anomalous magnetic moments of the muon is calculated and numerically estimated. In the minimal 3 - 3 - 1 model, a lower bound on the bilepton mass at a value of 167 GeV is derived. For an expected precision($\sim 4\times 10^{-10}$) of the BNL measurements the possible lower bounds on masses of the bileptons in the minimal version and in the version with right-handed neutrinos are around 940 GeV and 250 GeV, respectively.

hep-ph

Electromagnetic detection of axions

Photon-to-axion conversions in the static electromagnetic fields are reconsidered in detail by using the Feynman diagram techniques. The differential cross sections are presented for the conversions in the presence of the electric field of the flat condenser as well as in the magnetic field of the solenoid. Based on our results a laboratory experiment for the production and the detection of the axions is described. This experiment will exploit the axion decay constant as well as the axion mass.

hep-ph

Electromgnetic-gravitational cross-sections in external elctromagnetic fields

The classical processes: the conversion of photons into gravitons in the static electromagnetic fields are considered by using Feynman perturbation techniques. The differential cross sections are presented for the conversion in the electric field of the flat condesor and the magnetic field of the selenoid. A numerical evaluation shows that the cross sections may have the observable value in the present technical scenario.

astro-ph