Theoretical analysis of direct $CP$ violation and differential decay width in $D^\pm\to π^\pm π^+π^-$ in phase space around the resonances $ρ^0(770)$ and $f_0(500)$
Zhen-Hua Zhang, Ren Song, Yu-Mo Su, Gang Lü, Bo Zheng
We perform a theoretical study on direct $CP$ violation in $D^\pm\to π^\pm π^+π^-$ in phase space around the intermediate states $ρ^0(770)$ and $f_0(500)$. The possible interference between the amplitudes corresponding to the two resonances is taken into account, and the relative strong phase of the two amplitudes is treated as a free parameter. Our analysis shows that by properly chosen the strong phase, both the $CP$ violation strength and differential decay width accommodate to the experimental results.
Both BaBar and Belle have found evidence for a non-zero width difference in the $D^0$-$\bar D^0$ system. Although there is no direct experimental evidence for CP-violation in $D$ mixing (yet), we show that the measured values of the width difference $y\sim ΔΓ$ already imply constraints on the CP-violating phase in $D$ mixing, which, if significantly different from zero, would be an unambiguous signal of new physics.
In Perturbative QCD (PQCD) approach we study the direct $CP$ violation in the pure annihilation decay process of $\bar{B}^0_{s}\rightarrowπ^+π^-π^+π^-$ induced by the $ρ$ and $ω$ double resonance effect. Generally, the $CP$ violation is small in the pure annihilation type decay process. However, we find that the $CP$ violation can be enhanced by double $ρ-ω$ interference when the invariant masses of the $π^+π^-$ pairs are in the vicinity of the $ω$ resonance. For the decay process of $\bar{B}^0_{s}\rightarrowπ^+π^-π^+π^-$, the maximum $CP$ violation can reach 28.64{\%}.
We calculate the width difference of the scalar electron decay, $Γ(\tilde e_L \to e_Lω) - Γ({\bar{\tilde e}}_L \to \bar e_Lω)$ in the softly broken supersymmetrized standard model. The CP asymmetry is assumed to arise from the complex gaugino masses. Even in limit that the electron mass $m_e$ is vanishing, the difference can be of the order of $α$.
We investigate a possibility of observing CP asymmetries in the partial widths for the decays B^- -> pi^+ pi^- K^- and B^- -> K^+ K^- K^- produced by the interference of the non-resonant decay amplitude with the resonant amplitudes. The resonant states which subsequently decay into pi^+ pi^- and K^+ K^- or K^- pi^+ are charmonium c(bar) c states with J^P = 0^+, 1^-, 1^+ or the phi(1020) meson. We find that the largest partial width asymmetry comes from the chi_c0 resonance, while the resonances K^*_0(1430) and psi(2S) give a partial width asymmetry of the order 10%.
We discuss the effect of CP-violating $Zb\bar{b}$, $Zb\bar{b}G$ and $Zb\bar{b}γ$ couplings on the width $Γ(Z\rightarrow b\bar bX)$. The presence of such couplings leads in a natural way to an increase of this width relative to the prediction of the standard model. Various strategies of a direct search for such CP-violating couplings by using CP-odd observables are outlined. The number of $Z$ bosons required to obtain significant information on the couplings in this way is well within the reach of present LEP experiments.
In supersymmetric models with R-parity violating interactions, sneutrinos may be produced as $s$-channel resonances at $μ^+ μ^-$ colliders. We demonstrate that, for R-parity violating couplings as low as $10^{-4}$, sneutrinos can be discovered and their couplings measured to high accuracy. The excellent beam energy resolution of muon colliders is found to be especially useful for studying such resonances in certain cases.
In supersymmetric models with R-parity violation, sneutrinos may be produced as s-channel resonances at muon colliders. We demonstrate that, for R-parity violating couplings as low as 10^-4, sneutrino resonances may be observed and may be exploited to yield high precision SUSY parameter measurements. The excellent beam energy resolution of muon colliders may also be used to resolve MeV level splittings between CP-even and CP-odd sneutrino mass eigenstates.
We suggest using the half-width rule to make an estimate of the 1/Nc errors in hadronic models containing resonances. We show simple consequences ranging from the analysis of meson Regge trajectories, the hadron resonance gas at finite temperature and generalized hadronic form factors.
The physical state of $ρ$-$ω$-$ϕ$ mesons can be mixed by the unitary matrix. The decay processes of $ω\rightarrow π^{+}π^{-}$ and $ϕ\rightarrow π^{+}π^{-}$ are from the isospin symmetry breaking. The $ρ-ω$, $ρ-ϕ$ and $ω-ϕ$ interferences lead to resonance contribution to produce the strong phases. The $CP$ asymmetry is considered from above isospin symmetry breaking due to the new strong phase for the first order. It has been found the $CP$ asymmetry can be enhanced greatly for the decay process of $B^{0}\rightarrowπ^+π^{-}η^{(')}$ when the invariant masses of the $π^+π^{-}$ pairs are in the ar…
The pole mass and the width of the Roper resonance are calculated as functions of the pion mass in the framework of low-energy effective field theory of the strong interactions. We implement a systematic power-counting procedure by applying the complex-mass renormalization scheme.
We study the decay width and CP asymmetry of the inclusive process b--> s g (g denotes gluon) in the multi Higgs doublet models with complex Yukawa couplings, including next to leading QCD corrections. We analyse the dependencies of the decay width and CP asymmetry on the scale μand CP violating parameter θ. We observe that there exist an enhancement in the decay width and CP asymmetry is at the order of 10^{-2}.
We calculate the width of the delta resonance at leading two-loop order in baryon chiral perturbation theory. This gives a correlation between the leading pion-nucleon-delta and pion-delta couplings, which is relevant for the analysis of pion-nucleon scattering and other processes.
Pion-pion scattering amplitude obtained from one-loop Chiral Perturbation Theory (ChPT) is crossing symmetric, however the corresponding partial wave amplitudes do not respect exact unitarity relation. There are different approaches to get unitarized partial wave amplitudes from ChPT. Here we consider the inverse amplitude method (IAM) that is often used to fit pion-pion phase shifts to experimental data, by adjusting free parameters. We measure the amount of crossing symmetry violation (CSV) in this case and we show that crossing symmetry is badly violated by the IAM unitarized ChPT amplitude…
We calculate the width of the Roper resonance at next-to-leading order in a systematic expansion of baryon chiral perturbation theory with pions, nucleons, and the delta and Roper resonances as dynamical degrees of freedom. Three unknown low-energy constants contribute up to the given order. One of them can be fixed by reproducing the empirical value for the width of the Roper decay into a pion and a nucleon. Assuming that the remaining two couplings of the Roper interaction take values equal to those of the nucleon, the result for the width of the Roper decaying into a nucleon and two pions i…
Hadron resonances affect nonexotic $D^o$ decays but not $B$ decays which are far from the resonance region. We obtain new information from {\bf exclusive} decays and show that interference between colour favoured and colour suppressed diagrams is {\bf constructive} in $B$ and (some) $D$ decays in contrast to the inclusive decays where a net Pauli destructive interference is claimed. We suggest that a systematic study of $B$ decay final states containing excited mesons such as $a_1 D$ or $πD^{**}$ show opposite behaviour for $B^o$ and $B^+$ relative to the ground state channels. We give inequal…
We consider new s-channel scalar exchanges in top quark and massive gauge-bosons pair production in e+e- collisions, in supersymmetry with a small lepton number violation. We show that a soft bilinear lepton number violating term in the scalar potential which mixes the Higgs and the slepton fields can give rise to a significant scalar resonance enhancement in e+e- -> ZZ, W+W- and in e+e- -> t t(bar). The sneutrino-Higgs mixed state couples to the incoming light leptons through its sneutrino component and to either the top quark or the massive gauge bosons through its Higgs component. Such a sc…
Within the resonance chiral effective theory we study the dressed propagators of the spin-1 fields, as arise from a Dyson-Schwinger resummation perturbatively constructed from loop diagrams with absorptive contributions in the s-channel. We apply the procedure to the vector pion form factor and the elastic pion-pion scattering to obtain the off-shell width of the rho_0 meson. We adopt a definition of the off-shell width of spin-1 meson resonances that satisfies the requirements of analyticity, unitarity, chiral symmetry and asymptotic behaviour ruled by QCD. To fulfil these constraints the res…
A general theory of pseudomagnetic effects for the propagation of polarized neutrons through polarized target in multi resonance approach is presented. Some applications related to the proposed search for time reversal invariance violation in neutron scattering are considered.
We consider CP violating effects in decays of the type $B\rightarrow k_iγ\rightarrow Kπγ$, $K^*πγ$ and $Kργ$, where $k_i$ represents a strange meson resonance. We include in our calculations five of the low-lying resonances with quantum numbers ($J^P$) $1^-$, $1^+$ and $2^+$. At the quark level these decays are driven by the penguin graph as well as tree graphs. CP violation arises due to the difference in the CKM phase between these graphs. We model the final state interaction of the hadronic system using the low lying $k_i$ resonances. We find that radiative decays of B mesons give rise to f…
We compute the width of the decay $h^0$ (125 GeV) $\to b \bar{b}$ at next-to-leading order in the general MSSM with quark-flavour violation (QFV). We study the effect of mixing between the second and the third generation of squarks, taking into account the constraints on QFV from B-meson data. We discuss the renormalisation of the process as well as the resummation of the bottom Yukawa coupling at large $\tan β$. We show numerical results on the decay width $Γ(h^0 \to b \bar{b})$ as a function of the involved QFV parameters and compare them with the corresponding width in the Standard Model.
New physics field content in the nature, more specifically, from spin-1 resonances sourced by the extension of the SM local gauge symmetry to the larger local group $SU(2)_L\otimes SU(2)_R\otimes U(1)_{B-L}$, may induce CP-violation signalling NP effects from higher energy regimes. In this work we completely list and study all the CP-violating operators up to the $p^4$-order in the Lagrangian expansion, for a non-linear left-right electroweak chiral context and coupled to a light dynamical Higgs. Heavy right handed fields can be integrated out from the physical spectrum, inducing thus a physic…
We consider the first pion excitation as a sub-continuum resonance in the pseudoscalar channel, and we obtain parameters characterizing this resonance through a global fit of the Borel-parameter dependence of the field-theoretical pseudoscalar Laplace sum rule to its hadronic (pion + pion-excitation + QCD-continuum) content. Our analysis incorporates finite-width deviations from the narrow resonance approximation, instanton effects, and higher-loop perturbative contributions to the pseudoscalar correlator. We obtain the following values (uncertainties reflect 90% confidence levels): mass $M_Π=…
Electromagnetic resonant cavities form the basis of many tests of Lorentz invariance involving photons. The effects of some forms of Lorentz violation scale with cavity size. We investigate possible signals of violations in the naturally occurring resonances formed in the Earth-ionosphere cavity. Comparison with observed resonances places the first terrestrial constraints on coefficients associated with dimension-three Lorentz-violating operators at the level of 10^{-20} GeV.
We present an elementary derivation of the width of photon decay in a weak magnetic field using the semiclassical method of worldline instantons. The calculation is generalized to a model of quantum electrodynamics with broken Lorentz symmetry. Implications for the search of deviations from Lorentz invariance in the cosmic ray experiments are discussed.
We demonstrate that near the threshold, the pi pi scattering amplitude contains a pole with the quantum numbers of the vacuum - commonly referred to as the sigma - and determine its mass and width within small uncertainties. Our derivation does not involve models or parametrizations, but relies on a straightforward calculation based on the Roy equation for the isoscalar S-wave.
We study the two-body decays of the gluino at full one-loop level in the Minimal Supersymmetric Standard Model with quark-flavour violation (QFV) in the squark sector. The renormalization is done in the DRbar scheme and hard gluon and photon radiations are included by adding the corresponding three-body decay widths. In the numerics the dependence of the gluino decay widths on the QFV parameters is discussed with special emphasis put on the separation of the electroweak and the SUSY QCD corrections. The main dependence stems from the $\tilde c_R - \tilde t_R$ mixing in the decays to up-type sq…
Whether one starts form the analytic S-matrix definition or the requirement of gauge parameter independence in renormalization theory, a relativistic resonance is given by a pole at a complex value s of energy squared. The complex number s does not define the mass and width separately and this definition does not lead to interfering Breit-Wigner if two or more resonances are involved. To accomplish both we invoke the decaying particle aspect of a resonance and associate to each pole a space of relativistic Gamow kets which transform irreducibly under causal Poincare transformations. A Gamow st…
Large CP violation is an interesting phenomenon both theoretically and experimentally. Last year, LHCb Collaboration found in some three-body decays of bottom mesons that large CP violations appear in regions of the Dalitz plots that are not dominated by contributions from narrow resonances. In this paper, we present a mechanism which can induce such kind of large CP violations. In this mechanism, large localized CP asymmetries in phase space can be induced by the interference of two intermediate resonances with different spins. We also apply this mechanism to the decay channel $B^\pm\to K^\pm…
I. Caprini's, G. Colangelo's, and H. Leutwyler's (CCL) article "Mass and Width of the Lowest Resonance in QCD", Phys. Rev. Lett. 96, 132001 (2006) [hep-ph/0512364], is critically reviewed. The present comment is devoted to complement a recent experimental discussion (D.V. Bugg, J. Phys. G 34, 151 (2007) [hep-ph/0608081]) of short-comings in the CCL analysis, by presenting theoretical arguments pointing at a serious flaw in the theoretical formalism used by CCL, and also at the unlikeliness of their tiny error bars in the sigma-meson mass and width. The criticism made in the comment applies ana…
B-B-bar mixing involves three physical parameters: the magnitudes of the off-diagonal elements of the mass and decay matrices and their relative phase. They are related to the mass and width differences between the mass eigenstates and to the CP asymmetry in flavour-specific decays, a_fs. Introducing a new operator basis I present new, more precise theory predictions for the width differences in the B_s and B_d systems: in the Standard Model one finds Delta Gamma_s = 0.088 +/- 0.017 ps^{-1} and Delta Gamma_d = (26.7 +5.8/-6.5) * 10^{-4} ps^{-1}. Updates of the mass differences Delta M_d and De…
We compute the decay width of $h^0 \to c \bar{c}$ in the MSSM with quark flavor violation (QFV) at full one-loop level adopting the $\overline{\rm DR}$ renormalisation scheme. We study the effects of $\tilde{c}-\tilde{t}$ mixing, taking into account the constraints from the B meson data. We show that the full one-loop corrected decay width $Γ(h^0 \to c \bar{c})$ is very sensitive to the MSSM QFV parameters. In a scenario with large $\tilde{c}_{L,R}-\tilde{t}_{L,R}$ mixing $Γ(h^0 \to c \bar{c})$ can differ up to $\sim \pm 35\%$ from its SM value. After estimating the uncertainties of the width,…
We exploit offshell regions in the process $e^+e^-\rightarrow W^+W^-b\bar{b}$ to gain access to the top-quark width. Working at next-to-leading order in QCD we show that carefully selected ratios of offshell regions to onshell regions in the reconstructed top and antitop invariant mass spectra are, \emph{independently} of the coupling $g_{tbW}$, sensitive to the top-quark width. We explore this approach for different centre of mass energies and initial-state beam polarisations at $e^+e^-$ colliders and briefly comment on the applicability of this method for a measurement of the top-quark width…
We calculate low-energy meson decay processes and pion-pion scattering lengths in a two-flavour linear sigma model with global chiral symmetry, exploring the scenario in which the scalar mesons $f_0$(600) and $a_0$(980) are assumed to be $\bar q q$ states.
Leptonic CP violation is one of the most important topics in neutrino physics. CP violation in the neutrino sector is strongly related to the nature of neutrinos: whether they are Dirac or Majorana particles. In \cite{Popov:2021icg} we have shown that for Majorana neutrinos arance of nonzero Majorana CP-violating phases combined with strong magnetic field during supernova core-collaple can induce new resonances in neutrino oscillations, for example in $ν_e \to \barν_τ$ channel. In this contribution we further study new resonances in Majorana neutrino oscillations, in particular energy dependen…
In the article of V.V. Anisovich et al., Yad. Fiz. 63, 1489 (2000), the K-matrix solutions for the wave IJ^{PC}=00^{++} were obtained in the mass region 450 - 1900 MeV where four resonances f0(980), f0(1300), f0(1500), f0(1750) and the broad state f0(1530^{+90}_{-250}) are located. Based on these solutions, we determine partial widths for scalar-isoscalar states decaying into the channels pi-pi, K-anti K, eta-eta, eta-eta', pi-pi-pi-pi and corresponding decay couplings.
We study the role of finite widths of resonances in a nonlocal version of the Wick-Cutkosky model. The spectrum of bound states is known analytically in this model and forms linear Regge tragectories. We compute the widths of resonances, calculate the spectral density in an extension of the Breit-Wigner {\it ansatz} and discuss a mechanism for the damping of unphysical exponential growth of observables at high energy due to finite widths of resonances.
Resonance width effects in charged $B$ decays to neutral $D$ mesons and excited kaon states $K_i$ around 1400 MeV are shown to lead to large calculable final state phases. $CP$ asymmetries are defined for any charged $B$ decay to three pseudoscalar mesons involving intermediate overlapping resonance states. Asymmetries up to about 10$\%$ are found in $B^+\to K^+_i D^0\to (Kπ)^+ D^0$. Decay distributions can be used to determine the weak phase $γ$ of the Cabibbo-Kobayashi-Maskawa (CKM) matrix. No separation of the contributions from individual resonances is required.
A QCD Laplace sum rule framework is employed to investigate the relationship between the mass and the decay width of the sigma, the lowest-lying isoscalar resonance in the spin-zero meson channel. Our analysis differs from prior analyses, not only by incorporating finite-width departures from the narrow resonance approximation, but also through the inclusion of direct-instanton contributions and three-loop-order perturbative effects. Assuming that the sigma is the dominant subcontinuum resonance in this channel, the least upper bound we obtain for the sigma-mass is shown to increase with the s…
The low energy behaviour of Quantum Chromodynamics makes unreliable an expansion in terms of its coupling strength, since nothing guarantees the convergence of such expansion. To overcomer such difficulty one resorts to Lattice QCD or Effective Field Theories. In this thesis we compute hadronic processes at low energies, using Resonance Chiral Lagrangians as the effective theory of QCD. The processes we study are important background on the search for Lepton Flavor Violation, Lepton Universality Violation, Lepton Number Violation, Second Class Currents and study the Hadronic light-by-light con…
Quantitative understanding of CP violation is extremely important as naturalness reasoning strongly suggests that new physics should be accompanied by beyond the Standard Model CP-odd phases. In 2019 LHCb made the first $5 σ$ discovery of CP violation in the charm system, leading to the new world average $Δa_{CP}^{\mathrm{dir}} = -0.00161 \pm 0.00028$. While some calculations have found this observation as requiring new physics, we suggest that scalar resonances nearby to $m_{D^0}$, in particular, $f_0(1710)$ and/or $f_0(1790)$ cause enhancements for CP violation within the SM. Thereby, our ca…
The experimental data on pi N scattering in the elastic energy region T_pi < 250 MeV are analyzed within the multichannel K-matrix approach with effective Lagrangians. Isospin invariance is not assumed in this analysis and the physical values for masses of the involved particles are used. The corrections due to pi^+- pi^0 and p-n mass differences are calculated and found to be in a reasonable agreement with the NORDITA results. Analysis shows the good description of the all experimental observables. From the data, new values for mass and width of the Delta^0 and Delta^{++} resonances were obta…
Within the standard model we carry out an analysis of $CP$-violating observables in neutral $B$-meson decays at the $Υ(4S)$ resonance. Both time-dependent and time-integrated $CP$ asymmetries are calculated, without special approximations, to meet various possible measurements at symmetric and asymmetric $e^{+}e^{-}$ $B$ factories. We show two ways to distinguish between direct and indirect $CP$-violating effects in the $CP$-eigenstate channels such as $B^{0}_{d}/\bar{B}^{0}_{d}\rightarrow π^{+}π^{-}$ and $π^{0} K_{S}$. Reliable knowledge of the Cabibbo-Kobayashi-Maskawa phase and angles can i…
Using recent results obtained within the hidden gauge formalism for vector mesons, in which the $f_0(1370)$ and $f_2(1270)$ resonances are dynamically generated resonances from the $ρρ$ interaction, we evaluate the radiative decay of these resonances into $γγ$. We obtain results for the width in good agreement with the experimental data for the $f_2(1270)$ state and a width about a factor five smaller for the $f_0(1370)$ resonance, which would agree with preliminary results from the Belle collaboration, hinting at an order of magnitude smaller width for this resonance than for the $f_2(1270)$.
Motivated by the possibility of enhancing dark matter (DM) self-interaction cross-section $σ_{\rm self}$, we have revisited the issue of DM annihilation through a Breit-Wigner resonance. In this case thermally averaged annihilation cross-section has strong temperature dependence, whereas elastic scattering of DM on the thermal bath particles is suppressed. This leads to the early kinetic decoupling of DM and an interesting interplay in the evolution of DM density and temperature that can be described by a set of coupled Boltzmann equations. The standard Breit-Wigner parametrization of a resona…
We discuss direct CP violation in three-body decays of $B$ meson such as $B^\pm \to K^\pmπ^+π^-$, which involves various intermediate resonance states, such as $B^\pm \to K^*_i π^\pm$ and $B^\pm \to ρK^\pm$, where $K^*_i$ represents the $πK$ resonance. Due to the large final state interaction phases of the resonances, the CP asymmetry can be as large as the 25% level near the kinematical region where the $K^*_i$ and $ρ$ resonances overlap. By examining a Dalitz plot of this mode and combining a measurement of the branching ratio for $B^\pm \to ρ^\pm K$, it is possible to extract the weak phase…
We study the width of a two-body resonance in a coupled-channel system. We demonstrate how the width does not come only determined by the available phase space for its decay to the detection channel, but it greatly depends on the relative position of the mass of the resonance with respect to the masses of the coupled-channels generating the state. Our results are consistent with the experimental observation of narrow hadrons lying well above their lowest decay threshold.
We have examined the existence of the $N^*(1685)$ resonance, which is recently listed by the Particle Data Group as a one-star nucleon resonance, by using a covariant isobar model for kaon photoproduction and assuming that the resonance has $J^p=1/2^+$, in accordance with our previous finding. After the inclusion of this resonance the changes in the total $χ^2$ show two clear minima at $M_{N^*}=1650$ and 1696 MeV, which correspond to two different resonance states. The former corresponds to the narrow nucleon resonance found in our previous investigation, whereas the latter corresponds to a ne…
Yields of hadrons, their average masses and energies per hadron at the stage of chemical freeze-out in (ultra)relativistic heavy-ion collisions are analyzed within the statistical model. The violation of the scaling <E>/<N> = 1 GeV observed in Au+Au collisions at $\sqrt{s}$ = 130 AGeV is linked to the formation of resonance-rich matter with a considerable fraction of baryons and antibaryons. The rise of the energy-per-hadron ratio in baryon-dominated matter is discussed. A violation of the scaling condition is predicted for a very central zone of heavy-ion collisions at energies around 40 AGeV…
It has been recently reported an intriguing theoretical result of a narrow three-body resonance with a large available phase space. The resonance was reported in the $NΛΛ-ΞNN$ system near the $Ξd$ threshold, having a very small width in spite of the open $NΛΛ$ channel lying around 23 MeV below the $ΞNN$ channel. We use first-order perturbation theory as a plausible argument to explain this behavior. We apply our result to realistic local interactions. Other systems involving several thresholds are likely to follow the same behavior.
This study appertains to the extraction of estimates for the masses and for the partial decay widths to pion-nucleon final states of the well-established (four-star) $s$ and $p$ baryon resonances below $2$ GeV. These estimates are exclusively obtained from the data contained in the recent compilation by the Particle Data Group. Only the $N$ ($S=0,I=1/2$) and the $Δ$ ($S=0,I=3/2$) states are considered, where $S$ and $I$ denote strangeness and total isospin, respectively.
The search for heavy resonances in the dijet channel is part of the on-going physics programme, both at the Tevatron and at the LHC. Lower limits have been placed on the masses of dijet resonances predicted in a wide variety of models. However, across experiments, the search strategy assumes that the effect of the new particles is well-approximated by on-shell production and subsequent decay into a pair of jets. We examine the impact of off-shell effects on such searches, particularly for strongly interacting resonances.
The 750 GeV resonance observed by ATLAS and CMS may be explained by a gauge singlet scalar. This would provide an ideal candidate for a gauge singlet scalar alternative to Higgs Inflation, S-inflation. Here we discuss the relevant results of S-inflation in the context of the 750 GeV resonance. In particular, we show that a singlet scalar, if it is real, has a major advantage over the Higgs boson with regard to unitarity violation during inflation. This is because it is possible to restrict the large non-minimal coupling required for inflation, $ξ\sim 10^5$, to the real singlet scalar, with all…
We calculate the decay width of $h^0(125GeV) \to c \bar{c}$ in the Minimal Supersymmetric Standard Model (MSSM) with non-minimal quark flavor violation (QFV) at full one-loop level. We adopt the $\overline{\rm DR}$ renormalization scheme. We study the effects of the mixing of the second and third squark generations (i.e. scharm-stop mixing) on the decay width, respecting the experimental constraints from B-meson data, the Higgs mass measurement and supersymmetric (SUSY) particle searches. We show that the decay width $Γ(h^0 \to c \bar{c})$ at the full one-loop level is very sensitive to the SU…
The mass spectra of strange baryons in the octet family are investigated in a finite-energy QCD sum rule approach based on the Gauss-Weierstrass transform. The phenomenological form of the spectral function is saturated by the ground state and two of the lowest excited states, considered as having opposite parities. Treating the ground state parameters as known, the masses, widths and couplings to the interpolating fields are determined and compared to experiment.
In this paper the interfering resonances parameters determination ambiguity is considered. It is shown that there are two solutions for two fixed width resonances. Analytical relation between different solutions is derived. Numeric experiments for fixed width three and four resonances, and for model energy-dependent width two resonances confirm ambiguity of the resonances parameters determination.
