Quark diagram analysis of <Emphasis Type="Italic">B</Emphasis>-meson emitting vector (<Emphasis Type="Italic">V</Emphasis>) and vector (<Emphasis Type="Italic">V</Emphasis>) mesons

This paper presents the two body weak nonleptonic decays of B-mesons emitting vector (V) and vector (V) mesons within the framework of the diagrammatic approaches at flavor SU(3) symmetry. We have investigated exclusive two body decays of B-meson using model independent quark diagram scheme. We have shown that the recent measurement of the two body exclusive decays of B-mesons can allow us to determine the magnitude and even sign of the QD amplitude for B → VV decays. Therefore, we become able to make few predictions for their branching fractions.     

<Emphasis Type="Italic">B</Emphasis>-meson decays into charmonium states in the ATLAS experiment

The paper presents several recent ATLAS results on the analyses of B-meson decays into charmonium states. These include the measurements of B⁺ mass and the fractions of J/ψ mesons produced in b-hadron decays in pp collisions at \(\sqrt s\) = 13 TeV in the center of mass system. The measured partial widths and polarizations in B _c ⁺ → J/ψD _s ^(*)+ decays and CP-violation parameters in B _s ⁰ → J/ψ? decays in pp collisions at 7 and 8 TeV in the center of mass system are also presented.     

Effect of FCNC mediated <Emphasis Type="Italic">Z</Emphasis> boson on lepton flavor violating decays

We study the three body lepton flavor violating (LFV) decays μ ^?→e ^? e ⁺ e ^?, \(\tau^{-} \to l_{i}^{-} l_{j}^{+} l_{j}^{-}\) and the semileptonic decay τ→μφ in the flavor changing neutral current (FCNC) mediated Z boson model. We also calculate the branching ratios for LFV leptonic B decays, B _d,s →μe, B _d,s →τe, B _d,s →τμ and the conversion of muon to electron in Ti nucleus. The new physics parameter space is constrained by using the experimental limits on μ ^?→e ^? e ⁺ e ^? and τ ^?→μ ^? μ ⁺ μ ^?. We find that the branching ratios for τ→eee and τ→μφ processes could be as large as \({\sim}{\mathcal{O}}(10^{-8})\) and \(\mathrm{Br}(B_{d,s} \to \tau \mu,~ \tau e) \sim {\mathcal{O}}(10^{-10})\). For other LFV B decays the branching ratios are found to be too small to be observed in the near future.     

The electromagnetic effects in <Emphasis Type="Italic">K</Emphasis><Subscript><Emphasis Type="Italic">e</Emphasis>4</Subscript> decay

The final-state interaction of pions in K _e4 decay allows to obtain the value of the isospin and angular-momentum-zero ππ scattering length a ₀ ⁰ .We take into account the electromagnetic interaction of pions and isospin-symmetry-breaking effects caused by different masses of neutral and charged pions and estimate the impact of these effects on the procedure of scattering-length extraction from K _e4 decays.     

1/<Emphasis Type="Italic">N</Emphasis><Subscript><Emphasis Type="Italic">c</Emphasis></Subscript> countings in baryons

The 1/N _c -power countings for baryon decays and configuration mixings are determined by means of a nonrelativistic quark picture. Such countings are expected to be robust under changes in the quark masses and, therefore, valid as these become light. It is shown that excited baryons have natural widths of \(\mathcal{O}(N_c^0 )\). These dominant widths are due to the decays that proceed directly to the ground-state baryons, with cascade decays being suppressed to \(\mathcal{O}(1/N_c )\). Configuration mixings, defined as mixings between states belonging to different O(3) × SU(2N _f ) multiplets, are shown to be subleading in an expansion in \(1/\sqrt {N_c }\) when they involve the ground-state baryons, while the mixings between excited states can be \(\mathcal{O}(N_c^0 )\).     

Decay Behaviors of the <Emphasis Type="Italic">P</Emphasis><Subscript><Emphasis Type="Italic">c</Emphasis></Subscript> Hadronic Molecules

In this proceeding, we present our recent work on decay behaviors of the P_c hadronic molecules, which can help to disentangle the nature of the two P_c pentaquark-like structures. The results turn out that the relative ratio of the decays of P _c ⁺ (4380) to \({\bar D *}{\Lambda _c}\) and J/ψp is very different for P_c being a \({\bar D *}{\Sigma _c}\) or \(\bar D\Sigma _c *\) bound state with \({J^P} = \frac{{{3 - }}}{2}\) And from the total decay width, we find that P_c(4380) being a \(\bar D\Sigma _c *\) molecule state with \({J^P} = \frac{{{3 - }}}{2}\) and P_c(4450) being a \({\bar D *}{\Sigma _c}\) molecule state with \({J^P} = \frac{{{5 + }}}{2}\) is more favorable to the experimental data.     

Four-Leptonic Decays of Charged and Neutral <Emphasis Type="Italic">B</Emphasis> Mesons within the Standard Model

The branching ratios and differential distributions for the four-leptonic decays \({B^ - } \to {\mu ^ + }{\mu ^ - }{\bar v_e}{e^ - }\), \({B^ - } \to {e^ + }{e^ - }{\bar v_\mu }{\mu ^ - }\), and \({B^ - } \to {\mu ^ + }{\bar v_\mu }{\mu ^ - }{\mu ^ - }\) are calculated within the Standard Model. The branching ratios for the rare decays B_d,s → e⁺e^?μ⁺μ^? and B_d,s → μ⁺μ^?μ⁺μ^? are estimated. Methods for testing the lepton universality in rare multileptonic decays of charged and neutral B mesons are proposed.     

<Emphasis Type="Italic">B</Emphasis><Subscript><Emphasis Type="Italic">c</Emphasis></Subscript> meson rare decays in the light-cone quark model

We investigate the rare decays \(B_{c} \rightarrow D_{s}(1968)\ell \overline{\ell}\) and \(B_{c}\rightarrow D_{s}^{*}(2317) \ell \overline{\ell}\) in the framework of the light-cone quark model (LCQM). The transition form factors are calculated in the space-like region and then analytically continued to the time-like region via exponential parametrization. The branching ratios and longitudinal lepton polarization asymmetries (LPAs) for the two decays are given and compared with each other. The results are helpful for investigating the structure of B _c meson and for testing the unitarity of CKM quark mixing matrix. All these results can be tested in the future experiments at the LHC.     

Mixing of <Emphasis Type="Italic">K</Emphasis><Superscript>0</Superscript> and <Emphasis Type="Italic">B</Emphasis><Superscript>0</Superscript> neutral mesons within the minimum supersymmetry model

Mixing of K ⁰ and B ⁰ mesons is studied in the scope of the minimum supersymmetry model (MSSM) with a type II Yukawa sector and explicit violation of CP invariance in the Higgs potential. The mixing parameters Δm _LS and ? are calculated in the limit of the low-energy four-fermion approximation with a charged Higgs boson exchange. It is shown that supersymmetric effects are very small for K ⁰ mesons and may be quite significant for B _s ⁰ and B _d ⁰ mesons, which imposes constraints on the MSSM parameter space.     

Ferromagnetism and ferroelectricity in Eu<Emphasis Type="Italic">X</Emphasis> (<Emphasis Type="Italic">X</Emphasis> = <Emphasis Type="Italic">O</Emphasis>, <Emphasis Type="Italic">S</Emphasis>): pressure effects

Ferromagnetism and ferroelectricity in Eu monochalcogenides have been investigated by ab initio density functional theory in the DFT+U approach. Exchange interaction parameters and Curie temperatures under pressure are studied and discussed using Heisenberg Hamiltonian with first and second-nearest-neighbor interactions. The calculations showed that the hydrostatic pressure perfectly improves the Curie temperature (EuO: T _C = 175 K; EuS: T _C = 33.8 K) and in the other hand it cannot induce the spontaneous polarization (P _s ). The effect of uniaxial and biaxial pressure is also studied. Although the uniaxial strains slightly increases the Curie temperature, it ensures the ferrolectricity in these systems by producing a spontaneous polarization of the order of P _s (EuO) = 57.50 μC/cm² and P _s (EuS) = 42.86 μC/cm² with pressures of 5% and 4%, respectively. The search for new model systems is a necessity to better understand the physics related to multiferroïc materials and to consider possible applications.     

Extended <Emphasis Type="Italic">E</Emphasis>(5) and <Emphasis Type="Italic">X</Emphasis>(5) symmetries: Series of models providing parameter-independent predictions

The E(5) symmetry describes nuclei related to the U(5)-SO(6) phase transition, while the X(5) symmetry is related to the U(5)-SU(3) phase transition. First, a chain of potentials interpolating between the U(5) symmetry of the five-dimensional harmonic oscillator and the E(5) symmetry is considered. Parameter-independent predictions for the spectra and B(E2) values of nuclei with R₄ = E(4)/E(2) ratios of 2.093, 2.135, and 2.157 (compared to the ratio of 2.000 of the U(5) case and the ratio of 2.199 of the E(5) case) are derived numerically and compared to existing experimental data, suggesting several new experiments. TheX(5) symmetry describes nuclei characterized byR₄=2.904.Using the same separation of variables of the original Bohr Hamiltonian as in X(5), an exactly soluble model with R₄=2.646 is constructed and its parameter-independent predictions are compared to existing spectra and B(E2) values. In addition, a chain of potentials interpolating between this new model and the X(5) symmetry is considered. Parameter-independent predictions for the spectra and B(E2) values of nuclei with R₄ ratios of 2.769, 2.824, and 2.852 are derived numerically and compared to existing experimental data, suggesting several new experiments.     

<Emphasis Type="Italic">K</Emphasis><Subscript><Emphasis Type="Italic">e</Emphasis>3</Subscript> Decay Studies in the OKA Experiment

Recent results from OKA setup concerning form factor studies in K_e3 decay are presented. About 5.25 M events obtained for decays of 17.7 GeV/cK⁺ are selected for the analysis. The linear and quadratic slopes for the decay form factor f₊(t) are measured: λ'₊ = 2.95 ± 0.022 ± 0.018 × 10 ^-2 for the linear slope fit and λ₊ = 2.611 ± 0.035 ± 0.028 × 10 ^-2, λ"₊ = 1.91 ± 0.19 ± 0.14 × 10 ^-3 for the quadratic one. The scalar and tensor contributions are compatible with zero. Several alternative parametrizations are tried: the Pole fit parameter is found to be M _V = 891 ± 3 MeV; the parameter of the dispersive parametrization is measured to be Λ₊ = 2.458 ± 0.018 × 10^-2.     

Surface superconductivity and<Emphasis Type="Italic">H</Emphasis><Subscript><Emphasis Type="Italic">c3</Emphasis></Subscript> in UPt<Subscript>3</Subscript>

Ginzburg-Landau (GL) theory is used to study surface superconductivity for UPt₃ for various order parameter symmetries (OPS), andH _c3 is found for all principal directions of the surface normal\(\hat n\) and the field [1]. Assuming specular reflection, and allowing for reorientation of the antiferromagnetic symmetry breaking field in the models withE _1g ,E _2g ,E _1u , orE _2u symmetry, the experiments of Keller et al. [2] with\(\hat n = \hat a\) can be qualitatively explained for all OPS except possiblyA _1u ⊕B _1u . The implied GL parameters then predict qualitatively different and OPS dependent behavior for\(\hat n = \hat a^* \) and\(\hat n = \hat c\). Study ofH _c3 for these surfaces would give strong clues about the OPS of UPt₃.     

Top-quark <Emphasis Type="Italic">p</Emphasis><Subscript><Emphasis Type="Italic">T</Emphasis></Subscript>-spectra at CMS and flavor independence of <Emphasis Type="Italic">z</Emphasis>-scaling

We present new results of analysis of top-quark differential cross sections obtained by the CMS Collaboration in pp collisions in the framework of the z-scaling approach. The spectra are measured over a wide range of collision energy \(\sqrt s = 7,8,13TeV\) and transverse momentum p _T = 30?500 GeV/c of top-quark using leptonic and jet decay modes. Flavor independence of the scaling function ψ(z) is verified in the new kinematic range. The results of analysis of the top-quark spectra obtained at the LHC are compared with similar spectra measured in \(\overline p p\) collisions at the Tevatron energy \(\sqrt s = 1.96TeV\). A tendency to saturation of ψ(z) for the process at low z and a power-law behavior of ψ(z) at high z is observed. The measurements of high-p _T is observed. The measurements of highspectra of the top-quark production at highest LHC energy is of interest for verification of self-similarity of particle production, understanding flavor origin and search for new physics symmetries with top-quark probe.     

Spherical Symmetric Perfect Fluid Collapse in <Emphasis Type="Italic">f</Emphasis>(<Emphasis Type="Italic">R</Emphasis>, <Emphasis Type="Italic">T</Emphasis>) Gravity

This paper contains the study of spherically symmetric perfect fluid collapse in the frame work of f(R, T) modified theory of gravity. We proceed our work by considering the non-static spherically symmetric background in the interior and static spherically symmetric background in the exterior regions of the star. The junction conditions between exterior and interior regions are presented by matching the exterior and interior regions. The field equations are solved by taking the assumptions that the Ricci scalar as well as the trace of energy-momentum tensor are to be constant, for a particular f(R, T) model. By inserting the solution of the field equations in junction conditions, we evaluate the gravitational mass of the collapsing system. Also, we discuss the apparent horizons and their time formation for different possible cases. It is concluded that the term f(R ₀, T ₀) behaves as a source of repulsive force and that’s why it slowdowns the collapse of the matter.     

New measurements on physics of <Emphasis Type="Italic">B</Emphasis>-hadrons in ATLAS experiment

Recent results on B-hadron physics in ATLAS are reviewed. A new measurement of CP-violating parameters in B _s → J/ψφ decay is performed on full Run 1 statistics. Branching fraction BR(B _s → μ⁺μ^?) = (0.9 _?0.8 ^+1.1 )×10^?9 is measured, below the Standard Model (SM) prediction.     

Mechanism of charge transfer in <Emphasis Type="Italic">n</Emphasis>-CdS/<Emphasis Type="Italic">p</Emphasis>-CdTe heterojunctions

The capacitance-voltage and current-voltage characteristics of the n-CdS/p-CdTe heterosystem are investigated. Analysis of these characteristics demonstrates that the CdTe_1?x S _x solid solution formed at the n-CdS/p-CdTe heterointerface is inhomogeneous in both the conductivity and composition. The thickness of solid solutions is estimated from the capacitance-voltage characteristics. It is shown that, for the n-CdS/p-CdTe heterosystem, the current-voltage characteristic in the current density range 10^?8-10^?5 A cm^?2 is governed by the thermal electron emission, whereas the current in the heterostructure at current densities in the range 10^?4-10^?2 A cm^?2 is limited by recombination of charge carriers in the electroneutral region of the CdTe_1?x S _x solid solution. The lifetime and the diffusion length of minority charge carriers in the CdTe_1?x S _x solid solution and the surface recombination rate at the interface between the CdS layer and the CdTe_1?x S _x solid solution are determined. It is demonstrated that the n-CdS/p-CdTe heterostructure operates as a p-i-n structure in which CdTe is a p layer, CdTe_1?x S _x is an i layer, and CdS is an n layer.     

Inclusive deuteron production in <Superscript>16</Superscript>O<Emphasis Type="Italic">p</Emphasis> collisions at a momentum of 3.25 GeV/<Emphasis Type="Italic">c</Emphasis> per nucleon

Experimental data on inclusive deuteron production in ¹⁶Op collisions at high energies were obtained for the first time under conditions of 4π geometry. An irregularity in the momentum spectrum of deuterons in the rest frame of oxygen nuclei is found in the range 0.40 ≤ p ≤ 0.55 GeV/c, and the reasons for its appearance are discussed. The mean multiplicities of secondary fragments are correlated with the presence of deuterons in an event, these correlations being positive for fragments of charge in the range z _f ≤ 4 and negative for fragments of charge in the range 5 ≤ z _f ≤ 7. This is likely to be due to baryon-charge conservation.     

Effective decrease in the exchange energy in <Emphasis Type="Italic">S</Emphasis>-(<Emphasis Type="Italic">FN</Emphasis>)-<Emphasis Type="Italic">S</Emphasis> Josephson structures

The critical current I _c of S-(FN)-S Josephson structures has been calculated as a function of the distance L between superconducting (S) electrodes using the Usadel quasiclassical equations for the case of specifying the supercurrent in the direction parallel to the interface between the ferromagnetic (F) and normal (N) films of the composite weak-link region. It has been shown that, owing to the interaction between F and N films, both the typical decrease scale I _c(L) and the period of the critical current oscillations can be much larger than the respective quantities for the SFS junctions. The conditions have been determined under which these lengths are on the order of the effective depth ζ_N of superconductivity penetration to a normal metal.     

<Emphasis Type="Italic">B</Emphasis>-meson production at Tevatron and the LHC in the Regge limit of quantum chromodynamics

We study the inclusive hadroproduction of B⁰, B⁺, and B_s⁰ mesons in the leading order in the parton Reggeization approach. We have described B-meson transverse momentumdistributionsmeasured in the central region of rapidity by the CDF Collaboration at Fermilab Tevatron and CMS Collaboration at LHC within uncertainties and without free parameters, applying Kimber–Martin–Ryskin unintegrated gluon distribution function in a proton.