Search

The large data sample of the ${B}_{c}$ meson collected at the LHC experiment and the HL-LHC experiment provides us the opportunity to study the ${B}_{c}$ decays and the related physics. In this paper, we investigate the effect of ${K}^{0}\ensuremath{-}{\overline{K}}^{0}$ mixing on the branching ratios, $CP$ violations and $CPT$ violations in the ${B}_{c}^{\ifmmode\pm\else\textpm\fi{}}\ensuremath{\rightarrow}{B}^{\ifmmode\pm\else\textpm\fi{}}{K}_{S,L}^{0}$ decays. We find that some of the ${B}_{c}^{\ifmmode\pm\else\textpm\fi{}}\ensuremath{\rightarrow}{B}^{\ifmmode\pm\else\textpm\fi{}}{K}_{S,L}^{0}\ensuremath{\rightarrow}{f}_{{B}^{\ifmmode\pm\else\textpm\fi{}}}{f}_{{K}_{S,L}^{0}}$ decay chains have large branching ratios, whose maximum value can exceed the order of ${10}^{\ensuremath{-}6}$, the minimum number of ${B}_{c}^{\ifmmode\pm\else\textpm\fi{}}$ events times efficiency for observing the decays at three standard deviations ($3\ensuremath{\sigma}$) level is about ${10}^{6}$. We study the $CP$ asymmetries in the ${B}_{c}^{\ifmmode\pm\else\textpm\fi{}}\ensuremath{\rightarrow}{B}^{\ifmmode\pm\else\textpm\fi{}}{K}_{S,L}^{0}$ decays and find that the $CP$ asymmetries can exceed the order of ${10}^{\ensuremath{-}3}$, which are dominated by ${K}^{0}\ensuremath{-}{\overline{K}}^{0}$ mixing. We give the most promising processes to observe the $CP$ violations and the ranges of the numbers of ${B}_{c}^{\ifmmode\pm\else\textpm\fi{}}$ events-times-efficiency needed to observe the $CP$ asymmetries at a significance of $3\ensuremath{\sigma}$ in these decays. We investigate the possibility to constraint the $CPT$ violation parameter $z$ in the ${B}_{c}^{\ifmmode\pm\else\textpm\fi{}}\ensuremath{\rightarrow}{B}^{\ifmmode\pm\else\textpm\fi{}}{K}_{S,L}^{0}\ensuremath{\rightarrow}{f}_{{B}^{\ifmmode\pm\else\textpm\fi{}}}{f}_{{K}_{S,L}^{0}}$ decays and give the most promising processes to constraint the parameter $z$.

The decays ${K}^{*}(892)\ensuremath{\rightarrow}{K}_{S,L}^{0}\ensuremath{\pi}$ can be used to study $CP$ violation and $CPT$ violation. The ${K}^{*}(892)$ (hereinafter referred to as ${K}^{*}$) meson can be produced via $J/\ensuremath{\psi}$ decays at BESIII. In this paper, we study $CP$ violation and ${K}_{S}^{0}\ensuremath{-}{K}_{L}^{0}$ asymmetry in the $J/\ensuremath{\psi}$ decays involving the ${K}^{*}$ meson in the final states and obtain the following results: ${\mathcal{A}}_{CP}(J/\ensuremath{\psi}\ensuremath{\rightarrow}{K}^{*}{f}_{J/\ensuremath{\psi}}\ensuremath{\rightarrow}{K}_{S}^{0}\ensuremath{\pi}{f}_{J/\ensuremath{\psi}})=(3.64\ifmmode\pm\else\textpm\fi{}0.04)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$, ${\mathcal{A}}_{CP}(J/\ensuremath{\psi}\ensuremath{\rightarrow}{K}^{*}{f}_{J/\ensuremath{\psi}}\ensuremath{\rightarrow}\phantom{\rule{0ex}{0ex}}{K}_{L}^{0}\ensuremath{\pi}{f}_{J/\ensuremath{\psi}})=(\ensuremath{-}3.32\ifmmode\pm\else\textpm\fi{}0.04)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$, and $R(J/\ensuremath{\psi}\ensuremath{\rightarrow}{K}^{*}{f}_{J/\ensuremath{\psi}}\ensuremath{\rightarrow}{K}_{S,L}^{0}\ensuremath{\pi}{f}_{J/\ensuremath{\psi}})=(3.51\ifmmode\pm\else\textpm\fi{}0.03)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$, $R(J/\ensuremath{\psi}\ensuremath{\rightarrow}{\overline{K}}^{*}{\overline{f}}_{J/\ensuremath{\psi}}\ensuremath{\rightarrow}{K}_{S,L}^{0}\ensuremath{\pi}{\overline{f}}_{J/\ensuremath{\psi}})=(\ensuremath{-}3.45\ifmmode\pm\else\textpm\fi{}0.03)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$. Based on two cases, the samples of ${10}^{10}$ and ${10}^{12}\text{ }\text{ }J/\ensuremath{\psi}$ events, we calculate the expected numbers of the observed signal events on the $CP$ violation and the ${K}_{S}^{0}\ensuremath{-}{K}_{L}^{0}$ asymmetry in the $J/\ensuremath{\psi}$ decays with ${K}^{*}$ meson in the final states, and we find that the BESIII experiment may be able to unambiguously observe $CP$ violation and ${K}_{S}^{0}\ensuremath{-}{K}_{L}^{0}$ asymmetry for each of these two cases. We study the possibility to constrain the $CPT$ violation parameter $z$ and discuss the sensitivity for the measurement of $z$ in $J/\ensuremath{\psi}$ decays with ${K}^{*}$ meson in the final states at BESIII. The sensitivity of the measurement of $z$ depends on the measured precision of the parameters ${m}_{L}\ensuremath{-}{m}_{S}$, ${\mathrm{\ensuremath{\Gamma}}}_{L}$, ${\mathrm{\ensuremath{\Gamma}}}_{S}$, $p$, and $q$ and the consistence between the values of ${t}_{0}$ and ${t}_{1}$ and the event selection criteria in experiment.

Motivated by recent anomalies in flavor changing neutral current $b\ensuremath{\rightarrow}s{\ensuremath{\ell}}^{+}{\ensuremath{\ell}}^{\ensuremath{-}}$ transitions, we study ${\mathcal{B}}_{1}\ensuremath{\rightarrow}{\mathcal{B}}_{2}{\ensuremath{\ell}}^{+}{\ensuremath{\ell}}^{\ensuremath{-}}(\ensuremath{\ell}=e,\ensuremath{\mu},\ensuremath{\tau})$ semileptonic weak decays with the SU(3) flavor symmetry, where ${\mathcal{B}}_{1,2}$ are the spin-$\frac{1}{2}$ baryons of single bottomed antitriplet ${T}_{b3}$, single charmed antitriplet ${T}_{c3}$, or light baryons octet ${T}_{8}$. Using the SU(3) irreducible representation approach, we first obtain the amplitude relations among different decay modes and then predict the relevant not-yet measured observables of ${T}_{b3}\ensuremath{\rightarrow}{T}_{8}{\ensuremath{\ell}}^{+}{\ensuremath{\ell}}^{\ensuremath{-}}$, ${T}_{c3}\ensuremath{\rightarrow}{T}_{8}{\ensuremath{\ell}}^{+}{\ensuremath{\ell}}^{\ensuremath{-}}$, and ${T}_{8}\ensuremath{\rightarrow}{T}_{8}^{\ensuremath{'}}{\ensuremath{\ell}}^{+}{\ensuremath{\ell}}^{\ensuremath{-}}$ decays. (a) We calculate the branching ratios of the ${T}_{b3}\ensuremath{\rightarrow}{T}_{8}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$ and ${T}_{b3}\ensuremath{\rightarrow}{T}_{8}{\ensuremath{\tau}}^{+}{\ensuremath{\tau}}^{\ensuremath{-}}$ decay modes in the whole ${q}^{2}$ region and in the different ${q}^{2}$ bins by the measurement of ${\mathrm{\ensuremath{\Lambda}}}_{b}^{0}\ensuremath{\rightarrow}{\mathrm{\ensuremath{\Lambda}}}^{0}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$. Many of them are obtained for the first time. In addition, the longitudinal polarization fractions and the leptonic forward-backward asymmetries of all ${T}_{b3}\ensuremath{\rightarrow}{T}_{8}{\ensuremath{\ell}}^{+}{\ensuremath{\ell}}^{\ensuremath{-}}$ decays are very similar to each other in certain ${q}^{2}$ bins due to the SU(3) flavor symmetry. (b) We analyze the upper limits of $\mathcal{B}({T}_{c3}\ensuremath{\rightarrow}{T}_{8}{\ensuremath{\ell}}^{+}{\ensuremath{\ell}}^{\ensuremath{-}})$ by using the experimental upper limits of $\mathcal{B}({\mathrm{\ensuremath{\Lambda}}}_{c}^{+}\ensuremath{\rightarrow}p{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}})$ and $\mathcal{B}({\mathrm{\ensuremath{\Lambda}}}_{c}^{+}\ensuremath{\rightarrow}p{e}^{+}{e}^{\ensuremath{-}})$, and find the experimental upper limit of $\mathcal{B}({\mathrm{\ensuremath{\Lambda}}}_{c}^{+}\ensuremath{\rightarrow}p{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}})$ giving the effective bounds on the relevant SU(3) flavor symmetry parameters. The predictions of $\mathcal{B}({\mathrm{\ensuremath{\Xi}}}_{c}^{0}\ensuremath{\rightarrow}{\mathrm{\ensuremath{\Xi}}}^{0}{e}^{+}{e}^{\ensuremath{-}})$ and $\mathcal{B}({\mathrm{\ensuremath{\Xi}}}_{c}^{0}\ensuremath{\rightarrow}{\mathrm{\ensuremath{\Xi}}}^{0}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}})$ will be different between the single-quark transition dominant contributions and the $W$-exchange dominant ones. (c) As for ${T}_{8}\ensuremath{\rightarrow}{T}_{8}^{\ensuremath{'}}{\ensuremath{\ell}}^{+}{\ensuremath{\ell}}^{\ensuremath{-}}$ decays, we analyze the single-quark transition contributions and the $W$-exchange contributions by using the two experimental measurements of $\mathcal{B}({\mathrm{\ensuremath{\Xi}}}^{0}\ensuremath{\rightarrow}{\mathrm{\ensuremath{\Lambda}}}^{0}{e}^{+}{e}^{\ensuremath{-}})$ and $\mathcal{B}({\mathrm{\ensuremath{\Sigma}}}^{+}\ensuremath{\rightarrow}p{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}})$, and give the branching ratio predictions by assuming either single-quark transition dominant contributions or the $W$-exchange dominant contributions. According to our predictions, some observables are accessible to the experiments at BESIII, LHCb and Belle-II.

Recently, several hints of lepton nonuniversality have been observed in the semileptonic B meson decays in terms of both in the neutral current ($b\ensuremath{\rightarrow}sl\overline{l}$) and charged current ($b\ensuremath{\rightarrow}cl\overline{{\ensuremath{\nu}}_{l}}$) transitions. Motivated by these inspiring results, we perform the analysis of the baryon decays ${\mathrm{\ensuremath{\Sigma}}}_{b}\ensuremath{\rightarrow}{\mathrm{\ensuremath{\Sigma}}}_{c}l\overline{{\ensuremath{\nu}}_{l}}$ and ${\mathrm{\ensuremath{\Omega}}}_{b}\ensuremath{\rightarrow}{\mathrm{\ensuremath{\Omega}}}_{c}l\overline{{\ensuremath{\nu}}_{l}}(l=e,\ensuremath{\mu},\ensuremath{\tau})$ which are mediated by $b\ensuremath{\rightarrow}cl\overline{{\ensuremath{\nu}}_{l}}$ transitions at the quark level, to scrutinize the nature of new physics (NP) in the model independent method. We first use the experimental measurements of $\mathcal{B}(B\ensuremath{\rightarrow}{D}^{(*)}l\overline{{\ensuremath{\nu}}_{l}})$, ${\mathrm{R}}_{{D}^{(*)}}$ and ${\mathrm{R}}_{J/\ensuremath{\psi}}$ to constrain the NP coupling parameters in a variety of scenarios. Using the constrained NP coupling parameters, we report numerical results on various observables related to the processes ${\mathrm{\ensuremath{\Sigma}}}_{b}\ensuremath{\rightarrow}{\mathrm{\ensuremath{\Sigma}}}_{c}l\overline{{\ensuremath{\nu}}_{l}}$ and ${\mathrm{\ensuremath{\Omega}}}_{b}\ensuremath{\rightarrow}{\mathrm{\ensuremath{\Omega}}}_{c}l\overline{{\ensuremath{\nu}}_{l}}$, such as the branching ratios, the ratio of branching fractions, the lepton side forward-backward asymmetries, the hadron and lepton longitudinal polarization asymmetries and the convexity parameter. We also provide the ${q}^{2}$ dependency of these observables and we hope that the corresponding numerical results in this work will be testified by future experiments.

The $a_0^0(980)-f_0(980)$ mixing is one of the most potential tools to learn about the nature of $a_0^0(980)$ and $f_0(980)$. Using the $f_0(980)$-$a_0^0(980)$ mixing intensity $\xi_{af}$ measured recently at BESIII, we calculate the the branching ratio of the the isospin violation decay $J/\psi \rightarrow\gamma\eta_c \rightarrow \gamma \pi^0 a_0^0(1450)\rightarrow \gamma \pi^0 a_0^0(980)f_0(500)\rightarrow \gamma \pi^0 f_0(980) f_0(500) \rightarrow \gamma \pi^0 \pi^+\pi^- \pi^+\pi^-$. The value of the branching ratio is found to be $O(10^{-6})$, which can be observed with $10^{10}$ $J/\psi$ events collected at BESIII. The narrow peak from the $f_0(980)$-$a_0^0(980)$ mixing in the $\pi^+\pi^-$ mass square spectrum can also be observed. In addition, we study the non-resonant decay $a_0^0(1450)\rightarrow f_0(980) \pi^+\pi^-(\text{non-resonant})$, which is dominated by the $a_0^0(980)$-$f_{0}(980)$ mixing. We find that the non-resonant decay $a_0^0(1450)\rightarrow f_0(980) \pi^+\pi^-$ and the decay $a_0^0(1450)\rightarrow f_0(980) f_0(500)$ can be combined to measure the mixing intensity $\xi_{af}$ in experiment. These decays are the perfect complement to the decay $\chi_{c1}\rightarrow f_{0}(980)\pi^{0}\to\pi^{+}\pi^{-}\pi^{0}$ which had been observed at BESIII, the observations of them will make the measurement of the mixing intensity $\xi_{af}$ more precisely.

Leptoquarks have been suggested to solve a variety of discrepancies between the expected and observed phenomenon. In this paper, we investigate the effects of scalar leptoquarks on the lepton flavor violating B meson rare decays which involve the quark level transition $b \to s {\ell }_{i}^{-} {\ell }_{j}^{+} (i \neq j)$ . The leptoquark parameter spaces are constrained by using the recently measured upper limits on $\mathcal {B}({B}_{s}^{0} \to {\ell }_{i}^{-} {\ell }_{j}^{+})$ and $\mathcal {B}(B \to K^{(*)} {\ell }_{i}^{-} {\ell }_{j}^{+})$ . Using such constrained leptoquark parameter spaces, some relevant physical quantities are predicted and we find that the constrained new physics parameters in the leptoquark model have very obvious effects on the relevant physical quantities. With future measurements of observables in $B \to K^{(*)} {\ell }_{i}^{-} {\ell }_{j}^{+}$ decays at the LHCb, more and more differentiated from the other new physics explanations could be tested.

Many decays of light baryons consisting of light $u,d,s$ quarks have been measured, and these measurements will help us to understand the decay properties of light baryons. In this work, we study two-body nonleptonic weak decays of light baryon octet $(T_8)$ and baryon decuplet $(T_{10})$ by the topological diagram approach (TDA) under the SU(3) flavor symmetry for the first time. We find that (1) the TDA and the SU(3) irreducible representation approach (IRA) match consistently in $T_{10}\to T^{(')}_{8,10}P_8$ ($P_8$ is the light pseudoscalar meson octet); (2) almost all relevant not-yet-measured $\mathcal{B}(T_{10}\to T_8 P_8)$ may be predicted by using three experimental data of $\mathcal{B}(\Omega^-\to \Xi^0\pi^-,\Xi^-\pi^0,\Lambda^0K^-)$, and the upper limits of $\mathcal{B}(T_{10}\to T{'}_{10}\pi^-)$ may be obtained from the experimental upper limit of $\mathcal{B}(\Omega^-\to \Xi^{*0}\pi^-)$ by both the TDA and the IRA together, nevertheless, all new predicted branching ratios are too small to br reached in current experiments; (3) $T_8\to T'_8 P_8$ decays are quite complex in terms of the TDA, and we find that W-exchange diagrams give large and even dominant contributions by using relevant experimental data and the isospin relations., Comment: 14 pages, 1 figure

The semileptonic decays and two-body nonleptonic decays of light baryon octet ($T_8$) and decuplet ($T_{10}$) consisting of light $u,d,s$ quarks are studied with the SU(3) flavor symmetry in this work. We obtain the amplitude relations between different decay modes by the SU(3) irreducible representation approach, and then predict relevant branching ratios by present experimental data within $1 \sigma$ error. We find that the predictions for all branching ratios except $\mathcal{B}(\Xi\rightarrow \Lambda^0\pi)$ and $\mathcal{B}(\Xi^*\rightarrow \Xi\pi)$ are in good agreement with present experimental data, that implies the neglected $C_+$ terms or SU(3) breaking effects might contribute at the order of a few percent in $\Xi\rightarrow \Lambda^0\pi$ and $\Xi^*\rightarrow \Xi\pi$ weak decays. We predict that $\mathcal{B}(\Xi^{-}\rightarrow \Sigma^0\mu^-\bar{\nu}_\mu)=(1.13\pm0.08)\times10^{-6}$, $\mathcal{B}(\Xi^{-}\rightarrow\Lambda^0\mu^-\bar{\nu}_\mu)=(1.58\pm0.04)\times10^{-4}$, $\mathcal{B}(\Omega^-\rightarrow\Xi^0\mu^-\bar{\nu}_\mu)=(3.7\pm1.8)\times10^{-3}$, $\mathcal{B}(\Sigma^-\rightarrow \Sigma^0e^-\bar{\nu}_e)=(1.35\pm0.28)\times10^{-10}$, $\mathcal{B}(\Xi^-\rightarrow \Xi^0e^-\bar{\nu}_e)=(4.2\pm2.4)\times10^{-10}$. We also study $T_{10}\to T_8 P_8$ weak, electromagnetic or strong decays. Some of these decay modes could be observed by the BESIII, LHCb and other experiments in the near future. Due to the very small life times of $\Sigma^0$, $\Xi^{*0,-}$, $\Sigma^{*0,-}$ and $\Delta^{0,-}$, the branching ratios of these baryon weak decays are only at the order of $\mathcal{O}(10^{-20}-10^{-13}$), which are too small to be reached by current experiments. Furthermore, the longitudinal branching ratios of $T_{8A} \to T_{8B} \ell^- \bar{\nu}_\ell~(\ell=\mu,e)$ decays are also given., Comment: 23 pages, 4 figures

The weak and electromagnetic radiative baryon decays of octet $T_{8}$, decuplet $T_{10}$, single charmed anti-triplet $T_{c3}$ and sextet $T_{c6}$, single heavy bottomed anti-triplet $T_{b3}$ and sextet $T_{b6}$ are investigated by using SU(3) flavor symmetry irreducible representation approach. We analyze the contributions from a single quark transition $q_1\to q_2\gamma$ and $W$ exchange transitions, and find that the amplitudes could be easily related by SU(3) flavor symmetry in the $T_{b3,b6}$ weak radiative decays, $T_{c3,c6}$ weak radiative decays, $T_{10}\to T_{8}\gamma $ weak decays, $T_{10}\to T'_{10}\gamma $ weak decays and $T_{10}\to T_{8}\gamma $ electromagnetic decays. Nevertheless, the amplitude relations are a little complex in the $T_{8}\to T'_{8}\gamma$ and $T_{8}\to T_{10}\gamma$ weak decays due to quark antisymmetry in $T_{8}$ and $W$ exchange contributions. Predictions for branching ratios of $\Lambda^{0}_b\to n\gamma$, $\Xi^{-}_b\to \Xi^-\gamma$, $\Xi^{-}_b\to \Sigma^-\gamma$, $\Xi^{0}_b\to \Sigma^0\gamma$, $\Xi^{0}_b\to \Lambda^0\gamma$, $\Xi^{0}_b\to \Xi^0\gamma$, $\Xi^{*}\to \Xi\gamma$, $\Sigma^{*0}\to \Sigma^{0}\gamma$, $\Delta^0\to n\gamma$ and $\Delta^+\to p\gamma$ are given. The results in this work can be used to test SU(3) flavor symmetry approach in the radiative baryon decays by the future experiments at BESIII, LHCb and Belle-II., Comment: 17 pages, 2 figures

Almost all branching ratios and longitudinal polarization fractions of the double charm decays $B_{(s)} \to D_{(s)}^{(*)} D_{s}^{(*)}$ have been measured, and the experimental central value of $f_{L}({B^{0}_{s}}\to D^{*+}_{s}D^{*-}_{s})$ is quite small comparing to its Standard Model prediction. We study the fourth generation quark contributions to the double charm decays $B_{(s)} \to D_{(s)}^{(*)} D_{s}^{(*)}$ . We find that the loop diagrams involving the fourth generation quark t′ have great effects on all branching ratios and CP asymmetries, which are very sensitive to the fourth generation parameter $\lambda ^{s}_{t^{\prime }}$ and $\phi _{t^{\prime }}$ . Nevertheless, the experimental measurements of all branching ratios can not give effective constraints on relevant new physics parameters. In addition, they have no obvious effect on the relevant polarization fractions. These results could be used to search for the fourth heavy quark t′ via its indirect manifestations in loop diagrams.

Using measured branching fraction of the decay $J/\psi \rightarrow\eta Y(2175))\rightarrow\eta\phi f_0(980)\rightarrow\eta\phi\pi^+\pi^{-}$ from the BESIII experiment, we estimate branching fraction of $J/\psi \rightarrow\eta Y(2175))\rightarrow\eta\phi f_0(980)\rightarrow\eta\phi\eta\pi^{0}$ decay, which proceeds via the $f_0(980)$-$a_0^0(980)$ mixing and the $\pi^0$-$\eta$ mixing. The branching fraction is predicted to be about $O(10^{-6})$, which can be accessed with $10^{10}$ $J/\psi$ events collected at the BESIII. The decay is dominated by the contribution from $f_0(980)$-$a_0^0(980)$ mixing. We find that the interference between the amplitudes due to $f_0(980)$-$a_0^0(980)$ mixing and that due to $\pi^0$-$\eta$ mixing is destructive. The branching fraction can be decreased by about $10\%$ owing to the interference effect. We also study the $\eta\pi^0$ mass squared spectrum, and find that a narrow peak due to the $f_0(980)$-$a_0^0(980)$ mixing in the $\eta\pi^0$ mass squared spectrum should be observed. The observation of this decay in experiment will be helpful to determine the $f_0(980)$-$a_0^0(980)$ mixing intensity and get information about the structures of the light scalar mesons.

Motivated by recent results from the LHCb, BABAR and Belle collaborations on B\to D^{(*)}\ell^-\bar{\nu}_\ell decays, which significantly deviate from the Standard Model and hint the possible new physics beyond the Standard Model, we probe the R-parity violating supersymmetric effects in B^-_c\to \ell^-\bar{\nu}_\ell and B\to D^{(*)}\ell^-\bar{\nu}_\ell decays. We find that (i) \mathcal{B}(B^-_c\to e^- \bar{\nu}_e) and \mathcal{B}(B^-_c\to\mu^-\bar{\nu}_\mu) are sensitive to the constrained slepton exchange couplings; (ii) the normalized forward-backward asymmetries of B\to De^-\bar{\nu}_{e} decays have been greatly affected by the constrained slepton exchange couplings, and their signs could be changed; (iii) all relevant observables in the exclusive b\to c\tau^-\bar{\nu}_\tau decays and the ratios \mathcal{R}(D^{(*)}) are sensitive to the slepton exchange coupling, \mathcal{R}(D^*) could be enhanced by the constrained slepton exchange coupling to reach each 95\% confidence level experimental range from BABAR, Belle and LHCb, but it could not reach the lower limit of the 95\% confidence level experimental average. Our results in this work could be used to probe R-parity violating effects, and will correlate with searches for direct supersymmetric signals at the running LHCb and the forthcoming Belle-II.

Community detection is of considerable importance for understanding both the structure and function of complex networks. In this paper, we introduced the general procedure of the community detection algorithms using global and local structural information, where the edge betweenness and the local similarity measures respectively based on local random walk dynamics and local cyclic structures were used. The algorithms were tested on artificial and real-world networks. The results clearly show that all the algorithms have excellent performance in the tests and the local similarity measure based on local random walk dynamics is superior to that based on local cyclic structures.

Epoxy resin structural adhesives modified by flexible curing agent. Dependening on the mechanical properties of epoxy resins on the flexible curing agent content was studied. The impact fracture toughness was discussed in terms of fracture surface fractography.

Epoxy resin adhesives are widely used in various sectors, particularly in the aerospace and automotive industries. However, the solidification of the three-dimensional network structure of pure epoxy resin, which causes greater density and brittleness, results in poor system resilience. With the ultimate goal of improving the resilience of epoxy resin, nano-sized SiO2particles were introduced to improve the adhesion strength of both modified and unmodified epoxy adhesive. The results indicated increases of shearing strength from 16.66-Mpa to 18.01 -Mpa, impact strength from 15.4-kJ/m2 to 33.68-kJ/m2, and flexural strength from 70.5-Mpa to 80.94 Mpa.

A superplasticizer (WPS) was synthesized from waste plexiglas and sodium allysulfonate in this paper. Poly (methyl methacrylate-co-ethyl acrylate) grafling sodium allysulfonate (PMMA-g-AS) was prepared through reactive extrusion in self-single screw extruder and hydrolysis reaction. The structures of the WPS was characterized by FT-IR spectrometer. The results show that structure of the WPS are clear. By using UV-visible adsorption spectrophotometer, micro-electrophoresis potential analyzer, and X-ray photo spectroscopy, the adsorption characteristics and surface electrochemical properties of WPS were studied in comparison with traditional naphthalene sulfonated formaldehyde condensates (FDN) whose dispersion ability mainly depends on electrostatic repulsive forces. The results indicated that the adsorption behavior of WPS on gypsum particles follows a Langmuir isothermal adsorption model with an adsorption heat of 18.79 kJ/mol and an adsorption layer thickness of 17. 52 nm. Adsorption isotherm suggested that Langmiur single layer adsorption occurred during the process of adsorption of WPS and FDN on gypsum particles.

In this study, by using UV-visible adsorption spectrophotometer, ζ-potential analyzer and X-ray photo spectroscopy, the adsorption characteristics and surface electrochemical properties of WPS were studied in comparison with traditional naphthalene sulfonated formaldehyde condensates (FDN) whose dispersion ability mainly depends on electrostatic repulsive forces. WPS was prepared through free radical copolymerization in self-Single screw reactive extruder and synthesized from waste plexiglas and vinyl monomers by way of special extrusion modification. The results show that the adsorption of WPS and FDN on cement particle surface approximately conforms to Langmuir’s adsorption isotherm. The adsorption of WPS belongs to physical adsorption and its saturated adsorbed quantity was 5.38mg/g. When the dosage of WPS was 1 wt.% of cement, the thickness of the adsorption layer on the surface of cement particles was 61.2 nm. The ζ-potential of cement particle with WPS changed from positive (15 mV) to negative (-64.74mV) with its concentration increasing from 0 to 20 g/L and decreased from -65.19 to-39.82 mV (reducing by 38.9%) with its concentration of 10 g/L within 60 h.

Single factor experiment was used to investigate neutral deinking technology of old magazine paper (OMG) by self-compounded NTM-2 deinking agent. Olympus inverted biological microscope were used to research distribution state of ink particles in the secondary pulp before and after deinking treatment. Scanning electron microscopy (SEM) was used to analyze fiber surface changing during neutral deinking and ink particles dispersing behaviors in the paper. The results showed that NTM-2 deinking agent had a good deinking effect to OMG, optimum operation conditions of neutral deinking was NTM-2 0.5%, deinking temperature 50°C, deinking time 40min, repulper time 25s, pulp consistence 1.0%, and floatation time 6 min. Under these conditions, brightness of the deinked pulp increased 8.4%SBD, and the ink removal efficiency reached by 90%. Olympus inverted biological microscope images showed that there were a large number of ink particles in the un-treated pulp, and these ink particles integrated with fibers tightly. After treated by neutral deinking, most of ink particles were separated from the fiber, dispersed and suspended in the pulp evenly. SEM images indicated that there were little ink particles in the secondary paper, the fiber surface turned more smoother, and the clean degree would nearly corresponding to the effect of alkaline deinking.

Layered double hydroxides (LDHs), consist of cationic brucite-like layers and exchangeable interlayer anions. In this thesis LDHs consist of brucite-like layers of zinc hydroxide, with the exchanging propertity of interlayer anions in hydrotalcites, used Mg/Zn/Al-LDH as precursor to prepare the theophylline intercalation assembly hydrotalcites to obtain supramolecular complex for the first time by co-precipitation under a nitrogen atmosphere, determined the reaction conditions and influential factors of the synthesis of theophylline-pillared hydrotalcites, and tested its sustained-release performance in different media. The product has been characterized by powder X-ray diffraction (XRD), FT-IR spectroscopy, uv-vis spectrophotometer and thermogravimetry-Differential thermal analysis (TG-DTA) . Results demonstrated that : Through co-precipitation intercalation methods, with molar ratio of Mg/Zn/Al/ theophylline being 3:1:1:2, co-precipitation medium pH9, crystallization temperature 80 °C and crystallization time 12h can obtain the clear chemical composition and good crystallization of inorganic - organic hybrid-type drugs hydrotalcites. In addition, according to Pharmacopoeia measured the release rate of theophylline-LDH in the different media including distilled water,0.9%saline,simulated intestinal fluid (pH7.4 phosphate buffer) by UV spectrophotometry, Theophylline pillared hydrotalcite has a certain release in the media above all. And calculated the release of intercalation theophylline, lay the foundation for the further clinical application.

In the offset process, ink penetration performance has extremely important influence on the quality of printed products. Ink penetration behavior and ink transfer volume on the offset paper surface were researched with the aid of IGT printability tester (AIC2-5) in the conditions of temperature 20±3°C and humidity of 60 ± 5%. Effect of different printing pressure and printing speed on the ink penetration depth was discussed, and at the same time, the depth was measured by GX71 Inverted Metallurgical Microscope. The results showed that, with the increasing of printing pressure, the changes of ink penetration depth and the ink transfer volume on offset paper surface were increased firstly and then decreased. When printing pressure was 400N, the ink penetration depth reached the maximum 71.67μm and the ink transfer volume reached the maximum too. With the enhancing of printing speed, ink penetration depth and ink transfer volume would be decreased gradually. The study also found that ink penetration behavior had certain influence on the ink color forming properties. For the offset paper used in this experiment, when ink penetration depth was 60.0μm~63.0μm, the print had high ink color intensity and color efficiency. When the ink penetration depth was too deep, ink color intensity and color efficiency was significantly reduced, while the color hue error would be increased, the print ink color turned shallow.

We present a complete study of R-parity violating supersymmetric effects in thirteen exclusive and inclusive semi-leptonic b → ( s , d ) ν ν ¯ decays; B u + → K ( ∗ ) + ν ν ¯ , B d 0 → K ( ∗ ) 0 ν ν ¯ , B s 0 → ϕ ν ν ¯ , B d 0 → π 0 ( ρ 0 ) ν ν ¯ , B u + → π + ( ρ + ) ν ν ¯ , B s 0 → K ( ∗ ) 0 ν ν ¯ and B → X s , d ν ν ¯ decay modes. We find those thirteen modes are very sensitive to the constrained R-parity violating couplings. We derive stringent bounds on relevant R-parity violating couplings, which are based on all existent experimental upper limits of involved semi-leptonic decays. In addition, we also investigate the sensitivities of the branching ratios and di-neutrino invariant mass spectra to the survived R-parity violating coupling spaces. Since the experimental bounds would become much better soon through super- B , we expect that future experiments will greatly strengthen our bounds.

We apply the variational method to obtain the universal and analytical lower bounds for parameter precision in some noisy systems. We first derive a lower bound for phase precision in lossy optical interferometry at non-zero temperature. Then we consider the effect of both amplitude damping and phase diffusion on phase-shift precision. At last, we extend the constant phase estimation to the case of continuous fluctuating phase estimation, and find that due to photon losses the corresponding mean square error transits from the stochastic Heisenberg limit to the stochastic standard quantum limit as the total photon flux increases., 6 pages, 3 figures

We study the branching ratios, the direct CP asymmetries in $B\to K^{(*)}\bar{K}^{(*)}$ decays and the polarization fractions of $B\to K^{*}\bar{K}^{*}$ decays by employing the QCD factorization in the minimal supersymmetric standard model with R-parity violation. We derive the new upper bounds on the relevant R-parity violating couplings from the latest experimental data of $B\to K^{(*)}\bar{K}^{(*)}$, and some of these constraints are stronger than the existing bounds. Using the constrained parameter spaces, we predict the R-parity violating effects on the other quantities in $B\to K^{(*)}\bar{K}^{(*)}$ decays which have not been measured yet. We find that the R-parity violating effects on the branching ratios and the direct $CP$ asymmetries could be large, nevertheless their effects on the longitudinal polarizations of $B\to K^{*}\bar{K}^{*}$ decays are small. Near future experiments can test these predictions and shrink the parameter spaces., Comment: 31 pages with 10 figures

We investigate the exact dynamics of the damped quantum harmonic oscillator under the (un)correlated initial conditions. We generalize the master equation to the cases of arbitrary factorized state and/or Gaussian state. For the factorized Gaussian state, we demonstrate that the effects of the initial oscillator-bath correlation are unnoticeable for the evolutions of variances, but can become remarkable for the evolutions of mean values even at high temperature. We also show that the initial dip during the purity evolution always shows up for the factorized initial state, but can disappear for some correlated non-factorizable initial state. Finally, we study the effects of repeated measurements on the time evolution of the damped oscillator. The comparison with the weak coupling results indicates that even for an intermediate coupling, they can give quite different transient behaviors.

The rare decays ${B}_{s}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$ and $B\ensuremath{\rightarrow}{K}^{(*)}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$ are sensitive to new particles and couplings via their interferences with the standard model contributions. Recently, the upper bound on $\mathcal{B}({B}_{s}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}})$ has been improved significantly by the CMS, LHCb, CDF, and D0 experiments. Combining with the measurements of $\mathcal{B}(B\ensuremath{\rightarrow}{K}^{(*)}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}})$, we derive constraints on the relevant parameters of the minimal supersymmetic standard model with and without $R$ parity, and examine their contributions to the dimuon forward-backward asymmetry in $B\ensuremath{\rightarrow}{K}^{*}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$ decay. We find that (i) the contribution of $R$-parity violating coupling products ${\ensuremath{\lambda}}_{2i2}^{\ensuremath{'}}{\ensuremath{\lambda}}_{2i3}^{\ensuremath{'}*}$ due to squark exchange is comparable with the theoretical uncertainties in $B\ensuremath{\rightarrow}K{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$ decay, but still could be significant in $B\ensuremath{\rightarrow}{K}^{*}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$ decay and could account for the forward-backward asymmetry in all dimuon invariant mass regions; (ii) the constrained mass insertion $({\ensuremath{\delta}}_{LL}^{u}{)}_{23}$ could have a significant contribution to $d{\mathcal{A}}_{\mathrm{FB}}(B\ensuremath{\rightarrow}{K}^{*}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}})/ds$, and such effects are favored by the recent results of the Belle, CDF, and LHCb experiments.

Recent results from CDF and D0 collaborations favor a large $CP$ asymmetry in ${B}_{s}^{0}\ensuremath{-}{\overline{B}}_{s}^{0}$ mixing, while the standard model prediction is very small. Such a large phase may imply sizable new physics effects in ${B}_{s}^{0}\ensuremath{-}{\overline{B}}_{s}^{0}$ mixing. We compute the gluino-mediated supersymmetry contributions to ${B}_{s}^{0}\ensuremath{-}{\overline{B}}_{s}^{0}$ mixing, ${B}_{s}\ensuremath{\rightarrow}{K}^{(*)\ensuremath{-}}{K}^{(*)+}$ and $B\ensuremath{\rightarrow}{X}_{s}\ensuremath{\gamma}$ decays in the frame of the mass insertion approximation. Combining the constraints of $\ensuremath{\Delta}{M}_{s},\ensuremath{\Delta}{\ensuremath{\Gamma}}_{s},{\ensuremath{\phi}}_{s}^{J/\ensuremath{\psi}\ensuremath{\phi}}$, $\mathcal{B}({B}_{s}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{K}^{+})$ and $\mathcal{B}(B\ensuremath{\rightarrow}{X}_{s}\ensuremath{\gamma})$, we find that the effects of the constrained LL and RR insertions in ${B}_{s}\ensuremath{\rightarrow}{K}^{(*)\ensuremath{-}}{K}^{(*)+}$ decays are small because of the absence of gluino mass enhancement. For ${m}_{\stackrel{\texttildelow{}}{g}}^{2}/{m}_{\stackrel{\texttildelow{}}{q}}^{2}=9$, the constrained LR insertion can provide sizable contributions to all observables of ${B}_{s}\ensuremath{\rightarrow}{K}^{(*)\ensuremath{-}}{K}^{(*)+}$ decays except ${\mathcal{A}}_{CP}^{\mathrm{dir}}({B}_{s}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{K}^{+})$, and many observables are sensitive to the modulus and the phase of the LR insertion parameter. Near future experiments at Fermilab Tevatron and CERN LHC-b can test these predictions and shrink/reveal the mass insertion parameter spaces.