Exploring HVV amplitudes with CP violation using decomposition and the on-shell scattering amplitude method

\begin{document}$ CP $\end{document} violation may play an important role in baryogenesis in the early universe and should be examined comprehensively at colliders. We study the \begin{document}$ CP $\end{document} properties of \begin{document}$ HVV $\end{document} vertexes between Higgs and gauge boson pairs by defining a \begin{document}$ CP $\end{document} violation phase angle ξ, which indicates the mixture of \begin{document}$ CP $\end{document}-even and \begin{document}$ CP $\end{document}-odd Higgs states in \begin{document}$ HVV $\end{document} in new physics. A series of \begin{document}$ HVV $\end{document} amplitudes, \begin{document}$ H\to\gamma\gamma, H\to\gamma V\to \gamma \ell\ell $\end{document}, and \begin{document}$ H\to VV\to 4\ell $\end{document}, with a \begin{document}$ CP $\end{document} phase angle are studied systematically to explicitly explain why \begin{document}$ CP $\end{document} violation can only be probed independently in the \begin{document}$ 4\ell $\end{document} process. We obtain a novel amplitude decomposition relation that illustrates that if two preconditions (multilinear momentum dependent vertexes, and the current \begin{document}$ J_\mu $\end{document} of \begin{document}$ V\to \ell^+ \ell^- $\end{document} is formally proportional to a photon's polarization vector) are satisfied, a higher-point amplitude can be decomposed into a summation of a series of lower-point amplitudes. As a practical example, the amplitude of the \begin{document}$ H\to\gamma V\to \gamma \ell\ell $\end{document} and \begin{document}$ H\to VV\to 4\ell $\end{document} processes can be decomposed into a summation of many \begin{document}$ H\to\gamma\gamma $\end{document} amplitudes. We calculate these amplitudes in the framework of the on-shell scattering amplitude method, considering both massless and massive vector gauge bosons with the \begin{document}$ CP $\end{document} violation phase angle. The above two approaches provide consistent results and clearly reveal the \begin{document}$ CP $\end{document} violation ξ dependence in the amplitudes.     

Insights into the nature of X(3872) through B meson decays

We study the \begin{document}$ B_{c,u,d}\to X(3872)P $\end{document} decays in the perturbative QCD (PQCD) approach, involving the puzzling resonance \begin{document}$ X(3872) $\end{document}, where P represents a light pseudoscalar meson (K or π). Assuming \begin{document}$ X(3872) $\end{document} to be a \begin{document}$ 1^{++} $\end{document} charmonium state, we obtain the following results. (a) The branching ratios of the \begin{document}$ B^+_c\to X(3872)\pi^+ $\end{document} and \begin{document}$ B^+_c\to X(3872) K^+ $\end{document} decays are consistent with the results predicted by the covariant light-front approach within errors; however, they are larger than those given by the generalized factorization approach. (b) The branching ratio of the \begin{document}$ B^+\to X(3872)K^+ $\end{document} decay is predicted as \begin{document}$ (3.8^{+1.1}_{-1.0})\times10^{-4} $\end{document}, which is smaller than the previous PQCD calculation result but still slightly larger than the upper limits set by Belle and BaBar. Hence, we suggest that the\begin{document}$ B^{0,+}\to X(3872)K^{0,+} $\end{document} decays should be precisely measured by the LHCb and Belle II experiments to help probe the inner structure of \begin{document}$ X(3872) $\end{document}. (c) Compared with the \begin{document}$ B_{u,d}\to X(3872)K $\end{document}decays, the \begin{document}$ B_{u,d}\to X(3872)\pi $\end{document} decays have significantly smaller branching ratios, which drop to values as low as \begin{document}$ 10^{-6} $\end{document}. (d) The direct CP violations of these considered decays are small (\begin{document}$ 10^{-3}\sim 10^{-2} $\end{document}) because the penguin contributions are loop suppressed compared to the tree contributions. The mixing-induced CP violation of the \begin{document}$ B\to X(3872)K^0_S $\end{document} decay is highly consistent with the current world average value \begin{document}$ \sin2\beta=(69.9\pm1.7)$\end{document}%. Experimentally testing the results for the branching ratios and CP violations, including the implicit \begin{document}$S U(3)$\end{document} and isospin symmetries of these decays, helps probe the nature of \begin{document}$ X(3872) $\end{document}.     

Direct CP violation of three body decay processes from the resonance effect

The physical state of \begin{document}$ \rho-\omega-\phi $\end{document} mesons can be mixed using the unitary matrix. The decay processes \begin{document}$ \omega \rightarrow \pi^{+}\pi^{-} $\end{document} and \begin{document}$ \phi \rightarrow \pi^{+}\pi^{-} $\end{document} originate from isospin symmetry breaking. The \begin{document}$ \rho-\omega $\end{document}, \begin{document}$ \rho-\phi $\end{document}, and \begin{document}$ \omega-\phi $\end{document} interferences lead to a resonance contribution to produce strong phases. \begin{document}$ CP $\end{document} violation is considered from isospin symmetry breaking due to the new strong phase of the first order. \begin{document}$ CP $\end{document} violation can be enhanced greatly for the decay process \begin{document}$ B^{0}\rightarrow \pi^+\pi^{-}\eta^{(')} $\end{document} when the invariant masses of \begin{document}$ \pi^+\pi^{-} $\end{document} pairs are in the area around the \begin{document}$ \omega $\end{document} resonance range and \begin{document}$ \phi $\end{document} resonance range in perturbative QCD. We also discuss the possibility of searching for the predicted \begin{document}$ CP $\end{document} violation at the LHC.     

Neutron skin thickness of 90Zr and symmetry energy constrained by charge exchange spin-dipole excitations

The charge exchange spin-dipole (SD) excitations of \begin{document}$ ^{90} $\end{document}Zr are studied using the Skyrme Hartee-Fock plus proton-neutron random phase approximation with SAMi-J interactions. The experimental value of the model-independent sum rule obtained from the SD strength distributions of \begin{document}$ ^{90} $\end{document}Zr(p, n)\begin{document}$ ^{90} $\end{document}Nb and \begin{document}$ ^{90} $\end{document}Zr(n, p)\begin{document}$ ^{90} $\end{document}Y is used to deduce the neutron skin thickness. The neutron skin thickness \begin{document}$ \Delta r_{np} $\end{document} of \begin{document}$ ^{90} $\end{document}Zr is extracted as \begin{document}$ 0.083\pm0.032 $\end{document} fm, which is similar to the results of other studies. Based on the correlation analysis of the neutron skin thickness \begin{document}$ \Delta r_{np} $\end{document} and the nuclear symmetry energy J as well as its slope parameter L, a constraint from the extracted \begin{document}$ \Delta r_{np} $\end{document} leads to the limitation of J to \begin{document}$ 29.2 \pm 2.6 $\end{document} MeV and L to \begin{document}$ 53.3 \pm 28.2 $\end{document} MeV.     

Investigating S-wave bound states composed of two pseudoscalar mesons

In this study, we systematically investigated two-pseudoscalar meson systems with the Bethe-Salpeter equation in the ladder and instantaneous approximations. By solving the Bethe-Salpeter equation numerically with the kernel containing the one-particle exchange diagrams, we found that the \begin{document}$ K\bar{K} $\end{document}, \begin{document}$ DK $\end{document}, \begin{document}$ B\bar{K} $\end{document}, \begin{document}$ D\bar{D} $\end{document}, \begin{document}$ B\bar{B} $\end{document}, \begin{document}$ BD $\end{document}, \begin{document}$ D\bar{K} $\end{document}, \begin{document}$ BK $\end{document}, and \begin{document}$ B\bar{D} $\end{document} systems with \begin{document}$ I=0 $\end{document} can exist as bound states. We also studied the contributions from heavy meson (\begin{document}$ J/\psi $\end{document} and \begin{document}$\Upsilon $\end{document}) exchanges and found that the contributions from heavy meson exchanges cannot be ignored.     

Search for Majoron at the COMET experiment

A new Goldstone particle named Majoron is introduced in order to explain the origin of neutrino mass via some new physics models assuming that neutrinos are Majorana particles. By expanding the signal region and using likelihood analysis, it becomes possible to search for Majoron using experiments originally designed to search for \begin{document}$ \mu-e $\end{document} conversion. For the COMET experiment, the sensitivity of process \begin{document}$ \mu \rightarrow eJ $\end{document} is able to reach \begin{document}$ {\cal{B}}(\mu \rightarrow eJ)=2.3\times 10^{-5} $\end{document} in Phase-I and \begin{document}$ O(10^{-8}) $\end{document} in Phase-II. Meanwhile, the sensitivities to search for Majoron in future experiments are also discussed in this article.     

Systematic calculations of cluster radioactivity half-lives in trans-lead nuclei

In the present work, based on the Wentzel-Kramers-Brillouin (WKB) theory, considering the cluster preformation probability (\begin{document}$ P_{c} $\end{document}), we systematically investigate the cluster radioactivity half-lives of 22 trans-lead nuclei ranging from ²²¹Fr to ²⁴²Cm. When the mass number of the emitted cluster \begin{document}$ A_{c} $\end{document} \begin{document}$ < $\end{document} 28, \begin{document}$P_{c} $\end{document} is obtained by the exponential relationship of \begin{document}$ P_{c} $\end{document} to the α decay preformation probability (\begin{document}$ P_{\alpha} $\end{document}) proposed by R. Blendowskeis \begin{document}$ et $\end{document} \begin{document}$ al. $\end{document} [Phys. Rev. Lett. 61, 1930 (1988)], while \begin{document}$ P_{\alpha} $\end{document} is calculated through the cluster-formation model (CFM). When \begin{document}$ A_{c} $\end{document} \begin{document}$ \ge $\end{document} 28, \begin{document}$ P_{c} $\end{document} is calculated through the charge-number dependence of \begin{document}$ P_{c} $\end{document} on the decay products proposed by Ren \begin{document}$ et $\end{document} \begin{document}$ al. $\end{document} [Phys. Rev. C 70, 034304 (2004)]. The half-lives of cluster radioactivity have been calculated by the density-dependent cluster model [Phys. Rev. C 70, 034304 (2004)] and by the unified formula of half-lives for alpha decay and cluster radioactivity [Phys. Rev. C 78, 044310 (2008)]. For comparison, a universal decay law (UDL) proposed by Qi \begin{document}$ et $\end{document} \begin{document}$ al. $\end{document} [Phys. Rev. C 80, 044326 (2009)], a semi-empirical model for both α decay and cluster radioactivity proposed by Santhosh [J. Phys. G: Nucl. Part. Phys. 35, 085102 (2008)], and a unified formula of half-lives for alpha decay and cluster radioactivity [Phys. Rev. C 78, 044310 (2008)] are also used. The calculated results of our work, Ni's formula , and the UDL can well reproduce the experimental data and are better than those of Santhosh's model. In addition, we extend this model to predict the half-lives for 51 nuclei, whose cluster radioactivity is energetically allowed or observed but not yet quantified in NUBASE2020.     

Cosmological imprints of Dirac neutrinos in a keV-vacuum 2HDM

The Dirac neutrino masses could be simply generated by a neutrinophilic scalar doublet with a vacuum being dramatically different from the electroweak one. While the case with an eV-scale vacuum has been widely explored previously, we exploit in this work the desert where the scalar vacuum is of \begin{document}$\mathcal{O}(\mathrm{keV})$\end{document} scale. In this regime, there would be rare hope to probe the keV-vacuum neutrinophilic scalar model via the lepton-flavor-violating processes, which makes it distinguishable from the widely considered eV-scale vacuum. Although such a keV-vacuum scenario is inert in the low-energy flavor physics, we show that the baryogenesis realized via the lightest Dirac neutrino can be a natural candidate in explaining the baryon asymmetry of the Universe. Furthermore, the Dirac neutrinos with a keV-vacuum scalar can generate a shift of the effective neutrino number within the range \begin{document}$0.097\leqslant \Delta N_{\rm eff}\leqslant 0.112$\end{document}, which can be probed by the future Simons Observatory experiments. In particular, the model with a minimal value \begin{document}$\Delta N_{\rm eff}=0.097$\end{document} can already be falsified by the future CMB Stage-IV and Large Scale Structure surveys, providing consequently striking exploratory avenues in the cosmological regime for such a keV-vacuum scenario.     

Nonextensive effects on QCD chiral phase diagram and baryon-number fluctuations within Polyakov-Nambu-Jona-Lasinio model

In this paper, a version of the Polyakov-Nambu-Jona-Lasinio (PNJL) model based on nonextensive statistical mechanics is presented. This new statistics summarizes all possible factors that violate the assumptions of the Boltzmann-Gibbs (BG) statistics to a dimensionless nonextensivity parameter q. Thus, when q tends to 1, it returns to the BG case. Within the nonextensive PNJL model, we found that as q increases, the location of the critical end point (CEP) exhibits non-monotonic behavior. That is, for \begin{document}$ q<1.15 $\end{document}, CEP moves in the direction of lower temperature and larger quark chemical potential. However, for \begin{document}$ q>1.15 $\end{document}, CEP turns to move in the direction of lower temperature and lower quark chemical potential. In addition, we studied the moments of the net-baryon number distribution, that is, variance (\begin{document}$ \sigma^{2} $\end{document}), skewness (S), and kurtosis (κ). Our results are generally consistent with the latest experimental data reported, especially for \begin{document}$ \sqrt{S_{NN}}>19.6\ \mathrm{GeV} $\end{document}, when q is set to \begin{document}$ 1.07 $\end{document}.     

Z0 boson associated b-jet production in high-energy nuclear collisions

The production of vector boson tagged heavy quark jets potentially provides new tools to probe the jet quenching effect. In this paper, we present the first theoretical study on the angular correlations (\begin{document}$ \Delta\phi_{bZ} $\end{document}), transverse momentum imbalance (\begin{document}$ x_{bZ} $\end{document}), and nuclear modification factor (\begin{document}$ I_{AA} $\end{document}) of \begin{document}$ Z^0 $\end{document} boson tagged b-jets in heavy-ion collisions, which was performed using a Monte Carlo transport model. We find that the medium modification of the \begin{document}$ \Delta\phi_{bZ} $\end{document} for \begin{document}$ Z^0$\end{document} + b-jet has a weaker dependence on \begin{document}$ \Delta\phi_{bZ} $\end{document} than that for \begin{document}$ Z^0$\end{document} + jet, and the modification patterns are sensitive to the initial jet \begin{document}$ p_T $\end{document} distribution. Additionally, with the high purity of the quark jet in \begin{document}$ Z^0$\end{document} + (b-) jet production, we calculate the momentum imbalance \begin{document}$ x_{bZ} $\end{document} and the nuclear modification factor \begin{document}$ I_{AA} $\end{document} of \begin{document}$ Z^0$\end{document} + b-jet in Pb+Pb collisions. We observe a smaller \begin{document}$ \Delta \langle x_{jZ} \rangle $\end{document} and larger \begin{document}$ I_{AA} $\end{document} of \begin{document}$ Z^0$\end{document} + b-jet in Pb+Pb collisions relative to those of \begin{document}$ Z^0$\end{document} + jet, which may be an indication of the mass effect of jet quenching and can be tested in future measurements.     

Reaction 55Mn + 159Tb : preparation for the synthesis of new elements

The complete fusion reaction of \begin{document}$^{55}$\end{document}Mn + \begin{document}$^{159}$\end{document}Tb was studied on the gas-filled recoil separator SHANS2. Nineteen ER - α\begin{document}$_{1}$\end{document} - α\begin{document}$_{2}$\end{document} decay chains from \begin{document}$^{210}$\end{document}Th produced from the 4n evaporation channel were observed. The α-particle energy and half-life of \begin{document}$^{210}$\end{document}Th were determined as 7922(14) keV and 14(4) ms, respectively. In addition, the decay properties of \begin{document}$E_{\alpha}$\end{document} = 7788(14) keV and \begin{document}$T_{1/2}$\end{document} = 36\begin{document}$^{+15}_{-8}$\end{document} ms were obtained for \begin{document}$^{211}$\end{document}Th. The measured α decay properties of \begin{document}$^{210}$\end{document}Th and \begin{document}$^{211}$\end{document}Th were consistent with literature data. The cross sections were measured to be 0.59\begin{document}$^{+0.25}_{-0.23}$\end{document} nb and 0.19\begin{document}$^{+0.12}_{-0.09}$\end{document} nb for \begin{document}$^{210}$\end{document}Th and \begin{document}$^{211}$\end{document}Th, respectively. The equilibrium charge state of the recoiled nucleus \begin{document}$^{210}$\end{document}Th was determined experimentally. The new data were helpful for estimating the equilibrium charge states of elements 119 and 120, which could be produced via the \begin{document}$^{240}$\end{document}Pu(\begin{document}$^{55}$\end{document}Mn, 3n)\begin{document}$^{292}$\end{document}119 and \begin{document}$^{243}$\end{document}Am(\begin{document}$^{55}$\end{document}Mn, 3n)\begin{document}$^{295}$\end{document}120 reactions, respectively.     

Open charm mesons and charmonia in magnetized strange hadronic matter

We investigate the in-medium masses of open charm mesons (D(\begin{document}$ D^0 $\end{document}, \begin{document}$ D^+ $\end{document}), \begin{document}$ \bar{D} $\end{document}(\begin{document}$ \bar{D^0} $\end{document}, \begin{document}$ D^- $\end{document}), \begin{document}$ D_s $\end{document}(\begin{document}$ {D_{s}}^+ $\end{document}, \begin{document}$ {D_{s}}^- $\end{document})) and charmonium states (\begin{document}$ J/\psi $\end{document}, \begin{document}$ \psi(3686) $\end{document}, \begin{document}$ \psi(3770) $\end{document}, \begin{document}$ \chi_{c0} $\end{document}, \begin{document}$ \chi_{c2} $\end{document}) in strongly magnetized isospin asymmetric strange hadronic matter using a chiral effective model. In the presence of a magnetic field, the number and scalar densities of charged baryons have contributions from Landau energy levels. The mass modifications of open charm mesons result from their interactions with nucleons, hyperons, and the scalar fields (the non-strange field σ, strange field ζ, and isovector field δ) in the presence of a magnetic field. The mass modifications of the charmonium states result from the modification of gluon condensates in a medium simulated by the variation in the dilaton field (χ) in the chiral effective model. The effects of finite quark masses are also incorporated in the trace of the energy-momentum tensor in quantum chromodynamics to investigate the mass shifts of charmonium states. The in-medium masses of open charm mesons and charmonia are observed to decrease with an increase in baryon density. The charged \begin{document}$ D^+ $\end{document}, \begin{document}$ D^- $\end{document}, \begin{document}$ {D_{s}}^+ $\end{document}, and \begin{document}$ {D_{s}}^- $\end{document} mesons have additional positive mass shifts due to Landau quantization in the presence of a magnetic field. The effects of the strangeness fraction are observed to be more dominant for \begin{document}$ \bar{D} $\end{document} mesons compared with D mesons. The mass shifts of charmonia are observed to be larger in hyperonic media compared with nuclear media when the effect of the finite quark mass term is neglected. These medium mass modifications can have observable consequences on the production of the open charm mesons and charmonia in high-energy asymmetric heavy-ion collision experiments.     

Analysis of the interaction between the ? meson and nucleus

In this study, we systematically investigate the ? meson and nucleus interaction by analyzing and fitting the cross sections of \begin{document}$ \gamma N $\end{document}\begin{document}$ \rightarrow \phi $\end{document}N reactions near the threshold, where N represents the nucleus. Using the vector meson dominant model, the distribution of the ?-N scattering length is presented as a function of energy, and the results show that there is a slight increase in scattering length with increasing energy. Based on this, the average scattering length of a ?-proton is obtained as\begin{document}$ 0.10\pm0.01 $\end{document} fm by combining experimental data and theoretical models. Moreover, the average scattering length of the ?-deuteron interaction is derived to be \begin{document}$ 0.014\pm0.002 $\end{document} fm for the first time. Furthermore, the effect of the momentum transfer \begin{document}$|t_{{\rm min}}|$\end{document} on the ?-N scattering length at the threshold is discussed. The obtained results not only provide important theoretical information for a more comprehensive and accurate study of the ?-N scattering length, but also a basis for future experimental measurements of ? meson production.     

Renormalization of one-pion exchange in higher partial waves in chiral effective field theory for antinucleon-nucleon system

The renormalization of the iterated one-pion exchange (OPE) has been studied in chiral effective field theory (χEFT) for the antinucleon-nucleon (\begin{document}$ \overline{N} N $\end{document}) scattering in some partial waves (Phys. Rev. C 105, 054005 (2022)). In this paper, we go further for the other higher partial waves but with total angular momenta \begin{document}$ J\leq 3 $\end{document}. Contact interactions are represented by a complex spherical well in the coordinate space. Changing the radius of the spherical well means changing the cutoff. We check the cutoff dependence of the phase shifts, inelasticities, and mixing angles for the partial waves and show that contact interactions are needed at leading order in channels where the singular tensor potentials of OPE are attractive. The results are compared with the energy-dependent partial-wave analysis of \begin{document}$ \overline{N} N $\end{document} scattering data. Comparisons between our conclusions and applications of χEFT to the nucleon-nucleon system are also discussed.     

Color-flavor dependence of the Nambu-Jona-Lasinio model and QCD phase diagram

We study the dynamical chiral symmetry breaking/restoration for various numbers of light quarks flavors \begin{document}$ N_f $\end{document} and colors \begin{document}$ N_c $\end{document} using the Nambu-Jona-Lasinio (NJL) model of quarks in the Schwinger-Dyson equation framework, dressed with a color-flavor dependence of effective coupling. For fixed \begin{document}$ N_f = 2 $\end{document} and varying \begin{document}$ N_c $\end{document}, we observe that the dynamical chiral symmetry is broken when \begin{document}$ N_c $\end{document} exceeds its critical value \begin{document}$ N^{c}_{c}\approx2.2 $\end{document}. For a fixed \begin{document}$ N_c = 3 $\end{document} and varying \begin{document}$ N_f $\end{document}, we observe that the dynamical chiral symmetry is restored when \begin{document}$ N_f $\end{document} reaches its critical value \begin{document}$ N^{c}_{f}\approx8 $\end{document}. Strong interplay is observed between \begin{document}$ N_c $\end{document} and \begin{document}$ N_f $\end{document}, i.e., larger values of \begin{document}$ N_c $\end{document} tend to strengthen the dynamical generated quark mass and quark-antiquark condensate, while higher values of \begin{document}$ N_f $\end{document} suppress both parameters. We further sketch the quantum chromodynamics (QCD) phase diagram at a finite temperature T and quark chemical potential μ for various \begin{document}$ N_c $\end{document} and \begin{document}$ N_f $\end{document}. At finite T and μ, we observe that the critical number of colors \begin{document}$ N^{c}_c $\end{document} is enhanced, whereas the critical number of flavors \begin{document}$ N^{c}_f $\end{document} is suppressed as T and μ increase. Consequently, the critical temperature \begin{document}$ T_c $\end{document}, \begin{document}$ \mu_c $\end{document}, and co-ordinates of the critical endpoint \begin{document}$ (T^{E}_c,\mu^{E}_c) $\end{document} in the QCD phase diagram are enhanced as \begin{document}$ N_c $\end{document} increases and suppressed when \begin{document}$ N_f $\end{document} increases. Our findings agree with the lattice QCD and Schwinger-Dyson equations predictions.     

Same-sign tetralepton signature in type-Ⅱ seesaw at lepton colliders

The same-sign tetralepton signature via the mixing of neutral Higgs bosons and their cascade decays to charged Higgs bosons is a unique signal in the type-Ⅱ seesaw model with the mass spectrum M_A⁰≈M_H⁰>M_H⁺>M_H^±±.In this study,we investigate this signature at future lepton colliders,such as the ILC,CLIC,and MuC.Direct searches for doubly charged scalar H^±±at the LHC have excluded MHg+t<350(870) GeV in the H^±±+W^±W(±)(l^±±)decay mode.Therefore,we choose M_A⁰=400,600,1000,1500 GeV as our benchmark scenarios.Constrained by direct search,H^±±+W^±W(±)(l^±±)d=is the only viable decay mode for Mρ=400 GeV at the √s=1 TeV ILC.With an integrated luminosity L=8 ab^-1,the promising region,with approximately 150 signal events,corresponds to a narrow band in the range of 10^-4 GeV≤v△≤10^-2GeV.Meanwhile,for Mpo=600 GeV at the √s=1.5 TeV CLIC,approximately 10 signal events can be produced with L=2.5 ab^-1.For heavier triplet scalars M_A⁰■870 GeV,although the H^±± decay mode is allowed,the cascade decays are suppressed.A maximum event number~16 can be obtained at approximately v△~4×10⁴GeV and λ₁₄~0.26 for M_A⁰=1000 GeV with L=5 ab^-1 at the √s=3 TeV CLIC.Finally,we find that this signature is not promising for M_A⁰= 1500 GeV at the √s=6 TeV MuC.Based on the benchmark scenarios,we also study the observability of this signature.In the H^±±+W^±W(±)(l^±±)d mode,one can probe MρS 800(1160) GeV at future lepton colliders.     

Double-heavy tetraquarks with strangeness in the chiral quark model

Recently, some progress has been made in the experiments on double-heavy tetraquarks, such as \begin{document}$ T_{cc} $\end{document} reported by the LHCb Collaboration and \begin{document}$ X_{cc\bar{s}\bar{s}} $\end{document} reported by the Belle Collaboration. Coming on the heels of our previous work about \begin{document}$ T_{cc} $\end{document} and \begin{document}$ T_{bb} $\end{document}, we present a study on the bound and resonance states of their companions, \begin{document}$ QQ\bar{q}\bar{s} $\end{document} (\begin{document}$ Q=c,b; q=u, s $\end{document}) tetraquarks with strange flavor in the chiral quark model. Two pictures, meson-meson and diquark-antidiquark ones, and their couplings were considered in our calculations. Isospin violation was neglected herein. Our numerical analysis indicated that the states \begin{document}$ cc\bar{u}\bar{s} $\end{document} with \begin{document}$ \dfrac{1}{2}(1^+) $\end{document} and \begin{document}$ bb\bar{u}\bar{s} $\end{document} with \begin{document}$ \dfrac{1}{2}(1^+) $\end{document} are the most promising stable states against strong interactions. Besides, we found several resonance states for the double-heavy strange tetraquarks with the real scaling method.     

Analysis of Pcs(4338) and related pentaquark molecular states via QCD sum rules

In this study, we tentatively identify \begin{document}$ P_{cs}(4338) $\end{document} as the \begin{document}$ \bar{D}\Xi_c $\end{document}molecular state and distinguish the isospins of current operators to explore in detail the\begin{document}$ \bar{D}\Xi_c $\end{document}, \begin{document}$ \bar{D}\Lambda_c $\end{document}, \begin{document}$ \bar{D}_s\Xi_c $\end{document}, \begin{document}$ \bar{D}_s\Lambda_c $\end{document}, \begin{document}$ \bar{D}^*\Xi_c $\end{document}, \begin{document}$ \bar{D}^*\Lambda_c $\end{document}, \begin{document}$ \bar{D}^*_s\Xi_c $\end{document}, and \begin{document}$ \bar{D}^*_s\Lambda_c $\end{document} molecular states without strange, with strange, and with double strange in the framework of QCD sum rules. The present exploration favors identifying \begin{document}$ P_{cs}(4338) $\end{document} (\begin{document}$ P_{cs}(4459) $\end{document}) as the \begin{document}$ \bar{D}\Xi_c $\end{document} (\begin{document}$ \bar{D}^*\Xi_c $\end{document}) molecular state with the spin-parity \begin{document}$ J^P={\dfrac{1}{2}}^- $\end{document} (\begin{document}$ {\dfrac{3}{2}}^- $\end{document}) and isospin \begin{document}$ (I,I_3)=(0,0) $\end{document}, and the observation of their cousins with the isospin \begin{document}$ (I,I_3)=(1,0) $\end{document} in the \begin{document}$ J/\psi\Sigma^0/\eta_c\Sigma^0 $\end{document} invariant mass distributions would decipher their inner structures.     

Effects of Λ hyperons on the deformations of even–even nuclei

The deformations of multi-\begin{document}$ {\Lambda} $\end{document} hypernuclei corresponding to even–even core nuclei ranging from \begin{document}$ ^8 $\end{document}Be to \begin{document}$ ^{40} $\end{document}Ca with 2, 4, 6, and 8 hyperons are studied using the deformed Skyrme–Hartree–Fock approach. It is found that the deformations are reduced when adding 2 or 8 \begin{document}$ {\Lambda} $\end{document} hyperons, but enhanced when adding 4 or 6 \begin{document}$ {\Lambda} $\end{document} hyperons. These differences are attributed to the fact that \begin{document}$ {\Lambda} $\end{document} hyperons are filled gradually into the three deformed \begin{document}$ p $\end{document} orbits, of which the [110]1/2\begin{document}$ ^- $\end{document} orbit is prolately deformed and the degenerate [101]1/2\begin{document}$ ^- $\end{document} and [101]3/2\begin{document}$ ^- $\end{document} orbits are oblately deformed.