New behaviors of α-particle preformation factors near doubly magic 100Sn

The \begin{document}$ \alpha $\end{document}-particle preformation factors of nuclei above doubly magic nuclei \begin{document}$ ^{100} $\end{document}Sn and \begin{document}$ ^{208} $\end{document}Pb are investigated within the generalized liquid drop model. The results show that the \begin{document}$ \alpha $\end{document}-particle preformation factors of nuclei near self-conjugate doubly magic \begin{document}$ ^{100} $\end{document}Sn are significantly larger than those of analogous nuclei just above \begin{document}$ ^{208} $\end{document}Pb, and they will be enhanced as the nuclei move towards the \begin{document}$ N = Z $\end{document} line. The proton–neutron correlation energy \begin{document}$ E_{p-n} $\end{document} and two protons–two neutrons correlation energy \begin{document}$ E_{2p-2n} $\end{document} of nuclei near \begin{document}$ ^{100} $\end{document}Sn also exhibit a similar situation, indicating that the interactions between protons and neutrons occupying similar single-particle orbitals could enhance the \begin{document}$ \alpha $\end{document}-particle preformation factors and result in superallowed \begin{document}$ \alpha $\end{document} decay. This also provides evidence of the significant role of the proton–neutron interaction on \begin{document}$ \alpha $\end{document}-particle preformation. Also, the linear relationship between \begin{document}$ \alpha $\end{document}-particle preformation factors and the product of valence protons and valence neutrons for nuclei around \begin{document}$ ^{208} $\end{document}Pb is broken in the \begin{document}$ ^{100} $\end{document}Sn region because the \begin{document}$ \alpha $\end{document}-particle preformation factor is enhanced when a nucleus near \begin{document}$ ^{100} $\end{document}Sn moves towards the \begin{document}$ N = Z $\end{document} line. Furthermore, the calculated \begin{document}$ \alpha $\end{document} decay half-lives fit well with the experimental data, including the recent observed self-conjugate nuclei \begin{document}$ ^{104} $\end{document}Te and \begin{document}$ ^{108} $\end{document}Xe [Phys. Rev. Lett. 121, 182501 (2018)].     

Surface geometry and shadow of a Schwarzschild black hole with a halo

We studied the surface geometry and shadows of a Schwarzschild black hole with a halo containing quadrupolar and octopolar terms. It was found that the quadrupole term causes a Schwarzschild black hole to be prolate at the quadrupole strength \begin{document}$ {\cal{Q}}<0 $\end{document} and oblate at \begin{document}$ {\cal{Q}}>0 $\end{document}, and the octopole term causes to the shadow stretch upward at the octopolar strength ngth \begin{document}$ {\cal{O}}<0 $\end{document} and downward at \begin{document}$ {\cal{O}}>0 $\end{document}. The shadow of a Schwarzschild black hole with a halo stretches and squeezes along the horizontal direction at \begin{document}$ {\cal{Q}}<0 $\end{document} and \begin{document}$ {\cal{Q}}>0 $\end{document}, respectively. Meanwhile, the black hole shadow shifts upward at \begin{document}$ {\cal{O}}<0 $\end{document} and downward at \begin{document}$ {\cal{O}}>0 $\end{document}. We present the light rays that form the shadow boundary to explain the emergence of the extraordinary patterns of the black hole shadow with quadrupole and octopole terms. From the observable width W, height H, oblateness K, and distortion parameter \begin{document}$ \delta_{c} $\end{document} of the black hole shadow, we can determine the quadrupole and octopolar strengths of a Schwarzschild black hole with a halo. Our results show that the quadrupolar and octopolar terms yield a series of interesting patterns for the shadow of a Schwarzschild black hole with a halo.     

Annihilation diagram contribution to charmonium masses

In this work, we generate gauge configurations with \begin{document}$ N_f = 2 $\end{document} dynamical charm quarks on anisotropic lattices. The mass shift of \begin{document}$ 1S $\end{document} and \begin{document}$ 1P $\end{document} charmonia due to the charm quark annihilation effect can be investigated directly in a manner of unitary theory. The distillation method is adopted to treat the charm quark annihilation diagrams at a very precise level. For \begin{document}$ 1S $\end{document} charmonia, the charm quark annihilation effect barely changes the \begin{document}$ J/\psi $\end{document} mass, but lifts the \begin{document}$ \eta_c $\end{document} mass by approximately 3–4 MeV. For \begin{document}$ 1P $\end{document} charmonia, this effect results in positive mass shifts of approximately 1 MeV for \begin{document}$ \chi_{c1} $\end{document} and \begin{document}$ h_c $\end{document}, but decreases the \begin{document}$ \chi_{c2} $\end{document} mass by approximately 3 MeV. We did not obtain a reliable result for the mass shift of \begin{document}$ \chi_{c0} $\end{document}. In addition, we observed that the spin averaged mass of the spin-triplet \begin{document}$ 1P $\end{document} charmonia is in good agreement with \begin{document}$ h_c $\end{document}, as expected by the non-relativistic quark model and measured by experiments.     

The effect of hadronic scatterings on the measurement of vector meson spin alignments in heavy-ion collisions

Spin alignments of vector mesons and hyperons in relativistic heavy-ion collisions have been proposed as signals of global polarization.The STAR experiment first observed the ∧ polarization.Recently,the ALICE collaboration measured the transverse momentum {PT) and the collision centrality dependence of K*,and Φ spin alignments during Pb-Pb collisions at ~(1/2)sNN=2.76 TeV.A large signal is observed in the low pT region of mid-central collisions for K~*,while the signal is much smaller for Φ,and these have not been understood yet.Since vector mesons have different lifetimes and their decay products have different scattering cross sections,they suffer from different hadronic effects.In this paper,we study the effect of hadronic interactions on the spin alignment of K~*,Φ,and p mesons in relativistic heavy-ion collisions with a multi-phase transport model.We find that hadronic scatterings lead to a deviation of the observed spin alignment matrix element p00 away from the true value for p and K*mesons(with a bigger effect on p) while the effect is negligible for the Φ meson.The effect depends on the kinematic acceptance:the observed p00 value is lower than the true value when the pseudorapidity(η) coverage is small,while there is little effect when the η coverage is large.Hence,this study provides valuable information to understand the vector meson spin alignment signals observed during the experiments.     

Molecular picture for X_0(2900) and X_1(2900)

Inspired by the newly observed X_0(2900) and X_1(2900) states at LHCb,the K~*■ and K■ interactions are studied in the quasipotential Bethe-Salpeter equation approach combined with the one-bo son-exchange model.The bound and virtual states from the interactions are searched for as poles in the complex energy plane of scattering amplitude.A bound state with I(J~P)=0(0~+) and a virtual state with 0(1~-) are produced from the K~*■ interaction and K■ interaction,and can be related to the X_0(2900) and X_1(2900) observed at LHCb,respectively.A bound state with I(J~P)=0(1~+) and a virtual state with I(J~P)=0(2~+) are also predicted from the K~*■ interaction,with the same α value,to reproduce the X_(0,1)(2900),which can be searched for in future experiments.     

Mixing of X and Y states from QCD sum rules analysis

We study \begin{document}$ \bar{Q}Q\bar{q}q $\end{document} and \begin{document}$ \bar{Q}qQ\bar{q} $\end{document} states as mixed states in QCD sum rules. By calculating the two-point correlation functions of pure states of their corresponding currents, we review the mass and coupling constant predictions of \begin{document}$ J^{PC} = 1^{++} $\end{document}, \begin{document}$1^{--}$\end{document}, and \begin{document}$ 1^{-+} $\end{document} states. By calculating the two-point mixed correlation functions of \begin{document}$ \bar{Q}Q\bar{q}q $\end{document} and \begin{document}$ \bar{Q}qQ\bar{q} $\end{document} currents, we estimate the mass and coupling constants of the corresponding "physical state" that couples to both \begin{document}$ \bar{Q}Q\bar{q}q $\end{document} and \begin{document}$ \bar{Q}qQ\bar{q} $\end{document} currents. Our results suggest that for \begin{document}$ 1^{++} $\end{document} states, the \begin{document}$ \bar{Q}Q\bar{q}q $\end{document} and \begin{document}$ \bar{Q}qQ\bar{q} $\end{document} components are more likely to mix, while for \begin{document}$ 1^{--} $\end{document} and \begin{document}$ 1^{-+} $\end{document} states, there is less mixing between \begin{document}$ \bar{Q}Q\bar{q}q $\end{document} and \begin{document}$ \bar{Q}qQ\bar{q} $\end{document}. Our results suggest the Y series of states have more complicated components.     

Radial excited heavy mesons

In this study, the first radial excited heavy pseudoscalar and vector mesons (\begin{document}$\eta_c(2S)$\end{document}, \begin{document}$\psi(2S)$\end{document}, \begin{document}$B_c(2S)$\end{document}, \begin{document}$B^*_c(2S)$\end{document}, \begin{document}$\eta_b(2S)$\end{document}, and \begin{document}$\varUpsilon(2S)$\end{document}) are investigated using the Dyson-Schwinger equation and Bethe-Salpeter equation approach. It is shown that the effective interactions of the radial excited states are harder than those of the ground states. With the interaction well determined by fitting the masses and leptonic decay constants of \begin{document}$\psi(2S)$\end{document} and \begin{document}$\varUpsilon(2S)$\end{document}, the first radial excited heavy mesons could be quantitatively described in the rainbow ladder approximation. The masses and leptonic decay constants of \begin{document}$\eta_c(2S)$\end{document}, \begin{document}$B_c(2S)$\end{document}, \begin{document}$B^*_c(2S)$\end{document}, and \begin{document}$\eta_b(2S)$\end{document} are predicted.     

Analysis of hidden-charm pentaquark molecular states with and without strangeness via the QCD sum rules

In this study, we investigate the \begin{document}$\bar{D}\Sigma_c$\end{document}, \begin{document}$\bar{D}\Xi^\prime_c$\end{document}, \begin{document}$\bar{D}\Sigma_c^*$\end{document}, \begin{document}$\bar{D}\Xi_c^*$\end{document}, \begin{document}$\bar{D}^{*}\Sigma_c$\end{document}, \begin{document}$\bar{D}^{*}\Xi^\prime_c$\end{document}, \begin{document}$\bar{D}^{*}\Sigma_c^*$\end{document}, and \begin{document}$\bar{D}^{*}\Xi_c^*$\end{document} pentaquark molecular states with and without strangeness via the QCD sum rules in detail, focusing on the light flavor, \begin{document}$SU(3)$\end{document} , breaking effects, and make predictions for new pentaquark molecular states besides assigning \begin{document}$P_c(4312)$\end{document}, \begin{document}$P_c(4380)$\end{document}, \begin{document}$P_c(4440)$\end{document}, \begin{document}$P_c(4457)$\end{document} , and \begin{document}$P_{cs}(4459)$\end{document} self-consistently. In the future, we can search for these pentaquark molecular states in the decay of \begin{document}$\Lambda_b^0$\end{document}, \begin{document}$\Xi_b^0$\end{document} , and \begin{document}$\Xi_b^-$\end{document} . Furthermore, we discuss high-dimensional vacuum condensates in detail.     

Study of C parity violating and strangeness changing J/ψ→PP weak decays

Although J/ψ weak decays are rare,they are possible within the standard model of elementary particles.Inspired by the potential prospects of the future intensity frontier,the C parity violating J/ψ→πη~((')),ηη' decays and the strangeness changing J/ψ→πK,Kη~((')) decays are studied via the perturbative QCD approach.It is determined that the J/ψ→ηη' decays have relatively large branching ratios,approximately on the order of 10~(-11),which might be within the measurement capability and sensitivity of the future STCF experiment.     

A non-renormalizable B-L model with Q4 × Z4 × Z2 flavor symmetry for cobimaximal neutrino mixing

We construct a non-renormalizable gauge \begin{document}$ B-L $\end{document} model based on \begin{document}$ Q_4\times Z_4\times Z_2 $\end{document} symmetry that successfully explains the cobimaximal lepton mixing scheme. Small active neutrino masses and both neutrino mass hierarchies are produced via the type-I seesaw mechanism at the tree-level. The model is predictive; hence, it reproduces the cobimaximal lepton mixing scheme, and the reactor neutrino mixing angle \begin{document}$ \theta_{13} $\end{document} and the solar neutrino mixing angle \begin{document}$ \theta_{12} $\end{document} can obtain best-fit values from recent experimental data. Our model also predicts the effective neutrino mass parameters of \begin{document}$ m_{\beta }\in (8.80, 9.05)\, \mathrm{meV} $\end{document} and \begin{document}$ \langle m_{ee}\rangle \in (3.65, 3.95)\, \mathrm{meV} $\end{document} for normal ordering (NO) and \begin{document}$ m_{\beta }\in (49.16, 49.21)\, \mathrm{meV} $\end{document} and \begin{document}$ \langle m_{ee}\rangle \in (48.59, 48.67)\, \mathrm{meV} $\end{document} for inverted ordering (IO), which are highly consistent with recent experimental constraints.     

Impact of lepton p_T threshold on charge asymmetry predictions for inclusive W boson production in pp collisions at 13 TeV

This paper presents the impact of the lepton transverse momentum p_T~l threshold on the W boson charge asymmetry predictions in perturbative QCD for the inclusive W~++X→l~±v+X production in proton-proton(pp)collisions.The predictions are obtained at various low-p_T~l thresholds p_T~l 20,25,30,and 40 GeV in a fiducial region encompassing both the central and forward detector acceptances in terms of the lepton pseudorapidity0 ≤η_l≤4.5.The predicted distributions for the lepton charge asymmetry,which is defined by η_l(A_(η_l)),at the nextto-next-to-leading order(NNLO) accuracy are compared with the CMS and LHCb data at 8 TeV center-of-mass collision energy.The 8 TeV predictions reproduce the data fairly well within the quoted uncertainties.The predictions from the CT14 parton distribution function(PDF) model are in a slightly better agreement with the data over the other PDF sets that are tested.The 13 TeV predictions using various p_T~l thresholds are reported for A_(η_l) and the charge asymmetries that are defined in terms of the differential cross sections in bins of the W boson rapidity yw(A_(y_w)) and transverse momentum p_T~W(A_(p_T~W)).The NNLO predictions for the A_(η_l),A_(y_w).and A_(p_T~W) distributions are assessed to be in close correlation with the p_T~l value.The A_(η_l) and A_(y_w) distributions are particularly shown to be more correlated at a higher p_T~l threshold.The A_(p_T~W) distributions are also reported from the merged predictions with improved accuracy by the inclusion of the next-to-next-to-next-to-leading logarithm(N'LL) corrections,i.e.,at NNLO+N~3 LL.The predicted distributions from various p_T~l thresholds represent a finer probe in terms of the capability to provide more constraints on the ratio of u and d quark distribution functions in the parton momentum fraction range 10~(-4) x1.     

Discovery potentials of double-charm tetraquarks

In this study, we investigate the discovery potential of double-charm tetraquarks \begin{document}$ T^{\{cc\}}_{[\bar{q}\bar{q}']} $\end{document}. We find that their production cross sections at the LHCb with \begin{document}$ \sqrt{s} = 13 $\end{document} TeV reach \begin{document}$ \mathcal{O}(10^4) $\end{document} pb, which indicates that the LHCb has collected \begin{document}$ \mathcal{O}(10^8) $\end{document} such particles. Through the decay channels of \begin{document}$ T^{\{cc\}}_{[\bar{u}\bar{d}]}\to D^{+}K^{-}\pi^{+} $\end{document} or \begin{document}$ D^0D^+\gamma $\end{document} (if stable) or \begin{document}$ T^{\{cc\}}_{[\bar{u}\bar{d}]}\to D^0D^{*+}\to D^0D^0\pi^+ $\end{document} (if unstable), it is highly expected that they get discovered at the LHCb in the near future. We also discuss the productions and decays of the double-charm tetraquarks at future Tera-\begin{document}$ Z $\end{document} factories.     

Microscopic study of higher-order deformation effects on the ground states of superheavy nuclei around 270Hs

We investigate the effects of higher-order deformations \begin{document}$\beta_\lambda$\end{document} (\begin{document}$\lambda=4,6,8,$\end{document} and 10) on the ground state properties of superheavy nuclei (SHN) near the doubly magic deformed nucleus \begin{document}$^{270}{\rm{Hs}}$\end{document} using the multidimensionally-constrained relativistic mean-field (MDC-RMF) model with five effective interactions: PC-PK1, PK1, NL3^*, DD-ME2, and PKDD. The doubly magic properties of \begin{document}$^{270}{\rm{Hs}}$\end{document} include large energy gaps at \begin{document}$N=162$\end{document} and \begin{document}$Z=108$\end{document} in the single-particle spectra. By investigating the binding energies and single-particle levels of \begin{document}$^{270}{\rm{Hs}}$\end{document} in the multidimensional deformation space, we find that, among these higher-order deformations, the deformation \begin{document}$\beta_6$\end{document} has the greatest impact on the binding energy and influences the shell gaps considerably. Similar conclusions hold for other SHN near \begin{document}$^{270}{\rm{Hs}}$\end{document}. Our calculations demonstrate that the deformation \begin{document}$\beta_6$\end{document} must be considered when studying SHN using MDC-RMF.     

Interpretation of XENON1T excess with MeV boosted dark matter

The XENON1T excess of keV electron recoil events may be induced by the scattering of electrons and long-lived particles with an MeV mass and high speed. We consider a tangible model composed of two scalar MeV dark matter (DM) particles, \begin{document}$ S_A $\end{document} and \begin{document}$ S_B $\end{document}, to interpret the XENON1T keV excess via boosted \begin{document}$ S_B $\end{document}. A small mass splitting \begin{document}$ m_{S_A}-m_{S_B}>0 $\end{document} is introduced, and the boosted \begin{document}$ S_B $\end{document} can be produced using the dark annihilation process of \begin{document}$ S_A S_A^\dagger \to \phi \to S_B S_B^\dagger $\end{document} via a resonant scalar ?. \begin{document}$ S_B- $\end{document}electron scattering is intermediated by a vector boson X. Although the constraints from Big Bang nucleosynthesis, cosmic microwave background (CMB), and low-energy experiments set the \begin{document}$ X- $\end{document}mediated \begin{document}$ S_B- $\end{document}electron scattering cross section to be \begin{document}$ \lesssim 10^{-35} \mathrm{cm}^2 $\end{document}, the MeV scale DM with a resonance enhanced dark annihilation today can still provide sufficient boosted \begin{document}$ S_B $\end{document} and induce the XENON1T keV excess. The relic density of \begin{document}$ S_B $\end{document} is significantly reduced by the s-wave process \begin{document}$ S_B S_B^\dagger \to X X $\end{document}, which is permitted by the constraints from CMB and 21-cm absorption. A very small relic fraction of \begin{document}$ S_B $\end{document} is compatible with the stringent bounds on un-boosted \begin{document}$ S_B $\end{document}-electron scattering in DM direct detection, and the \begin{document}$ S_A $\end{document}-electron scattering is also allowed.     

Toward discovering low-lying P-wave excited Σc baryon states

In this study, by combining the equal spacing rule with recent observations of \begin{document}$ \Omega_c(X) $\end{document} and \begin{document}$ \Xi_c(X) $\end{document} baryons, we predict the spectrum of the low-lying \begin{document}$ \lambda $\end{document}-mode \begin{document}$ 1P $\end{document}-wave excited \begin{document}$ \Sigma_c $\end{document} states. Furthermore, their strong decay properties are predicted using the chiral quark model and the nature of \begin{document}$ \Sigma_c(2800) $\end{document} is investigated by analyzing the \begin{document}$ \Lambda_c\pi $\end{document} invariant mass spectrum. The \begin{document}$ \Sigma_c(2800) $\end{document} structure observed in the \begin{document}$ \Lambda_c \pi $\end{document} mass spectrum was found to potentially arise from two overlapping \begin{document}$ P $\end{document}-wave \begin{document}$ \Sigma_c $\end{document} resonances, \begin{document}$ \Sigma_c(2813)3/2^- $\end{document} and \begin{document}$ \Sigma_c(2840)5/2^- $\end{document}. These resonances have similar decay widths of \begin{document}$ \Gamma\sim 40 $\end{document} MeV and predominantly decay into the \begin{document}$ \Lambda_c \pi $\end{document} channel. The \begin{document}$ \Sigma_c(2755)1/2^- $\end{document} state is likely to be a very narrow state with a width of \begin{document}$ \Gamma\sim 15 $\end{document} MeV, with its decays almost saturated by the \begin{document}$ \Lambda_c \pi $\end{document} channel. Additionally, evidence of the \begin{document}$\Sigma_c(2755) {1}/{2}^-$\end{document} resonance as a very narrow peak may be seen in the \begin{document}$ \Lambda_c\pi $\end{document} invariant mass spectrum. The other two \begin{document}$ P $\end{document}-wave states, \begin{document}$\Sigma_c(2746) {1}/{2}^-$\end{document} and \begin{document}$\Sigma_c(2796) {3}/{2}^-$\end{document}, are relatively narrow states with similar widths of \begin{document}$ \Gamma\sim 30 $\end{document} MeV and predominantly decay into \begin{document}$ \Sigma_c\pi $\end{document} and \begin{document}$ \Sigma^{*}_c\pi $\end{document}, respectively. This study can provide useful references for discovering these low-lying \begin{document}$ P $\end{document}-wave states in forthcoming experiments.     

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.     

Phase structures of neutral dense quark matter and applicationto strange stars

In the contact interaction model,the quark propagator has only one solution,namely,the chiral symmetry breaking solution,at vanishing temperature and density in the case of physical quark mass.We generalize the condensate feedback onto the coupling strength from the 2 flavor case to the 2+1 flavor case,and find the Wigner solution appears in some regions,which enables us to tackle chiral phase transition as two-phase coexistences.At finite chemical potential,we analyze the chiral phase transition in the conditions of electric charge neutrality andβequilibrium.The four chemical potentials,μ_u,μ_d,μ_s and He,are constrained by three conditions,so that one inde-pendent variable remains:we choose the average quark chemical potential as the free variable.All quark masses and number densities suffer discontinuities at the phase transition point.The strange quarks appear after the phase trans-ition since the system needg more energy to produce a d.-quark than an s-quark.Taking the EOS as an input,the TOV equations are solved numerically,and we show that the mass--radius relation is sensitive to the EOS.The max-imum mass of strange quark stars is not susceptible to the parameter Aq we introduced.     

Dark matter,Z′, and vector-like quark at the LHC and b→sμμ anomaly

Combining the b→sμ~+μ~-anomaly and dark matter observables,we study the capability of the LHC to test dark matter,Z',and a vector-like quark.We focus on a local U(1)_(L_μ-L_τ) model with a vector-like SU(2)_L doublet quark Q and a complex singlet scalar whose lightest component X_I is a candidate of dark matter.After imposing relevant constraints,we find that the b→sμ~+μ~-anomaly and the relic abundance of dark matter favor m_(X_I) 350 GeV and m_(Z') 450 GeV for m_Q 2 TeV and m_(X_R) 2 TeV(the heavy partner of m_(X_I)).Current searches for jets and missing transverse momentum at the LHC sizably reduce the mass ranges of the vector-like quark,and m_Q is required to be larger than 1.7 TeV.Finally,we discuss the possibility of probing these new particles at the high luminosity LHC via the QCD process pp→DD followed byD→s(b)X_I,D→s(b)Z'X_I,and then Z'→μ~+μ~-.Taking a benchmark point of m_Q=1.93 TeV,m_(Z')=170 GeV,and m_(X_I)=145 GeV,we perform a detailed Monte Carlo simulation and find that this benchmark point can be accessed at the 14 TeV LHC with an integrated luminosity of 3000 fb~(-1).     

Bayesian inference on isospin splitting of nucleon effective mass from giant resonances in ~(208)Pb

From a Bayesian analysis of the electric dipole polarizability,the constrained energy of isovector giant dipole resonance,the peak energy of isocalar giant quadrupole resonance,and the constrained energy of isocalar giant monopole resonance in ~(208)Pb,we extract the iso scalar and isovector effective masses in nuclear matter at saturation density p_0 as m_(s,0)~*/m=0.87_(-0.04)~(+0.04) and m_(v,0)~*/m=0.78_(-0.05)~(+0.06),respectively,at 90% confidence level.The constraints obtained on m_(s,0)~* and m_(v,0)~* lead to a positive iso spin splitting of nucleon effective mass in asymmetric nuclear matter of iso spin asymmetry δ at p_0 as m_(n-p)~*/m=(0.20_(-0.14)~(+0.15))δ.In addition,the symmetry energy at the subsaturation density p~*=0.05 fm~(-3) is determined to be E_(sym)(p~*)=16.7±1.3 MeV at 90% confidence level.