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<jats:title>Abstract</jats:title> <jats:p>It is widely accepted nowadays that gluons, while massless at the level of the fundamental QCD Lagrangian, acquire an effective mass through the non-Abelian implementation of the classic Schwinger mechanism. The key dynamical ingredient that triggers the onset of this mechanism is the formation of composite massless poles inside the fundamental vertices of the theory. These poles enter in the evolution equation of the gluon propagator, and affect nontrivially the way the Slavnov-Taylor identities of the vertices are resolved, inducing a smoking-gun displacement in the corresponding Ward identities. In this article we present a comprehensive review of the pivotal concepts associated with this dynamical scenario, emphasizing the synergy between functional methods and lattice simulations, and highlighting recent advances that corroborate the action of the Schwinger mechanism in QCD. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Article funded by SCOAP3 and published under licence by Chinese Physical Society and the Institute of High Energy Physics of the Chinese Academy of Science and the Institute of Modern Physics of the Chinese Academy of Sciences and IOP Publishing Ltd.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>From December 2019 to June 2021, the BESIII experiment collected about 5.85 fb<jats:sup>−1</jats:sup> of data at center-of-mass energies between 4.61 GeV and 4.95 GeV. This is the highest collision energy BEPCII has reached so far. The accumulated e<jats:sup>+</jats:sup>e<jats:sup>−</jats:sup> annihilation data samples are useful for studying charmonium(-like) states and charmed-hadron decays. By adopting a novel method of analyzing the production of Λ<jats:sub>c</jats:sub> <jats:sup>+</jats:sup> Λ<jats:sub>c</jats:sub> <jats:sup>−</jats:sup> pairs in e<jats:sup>+</jats:sup>e<jats:sup>−</jats:sup> annihilation, the center-of-mass energies are measured with a precision of 0.6 MeV. Integrated luminosities are measured with a precision of better than 1% by analyzing the events of large-angle Bhabha scattering. These measurements provide important inputs to the analyses based on these data samples. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Article funded by SCOAP3 and published under licence by Chinese Physical Society and the Institute of High Energy Physics of the Chinese Academy of Science and the Institute of Modern Physics of the Chinese Academy of Sciences and IOP Publishing Ltd.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Recent advances in nuclear theory combined with new astrophysical observations have led to the need for specific theoretical models that actually apply to phenomena on dense-matter physics. At the same time, quantum chromodynamics (QCD) predicts the existence of non-nucleonic degrees of freedom at high densities in neutron-star matter, such as quark matter. Within a confining quark matter model, which consists of homogeneous, neutral 3-flavor interacting quark matter with $\mathcal{O}(m_s^4)$ corrections, we study the structure of compact stars made of a charged perfect fluid in the context of $f(R,T)$ gravity. The system of differential equations that describe the structure of charged compact stars have been derived and solved numerically for a gravity model with $f(R,T)= R+ 2\beta T$. For simplicity, we assume that the charge density is proportional to the energy density, namely, $\rho_{\rm ch} = \alpha \rho$. It is demonstrated that matter-geometry coupling constant $\beta$ and the charge parameter $\alpha$ affect the total gravitational mass and the radius of the star.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Neutron-induced nuclear recoil background is critical to the dark matter searches in the PandaX-4T liquid xenon experiment. This paper studies the feature of neutron background in liquid xenon and evaluates their contribution in the single scattering nuclear recoil events through three methods. The first method is fully Monte Carlo simulation based. The last two are data-driven methods that also use the multiple scattering signals and high energy signals in the data, respevtively. In the PandaX-4T commissioning data with an exposure of 0.63 tonne-year, all these methods give a consistent result that there are 1.15 $\pm$ 0.57 neutron-induced background in dark matter signal region within an approximated nuclear recoil energy window between 5 and 100 keV. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Article funded by SCOAP3 and published under licence by Chinese Physical Society and the Institute of High Energy Physics of the Chinese Academy of Science and the Institute of Modern Physics of the Chinese Academy of Sciences and IOP Publishing Ltd.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The recently proposed <jats:inline-formula> <jats:tex-math><?CDATA $ N^*(890) $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_46_8_081001_M2.jpg" xlink:type="simple" /> </jats:inline-formula> <jats:inline-formula> <jats:tex-math><?CDATA $ 1/2^- $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_46_8_081001_M3.jpg" xlink:type="simple" /> </jats:inline-formula> baryon is studied in a flavor <jats:inline-formula> <jats:tex-math><?CDATA $ S U(3) $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_46_8_081001_M4.jpg" xlink:type="simple" /> </jats:inline-formula> scheme with <jats:italic>K-</jats:italic>matrix unitarization, by fitting to low-energy cross section and phase shift data. It is found that <jats:inline-formula> <jats:tex-math><?CDATA $ N^*(890) $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_46_8_081001_M5.jpg" xlink:type="simple" /> </jats:inline-formula> co-exists with low-lying poles in other channels, which have been extensively discussed in the literature, though they belong to different octets in the <jats:inline-formula> <jats:tex-math><?CDATA $ S U(3) $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_46_8_081001_M6.jpg" xlink:type="simple" /> </jats:inline-formula> limit. Hence, the existence of <jats:inline-formula> <jats:tex-math><?CDATA $ N^*(890) $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_46_8_081001_M7.jpg" xlink:type="simple" /> </jats:inline-formula> is further verified. </jats:p>

<jats:title>Abstract</jats:title> <jats:p>Analytical formulae for the phase space factors and three-momenta of three- and four-body final states are derived for all sets of independent kinematic variables containing invariant mass variables. These formulae will help experimental physicists to perform data analysis. As an example, we show how to use these formulae to distinguish the different mechanisms of the <jats:inline-formula> <jats:tex-math><?CDATA $ e+p\to e+J/\psi+ p $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_46_8_083101_M1.jpg" xlink:type="simple" /> </jats:inline-formula> process when searching the signals of <jats:inline-formula> <jats:tex-math><?CDATA $ P_c $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_46_8_083101_M2.jpg" xlink:type="simple" /> </jats:inline-formula> states in the energy region of the Electron–Ion collider at China (EicC). </jats:p>

<jats:title>Abstract</jats:title> <jats:p>We consider a simple scalar dark matter model within the frame of gauged <jats:inline-formula> <jats:tex-math><?CDATA $ L_{\mu}-L_{\tau} $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_46_8_083102_M1.jpg" xlink:type="simple" /> </jats:inline-formula> symmetry. A new gauge boson <jats:inline-formula> <jats:tex-math><?CDATA $ Z' $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_46_8_083102_M2.jpg" xlink:type="simple" /> </jats:inline-formula>, as well as two scalar fields <jats:italic>S</jats:italic> and Φ, are introduced to the Standard Model (SM), where <jats:italic>S</jats:italic> and Φ are SM singlets but both carry <jats:inline-formula> <jats:tex-math><?CDATA $U(1)_{L_{\mu}-L_{\tau}} $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_46_8_083102_Z-20220506170050.jpg" xlink:type="simple" /> </jats:inline-formula> charge. The real component and imaginary component of <jats:italic>S</jats:italic> can acquire different masses after spontaneously breaking symmetry, and the lighter one can play the role of dark matter, which is stabilized by an extra <jats:inline-formula> <jats:tex-math><?CDATA $ Z_2 $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_46_8_083102_M4.jpg" xlink:type="simple" /> </jats:inline-formula> symmetry. We consider the possibility of light dark matter as well as the co-annihilation case in our model and present the current <jats:inline-formula> <jats:tex-math><?CDATA $ (g-2)_{\mu} $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_46_8_083102_M5.jpg" xlink:type="simple" /> </jats:inline-formula> anomaly, Higgs invisible decay, dark matter relic density, and direct detection constraints on the parameter space. Direct detection gives the most stringent restriction on the model, and we found that although most of the parameter space is excluded, a mass region of a few GeV is still allowed where the co-annihilation process is also permitted in the model. </jats:p>

<jats:title>Abstract</jats:title> <jats:p>Considering the <jats:italic>B</jats:italic> mesonic wave function <jats:inline-formula> <jats:tex-math><?CDATA $ {\phi}_{B2} $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_46_8_083103_M1.jpg" xlink:type="simple" /> </jats:inline-formula>, <jats:inline-formula> <jats:tex-math><?CDATA $ B {\to} PV $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_46_8_083103_M2.jpg" xlink:type="simple" /> </jats:inline-formula> decays are restudied in the leading order for three scenarios using the perturbative QCD approach within the standard model, where <jats:inline-formula> <jats:tex-math><?CDATA $ P = {\pi} $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_46_8_083103_M3.jpg" xlink:type="simple" /> </jats:inline-formula> and <jats:italic>K</jats:italic>, and <jats:italic>V</jats:italic> denotes the ground <jats:inline-formula> <jats:tex-math><?CDATA $S U(3)$?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_46_8_083103_M4.jpg" xlink:type="simple" /> </jats:inline-formula> vector mesons. It is found that contributions from <jats:inline-formula> <jats:tex-math><?CDATA $ {\phi}_{B2} $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_46_8_083103_M5.jpg" xlink:type="simple" /> </jats:inline-formula> can enhance most branching ratios and are helpful for improving the overall consistency of branching ratios between the updated calculations and available data, although there are still several discrepancies between the experimental and theoretical results. </jats:p>

<jats:title>Abstract</jats:title> <jats:p>A new approach for tree-level amplitudes with multiple fermion lines is presented. It primarily focuses on the simplification of fermion lines. By calculating two vectors recursively without any matrix multiplications, the result of a fermion line is reduced to a very compact form depending only on the two vectors. Comparisons with other packages are presented, and the results show that our package FDC provides a very good performance in the processes of multiple fermion lines with this new approach and some other improvements. A further comparison with WHIZARD shows that this new approach has a competitive efficiency in computing pure amplitude squares without phase space integration.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>In this paper, we present some results on the behavior of the total cross section and <jats:italic>ρ</jats:italic>-parameter at asymptotic energies in proton–proton ( <jats:inline-formula> <jats:tex-math><?CDATA $ pp $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_46_8_083105_M3.jpg" xlink:type="simple" /> </jats:inline-formula>) and antiproton–proton ( <jats:inline-formula> <jats:tex-math><?CDATA $ \bar{p}p $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_46_8_083105_M4.jpg" xlink:type="simple" /> </jats:inline-formula>) collisions. Hence, we consider three of the main theoretical results in high energy physics: the crossing property, derivative dispersion relation, and optical theorem. The use of such machinery facilitates the derivation of analytic formulas for a wide set of the measured global scattering parameters and some important relations between them. The suggested parameterizations approximate the energy dependence for the total cross section and <jats:italic>ρ</jats:italic>-parameter for <jats:inline-formula> <jats:tex-math><?CDATA $ pp $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_46_8_083105_M5.jpg" xlink:type="simple" /> </jats:inline-formula> and <jats:inline-formula> <jats:tex-math><?CDATA $ \bar{p}p $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_46_8_083105_M6.jpg" xlink:type="simple" /> </jats:inline-formula> with a statistically acceptable quality in the multi-TeV region. Additionally, the qualitative description is obtained for important interrelations, namely difference, sum, and ratio of the antiparticle–particle and particle–particle total cross sections. Despite the reduced number of experimental data for the total cross section and <jats:italic>ρ</jats:italic>-parameter at the TeV-scale, which complicates any prediction for the beginning of the asymptotic domain, the fitting procedures indicates that asymptotia occur in the energy range 25.5–130 TeV. Moreover, in the asymptotic regime, we obtain <jats:inline-formula> <jats:tex-math><?CDATA $ \alpha_{\mathbb{P}}=1 $?></jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpc_46_8_083105_M7.jpg" xlink:type="simple" /> </jats:inline-formula>. A detailed quantitative study of the energy behavior of the measured scattering parameters and their combinations in the ultra–high energy domain indicates that the scenario with the generalized formulation of the Pomeranchuk theorem is more favorable with respect to the original formulation of this theorem. </jats:p>