Design of hadronic calorimeter for DarkSHINE experiment

The sensitivity of the dark photon search through invisible decay final states in low-background experiments relies sig-nificantly on the neutron and muon veto efficiencies,which depend on the amount of material used and the design of the detector geometry.This paper presents the optimized design of the hadronic calorimeter(HCAL)used in the DarkSHINE experiment,which is studied using a GEANT4-based simulation framework.The geometry is optimized by comparing a traditional design with uniform absorbers to one that uses different thicknesses at different locations on the detector,which enhances the efficiency of vetoing low-energy neutrons at the sub-GeV level.The overall size and total amount of material used in the HCAL are optimized to be lower,owing to the load and budget requirements,whereas the overall performance is studied to satisfy the physical objectives.

Influence of Hyperon-Hyperon Interaction on Properties of Hadronic Star

The influences of hyperon-hyperon interaction on the overall properties of hadronic star are investigated in the framework of relativistic mean field （RMF） theory. For certain hyperon coupling, the weaker hyperon-hyperon interaction can lead to the heavier hadronic star, which accords with the observation of heavy neutron star in X-ray binaries. We find that the threshold densities of the hyperons with larger masses are brought to a lower values with the increase of the hyperon-hyperon interaction. The possibility of the existence of hyperon star is checked with the consideration of hyperon-hyperon interaction.

1-19 Role of N(2120) in K(1520) Photon and Hadronic Productions

The baryon spectrum and the baryon couplings are two of the most important issues in hadronic physics andthey are attracting much attention. Both on the experimental and theoretical sides, the nucleon excited states below2.0 GeV have been extensively studied[1]. However, the current information for the properties of states around orabove 2.0 GeV is scarce. On the other hand, in this energy region, many theoretical approaches have predictedmissing N states, which have not been so far observed. Hence, the study of the possible role played by the 2.0GeV region nucleon resonances in the available accurate data is timely and could shed light into the complicateddynamics that governs the high excited nucleon spectrum.

Probing Nuclei with High-Energy Hadronic Probes at Inverse Kinematics

Proton knockout reactions are a widely used tool to study nuclear ground-state distributions. While the interpretation of traditional experiments in direct kinematics has to account for initial and final state interactions, experiments in inverse kinematics can overcome such limitations. We discuss results of an experiment at the BM@N setup at JINR using a 12C beam at 48 GeV/c to study quasi-elastic scattering reactions, single proton distributions, and short-range correlated nucleon-nucleon pairs. The inverse kinematics allows for the direct measurement of the nucleon-nucleon pair center-of-mass motion and provides first experimental evidence for scale separation of such pairs. Based on these results, we will in the future study neutron-rich nuclei in inverse kinematics in the context of short-range correlations and neutron stars.

Quark Transport Properties in the Region of Coexistence of Both Hadronic and QGP Phases

The physical picture of coexistence of both hadronic and QGP phases is given by Friedberg and T.D. Lee's nontopology soliton model. The transport properties of quark in color space and spin space in a system of two-phase coexistence are investigated from both quantum and classical theories.

IMPROVED CALCULATION OF HADRONIC VACUUM POLARIZATION CORRECTIONS TO PHOTON PROPAGATOR

The hadronic vacuum polarization correction to the photon propagator is found by using the Dubnicka-Meshcheryakov parametrization of the pion form factor and new experimental data on the e^(+)e^(-)→hadrons anniKilation cross section.

Hadronic Transport Effects on Elliptic Flow

Elliptic flow v2 is considered as a probe to study partonic collectivity,and the measurement v2/εcan be used to describe the hydro behavior of the colliding system.We study the the effect of the hadronic process on the momentum anisotropy parameter v2 in a multiphase transport model.It is found that hadronic rescattering will depress the v2 signal built up at the partonic phase.A similar mass hierarchy is observed in the model as in the experiment at RHIC.We find that different particle species will approach the same ideal hydro limit if the hadronic process is excluded.

Calculation of a Three-Jet Cross Section via the e^(+)e^(−)→Hadronic Rindler Horizon→qqg Process

The cross section for three-jet events via the e^(+)e^(−)→hadronic Rindler horizon→qqg process is compared to experimental data from the OPAL collaboration.It is found that the model is consistent with the QCD experiments.

THE ROLE OF PARTON HARD SCATTERING IN HADRONIC INTERACTIONS

A soft-hard two-component approach to the description of high energy hadronic interactions is proposed.It shows the important role of parton hard scattering in explanation of the chief characteristics of high energy hadronic interactions.

Probing the Incompressibility of Dense Hadronic Matter near the QCD Phase Transition in Relativistic Heavy-ion Collisions

Based on the extended hadronic transport model,we investigate the incompressibility of dense hadronic matter formed in relativistic Au+Au heavy-ion collisions at√SNN=3 GeV.By comparing various experimental observ-ables,such as proton directed ow,production yields of strange hadronsϕ,K−as well as their ratioϕ/K−and proton high-order cumulants with our model calculations,we nd that hadronic interactions play a dominant role in these collisions.

Threshold Structures in Hadron Spectrum and Hadronic Molecules

Numerous candidates for exotic hadrons have been detected experimentally in the past two decades,predominantly near the threshold of a pair of hadrons.This study aims to investigate the overall behavior of nearthreshold line shapes in invariant mass distributions.It is noteworthy that the threshold cusp might manifest as a peak only in channels with attractive interaction.The assertion is made that there should be near-threshold structures for any heavy-quark and heavy-antiquark hadron pairs exhibiting attractive interaction at the threshold,as observed in the invariant mass distribution of heavy quarkonium and light hadrons that couple to the open-flavor hadron pair.Furthermore,we have conducted an analysis of potential hadronic molecules comprising pairs of heavy hadrons,utilizing the Bethe-Salpeter equation with constant interactions derived from the one-boson-exchange model.Observed candidates for these hadronic molecules are in good agreement with our predicted spectrum.

Isospin-conserving hadronic decay of the D_(s1)(2460) into D_(s)π^(+)π^(-)

The internal structure of the charm-strange mesons D_(s0)^(*)(2317)and D_(s1)(2460)are the subject of intensive studies.Their widths are small because they decay dominantly through isospinbreaking hadronic channels D_(s0)^(*)(2317)^(+)→D_(s)^(+)π^(0) and D _(s1)(2460)^(+)→D_(s)^(*+)π^(0).The D_(s1)(2460)can also decay into the hadronic final states D_(s)^(+)ππ,conserving isospin.In that case there is,however,a strong suppression from phase space.We study the transition D_(s1)(2460)^(+)→D_(s)^(+)π^(+)π^(-)in the scenario that the D_(s1)(2460)is a D^(*)K hadronic molecule.The ππ final state interaction is taken into account through dispersion relations.We find that the ratio of the partial widths of the Γ(D_(s1)(2460)^(+)→D_(s)^(+)π^(+)π^(-)) / Γ(D_(s1)(2460)^(+)→D_(s)^(*+)π^(0))obtained in the molecular picture is consistent with the existing experimental measurement.More interestingly,we demonstrate that theπ+π−invariant mass distribution shows a double bump structure,which can be used to disentangle the hadronic molecular picture from the compact state picture for the D_(s1)(2460)^(+).Predictions on the B_(s1)^(0)→B_(s)^(0)π^(+)π^(-)are also made.

A survey of heavy–heavy hadronic molecules

The spectrum of hadronic molecules composed of heavy-antiheavy charmed hadrons has been obtained in our previous work.The potentials are constants at the leading order,which are estimated from resonance saturation.The experimental candidates of hadronic molecules,say X(3872),Y(4260),three P_(c)states and P_(cs)(4459),fit the spectrum well.The success in describing the pattern of heavy-antiheavy hadronic molecules stimulates us to give more predictions for the heavy-heavy cases,which are less discussed in literature than the heavy-antiheavy ones.Given that the heavy-antiheavy hadronic molecules,several of which have strong experimental evidence,emerge from the dominant constant interaction from resonance saturation,we find that the existence of many heavy-heavy hadronic molecules is natural.Among these predicted heavy-heavy states we highlight the DD;molecule and the D^(*)∑_(c)^(*)molecules,which are the partners of the famous X(3872)and Pc states.Quite recently,LHCb collaboration reported a doubly charmed tetraquark state,T_(cc),which is in line with our results for the DD^(*)molecule.With the first experimental signal of this new kind of exotic states,the upcoming update of the LHCb experiment as well as other experiments will provide more chances of observing the heavy-heavy hadronic molecules.

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 1/2sNN=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.

A study of hadronic shower development in the ECAL of the alpha magnetic spectrometer Ⅱ

In this paper, we studied the development of hadronic shower in an electromagnetic calorimeter of Alpha Magnetic Spectrometer Ⅱ. Two parametrized empirical formulae were proposed to describe the hadronic shower shape in calorimeter. Using 100 GeV proton beam incident on the center of the ECAL, detailed plots of lateral and longitudinal hadronic shower behavior were given and we found the formulae can describe the development of the hadronic shower with the test beam data. The possible application of the parametrized formulae including e±-π± discrimination and tau jet reconstruction was discussed.

Relationship between quark-antiquark potential and quark-antiquark free energy in hadronic matter

In high-temperature quark-gluon plasma and its subsequent hadronic matter created in a high-energy nucleus-nucleus collision, the quark-antiquark potential depends on the temperature. The temperature-dependent potential is expected to be derived from the free energy obtained in lattice gauge theory calculations. This requires one to study the relationship between the quark-antiquark potential and the quark-antiquark free energy. When the system＇s temperature is above the critical temperature, the potential of a heavy quark and a heavy antiquark almost equals the free energy, but the potential of a light quark and a light antiquark, of a heavy quark and a light antiquark and of a light quark and a heavy antiquark is substantially larger than the free energy. When the system＇s temperature is below the critical temperature, the quark-antiquark free energy can be taken as the quark-antiquark potential. This allows one to apply the quark-antiquark free energy to study hadron properties and hadron-hadron reactions in hadronic matter.

The medium-temperature dependence of jet transport coefficient in high-energy nucleus-nucleus collisions

The medium-temperature T dependence of the jet transport coefficient̂q was studied via the nuclear modification factor RAA(p_(T))and elliptical flow parameter v_(2)(p_(T))for large transverse momentum p_(T) hadrons in high-energy nucleus-nucleus collisions.Within a next-to-leading-order perturbative QCD parton model for hard scatterings with modified fragmentation functions due to jet quenching controlled by q,we check the suppression and azimuthal anisotropy for large p_(T) hadrons,and extract q by global fits to RAA(pT)and v_(2)(pT)data in A+A collisions at RHIC and LHC,respectively.The numerical results from the best fits show that q∕T^(3) goes down with local medium-temperature T in the parton jet trajectory.Compared with the case of a constant q∕T^(3),the going-down T dependence of q∕T^(3) makes a hard parton jet to lose more energy near T_(c) and therefore strengthens the azimuthal anisotropy for large pT hadrons.As a result,v_(2)(p_(T))for large pT hadrons was enhanced by approximately 10%to better fit the data at RHIC/LHC.Considering the first-order phase transition from QGP to the hadron phase and the additional energy loss in the hadron phase,v_(2)(p_(T))is again enhanced by 5-10%at RHIC/LHC.

Quantum Chromodynamics on Lattice: Direct Minimization of QCD-QED-Action with New Results

This paper describes a new numerical QCD calculation method (direct minimization of QCD-QED-action) and its results for the first-generation (u, d) hadrons. Here we start with the standard color-Lagrangian LQCD = LDirac + Lgluon, model the quarks qi as parameterized gaussians, and the gluons Agi as Ritz-Galerkin-series. We minimize the Lagrangian numerically with parameters par = (par (q), {αk}, par (Ag)) for first-generation hadrons (nucleons, pseudo-scalar mesons, vector mesons). The resulting parameters yield the correct masses and correct magnetic moments for the nucleons, the gluon-distribution and the quark-distribution with interesting insights into the hadron structure.

Relativistic Heavy Ion Collider and the Large Hadron Collider for Heavy Ion Fusion

Heavy Ion Fusion makes use of the Relativistic Heavy Ion Collider at Brookhaven National Lab and the Large Hadron Collider in Geneva, Switzerland for Inertial Confinement Fusion. Two Storage Rings, which may or may not initially be needed, added to each of the Colliders increases the intensity of the Heavy Ion Beams making it comparable to the Total Energy delivered to the DT target by the National Ignition Facility at the Lawrence Livermore Lab. The basic Physics involved gives Heavy Ion Fusion an advantage over Laser Fusion because heavy ions have greater penetration power than photons. The Relativistic Heavy Ion Collider can be used as a Prototype Heavy Ion Fusion Reactor for the Large Hadron Collider.

The Substructure of Elementary Particles Demonstrated by the I-Theory

Present studies in physics assume that elementary particles are the building blocks of all matter, and that they are zero-dimensional objects which do not occupy space. The new I-Theory predicts that elementary particles do indeed have a substructure, three dimensions, and occupy space, being composed of fundamental particles called I-particles. In this article we identify the substructural pattern of elementary particles and define the quanta of energy that form each elementary particle. We demonstrate that the substructure comprises two classes of quanta which we call “attraction quanta” and “repulsion quanta”. We create a model that defines the rest-mass energy of each elementary particle and can predict new particles. Lastly, in order to incorporate this knowledge into the contemporary models of science, a revised periodic table is proposed.