Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userDouble Exotic States Productions in Pion and Kaon Induced Reactions
78
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
In the present work, we investigate the production of $P_{c}$ and $Z_c(3900)/Z_{cs}(3985)$ states in the processes of $pi p rightarrow Z_{c}(3900) P_{c} $/$Kprightarrow Z_{cs}(3985) P_{c}$ with an effective Lagrangian approach. Our estimations indicates that the cross sections depends on the model parameters and beam energies, in particular, the cross sections for $pi p to Z_c(3900) P_c(4312)$ and $pi p to Z_c(3900) P_c(4440)$ are similar and can reach up to 10 nb, while those for $pi p to Z_c(3900) P_c(4457)$ can be 30 nb. As for $Kp to Z_{cs}(3985)P_c$, the cross sections are about 2.5 times smaller than those for $pi p to Z_c(3900) P_c$. The discussed processes in the present work, especially $pi p to Z_c(3900) P_c(4457)$, may be accessible by the the high-energy pion and kaon beams in the facilities of J-PARC and COMPASS.
rate research
Read More
We investigate the reaction $pi^- p to pi^- J/psi p$ via the open-charm hadron rescattering diagrams. Due to the presence of the triangle singularity (TS) in the rescattering amplitudes, the TS peaks can simulate the pentaquark-like resonances arising in the $J/psi p$ invariant mass distributions, which may bring ambiguities on our understanding of the nature of the exotic states. Searching for the heavy pentaquark in different processes may help us to clarify the ambiguities, because of the highly process-dependent characteristic of the TS mechanism.
Many charmonium-like and bottomonium-like $XYZ$ resonances have been observed by the Belle, Babar, CLEO and BESIII collaborations in the past decade. They are difficult to fit in the conventional quark model and thus are considered as candidates of exotic hadrons, such as multi-quark states, meson molecules, and hybrids. In this talk, we first briefly introduce the method of QCD sum rules and then provide a short review of the mass spectra of the quarkonium-like tetraquark states and the heavy quarkonium hybrids in the QCD sum rules approach. Possible interpretations of the $XYZ$ resonances are briefly discussed.
Some of the recent progress in the physics of pion production induced by neutrinos on nucleons and nuclei is reviewed from a theoretical perspective. The importance of Watsons theorem to reconcile ANL and BNL data with the off-diagonal Goldberger-Treiman relation for the $Delta(1232)$ is discussed. The disagreement between MiniBooNE data and theoretical calculations is presented in the light of the new MINERvA data. The coherent pion production data on $^{12}$C obtained by MINERvA are also compared to different microscopic and PCAC models.
Within the three-flavor PNJL and EPNJL chiral quark models we have obtained pseudoscalar meson properties in quark matter at finite temperature $T$ and baryochemical potential $mu_B$. We compare the meson pole (Breit-Wigner) approximation with the Beth-Uhlenbeck (BU) approach that takes into account the continuum of quark-antiquark scattering states when determining the partial densities of pions and kaons. We evaluate the kaon-to-pion ratios along the (pseudo-)critical line in the $T-mu_B$ plane as a proxy for the chemical freezeout line, whereby the variable $x=T/mu_B$ is introduced that corresponds to the conserved entropy per baryon as initial condition for the heavy-ion collision experiments. We present a comparison with the experimental pattern of kaon-to-pion ratios within the BU approach and using $x$-dependent pion and strange quark potentials. A sharp horn effect in the energy dependence $K^+/pi^+$ ratio is explained by the enhanced pion production at energies above $sqrt{s_{NN}}=8$ GeV, when the system enters the regime of meson dominance. This effect is in line with the enhancement of low-momentum pion spectra that is discussed as a precursor of the pion Bose condensation and entails the occurrence of a nonequilibrium pion chemical potential of the order of the pion mass. We elucidate that the horn effect is not related to the existence of a critical endpoint in the QCD phase diagram.
There are two mass generating mechanisms in the standard model of particle physics (SM). One is related to the Higgs boson and fairly well understood. The other is embedded in quantum chromodynamics (QCD), the SMs strong interaction piece; and although responsible for emergence of the roughly 1 GeV mass scale that characterises the proton and hence all observable matter, the source and impacts of this emergent hadronic mass (EHM) remain puzzling. As bound states seeded by a valence-quark and -antiquark, pseudoscalar mesons present a simpler problem in quantum field theory than that associated with the nucleon. Consequently, there is a large array of robust predictions for pion and kaon properties whose empirical validation will provide a clear window onto many effects of both mass generating mechanisms and the constructive interference between them. This has now become significant because new-era experimental facilities, in operation, construction, or planning, are capable of conducting such tests and thereby contributing greatly to resolving the puzzles of EHM. These aspects of experiment, phenomenology, and theory, along with contemporary successes and challenges, are sketched herein, simultaneously highlighting the potential gains that can accrue from a coherent effort aimed at finally reaching an understanding of the character and structure of Natures Nambu-Goldstone modes.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
