The thermal modification of the exclusive decay <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msubsup><mi>K</mi><mn>1</mn><mo>+</mo></msubsup><mrow><mo>(</mo><mn>1270</mn><mo>)</mo></mrow><mo>→</mo><msup><mi>π</mi><mo>+</mo></msup><msup><mi>π</mi><mo>−</mo></msup><msup><mi>K</mi><mo>+</mo></msup></mrow></math> in a hot hadronic medium is studied. The decay amplitude is constructed from effective hadronic interactions dominated by the <math xmlns="http://www.w3.org/1998/Math/MathML"><mi>ρ</mi></math>- and <math xmlns="http://www.w3.org/1998/Math/MathML"><msup><mi>K</mi><mo>*</mo></msup></math>-pole contributions, thereby enabling a Dalitz-level analysis of the three-body decay in the medium. Thermal effects associated with partial chiral-symmetry restoration are incorporated through a phenomenological interpolation toward vector–axial-vector degeneracy near the chiral crossover. As the temperature increases, the reduction of the parent <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>K</mi><mn>1</mn></msub></math> mass strongly compresses the available three-body phase space, leading to substantial deformation of the Dalitz distribution and invariant-mass spectra, as well as to a pronounced suppression of <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msub><mi mathvariant="normal">Γ</mi><mrow><msub><mi>K</mi><mn>1</mn></msub><mo>→</mo><msup><mi>π</mi><mo>+</mo></msup><msup><mi>π</mi><mo>−</mo></msup><msup><mi>K</mi><mo>+</mo></msup></mrow></msub><mrow><mo>(</mo><mi>T</mi><mo>)</mo></mrow></mrow></math>. As a further step toward future transport-based phenomenological comparisons, Normalized shape observables are introduced to quantify the thermal evolution of the <math xmlns="http://www.w3.org/1998/Math/MathML"><msup><mi>K</mi><mo>*</mo></msup></math>-dominated <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>π</mi><mi>K</mi></mrow></math> region, the upper-edge weight of the <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>π</mi><mi>π</mi></mrow></math> spectrum, and the compactification of the Dalitz population. The dominant effect identified in the present framework is therefore kinematic: thermal phase-space reduction in the strange axial-vector channel. These results suggest that the exclusive <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msub><mi>K</mi><mn>1</mn></msub><mrow><mo>(</mo><mn>1270</mn><mo>)</mo></mrow></mrow></math> channel may provide a useful qualitative probe of in-medium strange axial-vector dynamics near the pseudocritical region.

South Korea

Seung-il Nam

Thermal modification of <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msub><mi>K</mi><mn>1</mn></msub><mrow><mo>(</mo><mn>1270</mn><mo>)</mo></mrow><mo>→</mo><msup><mi>π</mi><mo>+</mo></msup><msup><mi>π</mi><mo>−</mo></msup><msup><mi>K</mi><mo>+</mo></msup></mrow></math> in a hot hadronic medium

In the extended Linear-<math xmlns="http://www.w3.org/1998/Math/MathML"><mi>σ</mi></math> Model (eLSM), the chiral phase structure of meson states, including pseudoscalars (<math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msup><mi>J</mi><mrow><mi>p</mi><mi>c</mi></mrow></msup><mo>=</mo><msup><mn>0</mn><mrow><mo>−</mo><mo>+</mo></mrow></msup></mrow></math>), scalars (<math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msup><mi>J</mi><mrow><mi>p</mi><mi>c</mi></mrow></msup><mo>=</mo><msup><mn>0</mn><mrow><mo>+</mo><mo>+</mo></mrow></msup></mrow></math>), vectors (<math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msup><mi>J</mi><mrow><mi>p</mi><mi>c</mi></mrow></msup><mo>=</mo><msup><mn>1</mn><mrow><mo>−</mo><mo>−</mo></mrow></msup></mrow></math>), and axial vectors (<math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msup><mi>J</mi><mrow><mi>p</mi><mi>c</mi></mrow></msup><mo>=</mo><msup><mn>1</mn><mrow><mo>+</mo><mo>+</mo></mrow></msup></mrow></math>), is investigated with the mean-field approximation. A systematic comparison between SU(3) and SU(4) configurations is provided. It has been found that the estimations of meson masses derived from SU(4) eLSM are more congruent with experimental values than those derived from SU(3) eLSM. Consequently, we conclude that an increase in quark degrees of freedom significantly enhances the accuracy of meson mass simulations. We investigate the effect of temperature on the masses of various meson states calculated in the SU(3) and SU(4) eLSM. After establishing all the fitting parameters, the temperature dependence of meson masses shows that although various meson states exhibit unique patterns in their mass changes with temperature, they all seem to share a similar range of dissolution temperatures. This means that the critical temperature that marks the phase transition from hadrons to quarks appears to vary slightly depending on the meson states. In this regard, we find that the quarkonium states, formed by a quark and its antiquark, are largely unaffected by variations in the temperature.

JINR

A. Friesen

Yu. Kalinovsky

Saudi Arabia

S.O. Allehabi

Egypt

N.M. Rfeek

A.A. Alshehri

A. Tawfik

Temperature dependence of the masses of various meson states: A comparative study in the SU(3) and SU(4) extended linear-<math xmlns="http://www.w3.org/1998/Math/MathML"><mi>σ</mi></math> models

Using the <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>HYDJET</mi><mrow><mo>+</mo><mo>+</mo></mrow></mrow></math> model, we study the production of multistrange particles <math xmlns="http://www.w3.org/1998/Math/MathML"><mo>(</mo><mi>ϕ</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML"><mi mathvariant="normal">Ω</mi><mo>)</mo></math> in <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>Au</mi><mo>+</mo><mi>Au</mi></mrow></math> collisions at <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msqrt><msub><mi>s</mi><mrow><mi>N</mi><mi>N</mi></mrow></msub></msqrt><mo>=</mo></mrow></math> 11.5, 19.6, 27, 39, and 200 GeV as functions of transverse momentum and centrality. The model calculations employ earlier freeze-out hypersurfaces for multistrange particle production and are compared with STAR experimental data. Results indicate that the ++ model demonstrates a better agreement with experimental data for multistrange particles at higher energies, particularly in relation to early thermal freeze-out. Meanwhile, the default version performs more accurately for lighter, nonstrange particles at the same energy scales. We also analyze identified particle and mixed particle ratios, providing insights into strangeness enhancement. The results provide additional constraints on parton energy loss models, contributing to a more precise determination of the transport properties of hot and dense QCD matter.

India

Gauri Devi

Satya Ranjan Nayak

B.K. Singh

Particle production in <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>Au</mi><mo>+</mo><mi>Au</mi></mrow></math> collisions at <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msqrt><msub><mi>s</mi><mrow><mi>N</mi><mi>N</mi></mrow></msub></msqrt><mo>=</mo><mn>11.5</mn><mo>−</mo><mn>200</mn><mspace width="0.16em"></mspace><mi>GeV</mi></mrow></math> using the <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>HYDJET</mi><mrow><mo>+</mo><mo>+</mo></mrow></mrow></math> framework

The global spin polarization of hyperons in heavy-ion collisions have been investigated by including spin-correlation effects among their constituent quarks. The available data on global spin polarizations of hyperons and spin alignments of vector mesons provide constraints on phase-space functions of the spin polarization and correlation. These constraints can lead to inequalities under some approximations, which might provide possible clues for the presence of quark spin correlation inside hyperons at lower collision energies.

Italy

Lucia Oliva

China

Qun Wang

Germany

Xin-Nian Wang

Quark spin correlation inside hyperons

As an extended and more complete version of the primary QCD nucleation model presented in [<a href="http://dx.doi.org/10.1103/PhysRevC.95.024907">Phys. Rev. C 95, 024907 (2017)</a>], the new model introduces explicitly the transition balance and formulates it in both macroscopic and microscopic descriptions. The microscopic description of the transition balance in QCD nucleation is implemented in a kinetic parton cascade model and tested for a first-order phase transition from gluons to pions in a one-dimensional expansion with Bjorken boost invariance.

Tianzhe Zhou

Qiuze Sun

Jin Hu

Carsten Greiner

Zhe Xu

Transition balance in QCD nucleation

We present the yield, average transverse momentum, and collective flow calculations of <math xmlns="http://www.w3.org/1998/Math/MathML"><msup><mi>K</mi><mrow><mo>*</mo><mn>0</mn></mrow></msup></math> resonances in <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>Au</mi><mo>+</mo><mi>Au</mi></mrow></math> collisions at <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msqrt><msub><mi>s</mi><mrow><mi>N</mi><mi>N</mi></mrow></msub></msqrt><mo>=</mo><mn>19.6</mn></mrow></math>, 14.5, and 7.7 GeV using the AMPT model. It is found that, due to hadronic rescattering, the decay daughters of <math xmlns="http://www.w3.org/1998/Math/MathML"><msup><mi>K</mi><mrow><mo>*</mo><mn>0</mn></mrow></msup></math> interact with other particles in the medium, causing the yield of reconstructable <math xmlns="http://www.w3.org/1998/Math/MathML"><msup><mi>K</mi><mrow><mo>*</mo><mn>0</mn></mrow></msup></math> to be significantly suppressed, especially at low transverse momentum. The model results are compared with recent experimental data from Phase-II of the Beam Energy Scan (BES-II) program at the Relativistic Heavy-Ion Collider. The string-melting version of the AMPT model successfully reproduces the measured <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msup><mi>K</mi><mrow><mo>*</mo><mn>0</mn></mrow></msup><mo>/</mo><mi>K</mi></mrow></math> ratios at all three analyzed collision energies. Interestingly, AMPT calculations that exclude the hadronic phase nevertheless provide a reasonable description of the data, thereby challenging the conventional interpretation that hadronic rescattering is the primary mechanism responsible for suppressing the <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msup><mi>K</mi><mrow><mo>*</mo><mn>0</mn></mrow></msup><mo>/</mo><mi>K</mi></mrow></math> ratio in central heavy-ion collisions. In addition, we find that the <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msup><mi>K</mi><mrow><mo>*</mo><mn>0</mn></mrow></msup><mo>/</mo><mi>K</mi></mrow></math> ratio appears to be largely insensitive to the lifetime of the hadronic phase, whereas the average transverse momentum, <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mo>〈</mo><msub><mi>p</mi><mi>T</mi></msub><mo>〉</mo></mrow></math>, of the <math xmlns="http://www.w3.org/1998/Math/MathML"><msup><mi>K</mi><mrow><mo>*</mo><mn>0</mn></mrow></msup></math> shows a strong dependence, increasing significantly as the lifetime of the hadronic phase becomes longer. We further show that the directed flow <math xmlns="http://www.w3.org/1998/Math/MathML"><mo>(</mo><msub><mi>v</mi><mn>1</mn></msub><mo>)</mo></math> of <math xmlns="http://www.w3.org/1998/Math/MathML"><msup><mi>K</mi><mrow><mo>*</mo><mn>0</mn></mrow></msup></math> mesons is strongly influenced by hadronic rescattering, whereas the elliptic flow <math xmlns="http://www.w3.org/1998/Math/MathML"><mo>(</mo><msub><mi>v</mi><mn>2</mn></msub><mo>)</mo></math> exhibits only weak sensitivity to hadronic effects. These results establish <math xmlns="http://www.w3.org/1998/Math/MathML"><msup><mi>K</mi><mrow><mo>*</mo><mn>0</mn></mrow></msup></math> directed flow as a sensitive probe of the late-stage hadronic medium in heavy-ion collisions. These model calculations therefore provide valuable insight into the underlying physics governing the observed experimental results at RHIC.

Pranjal Barik

Kadambini Menduli

Aswini Kumar Sahoo

Md. Nasim

<math xmlns="http://www.w3.org/1998/Math/MathML"><msup><mi>K</mi><mrow><mo>*</mo><mn>0</mn></mrow></msup></math> meson production using a multiphase transport model at RHIC BES energies

The production of <math xmlns="http://www.w3.org/1998/Math/MathML"><msubsup><mi mathvariant="normal">Λ</mi><mi>c</mi><mo>+</mo></msubsup></math> baryons in <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>Pb</mi><mo>+</mo><mi>Pb</mi></mrow></math> collisions at <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msqrt><msub><mi>s</mi><mrow><mi>N</mi><mi>N</mi></mrow></msub></msqrt><mo>=</mo><mn>5.02</mn></mrow></math> TeV is investigated within the quark recombination framework, including the energy loss of light and charm quarks inside the hot and dense medium. The model simultaneously describes the transverse momentum (<math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>p</mi><mi>T</mi></msub></math>) spectra of <math xmlns="http://www.w3.org/1998/Math/MathML"><msubsup><mi mathvariant="normal">Λ</mi><mi>c</mi><mo>+</mo></msubsup></math> baryons, <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msubsup><mi mathvariant="normal">Λ</mi><mi>c</mi><mo>+</mo></msubsup><mo>/</mo><msup><mi>D</mi><mn>0</mn></msup></mrow></math> yield ratio, which is attributed to the dominance of the quark recombination mechanism in the quark-gluon plasma), and the second harmonic coefficient of <math xmlns="http://www.w3.org/1998/Math/MathML"><msubsup><mi mathvariant="normal">Λ</mi><mi>c</mi><mo>+</mo></msubsup></math> baryons with emphasis on the effects of minijets on the azimuthal anisotropy. Furthermore, we extend the theoretical calculation to <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>Pb</mi><mo>+</mo><mi>Pb</mi></mrow></math> collisions at <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msqrt><msub><mi>s</mi><mrow><mi>N</mi><mi>N</mi></mrow></msub></msqrt><mo>=</mo><mn>2.76</mn></mrow></math> TeV and make predictions for <math xmlns="http://www.w3.org/1998/Math/MathML"><msubsup><mi mathvariant="normal">Λ</mi><mi>c</mi><mo>+</mo></msubsup></math> baryons and <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msubsup><mi mathvariant="normal">Λ</mi><mi>c</mi><mo>+</mo></msubsup><mo>/</mo><msup><mi>D</mi><mn>0</mn></msup></mrow></math> yield ratio. The simultaneous description of the yield, baryon-to-meson ratio, and azimuthal anisotropy further validates that the recombination model is an effective hadronization mechanism in heavy-ion collisions.

Jing-Zong Zhang

Hua Zheng

Lilin Zhu

Hadronization of <math xmlns="http://www.w3.org/1998/Math/MathML"><msubsup><mi mathvariant="normal">Λ</mi><mrow><mi>c</mi></mrow><mo>+</mo></msubsup></math> baryons from a recombination model in <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>Pb</mi><mo>+</mo><mi>Pb</mi></mrow></math> collisions at energies available at the CERN Large Hadron Collider

We develop a novel model utilizing the forward <math xmlns="http://www.w3.org/1998/Math/MathML"><msup><mi>K</mi><mo>*</mo></msup></math> production reaction off the nucleon, <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>π</mi><mi>N</mi><mo>→</mo><msup><mi>K</mi><mo>*</mo></msup><mi>M</mi><mi>B</mi></mrow></math>, induced by a high-momentum <math xmlns="http://www.w3.org/1998/Math/MathML"><mi>π</mi></math> beam, as a tool to study low-lying <math xmlns="http://www.w3.org/1998/Math/MathML"><msup><mi>Y</mi><mo>*</mo></msup></math> resonances below and just above the <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mover accent="true"><mi>K</mi><mo>¯</mo></mover><mi>N</mi></mrow></math> threshold. Because conventional <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msup><mi>K</mi><mo>−</mo></msup><mi>p</mi></mrow></math> scattering experiments face difficulties in directly accessing this kinematic region, the proposed reaction offers a valuable complementary approach for <math xmlns="http://www.w3.org/1998/Math/MathML"><msup><mi>Y</mi><mo>*</mo></msup></math> spectroscopy. The constructed model is based on the one-meson exchange mechanism, which is known to dominate forward-angle production at high energies, and the half-off-shell scattering amplitudes from the ANL-Osaka dynamical coupled-channels models (Model A and Model B). We predict various observables, including differential cross sections and angular distributions. Our results demonstrate significant enhancements in the sub-threshold region of the invariant mass spectra. Notably, we show that overlapping resonances, such as a potential new <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mn>3</mn><mo>/</mo><msup><mn>2</mn><mo>+</mo></msup></mrow><mo> </mo><mi mathvariant="normal">Σ</mi></math> state and the well-established <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi mathvariant="normal">Σ</mi><mrow><mo>(</mo><mn>1385</mn><mo>)</mo></mrow><mn>3</mn><mo>/</mo><msup><mn>2</mn><mo>+</mo></msup></mrow></math>, can constitute a single peak in the <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>π</mi><mi mathvariant="normal">Λ</mi></mrow></math> mass spectrum, indicating that the existence of previously unconfirmed subthreshold states cannot be ruled out by analyzing only the existing mass spectrum data. Furthermore, we find that angular distributions provide strong discriminatory power to disentangle such overlapping states through partial-wave interference effects, while the <math xmlns="http://www.w3.org/1998/Math/MathML"><msup><mi>t</mi><mo>′</mo></msup></math> and <math xmlns="http://www.w3.org/1998/Math/MathML"><msubsup><mi>ϕ</mi><mi>M</mi><mo>*</mo></msubsup></math> dependencies provide crucial constraints on the high-energy production mechanisms. Our predictions for these highly sensitive observables can facilitate high-statistics measurements, which are accessible at modern hadron facilities such as J-PARC, to unravel the <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>S</mi><mo>=</mo><mo>−</mo><mn>1</mn></mrow><mo> </mo><msup><mi>Y</mi><mo>*</mo></msup></math> mass spectrum.

Japan

H. Kamano

United States

T.S.H. Lee

Low-lying <math xmlns="http://www.w3.org/1998/Math/MathML"><mi mathvariant="normal">Λ</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML"><mi mathvariant="normal">Σ</mi></math> resonances studied with the forward <math xmlns="http://www.w3.org/1998/Math/MathML"><msup><mi>K</mi><mo>*</mo></msup></math> productions off the proton induced by a high-momentum <math xmlns="http://www.w3.org/1998/Math/MathML"><mi>π</mi></math> beam

In our earlier work [A. C. Wang et al., <a href="http://dx.doi.org/10.1103/PhysRevC.98.045209">Phys. Rev. C 98, 045209 (2018)</a>], we analyzed the differential cross-section data from the CLAS Collaboration for the reactions <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>γ</mi><mi>p</mi><mo>→</mo><msup><mi>K</mi><mrow><mo>*</mo><mo>+</mo></mrow></msup><msup><mi mathvariant="normal">Σ</mi><mn>0</mn></msup></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>γ</mi><mi>p</mi><mo>→</mo><msup><mi>K</mi><mrow><mo>*</mo><mn>0</mn></mrow></msup><msup><mi mathvariant="normal">Σ</mi><mo>+</mo></msup></mrow></math> using an effective Lagrangian approach. We found that a satisfactory description of the data required the inclusion of the <math xmlns="http://www.w3.org/1998/Math/MathML"><mi>s</mi></math>-channel <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi mathvariant="normal">Δ</mi><mrow><mo>(</mo><mn>1905</mn><mo>)</mo></mrow><mn>5</mn><mo>/</mo><msup><mn>2</mn><mo>+</mo></msup></mrow></math> resonance, in addition to <math xmlns="http://www.w3.org/1998/Math/MathML"><mi>t</mi></math>-channel exchanges of <math xmlns="http://www.w3.org/1998/Math/MathML"><mi>K</mi><mo>,</mo><mo> </mo><mi>κ</mi></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML"><msup><mi>K</mi><mo>*</mo></msup><mo>,</mo><mo> </mo><mi>s</mi></math>-channel contributions from nucleon (<math xmlns="http://www.w3.org/1998/Math/MathML"><mi>N</mi></math>) and <math xmlns="http://www.w3.org/1998/Math/MathML"><mi mathvariant="normal">Δ</mi><mo>,</mo><mo> </mo><mi>u</mi></math>-channel exchanges of <math xmlns="http://www.w3.org/1998/Math/MathML"><mi mathvariant="normal">Λ</mi><mo>,</mo><mo> </mo><mi mathvariant="normal">Σ</mi></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML"><msup><mi mathvariant="normal">Σ</mi><mo>*</mo></msup></math>, and a generalized contact term. In the present work, we extend our analysis to incorporate the data on spin density matrix elements from the LEPS Collaboration for the <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>γ</mi><mi>p</mi><mo>→</mo><msup><mi>K</mi><mrow><mo>*</mo><mn>0</mn></mrow></msup><msup><mi mathvariant="normal">Σ</mi><mo>+</mo></msup></mrow></math> reaction at photon energies <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msub><mi>E</mi><mi>γ</mi></msub><mo>=</mo><mn>1.85</mn><mo>–</mo><mn>2.96</mn><mspace width="0.28em"></mspace><mi>GeV</mi></mrow></math>. Our goal is to impose more stringent constraints on the theoretical model and obtain a more reliable understanding of the reaction mechanisms. We obtain two fits that describe the experimental data equally well. In both fits, the <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi mathvariant="normal">Δ</mi><mrow><mo>(</mo><mn>1905</mn><mo>)</mo></mrow><mn>5</mn><mo>/</mo><msup><mn>2</mn><mo>+</mo></msup></mrow></math> resonance plays an important role. However, the contribution from <math xmlns="http://www.w3.org/1998/Math/MathML"><mi>t</mi></math>-channel <math xmlns="http://www.w3.org/1998/Math/MathML"><mi>κ</mi></math> exchange is significant in one fit but negligible in the other. This finding contradicts earlier claims in the literature that the LEPS parity spin asymmetry <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>P</mi><mi>σ</mi></msub></math> data support a dominant role of <math xmlns="http://www.w3.org/1998/Math/MathML"><mi>κ</mi></math> exchange in <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>γ</mi><mi>p</mi><mo>→</mo><msup><mi>K</mi><mrow><mo>*</mo><mn>0</mn></mrow></msup><msup><mi mathvariant="normal">Σ</mi><mo>+</mo></msup></mrow></math>. We also present predictions for <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>P</mi><mi>σ</mi></msub></math> at <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msub><mi>E</mi><mi>γ</mi></msub><mo>=</mo><mn>8.5</mn></mrow></math> GeV, which may help clarify whether <math xmlns="http://www.w3.org/1998/Math/MathML"><mi>κ</mi></math> exchange is indeed dominant in this reaction.

Ai-Chao Wang

Neng-Chang Wei

Fei Huang

Combined analysis of the data on cross sections and spin density matrix elements for <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msup><mi>K</mi><mo>*</mo></msup><mi mathvariant="normal">Σ</mi></mrow></math> photoproduction reactions

Purely baryonic weak decays of heavy baryons are investigated within the framework of the Skyrme model. These decays belong to a new class of unobserved decay channels, which would help us to test the standard model, particularly potential sources of <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi mathvariant="italic">CP</mi></mrow></math> violation in the baryonic sector. By interpreting the heavy baryon as a bound state of a heavy meson and a baryon (Skyrmion), a direct calculation of the decay process <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msub><mi mathvariant="normal">Λ</mi><mi>b</mi></msub><mo>→</mo><mi>p</mi><mover accent="true"><mi>p</mi><mo>¯</mo></mover><mi>n</mi></mrow></math> is performed. The resulting branching fraction is of <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>O</mi><mo>(</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>6</mn></mrow></msup><mo>)</mo></mrow></math>, in agreement with previous estimates.

Chao-Qiang Geng

Chao Han

Purely baryonic weak decays of heavy baryons in a Skyrme model