In the framework of the nuclear spectral function approach for incoherent primary proton-nucleon and secondary pion-nucleon production processes we study the inclusive Λ(1520)-hyperon production in ...the interaction of 2.83-GeV protons with nuclei. In particular, the
A
and momentum dependences of the absolute and relative Λ(1520)-hyperon yields are investigated within the different scenarios for their in-medium width. Our model calculations show that the pion-nucleon production channel contributes distinctly to the “low-momentum” Λ(1520) creation both in light and heavy nuclei in the chosen kinematics and, hence, has to be taken into consideration on close examination of the dependences of the Λ(1520)-hyperon yields on the target mass number with the aim to get information on their width in the medium. They also demonstrate that both the
A
dependence of the relative Λ(1520)-hyperon production cross section and momentum dependence of the absolute Λ(1520)-hyperon yield at incident energy of interest are appreciably sensitive to the Λ(1520) in-medium width, which means that these observables may be an important tool to determine the above width.
Nucl.Phys.A 1047(2024)122876 We study the production of $X(3872)$ mesons in photon-induced nuclear
reactions near the threshold within the collision model based on the nuclear
spectral function. The ...model accounts for direct photon-nucleon $X(3872)$
production processes as well as five different scenarios for their internal
structure. We calculate the absolute and relative excitation functions for
$X(3872)$ production off $^{12}$C and $^{184}$W target nuclei at near-threshold
incident photon energies of 8--16 GeV, the absolute differential cross sections
for their production off these target nuclei at laboratory angles of
0$^{\circ}$--10$^{\circ}$ and for incident photon energy of 13 GeV as well as
the A dependences of the relative (transparency ratios) cross sections for
$X(3872)$ production from ${\gamma}A$ collisions at photon energies around 13
GeV within the adopted scenarios for the $X(3872)$ meson internal structure. We
show that the absolute and relative observables considered reveal distinct
sensitivity to these scenarios. Therefore, the measurement of such observables
in a dedicated experiment at the CEBAF facility in the near-threshold energy
range will allow us to get valuable information on the $X(3872)$ inner
structure.
We study the \(\Upsilon(1S)\) meson photoproduction on protons and nuclei at the near-threshold center-of-mass energies below 11.4 GeV (or at the corresponding photon laboratory energies ...\(E_{\gamma}\) below 68.8 GeV). We calculate the absolute excitation functions for the non-resonant and resonant photoproduction of \(\Upsilon(1S)\) mesons off protons at incident photon laboratory energies of 63--68 GeV by accounting for direct (\({\gamma}p \to {\Upsilon(1S)}p\)) and two-step (\({\gamma}p \to P^+_b(11080,11125,11130) \to {\Upsilon(1S)}p\)) \(\Upsilon(1S)\) production channels within different scenarios for the non-resonant total cross section of elementary reaction \({\gamma}p \to {\Upsilon(1S)}p\) and for branching ratios of the decays \(P^+_b(11080,11125,11130) \to {\Upsilon(1S)}p\). We also calculate an analogous functions for photoproduction of \(\Upsilon(1S)\) mesons on \(^{12}\)C and \(^{208}\)Pb target nuclei in the near-threshold center-of-mass beam energy region of 9.0--11.4 GeV by considering respective incoherent direct (\({\gamma}N \to {\Upsilon(1S)}N\)) and two-step (\({\gamma}p \to P^+_b(11080,11125,11130) \to {\Upsilon(1S)}p\), \({\gamma}n \to P^0_b(11080,11125,11130) \to {\Upsilon(1S)}n\)) \(\Upsilon(1S)\) production processes within a nuclear spectral function approach. We show that a detailed scan of the \(\Upsilon(1S)\) total photoproduction cross section on a proton and nuclear targets in the near-threshold energy region in future high-precision experiments at the proposed high-luminosity electron-ion colliders EIC and EicC in the U.S. and China should give a definite result for or against the existence of the non-strange hidden-bottom pentaquark states \(P_{bi}^+\) and \(P_{bi}^0\) (\(i=\)1, 2, 3) as well as clarify their decay rates.
In the framework of the nuclear spectral function approach for incoherent primary proton-nucleon and secondary pion-nucleon production processes we study the inclusive {Lambda}(1520)-hyperon ...production in the interaction of 2.83-GeV protons with nuclei. In particular, the A and momentum dependences of the absolute and relative {Lambda}(1520)-hyperon yields are investigated within the different scenarios for their in-medium width. Our model calculations show that the pion-nucleon production channel contributes distinctly to the 'low-momentum' {Lambda}(1520) creation both in light and heavy nuclei in the chosen kinematics and, hence, has to be taken into consideration on close examination of the dependences of the {Lambda}(1520)-hyperon yields on the target mass number with the aim to get information on their width in the medium. They also demonstrate that both the A dependence of the relative {Lambda}(1520)-hyperon production cross section and momentum dependence of the absolute {Lambda}(1520)-hyperon yield at incident energy of interest are appreciably sensitive to the {Lambda}(1520) in-medium width, which means that these observables may be an important tool to determine the above width.
Nucl.Phys.A 1037(2023)122687 Accounting for the LHCb observation that the reported hidden-charm strange
pentaquark $P_{cs}(4459)^0$ can split into two substructures, $P_{cs}(4455)^0$
and ...$P_{cs}(4468)^0$, with a mass difference of 13 MeV as well as the newly
observed hidden-charm pentaquark resonance $P_{cs}(4338)^0$ with strangeness,
we study within the double-peak scenario for the $P_{cs}(4459)^0$ state the
near-threshold $J/\psi$ meson production from protons and nuclei by considering
incoherent direct non-resonant (${K^-}p \to {J/\psi}\Lambda$) and two-step
resonant (${K^-}p \to P_{csi}^0 \to {J/\psi}\Lambda$, $i=1$, 2, 3;
$P_{cs1}^{0}=P_{cs}(4338)^0$, $P_{cs2}^{0}=P_{cs}(4455)^0$,
$P_{cs3}^{0}=P_{cs}(4468)^0$) charmonium production processes with the main
goal of clarifying the possibility to observe within this scenario both above
two substructures contributing to the $P_{cs}(4459)^0$ state and the
$P_{cs}(4338)^0$ resonance in this production. We calculate the absolute
excitation functions, energy and momentum distributions for the non-resonant,
resonant and for the combined (non-resonant plus resonant) production of
$J/\psi$ mesons on protons as well as on carbon and tungsten target nuclei at
near-threshold incident antikaon beam momenta by assuming the spin-parity
assignments of the hidden-charm resonances $P_{cs}(4338)^0$, $P_{cs}(4455)^0$
and $P_{cs}(4468)^0$ as $J^P=(1/2)^-$, $J^P=(1/2)^-$ and $J^P=(3/2)^-$ within
four different realistic choices for the branching ratios of their decays to
the ${J/\psi}\Lambda$ mode (0.125, 0.25, 0.5 and 1\%) as well as for two
options for the branching fraction of their decays to the $K^-p$ channel (0.01
and 0.001\%). We show that these combined observables reveal clear sensitivity
to these scenarios. Hence, they may be an important tool to provide further
evidence for the existence of the above strange hidden-charm pentaquark
resonances.
Nucl.Phys.A 1032(2023)122624 The near-threshold pion-induced $\phi$ production off nuclei has been studied
in the kinematical conditions of the HADES experiment using a collision model
based on the ...nuclear spectral function. Starting from the elementary reaction
${\pi^-}p \to {\phi}n$, absolute differential and integral cross sections for
the production of $\phi$ mesons off a light carbon and a heavy tungsten target
have been calculated and compared to the recently reported experimental cross
sections. The absolute cross section values are shown to be sensitive to the
effective nuclear scalar $\phi$ and neutron potentials while the transparency
ratio is governed by the ${\phi}N$ absorption cross section. The experimental
data are found to be consistent with an attractive ${\phi}$-nucleus potential
of $\approx$ -(50--100) MeV at normal nuclear matter density $\rho_0$ and an
effective ${\phi}N$ absorption cross section of $\approx$ 12--25 mb. The
extracted $\phi$-nucleus potential is deeper than previous theoretical and
experimental findings as well as those obtained in the present work within the
($t{\rho}$) approximation with accounting for Pauli correlations from the
spin-averaged $\phi$-$p$ scattering length reported in a recent ALICE
experiment.
Nucl.Phys.A 1029(2023)122562 We study the near-threshold $J/\psi$ meson photoproduction from protons and
nuclei by considering incoherent direct non-resonant (${\gamma}p \to
{J/\psi}p$, ${\gamma}n ...\to {J/\psi}n$) and two-step resonant (${\gamma}p \to
P_{ci}^+ \to {J/\psi}p$, ${\gamma}n \to P_{ci}^0 \to {J/\psi}n$, $i=1$, 2, 3,
4; $P_{c1}^{+,0}=P_c^{+,0}(4312)$, $P_{c2}^{+,0}=P_c^{+,0}(4337)$,
$P_{c3}^{+,0}=P_c^{+,0}(4440)$, $P_{c4}^{+,0}=P_c^{+,0}(4457)$) charmonium
production processes. We calculate the absolute excitation functions, energy
and momentum distributions for the non-resonant, resonant and for the combined
(non-resonant plus resonant) production of $J/\psi$ mesons on protons as well
as, using the nuclear spectral function approach, on carbon and tungsten target
nuclei at near-threshold incident photon energies by assuming the spin-parity
assignments of the hidden-charm resonances $P_{c}^{+,0}(4312)$,
$P_{c}^{+,0}(4337)$, $P_{c}^{+,0}(4440)$ and $P_{c}^{+,0}(4457)$ as
$J^P=(1/2)^-$, $J^P=(1/2)^-$, $J^P=(1/2)^-$ and $J^P=(3/2)^-$ within three
different realistic scenarios for the branching ratios of their decays to the
${J/\psi}p$ and ${J/\psi}n$ modes (0.25, 0.5 and 1%). We show that will be very
hard to measure the $P_{ci}^+$ pentaquark states through the scan of the
$J/\psi$ total photoproduction cross section on a proton target in the
near-threshold energy region around the resonant photon energies of 9.44,
9.554, 10.04 and 10.12 GeV if these branching ratios $\sim$ 1% and less. We
also demonstrate that at these photon beam energies the $J/\psi$ energy and
momentum combined distributions considered reveal distinct sensitivity to the
above scenarios, respectively, at "low" $J/\psi$ total energies and momenta,
which implies that they may be an important tool to provide further evidence
for the existence of the pentaquark $P_{ci}^+$ and $P_{ci}^0$ resonances.
Nucl.Phys.A 1023(2022)122452 We study the near-threshold $J/\psi$ meson production on protons and nuclei
by considering incoherent direct non-resonant $K^-p \to {J/\psi}\Lambda$ and
two-step resonant ...${K^-}p \to P_{cs}(4459)^0 \to {J/\psi}\Lambda$ charmonium
production processes. We calculate the absolute excitation functions, energy
and momentum distributions for the non-resonant, resonant and for the combined
(non-resonant plus resonant) production of $J/\psi$ mesons off protons as well
as off carbon and tungsten target nuclei at near-threshold incident antikaon
energies by considering these elementary production channels as well as by
assuming the spin-parity assignment of the hidden-charm resonance
$P_{cs}(4459)^0$ with strangeness as $J^P=(3/2)^-$ within six different
scenarios for the branching ratio $BrP_{cs}(4459)^0 \to {J/\psi}\Lambda$ of
the decay $P_{cs}(4459)^0 \to {J/\psi}\Lambda$. We show that the combined
observables considered reveal definite sensitivity to these scenarios, which
means that they may be an important tool to provide further evidence for the
existence of the pentaquark $P_{cs}(4459)^0$ resonance and to get valuable
information on its decay rate to the ${J/\psi}\Lambda$ final state. Their
measurements could be performed in the future at the J-PARC Hadron Experimental
Facility.
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