Narrow Results

We studied the dependence of morphology and luminosity of the SDSS galaxies on the environmental factors. The environmental factors considered include the local density due to the nearest neighbor galaxy ρ_n, morphology of the nearest neighbor, and the large-scale background density. We found the local environment set up by the nearest neighbor galaxy gives strong effects on the galaxy morphology. The probability for a galaxy to have an early morphological type critically depends on whether or not ρ_n is above the virialization density. We conclude that the well-known morphology-density relation is basically due to the interactions between galaxy pairs. Dependence of galaxy morphology on the large-scale density is found only because there is a statistical correlation between the average pair separation and the large-scale background density. We also found that galaxy luminosity depends on ρ_n, and that, when the large-scale density is fixed, more isolated galaxies are more likely to be recent merger products. We propose a scenario that a series of morphology and luminosity transformation occur through a series of distant/close interactions and mergers, which results in the morphology-luminosity-local density relation.

Construction of future Muon Collider (or dedicated $\mu$-ring) tangential to the energy frontier $hh$ colliders will give opportunity to realize $\mu p$ and $\mu A$ collisions at multi-TeV center-of-mass energies with sufficiently high luminosities. Obviously, such colliders will essentially enlarge the physics search potential of corresponding muon and hadron colliders for both the SM (especially for clarifying QCD basics and confinement hypothesis) and BSM phenomena. In addition, they will provide parton distribution functions for adequate interpretation of energy frontier $hh$ colliders’ and cosmic ray experiments data. This paper is devoted to review of main parameters of $\mu h$ colliders proposed until now.

To achieve the design luminosity of $1\times 10^{35}{\mathrm{\text{cm}}}^{-2}{\mathrm{\text{s}}}^{-1}$, the Super Tau-Charm Facility (STCF) adopts an extremely low ${\beta }_y^{\ast }$ and a crab waist (CW) collision design. The extremely small vertical beam size at the interaction point and low vertical emittance required to achieve a beam–beam parameter of around 0.1 make the CW colliders highly susceptible to beam instabilities arising from beam–beam interactions. Some of these instabilities need to be carefully assessed and optimized through strong–strong beam–beam simulations. In this paper, we investigate the luminosity stability of the STCF design parameters using both weak–strong and strong–strong simulations. We also explore the influence of the CW scheme and various beam parameters on luminosity. These findings offer valuable insight to guide lattice design and optimize global parameters for STCF.

In this paper, we utilize the effective Lagrangian method within the tree-level Born approximation to explore $\varphi$-meson photoproduction, i.e. $\gamma p\to \varphi p$. Our analysis encompasses contributions from various sources, including the Pomeron, $f_1$-Regge, pseudoscalar particles ($\pi$, $\eta$), scalar particles ($a_0$, $f_0$), protons, and three-nucleon resonance states. In addition, we consider a possible pentaquark-like $K^{\ast }\mathrm{\Sigma }$-bound state $P_s$. The findings indicate that, apart from the region near the threshold, contributions other than the Pomeron generally have a limited impact on the total cross-section. However, alternative contributions become crucial at specific angles, particularly at smaller values of $cos\theta$. The incorporation of $P_s$ and other nucleon resonances proves essential to elucidate the bump observed near $W\sim 2.15$GeV at very forward angles and behaviors within the range of $W=(2.0-2.3)$GeV. Furthermore, in the region with $W\ge 2.5$GeV, where nucleon resonances become negligible, contributions from the t-channel mesons become pivotal. Our calculations for spin density matrix components, examined in various frames, exhibit improvement when considering all contributions. This comprehensive approach successfully reproduces the observed bump by including $P_s$. We also briefly estimate the $P_s$ production via $\varphi$-meson photoproduction in the future Electron-Ion Collider (EIC), resulting in the luminosity of 10 fb${}^{-1}$ per month.