Related papers: Holographic spin alignment for vector mesons
The GlueX experiment at Jefferson Lab aims to study the light meson spectrum with an emphasis on the search for hybrid mesons. To this end, a linearly-polarized $9\,$GeV photon beam impinges on a hydrogen target contained within a detector…
We propose a relativistic theory for spin density matrices of vector mesons based on Kadanoff-Baym equations in the closed-time-path formalism. The theory puts the calculation of spin observables such as the spin density matrix element…
In this paper, we study total and differential observables of electro- and photoproduction of light $\rho$, $\omega$ and $\phi$ mesons as functions of the center-of-mass energy of the $\gamma p$ collision and momentum transfer squared…
We provide a framework to analyze the electroproduction process ep -> ep rho with a polarized target, writing the angular distribution of the rho decay products in terms of spin density matrix elements that parameterize the hadronic…
The GlueX experiment at Jefferson Lab studies photoproduction of mesons using linearly polarized $8.5\,\text{GeV}$ photons impinging on a hydrogen target which is contained within a detector with near-complete coverage for charged and…
A two-component model is developed for diffractive electroproduction of $\rho^0$, $\phi$ and $\jpsi$, based on non-perturbative and perturbative two-gluon exchange. This provides a common kinematical structure for non-perturbative and…
We discuss the consequence of global polarization of the produced quarks in non-central heavy-ion collisions on the spin alignment of vector mesons. We show that the alignment is quite different for different hadronization scenarios. These…
Exclusive production of light vector mesons in deep inelastic scattering is calculated at next-to-leading order in the dipole picture in the limit of high photon virtuality. The resulting expression is free of any divergences and suitable…
We develop a non-perturbative analysis of the electro-production of heavy vector mesons ($\phi$, $J/\Psi$) from threshold to high energy. We use the holographic construction with bulk confinement enforced through a soft wall. Using Witten…
Spin alignments of vector mesons and hyperons in relativistic heavy-ion collisions have been proposed as signals of the global polarization. The STAR experiment first observed the $\rm \Lambda$ polarization. Recently, the ALICE…
We study light hadron leptoproduction at small $x$. Vector meson production is analysed in terms of generalized gluon distributions with taking into account the transverse quark motion. Within a two-gluon model the double spin asymmetries…
Dark matter haloes in cosmological filaments and walls have their spin vector aligned (in average) with their host structure. While haloes in walls are aligned with the plane of the wall independently of their mass, haloes in filaments…
We study the phenomenology of the recently proposed modified version of the Soft-Wall model of holographic QCD with a negative dilaton profile. We investigate vector and scalar mesons, evaluating mass spectra, decay constants and two-point…
Recent experimental results on global polarization of hyperons and spin alignment of vector mesons in heavy-ion collisions are reviewed, especially in context of the energy dependence and particle species dependence. New results on local…
Spin asymmetries provide a wide range of insights into nucleon structure and hadronization. Recent measurements of beam spin asymmetries of $\pi^+\pi^-$ dihadrons from Semi-Inclusive Deep Inelastic Scattering (SIDIS) at CLAS12 provide the…
We derive helicity amplitudes for diffractive leptoproduction of the S and D wave states of vector mesons. We predict a dramatically different spin dependence for production of the S and D wave vector mesons. We find very small…
Exclusive production of $\phi$ mesons on hydrogen and deuterium targets is studied in the HERMES kinematic region $1 < Q^{2} < 7$ GeV$^2$ and $3.0 < W < 6.3$ GeV. Spin density matrix elements and their $Q^{2}$ and $t$ dependences are…
Unstable particles (such as the vector mesons) have an important role to play in low mass dilepton production resulting from heavy ion collisions and this has been a subject of several investigations. Yet subtleties, such as the…
We analyse spin effects in diffractive vector meson leptoproduction at small $x$ on the basis of the generalized parton distribution (GPD) approach. We take into account quark transverse degrees of freedom in the hard subprocess. We…
We provide an analysis of vector meson photoproduction in the channel of the vector meson decaying into a pseudoscalar meson plus a photon, i.e. $V\to P\gamma$. It is shown that non-trivial kinematic correlations arise from the measurement…