Related papers: A new approach to quarkonium polarization studies
We highlight issues which are often underestimated in the experimental analyses on quarkonium polarization: the relation between the parameters of the angular distributions and the angular momentum composition of the quarkonium, the…
Polarization measurements are usually considered as the most difficult challenge for the QCD description of quarkonium production. In fact, global data fits for the determination of the non-perturbative parameters of bound-state formation…
Polarization measurements are the best instrument to understand how quark and antiquark combine into the different quarkonium states, but no model has so far succeeded in explaining the measured J/psi and Upsilon polarizations. On the other…
The di-fermion angular distribution observed in decays of inclusively produced vector particles is characterized by two frame-independent observables, reflecting the average spin-alignment of the produced particle and the magnitude of…
Most recent calculations of quarkonium production are based on the NRQCD factorization formalism. This formalism is reviewed. To make predictions about specific cross section, universal NRQCD matrix elements need to be extracted from…
I discuss NRQCD and, in particular, the NRQCD factorization formalism for quarkonium production and decay. I also summarize the current status of the comparison between the predictions of NRQCD factorization and experimental measurements.
We investigate the renormalization properties of the shape function formalism for inclusive production of $P$-wave heavy quarkonia, which arises from resumming a class of corrections coming from kinematical effects associated with the…
Linearly polarized emission is described, in general, in terms of the Stokes parameters $Q$ and $U$, from which the polarization intensity and polarization angle can be determined. Although the polarization intensity and polarization angle…
One of the key ways in which quantum mechanics differs from relativity is that it requires a fixed background reference frame for spacetime. In fact, this appears to be one of the main conceptual obstacles to uniting the two theories.…
Quarkonium production is a sensitive probe of the dynamics of hard scattering, which can `measure' the environment of the heavy quark pair after it is created in a hard process. Quarkonium hadroproduction data indicates that the produced…
Several fixed-target experiments reported J/$\psi$ and $\Upsilon$ polarization measurements, as functions of Feynman $x$ ($x_{\rm F}$) and transverse momentum ($p_{\rm T}$), in three different polarization frames, using different…
I discuss the current status of the comparison between quarkonium-production measurements and the predictions of the NRQCD factorization formalism.
We introduce a theoretical framework for resource-efficient characterization and control of non-Markovian open quantum systems, which naturally allows for the integration of given, experimentally motivated, control capabilities and…
Viewing frames of reference as physical systems, subject to the same laws as the systems they describe, is central to the relational approach in physics. Under the assumption that quantum mechanics universally governs all physical entities,…
The observation of unpolarized quarkonium production in high energy pp collisions, at mid rapidity, implies a significant violation of the non-relativistic QCD (NRQCD) velocity scaling rules. A precise experimental confirmation of this…
While non-relativistic QCD (NRQCD) foresees a variety of elementary quarkonium production mechanisms naturally leading to state-dependent kinematic patterns, the LHC cross sections and polarization measurements reveal a remarkably simple…
A shape of invariant differential cross section for hadron production as function of transverse momentum is analysed. The systematic analysis of the available data demonstrates a need for a modification of the parameterization traditionally…
Quarkonium decays are studied in the charmonium model. Relativistic corrections, higher-order perturbative QCD corrections and non- perturbative contributions are discussed. Recent measurements of charmonium annihilation rates are used to…
As a stringent test of the nonrelativistic QCD factorization approach for inclusive heavy-quarkonium production in high-energy hadron collision, the polarized heavy-quarkonium production at the Tevatron is discussed. The polarization of…
Polarization measurements provide a detailed method to test the Standard Model and to search for new physics. Most previous studies depend on pre-selected coordinates, which blurs the significance of the results. The construction of two…