Hadronic decays of the (pseudo-)scalar charmonium states ηc\eta_c and χc0\chi_{c0} in the extended Linear Sigma Model

We study the phenomenology of the ground-state (pseudo-)scalar charmonia $\eta_c$ and $\chi_{c0}$ in the framework of a $U(4)_r \times U(4)_l$ symmetric linear sigma model with (pseudo-)scalar and (axial-) vector mesons. Based on previous results for the spectrum of charmonia and the spectrum and (OZI-dominant) strong decays of open charmed mesons, we extend the study of this model to OZI-suppressed charmonia decays. This includes decays into 'ordinary' mesons but also particularly interesting channels with scalar-isoscalar resonances $f_0(1370),\, f_0(1500),\, f_0(1710)$ that may include sizeable contributions from a scalar glueball. We study the variation of the corresponding decay widths assuming different mixings between glueball and quark-antiquark states. We also compute the decay width of the pseudoscalar $\eta_c$ into a pseudoscalar glueball. In general, our results for decay widths are in reasonable agreement with experimental data where available. Order of magnitude predictions for as yet unmeasured states and channels are potentially interesting for BESIII, Belle II, LHCb as well as the future PANDA experiment at the FAIR facility.Comment: 20 pages, 3 figures, 6 tabe

Factors influencing academic and employment outcomes: a multiphase Q-methodology study

This thesis investigates the perceptions of barriers and enablers impacting academic and employment outcomes of students of Generation Z. It is a topic of multi-disciplinary importance spanning the fields of education, business and management, psychology and sociology. It is framed within a changing UK Higher Education landscape including increased internationalisation. This study adopts Q-methodology, a mixed-methods study that quantitatively evaluates qualitative viewpoints. Q-methodology is extended by performing additional analyses at the intersection of gender, ethnicity, and nationality. A total of 304 students, 44 non-higher-education employees and 8 faculty members, voiced their opinions to explain gaps in student attainment. Moreover, degree results from 2,024 students who graduated between July 2016 and July 2019 from one single UK business school, were evaluated. Findings of a self-reported lack of confidence of female students, linked partly to a perceived lack of verbal communication skills, suggest that one of the consequences of a lack of confidence might be that female students work harder than their male counterparts to compensate, resulting in a higher mean average grade. By doing so, they tend not to take advantage of more longterm networking and career opportunities, and also feel more stressed, which, in turn, further diminishes self-confidence. Tackling the confidence and verbal communication gap is currently deprioritised by faculty, who focus on knowledge transmission as part of their teaching. Suggestions are made that aim to raise awareness of more informed and nuanced teaching practices that embed verbal communication skills, to develop student agency independent of gender. By keeping the first part of each research phase in line with traditional Q-methodology, and by then adding accessible R-type analyses, it was possible to reveal results that aim to raise awareness for more audiencecentric teaching and research practices across Q and non-Q communities

JPEG2000 Image Compression on Solar EUV Images

For future solar missions as well as ground-based telescopes, efficient ways to return and process data have become increasingly important. Solar Orbiter, e.g., which is the next ESA/NASA mission to explore the Sun and the heliosphere, is a deep-space mission, which implies a limited telemetry rate that makes efficient onboard data compression a necessity to achieve the mission science goals. Missions like the Solar Dynamics Observatory (SDO) and future ground-based telescopes such as the Daniel K. Inouye Solar Telescope, on the other hand, face the challenge of making petabyte-sized solar data archives accessible to the solar community. New image compression standards address these challenges by implementing efficient and flexible compression algorithms that can be tailored to user requirements. We analyse solar images from the Atmospheric Imaging Assembly (AIA) instrument onboard SDO to study the effect of lossy JPEG2000 (from the Joint Photographic Experts Group 2000) image compression at different bit rates. To assess the quality of compressed images, we use the mean structural similarity (MSSIM) index as well as the widely used peak signal-to-noise ratio (PSNR) as metrics and compare the two in the context of solar EUV images. In addition, we perform tests to validate the scientific use of the lossily compressed images by analysing examples of an on-disk and off-limb coronal-loop oscillation time-series observed by AIA/SDO.Comment: 25 pages, published in Solar Physic

Consumption processes and positively homogeneous projection properties

We constructively prove the existence of time-discrete consumption processes for stochastic money accounts that fulfill a pre-specified positively homogeneous projection property (PHPP) and let the account always be positive and exactly zero at the end. One possible example is consumption rates forming a martingale under the above restrictions. For finite spaces, it is shown that any strictly positive consumption strategy with restrictions as above possesses at least one corresponding PHPP and could be constructed from it. We also consider numeric examples under time-discrete and -continuous account processes, cases with infinite time horizons and applications to income drawdown and bonus theory.Comment: 24 pages, 2 figure

Computation of unsteady transonic flows through rotating and stationary cascades. 3: Acoustic far-field analysis

A small perturbation type analysis has been developed for the acoustic far field in an infinite duct extending upstream and downstream of an axial turbomachinery stage. The analysis is designed to interface with a numerical solution of the near field of the blade rows and, thereby, to provide the necessary closure condition to complete the statement of infinite duct boundary conditions for the subject problem. The present analysis differs from conventional inlet duct analyses in that a simple harmonic time dependence was not assumed, since a transient signal is generated by the numerical near-field solution and periodicity is attained only asymptotically. A description of the computer code developed to carry out the necessary convolutions numerically is included, as well as the results of a sample application using an impulsively initiated harmonic signal