Spin Flipper, Neutron Polarimetry, and Simulation, for the n3He Experiment

The n3He experiment constructed on FnPB [Fundamental neutron Physics Beamline-13] probes the PV [parity violating] nuclear force by measuring the statistical distribution of decay protons which result from the interaction of helium-3 nuclei with a beam of cold neutrons. Pulses of neutrons at 60 Hz are generated by the SNS [Spallation Neutron Source] from a 1 GeV proton beam colliding with a liquid Mercury target. Spalled neutrons are then focused into an intense cold neutron beam thru the use of a liquid hydrogen moderator and a neutron guide making the beam an effective tool as a low energy probe of the nuclear force. An essential instrument for the experiment is the high efficiency spin flipper. This is a state- of-the-art device based on the theory of double cosine-theta coils, and specifically constructed to prevent interference with other instrumentation in the experiment. Details of spin flipper design and integration are reported along with polarimetry and polarimetry measurements of spin flipper efficiency and beam polarization. A target yield analysis is also performed which precludes the construction of a yield profile simulation

Physical Correlations of the Scatter between Galaxy Mass, Stellar Content, and Halo Mass

We use the UniverseMachine to analyze the source of scatter between the central galaxy mass, the total stellar mass in the halo, and the dark matter halo mass. We also propose a new halo mass estimator, the cen+N mass: the sum of the stellar mass of the central and the N most massive satellites. We show that, when real space positions are perfectly known, the cen+N mass has scatter competitive with that of richness-based estimators. However, in redshift space, the cen+N mass suffers less from projection effects in the UniverseMachine model. The cen+N mass is therefore a viable low scatter halo mass estimator, and should be considered an important tool to constrain cosmology with upcoming spectroscopic data from DESI. We analyze the scatter in stellar mass at fixed halo mass and show that the total stellar mass in a halo is uncorrelated with secondary halo properties, but that the central stellar mass is a function of both halo mass and halo age. This is because central galaxies in older halos have had more time to grow via accretion. If the UniverseMachine model is correct, accurate galaxy-halo modeling of mass selected samples therefore needs to consider halo age in addition to mass.Comment: 13 pages, 11 figures, submitted to MNRA

Not-for-Profit Boards Need to Be More Diverse

Women have made great strides in being represented on not-for-profit boards. But board members from different ethnic backgrounds and visible minorities have made much less progress. Boards with greater diversity are the most effective.York’s Knowledge Mobilization Unit provides services and funding for faculty, graduate students, and community organizations seeking to maximize the impact of academic research and expertise on public policy, social programming, and professional practice. It is supported by SSHRC and CIHR grants, and by the Office of the Vice-President Research & Innovation. [email protected]

Weak Lensing Reveals a Tight Connection Between Dark Matter Halo Mass and the Distribution of Stellar Mass in Massive Galaxies

Using deep images from the Hyper Suprime-Cam (HSC) survey and taking advantage of its unprecedented weak lensing capabilities, we reveal a remarkably tight connection between the stellar mass distribution of massive central galaxies and their host dark matter halo mass. Massive galaxies with more extended stellar mass distributions tend to live in more massive dark matter haloes. We explain this connection with a phenomenological model that assumes, (1) a tight relation between the halo mass and the total stellar content in the halo, (2) that the fraction of in-situ and ex-situ mass at $r<10$ kpc depends on halo mass. This model provides an excellent description of the stellar mass functions (SMF) of total stellar mass ($M_{\star}^{\rm Max}$) and stellar mass within inner 10 kpc ($M_{\star}^{10}$) and also reproduces the HSC weak lensing signals of massive galaxies with different stellar mass distributions. The best-fit model shows that halo mass varies significantly at fixed total stellar mass (as much as 0.4 dex) with a clear dependence on $M_{\star}^{10}$. Our two-parameter $M_{\star}^{\rm Max}$-$M_{\star}^{10}$ description provides a more accurate picture of the galaxy-halo connection at the high-mass end than the simple stellar-halo mass relation (SHMR) and opens a new window to connect the assembly history of halos with those of central galaxies. The model also predicts that the ex-situ component dominates the mass profiles of galaxies at $r< 10$ kpc for $\log M_{\star} \ge 11.7$). The code used for this paper is available online: https://github.com/dr-guangtou/asapComment: 22 Pages, 12 Figures, 1 Table; Submitted to MNRAS. The model and Jupyter notebooks to reproduce the figures are available here: https://github.com/dr-guangtou/asa

Financial hardship and psychological distress: Exploring the buffering effects of religion

Despite ample precedent in theology and social theory, few studies have systematically examined the role of religion in mitigating the harmful effects of socioeconomic deprivation on mental health. The present study outlines several arguments linking objective and subjective measures of financial hardship, as well as multiple aspects of religious life, with psychological distress. Relevant hypotheses are then tested using data on adults aged 18–59 from the 1998 US NORC General Social Survey. Findings confirm that both types of financial hardship are positively associated with distress, and that several different aspects of religious life buffer against these deleterious influences. Specifically, religious attendance and the belief in an afterlife moderate the deleterious effects of financial hardship on both objective and subjective financial hardship, while meditation serves this function only for objective hardship. No interactive relationships were found between frequency of prayer and financial hardship. A number of implications, study limitations, and directions for future research are identified

The prevalence and impact of low back pain in pre-professional and professional dancers: a prospective study

Objectives To determine the prevalence of low back pain (LBP) in pre-professional and professional dancers and its impact on dance participation, care-seeking and medication use. Design Prospective cohort study. Setting One pre-professional ballet school, two pre-professional university dance programs, and a professional ballet company. Participants Male and female classical ballet and contemporary dancers. Main outcome measures An initial questionnaire collected demographic and LBP history data. The monthly prevalence of LBP (all episodes, activity limiting episodes and chronic LBP) and impact (activity limitation, care-seeking, and medication use) was collected over a nine-month period. Results 119 dancers participated, which represented 54% of those invited. Activity limiting LBP was reported by 52% of dancers, while chronic LBP was reported by 24%. Seventeen percent of all episodes of LBP resulted in some form of dance activity being completely missed. One-third of the sample reported care-seeking and one-fifth of the sample used medication. A history of LBP was associated with activity limiting LBP (p < 0.01; adjusted odds ratio: 3.98; 95% confidence interval: 1.44, 11.00). Conclusions LBP in dancers was common and had multiple impacts. This study reinforces the need for dancer access to healthcare professionals with expertise in evidence-based LBP prevention and management