Hadronic Decays of Charm

Recent hadronic charm decay results from fixed-target experiments are presented. New measurements of the D0 to K-K+K-pi+ branching ratio are shown as are recent results from Dalitz plot fits to D+ to K-K+pi+, pi+pi-pi+, K-pi+pi+, K+pi-pi+ and D_s+ to pi+pi-pi+, K+pi-pi+. These fits include measurements of the masses and widths of several light resonances as well as strong evidence for the existence of two light scalar particles, the pipi resonance sigma and the Kpi resonance kappa.Comment: 8 pages, 9 figures, to appear in the proceedings for the 9th International Symposium on Heavy Flavors, Caltech, Pasadena, 10-13 Sept. 200

D0D^0--Dˉ0\bar{D}{}^0 hadronic mixing and DCS decays from FOCUS

We present an analysis of the decay $D^0 \to K^+\pi^-$ from FOCUS. From a sample of 234 events we find a branching ratio of $\frac{\Gamma(D^0 \to K^+\pi^-)}{\Gamma(D^0 \to K^-\pi^+)} = (0.430^{+0.062}_{-0.061}\pm 0.031)$ under the assumption of no mixing and no CP violation. We also present limits on charm mixing.Comment: Proceedings from talk at 2004 DPF Meeting at University of California, Riversid

Social work discourses and the social work interview

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.It will be argued that, in order to understand particular exchanges between social workers and clients, it is essential to go beyond the view that sees them simply in terms of interaction between unique persons, and locate them within the wider discursive settings within which they occur. Most of the talk which takes place in these interviews concerns problematic issues within family life, particularly in terms of the relationships between parents and children. Behind these apparently mundane conversations lie agendas of social work issues which have been constructed historically with the rise of the caring professions. The early part of the thesis is concerned with uncovering the historically constructed norms of acceptable motherhood which underpin social work strategies with families and which help set the agendas of interviews. Then the analysis focuses on how general norms and objectives are translated into operational, professional techniques. This theme is carried forward through a focus on the social settings in which interviews take place, the building up of subject positions within interviews, for social worker and client, and the implications of translating from a predominantly oral to a literate based, professional mode of discourse. Finally, the analysis is concerned with the tentative attempts, marked by ambiguity and resistance, to go beyond the mere monitoring of the life of the client, and draw her/him into a form of discourse which is openly committed to social work aims, where the client seems to want to present his or her life problems in terms which are intelligible to, and manageable within, the strategies open to the social worker

Pentaquark searches at FOCUS

We find no evidence for high-energy photoproduction of pentaquarks at 1540 MeV/$c^2$, 1862 MeV/$c^2$, or 3099 MeV/$c^2$ using decay modes $pK_S^0$, $\Xi^-\pi^-$, and $D^{(*)-}p$, respectively.Comment: Proceedings from talk at 2004 DPF Meeting at University of California, Riversid

Visual effects of wood on thermal perception of interior environments

There is a general consensus, supported by preliminary evidence, that exposed wood improves human perception of thermal comfort, though this idea has yet to be supported by meaningful effect sizes. This study sought to quantify human perception of thermal comfort of wood materials in a controlled laboratory setting. Participants experienced one of two wall treatments: exposed wooden wall panels and white-painted walls in a thermal environment set directly between "neutral” and "slightly warm” (81.5°F, 4Q%RH, PMV +Q.5). We hypothesized that participants exposed to the wood walls would gauge their thermal preference to be closer to neutral than that of participants who experienced the same thermal environment but with the white wall treatment. Wood was found to have a significant and moderate effect on thermal comfort, with the mean response of the participants who received the wood wall treatment being thermally preferable over that of the white wall (wood wall: M = Q.46, SD = Q.56; white wall: M = Q.68, SD = Q.51; p<Q.Q1)

Evaluating Volatile Organic Compound Emissions from Cross-Laminated Timber Bonded with a Soy-Based Adhesive

Volatile organic compound (VOC) emissions from indoor sources are large determinants of the indoor air quality (IAQ) and occupant health. Cross-laminated timber (CLT) is a panelized engineered wood product often left exposed as an interior surface finish. As a certified structural building product, CLT is currently exempt from meeting VOC emission limits for composite wood products and confirming emissions through California Department of Public Health (CDPH) Standard Method testing. In this study, small chamber testing was conducted to evaluate VOC emissions from three laboratory-produced CLT samples: One bonded with a new soy-based cold-set adhesive; a second bonded with a commercially available polyurethane (PUR) adhesive; and the third assembled without adhesive using dowels. A fourth commercially-produced eight-month-old sample bonded with melamine formaldehyde (MF) adhesive was also tested. All four samples were produced with Douglas-fir. The test results for the three laboratory-produced samples demonstrated VOC emissions compliance with the reference standard. The commercially-produced and aged CLT sample bonded with MF adhesive did not meet the acceptance criterion for formaldehyde of ≤9.0 µg/m3. The estimated indoor air concentration of formaldehyde in an office with the MF sample was 54.4 µg/m3; the results for the soy, PUR, and dowel samples were all at or below 2.5 µg/m3

Search for resonant production of strongly coupled dark matter in proton-proton collisions at 13 TeV

The first collider search for dark matter arising from a strongly coupled hidden sector is presented and uses a data sample corresponding to 138 fb&minus;1, collected with the CMS detector at the CERN LHC, at s&radic; = 13 TeV. The hidden sector is hypothesized to couple to the standard model (SM) via a heavy leptophobic Z&prime; mediator produced as a resonance in proton-proton collisions. The mediator decay results in two &ldquo;semivisible&rdquo; jets, containing both visible matter and invisible dark matter. The final state therefore includes moderate missing energy aligned with one of the jets, a signature ignored by most dark matter searches. No structure in the dijet transverse mass spectra compatible with the signal is observed. Assuming the Z&prime; boson has a universal coupling of 0.25 to the SM quarks, an inclusive search, relevant to any model that exhibits this kinematic behavior, excludes mediator masses of 1.5&ndash;4.0 TeV at 95% confidence level, depending on the other signal model parameters. To enhance the sensitivity of the search for this particular class of hidden sector models, a boosted decision tree (BDT) is trained using jet substructure variables to distinguish between semivisible jets and SM jets from background processes. When the BDT is employed to identify each jet in the dijet system as semivisible, the mediator mass exclusion increases to 5.1 TeV, for wider ranges of the other signal model parameters. These limits exclude a wide range of strongly coupled hidden sector models for the first time.</p

Study of quark and gluon jet substructure in Z plus jet and dijet events from pp collisions

Measurements of jet substructure describing the composition of quark- and gluon-initiated jets are presented. Proton-proton (pp) collision data at s&radic; = 13 TeV collected with the CMS detector are used, corresponding to an integrated luminosity of 35.9 fb&minus;1. Generalized angularities are measured that characterize the jet substructure and distinguish quark- and gluon-initiated jets. These observables are sensitive to the distributions of transverse momenta and angular distances within a jet. The analysis is performed using a data sample of dijet events enriched in gluon-initiated jets, and, for the first time, a Z+jet event sample enriched in quark-initiated jets. The observables are measured in bins of jet transverse momentum, and as a function of the jet radius parameter. Each measurement is repeated applying a &ldquo;soft drop&rdquo; grooming procedure that removes soft and large angle radiation from the jet. Using these measurements, the ability of various models to describe jet substructure is assessed, showing a clear need for improvements in Monte Carlo generators.</p

Search for long-lived particles produced in association with a Z boson in proton-proton collisions at root s=13 TeV

A search for long-lived particles (LLPs) produced in association with a Z boson is presented. The study is performed using data from proton-proton collisions with a center-of-mass energy of 13 TeV recorded by the CMS experiment during 2016&ndash;2018, corresponding to an integrated luminosity of 117 fb&minus;1. The LLPs are assumed to decay to a pair of standard model quarks that are identified as displaced jets within the CMS tracker system. Triggers and selections based on Z boson decays to electron or muon pairs improve the sensitivity to light LLPs (down to 15 GeV). This search provides sensitivity to beyond the standard model scenarios which predict LLPs produced in association with a Z boson. In particular, the results are interpreted in the context of exotic decays of the Higgs boson to a pair of scalar LLPs (H &rarr; SS). The Higgs boson decay branching fraction is constrained to values less than 6% for proper decay lengths of 10&ndash;100 mm and for LLP masses between 40 and 55 GeV. In the case of low-mass (&asymp; 15 GeV) scalar particles that subsequently decay to a pair of b quarks, the search is sensitive to branching fractions B(H &rarr; SS) &lt; 20% for proper decay lengths of 10&ndash;50 mm. The use of associated production with a Z boson increases the sensitivity to low-mass LLPs of this analysis with respect to gluon fusion searches. In the case of 15 GeV scalar LLPs, the improvement corresponds to a factor of 2 at a proper decay length of 30 mm.</p