Multidifferential study of identified charged hadron distributions in ZZ-tagged jets in proton-proton collisions at s=\sqrt{s}=13 TeV

Jet fragmentation functions are measured for the first time in proton-proton collisions for charged pions, kaons, and protons within jets recoiling against a $Z$ boson. The charged-hadron distributions are studied longitudinally and transversely to the jet direction for jets with transverse momentum 20 $< p_{\textrm{T}} < 100$ GeV and in the pseudorapidity range $2.5 < \eta < 4$. The data sample was collected with the LHCb experiment at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 1.64 fb$^{-1}$. Triple differential distributions as a function of the hadron longitudinal momentum fraction, hadron transverse momentum, and jet transverse momentum are also measured for the first time. This helps constrain transverse-momentum-dependent fragmentation functions. Differences in the shapes and magnitudes of the measured distributions for the different hadron species provide insights into the hadronization process for jets predominantly initiated by light quarks.Comment: All figures and tables, along with machine-readable versions and any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-013.html (LHCb public pages

Study of the B−→Λc+Λˉc−K−B^{-} \to \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-} K^{-} decay

The decay $B^{-} \to \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-} K^{-}$ is studied in proton-proton collisions at a center-of-mass energy of $\sqrt{s}=13$ TeV using data corresponding to an integrated luminosity of 5 $\mathrm{fb}^{-1}$ collected by the LHCb experiment. In the $\Lambda_{c}^+ K^{-}$ system, the $\Xi_{c}(2930)^{0}$ state observed at the BaBar and Belle experiments is resolved into two narrower states, $\Xi_{c}(2923)^{0}$ and $\Xi_{c}(2939)^{0}$, whose masses and widths are measured to be $$m(\Xi_{c}(2923)^{0}) = 2924.5 \pm 0.4 \pm 1.1 \,\mathrm{MeV}, \\ m(\Xi_{c}(2939)^{0}) = 2938.5 \pm 0.9 \pm 2.3 \,\mathrm{MeV}, \\ \Gamma(\Xi_{c}(2923)^{0}) = \phantom{000}4.8 \pm 0.9 \pm 1.5 \,\mathrm{MeV},\\ \Gamma(\Xi_{c}(2939)^{0}) = \phantom{00}11.0 \pm 1.9 \pm 7.5 \,\mathrm{MeV},$$ where the first uncertainties are statistical and the second systematic. The results are consistent with a previous LHCb measurement using a prompt $\Lambda_{c}^{+} K^{-}$ sample. Evidence of a new $\Xi_{c}(2880)^{0}$ state is found with a local significance of $3.8\,\sigma$, whose mass and width are measured to be $2881.8 \pm 3.1 \pm 8.5\,\mathrm{MeV}$ and $12.4 \pm 5.3 \pm 5.8 \,\mathrm{MeV}$, respectively. In addition, evidence of a new decay mode $\Xi_{c}(2790)^{0} \to \Lambda_{c}^{+} K^{-}$ is found with a significance of $3.7\,\sigma$. The relative branching fraction of $B^{-} \to \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-} K^{-}$ with respect to the $B^{-} \to D^{+} D^{-} K^{-}$ decay is measured to be $2.36 \pm 0.11 \pm 0.22 \pm 0.25$, where the first uncertainty is statistical, the second systematic and the third originates from the branching fractions of charm hadron decays.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-028.html (LHCb public pages

Measurement of the ratios of branching fractions R(D∗)\mathcal{R}(D^{*}) and R(D0)\mathcal{R}(D^{0})

The ratios of branching fractions $\mathcal{R}(D^{*})\equiv\mathcal{B}(\bar{B}\to D^{*}\tau^{-}\bar{\nu}_{\tau})/\mathcal{B}(\bar{B}\to D^{*}\mu^{-}\bar{\nu}_{\mu})$ and $\mathcal{R}(D^{0})\equiv\mathcal{B}(B^{-}\to D^{0}\tau^{-}\bar{\nu}_{\tau})/\mathcal{B}(B^{-}\to D^{0}\mu^{-}\bar{\nu}_{\mu})$ are measured, assuming isospin symmetry, using a sample of proton-proton collision data corresponding to 3.0 fb${ }^{-1}$ of integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The tau lepton is identified in the decay mode $\tau^{-}\to\mu^{-}\nu_{\tau}\bar{\nu}_{\mu}$. The measured values are $\mathcal{R}(D^{*})=0.281\pm0.018\pm0.024$ and $\mathcal{R}(D^{0})=0.441\pm0.060\pm0.066$, where the first uncertainty is statistical and the second is systematic. The correlation between these measurements is $\rho=-0.43$. Results are consistent with the current average of these quantities and are at a combined 1.9 standard deviations from the predictions based on lepton flavor universality in the Standard Model.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-039.html (LHCb public pages

The Laws of Image-nation: Brazilian racial tropes and the shadows of the slave quarters

CAPES Foundation, Proc. N. 09912-1; Birkbeck Institute for the Humanities, Birkbeck Law School and the Law and Image Reading Group funded and organized the ‘Law and Image Symposium’

Coaches’ experiences learning and applying the content of a humanistic coaching workshop in youth sport settings

The purpose of this study was to develop and deliver a humanistic coaching workshop, as well as investigate coaches’ perceptions of this workshop and their experiences using humanistic coaching. Participants were 12 coaches of grade 7–11 basketball teams from schools in low socioeconomic communities in a major Canadian city. Data were collected using semistructured interviews and personal journals. An inductive thematic analysis revealed coaches perceived the workshop to be effective in teaching the humanistic principles and how to apply them in youth sport settings. The perceived strengths of the workshop included the group discussions, use of videos, practical coaching examples, and learning about the findings from empirical studies. The participants applied the humanistic principles with their teams by asking questions that guided athlete learning and by requesting feedback about various individual and team matters. Despite facing challenges such as increased time and effort to implement humanistic coaching principles, the participants reported positive outcomes in their athletes related to autonomy, communication, motivation, and willingness to help teammates. These results are discussed using literature on youth sport coaching, knowledge translation, and youth development through sport. Findings from this study can be used to enhance youth sport coach training protocols

The Influence of Whole-Body Vibration on Creatine Kinase Activity and Jumping Performance in Young Basketball Players

PurposeTo quantify creatine kinase (CK) activity changes across time following an acute bout of whole-body vibration (WBV) and determine the association between changes in CK activity and jumping performance.MethodTwenty-six elite young basketball players were assigned to 3 groups: 36-Hz and 46-Hz vibration groups (G36 and G46, respectively) and a control group. the study quantified CK activity and jumping performance following an acute bout of WBV at 2 vibration frequencies. Both WBV groups performed a protocol that consisted of 10 sets of 60 s of WBV while standing on a vibration plate in a quarter-squat position. CK activity, countermovement jumps (CMJ), and squat jumps (SJ) were measured immediately before and 24hr and 48hr after WBV. in addition, CMJ and SJ were also measured 5min after WBV.ResultsCK activity was statistically significantly increased 24hr following WBV in G36 and G46. At 48hr after WBV, CK activity was similar to baseline levels in G36 but remained statistically significantly above baseline levels in G46. the CMJ and SJ heights were statistically significantly decreased at 5min following the protocol for both WBV groups. Overall, the changes in CK activity did not present a strong relationship with the changes in jump heights for any of the comparisons.ConclusionsThese findings suggest that WBV protocols with such characteristics may not cause excessive muscle damage and may partly explain why many WBV training studies have failed to elicit increases in strength performance.Univ Estadual Campinas, BR-13081970 Campinas, SP, BrazilUniversidade Federal de São Paulo, São Paulo, BrazilMcGill Univ, Montreal, PQ H3A 2T5, CanadaArizona State Univ, Tempe, AZ USAUniv Fed Goias, BR-75801615 Jatai, Go, BrazilUniversidade Federal de São Paulo, São Paulo, BrazilWeb of Scienc

Progression of Geographic Atrophy in Age-Related Macular Degeneration Imaged with Spectral Domain Optical Coherence Tomography

PURPOSE: To determine the area and enlargement rate (ER) of geographic atrophy (GA) in patients with age-related macular degeneration (AMD) using the spectral-domain optical coherence tomography (SDOCT) fundus image. DESIGN: Prospective longitudinal natural history study PARTICIPANTS: Eighty-six eyes of 64 patients with at least 6 months follow-up. METHODS: Patients with GA secondary to AMD were enrolled in this study. Macular scans were performed using the Cirrus SDOCT (Carl Zeiss Meditec, Dublin CA). The areas of GA identified on the SDOCT fundus images were quantified using a digitizing tablet. Reproducibility of these measurements was assessed and the ER of GA was calculated. The usefulness of performing square root transformations of the lesion area measurements was explored. MAIN OUTCOME MEASURE: Enlargement rate of GA RESULTS: At baseline, 27% of eyes had a single area of GA. The mean total area at baseline was 4.59mm(2) (1.8 disc areas (DA)). The mean follow up time was 1.24 years. Reproducibility, as assessed with the intraclass correlation coefficient (ICC), was excellent on both the original area scale (ICC = 0.995) and the square-root scale (ICC=0.996). Inter-grader differences were not an important source of variability in lesion size measurement (ICC=0.999, 0.997). On average, the ER of GA per year was 1.2 mm(2) (0.47 DA; range [0.01 - 3.61 mm(2)/year]. The ER correlated with the initial area of GA (r=0.45, p<0.001), but there were variable growth rates for any given baseline area. When the square root transformation of the lesion area measurements was used as a measure of lesion size, the enlargement rate (0.28 mm/yr) was not correlated with baseline size (r=-0.09,p=0.40). In this cohort of lesions, no correlation was found between ER and length of follow-up. Square root transformation of the data helped facilitate sample size estimates for controlled clinical trials involving GA. CONCLUSIONS: The SDOCT fundus image can be used to visualize and quantify GA. Advantages of this approach include the convenience and assurance of using a single imaging technique that permits simultaneous visualization of GA along with the loss of photoreceptors and the retinal pigment epithelium which should correlate with the loss of visual function