Gender- and age-related changes in three dimensional facial profiles of healthy Northern Sudanese persons

The study aimed to provide quantitative information about gender-related normative data and growth changes between childhood and young adulthood in the soft tissue facial profiles of Northern Sudanese individuals. The three dimensional coordinates of 50 landmarks on the facial soft tissues were obtained using a hand-held laser scanner in 654 healthy Northern Sudanese subjects (327 males and 327 females) aged 4-30 years. The subjects were divided into 8 nonoverlapping age groups [1]. From selected landmarks, 15 facial angles were calculated and averaged for gender and age: upper, middle, and lower facial, and mandibular corpus convexities in the horizontal plane; relative position of the exocanthia and nasion; facial convexity in the sagittal plane; midfacial to mandibular plane, nasal convexity, nasolabial, mentolabial, interlabial, maxillary prominence, and left and right gonial angles. Comparisons were performed by factorial analysis of variance. On average men had larger facial and mandibular corpus convexities in the horizontal plane than women (ANOVA, p<0.01); on the contrary, no gender differences were found for facial convexities in the sagittal plane. Gender significantly influenced also the relative position of exocanthia and nasion, the maxillary prominence angle and the gonial angles (p<0.01). All analysed measurements were influenced by age (p<0.001): nasal convexity and interlabial angle increased from childhood to young adulthood, while mentolabial and gonial angles, horizontal facial convexity and sagittal facial convexity including the nose decreased as a function of age. No consistent age-related patterns were found for the other evaluated angles. Data collected in the current study can be used as a database for the quantitative description of facial profiles in Northern Sudanese subjects during normal growth and development

Morphological and functional facial asymmetry in patients with mild temporomandibular disorders: a pilot study

Facial asymmetry is normal in humans[1]. Authors indicated that facial asymmetry could influence the shape and function of the temporomandibular joints and vice versa[2]. In this study we collected preliminary reference values for facial asymmetry in adults with temporomandibular disorders (TMD), compared to a control group, using a 3D stereophotogrammetric imaging system and electromyographic (EMG) indices. Forty subjects (22 TMD; 18 control; paired for age: 21±2y) were recruited. Five linear measurements for each hemiface and asymmetry index (AI%) were computed from stereophotogrammetric scans. Standardized EMG indices for masseter and temporal muscles were obtained during clenching and gum chewing. Means of control and TMD groups were compared by t-test. For both groups, the AI for all linear measurements ranged from -10% to +10%; there was a great variability, especially for TMD group, who showed the higher values. For EMG indices, TMD group demonstrated a tendency to a more asymmetric muscular recruitment in static activities (masseter & temporal symmetry, C 87.5±1.76%; TMD 84.6±6.2%; p=0.06) and reduced symmetry during gum chewing (C 67.1± 20.9%; TMD 55.0±18.1%; p=0.06). The presence of higher asymmetry for stereophotogrammetry and EMG analyses, as well as the presence of alterations of masticatory function for the TMD group, suggest that this relationship should be further investigated. An analysis with a larger sample and with more severe TMD patients, together with a longitudinal study, is required to understand these possible relationships between morphology and function

Search for exotic decays of the Higgs boson to a pair of pseudoscalars in the μμ\mu\mubb and ττ\tau\taubb final states

International audienceA search for exotic decays of the Higgs boson (H) with a mass of 125 GeV to a pair of light pseudoscalars $\mathrm{a}_1$ is performed in final states where one pseudoscalar decays to two b quarks and the other to a pair of muons or $\tau$ leptons. A data sample of proton-proton collisions at $\sqrt{s}$ = 13 TeV corresponding to an integrated luminosity of 138 fb$^{-1}$ recorded with the CMS detector is analyzed. No statistically significant excess is observed over the standard model backgrounds. Upper limits are set at 95% confidence level (CL) on the Higgs boson branching fraction to $\mu\mu$bb and to $\tau\tau$bb, via a pair of $\mathrm{a}_1$s. The limits depend on the pseudoscalar mass $m_{\mathrm{a}_1}$ and are observed to be in the range (0.17-3.3) $\times$ 10$^{-4}$ and (1.7-7.7) $\times$ 10$^{2}$ in the $\mu\mu$bb and $\tau\tau$bb final states, respectively. In the framework of models with two Higgs doublets and a complex scalar singlet (2HDM+S), the results of the two final states are combined to determine model-independent upper limits on the branching fraction $\mathcal{B}$(H $\to$ $\mathrm{a}_1\mathrm{a}_1$ $\to$ $\ell\ell$bb) at 95% CL, with $\ell$ being a muon or a $\tau$ lepton. For different types of 2HDM+S, upper bounds on the branching fraction $\mathcal{B}$(H $\to$ $\mathrm{a}_1\mathrm{a}_1$) are extracted from the combination of the two channels. In most of the Type II 2HDM+S parameter space, $\mathcal{B}($H $\to$ $\mathrm{a}_1\mathrm{a}_1$) values above 0.23 are excluded at 95% CL for $m_{\mathrm{a}_1}$ values between 15 and 60 GeV

Muon identification using multivariate techniques in the CMS experiment in proton-proton collisions at s\sqrt{s} = 13 TeV

International audienceThe identification of prompt and isolated muons, as well as muons from heavy-flavour hadron decays, is an important task. We developed two multivariate techniques to provide highly efficient identification for muons with transverse momentum greater than 10\GeV. One provides a continuous variable as an alternative to a cut-based identification selection and offers a better discrimination power against misidentified muons. The other one selects prompt and isolated muons by using isolation requirements to reduce the contamination from nonprompt muons arising in heavy-flavour hadron decays. Both algorithms are developed using 59.7 fb$^{-1}$ of proton-proton collisions data at a centre-of-mass energy of $\sqrt{s}$ = 13 TeV collected in 2018 with the CMS experiment at the CERN LHC

Measurement of the primary Lund jet plane density in proton-proton collisions at s\sqrt{s} = 13 TeV

International audienceA measurement is presented of the primary Lund jet plane (LJP) density in inclusive jet production in proton-proton collisions. The analysis uses 138 fb$^{-1}$ of data collected by the CMS experiment at $\sqrt{s}$ = 13 TeV. The LJP, a representation of the phase space of emissions inside jets, is constructed using iterative jet declustering. The transverse momentum $k_\mathrm{T}$ and the splitting angle $\Delta R$ of an emission relative to its emitter are measured at each step of the jet declustering process. The average density of emissions as function of $\ln(k_\mathrm{T}$/GeV) and $\ln(R/\Delta R)$ is measured for jets with distance parameters $R$ = 0.4 or 0.8, transverse momentum $p_\mathrm{T} \gt$ 700 GeV, and rapidity $\vert y\vert \lt$ 1.7. The jet substructure is measured using the charged-particle tracks of the jet. The measured distributions, unfolded to the level of stable particles, are compared with theoretical predictions from simulations and with perturbative quantum chromodynamics calculations. Due to the ability of the LJP to factorize physical effects, these measurements can be used to improve different aspects of the physics modeling in event generators

Search for direct production of GeV-scale resonances decaying to a pair of muons in proton-proton collisions at s\sqrt{s} = 13 TeV

International audienceA search for direct production of low-mass dimuon resonances is performed using $\sqrt{s}$ = 13 TeV proton-proton collision data collected by the CMS experiment during the 2017-2018 operation of the CERN LHC with an integrated luminosity of 96.6 fb$^{-1}$. The search exploits a dedicated high-rate trigger stream that records events with two muons with transverse momenta as low as 3 GeV but does not include the full event information. The search is performed by looking for narrow peaks in the dimuon mass spectrum in the ranges of 1.1-2.6 GeV and 4.2-7.9 GeV. No significant excess of events above the expectation from the standard model background is observed. Model-independent limits on production rates of dimuon resonances within the experimental fiducial acceptance are set. Competitive or world's best limits are set at 90% confidence level for a minimal dark photon model and for a scenario with two Higgs doublets and an extra complex scalar singlet (2HDM+S). Values of the squared kinetic mixing coefficient $\varepsilon^2$ in the dark photon model above 10$^{-6}$ are excluded over most of the mass range of the search. In the 2HDM+S, values of the mixing angle $\sin(\theta_\text{H})$ above 0.08 are excluded over most of the mass range of the search with a fixed ratio of the Higgs doublets vacuum expectation $\tan\beta$ = 0.5

Search for dark matter particles in W+^+W−^- events with transverse momentum imbalance in proton-proton collisions at s\sqrt{s} = 13 TeV

International audienceA search for dark matter particles is performed using events with a pair of W bosons and large missing transverse momentum. Candidate events are selected by requiring one or two leptons ($\ell =$ electrons or muons). The analysis is based on proton-proton collision data collected at a center-of-mass energy of 13 TeV by the CMS experiment at the LHC and corresponding to an integrated luminosity of 138 fb$^{-1}$. No significant excess over the expected standard model background is observed in the $\ell\nu$qq and 2$\ell$2$\nu$ final states of the W$^+$W$^-$ boson pair. Limits are set on dark matter production in the context of a simplified dark Higgs model, with a dark Higgs boson mass above the W$^+$W$^-$ mass threshold. The dark matter phase space is probed in the mass range 100-300 GeV, extending the scope of previous searches. Current exclusion limits are improved in the range of dark Higgs masses from 160 to 250 GeV, for a dark matter mass of 200 GeV