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

GENERALIZATION OF POSTURE TRAINING TO COMPUTER WORKSTATIONS IN AN APPLIED SETTING

Improving employees' posture may decrease the risk of musculoskeletal disorders. The current paper is a systematic replication and extension of Sigurdsson and Austin (2008), who found that an intervention consisting of information, real-time feedback, and self-monitoring improved participant posture at mock workstations. In the current study, participants worked in an applied setting, and posture data were collected at participants' own workstations and a mock workstation. Intervention in the mock setting was associated with consistent improvement in safe posture at the mock workstation, but generalization to the actual workstation was limited

MODIFICATION OF PERSEVERATIVE RESPONDING THAT INCREASED EARNINGS BUT IMPEDED SKILL ACQUISITION IN A JOB-SKILLS TRAINING PROGRAM

Adults in a therapeutic workplace working on a computerized keyboarding training program earned vouchers for typing correct characters. Typing technique was evaluated on review steps. Participants could pass the review and earn a bonus, or skip the review and proceed with no bonus. Alternatively, participants could continue practicing on the same step. Participants persistently repeated the same step, which halted progress through the program but allowed them to increase their rate of responding and, as a result, their earnings. Blocking the initiation of practice on review steps and removing payment for practice initiated after prompts (extinction) both produced rapid progress through the program. These results underscore the importance of careful arrangement of the contingencies in adult education programs

A population-based record linkage study of mortality in hepatitis C-diagnosed persons with or without HIV coinfection in Scotland

Infection with the hepatitis C virus (HCV) is known to increase the risk of death from severe liver disease and, becauseHCVstatus is strongly associated with a history of injecting drug use, the effect of a key disease progression cofactor, infection with human immunodeficiency virus (HIV), is of interest. We examined allcause, liver-related and drug-related mortality and excess risk of death from these causes in a large cohort of HCV-monoinfected and HIV-coinfected persons in Scotland. The study population consisted of 20,163 persons confirmed to be infected with hepatitis C through laboratory testing in Scotland between 1991 and 2005. Records with sufficient identifiers were linked to the General Register Office for Scotland death register to retrieve associated mortality data, and were further linked to a national database of HIV-positive individuals to determine coinfection status. A total of 1715 HCV monoinfected and 305 HIV coinfected persons died of any cause during the follow-up period (mean of 5.4 and 6.4 years, respectively). Significant excess mortality was observed in both HCV monoinfected and HIV coinfected populations from liverrelated underlying causes (standardised mortality ratios of 25, 95% CI=23-27; and 37, 95% CI=26-52 for the two groups, respectively) and drug-related causes (25, 95% CI=23-27; 39, 95% CI=28-53. The risk of death from hepatocellular carcinoma, alcoholic or non-alcoholic liver disease, or from a drug-related cause, was greatly increased compared with the general Scottish population, with the highest standardised mortality ratio observed for hepatocellular carcinoma in the monoinfected group (70, 95% CI=57-85). This study has revealed considerable excess mortality from liver- and drug-related causes in the Scottish HCV-diagnosed population; these data are crucial to inform on the clinical management, and projected future public health burden, of HCV infection