489 research outputs found
{Measurement of the mixing parameters of neutral charm mesons and search for indirect \textit{\textbf{CP}} violation with \boldmath decays at LHCb
Mixing is the time-dependent phenomenon of a neutral meson (in this case charm meson ) changing into its anti-particle () and vice versa. This occurs because the mass eigenstates, denoted and are linear combinations of the flavour eigenstates and . Mixing is governed by two parameters and defined as: and where is the average decay width. CP-violation can occur in mixing or in the interference between mixing and decay. The CP-violation parameters and describe the superposition of the flavour eigenstates and the mass eigenstates: . The self-conjugate decay offers direct access to the mixing and CP-violation parameters through a time and phase-space dependent fit to the Dalitz variables and decay-time of this decay. This thesis reports a measurement of the mixing and \CP-violation parameters using data collected at the LHCb experiment in the Run 2 data-taking period in 2016-2018, corresponding to an integrated luminosity of 6~fb. This analysis uses mesons originating from semi-leptonic meson decays. The decay is modelled by expressing the three-body decay as the superposition of successive two-body decays through intermediate resonances. The blinded mixing parameters are found to be: \begin{equation*} \begin{split} x &= (x.xx \pm 0.86_{\text{stat}} \pm 0.39_{\text{syst}} \pm 0.24_{\text{model}})\times 10^{-3} \\ y &= (y.yy \pm 0.76_{\text{stat}} \pm 0.59_{\text{syst}} \pm 0.26_{\text{model}})\times 10^{-3} \end{split} \end{equation*} where the uncertainties are statistical, systematic and from the choice of amplitude model. The \CP-violation parameters are expressed in terms of and which are defined as the difference in mixing parameters measured for and : \begin{equation*} \begin{split} \Delta x &= (0.00 \pm 0.59) \times 10^{-3} \\ \Delta y &= (0.00 \pm 0.51) \times 10^{-3} \\ \end{split} \end{equation*} the uncertainties are currently statistical only and the results are blind
Experimental long-term diabetes mellitus alters the transcriptome and biomechanical properties of the rat urinary bladder
From Springer Nature via Jisc Publications RouterHistory: received 2020-09-28, accepted 2021-06-30, registration 2021-07-13, pub-electronic 2021-07-30, online 2021-07-30, collection 2021-12Publication status: PublishedFunder: Medical Research Council; doi: http://dx.doi.org/10.13039/501100000265; Grant(s): MR/L002744/1, MR/T016809/1, MR/L002744/1, MR/L002744/1Funder: Diabetes UK; doi: http://dx.doi.org/10.13039/501100000361; Grant(s): 15/0005283, 15/0005283Abstract: Diabetes mellitus (DM) is the leading cause of chronic kidney disease and diabetic nephropathy is widely studied. In contrast, the pathobiology of diabetic urinary bladder disease is less understood despite dysfunctional voiding being common in DM. We hypothesised that diabetic cystopathy has a characteristic molecular signature. We therefore studied bladders of hyperglycaemic and polyuric rats with streptozotocin (STZ)-induced DM. Sixteen weeks after induction of DM, as assessed by RNA arrays, wide-ranging changes of gene expression occurred in DM bladders over and above those induced in bladders of non-hyperglycaemic rats with sucrose-induced polyuria. The altered transcripts included those coding for extracellular matrix regulators and neural molecules. Changes in key genes deregulated in DM rat bladders were also detected in db/db mouse bladders. In DM rat bladders there was reduced birefringent collagen between detrusor muscle bundles, and atomic force microscopy showed a significant reduction in tissue stiffness; neither change was found in bladders of sucrose-treated rats. Thus, altered extracellular matrix with reduced tissue rigidity may contribute to voiding dysfunction in people with long-term DM. These results serve as an informative stepping stone towards understanding the complex pathobiology of diabetic cystopathy
The CCAT-Prime Submillimeter Observatory
The Cerro Chajnantor Atacama Telescope-prime (CCAT-prime) is a new 6-m,
off-axis, low-emissivity, large field-of-view submillimeter telescope scheduled
for first light in the last quarter of 2021. In summary, (a) CCAT-prime
uniquely combines a large field-of-view (up to 8-deg), low emissivity telescope
(< 2%) and excellent atmospheric transmission (5600-m site) to achieve
unprecedented survey capability in the submillimeter. (b) Over five years,
CCAT-prime first generation science will address the physics of star formation,
galaxy evolution, and galaxy cluster formation; probe the re-ionization of the
Universe; improve constraints on new particle species; and provide for improved
removal of dust foregrounds to aid the search for primordial gravitational
waves. (c) The Observatory is being built with non-federal funds (~ \$40M in
private and international investments). Public funding is needed for
instrumentation (~ \$8M) and operations (\$1-2M/yr). In return, the community
will be able to participate in survey planning and gain access to curated data
sets. (d) For second generation science, CCAT-prime will be uniquely positioned
to contribute high-frequency capabilities to the next generation of CMB surveys
in partnership with the CMB-S4 and/or the Simons Observatory projects or
revolutionize wide-field, sub-millimetter line intensity mapping surveys.Comment: Astro2020 APC White Pape
Burden of injury along the development spectrum : associations between the Socio-demographic Index and disability-adjusted life year estimates from the Global Burden of Disease Study 2017
Background The epidemiological transition of non-communicable diseases replacing infectious diseases as the main contributors to disease burden has been well documented in global health literature. Less focus, however, has been given to the relationship between sociodemographic changes and injury. The aim of this study was to examine the association between disability-adjusted life years (DALYs) from injury for 195 countries and territories at different levels along the development spectrum between 1990 and 2017 based on the Global Burden of Disease (GBD) 2017 estimates. Methods Injury mortality was estimated using the GBD mortality database, corrections for garbage coding and CODEm-the cause of death ensemble modelling tool. Morbidity estimation was based on surveys and inpatient and outpatient data sets for 30 cause-of-injury with 47 nature-of-injury categories each. The Socio-demographic Index (SDI) is a composite indicator that includes lagged income per capita, average educational attainment over age 15 years and total fertility rate. Results For many causes of injury, age-standardised DALY rates declined with increasing SDI, although road injury, interpersonal violence and self-harm did not follow this pattern. Particularly for self-harm opposing patterns were observed in regions with similar SDI levels. For road injuries, this effect was less pronounced. Conclusions The overall global pattern is that of declining injury burden with increasing SDI. However, not all injuries follow this pattern, which suggests multiple underlying mechanisms influencing injury DALYs. There is a need for a detailed understanding of these patterns to help to inform national and global efforts to address injury-related health outcomes across the development spectrum.Peer reviewe
New genetic loci link adipose and insulin biology to body fat distribution.
Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (PÂ <Â 5Â ĂÂ 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms
Physics case for an LHCb Upgrade II - Opportunities in flavour physics, and beyond, in the HL-LHC era
The LHCb Upgrade II will fully exploit the flavour-physics opportunities of the HL-LHC, and study additional physics topics that take advantage of the forward acceptance of the LHCb spectrometer. The LHCb Upgrade I will begin operation in 2020. Consolidation will occur, and modest enhancements of the Upgrade I detector will be installed, in Long Shutdown 3 of the LHC (2025) and these are discussed here. The main Upgrade II detector will be installed in long shutdown 4 of the LHC (2030) and will build on the strengths of the current LHCb experiment and the Upgrade I. It will operate at a luminosity up to 2Ă1034
cmâ2sâ1, ten times that of the Upgrade I detector. New detector components will improve the intrinsic performance of the experiment in certain key areas. An Expression Of Interest proposing Upgrade II was submitted in February 2017. The physics case for the Upgrade II is presented here in more depth. CP-violating phases will be measured with precisions unattainable at any other envisaged facility. The experiment will probe b â sl+lâand b â dl+lâ transitions in both muon and electron decays in modes not accessible at Upgrade I. Minimal flavour violation will be tested with a precision measurement of the ratio of B(B0 â ÎŒ+ÎŒâ)/B(Bs â ÎŒ+ÎŒâ). Probing charm CP violation at the 10â5 level may result in its long sought discovery. Major advances in hadron spectroscopy will be possible, which will be powerful probes of low energy QCD. Upgrade II potentially will have the highest sensitivity of all the LHC experiments on the Higgs to charm-quark couplings. Generically, the new physics mass scale probed, for fixed couplings, will almost double compared with the pre-HL-LHC era; this extended reach for flavour physics is similar to that which would be achieved by the HE-LHC proposal for the energy frontier
LHCb upgrade software and computing : technical design report
This document reports the Research and Development activities that are carried out in the software and computing domains in view of the upgrade of the LHCb experiment. The implementation of a full software trigger implies major changes in the core software framework, in the event data model, and in the reconstruction algorithms. The increase of the data volumes for both real and simulated datasets requires a corresponding scaling of the distributed computing infrastructure. An implementation plan in both domains is presented, together with a risk assessment analysis
Multidifferential study of identified charged hadron distributions in -tagged jets in proton-proton collisions at 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 boson. The charged-hadron distributions are studied longitudinally and
transversely to the jet direction for jets with transverse momentum 20 GeV and in the pseudorapidity range . 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. 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 decay
The decay is studied
in proton-proton collisions at a center-of-mass energy of TeV
using data corresponding to an integrated luminosity of 5
collected by the LHCb experiment. In the system, the
state observed at the BaBar and Belle experiments is
resolved into two narrower states, and ,
whose masses and widths are measured to be where the first uncertainties are statistical and the second
systematic. The results are consistent with a previous LHCb measurement using a
prompt sample. Evidence of a new
state is found with a local significance of , whose mass and width
are measured to be and , respectively. In addition, evidence of a new decay mode
is found with a significance of
. The relative branching fraction of with respect to the
decay is measured to be , 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
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