908 research outputs found

    Model-independent constraints on the CKM matrix elements Vtb|V_{tb}|, Vts|V_{ts}| and Vtd|V_{td}|

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    Single top quark production cross sections at hadron colliders are traditionally used to extract the modulus of the VtbV_{tb} element of the Cabibbo-Kobayashi-Maskawa matrix under the following assumption: VtbVtd,Vts|V_{tb}| \gg |V_{td}|, |V_{ts}|. For the first time, direct limits on Vtd|V_{td}| and Vts|V_{ts}| are obtained using experimental data without the assumption of the unitarity of the CKM matrix. Limits on the Vtd|V_{td}|, Vts|V_{ts}| and Vtb|V_{tb}| are extracted from differential measurements of single top quark cross sections in tt-channel as a function of the rapidity and transverse momentum of the top quark and the light jet recoiling against the top quark. We have shown that the pseudorapidity of the forward jet in the single top production is one of the most powerful observables for discriminating between the Vtd|V_{td}| and Vtb|V_{tb}| events. We perform a global fit of top quark related CKM elements to experimental data from the LHC Runs I and II and Tevatron. Experimental data include inclusive and differential single top cross sections in tt-channel, inclusive tW production cross section, and top quark branching ratio to b quark and W boson. We present bounds on Vtb|V_{tb}|, Vts|V_{ts}| and Vtd|V_{td}| using current data and project the results for future LHC data sets corresponding to luminosities of 300 and 3000 \fb

    Effects of Personalized Aerobic-Exercise and Resistance-Training Prescriptions on College Students with Anxiety During the COVID-19

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    The COVID-19 pandemic has seriously increased anxiety prevalence among the public, including Chinese college students. However, many exercises cannot be performed as usual under the stay-at-home order. The purpose of this study was to evaluate and compare the effect of personalized individual aerobic-exercise and resistance-training prescriptions on anxiety in college students during the COVID-19. This was a 12-week three-arm randomized control trial using the intention-to-treat principle. Sixty-six college students with anxiety were recruited and randomized into aerobic-exercise (AE), resistance-training (RT), and health-education group (HE). AE and RT groups also received health education. Measures on anxiety and physical activity included Zung Self-Rating Anxiety Scale (SAS), Chinese College Students Mental Health Scale - Anxiety Subscale (CCSMHS-AS) and International Physical Activity Questionnaire-Short Form (IPAQ-SF). All data were collected at the baseline, 4, 8, 12 weeks and 4-week post-intervention. All participants completed the intervention and measurements. The mean (SD) of SAS, CCSMHS-AS score and physical activity was 56.36 (5.63), 19.27 (4.56), 1306.57 (1421.19) (met-min/week). After the intervention, 78.79% of anxiety participants improved from anxiety to “normal”. Participants in all groups showed a statistically and clinically significant improvement after 12-week intervention (p \u3c 0.001). Moreover, such improvement was well-maintained in RT and HE group as there were no significant differences in SAS and CCSMHS-AS at 4-week post-intervention compared to 12 weeks (p \u3e 0.05). However, the SAS score of participants in AE group showed a significant increase during the 4 weeks after intervention (p \u3c 0.05). No significant differences were observed in the effect of AE and RT on anxiety at each time-point (p \u3e 0.05). PA of participants in AE and RT group represented a significant improvement at 4-week post-intervention compared to baseline (p \u3c 0.01). Personalized individual aerobic-exercise and resistance-training combined with health-education resulted in a similar effect on reducing anxiety and improving physical activity, and the effect was better than health education alone. Furthermore, the effect of resistance-training and health-education on reducing anxiety was more stable than that of aerobic-exercise. We recommended 45- to 60-minute home-based individual exercise (including 30- to 40-minute main exercise) with progressive moderate-to-high intensity, 3 times/week for at least 12 weeks for those students with anxiety during the COVID-19 pandemic

    Electronic specific heat and low energy quasiparticle excitations in superconducting state of La2xSrxCuO4La_{2-x}Sr_xCuO_4 single crystals

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    Low temperature specific heat has been measured and extensively analyzed on a series of La2xSrxCuO4La_{2-x}Sr_xCuO_4 single crystals from underdoped to overdoped regime. From these data the quasiparticle density of states (DOS) in the mixed state is derived and compared to the predicted scaling law Cvol/TH=f(T/H)C_{vol}/T\sqrt{H}=f(T/\sqrt{H}) of d-wave superconductivity. It is found that the scaling law can be nicely followed by the optimally doped sample (x=0.15) in quite wide region of (T/H8K/TT/\sqrt{H} \leq 8 K /\sqrt{T}). However, the region for this scaling becomes smaller and smaller towards more underdoped region: a clear trend can be seen for samples from x=0.15 to 0.069. Therefore, generally speaking, the scaling quality becomes worse on the underdoped samples in terms of scalable region of T/HT/\sqrt{H}. This feature in the underdoped region is explained as due to the low energy excitations from a second order (for example, anti-ferromagnetic correlation, d-density wave, spin density wave or charge density wave order) that may co-exist or compete with superconductivity. Surprisingly, deviations from the d-wave scaling law have also been found for the overdoped sample (x=0.22). While the scaling law is reconciled for the overdoped sample when the core size effect is taken into account. An important discovery of present work is that the zero-temperature data follow the Volovik's relation Δγ(T=0)=AH\Delta \gamma(T=0)=A\sqrt{H} quite well for all samples investigated here although the applicability of the d-wave scaling law to the data at finite temperatures varies with doped hole concentration. Finally we present the doping dependence of some parameters, such as, the residual linear term γ0\gamma_0, the α\alpha value, etc. ...Comment: 15 pages, 24 figure

    GENERAL ACTEOSIDE OF REHMANNIAE LEAVES IN THE TREATMENT OF PRIMARY CHRONIC GLOMERULONEPHRITIS: A RANDOMIZED CONTROLLED TRIAL

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    The prospective, randomised, parallel controlled trial aimed to assess the efficacy and safety of Traditional Chinese Medicine – general acteoside of Rehmanniae leaves compared with piperazine ferulate in the treatment of primary chronic glomerulonephritis. A total of 400 patients diagnosed with primary chronic glomerulonephritis were recruited from outpatient clinics and were randomly assigned to the treatment group (general acteoside of Rehmanniae leaves, two 200mg tablets, bid) or the control group (piperazine ferulate, four 50-mg tablets, bid ). The primary outcome was 24-h urinary protein. Secondary outcome measures included evaluated glomerular filtration rate (eGFR), erythrocyturia, and electrolytes. After 8 weeks of treatment, the treatment group and the control group showed a mean reduction in 24-h proteinuria of 34.81% and 37.66%. The 95% CI of difference of the mean reduction in 24-h proteinuria between the two groups was [-11.50%, 5.80%]. No significant differences were found between the two groups in the erythrocyturia reduction. Neither group showed obvious changes between baseline and 8 weeks in eGFR or electrolytes. Adverse events occurred at a similarly low rate in the treatment group (1.5%) and control group (2.5%, P = 0.7238). Both general acteoside of of primary chronic glomerulonephritis

    GENERAL ACTEOSIDE OF REHMANNIAE LEAVES IN THE TREATMENT OF PRIMARY CHRONIC GLOMERULONEPHRITIS: A RANDOMIZED CONTROLLED TRIAL

    Get PDF
    The prospective, randomised, parallel controlled trial aimed to assess the efficacy and safety of Traditional Chinese Medicine – general acteoside of Rehmanniae leaves compared with piperazine ferulate in the treatment of primary chronic glomerulonephritis. A total of 400 patients diagnosed with primary chronic glomerulonephritis were recruited from outpatient clinics and were randomly assigned to the treatment group (general acteoside of Rehmanniae leaves, two 200mg tablets, bid) or the control group (piperazine ferulate, four 50-mg tablets, bid ). The primary outcome was 24-h urinary protein. Secondary outcome measures included evaluated glomerular filtration rate (eGFR), erythrocyturia, and electrolytes. After 8 weeks of treatment, the treatment group and the control group showed a mean reduction in 24-h proteinuria of 34.81% and 37.66%. The 95% CI of difference of the mean reduction in 24-h proteinuria between the two groups was [-11.50%, 5.80%]. No significant differences were found between the two groups in the erythrocyturia reduction. Neither group showed obvious changes between baseline and 8 weeks in eGFR or electrolytes. Adverse events occurred at a similarly low rate in the treatment group (1.5%) and control group (2.5%, P = 0.7238). Both general acteoside of of primary chronic glomerulonephritis

    Measurement of differential cross sections for top quark pair production using the lepton plus jets final state in proton-proton collisions at 13 TeV

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    National Science Foundation (U.S.

    Particle-flow reconstruction and global event description with the CMS detector

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    The CMS apparatus was identified, a few years before the start of the LHC operation at CERN, to feature properties well suited to particle-flow (PF) reconstruction: a highly-segmented tracker, a fine-grained electromagnetic calorimeter, a hermetic hadron calorimeter, a strong magnetic field, and an excellent muon spectrometer. A fully-fledged PF reconstruction algorithm tuned to the CMS detector was therefore developed and has been consistently used in physics analyses for the first time at a hadron collider. For each collision, the comprehensive list of final-state particles identified and reconstructed by the algorithm provides a global event description that leads to unprecedented CMS performance for jet and hadronic tau decay reconstruction, missing transverse momentum determination, and electron and muon identification. This approach also allows particles from pileup interactions to be identified and enables efficient pileup mitigation methods. The data collected by CMS at a centre-of-mass energy of 8 TeV show excellent agreement with the simulation and confirm the superior PF performance at least up to an average of 20 pileup interactions

    Identification of heavy-flavour jets with the CMS detector in pp collisions at 13 TeV

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    Many measurements and searches for physics beyond the standard model at the LHC rely on the efficient identification of heavy-flavour jets, i.e. jets originating from bottom or charm quarks. In this paper, the discriminating variables and the algorithms used for heavy-flavour jet identification during the first years of operation of the CMS experiment in proton-proton collisions at a centre-of-mass energy of 13 TeV, are presented. Heavy-flavour jet identification algorithms have been improved compared to those used previously at centre-of-mass energies of 7 and 8 TeV. For jets with transverse momenta in the range expected in simulated tt\mathrm{t}\overline{\mathrm{t}} events, these new developments result in an efficiency of 68% for the correct identification of a b jet for a probability of 1% of misidentifying a light-flavour jet. The improvement in relative efficiency at this misidentification probability is about 15%, compared to previous CMS algorithms. In addition, for the first time algorithms have been developed to identify jets containing two b hadrons in Lorentz-boosted event topologies, as well as to tag c jets. The large data sample recorded in 2016 at a centre-of-mass energy of 13 TeV has also allowed the development of new methods to measure the efficiency and misidentification probability of heavy-flavour jet identification algorithms. The heavy-flavour jet identification efficiency is measured with a precision of a few per cent at moderate jet transverse momenta (between 30 and 300 GeV) and about 5% at the highest jet transverse momenta (between 500 and 1000 GeV)

    Search for heavy resonances decaying to a top quark and a bottom quark in the lepton+jets final state in proton–proton collisions at 13 TeV

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