1,348 research outputs found
Spectra of Heavy Quarkonia in a Magnetized-Hot Medium in the Framework of Fractional Non-relativistic Quark Model
In the fractional nonrelativistic potential model, the decomposition of heavy
quarkonium in a hot magnetized medium is investigated. The analytical solution
of the fractional radial Schrodinger equation for the hot-magnetized
interaction potential is displayed by using the conformable fractional
Nikiforov-Uvarov method. Analytical expressions for the energy eigenvalues and
the radial wave function are obtained for arbitrary quantum numbers. Next, we
study the charmonium and bottmonium binding energies for different magnetic
field values in the thermal medium. The effect of the fractional parameter on
the decomposition temperature is also analyzed for charmonium and bottomonium
in the presence of hot magnetized media. We conclude that the dissociation of
heavy quarkonium in the fractional nonrelativistic potential model is more
practical than the classical nonrelativistic potential model.Comment: 13 pages, 4 figures. arXiv admin note: substantial text overlap with
arXiv:2104.0054
A meta-analysis for the effect of prophylactic GTN on the incidence of post-ERCP pancreatitis and on the successful rate of cannulation of bile ducts
<p>Abstract</p> <p>Background</p> <p>Glyceryl trinitrate (GTN) has been shown to be able to relax the sphincter of Oddi (SO) both in animals and humans. Theoretically, the use of these compounds during and after endoscopic retrograde cholangiopancreatgraphy (ERCP) could relax the biliary and pancreatic sphincters, facilitating cannulation of common bile duct (CBD) during the procedure, or minimizing potential pancreatic outflow obstruction after the procedure. However, clinical trials evaluating the protective effect of GTN on the post-endoscopic retrograde cholangiopancreatgraphy pancreatitis (PEP) have yielded inconclusive results. This meta-analysis is to systematically assess the effect of prophylactic administration of glyceryl trinitrate (GTN) on the prevention of PEP and the effect on the cannulation of bile ducts.</p> <p>Methods</p> <p>By searching PubMed (1966 to September 2009), CENTRAL (Cochrane Controlled trials Register; issue 3, 2009) and EMBASE.com (1984 to September 2009), two independent reviewers systematically identified prospective randomized controlled trials (RCTs) detecting the effect of prophylactic GTN on the incidence of PEP and on the cannulation of bile ducts. A meta-analysis of these clinical trials was then performed.</p> <p>Results</p> <p>There are 55/899(6.1%) patients suffering PEP in the treatment group versus 95/915(10.4%) patients in the placebo group. The overall pooled risk of PEP was significantly lower in the GTN group than in the placebo group (OR 0.56, 95% CI: 0.40 to 0.79, p = 0.001). Subgroup analyses suggested that GTN administered by the sublingual form (OR 0.34,95% CI:0.16 to 0.75, p = 0.007) is more effective than transdermal route(OR 0.64,95% CI:0.40 to 1.01, p = 0.05), and the protective effect of GTN was far more obvious in the centers with high incidence of PEP (OR 0.40, 95% CI:0.24 to 0.67, p = 0.0006) than those centers with a low incidence of PEP (OR 0.75, 95% CI: 0.47 to 1.20, p = 0.22). Additionally, the meta-analysis suggests that GTN was not helpful for the cannulation of bile ducts.</p> <p>Conclusion</p> <p>We concluded that prophylactic administration of GTN may significantly reduce the incidence of PEP and not be helpful for the cannulation of bile ducts.</p
Behavioral risk factors and clinical course of cardiovascular diseases and other noncommunicable diseases during quarantine in various regions of Russia
Aim. To assess the behavioral risk factors and the clinical course of cardiovascular diseases (CVDs) and other noncommunicable diseases (NCDs) during quarantine in various regions of Russia.Material and methods. This multicenter cohort cross-sectional study included 205 men and women from 6 Russian cities. Further, 4 of them (Saransk, Nizhny Novgorod, Penza, Ulyanovsk) were combined into one group â the Volga region. The study included men and women aged 30-69 years with one or more NCDs (hypertension, coronary artery disease with or without myocardial infarction, type 2 diabetes, chronic obstructive pulmonary disease/asthma and cancer in patients receiving chemotherapy and/or radiation therapy) who were self-isolated during coronavirus disease 2019 (COVID-19) pandemic. For all patients, a questionnaire was used, which included socio-demographic parameters, behavioral risk factors, status of the underlying disease, incidence of COVID-19 and its complications. Self-assessment of the state of health was carried out using the European Quality of Life Questionnaire.Results. In every third Muscovite, the intensity of physical activity decreased, and in the groups of patients from Omsk and the Volga region, it was 45% and 43%, respectively. An increase in meal frequency and an impairment of eating habits in Moscow and Omsk was noted in 18,2% and 18,7% of participants, while in Volga region subjects, these parameters were 2 times higher (42,4%). At the same time, no significant changes of alcohol consumption and smoking was revealed in the cohorts. Hypertensive crises during a pandemic were noted in all three subgroups, but more of them were recorded in the Volga region â in every third patient (p< 0,05 compared to Moscow), in the Omsk group â in every fourth patient, and among Muscovites â no more than 5%. Clinical deterioration in patients with angina was noted in 15% of cases, while the smallest number was noted in Omsk subjects (5,3%), three times less than in other subgroups. Changes in intensity and regimen of hypoglycemic therapy were noted in patients from Omsk, while 30% of them (p< 0,05 compared with the Volga region) increased the doses of medications taken. Chronic obstructive pulmonary disease was registered in the group with the largest number of Volga region patients â 14,1% (p< 0,05 compared to Omsk), while 17% of patients in this group increased the dose of drugs. Any cancer was recorded in 13,6% of Muscovites, while in the other two groups â about 5%. The largest number of patients from the Volga region noted a health decline over the past year (30,8%), while every fifth patient from Omsk (19,6%) and 13,6% of Muscovites reported health changes.Conclusion. During quarantine and self-isolation, changes in dietary habits and physical activity decline were noted among patients with NCDs, while alcohol consumption and smoking remained practically unchanged. The change in clinical status was characterized by an increase in hypertensive crisis incidence, an increase in doses of antihypertensive and hypoglycemic medication. Depending on the region, the health decline was noted by 13-31% of patients with NCDs
Observation of two new baryon resonances
Two structures are observed close to the kinematic threshold in the mass spectrum in a sample of proton-proton collision data, corresponding
to an integrated luminosity of 3.0 fb recorded by the LHCb experiment.
In the quark model, two baryonic resonances with quark content are
expected in this mass region: the spin-parity and
states, denoted and .
Interpreting the structures as these resonances, we measure the mass
differences and the width of the heavier state to be
MeV,
MeV,
MeV, where the first and second
uncertainties are statistical and systematic, respectively. The width of the
lighter state is consistent with zero, and we place an upper limit of
MeV at 95% confidence level. Relative
production rates of these states are also reported.Comment: 17 pages, 2 figure
Measurement of the mass and lifetime of the baryon
A proton-proton collision data sample, corresponding to an integrated
luminosity of 3 fb collected by LHCb at and 8 TeV, is used
to reconstruct , decays. Using the , decay mode for calibration, the lifetime ratio and absolute
lifetime of the baryon are measured to be \begin{align*}
\frac{\tau_{\Omega_b^-}}{\tau_{\Xi_b^-}} &= 1.11\pm0.16\pm0.03, \\
\tau_{\Omega_b^-} &= 1.78\pm0.26\pm0.05\pm0.06~{\rm ps}, \end{align*} where the
uncertainties are statistical, systematic and from the calibration mode (for
only). A measurement is also made of the mass difference,
, and the corresponding mass, which
yields \begin{align*} m_{\Omega_b^-}-m_{\Xi_b^-} &= 247.4\pm3.2\pm0.5~{\rm
MeV}/c^2, \\ m_{\Omega_b^-} &= 6045.1\pm3.2\pm 0.5\pm0.6~{\rm MeV}/c^2.
\end{align*} These results are consistent with previous measurements.Comment: 11 pages, 5 figures, All figures and tables, along with any
supplementary material and additional information, are available at
https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2016-008.htm
Observation of associated production of a boson with a meson in the~forward region
A search for associated production of a boson with an open charm meson is
presented using a data sample, corresponding to an integrated luminosity of
of proton--proton collisions at a centre-of-mass energy
of 7\,TeV, collected by the LHCb experiment. %% Seven candidate events for
associated production of a boson with a meson and four candidate
events for a boson with a meson are observed with a combined
significance of 5.1standard deviations. The production cross-sections in the
forward region are measured to be where the first uncertainty is statistical and the
second systematic.Comment: 18 pages, 2 figure
Measurement of the lifetime
Using a data set corresponding to an integrated luminosity of ,
collected by the LHCb experiment in collisions at centre-of-mass energies
of 7 and 8 TeV, the effective lifetime in the
decay mode, , is measured to be ps. Assuming
conservation, corresponds to the lifetime of the light
mass eigenstate. This is the first measurement of the effective
lifetime in this decay mode.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2016-017.htm
Bose-Einstein correlations of same-sign charged pions in the forward region in pp collisions at âs=7 TeV
Bose-Einstein correlations of same-sign charged pions, produced in protonproton collisions at a 7 TeV centre-of-mass energy, are studied using a data sample collected
by the LHCb experiment. The signature for Bose-Einstein correlations is observed in the
form of an enhancement of pairs of like-sign charged pions with small four-momentum
difference squared. The charged-particle multiplicity dependence of the Bose-Einstein correlation parameters describing the correlation strength and the size of the emitting source
is investigated, determining both the correlation radius and the chaoticity parameter. The
measured correlation radius is found to increase as a function of increasing charged-particle
multiplicity, while the chaoticity parameter is seen to decreas
Measurements of the , , meson and baryon lifetimes
Measurements of -hadron lifetimes are reported using collision data,
corresponding to an integrated luminosity of 1.0fb, collected by the
LHCb detector at a centre-of-mass energy of Tev. Using the exclusive decays
, , ,
and the average decay
times in these modes are measured to be = 0.004 0.003 ps, =
0.006 0.004 ps, = 0.013
0.005 ps, = 0.027
0.006 ps and = 0.011
0.005 ps, where the first uncertainty is statistical and the second is
systematic. These represent the most precise lifetime measurements in these
decay modes. In addition, ratios of these lifetimes, and the ratio of the
decay-width difference, , to the average width, , in
the system, , are
reported. All quantities are found to be consistent with Standard Model
expectations.Comment: 28 pages, 4 figures. Updated reference
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