457 research outputs found
Dependence of calculated binding energies and widths of -mesic nuclei on treatment of subthreshold -nucleon interaction
We demonstrate that the binding energies and widths of eta-mesic nuclei
depend strongly on subthreshold eta-N interaction. This strong dependence is
made evident from comparing three different eta-nucleus optical potentials: (1)
a microscopic optical potential taking into account the full effects of
off-shell eta-nucleon interactions; (2) a factorization approximation to the
microscopic optical potential where a downward energy shift parameter is
introduced to approximate the subthreshold eta-nucleon interaction; and (3) an
optical potential using on-shell eta-nucleon scattering length as the
interaction input. Our analysis indicates that the in-medium N
interaction for bound-state formation is about 30 MeV below the free-space
N threshold, which causes a substantial reduction of the attractive force
between the and nucleon with respect to that implied by the scattering
length. Consequently, the scattering-length approach overpredicts the binding
energies and caution must be exercised when these latter predictions are used
as guide in searching for -nucleus bound states. We also show that
final-state-interaction analysis cannot provide an unequivocal determination of
the existence of -nucleus bound state. More direct measurements are,
therefore, necessary.Comment: 28 pages, 1 figur
The systematic study of the influence of neutron excess on the fusion cross sections using different proximity-type potentials
Using different types of proximity potentials, we have examined the trend of
variations of barrier characteristics (barrier height and its position) as well
as fusion cross sections for 50 isotopic systems including various collisions
of C, O, Mg, Si, S, Ca, Ar, Ti and Ni nuclei with condition
for compound systems. The results of our studies reveal that the relationships
between increase of barrier positions and decrease of barrier heights are both
linear with increase of ratio. Moreover, fusion cross sections also
enhance linearly with increase of this ratio.Comment: 28 pages, 7 figures, 5 Table
Impact of gaming disorder on first episode psychosis patients' evolution: Protocol for a multicentered prospective study.
The objective of this study is to underline the impact of Gaming Disorder on the clinical evolution of patients with First Episode Psychosis. The specific aims of the study are to determine the prevalence of gaming disorder among those patients and assess the consequences of gaming on their clinical trajectory.
This is a prospective multicenter cohort study that will enrol 800 patients diagnosed with a first episode psychosis, with a follow-up period of up to 3 years. Using a systematic screening procedure for gaming disorder, the clinical staff will assess patients gaming habits at admission and every 6 months thereafter. Information from patients' medical records will also be extracted using the same timeframe.
The patients' characteristics at admission and during follow-up will be presented in the form of descriptive statistics and compared between different subgroups of patients using uni- and multivariate logistic regression models. Repeated measures ANCOVA will also be performed to analyse the impact of gaming disorders on patients' clinical path as assessed by the Positive and Negative Syndrome Scale and the Clinical Global Impression scale, considering covariates such as psychiatric diagnosis, pharmacological treatment, age, sex/gender, and duration of untreated psychosis.
These findings will guide the development of prevention, detection, and treatment strategies for the comorbidity between gaming disorder and first episode psychosis, ultimately improving the patients' recovery
Positive specific heat of the quantum corrected dilaton black hole
Path integral quantization of dilaton gravity in two dimensions is applied to
the CGHS model to the first nontrivial order in matter loops. Our approach is
background independent as geometry is integrated out exactly. The result is an
effective shift of the Killing norm: the apparent horizon becomes smaller. The
Hawking temperature which is constant to leading order receives a quantum
correction. As a consequence, the specific heat becomes positive and
proportional to the square of the black hole mass.Comment: 18 pages, JHEP style, 1 eps figure, v2: extended the discussion,
added new formulas for mass change, added three new references (in particular
[35]
Invariant mass distributions for the pp to p p eta reaction at Q=10 MeV
Proton-proton and proton-eta invariant mass distributions and the total cross
section for the pp to pp eta reaction have been determined near the threshold
at an excess energy of Q=10 MeV. The experiment has been conducted using the
COSY-11 detector setup and the cooler synchrotron COSY. The determined
invariant mass spectra reveal significant enhancements in the region of low
proton-proton relative momenta, similarly as observed previously at higher
excess energies of Q=15.5 MeV and Q= 40MeV.Comment: 6 pages, 3 figures, submitted to Eur.Phys. J.
Search for composite and exotic fermions at LEP 2
A search for unstable heavy fermions with the DELPHI detector at LEP is
reported. Sequential and non-canonical leptons, as well as excited leptons and
quarks, are considered. The data analysed correspond to an integrated
luminosity of about 48 pb^{-1} at an e^+e^- centre-of-mass energy of 183 GeV
and about 20 pb^{-1} equally shared between the centre-of-mass energies of 172
GeV and 161 GeV. The search for pair-produced new leptons establishes 95%
confidence level mass limits in the region between 70 GeV/c^2 and 90 GeV/c^2,
depending on the channel. The search for singly produced excited leptons and
quarks establishes upper limits on the ratio of the coupling of the excited
fermio
Search for charginos in e+e- interactions at sqrt(s) = 189 GeV
An update of the searches for charginos and gravitinos is presented, based on
a data sample corresponding to the 158 pb^{-1} recorded by the DELPHI detector
in 1998, at a centre-of-mass energy of 189 GeV. No evidence for a signal was
found. The lower mass limits are 4-5 GeV/c^2 higher than those obtained at a
centre-of-mass energy of 183 GeV. The (\mu,M_2) MSSM domain excluded by
combining the chargino searches with neutralino searches at the Z resonance
implies a limit on the mass of the lightest neutralino which, for a heavy
sneutrino, is constrained to be above 31.0 GeV/c^2 for tan(beta) \geq 1.Comment: 22 pages, 8 figure
Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment
This paper describes an analysis of the angular distribution of W->enu and
W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with
the ATLAS detector at the LHC in 2010, corresponding to an integrated
luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and
the missing transverse energy, the W decay angular distribution projected onto
the transverse plane is obtained and analysed in terms of helicity fractions
f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV
and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw
> 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour,
are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017
+/- 0.030, where the first uncertainties are statistical, and the second
include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables,
revised author list, matches European Journal of Physics C versio
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