39 research outputs found
Signature of the +jet and dijet production mediated by an excited quark with QCD next-to-leading order accuracy at the LHC
We present a detailed study of the production and decay of the excited quark
at the QCD next-to-leading order (NLO) level at the Large Hadron Collider,
using the narrow width approximation and helicity amplitudes method. We find
that the QCD NLO corrections can tighten the constraints on the model
parameters and reduce the scale dependencies of the total cross sections. We
discuss the signals of the excited quark production with decay mode
and , and present several
important kinematic distributions. Moreover, we give the upper limits of the
excited quark excluded mass range and the allowed parameter space for the
coupling constants and the excited quark mass.Comment: 20 pages, 13 figures; version published in PR
Transverse momentum resummation for color sextet and antitriplet scalar production at the LHC
We study the factorization and resummation of the transverse momentum
spectrum of the color sextet and antitriplet scalars produced at the LHC based
on soft-collinear effective theory. Compared to Z boson and Higgs production, a
soft function is required to account for the soft gluon emission from the
final-state colored scalar. The soft function is calculated at the
next-to-leading order, and the resummation is performed at the approximate
next-to-next-to-leading logarithmic accuracy. The non-perturbative effects and
PDF uncertainties are also discussed.Comment: 20 pages, 7 figure
Threshold resummation for the production of a color sextet (antitriplet) scalar at the LHC
We investigate threshold resummation effects in the production of a color
sextet (antitriplet) scalar at next-to-next-to-leading logarithmic (NNLL) order
at the LHC in the frame of soft-collinear effective theory. We show the total
cross section and the rapidity distribution with NLO+NNLL accuracy, and we
compare them with the NLO results. Besides, we use recent dijet data at the LHC
to give the constraints on the couplings between the colored scalars and
quarks.Comment: 21 pages,9 figures,3 tables; Version published in EPJ
Low-energy Scattering of System and the Resonance-like Structure
In this paper, low-energy scattering of the meson
system is studied within L\"uscher's finite-size formalism using
twisted mass gauge field configurations. With three different pion mass values,
the -wave threshold scattering parameters, namely the scattering length
and the effective range , are extracted in channel. Our
results indicate that, in this particular channel, the interaction between the
two vector charmed mesons is weakly repulsive in nature hence do not support
the possibility of a shallow bound state for the two mesons, at least for the
pion mass values being studied. This study provides some useful information on
the nature of the newly discovered resonance-like structure
observed in various experiments.Comment: 11 pages, 6 figures. arXiv admin note: substantial text overlap with
arXiv:1403.131
Signature of same-sign top pair production mediated by a nonuniversal with QCD next-to-leading accuracy at the LHC
We present a detailed study of the same-sign top pair production mediated by
a non-universal including production and decay at the Large Hadron
Collider (LHC) at the QCD next-to-leading order (NLO) level, using the narrow
width approximation and helicity amplitudes method. We find that the QCD NLO
corrections can loose the constraint on the model parameters and reduce the
dependence of the total cross sections on the factorization scale
significantly. We also study the signature and backgrounds of the process at
the NLO level. In order to suppress the backgrounds, we further investigate the
difference between the production rates of the positively and negatively
charged dilepton at the LHC, and find that the same-sign dilepton signal of the
new physics could be discovered more easily.Comment: 24 pages, 14 figures, 2 table. final version in PRD. arXiv admin
note: text overlap with arXiv:1103.512
A giant hemolymphangioma of the pancreas in a 20-year-old girl: a report of one case and review of the literature
<p>Abstract</p> <p>Background</p> <p>Hemolymphangioma of the pancreas is a very rare benign tumor. There were only six reports of this disease until December 2008. Herein, we report a case of giant hemolymphangioma of the pancreas in a 20-year-old girl.</p> <p>Case presentation</p> <p>We describe a 20-year-old girl who presented with a mass in abdominal cavity and epigastric discomfort about a week. Physical examination showed a great abdominal mass. Abdominal computed tomography showed extrinsic duodenal compression due to a large retroperitoneal tumor possibly arising from pancreas. The tumor enucleation was performed and a diagnosis of hemolymphangioma of the pancreas was made. The patient had a complication of chylous leakage, which was successfully managed. The patient is alive and well, after 26 months of follow-up, with no complaints or recurrence.</p> <p>Conclusion</p> <p>From this case and literature, we can conclude that hemolymphangioma of the pancreas in adult is a rare benign tumor, and accurate diagnosis can not be preoperatively established. Tumor resection should be performed whenever possible. The risk of recurrence seems very low.</p
Low-energy Scattering of System And the Resonance-like Structure
In this exploratory lattice study, low-energy scattering of the
meson system is analyzed using lattice QCD with
twisted mass fermion configurations with three pion mass values. The
calculation is performed within single-channel L\"uscher's finite-size
formalism. The threshold scattering parameters, namely the scattering length
and the effective range , for the -wave scattering in
channel are extracted. For the cases in our study, the interaction between the
two charmed mesons is weakly repulsive. Our lattice results therefore do not
support the possibility of a shallow bound state for the two mesons for the
pion mass values we studied. This calculation provides some useful information
on the nature of the newly discovered resonance-like structure by
various experimental groups.Comment: 14 pages, 6 figures. Version accepted by PR
The Effects of ATIR Blocker on the Severity of COVID-19 in Hypertensive Inpatients and Virulence of SARS-CoV-2 in Hypertensive hACE2 Transgenic Mice.
Angiotensin-converting enzyme 2 (ACE2) is required for the cellular entry of the severe acute respiratory syndrome coronavirus 2. ACE2, via the Ang-(1-7)-Mas-R axis, is part of the antihypertensive and cardioprotective effects of the renin-angiotensin system. We studied hospitalized COVID-19 patients with hypertension and hypertensive human(h) ACE2 transgenic mice to determine the outcome of COVID-19 with or without AT1 receptor (AT1R) blocker treatment. The severity of the illness and the levels of serum cardiac biomarkers (CK, CK-BM, cTnI), as well as the inflammation markers (IL-1, IL-6, CRP), were lesser in hypertensive COVID-19 patients treated with AT1R blockers than those treated with other antihypertensive drugs. Hypertensive hACE2 transgenic mice, pretreated with AT1R blocker, had increased ACE2 expression and SARS-CoV-2 in the kidney and heart, 1 day post-infection. We conclude that those hypertensive patients treated with AT1R blocker may be at higher risk for SARS-CoV-2 infection. However, AT1R blockers had no effect on the severity of the illness but instead may have protected COVID-19 patients from heart injury, via the ACE2-angiotensin1-7-Mas receptor axis. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12265-021-10147-3