3,044,815 research outputs found
Spectroscopy of doubly charmed baryons: and
Using the quark-diquark approximation in the framework of Buchm\" uller-Tye
potential model, we investigate the spectroscopy of doubly charmed baryons:
and . Our results include the masses, parameters
of radial wave functions of states with the different excitations of both
diquark and light quark-diquark system. We calculate the values of fine and
hyperfine splittings of these levels and discuss some new features, connected
to the identity of heavy quarks, in the dynamics of hadronic and radiative
transitions between the states of these baryons.Comment: 10 pages, Latex file, 1 fig, corrected some typo
Radiative decays of the doubly charmed baryons in chiral perturbation theory
We have systematically investigated the spin- to
spin- doubly charmed baryon transition magnetic moments to the
next-to-next-to-leading order in the heavy baryon chiral perturbation theory
(HBChPT). Numerical results of transition magnetic moments and decay widths are
presented to the next-to-leading order:
,
,
,
keV,
keV,
keV.Comment: arXiv admin note: text overlap with arXiv:1707.02765,
arXiv:1706.0645
A note on a problem in communication complexity
In this note, we prove a version of Tarui's Theorem in communication
complexity, namely . Consequently, every
measure for leads to a measure for , subsuming a result of
Linial and Shraibman that problems with high mc-rigidity lie outside the
polynomial hierarchy. By slightly changing the definition of mc-rigidity
(arbitrary instead of uniform distribution), it is then evident that the class
of problems with low mc-rigidity equals . As , this rules out the possibility, that had been
left open, that even polynomial space is contained in
Chondrocalcinosis is common in the absence of knee involvement
Introduction:
We aimed to describe the distribution of radiographic chondrocalcinosis (CC) and to examine whether metacarpophalangeal joint (MCPJ) calcification and CC at other joints occurs in the absence of knee involvement.
Methods:
This was a cross-sectional study embedded in the Genetics of Osteoarthritis and Lifestyle study (GOAL). All participants (n = 3,170) had radiographs of the knees, hands, and pelvis. These were scored for radiographic changes of osteoarthritis (OA), for CC at knees, hips, symphysis pubis, and wrists, and for MCPJ calcification. The prevalence of MCPJ calcification and CC overall, at each joint, and in the presence or absence of knee involvement, was calculated.
Results:
The knee was the commonest site of CC, followed by wrists, hips, and symphysis pubis. CC was more likely to be bilateral at knees and wrists but unilateral at hips. MCPJ calcification was usually bilateral, and less common than CC at knees, hips, wrists, and symphysis pubis. Unlike that previously reported, CC commonly occurred without any knee involvement; 44.4% of wrist CC, 45.9% of hip CC, 45.5% of symphysis pubis CC, and 31.3% of MCPJ calcification occurred in patients without knee CC. Those with meniscal or hyaline articular cartilage CC had comparable ages (P = 0.21), and neither preferentially associated with fibrocartilage CC at distant joints.
Conclusions:
CC visualized on a plain radiograph commonly occurs at other joints in the absence of radiographic knee CC. Therefore, knee radiographs alone are an insufficient screening test for CC. This has significant implications for clinical practice, for epidemiologic and genetic studies of CC, and for the definition of OA patients with coexistent crystal deposition
Estimate of the Hadronic Production of the Doubly Charmed Baryon under GM-VFN Scheme
Hadronic production of the doubly charmed baryon (
and ) is investigated under the general-mass
variable-flavor-number (GM-VFN) scheme. The gluon-gluon fusion mechanism and
the intrinsic charm mechanisms, i.e. via the sub-processes
,
; ,
and , , are taken into account in the investigation, where
(in color {\bf }) and (in color
{\bf 6}) are two possible -wave configurations of the doubly charmed diquark
pair inside the baryon . Numerical results for the production
at hadornic colliders LHC and TEVATRON show that both the contributions from
the doubly charmed diquark pairs and are
sizable with the assumption that the two NRQCD matrix elements are equal, and
the total contributions from the `intrinsic' charm mechanisms are bigger than
those of the gluon-gluon fusion mechanism. For the production in the region of
small transverse-momentum , the intrinsic mechanisms are dominant over the
gluon-gluon fusion mechanism and they can raise the theoretical prediction of
the by almost one order.Comment: 26 pages, 8 figure
Solution to the Cosmological Constant Problem in a Regge Quantum Gravity Model
We show that it is possible to solve the cosmological constant (CC) problem
in a discrete quantum gravity theory based on Regge calculus by using the
effective action approach and a special path-integral measure. The effective
cosmological constant is given as a sum of 3 terms: the classical CC, the
quantum gravity CC and the matter CC. Since the observations can only measure
the sum of these 3 terms, we can choose the classical CC to be equal to the
negative value of the matter CC. Hence the effective CC is given only by the
quantum gravity CC, which is determined by the path-integral measure. Since the
path-integral measure depends on a free parameter, this parameter can be chosen
such that the effective CC gives the observed value.Comment: v4: published version. arXiv admin note: substantial text overlap
with arXiv:1407.112
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