20,064 research outputs found
Electromagnetic Moments of the Baryon Decuplet
We compute the leading contributions to the magnetic dipole and electric
quadrupole moments of the baryon decuplet in chiral perturbation theory. The
measured value for the magnetic moment of the is used to determine
the local counterterm for the magnetic moments. We compare the chiral
perturbation theory predictions for the magnetic moments of the decuplet with
those of the baryon octet and find reasonable agreement with the predictions of
the large-- limit of QCD. The leading contribution to the quadrupole
moment of the and other members of the decuplet comes from one--loop
graphs. The pionic contribution is shown to be proportional to (and so
will not contribute to the quadrupole moment of nuclei), while the
contribution from kaons has both isovector and isoscalar components. The chiral
logarithmic enhancement of both pion and kaon loops has a coefficient that
vanishes in the limit. The third allowed moment, the magnetic octupole,
is shown to be dominated by a local counterterm with corrections arising at two
loops. We briefly mention the strange counterparts of these moments.Comment: Uses harvmac.tex, 15 pages with 3 PostScript figures packed using
uufiles. UCSD/PTH 93-22, QUSTH-93-05, Duke-TH-93-5
Baryons with Two Heavy Quarks as Solitons
Using the chiral soliton model and heavy quark symmetry we study baryons
containing two heavy quarks. If there exists a stable (under strong
interactions) meson consisting of two heavy quarks and two light ones, then we
find that there always exists a state of this meson bound to a chiral soliton
and to a chiral anti-soliton, corresponding to a two heavy quark baryon and a
baryon containing two heavy anti-quarks and five light quarks, or a
``heptaquark".Comment: 7 pages and 2 postscript figures appended, LaTex, UCI-TR 94-3
Measurement of the half-life of 198Au in a non-metal: High-precision measurement shows no host-material dependence
We have measured the half-life of the beta decay of 198Au to be 2.6948(9) d,
with the nuclide sited in an insulating environment. Comparing this result with
the half-life we measured previously with a metallic environment, we find the
half-lives in both environments to be the same within 0.04%, thus contradicting
a prediction that screening from a "plasma" of quasi-free electrons in a metal
increases the half-life by as much as 7%
1/N_c Expansion of the Heavy Baryon Isgur-Wise Functions
The 1/N_c expansion of the heavy baryon Isgur-Wise functions is discussed.
Because of the contracted SU(2N_f) light quark spin-flavor symmetry, the
universality relations among the Isgur-Wise functions of \Lambda_b to \Lambda_c
and \Sigma_b^{(*)} to \Sigma_c^{(*)} are valid up to the order of 1/N_c^2.Comment: 7 pages, latex, no figures, to appear in Phys. Rev.
Height and Body Mass on the Mating Market: Associations With Number of Sex Partners and Extra-Pair Sex Among Heterosexual Men and Women Aged 18â65
People with traits that are attractive on the mating market are better able to pursue their preferred mating strategy. Men who are relatively tall may be preferred by women because taller height is a cue to dominance, social status, access to resources, and heritable fitness, leading them to have more mating opportunities and sex partners. We examined height, education, age, ethnicity, and body mass index (BMI) as predictors of sexual history among heterosexual men and women (N = 60,058). The linear and curvilinear associations between self-reported height and sex partner number were small for men when controlling for education, BMI, and ethnicity (linear ÎČ = .05; curvilinear ÎČ = â.03). The mean and median number of sex partners for men of different heights were: very short (9.4; 5), short (11.0; 7), average (11.7; 7), tall (12.0; 7), very tall (12.1; 7), and extremely tall (12.3; 7). Men who were âoverweightâ reported a higher mean and median number of sex partners than men with other body masses. The results for men suggested limited variation in reported sex partner number across most of the height continuum, but that very short men report fewer partners than other men
Developmental and Cultural Perspectives on Childrenâs Postoperative Pain Management at Home
Outpatient surgery is extremely common in children, and approximately 4 million children experience significant pain after surgery in the USA each year. Management of children\u27s postoperative pain in the home setting is suboptimal and is impacted by characteristics of children and parents, as well as the larger family and cultural context. In particular, developmental status of the child, parental beliefs regarding pain expression and analgesic use in children, cultural values and language barriers can affect management of children\u27s postoperative pain. Targeting the myriad barriers to children\u27s pain management by capitalizing upon the use of tailored interventions may help bridge the gap between the translation of pain management guidelines to the home setting
Bats roosting in public buildings: A preliminary assessment from Moramanga, eastern Madagascar
Madagascar has many synanthropic bat species but relatively little is known about how people interact with them. A preliminary assessment on the presence of bats in buildings and their interactions with people was conducted in the eastern town of Moramanga. Fifty of the 156 buildings were reported to contain active bat colonies and 46 of these were in schools. The bats, two species of Molossidae, roosted principally in the roof spaces of buildings that were more than ten years old. Users of the buildings were relatively tolerant of the bats, although 41 % reported negative attitudes because of the odor of roosting colonies and some concerns over the possibility of contracting respiratory ailments from bat faeces. Guano accumulated in classrooms and was observed on floors and desks. Basic renovations could improve the learning environment for children and could be conducted in a bat friendly way. More research is needed to assess the health risks to people from interacting with bats in Madagascar, and this includes people who study, eat, and handle bats or work and live in buildings or caves where bats roost.
KEY WORDS: Madagascar, Moramanga, building, bats, health
Excited Baryons in the Large Limit
The spectrum of excited -type heavy baryons is considered in the
large limit. The universal form factors for semileptonic
decay to excited charmed baryons are calculated in the large limit. We
find that the Bjorken sum rule (for the slope of the Isgur--Wise function) and
Voloshin sum rule (for the mass of the light degrees of freedom) are saturated
by the first doublet of excited states.Comment: 9 pages, use phyzzx, CALT-68-191
Increases in salience of ethnic identity at work: the roles of ethnic assignation and ethnic identification
To better understand how ethnicity is actually experienced within organisations, we examined reported increases in ethnic identity salience at work and responses to such increases. Thirty British black Caribbean graduate employees were interviewed about how and when they experienced their ethnic identity at work. The findings demonstrated that increased salience in ethnic identity was experienced in two key ways: through âethnic assignationâ (a âpushâ towards ethnic identity) and âethnic identificationâ (a âpullâ towards ethnic identity). We explore how and when ethnic assignation and ethnic identification occur at work, and their relevance to how workplaces are experienced by this group of minority ethnic employees. The findings suggest the need for further research attention to the dynamic and episodic nature of social identity, including ethnic identity, within organisations, and to the impact of such increases in salience of social identities on behaviour at work
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