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E Nordberg

Publications and source records attributed to E Nordberg.

At least 19 recordsLinked to original sources
PubMed2001

Branching fraction and photon energy spectrum for b --> s gamma.

We have measured the branching fraction and photon energy spectrum for the radiative penguin process b-->s gamma. We find Beta(b-->s gamma) = (3.21+/-0.43+/-0.27(+0.18)(-0.10))x10(-4), where the errors are statistical, systematic, and from theory corrections. We obtain first and second moments of the photon energy spectrum above 2.0 GeV, = 2.346+/-0.032+/-0.011 GeV, and - (2) = 0.0226+/-0.0066+/-0.0020 GeV(2), where the errors are statistical and systematic. From the first moment, we obtain (in the modified minimal subtraction renormalization scheme, to order 1/M(3)(B) and beta(0)alpha(2)(s)) the heavy quark effective theory parameter Lambda = 0.35+/-0.08+/-0.10 GeV.

Journal Article↗
PubMed2001

Hadronic mass moments in inclusive semileptonic B meson decays.

We have measured the first and second moments of the hadronic mass-squared distribution in B-->X(c)l nu, for P(lepton)>1.5 GeV/c. We find = 0.251+/-0.066 GeV(2), <(M(2)(X)- )(2)> = 0.576+/-0.170 GeV(4), where M macro(D) is the spin-averaged D meson mass. From that first moment and the first moment of the photon energy spectrum in b-->s gamma, we find the heavy quark effective theory parameter lambda(1) (in the modified minimal subtraction renormalization scheme, to order 1/M(3)(B) and beta(0)alpha(2)(s)) to be -0.24+/-0.11 GeV(2). Using these first moments and the B semileptonic width, and assuming parton-hadron duality, we obtain absolute value of V(cb) = 0.0404+/-0.0013.

Journal Article↗
PubMed2001

Search for the decay upsilon(1S) --> gammaeta(').

We report on a search for the radiative decay Upsilon(1S)-->gammaeta(') in 61.3 pb(-1) of data taken with the CLEO II detector at the Cornell Electron Storage Ring. Three decay chains were investigated, all involving eta(')-->pi(+)pi(-)eta, followed by eta-->gammagamma, eta-->pi(0)pi(0)pi(0), or eta-->pi(+)pi(-)pi(0). We find no candidate events in any of the three cases and set a combined upper limit of 1.6x10(-5) at 90% C.L., significantly smaller than the previous limit. We compare our result to other radiative Upsilon decays, to radiative J/psi decays, and to theoretical predictions.

Journal Article↗
PubMed2001

Bounds on the CP asymmetry in b --> sgamma decays.

We have measured the CP asymmetry A(CP) identical with[gamma(b-->sgamma)-gammab-->sgamma)]/[gamma(b-->sgamma)+gamma(b-->sgamma)] to be A(CP) = (-0.079+/-0.108+/-0.022) (1.0+/-0.030), implying that, at 90% confidence level, A(CP) lies between -0.27 and +0.10. These limits rule out some extreme non-standard-model predictions, but are consistent with most, as well as with the standard model.

Journal Article↗
PubMed2001

Bounds on the CP asymmetry in like-sign dileptons from B(0)B*(0) meson decays.

We have measured the charge asymmetry in like-sign dilepton yields from B(0)B*(0) meson decays using the CLEO detector at the Cornell Electron Storage Ring. We find a(0)(ll) identical with[N(l(+)l(+))-N(l(-)l(-))]/[N(l(+)l(+))+N(l(-)l(-))] = +0.013+/-0.050+/-0.005. We combine this result with a previous, independent measurement and obtain Re(epsilon(B))/(1+ the absolute value of epsilon(B)(2)) = +0.0035+/-0.0103+/-0.0015 (uncertainties are statistical and systematic, respectively) for the CP impurity parameter, epsilon(B).

Journal Article↗
PubMed2001

Observation of new states decaying into Lambda+(c)pi(-)pi(+).

Using 13.7 fb(-1) of data recorded by the CLEO detector at the Cornell Electron Storage Ring, we investigate the spectrum of charmed baryons which decay into Lambda+(c)pi(-)pi(+) and are more massive than the Lambda+(c)(2625) baryon. We find evidence for two new states: one is broad and has an invariant mass roughly 480 MeV above that of the Lambda+(c) baryon; the other is narrow with an invariant mass of 596+/-1+/-2 MeV above the Lambda+(c) mass.

Journal Article↗
PubMed2001

Evidence of New States Decaying into Xi(*)(c)pi.

Using 13.7 fb(-1) of data recorded by the CLEO detector at Cornell Electron Storage Ring, we report evidence of two new charmed baryons: one decaying into Xi(0')(c)pi(+) with the subsequent decay Xi(0')(c)-->Xi(0)(c)gamma, and its isospin partner decaying into Xi(+')(c)pi(-) followed by Xi(+')(c)-->Xi(+)(c)gamma. We measure the following mass differences for the two states: M(Xi(0)(c)gammapi(+))-M(Xi(0)(c)) = 318.2+/-1.3+/-2.9 MeV and M(Xi(+)(c)gammapi(-))-M(Xi(+)(c)) = 324.0+/-1.3+/-3.0 MeV. We interpret these new states as the J(P) = 1 / 2(-) Xi(c1) particles, the charmed-strange analogs of the Lambda(+)(c1)(2593).

Journal Article↗
PubMed2001

Observation of B --> phiK and B --> phiK*.

We have studied two-body charmless hadronic decays of B mesons into the final states straight phiK and phiK(*). Using 9.7 million B&Bmacr; pairs collected with the CLEO II detector, we observe the decays B- --> phiK- and B0--> phiK(*0) with the following branching fractions: B(B--->phiK-) = (5.5(+2.1)(-1.8)+/-0.6)x10(-6) and B(B0--> phiK(*0)) = (11.5(+4.5+1.8)(-3.7-1.7))x10(-6). We also see evidence for the decays B0-->phiK0 and B---> phiK(*-). However, since the statistical significance is not overwhelming for these modes, we determine upper limits of <12.3x10(-6) and <22.5x10(-6) ( 90% confidence level), respectively.

Journal Article↗
PubMed2001

Observation of the Omega(0)(c) Charmed Baryon at CLEO.

The CLEO experiment at the CESR collider has used 13.7 fb(-1) of data to search for the production of the Omega(0)(c) (css ground state) in e(+)e(-) collisions at square root of (s) approximately 10.6 GeV. The modes used to study the Omega(0)(c) are Omega(-)pi(+), Omega(-)pi(+)pi(0), Xi-K-pi(+)pi(+), Xi0K-pi(+), and Omega(-)pi(+)pi(+)pi(-). We observe a signal of 40.4+/-9.0(stat) events at a mass of 2694.6+/-2.6(stat)+/-1.9(syst) MeV/c(2), for all modes combined.

Journal Article↗
PubMed2001

Measurement of the relative branching fraction of upsilon(4S) to charged and neutral B-meson pairs.

We analyze 9.7x10(6) B_B pairs recorded with the CLEO detector to determine the production ratio of charged to neutral B-meson pairs produced at the Upsilon(4S) resonance. We measure the rates for B0-->J/psiK((*)0) and B+-->J/psiK((*)+) decays and use the world-average B-meson lifetime ratio to extract the relative widths f(+-) / f(00) = gamma(Upsilon(4S)-->B+B-) / gamma(Upsilon(4S)-->B0 B-0)) = 1.04+/-0.07(stat)+/-0.04(syst). With the assumption that f(+-)+f(00) = 1, we obtain f(00) = 0.49+/-0.02(stat)+/-0.01(syst) and f(+-) = 0.51+/-0.02(stat)+/-0.01(syst). This production ratio and its uncertainty apply to all exclusive B-meson branching fractions measured at the Upsilon(4S) resonance.

Journal Article↗
PubMed2001

Measurement of the lambda(+)(c) lifetime.

The Lambda+c lifetime is measured using 9.0 fb(-1) of e+e- annihilation data collected on or just below the Upsilon(4S) resonance with the CLEO II.V detector at CESR. Using an unbinned maximum likelihood fit, the Lambda+c lifetime is measured to be 179.6+/-6.9(stat)+/-4.4(syst) fs. The precision of this colliding beam measurement is comparable to other measurements, which are based on fixed-target experiments, with different systematic uncertainties.

Journal Article↗
PubMed2001

Minor surgery at hospitals and clinics in a Kenyan district.

BACKGROUND: Minor surgical operations are performed at almost all hospitals, health centres and dispensaries in Africa. A large proportion of the operations are urgent, prompted by injuries and acute infections. They are rarely recorded and reported systematically, and rates and patterns are poorly known. OBJECTIVE: To describe of all minor surgery performed on a rural African population during one year. DESIGN: Prospective recording and analysis of minor surgical procedures and of the patients undergoing the same procedures. SETTING: Hospitals, health centres, dispensaries and mission clinics in Meru district, Kenya. RESULTS: Out of 26,858 minor operations performed (2,066/100,000 people/year) 22,838 were done at the five hospitals in the district while 2,510 were done at 49 mission clinics (4.3/clinic/month), 764 at ten health centres (6.4/health centre/month) and 620 at 29 dispensaries (1.8/dispensary/month). The most common operations were episiotomy, tooth extraction, wound suture and incision and drainage of abscess. More minor surgery is done on women than on men, and the difference is related to obstetrical procedures. CONCLUSIONS: Relatively few operations were performed at health centres, dispensaries and mission clinics. Possible explanations include perceived quality of care, staff motivation, poor service access outside office hours and service charges.

Adolescent↗
PubMed2000

Study of charmless hadronic B meson decays to pseudoscalar-vector final states.

We report results of searches for charmless hadronic B meson decays to pseudoscalar( pi(+/-), K+/-, pi(0), or K(0)(S))-vector( rho, K(*), or omega) final states. By using 9.7x10(6) BB pairs collected with the CLEO detector, we report the first observation of B(-)--->pi(-)rho(0), B(0)-->pi(+/-)rho(-/+), and B(-)-->pi(-)omega, which are expected to be dominated by hadronic b-->u transitions. The measured branching fractions are (10.4(+3.3)(-3.4)+/-2.1)x10(-6), (27.6(+8.4)(-7.4)+/-4.2)x10(-6), and (11.3(+3.3)(-2.9)+/-1. 4)x10(-6), respectively. Branching fraction upper limits are set for all of the other decay modes investigated.

Journal Article↗
PubMed1998

Airborne surgical outreach services in eastern Africa.

BACKGROUND: African Medical and Research Foundation (AMREF) has for forty years offered airborne specialist surgeons or surgical teams to supplement the major surgery conducted by local hospital staff, particularly in Kenya and Tanzania. OBJECTIVE: To quantify and qualitatively describe the contribution of airborne surgical outreach services in relation to the total surgical output of remote rural hospitals in Kenya and Tanzania. DATA SOURCES: Surgical theatre registration books of one government and two church/mission owned hospitals in Kenya and Tanzania from 1994 to 1995; and service records kept by the surgeons during outreach trips in the same period. RESULTS: AMREF contributed 15.1% of all major operations, and operations performed by AMREF were relatively complex. The average number of AMREF's major operations performed per visit was 17 and per visit day 4.3. Numerous minor operations and examinations, ward rounds and an average of 10 patient consultations per day were done during the visits. CONCLUSIONS: Total population-based operation rates, and rates by sex and age, are useful indicators for monitoring and comparison. Every hospital should report, annually, major operations performed by type and by age and sex of patients, with special mention of operations and consultations performed by visiting teams, if any. Each hospital should also state the estimated population of its current catchment area.

Aviation↗
PubMed1997

[Geriatric psychiatry--a specialty gaining recognition].

Services for elderly, mentally ill people have developed in response to changing needs in society. In 1990 most of the 650 beds allocated to elderly patients in psychiatric hospitals were occupied by long-term care patients. Outpatient programmes hardly existed. In 1995 about 400 beds were allocated to geriatric psychiatry. They were served by 40 physicians and 20 psychologists. Out-patients' clinics were established. Most of the in-patients were short-term admissions. Nowadays, departments of geriatric psychiatry define themselves as diagnostic and short-term units. About a third of the in-patients suffer from dementia, a third from depression, and a third from various other psychiatric disorders. The authors recommend that a special unit for geriatric psychiatry should be established in every county in Norway. Funds should be allocated for professorships at all universities.

Aged↗
PubMed1997

North-South health research collaboration: challenges in institutional interaction.

North-South health development cooperation often includes research financed largely by external donors. The cooperation varies between projects and programmes with regard to subject area, mix of disciplines involved, research methods, training components and project management arrangements. A variety of problems is encountered, but they are rarely described and discussed in published project reports. We authors conducted a study of a small number of European health researchers collaborating with researchers from the Third World. We focused upon projects involving both biomedical and social science researchers, and apart from a literature review three methods were applied: self-administered questionnaires to European researchers, semistructured interviews with five IHCAR researchers, and written summaries by the three authors, each on one recent or ongoing collaborative project of their choice. Most collaborative projects were initiated from the North and are monodisciplinary or partly interdisciplinary in the sense that researchers did independent data collection preceded by joint planning and followed by joint analysis and write-up. There may be disagreements concerning remuneration such as allowances in relation to fieldwork and training. Socio-cultural misunderstanding and conflict was reportedly rare, and no serious problems were reported regarding authorship and publishing. It is concluded that collaborative research is a complex and poorly understood process with considerable potential and worth pursuing despite the problems. Difficulties related to logistics and finance are easily and freely discussed, while there is little evidence that transdisciplinary research is conducted or even discussed. We recommend that published and unpublished reports on collaborative research projects include more detailed accounts of the North-South collaborative arrangements and their management, ethical and financial aspects.

Cooperative Behavior↗
PubMed1997

Health and the elderly in developing countries with special reference to sub-Saharan Africa.

The numbers of elderly people in sub-Saharan Africa are growing rapidly with increasing life expectancy while at the same time the proportions of children in the populations are declining. The number of people 80 years and above increased tenfold in large parts of Africa since the 1950's, and the number of widows is growing fast. All this has several implications, including erosion of the social support by extended families and a dramatic change in the disease pattern. There will be increasing rates of cancer, liver cirrhosis, kidney failure, eye disease, osteoarthrosis, diabetes, mental illness and chronic degenerative illnesses such as cardiovascular disease. Multiple illness and permanent disability will become more common. African health care systems are ill-prepared for this transition, and social security for the elderly need to be improved in the coming years. Local and regional research into morbidity and well-being is important for policy formulation. The situation of different categories of chronically sick needs to be investigated. Improved health in childhood and middle age will probably be followed by improved health in old age, and this may offset the burden on the health care system of the growing number of elderly.

Africa South of the Sahara↗