813 research outputs found
Spin-Orbit and Tensor Forces in Heavy-quark Light-quark Mesons: Implications of the New Ds state at 2.32 GeV
We consider the spectroscopy of heavy-quark light-quark mesons with a simple
model based on the non-relativistic reduction of vector and scalar exchange
between fermions. Four forces are induced: the spin-orbit forces on the light
and heavy quark spins, the tensor force, and a spin-spin force. If the vector
force is Coulombic, the spin-spin force is a contact interaction, and the
tensor force and spin-orbit force on the heavy quark to order are
directly proportional. As a result, just two independent parameters
characterize these perturbations. The measurement of the masses of three p-wave
states suffices to predict the mass of the fourth. This technique is applied to
the system, where the newly discovered state at 2.32 GeV provides the
third measured level, and to the system. The mixing of the two
p-wave states is reflected in their widths and provides additional constraints.
The resulting picture is at odds with previous expectations and raises new
puzzles.Comment: 6 pages, 1 figur
Measurement of Orbitally Excited D-Mesons at CDF II
Measurement of Orbitally Excited D-Mesons at CDF II Igor V. Gorelov (For the
CDF Collaboration)
Talk given on behalf of the CDF Collaboration at the First Meeting of the APS
Topical Group on Hadronic Physics, GHP 2004, 24-26 October 2004, FERMILAB.
Results on the first measurement of orbitally excited neutral D-meson states,
D*_2 and D_1, produced in hadron collisions at Tevatron are presented. Using
data from the displaced track trigger, CDF II collects the largest world sample
of these states in decay modes D*+ pi-, D+ pi-. Masses and widths of both
states have been measured with precision better than or comparable to the world
average.Comment: 6 pages, 5 figures, talk given on behalf of the CDF Collaboration at
the First Meeting of the APS Topical Group on Hadronic Physics, GHP 2004, Oct
24-26,2004, Fermilab, Batavia, Illinoi
Keratoderma Hereditaria Mutilans (Vohwinkel's Syndrome): A Trial of Isotretinoin
An 8-year-old girl with the classic findings of keraloderma heredilaria mutilans (Vohwinkel's syndrome) was seen. Treatment with isotretinoin was instituted to decrease the hyperkeratosis and to prevent further autoamputation. After a 12-week course at 2 mg per kg per day, the patient had only minimal decrease in the amount of hyperkeratosis. Because of Ihe well-known long-term risks of systematic retinoids and her suboptimal improvement, therapy was discontinued.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74902/1/j.1525-1470.1985.tb01056.x.pd
CLEO Contributions to Tau Physics
We review many of the contributions of the CLEO experiment to tau physics.
Topics discussed are: branching fractions for major decay modes and tests of
lepton universality; rare decays; forbidden decays; Michel parameters and spin
physics; hadronic sub-structure and resonance parameters; the tau mass, tau
lifetime, and tau neutrino mass; searches for CP violation in tau decay; tau
pair production, dipole moments, and CP violating EDM; and tau physics at
CLEO-III and at CLEO-c.Comment: Invited talk at the Seventh International Workshop on Tau Lepton
Physics (TAU02), Santa Cruz, Ca, USA, Sept 2002, 14 pages, LaTeX, 21 eps
figure
Indications for Factorization and from Rare B Decay Data
Surveying known hadronic rare B decays, we find that the factorization
approximation can give a coherent account of , and
data and give predictions for , and modes,
{\it if is taken as negative} (in standard phase convention)
rather than positive. As further confirmation, we expect a lower
value at B Factories as compared to current fits, and mixing close to LEP
bounds at SLD and CDF.Comment: 11 pages, revtex, 4 figures (unchanged and eps files included);
version (including title and abstract change) to appear in Phys. Rev. Let
Efficacy and Safety of a Low-level Laser Device in the Treatment of Male and Female Pattern Hair Loss: A Multicenter, Randomized, Sham Device-controlled, Double-blind Study
Significance Male and female pattern hair loss are common, chronic dermatologic disorders with limited therapeutic options. In recent years, a number of commercial devices using low-level laser therapy have been promoted, but there have been little peer-reviewed data on their efficacy. Objective: To determine whether treatment with a low-level laser device, the US FDA-cleared HairMax Lasercomb®, increases terminal hair density in both men and women with pattern hair loss. Methods: Randomized, sham device-controlled, double-blind clinical trials were conducted at multiple institutional and private practices. A total of 146 male and 188 female subjects with pattern hair loss were screened. A total of 128 male and 141 female subjects were randomized to receive either a lasercomb (one of three models) or a sham device in concealed sealed packets, and were treated on the whole scalp three times a week for 26 weeks. Terminal hair density of the target area was evaluated at baseline and at 16- and 26-week follow-ups, and analyzed to determine whether the hypothesis formulated prior to data collection, that lasercomb treatment would increase terminal hair density, was correct. The site investigators and the subjects remained blinded to the type of device they dispensed/received throughout the study. The evaluator of masked digital photographs was blinded to which trial arm the subject belonged. Results: Seventy-eight, 63, 49, and 79 subjects were randomized in four trials of 9-beam lasercomb treatment in female subjects, 12-beam lasercomb treatment in female subjects, 7-beam lasercomb treatment in male subjects, and 9- and 12-beam lasercomb treatment in male subjects, compared with the sham device, respectively. Nineteen female and 25 male subjects were lost to follow-up. Among the remaining 122 female and 103 male subjects in the efficacy analysis, the mean terminal hair count at 26 weeks increased from baseline by 20.2, 20.6, 18.4, 20.9, and 25.7 per cm2 in 9-beam lasercomb-treated female subjects, 12-beam lasercomb-treated female subjects, 7-beam lasercomb-treated male subjects, and 9- and 12-beam lasercomb-treated male subjects, respectively, compared with 2.8 (p < 0.0001), 3.0 (p < 0.0001), 1.6 (p = 0.0017), 9.4 (p = 0.0249), and 9.4 (p = 0.0028) in sham-treated subjects (95 % confidence interval). The increase in terminal hair density was independent of the age and sex of the subject and the lasercomb model. Additionally, a higher percentage of lasercomb-treated subjects reported overall improvement of hair loss condition and thickness and fullness of hair in self-assessment, compared with sham-treated subjects. No serious adverse events were reported in any subject receiving the lasercomb in any of the four trials. Conclusions and relevance We observed a statistically significant difference in the increase in terminal hair density between lasercomb- and sham-treated subjects. No serious adverse events were reported. Our results suggest that low-level laser treatment may be an effective option to treat pattern hair loss in both men and women. Additional studies should be considered to determine the long-term effects of low-level laser treatment on hair growth and maintenance, and to optimize laser modality
Extracting information on CKM phases, electro-weak penguins and new physics from B --> VV decays
We derive constraints for modes ($V= vector meson) that allow
aquantitative assessment of the contributions from electroweak penguins (EWP)
and/or new physics. Interplay of direct CP with oscillation studies then leads
to the extraction of the angles alpha and gamma, using B--> K* omega rho and
B--> rho omega (phi) respectively, if by using our constraint equations it can
be experimentally demonstrated that color-suppressed EWP are small.Comment: 12 pages, 0 figures; revised and expande
Phenomenological Study of Strong Decays of Heavy Hadrons in Heavy Quark Effective Theory
The application of the tensor formalism of the heavy quark effective theory
(HQET) at leading order to strong decays of heavy hadrons is presented.
Comparisons between experimental and theoretical predictions of ratios of decay
rates for B mesons, D mesons and kaons are given. The application of HQET to
strange mesons presents some encouraging results. The spin-flavor symmetry is
used to predict some decay rates that have not yet been measured.Comment: 10 page
Changing Dose of Progesterone Results in Sudden Changes in Frequency of Luteinizing Hormone Pulses and Secretion of 17β-Estradiol in Bovine Females
The aim of the present study was to elucidate the time course according to which changes in circulating concentrations of progesterone influence pulsatile secretion of LH and secretion of 17β-estradiol. Our working hypothesis was that changing the dose of progesterone would result in changes in frequency of LH pulses and secretion of 17β-estradiol within 72 h. Five days after behavioral estrus, thirty-three cows were randomly assigned to one of five groups: 1) control, no treatment (CONT, n = 5); 2) treatment with two progesterone-releasing intravaginal devices (PRIDs) for 11 days (2PRID, 5-6 ng/ml plasma progesterone, n = 7); 3) treatment with a 0.5 PRID for 11 days (0.5PRID, 1-2 ng/ml plasma progesterone, n = 7); 4) treatment with 2 PRIDs for 8 days followed by treatment with a 0.5 PRID for 3 days (2-0.5PRID, n = 7); and 5) treatment with a 0.5 PRID for 8 days followed by treatment with 2 PRIDs for 3 days (0.5-2PRID, n = 7). Cows subject to PRID treatments received injections of prostaglandin F2 on Days 1 and 2 (Day 0 = day of initiation of PRID treatments, fifth day of the estrous cycle in CONT cows) to lyse the existing corpus luteum. Cows were bled for 12 h at 15-min intervals on Day 7.5 of the treatment period (twelfth day of the estrous cycle in CONT cows). The dose of progesterone was changed on Day 8 in cows that were assigned to the 2-0.5PRID and 0.5-2PRID groups, and blood collections continued an additional 72 h to characterize profiles of circulating concentrations of LH and 17β-estradiol. Cows treated with a 0.5 PRID had a greater (p \u3c 0.05) number of LH pulses and higher (p \u3c 0.05) concentrations of 17β-estradiol throughout the entire blood collection period than cows in the 2PRID and CONT groups. An increase in the number of LH pulses was detected within 6 h after the change from the high to the low dose of progesterone (2-0.5PRID), and frequency of LH pulses was similar to that of cows in the 0.5PRID group for the remainder of the period of blood collection. LH pulse frequency declined within 6 h after the shift from the low to the high dose of progesterone (0.5-2PRID) and was similar to that of cows in the 2PRID group by 12 h after the dose was changed. Within 6 h after the dose of progesterone was changed, circulating concentrations of 17p-estradiol increased (p \u3c 0.05) in cows shifted from the high to low dose (2-0.5PRID) and declined (p \u3c 0.05) after the dose of progesterone was changed from low to high (0.5-2PRID). We conclude that changing the circulating concentrations of progesterone concurrently affects frequency of pulsatile LH release and secretion of 17β-estradiol within 6-24 h
Constraints on R-parity violating supersymmetry from leptonic and semileptonic tau, B_d and B_s decays
We put constraints on several products of R-parity violating lambda lambda'
and lambda' lambda' type couplings from leptonic and semileptonic tau, B_d and
B_s decays. Most of them are one to two orders of magnitude better than the
existing bounds, and almost free from theoretical uncertainties. A significant
improvement of these bounds can be made in high luminosity tau-charm or B
factories.Comment: 14 pages, latex. A few references added, two typos corrected. Version
to be published in Physical Review
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