2,443 research outputs found

    Prospects for detection of Υ(1D)Υ(1S)ππ\Upsilon(1D) \to \Upsilon(1S) \pi \pi via Υ(3S)Υ(1D)+X\Upsilon(3S) \to \Upsilon(1D) + X

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    At least one state in the first family of D-wave bbˉb \bar b quarkonium levels has been discovered near the predicted mass of 10.16 GeV/c2c^2. This state is probably the one with J=2. This state and the ones with J=1 and J=3 may contribute a detectable amount to the decay Υ(1D)Υ(1S)ππ\Upsilon(1D) \to \Upsilon(1S) \pi \pi, depending on the partial widths for these decays for which predictions vary considerably. The prospects for detection of the chain Υ(3S)Υ(1D)+XΥππ+X\Upsilon(3S) \to \Upsilon(1D) + X \to \Upsilon \pi \pi + X are discussed.Comment: 4 pages, LaTeX, 1 figure, to be published in Phys. Rev. D, comment added after Eq. (2

    Searching for the MSW Enhancement

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    We point out that the length scale associated with the MSW effect is the radius of the Earth. Therefore to verify matter enhancement of neutrino oscillations, it will be necessary to study neutrinos passing through the Earth. For the parameters of MSW solutions to the solar neutrino problem, the only detectable effects occur in a narrow band of energies from 5 to 10 MeV. We propose that serious consideration be given to mounting an experiment at a location within 9.5 degrees of the equator.Comment: 10 pages, RevTe

    Nonet Symmetry and Two-Body Decays of Charmed Mesons

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    The decay of charmed mesons into pseudoscalar (P) and vector (V) mesons is studied in the context of nonet symmetry. We have found that it is badly broken in the PP channels and in the P sector of the PV channels as expected from the non-ideal mixing of the \eta and the \eta'. In the VV channels, it is also found that nonet symmetry does not describe the data well. We have found that this discrepancy cannot be attributed entirely to SU(3) breaking at the usual level of 20--30%. At least one, or both, of nonet and SU(3) symmetry must be very badly broken. The possibility of resolving the problem in the future is also discussed.Comment: 9 pages, UTAPHY-HEP-

    Relativistic Effects in S-Wave Quarkonium Decay

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    The decay widths of S-wave quarkonia (\etc,\etb\to \gg{~~and~~} \J,\U\to\ee) are calculated on the basis of a quasipotential approach. The nontrivial dependence on relative quark motion of decay amplitude is taken into consideration via quarkonium wave function. It is shown that relativistic corrections may be large (10-50 %) and comparable with QCD corrections.Comment: 10 pages, no figure

    Heterozygosity at Gm Loci Associated with Humoral Immunity to Osteosarcoma

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    Familial clustering of osteosarcoma suggests the involvement of genetic factors (1, 2), and the demonstration of a high incidence of osteosarcoma-specific antibodies (3, 4), as well as tumor-specific cell-mediated immunity (5) in patients and their relatives, indicates the involvement of immunological factors in the pathogenesis of this disease. Certain Gm allotypes (genetic markers of IgG) have been shown to be associated with a high relative risk of some forms of cancer. For instance, in Caucasians an unusual Gm haplotype--Gm 1,3;5,13,14--has been found to be associated with neuroblastoma (6), and an increased frequency of Gm (2) has been reported in patients with malignant melanoma (7, 8). A recent report has shown an association of the Gm 1,2; 13,15,16,21 phenotype with lung cancer and primary hepatoma in the Japanese (9). To our knowledge, however, the possible role of Gm allotypes in predisposition to osteosarcoma has not been examined. Immune responsiveness to a variety of antigens in both experimental animals and humans has been shown to be controlled either by major histocompatibility complex (MHC)-linked immune response (Ir) genes or by allotype-linked Ir genes (10-13). In some instances an interactive effect of these two unlinked genetic systems has been observed (12). It is possible that MHC-linked or allotype-linked Ir genes may also influence humoral immunity to tumor antigens. In this report we present evidence for complementary Ir genes controlling immune responses to osteosarcoma-associated antigens (OSAA)

    Higgs particle detection using jets

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    We study the possibility of detecting the Higgs boson in the intermediate mass range via its two jet channel. We consider only Higgs bosons produced in association with a ttˉt \bar{t} pair. Both tt and tˉ\bar{t} are required to decay semileptonically to reduce the QCD background. The signal is compared with the main background, ttˉ+2t \bar{t} + 2 jets, after appropriate cuts. A sizable signal above background is seen in our simulation at the parton level. Use of the ttˉZt\bar{t}Z channel with Z Z decaying to l+ll^+ l^- is suggested for eliminating theoretical uncertainties in determining the ttˉHt \bar{t}H signal.Comment: 10 pages, Fig.1 a,b,c,d(surve on request), plain tex, PVAM-HEP-93-

    A Chinese Chan-Based Mind-Body Intervention Improves Sleep on Patients with Depression: A Randomized Controlled Trial

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    Sleep disturbance is a common problem associated with depression, and cognitive-behavioral therapy (CBT) is a more common behavioral intervention for sleep problems. The present study compares the effect of a newly developed Chinese Chan-based intervention, namely Dejian mind-body intervention (DMBI), with the CBT on improving sleep problems of patients with depression. Seventy-five participants diagnosed with major depressive disorder were randomly assigned to receive 10 weekly sessions of CBT or DMBI, or placed on a waitlist. Measurements included ratings by psychiatrists who were blinded to the experimental design, and a standardized questionnaire on sleep quantity and quality was obtained before and after the 10-week intervention. Results indicated that both the CBT and DMBI groups demonstrated significantly reduced sleep onset latency and wake time after sleep onset (effect size range = 0.46–1.0, P ≤ 0.05) as compared to nonsignificant changes in the waitlist group (P > 0.1). Furthermore, the DMBI group, but not the CBT or waitlist groups, demonstrated significantly reduced psychiatrist ratings on overall sleep problems (effect size = 1.0, P = 0.00) and improved total sleep time (effect size = 0.8, P = 0.05) after treatment. The present findings suggest that a Chinese Chan-based mind-body intervention has positive effects on improving sleep in individuals with depression

    Gluon fragmentation to 1D2^1D_2 quarkonia

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    Gluon fragmentation to heavy JPC=2+J^{PC}=2^{-+} quarkonia is studied herein. We compute these D-wave states' polarized fragmentation functions and find that they are enhanced by large numerical prefactors. The prospects for detecting the lowest lying 1D2^1D_2 charmonium state at the Tevatron are discussed.Comment: 10 pages with 4 uuencoded figures, CALT-68-195

    Relativistic and Binding Energy Corrections to Direct Photon Production In Upsilon Decay

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    A systematic gauge-invariant method is used to calculate the rate for an upsilon meson to decay inclusively into a prompt photon. An expansion is made in the quark relative velocity v, which is a small natural parameter for heavy quark systems. Inclusion of these O(v^2) corrections tends to increase the photon rate in the middle z range and to lower it for larger z, a feature supported by the data.Comment: 13 pages, LateX, One figure (to be published in Phys. Rev. D, Sept. 1, 1996
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