6,569 research outputs found

    Search for lepton flavor violation via the intense high-energy muon beam

    Full text link
    A deep inerastic scattering process \mutau is discussed to study lepton flavor violation between muons and tau leptons. In supersymmetric models, the Higgs boson mediated diagrams could be important for this reaction. We find that at a muon energy (EμE_{\mu}) higher than 50 GeV, the predicted cross section significantly increases due to the contribution from sea bb-quarks. The number of produced tau leptons can be O(104)\mathcal{O}(10^4) at EμE_{\mu}= 300 GeV from 102010^{20} muons, whereas O(102)\mathcal{O}(10^2) events are given at Eμ=50E_{\mu}= 50 GeV.Comment: Contribution to the 6th International Workshop on Neutrino Factories & Superbeams(NuFact04), Jul. 26-Aug. 1, 2004, Osaka Univerisity, Osaka, Japan, talk given by S.K., to appear in the Proceedings, 3 pages, 4 figure

    Belle II iTOP Optics: Design, Construction and Performance

    Full text link
    The imaging-Time-of-Propogation (iTOP) counter is a new type of ring-imaging Cherenkov counter developed for particle identification at the Belle II experiment. It consists of 16 modules arranged azimuthally around the beam line. Each module consists of one mirror, one prism and two quartz bar radiators. Here we describe the design, acceptance test, alignment, gluing and assembly of the optical components. All iTOP modules have been successfully assembled and installed in the Belle II detector by the middle of 2016. After installation, laser and cosmic ray data have been taken to test the performance of the modules. First results from these tests are presented.Comment: Proceedings of TIPP 2017, May 22 - 26, Beijing, China, 2017; University of Cincinnati preprint UCHEP-17-07. arXiv admin note: text overlap with arXiv:1709.0993

    An imaging time-of-propagation system for charged particle identification at a super B factory

    Full text link
    Super B factories that will further probe the flavor sector of the Standard Model and physics beyond will demand excellent charged particle identification (PID), particularly K/pi separation, for momenta up to 4 GeV/c, as well as the ability to operate under beam backgrounds significantly higher than current B factory experiments. We describe an Imaging Time-of-Propagation (iTOP) detector which shows significant potential to meet these requirements. Photons emitted from charged particle interactions in a Cerenkov radiator bar are internally reflected to the end of the bar, where they are collected on a compact image plane using photodetectors with fine spatial segmentation in two dimensions. Precision measurements of photon arrival time are used to enhance the two dimensional imaging, allowing the system to provide excellent PID capabilities within a reduced detector envelope. Results of the ongoing optimization of the geometric and physical properties of such a detector are presented, as well as simulated PID performance. Validation of simulations is being performed using a prototype in a cosmic ray test stand at the University of Hawaii.Comment: 3 pages, 5 figures, submitted to TIPP09 proceeding

    Meretojan taudista uutta tietoa kansallisen potilasrekisterin avulla

    Get PDF
    Tiedot Meretojan taudin eli suomalaisen perinnöllisen gelsoliiniamyloidoosin taudinkulusta ovat tähän saakka perustuneet suhteellisen pieniin potilassarjoihin. Uuden kansallisen FIN-GAR-potilasrekisterin avulla voidaan paremmin kartoittaa taudin oireita ja niiden yleisyyttä sekä sen luonnollista kulkua. Potilasrekisteriin on tähän mennessä kerätty tiedot 235 potilaasta, ja siihen toivotaan edelleen täydennystä. Rekisterin mukaan ensioireet alkavat yleensä silmistä. Taudin ensisijainen diagnostinen löydös on potilaalle tyypillisesti jo 20–30-vuotiaana kehittyvä sarveiskalvon verkkomainen rappeuma. Muut oireet ja löydökset kehittyvät suurin piirtein samanaikaisesti, mediaanien osuessa 50 ja 60 ikävuoden välille. Naisilla oireet kehittyvät keskimäärin aiemmin ja erityisesti silmäoireet ovat yleisempiä kuin miehillä. Rannekanavaoireyhtymä, sydämentahdistin ja munuaisensiirrot ovat rekisterin potilailla huomattavasti yleisempiä kuin normaaliväestössä. Näiden tarkkaa patologista yhteyttä Meretojan tautiin tutkitaan ­parhaillaan.Peer reviewe

    Flavor and CP Violation Induced by Atmospheric Neutrino Mixing

    Full text link
    Neutrino oscillation experiments suggest existence of new flavor-violating interactions in high energy scale. It may be possible to probe them by the flavor- and CP-violating processes in leptons and hadrons in the supersymmetric (SUSY) models. In this article the third-generation flavor violation is reviewed in the SUSY seesaw model and SUSY SU(5) GUT with the right-handed neutrinos.Comment: 12 pages. Talk at Fujihara Seminar on Neutrino Mass and Seesaw Mechanism (SEESAW 1979-2004), Tsukuba, Ibaraki, Japan, 23-25 Feb 200

    Probing lepton flavor violation signal via e+ e- (gamma gamma) ---> l(i) anti-l(j) in the littlest Higgs model with T-parity at the ILC

    Full text link
    In the littlest Higgs model with T-parity, the new interactions between the mirror leptons and the Standard Model leptons can induce some lepton flavor violation (LFV) processes at loop level. We study the possibility of the ILC to probe the LFV production processes e+e(γγ)lilˉje^+e^-(\gamma\gamma)\rightarrow l_{i}\bar{l}_{j}. Our results show that the rates of γγlilˉj\gamma\gamma\rightarrow l_{i}\bar{l}_{j} can reach 1 fb in optimal cases after reasonable kinematical cuts, which implies that these processes may be observed at the ILC

    Lepton flavour violating Higgs Boson decays, tau --> mu gamma and B(s) --> mu+mu- in the constrained MSSM+NR with large tan beta

    Full text link
    Realistic predictions are made for the rates of lepton flavour violating Higgs boson decays, tau --> mu gamma, mu --> e gamma, Bs --> mu+mu-, Bs --> tau mu and tau --> 3mu, via a top-down analysis of the Minimal Supersymmetric Standard Model(MSSM) constrained by SU(5) unification with right-handed Neutrinos and large tan beta. The third family neutrino Yukawa coupling is chosen to be of order 1, in this way our model bares a significant resemblance to supersymmetric SO(10). In this framework the large PMNS mixings result in potentially large lepton flavour violation. Our analysis predicts tau --> mu gamma and mu --> e gamma rates in the region (10^{-8}-10^{-6}) and (10^{-15}-10^{-14}) respectively. We also show that the rates for lepton flavour violating Higgs decays can be as large as 10^{-7}. The non-decoupling nature of H --> tau mu is observed which leads to its decay rate becoming comparable to that for tau --> mu gamma for large values of m_0 and M_1/2. We also find that the present bound on Bs --> mu+mu- is an important constraint on the rate of lepton flavour violating Higgs decays. The recently measured Bs-Bsbar mixing parameter Delta Ms is also investigated.Comment: 27 pages, 15 postscript figures, 1 table. Small changes made to the text and title. Updated references. Bs-Bsbar analysis also include

    Lepton Flavour Violating Leptonic/Semileptonic Decays of Charged Leptons in the Minimal Supersymmetric Standard Model

    Full text link
    We consider the leptonic and semileptonic (SL) lepton flavour violating (LFV) decays of the charged leptons in the minimal supersymmetric standard model (MSSM). The formalism for evaluation of branching fractions for the SL LFV charged-lepton decays with one or two pseudoscalar mesons, or one vector meson in the final state, is given. Previous amplitudes for the SL LFV charged-lepton decays in MSSM are improved, for instance the γ\gamma-penguin amplitude is corrected to assure the gauge invariance. The decays are studied not only in the model-independent formulation of the theory in the frame of MSSM, but also within the frame of the minimal supersymmetric SO(10) model within which the parameters of the MSSM are determined. The latter model gives predictions for the neutrino-Dirac Yukawa coupling matrix, once free parameters in the model are appropriately fixed to accommodate the recent neutrino oscillation data. Using this unambiguous neutrino-Dirac Yukawa couplings, we calculate the LFV leptonic and SL decay processes assuming the minimal supergravity scenario. A very detailed numerical analysis is done to constrain the MSSM parameters. Numerical results for SL LFV processes are given, for instance for tau -> e (mu) pi0, tau -> e (mu) eta, tau -> e (mu) eta', tau -> e (mu) rho0, tau -> e (mu) phi, tau -> e (mu) omega, etc.Comment: 36 pages, 3 tables, 5 .eps figure

    Search for the Lepton-Flavor-Violating Decay τμη\tau^- \to \mu^- \eta at Belle

    Full text link
    We have searched for the Lepton Flavor Violating decay τμη\tau^- \to \mu^- \eta using a data sample of 84.3 fb1^{-1} accumulated with the Belle detector at KEK. The η\eta-meson was detected through the decay modes: ηγγ\eta \to \gamma\gamma and π+ππ0\pi^+\pi^-\pi^0. No signal candidates are found, and we obtain an upper limit for the branching fraction B(τμη)<3.4×107{\cal B}(\tau^- \to \mu^- \eta)<3.4\times 10^{-7} at the 90% confidence level.Comment: Submitted to Phys.Rev.Let
    corecore