324 research outputs found

    Lepton flavor violation decays τμP1P2\tau^-\to \mu^- P_1 P_2 in the topcolor-assisted technicolor model and the littlest Higgs model with TT parity

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    The new particles predicted by the topcolor-assisted technicolor (TC2TC2) model and the littlest Higgs model with T-parity (called LHTLHT model) can induce the lepton flavor violation (LFVLFV) couplings at tree level or one loop level, which might generate large contributions to some LFVLFV processes. Taking into account the constraints of the experimental data on the relevant free parameters, we calculate the branching ratios of the LFVLFV decay processes τμP1P2\tau^-\to\mu^- P_1 P_2 with P1P2P_1 P_2 = π+π\pi^+\pi^-, K+KK^+K^- and K0K0ˉK^0\bar{K^0} in the context of these two kinds of new physics models. We find that the TC2TC2 model and the LHTLHT model can indeed produce significant contributions to some of these LFVLFV decay processes.Comment: 24 pages, 7 figure

    Dynamical chiral symmetry breaking in gauge theories with extra dimensions

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    We investigate dynamical chiral symmetry breaking in vector-like gauge theories in DD dimensions with (D4D-4) compactified extra dimensions, based on the gap equation (Schwinger-Dyson equation) and the effective potential for the bulk gauge theories within the improved ladder approximation. The non-local gauge fixing method is adopted so as to keep the ladder approximation consistent with the Ward-Takahashi identities. Using the one-loop MSˉ\bar{\rm MS} gauge coupling of the truncated KK effective theory which has a nontrivial ultraviolet fixed point (UV-FP) gg_* for the (dimensionless) bulk gauge coupling g^{\hat g}, we find that there exists a critical number of flavors, NfcritN_f^{\rm crit} (4.2,1.8\simeq 4.2, 1.8 for D=6,8D=6, 8 for SU(3) gauge theory): For Nf>NfcritN_f > N_f^{\rm crit}, the dynamical chiral symmetry breaking takes place not only in the ``strong-coupling phase'' (g^>g{\hat g} >g_*) but also in the ``weak-coupling phase'' (g^<g{\hat g} <g_*) when the cutoff is large enough. For Nf<NfcritN_f < N_f^{\rm crit}, on the other hand, only the strong-coupling phase is a broken phase and we can formally define a continuum (infinite cutoff) limit, so that the physics is insensitive to the cutoff in this case. We also perform a similar analysis using the one-loop ``effective gauge coupling''. We find the NfcritN_f^{\rm crit} turns out to be a value similar to that of the MSˉ\bar{\rm MS} case, notwithstanding the enhancement of the coupling compared with that of the MSˉ\bar{\rm MS}.Comment: REVTEX4, 38 pages, 18 figures. The abstract is shortened; version to be published in Phys. Rev.

    Observation of Scaling Violations in Scaled Momentum Distributions at HERA

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    Charged particle production has been measured in deep inelastic scattering (DIS) events over a large range of xx and Q2Q^2 using the ZEUS detector. The evolution of the scaled momentum, xpx_p, with Q2,Q^2, in the range 10 to 1280 GeV2GeV^2, has been investigated in the current fragmentation region of the Breit frame. The results show clear evidence, in a single experiment, for scaling violations in scaled momenta as a function of Q2Q^2.Comment: 21 pages including 4 figures, to be published in Physics Letters B. Two references adde

    D* Production in Deep Inelastic Scattering at HERA

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    This paper presents measurements of D^{*\pm} production in deep inelastic scattering from collisions between 27.5 GeV positrons and 820 GeV protons. The data have been taken with the ZEUS detector at HERA. The decay channel D+(D0Kπ+)π+D^{*+}\to (D^0 \to K^- \pi^+) \pi^+ (+ c.c.) has been used in the study. The e+pe^+p cross section for inclusive D^{*\pm} production with 5<Q2<100GeV25<Q^2<100 GeV^2 and y<0.7y<0.7 is 5.3 \pms 1.0 \pms 0.8 nb in the kinematic region {1.3<pT(D±)<9.01.3<p_T(D^{*\pm})<9.0 GeV and η(D±)<1.5| \eta(D^{*\pm}) |<1.5}. Differential cross sections as functions of p_T(D^{*\pm}), η(D±),W\eta(D^{*\pm}), W and Q2Q^2 are compared with next-to-leading order QCD calculations based on the photon-gluon fusion production mechanism. After an extrapolation of the cross section to the full kinematic region in p_T(D^{*\pm}) and η\eta(D^{*\pm}), the charm contribution F2ccˉ(x,Q2)F_2^{c\bar{c}}(x,Q^2) to the proton structure function is determined for Bjorken xx between 2 \cdot 104^{-4} and 5 \cdot 103^{-3}.Comment: 17 pages including 4 figure

    The role of emotions on consumers’ satisfaction within the fitness context

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    Previous studies have suggested that consumption-related emotions are important to understand post-purchase reactions. This study examines the relationship between fitness consumers’ emotions and overall satisfaction. After an initial step of free-thought listing and content validity, followed by a pre-test, a survey was conducted among consumers of five different fitness centers (n=786). The questionnaire included measures to assess positive and negative emotions, as well as overall satisfaction with the fitness center. The results gathered through a structural equation model provide evidence that negative emotion experienced by consumers impacts negatively overall satisfaction, while positive emotion have a positive effect on overall satisfaction. These findings suggest managerial implications, such as the need to collect consumers’ perceptions of both tangible and intangible aspects of the services, listen costumers’ opinions in a regular basis, and provide regular training to staff members, in order to identify the triggers of positive emotions and contribute to increased levels of overall satisfaction. Guidelines for future research within the fitness context are also suggested.Estudos precedentes sugerem que as emoções relacionadas com o consumo são importantes para compreender as reações dos consumidores após a compra. Este estudo analisa a relação entre as emoções dos consumidores de fitness e satisfação global. Depois de uma etapa inicial de listagem de pensamento-livre e validade de conteúdo, seguido de um pré-teste, foi realizada uma pesquisa entre os consumidores de cinco centros de fitness diferentes (n = 786). O questionário incluiu medidas para avaliar as emoções positivas e negativas, bem como a satisfação global com o centro de fitness. Os resultados obtidos através de um modelo de equações estruturais forneceram evidências de que as emoções negativas vivenciadas pelos consumidores impactam negativamente a satisfação global, enquanto as emoções positivas têm um efeito positivo sobre a satisfação global. Estes resultados sugerem implicações para os gestores, tais como a necessidade de recolher informação sobre a perceção dos consumidores dos aspetos tangíveis e intangíveis dos serviços, ouvir regularmente as opiniões dos consumidores e facultar formação regular aos colaboradores. Isto permitirá identificar os aspetos que desencadeiam emoções positivas e contribuir para o aumento dos níveis de satisfação global. Orientações para futuras pesquisas no contexto de fitness também são sugeridas.Sin financiación0.185 SJR (2015) Q3, 1090/1779 Medicine (miscellaneous); Q4, 177/229 Health (social science), 112/128 Sports scienceUE

    Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set

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    We report a measurement of the bottom-strange meson mixing phase \beta_s using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays in which the quark-flavor content of the bottom-strange meson is identified at production. This measurement uses the full data set of proton-antiproton collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity. We report confidence regions in the two-dimensional space of \beta_s and the B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2, -1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in agreement with the standard model expectation. Assuming the standard model value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +- 0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +- 0.009 (syst) ps, which are consistent and competitive with determinations by other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012

    Termination of STING responses is mediated via ESCRT-dependent degradation

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    Published online 4 May 2023cGAS-STING signalling is induced by detection of foreign or mislocalised host double-stranded (ds)DNA within the cytosol. STING acts as the major signalling hub, where it controls production of type I interferons and inflammatory cytokines. Basally, STING resides on the ER membrane. Following activation STING traffics to the Golgi to initiate downstream signalling and subsequently to endolysosomal compartments for degradation and termination of signalling. While STING is known to be degraded within lysosomes, the mechanisms controlling its delivery remain poorly defined. Here we utilised a proteomics-based approach to assess phosphorylation changes in primary murine macrophages following STING activation. This identified numerous phosphorylation events in proteins involved in intracellular and vesicular transport. We utilised high-temporal microscopy to track STING vesicular transport in live macrophages. We subsequently identified that the endosomal complexes required for transport (ESCRT) pathway detects ubiquitinated STING on vesicles, which facilitates the degradation of STING in murine macrophages. Disruption of ESCRT functionality greatly enhanced STING signalling and cytokine production, thus characterising a mechanism controlling effective termination of STING signalling.Katherine R Balka, Rajan Venkatraman, Tahnee L Saunders, Angus Shoppee, Ee Shan Pang, Zoe Magill, Jihane Homman-Ludiye, Cheng Huang, Rachael M Lane, Harrison M York, Peck Tan, Ralf B Schittenhelm, Senthil Arumugam, Benjamin T Kile, Meredith O, Keeffe, Dominic De Nard

    Measurement of the reaction γpϕp\gamma^*p \rightarrow \phi p in deep inelastic e+pe^+p scattering at HERA

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    The production of phi mesons in the reaction e(+)p --> e(+)phi p (phi --> K+K-), for 7 phi p cross section rises strongly with W. This behaviour is similar to that previously found for the gamma*p --> rho(0)p cross section. This strong dependence cannot be explained by production through soft pomeron exchange, It is, however, consistent with perturbative QCD expectations, where it reflects the rise of the gluon momentum density in the proton at small x. The ratio of sigma(phi)/sigma(rho(0)), which has previously been determined by ZEUS to be 0.065 +/- 0.013 (stat.) in photoproduction at a mean W of 70 GeV, is measured to be 0.18 +/- 0.05 (stat.) +/- 0.03 (syst.) at a mean Q(2) of 12.3 GeV2 and mean W of approximate to 100 GeV and is thus approaching at large Q(2) the value of 2/9 predicted from the quark charges of the vector mesons and a flavour independent production mechanism

    Curvature-bias corrections using a pseudomass method

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    Momentum measurements for very high momentum charged particles, such as muons from electroweak vector boson decays, are particularly susceptible to charge-dependent curvature biases that arise from misalignments of tracking detectors. Low momentum charged particles used in alignment procedures have limited sensitivity to coherent displacements of such detectors, and therefore are unable to fully constrain these misalignments to the precision necessary for studies of electroweak physics. Additional approaches are therefore required to understand and correct for these effects. In this paper the curvature biases present at the LHCb detector are studied using the pseudomass method in proton-proton collision data recorded at centre of mass energy √s = 13 TeV during 2016, 2017 and 2018. The biases are determined using Z → μ+μ- decays in intervals defined by the data-taking period, magnet polarity and muon direction. Correcting for these biases, which are typically at the 10-4 GeV-1 level, improves the Z → μ+μ- mass resolution by roughly 18% and eliminates several pathological trends in the kinematic-dependence of the mean dimuon invariant mass
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