466 research outputs found

    Bosonic Seesaw in the Unparticle Physics

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    Recently, conceptually new physics beyond the Standard Model has been proposed by Georgi, where a new physics sector becomes conformal and provides "unparticle" which couples to the Standard Model sector through higher dimensional operators in low energy effective theory. Among several possibilities, we focus on operators involving the (scalar) unparticle, Higgs and the gauge bosons. Once the Higgs develops the vacuum expectation value (VEV), the conformal symmetry is broken and as a result, the mixing between the unparticle and the Higgs boson emerges. In this paper, we consider a natural realization of bosonic seesaw in the context of unparticle physics. In this framework, the negative mass squared or the electroweak symmetry breaking vacuum is achieved as a result of mass matrix diagonalization. In the diagonalization process, it is important to have zero value in the (1,1)-element of the mass matrix. In fact, the conformal invariance in the hidden sector can actually assure the zero of that element. So, the bosonic seesaw mechanism for the electroweak symmetry breaking can naturally be understood in the framework of unparticle physics.Comment: 5 pages, no figure; added one more referenc

    The Gaugephobic Higgs

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    We present a class of models that contains Randall-Sundrum and Higgsless models as limiting cases. Over a wide range of the parameter space WW scattering is mainly unitarized by Kaluza-Klein partners of the W and Z, and the Higgs particle has suppressed couplings to the gauge bosons. Such a gaugephobic Higgs can be significantly lighter than the 114 GeV LEP bound for a standard Higgs, or heavier than the theoretical upper bound. These models predict a suppressed single top production rate and unconventional Higgs phenomenology at the LHC: the Higgs production rates will be suppressed and the Higgs branching fractions modified. However, the more difficult the Higgs search at the LHC is, the easier the search for other light resonances (like Z', W', t', exotic fermions) will be.Comment: 20 pages, 3 figure

    On the presentation of the LHC Higgs Results

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    We put forth conclusions and suggestions regarding the presentation of the LHC Higgs results that may help to maximize their impact and their utility to the whole High Energy Physics community.Comment: Conclusions from the workshops "Likelihoods for the LHC Searches", 21-23 January 2013 at CERN, "Implications of the 125 GeV Higgs Boson", 18-22 March 2013 at LPSC Grenoble, and from the 2013 Les Houches "Physics at TeV Colliders" workshop. 16 pages, 3 figures. Version 2: Comment added on the first publication of signal strength likelihoods in digital form by ATLA

    Finite Gluon Fusion Amplitude in the Gauge-Higgs Unification

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    We show that the gluon fusion amplitude in the gauge-Higgs unification scenario is finite in any dimension regardless of its nonrenormalizability. This result is supported by the fact that the local operator describing the gluon fusion process is forbidden by the higher dimensional gauge invariance. We explicitly calculate the gluon fusion amplitude in an arbitrary dimensional gauge-Higgs unification model and indeed obtain the finite result.Comment: 15 pages, final version to appear in MPL

    Temporal Control of the Host-Guest Properties of a Calix[6]arene Receptor by the Use of a Chemical Fuel

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    The host-guest interaction of a 1,3,5-trisaminocalix[6]arene receptor with N-methylisoquinolinium trifluoromethanesulfonate (Kassof 500 ± 30 M-1in CD2Cl2) can be dissipatively driven by means of 2-cyano-2-(4′-chloro)phenylpropanoic acid used as a convenient chemical fuel. When the fuel is added to a dichloromethane solution containing the above complex, the host is induced to immediately release the guest in the bulk solution. Consumption of the fuel allows the guest to be re-uptaken by the host. The operation can be satisfactorily reiterated with four subsequent additions of fuel, producing four successive release-reuptake cycles. The percentage of the guest temporarily released in the bulk solution by the host and the time required for the reuptake process can be finely regulated by varying the quantities of added fuel

    A clean signal for a top-like isosinglet fermion at the Large Hadron Collider

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    We predict a clean signal at the Large Hadron Collider (s)\sqrt s)=14 TeV for a scenario where there is a top-like, charge +2/3 vectorlike isosinglet fermion. Such a quark, via mixing with the standard model top, can undergo decays via both flavour-changing Z-boson coupling and flavour-changing Yukawa interactions. We concentrate on the latter channel, and study the situation where, following its pair-production, the heavy quark pair gives rise to two tops and two Higgs boson. We show that the case where each Higgs decays in the bbˉb\bar{b} channel, there can be a rather distinct and background-free signal that can unveil the existence of the vectorlike isosinglet quark of this kind.Comment: 14 pages, 5 figures, 4 table

    Alexithymia and immunoendocrine parameters in patients affected by systemic lupus erythematosus and rheumatoid arthritis

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    Objective: Aim of this study was to evaluate the prevalence of alexithymia in patients affected by SLE or RA and to investigate the correlation between alexithymia and immunoendocrine parameters (PRL, hGH, IL-6 and TNF-alfa). Methods: Twenty-five patients (12 and 13 affected by SLE and RA, respectively) were enrolled into the study. The Toronto Alexithymia Scale-20 (TAS-20) was administered. PRL, hGH, IL-6 and TNF-alfa levels were measured by commercially available ELISA kits. Results: Alexithymia prevalence (TAS-20≥51) was 54% in RA and 42% in SLE patients. hGH serum levels were 3.1±4.2 and 1.1±0.9 IU/ml in SLE and RA, respectively. PRL concentration was 18.4±6.5 ng/ml and 14.2±4.0 ng/ml in SLE and RA patients, respectively (p=0.03). In RA group, TNF-alpha was 20±36.2 whereas in SLE it was 4.9±12.8 pg/ml (p=0.03); IL-6 serum concentrations were 24.4±25.1 and 2.9±5.4 pg/ml, in RA and SLE respectively (p=0.004). The serum level of hGH showed slight increase in alexithymic group (A) compared to non alexithymic group (NA) in both SLE and RA patients. PRL serum levels in SLE-A patients was 26.7±17.3 ng/ml while in SLE-NA patients was 12.4±3.3 ng/ml (p=0.04). In RA patients increased values of IL-6 and TNF-alpha were present in the A group compared to NA group (IL-6: 35.3±28 pg/mL vs 3.5±3.9 pg/mL, p=0.01; TNF-alpha: 34.7±39 pg/mL vs 3.1±3.4 pg/mL, p=0.01). Conclusions: In this preliminary results we found an high prevalence of alexithymia and a correlation between immunoendocrine parameters and alexhytimic features in SLE and RA, suggesting that an immunomodulatory pathway could influence this cognitive style in patients with autoimmune disorders. Other studies should contribute to find a common biological pathway linking alexithymia and autoimmunity

    Rapid Dopamine Signaling Differentially Modulates Distinct Microcircuits within the Nucleus Accumbens during Sucrose-Directed Behavior

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    The mesolimbic dopamine projection from the ventral tegmental area (VTA) to the nucleus accumbens (NAc) is critical in mediating reward-related behaviors, but the precise role of dopamine in this process remains unknown. We completed a series of studies to examine whether coincident changes occur in NAc cell firing and rapid dopamine release during goal-directed behaviors for sucrose and if so, to determine if the two are causally linked. We show that distinct populations of NAc neurons differentially encode sucrose-directed behaviors, and using a combined electrophysiology/electrochemistry technique, further show that it is at those locations that rapid dopamine signaling is observed. To determine causality, NAc cell firing was recorded during selective pharmacological inactivation of dopamine burst firing using the NMDA receptor antagonist, AP-5. We show that phasic dopamine selectively modulates excitatory but not inhibitory responses of NAc neurons during sucrose-seeking behavior. Thus, rapid dopamine signaling does not exert global actions in the NAc but selectively modulates discrete NAc microcircuits that ultimately influence goal-directed actions

    Model-Independent Searches for New Quarks at the LHC

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    New vector-like quarks can have sizable couplings to first generation quarks without conflicting with current experimental constraints. The coupling with valence quarks and unique kinematics make single production the optimal discovery process. We perform a model-independent analysis of the discovery reach at the Large Hadron Collider for new vector-like quarks considering single production and subsequent decays via electroweak interactions. An early LHC run with 7 TeV center of mass energy and 1 fb-1 of integrated luminosity can probe heavy quark masses up to 1 TeV and can be competitive with the Tevatron reach of 10 fb-1. The LHC with 14 TeV center of mass energy and 100 fb-1 of integrated luminosity can probe heavy quark masses up to 3.7 TeV for order one couplings.Comment: 37 pages, 11 figures, 7 table
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