40 research outputs found

    Kaluza-Klein gluons at 100 TeV: NLO corrections

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    We explore the reach of a 100 TeV proton collider to discover KK gluons in a warped extra dimension. These particles are templates for color adjoint vectors that couple dominantly to the top quark. We examine their production rate at NLO in the six-flavor m-ACOT scheme for a variety of reference models defining their coupling to quarks, largely inspired by the RS model of a warped extra dimension. In agreement with previous calculations aimed at lower energy machines, we find that the NLO corrections are typically negative, resulting in a KK-factor of around 0.7 (depending on the model) and with a residual scale dependence on the order of ±20%\pm 20\%, greater than the variation from the scale exhibited by the na\"{i}ve LO estimate.Comment: 33 pages, 5 figures, 2 table

    Role of anisotropy in the spin-dimer compound BaCuSi2O6

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    We present results of magnetisation and electron paramagnetic resonance experiments on the spin-dimer system BaCuSi2O6. Evidence indicates that the origin of anisotropic terms in the spin Hamiltonian is from magnetic dipolar interactions. Axial symmetry-breaking is on a very small energy scale of ~11 mK, confirming Bose Einstein condensation critical scaling over an extended temperature range in the vicinity of the quantum critical point.Comment: 4 pages, 4 figure

    Protophobic Fifth-Force Interpretation of the Observed Anomaly in \u3csup\u3e8\u3c/sup\u3eBe Nuclear Transitions

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    Recently a 6.8σ anomaly has been reported in the opening angle and invariant mass distributions of e+e− pairs produced in 8Be nuclear transitions. The data are explained by a 17 MeV vector gauge boson X that is produced in the decay of an excited state to the ground state, 8Be∗ → 8Be X, and then decays through X → e+e−. The X boson mediates a fifth force with a characteristic range of 12 fm and has millicharged couplings to up and down quarks and electrons, and a proton coupling that is suppressed relative to neutrons. The protophobic X boson may also alleviate the current 3.6σ discrepancy between the predicted and measured values of the muon’s anomalous magnetic moment

    Protophobic Fifth-Force Interpretation of the Observed Anomaly in \u3csup\u3e8\u3c/sup\u3eBe Nuclear Transitions

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    Recently a 6.8σ anomaly has been reported in the opening angle and invariant mass distributions of e+e− pairs produced in 8Be nuclear transitions. The data are explained by a 17 MeV vector gauge boson X that is produced in the decay of an excited state to the ground state, 8Be∗ → 8Be X, and then decays through X → e+e−. The X boson mediates a fifth force with a characteristic range of 12 fm and has millicharged couplings to up and down quarks and electrons, and a proton coupling that is suppressed relative to neutrons. The protophobic X boson may also alleviate the current 3.6σ discrepancy between the predicted and measured values of the muon’s anomalous magnetic moment

    SUSY_FLAVOR v2.5: a computational tool for FCNC and CP-violating processes in the MSSM

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    We present SUSY_FLAVOR version 2.5 - a Fortran 77 program that calculates low-energy flavor observables in the general RR-parity conserving MSSM. For a set of MSSM parameters as input, the code gives predictions for: 1. Electric dipole moments of the leptons and the neutron. 2. Anomalous magnetic moments (i.e. g2g-2) of the leptons. 3. Radiative lepton decays (μeγ\mu\to e\gamma and τμγ,eγ\tau\to \mu\gamma, e\gamma). 4. Rare Kaon decays (KL0π0νˉνK^0_L\to \pi^0\bar\nu\nu and K+π+νˉνK^+\to \pi^+ \bar\nu\nu). 5. Leptonic BB decays (Bs,dl+lB_{s,d}\to l^+ l^-, BτνB\to \tau \nu, BDτνB\to D \tau \nu and BDτνB\to D^\star \tau \nu). 6. Radiative BB decays (BXˉsγB\to\bar X_s \gamma). 7. Rare decays of top quark to Higgs boson (tch,uht\to ch,uh). 8. ΔF=2\Delta F=2 processes (Kˉ0K0\bar K^0-K^0, DˉD\bar D-D, BˉdBd\bar B_d-B_d and BˉsBs\bar B_s-B_s mixing). SUSY_FLAVOR performs the resummation of all chirally enhanced corrections, i.e. takes into account the effects enhanced by tanβ\tan\beta and/or large trilinear soft mixing terms to all orders in perturbation theory. All calculations are done using exact diagonalization of the sfermion mass matrices. Comparing to previous versions, in SUSY_FLAVOR v2.5 parameter initialization in SLHA2 format has been significantly generalized and simplified, so that program accepts without modifications most of the output files produced by other codes calculating MSSM spectra and processes. In addition, the routine calculating branching ratios for rare decays of top quark to Higgs boson has been included. The program can be obtained from www.fuw.edu.pl/susy_flavor.Comment: Updated from arXiv:1003.4260 [hep-ph] (SUSY_FLAVOR v1 manual), 61 pages; updated sections on modified user interface and on newly added processes. SUSY_FLAVOR code available at http://www.fuw.edu.pl/susy_flavo

    Goldstone Fermion Dark Matter

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    We propose that the fermionic superpartner of a weak-scale Goldstone boson can be a natural WIMP candidate. The p-wave annihilation of this `Goldstone fermion' into pairs of Goldstone bosons automatically generates the correct relic abundance, whereas the XENON100 direct detection bounds are evaded due to suppressed couplings to the Standard Model. Further, it is able to avoid indirect detection constraints because the relevant s-wave annihilations are small. The interactions of the Goldstone supermultiplet can induce non-standard Higgs decays and novel collider phenomenology.Comment: 25 pages, 6 figures. References added, minor typos corrected. Submitted to JHE

    Snowmass Theory Frontier Report

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    This report summarizes the recent progress and promising future directions in theoretical high-energy physics (HEP) identified within the Theory Frontier of the 2021 Snowmass Process.Comment: Contribution to the US Community Study on the Future of Particle Physics (Snowmass 2021), v2: fixed typo

    Dark sectors 2016 Workshop: community report

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    This report, based on the Dark Sectors workshop at SLAC in April 2016, summarizes the scientific importance of searches for dark sector dark matter and forces at masses beneath the weak-scale, the status of this broad international field, the important milestones motivating future exploration, and promising experimental opportunities to reach these milestones over the next 5-10 years
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