Fri·Nov 6, 2015Friday·November 6, 2015

1. 01*

   Same-Sign Dilepton Excesses and Vector-like Quarks

   Chuan-Ren Chen🇹🇼 · Hsin-Chia Cheng🇺🇸 · Ian Low🇺🇸

   Multiple analyses from ATLAS and CMS collaborations, including searches for ttH production, supersymmetric particles and vector-like quarks, observed excesses in the same-sign dilepton channel containing b-jets and missing transverse energy in the LHC Run 1 data. In the context of little Higgs theories with T parity, we explain these excesses using vector-like T-odd quarks decaying into a top quark, a W boson and the lightest T-odd particle (LTP). For heavy vector-like quarks, decay topologies containing the LTP have not been searched for at the LHC. The bounds on the masses of the T-odd quarks can be estimated in a simplified model approach by adapting the search limits for top/bottom squarks in supersymmetry. Assuming a realistic decay branching fraction, a benchmark with a 750 GeV T-odd b-prime quark is proposed. We also comment on the possibility to fit excesses in different analyses in a common framework.

   hep-phhep-exJHEP(2016)·7 citations
2. 02*

   Kinetically Modified Non-Minimal Higgs Inflation in Supergravity

   C. Pallis🇨🇾

   We consider models of chaotic inflation driven by the real parts of a conjugate pair of Higgs superfields involved in the spontaneous breaking of a grand unification symmetry at a scale assuming its supersymmetric value. We combine a superpotential, which is uniquely determined by applying a continuous R symmetry, with a class of logarithmic or semi-logarithmic Kahler potentials which exhibit a prominent shift-symmetry with a tiny violation, whose strengths are quantified by c- and c+ respectively. The inflationary observables provide an excellent match to the recent BICEP2/Keck Array and Planck results setting 3.5x10^-3<=r+-=c+/c-<=1/N where N=3 or 2 is the prefactor of the logarithm. Inflation can be attained for subplanckian inflaton values with the corresponding effective theories retaining the perturbative unitarity up to the Planck scale.

   hep-phastro-ph.COhep-thPRD(2015)·19 citations
3. 03*

   T-odd correlations from top-quark CEDM in lepton plus jets top-pair events

   Alper Hayreter🇹🇷 · German Valencia🇦🇺

   There exist several recent studies of the top-quark CEDM in the context of searching for CP violating signals in top-quark pair production at the LHC. Most of these studies constrain the CEDM either from deviations in the top-pair cross section from its standard model value, or from T-odd asymmetries in the dimuon channel. Motivated by ATLAS and CMS interest, we extend the study of T-odd asymmetries to the lepton plus jets channel. At the parton level, using MadGraph, we identify the most promising signals and their statistical sensitivity. We find that the signals with larger sensitivity to the CEDM require distinguishing between $b$ and $\bar{b}$ jets and propose a simple way to address this.

   hep-phPRD(2016)·24 citations
4. 04*

   The ATLAS Di-boson Excess Could Be an R-parity Violating Di-smuon Excess

   B. C. Allanach🇬🇧 · P. S. Bhupal Dev🇩🇪 · Kazuki Sakurai🇬🇧

   We propose a new possible explanation of the ATLAS di-boson excess: that it is due to heavy resonant slepton production, followed by decay into di-smuons. The smuon has a mass not too far from the W and Z masses, and so it is easily confused with W or Z bosons after its subsequent decay into di-jets, through a supersymmetry violating and R-parity violating interaction. Such a scenario is not currently excluded by other constraints and remains to be definitively tested in Run II of the LHC. Such light smuons can easily simultaneously explain the discrepancy between the measurement of the anomalous magnetic moment of the muon and the Standard Model prediction.

   hep-phhep-exPRD(2016)·19 citations
5. 05*

   The Quark Propagator in a Truncation Scheme beyond the Rainbow Approximation

   Hui-Feng Fu🇨🇳 · Qing Wang🇨🇳

   The quark propagator is studied under a truncation scheme beyond the rainbow approximation by dressing the quark-gluon vertex non-perturbatively. It is found that, in the chiral limit with dynamical symmetry breaking, the dynamical quark mass and the quark condensate are significantly enhanced due to the non-Abelian contribution arising from the three-gluon interaction compared to those under the rainbow approximation; and the critical strength of the dynamical chiral symmetry breaking is much lowered. The Abelian contribution is much smaller than the non-Abelian contribution. A technical issue on removing the ultraviolet divergences including the overlapping divergences is discussed.

   hep-phPRD(2016)·10 citations
6. 06*

   Chiral Nonet Mixing in $\pi K$ Scattering

   Amir H. Fariborz🇺🇸 · Esmaiel Pourjafarabadi🇮🇷 · Soodeh Zarepour🇮🇷 · S. Mohammad Zebarjad🇮🇷

   The underlying mixing of quark components of scalar mesons is probed in $\pi K$ scattering within a generalized linear sigma model that contains two scalar meson nonets and two pseudoscalar meson nonets (a quark-antiquark and a four-quark). In the leading order of this model, all free parameters have been previously fixed using the mass spectra and several low-energy parameters known from experiment and consistent predictions have been made. As other predictions of the model, in the present work the isospins $I$= 1/2, 3/2 and $J$=0 projection of $\pi K$ scattering amplitude (as well as phase shifts) are computed and compared with experiment. In the $I$=1/2 channel, it is shown that within the uncertainties of the model parameters a good agreement with experimental data up to an energy of about 1 GeV is obtained, whereas in the $I$=3/2 channel there is a better agreement with experiment which extends to about 1.4 GeV. The effect of final state interactions of $\pi K$ in the $I$=1/2 channel is approximated by the K-matrix method and the poles of the unitarized scattering amplitude are found. It is shown that the model predicts a light and broad kappa resonance with a mass and decay width of 670-770 MeV and 640-750 MeV consistent with other prior works. Moreover, the scattering lengths in the $I$=1/2, 3/2 are also computed and shown to qualitatively agree with experiment. The overall predictions presented here further support previous findings that the scalar mesons below and above 1 GeV have substantial underlying mixings and that those below 1 GeV have dominant four-quark substructures while those above 1 GeV are closer to conventional $P$-wave quark-antiquark states.

   hep-phPRD(2015)·17 citations
7. 07*

   Gauge-Higgs Grand Unification

   Yutaka Hosotani🇯🇵 · Naoki Yamatsu🇯🇵

   Gauge-Higgs grand unification is formulated. By extending $SO(5)\times U(1{)}_X$ gauge-Higgs electroweak unification, strong interactions are incorporated in $SO(11)$ gauge-Higgs unification in the Randall-Sundrum warped space. Quarks and leptons are contained in spinor and vector multiplets of $SO(11)$. Although the KK scale can be as low as $10$ TeV, proton decay is forbidden by a conserved fermion number in the absence of Majorana masses of neutrinos.

   hep-phhep-thPoS(2015)·7 citations
8. 08*

   More Higgses at the LHC and the Electroweak Phase Transition

   G. C. Dorsch🇩🇪 · S. J. Huber🇬🇧 · K. Mimasu🇬🇧 · J. M. No🇬🇧

   A cosmological first order electroweak phase transition could explain the origin of the cosmic matter-antimatter asymmetry. While it does not occur in the Standard Model, it becomes possible in the presence of a second Higgs doublet. In this context, we obtain the properties of the new scalars $H_0$, $A_0$ and $H^{\pm }$ leading to such a phase transition, showing that its key LHC signature would be the decay $A_0\to H_{0}Z$, and we analyze the promising LHC search prospects for this decay in the $\ell \ell b\bar{b}$ and $\ell \ell W^{+}{W}^{-}$ final states. Finally, we comment on the impact of the $A_0\to H_{0}Z$ decay on current LHC searches for $A_0$ decaying into SM particles.

   hep-ph0 citations
9. 09*

   Non-factorizable photonic corrections to resonant production and decay of many unstable particles

   Stefan Dittmaier🇩🇪 · Christopher Schwan🇩🇪

   Electroweak radiative corrections to the production of high-multiplicity final states with several intermediate resonances in most cases can be sufficiently well described by the leading contribution of an expansion about the resonance poles. In this approach, also known as pole approximation, corrections are classified into separately gauge-invariant factorizable and non-factorizable corrections, where the former can be attributed to the production and decay of the unstable particles on their mass shell. The remaining non-factorizable corrections are induced by the exchange of soft photons between different production and decay subprocesses. We give explicit analytical results for the non-factorizable photonic virtual corrections to the production of an arbitrary number of unstable particles at the one-loop level and, thus, deliver an essential building block in the calculation of next-to-leading-order electroweak corrections in pole approximation. The remaining virtual factorizable corrections can be obtained with modern automated one-loop matrix-element generators, while the evaluation of the corresponding real photonic corrections can be evaluated with full matrix elements by multi-purpose Monte Carlo generators. Our results can be easily modified to non-factorizable QCD corrections, which are induced by soft-gluon exchange.

   hep-phEPJC(2016)·38 citations
10. 10*

    Longitudinal momentum densities in transverse plane for nucleons

    Chandan Mondal🇮🇳

    We present a study of longitudinal momentum densities ($p^{+}\mathrm{densities}$) in the transverse impact parameter space for $u$ and $d$ quarks in both unpolarized and transversely polarized nucleons by taking a two dimensional Fourier transform of the gravitational form factors with respect to the momentum transfer in the transverse direction. The gravitational form factors are obtained by the second moments of GPDs. Here we consider the GPDs of two different soft-wall models in AdS/QCD correspondence.

    hep-phEPJC(2016)·22 citations
11. 11*

    Bounds on Neutrino-Scalar Yukawa Coupling

    P. S. Pasquini🇧🇷 · O. L. G. Peres🇧🇷

    General neutrino-scalar couplings appear in many extensions of Standard Model. We can probe these neutrino-scalar couplings by leptonic decay of mesons and from heavy neutrino search. Our analysis improves the present limits to $|g_e{|}^2<1.9\times 10^{-6}$ and $|g_{\mu }{|}^2<1.9\times 10^{-7}$ at 90\% C.L. for massless scalars. For massive scalars we found for the first time the constraints for $g_{\alpha }^2$ couplings to be $10^{-6}-10^{-1}$ respectively for scalar masses between below 1 MeV and for 300 MeV.

    hep-phPRD(2016)·90 citations
12. 12*

    A Clockwork Axion

    David E. Kaplan🇺🇸 · Riccardo Rattazzi🇨🇭

    We present a renormalizable theory of scalars in which the low energy effective theory contains a pseudo-Goldstone Boson with a compact field space of 2{\pi} F and an approximate discrete shift symmetry Z_Q with Q>>1, yet the number of fields in the theory goes as log(Q). Such a model can serve as a UV completion to models of relaxions and is a new source of exponential scale separation in field theory. While the model is local in `theory space', it appears to not have a continuum generalization (i.e., it cannot be a deconstructed extra dimension). Our framework shows that super-Planckian field excursions can be mimicked while sticking to renormalizable four-dimensional quantum field theory. We show that a supersymmetric extension is straightforwardly obtained and we illustrate possible UV completions based on a compact extra-dimension, where all global symmetries arise accidentally as a consequence of gauge invariance and 5D locality.

    hep-phhep-thPRD(2016)·380 citations
13. 13*

    Revisiting $B_s\to {\mu }^{+}{\mu }^{-}$ in the two-Higgs doublet models with $Z_2$ symmetry

    Xiao-Dong Cheng🇨🇳 · Ya-Dong Yang🇨🇳 · Xing-Bo Yuan🇰🇷

    We revisit the rare leptonic decay $B_s\to {\mu }^{+}{\mu }^{-}$ in the two-Higgs doublet models with a softly broken $Z_2$ symmetry, namely type-I, type-II, type-X and type-Y 2HDMs. We have derived the relevant full one-loop Wilson coefficients of the four 2HDMs from the recent calculation in the aligned two-Higgs doublet model by Li, Lu and Pich, which could be mapped to all the four 2HDMs for both large and small $\tan \beta$. It is found that, a new term associated with the soft $Z_2$ symmetry breaking parameter $M$ can be enhanced by ${\tan }^2\beta$ in the type-II 2HDM, which has not been considered in the literature. Imposing both theoretical and experimental constraints, we have renewed the bounds on the parameter spaces of the four 2HDMs. Different from our previous paper, however, we find that all the four 2HDMs give sizable and similar contributions to $\overline{\mathcal{B}}(B_s\to {\mu }^{+}{\mu }^{-})$ within the stringently restricted parameter spaces, but very tiny as regards the mass-eigenstate rate asymmetry ${\mathcal{A}}_{\Delta \Gamma }$; this makes it unfeasible to discriminate the four types of 2HDM with the correlations between the observables in $B_s\to {\mu }^{+}{\mu }^{-}$ decay.

    hep-phEPJC(2016)·26 citations
14. 14*

    Primordial trispectra and CMB spectral distortions

    Nicola Bartolo🇮🇹 · Michele Liguori🇮🇹 · Maresuke Shiraishi🇯🇵

    We study the $TT\mu$ bispectrum, generated by correlations between Cosmic Microwave Background temperature (T) anisotropies and chemical potential ($\mu$) distortions, and we analyze its dependence on primordial local trispectrum parameters $g_{\mathrm{NL}}$ and ${\tau }_{\mathrm{NL}}$. We cross-check our results by comparing the full bispectrum calculation with the expectations from a general physical argument, based on predicting the shape of $\mu$-T correlations from the couplings between short and long perturbation modes induced by primordial non-Gaussianity. We show that $both$ $g_{\mathrm{NL}}$ and ${\tau }_{\mathrm{NL}}$-parts of the primordial trispectrum source a non-vanishing $TT\mu$ signal, contrary to the $\mu \mu$ auto-correlation function, which is sensitive only to the ${\tau }_{\mathrm{NL}}$-component. A simple Fisher matrix-based forecast shows that a futuristic, cosmic-variance dominated experiment could in principle detect $g_{\mathrm{NL}}\sim 0.4$ and ${\tau }_{\mathrm{NL}}\sim 40$ using $TT\mu$.

    ↳ astro-ph.COgr-qchep-phhep-thJCAP(2016)·32 citations
15. 15*

    Induced Gravity I: Real Scalar Field

    Martin B Einhorn🇺🇸 · D R Timothy Jones🇺🇸

    We show that classically scale invariant gravity coupled to a single scalar field can undergo dimensional transmutation and generate an effective Einstein-Hilbert action for gravity, coupled to a massive dilaton. The same theory has an ultraviolet fixed point for coupling constant ratios such that all couplings are asymptotically free. However the catchment basin of this fixed point does not include regions of coupling constant parameter space compatible with locally stable dimensional transmutation. In a companion paper we will explore whether this more desirable outcome does obtain in more complicated theories with non-Abelian gauge interactions.

    ↳ hep-thgr-qchep-phJHEP(2016)·45 citations
16. 16*

    Generalised matter couplings in massive bigravity

    Scott Melville🇺🇸 · Johannes Noller🇬🇧

    We investigate matter couplings in massive bigravity. We find a new family of such consistent couplings, including and extending known consistent matter couplings, and we investigate their decoupling limits, ADM decompositions, Higuchi bounds and further aspects. We show that differences to previous known consistent couplings only arise beyond the ${\Lambda }_3$ decoupling limit and discuss the uniqueness of consistent matter couplings and how this is related to the so-called symmetric vielbein condition. Since we work in a vielbein formulation, these results easily generalise to multi-gravity.

    ↳ hep-thastro-ph.COgr-qchep-phJHEP(2016)·27 citations
17. 17*

    On calculating disconnected-type hadronic light-by-light scattering diagrams from lattice QCD

    Masashi Hayakawa🇯🇵 · Thomas Blum🇺🇸 · Norman Christ🇺🇸 · Taku Izubuchi🇺🇸 · Luchang Jin🇺🇸 · Christoph Lehner🇺🇸

    For reliable comparison of the standard model prediction to the muon g-2 with its experimental value, the hadronic light-by-light scattering (HLbL) contribution must be calculated by lattice QCD simulation. HLbL contribution has many types of disconnected-type diagrams. Here, we start with recalling the point that must be taken care of in every method to calculate them by lattice QCD, and present one concrete method called nonperturbative QED method.

    ↳ hep-lathep-phPoS(2016)·4 citations
18. 18*

    A Predictive Analytic Model for the Solar Modulation of Cosmic Rays

    Ilias Cholis🇺🇸 · Dan Hooper🇺🇸 · Tim Linden🇺🇸

    An important factor limiting our ability to understand the production and propagation of cosmic rays pertains to the effects of heliospheric forces, commonly known as solar modulation. The solar wind is capable of generating time and charge-dependent effects on the spectrum and intensity of low energy ($\text{lsim}$ 10 GeV) cosmic rays reaching Earth. Previous analytic treatments of solar modulation have utilized the force-field approximation, in which a simple potential is adopted whose amplitude is selected to best fit the cosmic-ray data taken over a given period of time. Making use of recently available cosmic-ray data from the Voyager 1 spacecraft, along with measurements of the heliospheric magnetic field and solar wind, we construct a time, charge and rigidity-dependent model of solar modulation that can be directly compared to data from a variety of cosmic-ray experiments. We provide a simple analytic formula that can be easily utilized in a variety of applications, allowing us to better predict the effects of solar modulation and reduce the number of free parameters involved in cosmic ray propagation models.

    ↳ astro-ph.SRastro-ph.HEhep-phphysics.space-phPRD(2016)·113 citations
19. 19*

    Heavy mesons in a hadronic medium: interaction and transport coefficients

    Juan M. Torres-Rincon🇫🇷 · Luciano M. Abreu🇧🇷 · Daniel Cabrera🇩🇪 · Olena Romanets🇳🇱 · Laura Tolos🇩🇪

    We review the recent results of heavy meson diffusion in thermal hadronic matter. The interactions of D and B-bar mesons with other hadrons (light mesons and baryons) are extracted from effective field theories based on chiral and heavy-quark symmetries. When these guiding principles are combined with exact unitarity, physical values of the cross sections are obtained. These cross sections (which contain resonant contributions) are used to calculate the drag and diffusion coefficients of heavy mesons immersed in a thermal and dense medium. The transport coefficients are computed using a Fokker-Planck reduction of the Boltzmann equation.

    ↳ nucl-thhep-phJ.Phys.Conf.Ser.(2016)·2 citations
20. 20*

    A New Method for Obtaining the Baryons Mass under the Killingbeck Plus Isotonic Oscillator Potentials

    Nasrin Salehi🇮🇷

    In this work, the spectrum of ground state and excited baryons (N, {\Delta}, , , and {\Omega} particles) has been investigated by using a non-relativistic quantum mechanics under the Killingbeck plus isotonic oscillator potentials. Using the Jacobi-coordinates, anzast method and generalized Gürsey Radicati (GR) mass formula the three body wave equation is solved to calculate the different states of the considered baryons. A comparison between our calculations and the available experimental data shows that the position of the Roper resonances of the nucleon, the ground states and the excited multiplets up to three GeV are in general well reproduced. Also one can conclude that; the interaction between the quark constituents of baryon resonances could be described adequately by using the combination of Killingbeck and isotonic oscillator potentials form.

    ↳ nucl-thhep-phAdv.High Energy Phys.(2016)·7 citations
21. 21*

    The general de Sitter supergravity component action

    Marjorie Schillo🇧🇪 · Ellen van der Woerd🇧🇪 · Timm Wrase🇦🇹

    In this paper we review the appearance and utility of a nilpotent chiral multiplet in the context of supergravity, string theory and cosmology. Coupling a nilpotent chiral superfield to supergravity, one obtains what is called pure dS supergravity, a supergravity theory without scalar degrees of freedom that naturally has de Sitter (dS) solutions, and in which supersymmetry is non-linearly realized. We extend previous results that couple this dS supergravity to chiral and vector multiplets and derive the most general supergravity action for a single nilpotent chiral multiplet coupled to supergravity and an arbitrary number of chiral and vector multiplets.

    ↳ hep-thgr-qchep-phFortsch.Phys.(2016)·48 citations
22. 22*

    Nonrelativistic Banks-Casher relation and random matrix theory for multi-component fermionic superfluids

    Takuya Kanazawa🇯🇵 · Arata Yamamoto🇯🇵

    We apply QCD-inspired techniques to study nonrelativistic N-component degenerate fermions with attractive interactions. By analyzing the singular-value spectrum of the fermion matrix in the Lagrangian, we derive several exact relations that characterize the spontaneous symmetry breaking U(1)xSU(N)$\to$Sp(N) through bifermion condensates. These are nonrelativistic analogues of the Banks-Casher relation and the Smilga-Stern relation in QCD. Non-local order parameters are also introduced and their spectral representations are derived, from which a nontrivial constraint on the phase diagram is obtained. The effective theory of soft collective excitations is derived and its equivalence to random matrix theory is demonstrated in the epsilon-regime. We numerically confirm the above analytical predictions in Monte Carlo simulations.

    ↳ cond-mat.quant-gashep-lathep-phPRD(2016)·2 citations
23. 23*

    Polarization Evolution of Early Optical Afterglows of Gamma-Ray Bursts

    Mi-Xiang Lan🇨🇳 · Xue-Feng Wu🇨🇳 · Zi-Gao Dai🇨🇳

    The central engine and jet composition of gamma-ray bursts (GRBs) remain mysterious. Here we suggest that observations on polarization evolution of early optical afterglows may shed light on these questions. We first study the dynamics of a reverse shock and a forward shock that are generated during the interaction of a relativistic jet and its ambient medium. The jet is likely magnetized with a globally large-scale magnetic field from the central engine. The existence of the reverse shock requires that the magnetization degree of the jet should not be high ($\sigma \le 1$), so that the jet is mainly composed of baryons and leptons. We then calculate the light curve and polarization evolution of an early optical afterglow, and find that when the polarization position angle changes by $90^{\circ }$ during the early afterglow, the polarization degree is zero for a toroidal magnetic field but is very likely to be non-zero for an aligned magnetic field. This result would be expected to provide a probe for the central engine of GRBs, because an aligned field configuration could originate from a magnetar central engine and a toroidal field configuration could be produced from a black hole via the Blandford-Znajek mechanism. Finally, for such two kinds of magnetic field configurations, we fit the observed data of the early optical afterglow of GRB 120308A equally well.

    ↳ astro-ph.HEhep-phApJ(2016)·35 citations
24. 24*

    XYZ Meson Spectroscopy

    Stephen Lars Olsen🇰🇷

    Many candidate multiquark mesons, i.e., mesons with substructures that are more complex than the quark-antiquark prescription that is in the textbooks, have recently been observed. Many of the most recently observed candidate states are electrically charged and have the same spin and parity, namely JP=1+. In this talk I give an overview of the current experimental situation and identify patterns among the recently discovered JP=1+ states, compare these patterns with expectations from proposed theoretical models, and the existence of additional, related states that might be accessible at current and future experiments. In addition, models that attribute the observed states to kinematically induced cusps are discussed.

    ↳ hep-exhep-phnucl-exPoS(2015)·23 citations
25. 25*

    Active Galactic Nuclei as High-Energy Neutrino Sources

    Kohta Murase🇺🇸

    Active galactic nuclei (AGN) are believed to be promising candidates of extragalactic cosmic-ray accelerators and sources, and associated high-energy neutrino and hadronic gamma-ray emission has been studied for many years. We review models of high-energy neutrino production in AGN and discuss their implications for the latest IceCube observation of the diffuse neutrino intensity.

    ↳ astro-ph.HEhep-phNeutrino Astronomy, pp.15-31 (2017)·69 citations
26. 26*

    Anisotropic Inflation and Cosmological Observations

    Razieh Emami (IPM, Institute for Advanced Study, Hong Kong U. Sci. Tech.)🇨🇳

    Recent observations opened up a new window on the inflationary model building. As it was firstly reported by the WMAP data, there may be some indications of statistical anisotropy on the CMB map, although the statistical significance of these findings are under debate. Motivated by these observations, people begun considering new inflationary models which may lead to statistical anisotropy. The simplest possible way to construct anisotropic inflation is to introduce vector fields. During the course of this thesis, we study models of anisotropic inflation and their observational implications such as power spectrum, bispectrum etc. Firstly we build a new model, which contains the gauge field which breaks the conformal invariance while preserving the gauge invariance. We show that in these kind of models, there can be an attractor phase in the evolution of the system when the back-reaction of the gauge field becomes important in the evolution of the inflaton field. We then study the cosmological perturbation theory in these kind of models. More specifically, we calculate the anisotropic corrections due to the presence of the vector field. We then generalize the separate universe formalism to our anisotropic set up and use it in some specific examples of anisotropic inflation. Finally, we connect the primordial anisotropies to the specific examples and to CMB observations. We calculate the TT, TE, TB, EB and BB correlation in the model of charged scalar field model and look for the unique signatures that the anisotropic inflation can have on the CMB map. Any future detection of these statistical anisotropies would rule out the isotropic FRW models.

    ↳ astro-ph.COhep-phhep-th22 citations
27. 27*

    MoEDAL: Seeking magnetic monopoles and more at the LHC

    Vasiliki A. Mitsou (the MoEDAL Collaboration)🇪🇸

    The MoEDAL experiment (Monopole and Exotics Detector at the LHC) is designed to directly search for magnetic monopoles and other highly ionising stable or metastable particles arising in various theoretical scenarios beyond the Standard Model. Its physics goals --largely complementary to the multi-purpose LHC detectors ATLAS and CMS-- are accomplished by the deployment of plastic nuclear track detectors combined with trapping volumes for capturing charged highly ionising particles and TimePix pixel devices for monitoring. This paper focuses on the status of the detectors and the prospects for LHC Run II.

    ↳ physics.ins-dethep-exhep-phPoS(2015)·7 citations
28. 28*

    Flux tubes at finite temperature

    Paolo Cea🇮🇹 · Leonardo Cosmai🇮🇹 · Francesca Cuteri🇮🇹 · Alessandro Papa🇮🇹

    The chromoelectric field generated by a static quark-antiquark pair, with its peculiar tube-like shape, can be nicely described, at zero temperature, within the dual superconductor scenario for the QCD confining vacuum. In this work we investigate, by lattice Monte Carlo simulations of the SU(3) pure gauge theory, the fate of chromoelectric flux tubes across the deconfinement transition. We find that, as the temperature is increased towards and above the deconfinement temperature $T_c$, the amplitude of the field inside the flux tube gets smaller, while the shape of the flux tube does not vary appreciably across deconfinement. This scenario with flux-tube "evaporation" above $T_c$ has no correspondence in ordinary (type-II) superconductivity, where instead the transition to the phase with normal conductivity is characterized by a divergent fattening of flux tubes as the transition temperature is approached from below. We present also some evidence about the existence of flux-tube structures in the magnetic sector of the theory in the deconfined phase.

    ↳ hep-lathep-phJHEP(2016)·49 citations
29. 29*

    Cosmological perturbation of Unimodular Gravity and General Relativity are identical

    Abhishek Basak🇮🇳 · Ophélia Fabre🇮🇳 · S. Shankaranarayanan🇮🇳

    Unimodular Gravity (UG) is a restricted version of General Relativity (GR) in which the determinant of the metric is a fixed function and the field equations are given by the trace-free part of the full Einstein equations. The background equations in UG and GR are identical. It was recently claimed that, the first order contribution in the temperature fluctuation of the Cosmic Microwave Background (CMB) in UG is different from GR. In this work, we calculate the first order perturbation equations in UG and show that the Sachs-Wolfe effect in UG, in terms of gauge invariant variables, is identical to GR. We also show that the second order perturbation equation of Mukhnanov-Sasaki variable in UG, is identical to GR. The only difference comes from the gauge choices due the constraint on the metric determinant. Hence, UG and GR are identical and indistinguishable in CMB data on large scales.

    ↳ gr-qcastro-ph.COhep-phGen.Rel.Grav.(2016)·31 citations
30. 30*

    Characteristic Size and Mass of Galaxies in the Bose-Einstein Condensate Dark Matter Model

    Jae-Weon Lee🇰🇷

    We study the characteristic length scale of galactic halos in the Bose-Einstein condensate (or scalar field) dark matter model. Considering the evolution of the density perturbation we show that the average background matter density determines the quantum Jeans mass and hence the spatial size of galaxies at a given epoch. In this model the minimum size of galaxies increases while the minimum mass of the galaxies decreases as the universe expands. The observed values of the mass and the size of the dwarf galaxies are successfully reproduced with the dark matter particle mass $m\simeq 5\times 10^{-22}eV$. The minimum size is about $6\times 10^{-3}\sqrt{m/H}{\lambda }_c$ and the typical rotation velocity of the dwarf galaxies is $O(\sqrt{H/m}$) c, where $H$ is the Hubble parameter and ${\lambda }_c$ is the Compton wave length of the particle. We also suggest that ultra compact dwarf galaxies are the remnants of the dwarf galaxies formed in the early universe.

    ↳ astro-ph.GAhep-phhep-thPLB(2016)·24 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.