Mon·Dec 17, 2018Monday·December 17, 2018

1. 01*

   Resonant heavy Higgs searches at the HL-LHC

   Amit Adhikary🇮🇳 · Shankha Banerjee🇬🇧 · Rahool Kumar Barman🇮🇳 · Biplob Bhattacherjee🇮🇳

   In this work, we show the importance of searches for heavy resonant scalars ($H$) and pseudoscalars ($A$). Taking cue from the present searches, we make projections for searches in an extended scalar sector at the high luminosity run of the Large Hadron Collider. We study the three most relevant search channels, \textit{i.e.}, $H\to hh,H/A\to t\bar{t}$ and $b\bar{b}H/A$. Upon studying multifarious final states for the resonant double Higgs production, we find that the $b\bar{b}\gamma \gamma$ ($\sigma (pp\to H\to hh)\in [81.27,14.45]$ fb for $m_H\in [300,600]$ GeV at 95\% C.L.) and $b\bar{b}b\bar{b}$ ($[5.4,2.5]$ fb for $m_H\in [800,1000]$ GeV at 95\% C.L.) channels are the most constraining. For the $b\bar{b}H$ channel, we can exclude $\sigma (pp\to b\bar{b}H)\in [22.2,3.7]$ fb for $m_H\in [300,500]$ GeV. Finally, we consider the phenomenological Minimal Supersymmetric Standard Model as an example and impose various present constraints and our future direct search-limits and obtain strong constraints on the $m_A-\tan \beta$ parameter space, where $m_A$ and $\tan \beta$ are respectively the mass of the pseudoscalar and the ratio of the vacuum expectation values of the two Higgs doublets. Assuming that the heavy Higgs boson decays only to Standard Model (SM) states, we find that the $H\to hh\to b\bar{b}\gamma \gamma$ ($H\to t\bar{t}$) channel excludes $\tan \beta$ as low as 4 ($m_A\in [400,800]$ GeV) at 95\% CL. This weakens up to $\sim 5.5$ when the $b\bar{b}H$ channel dominates. Upon allowing for non-SM decay modes, the limits weaken.

   hep-phhep-exJHEP(2019)·34 citations
2. 02*

   Neutrino damping in a fermion and scalar background

   José F. Nieves🇺🇸 · Sarira Sahu🇲🇽

   We consider the propagation of a neutrino in a background composed of a scalar particle and a fermion using a simple model for the coupling of the form $\lambda {\bar{f}}_R{\nu }_L\varphi$. In the presence of these interactions there can be damping terms in the neutrino effective potential and index of refraction. We calculate the imaginary part of the neutrino self-energy in this case, from which the damping terms are determined. The results are useful in the context of Dark Matter-neutrino interaction models in which the scalar and/or fermion constitute the dark-matter. The corresponding formulas for models in which the scalar particle couples to two neutrinos via a coupling of the form ${\lambda }^{(\nu \nu \varphi )}{\bar{\nu }}_R^c{\nu }_L\varphi$ are then obtained as a special case, which can be important also in the context of neutrino collective oscillations in a supernova and in the Early Universe hot plasma before neutrino decoupling. A particular feature of our results is that the damping term in a $\nu \varphi$ background is independent of the antineutrino-neutrino asymmetry in the background. Therefore, the relative importance of the damping term may be more significant if the neutrino-antineutrino asymmetry in the background is small, because the leading $Z$-exchange and $\varphi$-exchange contributions to the effective potential, which are proportional to the neutrino-antineutrino asymmetry, are suppressed in that case, while the damping term is not.

   hep-phastro-ph.HEPRD(2019)·9 citations
3. 03*

   Relaxing LHC constraints on the $W_R$ mass

   Mariana Frank🇨🇦 · Özer Özdal🇨🇦 · Poulose Poulose🇮🇳

   We study mass bounds of the $W_R$ gauge boson in generic left-right symmetric models. Assuming that the gauge bosons couple universally to quarks and leptons, we allow different gauge couplings $g_R\ne g_L$ and mass mixing, $V_{CKM}^L\ne V_{CKM}^R$ in the left and right sectors. Imposing constraints from collider experiments and $K^0$, $B_d$, $B_s$ physics, we investigate scenarios where $W_R$ is lighter, or heavier than the right handed neutrino ${\nu }_R$. In these scenarios, $W_R$ mass bounds can be considerably relaxed, while $Z_R$ mass bounds are much more stringent. In the case where $M_{W_R}\le M_{{\nu }_R}$, the experimental constraints come from $W_R\to tb$ and $W_R\to jj$ channels, while if $M_{W_R}\ge M_{{\nu }_R}$, the dominant constraints come from $W_R\to \ell \ell jj$. The observed (expected) limits in the two-dimensional ($M_{W_R}$, $M_{{\nu }_R}$) mass plane excluded at 95\% confidence level extend to approximately $M_{W_R}$= 3.1 (3.3) TeV in the $ee$ channel and 3.3 (3.4) TeV in the ($\mu \mu$) channel, for a large range of right-handed neutrino masses up to $M_{{\nu }_R}$= 2.1 (2.1) TeV in the $ee$ channel and 2.6 (2.5) in the ($\mu \mu$) channel, representing a significant relaxation of the mass bounds.

   hep-phPRD(2019)·20 citations
4. 04*

   KeV Scale Frozen-in Self-Interacting Fermionic Dark Matter

   Haipeng An🇨🇳 · Ran Huo🇺🇸 · Wanqiang Liu🇨🇳

   We present a model in which the dark matter particle is frozen-in at MeV scale. In this model, the mediator between the standard model sector and the dark sector can automatically provide a self-interaction for dark matter. The interaction strength is naturally to be the in the region in favor of the cluster mass deficit anomaly. Due to the self-scattering, the Lyman-$\alpha$ constraint can be relaxed to $m_D\gtrsim 2$ keV. In this region the self-interaction and the Fermi pressure both play roles on forming a dark matter core at the center of the dwarf galaxies.

   hep-phastro-ph.GA9 citations
5. 05*

   The long road from Regge poles to the LHC

   Vittorio Del Duca🇨🇭 · Lorenzo Magnea🇮🇹

   The Regge limit of gauge-theory amplitudes and cross sections is a powerful theory tool for the study of fundamental interactions. It is a vast field of research, encompassing perturbative and non-perturbative dynamics, and ranging from purely theoretical developments to detailed phenomenological applications. It traces its origins to the proposal of Tullio Regge, almost sixty years ago, to study scattering phenomena in the complex angular momentum plane. In this very brief contribution, we look back to the early days of Regge theory, and follow a few of the many strands of its development, reaching to present day applications to scattering amplitudes in non-abelian gauge theories.

   hep-phhep-th8 citations
6. 06*

   Schwinger pair production and string breaking in non-Abelian gauge theory from real-time lattice improved Hamiltonians

   D. Spitz🇩🇪 · J. Berges🇩🇪

   Far-from-equilibrium dynamics of SU(2) gauge theory with Wilson fermions is studied in 1+1 space-time dimensions using a real-time lattice approach. Lattice improved Hamiltonians are shown to be very efficient in simulating Schwinger pair creation and emergent phenomena such as plasma oscillations. As a consequence, significantly smaller lattices can be employed to approach continuum physics in the infinite-volume limit as compared to unimproved implementations. This allows us to compute also higher-order correlation functions including four fermion fields, which give unprecedented insights into the real-time dynamics of the fragmentation process of strings between fermions and antifermions.

   hep-phhep-lathep-thnucl-thPRD(2019)·30 citations
7. 07*

   Momentum Space Topology and Non-Dissipative Currents

   M.A.Zubkov🇮🇱 · Z.V.Khaidukov🇷🇺 · R.A.Abramchuk🇷🇺

   Relativistic heavy ion collisions represent an arena for the probe of various anomalous transport effects. Those effects, in turn, reveal the correspondence between the solid state physics and the high energy physics, which share the common formalism of quantum field theory. It may be shown that for the wide range of {field-theoretic} models, the response of various nondissipative currents to the external gauge fields is determined by the momentum space topological invariants. Thus, the anomalous transport appears to be related to the investigation of momentum space topology -- the approach developed earlier mainly in the condensed matter theory. Within this methodology we analyse systematically the anomalous transport phenomena, which include, in particular, the anomalous quantum Hall effect, the chiral separation effect, the chiral magnetic effect, the chiral vortical effect and the rotational Hall effect.

   hep-phUniverse(2018)·7 citations
8. 08*

   One-loop QCD contributions to differential cross-sections for Higgs production at N${}^3$LO

   Charalampos Anastasiou🇨🇭 · Caterina Specchia🇨🇭

   We present one-loop contributions to the fully differential Higgs boson gluon-fusion cross-section for Higgs production via gluon fusion. Our results constitute a necessary ingredient of a complete N${}^3$LO determination of the cross-section. We perform our computation using a subtraction method for the treatment of soft and collinear singularities. We identify the infrared divergent parts in terms of universal splitting and eikonal functions, and demonstrate how phase-space integrations yield poles (up to $1/{ϵ}^6$ ) in the dimensional regulator $ϵ=(4-d)/2$. We compute the coefficients of the $ϵ$ expansion, including the finite part numerically. As a demonstration of our numerical implementation, we present the corrections at N${}^3$LO due to one-loop amplitudes in the rapidity and transverse momentum of the Higgs boson.

   hep-phJHEP(2019)·5 citations
9. 09*

   A Higgs Boson at 96 GeV?!

   S. Heinemeyer🇪🇸 · T. Stefaniak🇩🇪

   We briefly summarize some searches for Higgs bosons with a mass of m_phi <= 110 GeV at LEP and the LHC. We discuss a possible signal in the diphoton decay mode at m_phi = 96 GeV as reported by CMS, together with a 2 sigma hint in the bb final state at LEP. We briefly review possible interpretation of such a new particle in various BSM models. We focus on possible explanations as reported within the NMSSM and the munuSSM. Conclusions for future collider projects are briefly outlined.

   hep-phPoS(2019)·30 citations
10. 10*

    Non-standard interactions in ${\tau }^{-}\to ({\pi }^{-}\eta ,{\pi }^{-}{\pi }^0){\nu }_{\tau }$ decays

    G. López Castro🇲🇽

    Originally thought as clean processes to study the hadronization of the weak currents, semileptonic tau lepton decays can be useful to set constraints on non-standard (NS) weak interactions. In this talk we summarize our recent studies on the effects of NS interactions in ${\tau }^{-}\to ({\pi }^{-}{\pi }^0,{\pi }^{-}\eta ){\nu }_{\tau }$ decays. We find that experimental data on these decays provide strong constraints on NS scalar and tensor interactions, respectively. Further improved measurements at Belle II and a better knowledge of necessary tensor and scalar form factors will allow to set limits on these NS interactions that are similar or better to contraints obtained from other low-energy processes.

    hep-phSciPost Phys.Proc.(2019)·7 citations
11. 11*

    Top-quark flavor-changing $tqZ$ couplings and rare $\Delta F=1$ processes

    Chuan-Hung Chen🇹🇼 · Takaaki Nomura🇰🇷

    We model-independently study the impacts of anomalous $tqZ$ couplings ($q=u,c$), which lead to the $t\to qZ$ decays, on low energy flavor physics. It is found that the $tuZ$-coupling effect can significantly affect the rare $K$ and $B$ decays, whereas the $tcZ$-coupling effect is small. Using the ATLAS's branching ratio (BR) upper bound of $BR(t\to uZ)<1.7\times 10^{-4}$, the influence of the anomalous $tuZ$-coupling on the rare decays can be found as follows: (a) The contribution to the Kaon direct CP violation can be up to $Re({ϵ}^{\prime }/ϵ)\lesssim 0.8\times 10^{-3}$; (b) $BR(K^{+}\to {\pi }^{+}\nu \bar{\nu })\lesssim 12\times 10^{-11}$ and $BR(K_L\to {\pi }^0\nu \bar{\nu })\lesssim 7.9\times 10^{-11}$; (c) the BR for $K_S\to {\mu }^{+}{\mu }^{-}$ including the long-distance effect can be enhanced by $11\%$ with respect to the standard model result, and (d) $BR(B_d\to {\mu }^{+}{\mu }^{-})\lesssim 1.97\times 10^{-10}$. In addition, although $Re({ϵ}^{\prime }/ϵ)$ cannot be synchronously enhanced with $BR(K_L\to {\pi }^0\nu \bar{\nu })$ and $BR(K_S\to {\mu }^{+}{\mu }^{-})$ in the same region of the CP-violating phase, the values of $Re({ϵ}^{\prime }/ϵ)$, $BR(K^{+}\to {\pi }^{+}\nu \bar{\nu })$, and $BR(B_d\to {\mu }^{+}{\mu }^{-})$ can be simultaneously increased.

    hep-phhep-exEPJC(2019)·5 citations
12. 12*

    Probing pseudo-Goldstone dark matter at the LHC

    Katri Huitu🇫🇮 · Niko Koivunen🇫🇮 · Oleg Lebedev🇫🇮 · Subhadeep Mondal🇫🇮 · Takashi Toma🇯🇵

    Pseudo-Goldstone dark matter coupled to the Standard Model via the Higgs portal offers an attractive framework for phenomenologically viable pseudo-scalar dark matter. It enjoys natural suppression of the direct detection rate due to the vanishing of the relevant (tree level) Goldstone boson vertex at zero momentum transfer, which makes light WIMP-like dark matter consistent with the strong current bounds. In this work, we explore prospects of detecting pseudo-Goldstone dark matter at the LHC, focusing on the vector boson fusion (VBF) channel with missing energy. We find that, in substantial regions of parameter space, relatively light dark matter ($m_{\chi }<100$ GeV) can be discovered in the high luminosity run as long as it is produced in decays of the Higgs-like bosons.

    hep-phPRD(2019)·60 citations
13. 13*

    ${\Omega }_c$ excited states: a molecular approach with heavy-quark spin symmetry

    Laura Tolos🇩🇪 · Rafael Pavao🇪🇸 · Juan Nieves🇪🇸

    The LHCb Collaboration has recently discovered five excited ${\Omega }_c$ states with masses between 3 and 3.1 GeV, four of them corroborated by the Belle Collaboration. We analyse the dynamical generation of these states within a molecular baryon-meson model that is consistent with both chiral and heavy-quark spin symmetries. Earlier predictions within this model found five ${\Omega }_c$ states with masses below 3 GeV. Thus, in order to study the possible identification of any of these states with the experimental ones in the correct energy region, we explore two different regularization schemes, that is, a modified regularization subtraction method and a cutoff regularization scheme. We find that at least three of the dynamically generated states can be identified with the experimental ones and have spin-parity $J=1/2^{-}$ or $J=3/2^{-}$

    hep-phnucl-exnucl-thJPS Conf.Proc.(2019)·2 citations
14. 14*

    Direct and indirect probes of Goldstone dark matter

    Tommi Alanne🇩🇪 · Matti Heikinheimo🇫🇮 · Venus Keus🇫🇮 · Niko Koivunen🇫🇮 · Kimmo Tuominen🇫🇮

    There exists a general model framework where dark matter can be a vanilla WIMP-like thermal relic with a mass of $\mathcal{O}$(100 GeV), but it still escapes direct detection. This happens, if the dark matter particle is a Goldstone boson whose scattering with ordinary matter is suppressed at low energy due to momentum-dependent interactions. We outline general features of this type of models and analyse a simple realization of these dynamics as a concrete example. In particular, we show that although direct detection of this type of dark matter candidate is very challenging, the indirect detection can already provide relevant constraints. Future projections of the indirect-detection experiments allow for even more stringent exclusion limits and can rule out models of this type.

    hep-phPRD(2019)·39 citations
15. 15*

    Quark and Gluon Jet Energy Loss

    Liliana Apolinário🇵🇹 · João Barata🇪🇸 · José Guilherme Milhano🇵🇹

    We present a study of the relative energy loss of quark and gluon jets that traverse a weakly-coupled medium. The study is carried out with the jet quenching Monte-Carlo event generator JEWEL which has been validated for a large set of jet observables. We find that the relative energy loss of quark and gluon jets approaches a constant value at large jet energy and that value is significantly larger (closer to 1) than the single parton expectation of $C_F/C_A$. Within JEWEL quark and gluon jets lose energy similarly.

    hep-phPoS(2018)·0 citations
16. 16*

    Instanton Triggered Chiral Symmetry Breaking, the U(1) Problem and a Possible Solution to the Strong CP Problem

    William A. Bardeen🇺🇸

    We argue that instantons play a crucial role in triggering the spontaneous breaking of chiral symmetry in the physics of the three light quarks in quantum chromodynamics. However, instantons may also play an essential role in our understanding of the suppression of CP violation in the strong interactions. We revive the possibility that the bare mass of the up quark is identically zero and the apparent small up quark mass is generated by the effective quark dynamics associated with instantons. In this case, the strong CP phase becomes unobservable and there is no strong CP violation.

    hep-phhep-th8 citations
17. 17*

    ${ϵ}^{\prime }/ϵ$-2018: A Christmas Story

    Andrzej J. Buras🇩🇪

    I was supposed to review the status of ${ϵ}^{\prime }/ϵ$ both at the CKM Workshop in September in Heidelberg and recently at the Discrete 2018 Conference in Vienna. Unfortunately I had to cancel both talks for family reasons. My main goal in these talks was to congratulate NA48 and KTeV collaborations for the discovery of new sources of CP violation through their heroic efforts to measure the ratio ${ϵ}^{\prime }/ϵ$ in the 1980s and 1990s with final results presented roughly 16 years ago. As I will not attend any other conferences this year I will reach this goal in this writing. In this context I will give arguments, why I am convinced about the presence of new physics in ${ϵ}^{\prime }/ϵ$ on the basis of my work with Jean-Marc Gerard within the context of the Dual QCD (DQCD) approach and why RBC-UKQCD collaboration and in particular Chiral Perturbation Theory practitioners are still unable to reach this conclusion. I will demonstrate that even in the presence of pion loops, as large as advocated recently by Gilbert and Pich, the value of ${ϵ}^{\prime }/ϵ$ is significantly below the data, when the main non-factorizable QCD dynamics at long distance scales, represented in DQCD by {the meson evolution}, is taken into account. As appriopriate for a Christmas story, I will prophesy the final value of ${ϵ}^{\prime }/ϵ$ within the SM, which should include in addition to the correct matching between long and short distance contributions, isospin breaking effects, NNLO QCD corrections to both QCD penguin and electroweak penguin contributions and final state interactions. Such final SM result will probably be known from lattice QCD only in the middle of 2020s, but already in 2019 we should be able to see some signs of NP in the next result on ${ϵ}^{\prime }/ϵ$ from RBC-UKQCD.

    hep-phhep-exhep-lat14 citations
18. 18*

    Jet production in charged-current deep-inelastic scattering to third order in QCD

    T. Gehrmann🇨🇭 · J. Niehues🇬🇧 · A. Huss🇨🇭 · A. Vogt🇬🇧 · D. M. Walker🇬🇧

    The production of jets in charged-current deep-inelastic scattering (CC DIS) probes simultaneously the strong and the electroweak sectors of the Standard Model; its measurement provides important information on the quark flavour structure of the proton. We compute third-order (N3LO) perturbative QCD corrections to this process, fully differential in the jet and lepton kinematics. We observe a substantial reduction in the theory uncertainty, to sub-percent level throughout the relevant kinematical range, thus enabling precision phenomenology with jet observables.

    hep-phPLB(2019)·45 citations
19. 19*

    Probing spectral properties of the QGP with real-time lattice simulations

    Kirill Boguslavski🇫🇮 · Aleksi Kurkela🇨🇭 · Tuomas Lappi🇫🇮 · Jarkko Peuron🇮🇹

    We present a new method to obtain spectral properties of a non-Abelian gauge theory in the region where occupation numbers are high. The method to measure the (single-particle) spectral function is based on linear response theory and classical-statistical lattice simulations. Although we apply it to a system far from equilibrium in a self-similar regime, the extracted spectral function can be understood within the hard thermal loop (HTL) formalism and can thus be connected to thermal equilibrium at high temperatures. This allows us to obtain quantities like the lifetime of quasiparticles that are beyond the leading order and difficult to compute within HTL. The approach has the potential to measure transport coefficients, to study the earliest stages of heavy-ion collisions in a controlled way and it can be employed beyond the range of validity of HTL.

    hep-phhep-latPoS(2018)·0 citations
20. 20*

    Exploring axial $U(1)$ restoration in a modified 2+1 flavor Polyakov quark meson model

    Suraj Kumar Rai🇮🇳 · Vivek Kumar Tiwari🇮🇳

    We report on the $U_A(1)$ symmetry restoration resulting due to temperature dependence of the coefficient c(T) for the Kobayashi-Maskawa-'t Hooft determinant (KMT) term in a modified 2+1 flavor Polyakov loop quark meson model having fermionic vacuum correction term (PQMVT).Temperature dependence of KMT coupling c(T) drives the non-strange condensate melting to significantly smaller temperatures in comparison to the constant c case.Further due to c(T), $m_{{\eta }^{\prime }}$ decreases from its vacuum value by 220 MeV near T=176 MeV after the chiral transition ($T_c^{\chi }=154.9$ MeV).This is similar to the ${\eta }^{\prime }$ in-medium mass drop of at least 200 MeV as reported by Csorgo and Vertesi in Ref (Phys Rev Lett 105:182301,2010; Phys Rev C 83:054903,2011), as an experimental signature of the effective restoration of $U_A(1)$ symmetry. The pseudoscalar mixing angle ${\theta }_p$ achieves anti-ideal mixing in the influence of c(T). The $\eta$ meson becomes light quark system (${\eta }_{NS}$) at T=176 MeV and changes its identity with ${\eta }^{\prime }$ meson which becomes strange quark system (${\eta }_S$). The degenerated temperature variations of $\sigma$, $\pi$ meson masses merges with the temperature variations of the masses of degenerated $a_0$, $\eta$ mesons near 275 MeV. It means that for c(T) when $m_{\sigma }=400$ MeV, the $U_A(1)$ restoration takes place at 1.75 $T_c^{\chi }$=275 MeV.

    hep-phnucl-thEur.Phys.J.Plus(2020)·17 citations
21. 21*

    Polarized backgrounds of relic gravitons

    Massimo Giovannini🇨🇭

    The polarizations of the tensor modes of the geometry evolving in cosmological backgrounds are treated as the components of a bispinor whose dynamics follows from an appropriate gauge-invariant action. This novel framework bears a close analogy with the (optical) Jones calculus and leads to a compact classification of the various interactions able to polarize the relic gravitons.

    ↳ gr-qcastro-ph.COhep-phhep-thPRD(2019)·10 citations
22. 22*

    Hair loss in parity violating gravity

    Pratik Wagle🇺🇸 · Nicolas Yunes🇺🇸 · David Garfinkle🇺🇸 · Lydia Bieri🇺🇸

    The recent detection of gravitational waves by the LIGO/VIRGO collaboration has allowed for the first tests of Einstein's theory in the extreme gravity regime, where the gravitational interaction is simultaneously strong, non-linear and dynamical. One such test concerns the rate at which the binaries inspiral, or equivalently the rate at which the gravitational wave frequency increases, which can constrain the existence of hairy black holes. This is because black holes with scalar hair typically excite dipole radiation, which in turn leads to a faster decay rate and frequency chirping. In this paper, we present a mathematical proof that scalar hair is not sourced in vacuum, spherically symmetric spacetimes when considering extensions of Einstein's theory that break parity in gravity, focusing on dynamical Chern-Simons theory as a particular toy model. This result implies that the observational confirmation of the baldness of black holes cannot be used to constrain parity violation in gravity, unless the black holes observed are also spinning.

    ↳ gr-qcastro-ph.HEhep-phhep-thClass.Quant.Grav.(2019)·27 citations
23. 23*

    Confinement of quarks in higher representations in view of dual superconductivity

    Akihiro Shibata🇯🇵 · Ryutaro Matsudo🇯🇵 · Seikou Kato🇯🇵 · Kei-Ichi Kondo🇯🇵

    Dual superconductor picture is one of the most promising scenarios for quark confinement. We have proposed a new formulation of Yang-Mills theory on the lattice so that the so-called restricted field obtained from the gauge-covariant decomposition plays the dominant role in quark confinement. This framework improves the Abelian projection in the gauge-independent manner. For quarks in the fundamental representation, we have demonstrated some numerical evidences for the dual superconductivity. However, it is known that the expected behavior of the Wilson loop in higher representations cannot be reproduced if the restricted part of the Wilson loop is extracted by adopting the Abelian projection or the field decomposition naively in the same way as in the fundamental representation. In this talk, therefore, we focus on confinement of quarks in higher representations. By virtue of the non-Abelian Stokes theorem for the Wilson loop operator, we propose suitable operators constructed from the restricted field only in the fundamental representation to reproduce the correct behavior of the original Wilson loop in higher representations. Moreover, we perform lattice simulations to measure the static potential for quarks in higher representations using the proposed operators. We find that the proposed operators well reproduce the expected behavior of the original Wilson loop average, which overcomes the problem that occurs in naively applying Abelian-projection to the Wilson loop operator for higher representations.

    ↳ hep-lathep-phPoS(2018)·1 citation
24. 24*

    Leptohadronic blazar models applied to the 2014-15 flare of TXS 0506+056

    Xavier Rodrigues🇩🇪 · Shan Gao🇩🇪 · Anatoli Fedynitch🇩🇪 · Andrea Palladino🇩🇪 · Walter Winter🇩🇪

    We investigate whether the emission of neutrinos observed in 2014-15 from the direction of the blazar TXS 0506+056 can be accommodated with leptohadronic multi-wavelength models of the source commonly adopted for the 2017 flare. While multi-wavelength data during the neutrino flare are sparse, the large number of neutrino events ($13\pm 5$) challenges the missing activity in gamma rays. We illustrate that two to five neutrino events during the flare can be explained with leptohadronic models of different categories: a one-zone model, a compact core model, and an external radiation field model. If, however, significantly more events were to be accommodated, the predicted multi-wavelength emission levels would be in conflict with observational X-ray constraints, or with the high-energy gamma ray fluxes observed by the Fermi LAT, depending on the model. For example, while the external radiation field model can predict up to five neutrino events without violating X-ray constraints, the absorption of high-energy gamma rays is in minor tension with data. We therefore do not find any model that can simultaneously explain the high event number quoted by IceCube and the (sparse) electromagnetic data during the neutrino flare.

    ↳ astro-ph.HEhep-phApJL(2019)·158 citations
25. 25*

    Nucleon in a periodic magnetic field: Finite-volume aspects

    Andria Agadjanov🇩🇪 · Ulf-G. Meißner🇩🇪 · Akaki Rusetsky🇩🇪

    The paper presents an extension and a refinement of our previous work on the extraction of the doubly virtual forward Compton scattering amplitude on the lattice by using the background field technique, Phys. Rev. D 95, 031502 (2017) (arXiv:1610.05545). The zero frequency limit for the periodic background field is discussed, in which the well-known result is reproduced. Further, an upper limit for the magnitude of the external field is established for which the perturbative treatment is still possible. Finally, the framework is set for the evaluation of the finite-volume corrections allowing for the analysis of upcoming lattice results.

    ↳ hep-lathep-phPRD(2019)·10 citations
26. 26*

    Is the $H_0$ tension suggesting a 4th neutrino's generation?

    S. Carneiro🇧🇷 · P. C. de Holanda🇧🇷 · C. Pigozzo🇧🇷 · F. Sobreira🇧🇷

    Flavour oscillations experiments are suggesting the existence of a sterile, $4$th neutrino's generation with a mass of an eV order. This would mean an additional relativistic degree of freedom in the cosmic inventory, in contradiction with recent results from the Planck satellite, that have confirmed the standard value $N_{eff}\approx 3$ for the effective number of relativistic species. On the other hand, the Planck best-fit for the Hubble-Lemaître parameter is in tension with the local value determined with the Hubble Space Telescope, and adjusting $N_{eff}$ is a possible way to overcome such a tension. In this paper we perform a joint analysis of three complementary cosmological distance rulers, namely the CMB acoustic scale measured by Planck, the BAO scale model-independently determined by Verde {\it et al.}, and luminosity distances measured with JLA and Pantheon SNe Ia surveys. Two Gaussian priors were imposed to the analysis, the local expansion rate measured by Riess {\it et al.}, and the baryon density parameter fixed from primordial nucleosynthesis by Cooke {\it et al.}. For the sake of generality, two different models are used in the tests, the standard $\Lambda$CDM model and a generalised Chaplygin gas. The best-fit gives $N_{eff}\approx 4$ in both models, with a Chaplygin gas parameter slightly negative, $\alpha \approx -0.04$. The standard value $N_{eff}\approx 3$ is ruled out with $\approx 3\sigma$.

    ↳ astro-ph.COgr-qchep-phPRD(2019)·55 citations
27. 27*

    Brane gaugino condensate in 10d

    Yuta Hamada🇬🇷 · Arthur Hebecker🇩🇪 · Gary Shiu🇺🇸 · Pablo Soler🇩🇪

    We analyze the structure of gaugino interactions on D7-branes from a 10d perspective. This is essential if one wants to lift the standard 4d approach to type IIB moduli stabilization to 10d. In particular, a 10d picture has recently been used to raise concerns about the KKLT proposal for constructing de Sitter vacua, and to lend support to swampland conjectures against de Sitter. However, the analyses of brane gaugino condensation so far are plagued by UV divergences and do not include local 4-fermion terms. They also fail to reproduce the 4-fermion terms required by supergravity when compactified to four dimensions. Motivated by the structure of heterotic and Horava-Witten theories, we suggest an extension of the brane action by a particular 4-fermion operator that resolves the above problems. Crucially, the UV divergence is cancelled and the expected structure of the 4d effective action is reproduced. We believe that attempts at a 10d description of KKLT have to be reconsidered in this new light.

    ↳ hep-thastro-ph.COhep-phJHEP(2019)·83 citations
28. 28*

    ESPRESSO's Early Commissioning Results and Performance Related to Tests of Fundamental Constant Stability

    A. C. O. Leite · C. J. A. P. Martins · P. Molaro · S. Monai · C. S. Alves · T. A. Silva · the ESPRESSO Science Team

    ESPRESSO is a new high-resolution ultra-stable spectrograph for the VLT, which had its first light on Telescope on November 27th, 2017. The instrument is installed in the Combined Coudé Laboratory and linked to the 4 Units of Telescope through optical Coudé Trains, being the first spectrograph able to collect the light from the 4 UTs simultaneously. One of the key science goals of the instrument is to test the stability of nature's fundamental couplings with unprecedented resolution and stability. ESPRESSO will allow to eliminate current known systematics and test the claim by Webb et al 2012 of a spatial dipole in the variation of the fine-structure constant. These improved results (either null or variation detections) will put strong constraints on a range of cosmological and particle physics parameters.

    ↳ astro-ph.IMgr-qchep-ph2 citations
29. 29*

    Confinement/deconfinement phase transition in SU(3) Yang-Mills theory and non-Abelian dual Meissner effect

    Akihiro Shibata🇯🇵 · Seikou Kato🇯🇵 · Kei-Ichi Kondo🇯🇵

    The dual superconductivity is a promising mechanism of quark confinement. In the preceding works, we have given a non-Abelian dual superconductivity picture for quark confinement, and demonstrated the numerical evidences on the lattice. In this talk, we focus on the the confinement and deconfinement phase transition at finite temperature in view of the dual superconductivity. By using our new formulation of lattice Yang-Mills theory and numerical simulations on the lattice, we extract the dominant mode for confinement by decomposing the Yang-Mills field, and we investigate the Polyakov loop average, static quark potential, chromoelectric flux, and induced monopole current for both Yang-Mills field and decomposed restricted field in both confinement and deconfinement phase at finite temperature. We further discuss the role of the chromomagnetic monopole in the confinement/deconfinement phase transition.

    ↳ hep-lathep-ph3 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.