Wed·Dec 20, 2017Wednesday·December 20, 2017

1. 01*

   Gauge and Yukawa coupling beta functions of two-Higgs-doublet models to three-loop order

   Florian Herren🇩🇪 · Luminita Mihaila🇩🇪 · Matthias Steinhauser🇩🇪

   We compute the beta functions for the three gauge couplings and the Yukawa matrices of a general two-Higgs-doublet model in the modified minimal subtraction scheme to three loops. The calculations are performed using Lorenz gauge in the unbroken phase. We discuss in detail the occurence of poles in anomalous dimensions and propose practical prescriptions to avoid them. We provide explicit results for the often used ${\mathbb{Z}}_2$-symmetric versions of the two-Higgs-doublet model of type I, II, X and Y. Furthermore, we provide the first independent cross-check of the three-loop Yukawa coupling beta functions of the Standard Model.

   hep-phPRD(2018)·45 citations
2. 02*

   Perspectives on the detection of supersymmetric Dark Matter

   Wim de Boer ((1) Karlsruhe Institute of Technology, Karlsruhe, Germany)🇩🇪

   Up to now searches for Dark Matter (DM) detection have not been successful, either because our paradigm in how DM signals should look like are wrong or the detector sensitivity is still too low in spite of the large progress made in recent years. We discuss both possibilities starting with what we know about DM from cosmology and why Supersymmetry provides such an interesting paradigm for cosmology and particle physics in order to appreciate what it means to give up this paradigm. In addition, we compare the predicted cross sections for direct and indirect DM detection with observations with emphasis on the latest developments. Especially, we discuss the possible origins of the two hotly debated candidates for a DM annihilation signal, namely the positron excess and the Fermi GeV excess, which are unfortunately incompatible with each other and more mundane astrophysical explanations exist.

   hep-phastro-ph.COastro-ph.GAEPJ Web Conf.(2018)·1 citation
3. 03*

   Massive Neutrinos: Phenomenological and Cosmological Consequences

   Yuber F. Perez-Gonzalez🇧🇷

   In this thesis we will address three different phenomena related to neutrino physics: mass models, detection of the cosmic neutrino background and the neutrino background in Dark Matter searches, considering the different characteristics in each case. In the study of neutrino mass models, we will consider models for both Majorana and Dirac neutrinos; specifically, we will probe the neutrinophilic two-Higgs-doublet model. Regarding the detection of relic neutrinos, we will analyse the consequences of the existence of physics beyond the Standard Model in the capture rate by tritium. Finally, we will scrutinize the impact of neutrinos in Direct Detection searches of Weakly Interacting Massive Particles (WIMP) including Standard Model plus additional interactions in the form of simplified models.

   hep-ph4 citations
4. 04*

   The T2HKK Experiment and Non-Standard Interaction

   Monojit Ghosh🇯🇵 · Osamu Yasuda🇯🇵

   In this work we study the the sensitivity of the T2HKK experiment to probe non-standard interaction in neutrino propagation. As this experiment will be statistically dominated due to its large detector volume and high beam-power, it is expected that the sensitivity will be affected by systematics. This motivates us to study the effect of systematics in probing the non-standard interaction. We also compare our results with the other future proposed experiments i.e., T2HK, HK and DUNE.

   hep-ph0 citations
5. 05*

   Parameter degeneracy and hierarchy sensitivity of NO$\nu$A in presence of sterile neutrino

   Monojit Ghosh🇯🇵 · Shivani Gupta🇦🇺 · Zachary M. Matthews🇦🇺 · Pankaj Sharma🇦🇺 · Anthony G. Williams🇦🇺

   The first hint of neutrino mass hierarchy is expected to come from the NO$\nu$A experiment in Fermilab as the present best-fit parameter space i.e., normal hierarchy and ${\delta }_{CP}=-90^{\circ }$ is the favourable parameter space for NO$\nu$A where there is no degeneracy. But this situation may change if the standard three flavour framework is not complete and there is existence of new physics. In this work we consider the presence of an extra light sterile neutrino at the eV scale and study the new degeneracies which are absent in the standard three flavour framework. We also study the effect of these new degeneracies on the hierarchy measurement of NO$\nu$A.

   hep-phPoS(2018)·0 citations
6. 06*

   Implications of hidden gauged $U(1)$ model for $B$ anomalies

   Kaori Fuyuto🇺🇸 · Hao-Lin Li🇺🇸 · Jiang-Hao Yu🇺🇸

   We propose a hidden gauged $U(1{)}_H$ $Z^{\prime }$ model to explain deviations from the Standard Model (SM) values in lepton flavor universality known as $R_K$ and $R_D$ anomalies. The $Z^{\prime }$ only interacts with the SM fermions via their mixing with vector-like doublet fermions after the $U(1{)}_H$ symmetry breaking, which leads to $b\to s\mu \mu$ transition through the $Z^{\prime }$ at tree level. Moreover, introducing an additional mediator, inert-Higgs doublet, yields $b\to c\tau \nu$ process via charged scalar contribution at tree level. Using flavio package, we scrutinize adequate sizes of the relevant Wilson coefficients to these two processes by taking various flavor observables into account. It is found that significant mixing between the vector-like and the second generation leptons is needed for the $R_K$ anomaly. A possible explanation of the $R_D$ anomaly can also be simultaneously addressed in a motivated situation, where a single scalar operator plays a dominant role, by the successful model parameters for the $R_K$ anomaly.

   hep-phPRD(2018)·44 citations
7. 07*

   Beyond Standard Neutrino Theory

   Toshihiko Ota🇪🇨

   In this talk, we will discuss phenomenology of new physics associated with neutrinos, in particular, non-standard neutrino interactions, non-unitarity of the lepton mixing matrix, and secret neutrino interactions mediated by a light field.

   hep-phPoS(2018)·1 citation
8. 08*

   Towards a fully massive five-flavour scheme

   Frank Krauss🇬🇧 · Davide Napoletano🇬🇧

   In this work we explore first necessary steps to contruct a fully massive version of a variable flavour number scheme. In particular we focus, as an example, on an extension of the five-flavour scheme, where instead of neglecting explicit initial state quark mass effects, we retain all massive dependence, while keeping the resummation properties of the massless five-flavour scheme. We name this scheme five-flavour-massive (5FMS) scheme. Apart from consistently modified parton distribution functions, we provide all the ingredients that are needed to implement this scheme at MC@NLO accuracy, in a Monte Carlo event generator. As proof of concept we implement this scheme in SHERPA, and perfom a comparison of the new scheme with traditional ones for the simple process of scalar particle production in bottom quark fusion.

   hep-phPRD(2018)·47 citations
9. 09*

   Open charm production and low x gluons

   E.G. de Oliveira🇧🇷 · A.D. Martin🇬🇧 · M.G. Ryskin🇬🇧

   We compare the rapidity, $y$, and the beam energy, $\sqrt{s}$, behaviours of the cross section of the data for $D$ meson production in the forward direction that were measured by the LHCb collaboration. We describe the observed cross sections using NLO perturbative QCD, and choose the optimal factorization scale for the LO contribution which provides the resummation of the large double logarithms. We emphasize the inconsistency observed in the $y$ and $\sqrt{s}$ behaviours of the $D$ meson cross sections. The $y$ behaviour indicates a very {\it flat} $x$ dependence of the gluon PDF in the unexplored low $x$ region around $x\sim 10^{-5}$. However, to describe the $\sqrt{s}$ dependence of the data we need a steeper gluon PDF with decreasing $x$. Moreover, an even steeper behaviour is needed to provide an extrapolation which matches on to the well known gluons found in the global PDF analyses for $x\sim 10^{-3}$. The possible role of non-perturbative effects is briefly discussed.

   hep-phPRD(2018)·9 citations
10. 10*

    B-decay anomalies in Pati-Salam SU(4)

    Riccardo Barbieri🇮🇹 · Andrea Tesi🇮🇹

    Attempts to incorporate in a coherent picture the $B$-decay anomalies presumably observed in $b\to c$ and $b\to s$ semi-leptonic decays have to face the absence of signals in other related experiments, both at low and at high energies. By extending and making more precise the content of Ref. [1], we describe one such attempt based on the Pati-Salam SU(4) group, that unifies colour and the $B$-$L$ charge, in the context of a new strongly interacting sector, equally responsible for producing a pseudo-Goldstone Higgs boson.

    hep-phEPJC(2018)·147 citations
11. 11*

    Gauge contribution to the $1/N_F$ expansion of the Yukawa coupling beta function

    Kamila Kowalska🇵🇱 · Enrico Maria Sessolo🇵🇱

    We provide a closed analytical form for the gauge contribution to the beta function of a generic Yukawa coupling in the limit of large $N_F$, where $N_F$ is the number of heavy vector-like fermions charged under an abelian or non-abelian gauge group. The resummed expression is finite and for the abelian case presents a pole at the same location as for the corresponding gauge beta function. When applied to new physics scenarios characterized by large Yukawa couplings, the contribution calculated here can cure their pathological UV behavior and make the couplings asymptotically free.

    hep-phJHEP(2018)·31 citations
12. 12*

    Flavour physics without flavour symmetries

    Wilfried Buchmuller🇩🇪 · Ketan M. Patel🇮🇳

    We quantitatively analyze a quark-lepton flavour model derived from a six-dimensional supersymmetric theory with $SO(10)\times U(1)$ gauge symmetry, compactified on an orbifold with magnetic flux. Two bulk $16$-plets charged under the $U(1)$ provide the three quark-lepton generations whereas two uncharged $10$-plets yield two Higgs doublets. At the orbifold fixed points mass matrices are generated with rank one or two. Moreover, the zero modes mix with heavy vectorlike split multiplets. The model possesses no flavour symmetries. Nevertheless, there exist a number of relations between Yukawa couplings, remnants of the underlying GUT symmetry and the wave function profiles of the zero modes, which lead to a prediction of the light neutrino mass scale, $m_{{\nu }_1}\sim 10^{-3}$ eV and heavy Majorana neutrino masses in the range from $10^{12}$ GeV to $10^{14}$ GeV. The model successfully includes thermal leptogenesis.

    hep-phhep-thPRD(2018)·33 citations
13. 13*

    Electromagnetic field effects on ${\rm Y}$-meson dissociation in PbPb collisions at LHC energies

    J. Hoelck🇩🇪 · G. Wolschin🇩🇪

    We investigate the effect of the electromagnetic field generated in relativistic heavy-ion collisions on the dissociation of ${\rm Y}$ mesons. The electromagnetic field is calculated using a simple model which characterizes the emerging quark-gluon plasma (QGP) by its conductivity only. A numerical estimate of the field strength experienced by ${\rm Y}$ mesons embedded in the expanding QGP and its consequences on the ${\rm Y}$ dissociation is made. The electromagnetic field effects prove to be negligible compared to the established strong-interaction suppression mechanisms.

    hep-phnucl-thEPJA(2017)·18 citations
14. 14*

    GUT Precursors and Entwined SUSY: The Phenomenology of Stable Non-Supersymmetric Strings

    Steven Abel🇬🇧 · Keith R. Dienes🇺🇸 · Eirini Mavroudi🇬🇧

    Recent work has established a method of constructing non-supersymmetric string models that are stable, with near-vanishing one-loop dilaton tadpoles and cosmological constants. This opens up the tantalizing possibility of realizing stable string models whose low-energy limits directly resemble the Standard Model rather than one of its supersymmetric extensions. In this paper we consider the general structure of such strings and find that they share two important phenomenological properties. The first is a so-called "GUT-precursor" structure in which new GUT-like states appear with masses that can be many orders of magnitude lighter than the scale of gauge coupling unification. These states allow a parametrically large compactification volume, even in weakly coupled heterotic strings, and in certain regions of parameter space can give rise to dramatic collider signatures which serve as "smoking guns" for this overall string framework. The second is a residual "entwined-SUSY" (or e-SUSY) structure for the matter multiplets in which different multiplet components carry different horizontal $U(1)$ charges. As a concrete example and existence proof of these features, we present a heterotic string model that contains the fundamental building blocks of the Standard Model such as the Standard-Model gauge group, complete chiral generations, and Higgs fields --- all without supersymmetry. Even though massless gravitinos and gauginos are absent from the spectrum, we confirm that this model has an exponentially suppressed one-loop dilaton tadpole and displays both the GUT-precursor and e-SUSY structures. We also discuss some general phenomenological properties of e-SUSY, such as cancellations in radiative corrections to scalar masses, the possible existence of a corresponding approximate moduli space, and the prevention of rapid proton decay.

    hep-phhep-thPRD(2018)·49 citations
15. 15*

    Evidence of ghost suppression in gluon mass dynamics

    A. C. Aguilar🇧🇷 · D. Binosi🇮🇹 · C. T. Figueiredo🇧🇷 · J. Papavassiliou🇪🇸

    In this work we study the impact that the ghost sector of pure Yang-Mills theories may have on the generation of a dynamical gauge boson mass, which hinges on the appearance of massless poles in the fundamental vertices of the theory, and the subsequent realization of the well-known Schwinger mechanism. The process responsible for the formation of such structures is itself dynamical in nature, and is governed by a set of Bethe-Salpeter type of integral equations. While in previous studies the presence of massless poles was assumed to be exclusively associated with the background-gauge three-gluon vertex, in the present analysis we allow them to appear also in the corresponding ghost-gluon vertex. The full analysis of the resulting Bethe-Salpeter system reveals that the contribution of the poles associated with the ghost-gluon vertex are particularly suppressed, their sole discernible effect being a slight modification in the running of the gluon mass, for momenta larger than a few GeV. In addition, we examine the behavior of the (background-gauge) ghost-gluon vertex in the limit of vanishing ghost momentum, and derive the corresponding version of Taylor's theorem. These considerations, together with a suitable Ansatz, permit us the full reconstruction of the pole sector of the two vertices involved.

    hep-phhep-lathep-thEPJC(2018)·56 citations
16. 16*

    Comments on glueballs as gravitons

    Matteo Rinaldi🇪🇸 · Vicente Vento🇪🇸

    The graviton solutions for the glueball spectrum of ref. \cite{Rinaldi:2017wdn} interpreted in a different manner lead to very interesting results which we describe in this comment.

    hep-ph0 citations
17. 17*

    NNLO QCD corrections to associated $WH$ production and $H\to b\bar{b}$ decay

    Fabrizio Caola🇬🇧 · Gionata Luisoni🇩🇪 · Kirill Melnikov🇩🇪 · Raoul Röntsch🇩🇪

    We present a computation of the next-to-next-to-leading order (NNLO) QCD corrections to the production of a Higgs boson in association with a W boson at the LHC and the subsequent decay of the Higgs boson into a b-bbar pair, treating the b-quarks as massless. We consider various kinematic distributions and find significant corrections to observables that resolve the Higgs decay products. We also find that a cut on the transverse momentum of the W boson, important for experimental analyses, may have a significant impact on kinematic distributions and radiative corrections. We show that some of these effects can be adequately described by simulating QCD radiation in Higgs boson decays to b-quarks using parton showers. We also describe contributions to Higgs decay to a b-bbar pair that first appear at NNLO and that were not considered in previous fully-differential computations. The calculation of NNLO QCD corrections to production and decay sub-processes is carried out within the nested soft-collinear subtraction scheme presented by some of us earlier this year. We demonstrate that this subtraction scheme performs very well, allowing a computation of the coefficient of the second order QCD corrections at the level of a few per mill.

    hep-phPRD(2018)·77 citations
18. 18*

    Towards a complete reconstruction of supernova neutrino spectra in future large liquid-scintillator detectors

    Hui-Ling Li🇨🇳 · Yu-Feng Li🇨🇳 · Meng Wang🇨🇳 · Liang-Jian Wen🇨🇳 · Shun Zhou🇨🇳

    In this paper, we show how to carry out a relatively more realistic and complete reconstruction of supernova neutrino spectra in the future large liquid-scintillator detectors, by implementing the method of singular value decomposition with a proper regularization. For a core-collapse supernova at a distance of $10\mathrm{kpc}$ in the Milky Way, its ${\overline{\nu }}_e^{}$ spectrum can be precisely determined from the inverse beta-decay process ${\overline{\nu }}_e^{}+p\to e^{+}+n$, for which a $20\mathrm{kiloton}$ liquid-scintillator detector with the resolution similar to the Jiangmen Underground Neutrino Observatory (JUNO) may register more than 5000 events. We have to rely predominantly on the elastic neutrino-electron scattering $\nu +e^{-}\to \nu +e^{-}$ and the elastic neutrino-proton scattering $\nu +p\to \nu +p$ for the spectra of ${\nu }_e^{}$ and ${\nu }_x^{}$, where $\nu$ denotes collectively neutrinos and antineutrinos of all three flavors and ${\nu }_x^{}$ for ${\nu }_{\mu }^{}$ and ${\nu }_{\tau }^{}$ as well as their antiparticles. To demonstrate the validity of our approach, we also attempt to reconstruct the neutrino spectra by using the time-integrated neutrino data from the latest numerical simulations of delayed neutrino-driven supernova explosions.

    hep-phastro-ph.HEPRD(2018)·32 citations
19. 19*

    Fast neutrino flavor conversion: roles of dense matter and spectrum crossing

    Sajad Abbar🇺🇸 · Huaiyu Duan (UNM)🇺🇸

    The flavor conversion of a neutrino usually occurs at densities $\lesssim G_F^{-1}\omega$, whether in the ordinary matter or the neutrino medium, and on time/distance scales of order ${\omega }^{-1}$, where $G_F$ is the Fermi weak coupling constant and $\omega$ is the vacuum oscillation frequency of the neutrino. In 2005 Sawyer and more recently both he and other groups have shown that neutrino flavor conversions can occur on scales much shorter than ${\omega }^{-1}$ in a very dense, anisotropic neutrino gas such as that in a core-collapse supernova or a binary neutron star merger. It has also been suggested that the fast neutrino flavor conversion require a crossing in the electron lepton number (ELN) angular distribution or spectrum. We study a few simple analytical models with which we elucidate the roles of the dense matter and the ELN spectrum crossing in neutrino fast flavor conversions. We show that a large matter density can induce fast neutrino flavor conversions in certain astrophysical scenarios such as at the early epoch of a core-collapse supernova.

    hep-phastro-ph.HEnucl-thPRD(2018)·93 citations
20. 20*

    Measurements of $\gamma \gamma \to \text{mbox}Higgs$ and $\gamma \gamma \to W^{+}{W}^{-}$ in $e^{+}{e}^{-}$ collisions at the Future Circular Collider

    David d'Enterria🇨🇭 · Patricia Rebello Teles🇧🇷 · Daniel E. Martins🇧🇷

    The measurements of the two-photon production of the Higgs boson and of $W^{\pm }$ boson pairs in $e^{+}{e}^{-}$ collisions at the Future Circular Collider (FCC-ee) are investigated. The processes $e^{+}{e}^{-}\stackrel{\gamma \gamma }{\to }{e}^{+}\mathrm{H}{e}^{-},e^{+}{\mathrm{W}}^{+}{\mathrm{W}}^{-}{e}^{-}$ are computed using the effective photon approximation for electron-positron beams, and studied in their $\mathrm{H}\to b\bar{b}$ and ${\mathrm{W}}^{+}{\mathrm{W}}^{-}\to 4j$ decay final-states including parton showering and hadronization, jet reconstruction, $e^{\pm }$ forward tagging, and realistic experimental cuts. After selection criteria, up to 75 Higgs bosons and 6600 ${\mathrm{W}}^{\pm }$ pairs will be reconstructed on top of controllable continuum backgrounds at $\sqrt{s}=$240 and 350 GeV for the total expected integrated luminosities, by tagging the scattered $e^{\pm }$ with near-beam detectors. A 5$\sigma$ observation of $\gamma \gamma \to$H is thereby warranted, as well as high-statistics studies of triple $\gamma \mathrm{WW}$ and quartic $\gamma \gamma \mathrm{WW}$ electroweak couplings, improving by at least factors of 2 and 10 the current limits on dimension-6 anomalous quartic gauge couplings.

    hep-phhep-ex5 citations
21. 21*

    Gluon Shadowing in Heavy-Flavor Production at the LHC

    Aleksander Kusina🇵🇱 · Jean-Philippe Lansberg🇫🇷 · Ingo Schienbein🇫🇷 · Hua-Sheng Shao🇫🇷

    We study the relevance of experimental data on heavy-flavor [$D^0$, $J/\psi$, $B\to J/\psi$ and ${\rm Y}(1S)$ mesons] production in proton-lead collisions at the LHC to improve our knowledge of the gluon-momentum distribution inside heavy nuclei. We observe that the nuclear effects encoded in both most recent global fits of nuclear parton densities at next-to-leading order (nCTEQ15 and EPPS16) provide a good overall description of the LHC data. We interpret this as a hint that these are the dominant ones. In turn, we perform a Bayesian-reweighting analysis for each particle data sample which shows that each of the existing heavy-quark(onium) data set clearly points --with a minimal statistical significance of 7 $\sigma$-- to a shadowed gluon distribution at small $x$ in the lead. Moreover, our analysis corroborates the existence of gluon antishadowing. Overall, the inclusion of such heavy-flavor data in a global fit would significantly reduce the uncertainty on the gluon density down to $x\simeq 7\times 10^{-6}$ --where no other data exist-- while keeping an agreement with the other data of the global fits. Our study accounts for the factorization-scale uncertainties which dominate for the charm(onium) sector.

    hep-phhep-exnucl-exnucl-thPRL(2018)·171 citations
22. 22*

    Iterating QCD scattering amplitudes in the high-energy limit

    Vittorio Del Duca🇨🇭

    We analyse the high-energy limit of the gluon-gluon scattering amplitude in QCD, and display an intriguing relation between the finite parts of the one-loop gluon impact factor and the finite parts of the two-loop Regge trajectory.

    hep-phhep-thJHEP(2018)·14 citations
23. 23*

    The effects of explicit chiral symmetry breaking multiquark interactions on the spin 0 and 1 meson nonets: the ruling of the vector mesons

    Jorge Morais🇵🇹 · Brigitte Hiller🇵🇹 · Alexander A. Osipov🇷🇺

    We have recently extended the scalar-pseudoscalar sector of a generalized NJL Lagrangian that includes all NLO non derivative interactions in Nc counting (including explicit symmetry breaking ones) in order to incorporate the spin 1 mesons in the low-lying ground state of QCD [1]. Upon bosonization, the well known mixing of the scalar-vector and of the pseudoscalar- axial-vector fields occurs in the quadratic part of the Lagrangian. We show that a linearized diagonalization of these terms can be effected in a completely general way without compromising the underlying symmetries of the Lagrangian [2]. The resulting spin 1 mass spectra evidence a relation involving only the vector and axial-vector meson masses and the constituent quark masses. We discuss the dominant role of this relation in the fits and we show that the model may be fitted to accommodate to a very good accuracy the 4 low-lying meson spectra.

    hep-phPoS(2018)·0 citations
24. 24*

    Illuminating the photon content of the proton within a global PDF analysis

    Valerio Bertone🇳🇱 · Stefano Carrazza🇨🇭 · Nathan P. Hartland🇳🇱 · Juan Rojo🇳🇱

    Precision phenomenology at the LHC requires accounting for both higher-order QCD and electroweak corrections as well as for photon-initiated subprocesses. Building upon the recent NNPDF3.1 fit, in this work the photon content of the proton is determined within a global analysis supplemented by the LUXqed constraint relating the photon PDF to lepton-proton scattering structure functions: NNPDF3.1luxQED. The uncertainties on the resulting photon PDF are at the level of a few percent, with photons carrying up to 0.5% of the proton's momentum. We study the phenomenological implications of NNPDF3.1luxQED at the LHC for Drell-Yan, vector boson pair, top quark pair, and Higgs plus vector boson production. We find that photon-initiated contributions can be significant for many processes, leading to corrections of up to 20%. Our results represent a state-of-the-art determination of the partonic structure of the proton including its photon component.

    hep-phhep-exnucl-thSciPost Phys.(2018)·295 citations
25. 25*

    Post-inflationary Scalar Tensor Cosmology and Inflationary Parameters

    Anshuman Maharana🇮🇳 · Ivonne Zavala🇬🇧

    Scalar fields provide attractive modifications of pre-BBN cosmology, which have interesting implications for dark matter abundances. We analyse the effect of these modifications on the number of e-foldings between horizon exit of CMB modes and the end of inflation $(N_k)$, and examine the consequences for inflationary predictions of various models. We find significant effects in the predictions in the $(n_s,r)$ plane. For a large part of the parameter space, the shift in $N_k$ is positive; this ameliorates the tension of $m^2{\phi }^2$ and natural inflation with data.

    hep-phastro-ph.COhep-thPRD(2018)·18 citations
26. 26*

    Elliptic polylogarithms and iterated integrals on elliptic curves II: an application to the sunrise integral

    Johannes Broedel🇩🇪 · Claude Duhr🇨🇭 · Falko Dulat🇺🇸 · Lorenzo Tancredi🇨🇭

    We introduce a class of iterated integrals that generalize multiple polylogarithms to elliptic curves. These elliptic multiple polylogarithms are closely related to similar functions defined in pure math- ematics and string theory. We then focus on the equal-mass and non-equal-mass sunrise integrals, and we develop a formalism that enables us to compute these Feynman integrals in terms of our iterated integrals on elliptic curves. The key idea is to use integration-by-parts identities to identify a set of integral kernels, whose precise form is determined by the branch points of the integral in question. These kernels allow us to express all iterated integrals on an elliptic curve in terms of them. The flexibility of our approach leads us to expect that it will be applicable to a large variety of integrals in high-energy physics.

    hep-phhep-thPRD(2018)·184 citations
27. 27*

    Energy flow polynomials: A complete linear basis for jet substructure

    Patrick T. Komiske🇺🇸 · Eric M. Metodiev🇺🇸 · Jesse Thaler🇺🇸

    We introduce the energy flow polynomials: a complete set of jet substructure observables which form a discrete linear basis for all infrared- and collinear-safe observables. Energy flow polynomials are multiparticle energy correlators with specific angular structures that are a direct consequence of infrared and collinear safety. We establish a powerful graph-theoretic representation of the energy flow polynomials which allows us to design efficient algorithms for their computation. Many common jet observables are exact linear combinations of energy flow polynomials, and we demonstrate the linear spanning nature of the energy flow basis by performing regression for several common jet observables. Using linear classification with energy flow polynomials, we achieve excellent performance on three representative jet tagging problems: quark/gluon discrimination, boosted W tagging, and boosted top tagging. The energy flow basis provides a systematic framework for complete investigations of jet substructure using linear methods.

    hep-phhep-exJHEP(2018)·194 citations
28. 28*

    Inelastic Boosted Dark Matter at Direct Detection Experiments

    Gian F. Giudice🇨🇭 · Doojin Kim🇨🇭 · Jong-Chul Park🇰🇷 · Seodong Shin🇺🇸

    We explore a novel class of multi-particle dark sectors, called Inelastic Boosted Dark Matter (iBDM). These models are constructed by combining properties of particles that scatter off matter by making transitions to heavier states (Inelastic Dark Matter) with properties of particles that are produced with a large Lorentz boost in annihilation processes in the galactic halo (Boosted Dark Matter). This combination leads to new signals that can be observed at ordinary direct detection experiments, but require unconventional searches for energetic recoil electrons in coincidence with displaced multi-track events. Related experimental strategies can also be used to probe MeV-range boosted dark matter via their interactions with electrons inside the target material.

    hep-phhep-exPLB(2018)·101 citations
29. 29*

    New Physics Opportunities for Long-Lived Particles at Electron-Proton Colliders

    David Curtin🇺🇸 · Kaustubh Deshpande🇺🇸 · Oliver Fischer🇩🇪 · Jose Zurita🇩🇪

    Future electron-proton collider proposals like the LHeC or the FCC-eh can supply 1/ab of collisions with a center-of-mass energy in the TeV range, while maintaining a clean experimental environment more commonly associated with lepton colliders. We point out that this makes electron-proton colliders ideally suited to probe BSM signatures with final states that look like "hadronic noise" in the high-energy, pile-up-rich environment of hadron colliders. We focus on the generic vector boson fusion production mechanism, which is available for all BSM particles with electroweak charges at mass scales far above the reach of most lepton colliders. This is in contrast to previous BSM studies at these machines, which focused on BSM processes with large production rates from the asymmetric initial state. We propose to exploit the unique experimental environment in the search for long-lived particle signals arising from Higgsinos or exotic Higgs decays. At electron-proton colliders, the soft decay products of long-lived Higgsinos can be explicitly reconstructed ("displaced single pion"), and very short lifetimes can be probed. We find that electron-proton colliders can explore significant regions of BSM parameter space inaccessible to other collider searches, with important implications for the design of such machines.

    hep-phJHEP(2018)·59 citations
30. 30*

    PeV scale Supersymmetry breaking and the IceCube neutrino flux

    Mansi Dhuria🇮🇳 · Vikram Rentala🇮🇳

    The observation of very high energy neutrino events at IceCube has grasped a lot of attention in the fields of both astrophysics and particle physics. It has been speculated that these high energy neutrinos might originate either from purely conventional astrophysical sources or from the late decay of a super heavy (PeV scale) dark matter (DM) particle. In order for decaying DM to be a dominant source of the IceCube high-energy neutrinos, it would require an unusually suppressed value of the coupling of DM to neutrinos. We attempt to explain this small coupling in the context of an $R$-parity conserving minimal supergravity model which has right-handed neutrino superfields. With the main assumptions of super-partner masses at the PeV scale and also a reheating temperature not much larger than the PeV scale, we find in our model several natural order-of-magnitude "miracles", (i) the gravitino is produced via freeze-in as a DM candidate with the correct relic density (ii) the right-handed (RH) sneutrino makes up only a tiny fraction ($10^{-6})$, of the present day energy density of the universe, yet its decay lifetime to the gravitino and neutrinos is such that it naturally predicts the right order-of-magnitude for the IceCube neutrino flux. The long lifetime of the RH sneutrino is explained by the existence of a global $R$-symmetry which is only broken due to supersymmetry breaking effects. Our model also predicts a flux of 100 TeV gamma rays from the decaying RH sneutrino which are within the current observational constraints.

    hep-phastro-ph.HEhep-exJHEP(2018)·18 citations
31. 31*

    Evidence for M-theory based on fractal nearly tri-bimaximal neutrino mixing

    Hui-Bin Qiu🇨🇳

    Developing a theory that can describe everything in the universe is of great interest, and is closely relevant to M-theory, neutrino oscillation and charge-parity (CP) violation. Although M-theory is claimed as a grand unified theory, it has not been tested by any direct experiment. Here we show that existing neutrino oscillation experimental data supports one kind of high dimensional unified theory, such as M-theory. We propose a generalization of the tri-bimaximal neutrino mixing ansatz, and we find that the latest neutrino oscillation experimental data constraints dimension in a range between 10.46 and 12.93 containing 11, which is an important prediction of M-theory. This ansatz naturally incorporates the fractal feature of the universe and leptonic CP violation into the resultant scenario of \textit{fractal} nearly tri-bimaximal flavor mixing. We also analyze the consequences of this new ansatze on the latest experimental data of neutrino oscillations, and this theory matches the experimental data. Furthermore, an approach to construct lepton mass matrices in fractal universe under permutation symmetry is discussed. The proposed theory opens an unexpected window on the physics beyond the Standard Model.

    hep-ph2 citations
32. 32*

    Gravitational probes of dark matter physics

    Matthew R. Buckley🇺🇸 · Annika H.G. Peter🇺🇸

    The nature of dark matter is one of the most pressing questions in particle physics. Yet all our present knowledge of the dark sector to date comes from its gravitational interactions with astrophysical systems. Moreover, astronomical results still have immense potential to constrain the particle properties of dark matter. We introduce a simple 2D parameter space which classifies models in terms of a particle physics interaction strength and a characteristic astrophysical scale on which new physics appears, in order to facilitate communication between the fields of particle physics and astronomy. We survey the known astrophysical anomalies that are suggestive of non-trivial dark matter particle physics, and present a theoretical and observational program for future astrophysical measurements that will shed light on the nature of dark matter.

    ↳ astro-ph.COhep-phPhys.Rept.(2018)·203 citations
33. 33*

    Imprints of Spinning Particles on Primordial Cosmological Perturbations

    Gabriele Franciolini (1)🇨🇭 · Alex Kehagias (2)🇬🇷 · Antonio Riotto (1) ((1) Department of Theoretical Physics and Center for Astroparticle Physics (CAP), Geneva, Switzerland, (2) Physics Division, National Technical University of Athens, Greece)🇨🇭

    If there exist higher-spin particles during inflation which are light compared to the Hubble rate, they may leave distinct statistical anisotropic imprints on the correlators involving scalar and graviton fluctuations. We characterise such signatures using the dS/CFT${}_3$ correspondence and the operator product expansion techniques. In particular, we obtain generic results for the case of partially massless higher-spin states.

    ↳ hep-thastro-ph.COgr-qchep-phJCAP(2018)·63 citations
34. 34*

    Gravitational radiation from a bulk flow model

    Thomas Konstandin🇩🇪

    We perform simulations in a simple model that aims to mimic the hydrodynamic evolution of a relativistic fluid during a cosmological first-order phase transitions. The observable we are concerned with is hereby the spectrum of gravitational radiation produced by colliding fluid shells. We present simple parameterizations of our results as functions of the wall velocity, the duration of the phase transition and the latent heat. We also improve on previous results in the envelope approximation and compare with hydrodynamic simulations.

    ↳ astro-ph.COhep-phJCAP(2018)·154 citations
35. 35*

    MultivariateResidues - a Mathematica package for computing multivariate residues

    Kasper J. Larsen🇬🇧 · Robbert Rietkerk🇩🇪

    We present the Mathematica package MultivariateResidues, which allows for the efficient evaluation of multivariate residues based on methods from computational algebraic geometry. Multivariate residues appear in several contexts of scattering amplitude computations. Examples include applications to the extraction of master integral coefficients from maximal unitarity cuts, the construction of canonical bases of loop integrals and the construction of tree amplitudes from scattering equations.

    ↳ hep-thhep-phmath.AGmath.CVPoS(2017)·4 citations
36. 36*

    Elliptic polylogarithms and iterated integrals on elliptic curves I: general formalism

    Johannes Broedel🇩🇪 · Claude Duhr🇨🇭 · Falko Dulat🇺🇸 · Lorenzo Tancredi🇨🇭

    We introduce a class of iterated integrals, defined through a set of linearly independent integration kernels on elliptic curves. As a direct generalisation of multiple polylogarithms, we construct our set of integration kernels ensuring that they have at most simple poles, implying that the iterated integrals have at most logarithmic singularities. We study the properties of our iterated integrals and their relationship to the multiple elliptic polylogarithms from the mathematics literature. On the one hand, we find that our iterated integrals span essentially the same space of functions as the multiple elliptic polylogarithms. On the other, our formulation allows for a more direct use to solve a large variety of problems in high-energy physics. We demonstrate the use of our functions in the evaluation of the Laurent expansion of some hypergeometric functions for values of the indices close to half integers.

    ↳ hep-thhep-phJHEP(2018)·257 citations
37. 37*

    Status of neutrino properties and future prospects - Cosmological and astrophysical constraints

    Massimiliano Lattanzi🇮🇹 · Martina Gerbino🇸🇪

    Cosmological observations are a powerful probe of neutrino properties, and in particular of their mass. In this review, we first discuss the role of neutrinos in shaping the cosmological evolution at both the background and perturbation level, and describe their effects on cosmological observables such as the cosmic microwave background and the distribution of matter at large scale. We then present the state of the art concerning the constraints on neutrino masses from those observables, and also review the prospects for future experiments. We also briefly discuss the prospects for determining the neutrino hierarchy from cosmology, the complementarity with laboratory experiments, and the constraints on neutrino properties beyond their mass.

    ↳ astro-ph.COhep-phFront.in Phys.(2018)·206 citations
38. 38*

    Constraints on scattering of keV--TeV dark matter with protons in the early Universe

    Vera Gluscevic🇺🇸 · Kimberly K. Boddy🇺🇸

    We present the first cosmological constraint on dark matter scattering with protons in the early Universe for the entire range of dark matter masses between 1 keV and 1 TeV. This constraint is derived from the Planck measurements of the cosmic microwave background (CMB) temperature and polarization anisotropy, and the CMB lensing anisotropy. It improves upon previous CMB constraints by many orders of magnitude, where limits are available, and closes the gap in coverage for low-mass dark matter candidates. We focus on two canonical interaction scenarios: spin-independent and spin-dependent scattering with no velocity dependence. Our results exclude (with 95% confidence) spin-independent interactions with cross sections greater than $5.3\times 10^{-27}$ cm${}^2$ for 1 keV, $3.0\times 10^{-26}$ cm${}^2$ for 1 MeV, $1.7\times 10^{-25}$ cm${}^2$ for 1 GeV, and $1.6\times 10^{-23}$ cm${}^2$ for 1 TeV dark matter mass. Finally, we discuss the implications of this study for dark matter physics and future observations.

    ↳ astro-ph.COhep-phPRL(2018)·206 citations
39. 39*

    Muon-neutrino-induced charged current cross section without pions: Theoretical analysis

    U. Mosel🇩🇪 · K. Gallmeister🇩🇪

    We calculate the charged current cross sections obtained at the T2K near detector for ${\nu }_{\mu }$-induced events without pions in the final state. The method used is quantum-kinetic transport theory. Results are shown first, as a benchmark, for electron inclusive cross sections on ${}^{12}$C and ${}^{16}$O to be followed with a detailed comparison with the data measured by the T2K collaboration on C${}_8$H${}_8$ and H${}_2$O targets. The contribution of 2p2h processes is found to be relevant mostly for backwards angles; their theoretical uncertainties are within the experimental uncertainties. Particular emphasis is then put on a discussion of events in which pions are first created, but then reabsorbed. Their contribution is found to be essential at forward angles.

    ↳ hep-exhep-phnucl-exnucl-thPRC(2018)·21 citations
40. 40*

    Complex Langevin Simulation of a Random Matrix Model at Nonzero Chemical Potential

    J. Bloch🇩🇪 · J. Glesaaen🇬🇧 · J. J. M. Verbaarschot🇺🇸 · S. Zafeiropoulos🇩🇪

    In this paper we test the complex Langevin algorithm for numerical simulations of a random matrix model of QCD with a first order phase transition to a phase of finite baryon density. We observe that a naive implementation of the algorithm leads to phase quenched results, which were also derived analytically in this article. We test several fixes for the convergence issues of the algorithm, in particular the method of gauge cooling, the shifted representation, the deformation technique and reweighted complex Langevin, but only the latter method reproduces the correct analytical results in the region where the quark mass is inside the domain of the eigenvalues. In order to shed more light on the issues of the methods we also apply them to a similar random matrix model with a milder sign problem and no phase transition, and in that case gauge cooling cooling solves the convergence problems as was shown before in the literature.

    ↳ hep-lathep-phnucl-thJHEP(2018)·46 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.