Tue·Mar 22, 2016Tuesday·March 22, 2016

1. 01*

   The Lepton Flavour Violating Higgs Decays at the HL-LHC and the ILC

   Shankha Banerjee🇫🇷 · Biplob Bhattacherjee🇮🇳 · Manimala Mitra🇮🇳 · Michael Spannowsky🇬🇧

   Run-I results from the CMS collaboration show an excess of events in the decay $h\to \mu {\tau }_e$ with a local significances of 2.4$\sigma$. This could be the first hint of flavour violation in the Higgs sector. We summarise the bounds on the flavour violating Yukawa couplings from direct searches, low energy measurements and projected future experiments. We discuss the sensitivity of upcoming HL-LHC runs and future lepton colliders in measuring lepton-flavour violating couplings using an effective field theory framework. For the HL-LHC we find limits on BR($h\to \mu \tau$) and BR$(h\to e\tau )\lesssim \mathcal{O}(0.5)\%$ and on BR($h\to e\mu )\lesssim \mathcal{O}(0.02)\%$. For an ILC with center-of-mass energy of 1 TeV we expect BR($h\to e\tau$) and BR($h\to \mu \tau$) to be measurable down to $\mathcal{O}(0.2)\%$.

   hep-phhep-exJHEP(2016)·52 citations
2. 02*

   Tutorial to SARAH

   Florian Staub🇨🇭

   I give in this brief tutorial a short practical introduction to the Mathematica package SARAH. First, it is shown how an existing model file can be changed to implement a new model in SARAH. In the second part, masses, vertices and renormalisation group equations are calculated with SARAH. Finally, the main commands to generate model files and output for other tools are summarised.

   hep-phPoS(2016)·4 citations
3. 03*

   Diphoton Resonance from a Warped Extra Dimension

   Martin Bauer (Univ. Heidelberg)🇩🇪 · Clara Hoerner (Univ. Mainz)🇩🇪 · Matthias Neubert (MITP Mainz)🇩🇪

   We argue that extensions of the Standard Model (SM) with a warped extra dimension, which successfully address the hierarchy and flavor problems of elementary particle physics, can provide an elegant explanation of the 750 GeV diphoton excess recently reported by ATLAS and CMS. A gauge-singlet bulk scalar with $\mathcal{O}(1)$ couplings to fermions is identified as the new resonance $S$, and the vector-like Kaluza-Klein excitations of the SM quarks and leptons mediate its loop-induced couplings to photons and gluons. The electroweak gauge symmetry almost unambiguously dictates the bulk matter content and hence the hierarchies of the $S\to \gamma \gamma$, $WW$, $ZZ$, $Z\gamma$, $t\bar{t}$ and dijet decay rates. We find that the $S\to Z\gamma$ decay mode is strongly suppressed, such that $\text{mbox}Br(S\to Z\gamma )/\text{mbox}Br(S\to \gamma \gamma )<0.1$. The hierarchy problem for the new scalar boson is solved in analogy with the Higgs boson by localizing it near the infrared brane. The infinite sums over the Kaluza-Klein towers of fermion states are finite and can be calculated in closed form with a remarkably simple result. Reproducing the observed $pp\to S\to \gamma \gamma$ signal requires Kaluza-Klein masses in the multi-TeV range, consistent with bounds from flavor physics and electroweak precision observables. Useful side products of our analysis, which can be adapted to almost any model for the diphoton resonance, are the calculation of the gluon-fusion production cross section $\sigma (pp\to S)$ at NNLO in QCD, an exact expression for the inclusive $S\to gg$ decay rate at N${}^3$LO, a study of the $S\to t\bar{t}h$ three-body decay and a phenomenological analysis of portal couplings connecting $S$ with the Higgs field.

   hep-phJHEP(2016)·39 citations
4. 04*

   Effective Field Theory of Dark Matter: a Global Analysis

   Sebastian Liem🇳🇱 · Gianfranco Bertone🇳🇱 · Francesca Calore🇳🇱 · Roberto Ruiz de Austri🇪🇸 · Tim M.P. Tait🇺🇸 · Roberto Trotta🇬🇧 · Christoph Weniger🇳🇱

   We present global fits of an effective field theory description of real, and complex scalar dark matter candidates. We simultaneously take into account all possible dimension 6 operators consisting of dark matter bilinears and gauge invariant combinations of quark and gluon fields. We derive constraints on the free model parameters for both the real (five parameters) and complex (seven) scalar dark matter models obtained by combining Planck data on the cosmic microwave background, direct detection limits from LUX, and indirect detection limits from the Fermi Large Area Telescope. We find that for real scalars indirect dark matter searches disfavour a dark matter particle mass below 100 GeV. For the complex scalar dark matter particle current data have a limited impact due to the presence of operators that lead to p-wave annihilation, and also do not contribute to the spin-independent scattering cross- section. Although current data are not informative enough to strongly constrain the theory parameter space, we demonstrate the power of our formalism to reconstruct the theoretical parameters compatible with an actual dark matter detection, by assuming that the excess of gamma rays observed by the Fermi Large Area Telescope towards the Galactic centre is entirely due to dark matter annihilations. Please note that the excess can very well be due to astrophysical sources such as millisecond pulsars. We find that scalar dark matter interacting via effective field theory operators can in principle explain the Galactic centre excess, but that such interpretation is in strong tension with the non-detection of gamma rays from dwarf galaxies in the real scalar case. In the complex scalar case there is enough freedom to relieve the tension.

   hep-phastro-ph.HEJHEP(2016)·53 citations
5. 05*

   Analysis of the $D_{s3}^{\ast }(2860)$ as a D-wave $c\bar{s}$ meson with QCD sum rules

   Zhi-Gang Wang🇨🇳

   In this article, we assign the $D_{s3}^{\ast }(2860)$ to be a D-wave $c\bar{s}$ meson, and study the mass and decay constant of the $D_{s3}^{\ast }(2860)$ with the QCD sum rules by calculating the contributions of the vacuum condensates up to dimension-6 in the operator product expansion. The predicted mass $M_{D_{s3}^{\ast }}=(2.86\pm 0.10)\mathrm{GeV}$ is in excellent agreement with the experimental value $M_{D_{s3}^{\ast }}=(2860.5\pm 2.6\pm 2.5\pm 6.0)\mathrm{MeV}$ from the LHCb collaboration. The present prediction supports assigning the $D_{s3}^{\ast }(2860)$ to be the D-wave $c\bar{s}$ meson.

   hep-phNPA(2017)·8 citations
6. 06*

   Diffractive dijet photoproduction in ultraperipheral collisions at the LHC in next-to-leading order QCD

   V. Guzey (PNPI, Gatchina)🇷🇺 · M. Klasen (Muenster U.)🇩🇪

   We make predictions for the cross sections of diffractive dijet photoproduction in $pp$, $pA$ and $AA$ ultraperipheral collisions (UPCs) at the LHC during Runs 1 and 2 using next-to-leading perturbative QCD. We find that the resulting cross sections are sufficiently large and, compared to lepton-proton scattering at HERA, have an enhanced sensitivity to small observed momentum fractions in the diffractive exchange, commonly denoted $z_P^{\mathrm{jets}}$, and an unprecedented reach in the invariant mass of the photon-nucleon system $W$. We examine two competing schemes of diffractive QCD factorization breaking, which assume either a global suppression factor or a suppression for resolved photons only and demonstrate that the two scenarios can be distinguished by the nuclear dependence of the distributions in the observed parton momentum fraction in the photon $x_{\gamma }^{\mathrm{jets}}$.

   hep-phhep-exnucl-exJHEP(2016)·55 citations
7. 07*

   Reinterpretation of ATLAS 8 TeV searches for Natural SUSY with a $R$-Sneutrino LSP

   Lukas Mitzka🇩🇪 · Werner Porod🇩🇪

   The data obtained by the LHC collaborations clearly show that supersymmetric models are not realized in nature in a vanilla form and that in particular strongly interacting supersymmetric particles are most likely heavier than expected. An exception are the partners of the third generation quarks, which also play a dominant role in the breaking of the electroweak symmetry. We consider here an extended class of so-called `natural supersymmetric models' where we allow for a sneutrino as the lightest supersymmetric particle as it appears for example in left-right symmetric models and/or models where supersymmetry is explained via an inverse seesaw mechanism. We evaluate how much existing ATLAS data constrain such scenarios and obtain roughly a bound of 300 GeV on the charginos if the sneutrinos are lighter than about 120 GeV. For the stop we find that only masses up to 300 GeV are excluded independent of the mixing angle. For larger values the exclusion depends on the detail of the scenario and if the mass exceeds 800 GeV no bound is obtained.

   hep-ph5 citations
8. 08*

   Higgs naturalness and the scalar boson proliferation instability problem

   James D. Wells🇺🇸

   Sensitivity to the square of the cutoff scale of quantum corrections of the Higgs boson mass self-energy has led many authors to conclude that the Higgs theory suffers from a naturalness or fine-tuning problem. However, speculative new physics ideas to solve this problem have not manifested themselves yet at high-energy colliders, such as the Large Hadron Collider at CERN. For this reason, the role of naturalness as a guide to theory model-building is being severely questioned. Most attacks suggest that one should not resort to arguments involving gravity, which is a much less understood quantum field theory. Another line of attack is against the assumption that there exists a multitude of additional heavy states specifically charged under the Standard Model gauge symmetries. Nevertheless, if we give ground on both of these assaults on naturalness, what remains is a naturalness concern over the prospect of numerous additional spin-zero scalar states in nature. The proliferation of heavy scalars generically destabilizes the Higgs boson mass, raising it to the highest and most remote scalar mass values in nature, thus straining the legitimacy of the Standard Model. The copious use of extra scalars in theory model building, from explaining flavor physics to providing an inflationary potential and more, and the generic expectation of extra scalar bosons in nature argues for the proliferation instability problem being the central concern for naturalness of the Standard Model. Some approaches to solving this problem are presented.

   hep-phSynthese(2017)·34 citations
9. 09*

   Distinguishing CP-odd couplings of the Higgs boson to weak boson pairs

   Siddharth Dwivedi🇮🇳 · Dilip Kumar Ghosh🇮🇳 · Biswarup Mukhopadhyaya🇮🇳 · Ambresh Shivaji🇮🇹

   We consider the observable effects of CP-violating anomalous $ZZh$ interaction arising from gauge invariant dimension-6 operators at the Large Hadron Collider (LHC), with the purpose of distinguishing them from not only the standard model effects but also those of CP-even anomalous interactions of similar nature. The postulation of a gauge invariant origin makes various couplings of this kind interrelated. The updated constraints from the LHC as well as limits from neutron and electron dipole moments are used in selecting the benchmark interaction strengths. We use some asymmetry parameters that have no contribution from standard or CP-even anomalous interactions. Parton showering and detector level simulation is included to make our analysis as realistic as possible. On the whole, we conclude that gauge invariant interaction of strength $\ge 40/\mathrm{Te}{\mathrm{V}}^2$ can be successfully isolated using integrated luminosities in the 1.5-3.0 $\mathrm{a}{\mathrm{b}}^{-1}$ range.

   hep-phPRD(2016)·16 citations
10. 10*

    Scalar field dark matter and the Higgs field

    Orfeu Bertolami🇵🇹 · Catarina Cosme🇵🇹 · João G. Rosa🇵🇹

    We discuss the possibility that dark matter corresponds to an oscillating scalar field coupled to the Higgs boson. We argue that the initial field amplitude should generically be of the order of the Hubble parameter during inflation, as a result of its quasi-de Sitter fluctuations. This implies that such a field may account for the present dark matter abundance for masses in the range $10^{-6}-10^{-4}$ eV, if the tensor-to-scalar ratio is within the range of planned CMB experiments. We show that such mass values can naturally be obtained through either Planck-suppressed non-renormalizable interactions with the Higgs boson or, alternatively, through renormalizable interactions within the Randall-Sundrum scenario, where the dark matter scalar resides in the bulk of the warped extra-dimension and the Higgs is confined to the infrared brane.

    hep-phastro-ph.COgr-qcPLB(2016)·36 citations
11. 11*

    SUSY Dark Matter: Beyond the Standard Paradigm

    Pearl Sandick🇺🇸

    Within the framework of the Minimal Supersymmetric Standard Model (MSSM), we explore a decoupling of the parameters into separate sectors that determine consistency with collider data, the abundance of dark matter, and potential signatures at direct dark matter searches. We consider weak-scale bino-like neutralino dark matter, and find that annihilations via light slepton exchange present a viable mechanism for obtaining the appropriate dark matter abundance assuming a thermal history. Constraints and prospects for discovery of these models are discussed, including the possibility that direct dark matter searches may be sensitive to these models if light squarks exhibit left-right mixing. Differences between the scenarios presented here and the typical expectations for the MSSM are discussed.

    hep-phAIP Conf.Proc.(2016)·0 citations
12. 12*

    How the X(5568) challenges our understanding of QCD

    Feng-Kun Guo🇨🇳 · Ulf-G. Meißner🇩🇪 · Bing-Song Zou🇨🇳

    We discuss the X(5568) particle recently announced by the D0 Collaboration. Several types of models were proposed to explain this structure in the literature. As pointed out by Burns and Swanson (arXiv:1603.04366), none of them provides a satisfactory description of the observation. We provide additional arguments using general properties of QCD, and conclude that the observation of the X(5568), if confirmed, poses serious challenges to our understanding of nonperturbative QCD.

    hep-phhep-exnucl-thCommun.Theor.Phys.(2016)·75 citations
13. 13*

    CP violation in $h\to \tau \tau$ and LFV $h\to \mu \tau$

    Alper Hayreter🇹🇷 · Xiao-Gang He🇨🇳 · German Valencia🇦🇺

    The CMS collaboration has reported a possible lepton flavour violating (LFV) signal $h\to \mu \tau$. Whereas this does not happen in the standard model (SM), we point out that new physics responsible for this type of decay would, in general, also produce charge-parity (CP) violation in $h\to \tau \tau$. We estimate the size of this effect in a model independent manner and find that a large asymmetry, of order 25\%, is allowed by current constraints.

    hep-phhep-exPLB(2016)·14 citations
14. 14*

    Constraints on leptophilic light dark matter from internal heat flux of Earth

    Bhavesh Chauhan🇮🇳 · Subhendra Mohanty🇮🇳

    Dark Matter in Earth intersecting orbits can scatter off the electrons and lose energy, and finally be gravitationally bound to Earth. Eventually they lose enough energy and accumulate at the core. It is assumed that DM annihilates/decays predominantly into Standard Model particles inside Earth. The heat flux from these processes is compared with the experimentally measured value of internal heat flux of Earth which is 44 TW. Assuming steady state between capture and annihilation/decay, we put constraints on the scattering cross section of DM with electrons as a function of their mass. For low mass regions ($<10^{-2}$GeV), these constraints on leptophilic DM are better than ones obtained from direct-detection experiments.

    hep-phPRD(2016)·25 citations
15. 15*

    HBT radii from the multipole Buda-Lund model

    Sándor Lökös🇭🇺 · Máté Csanád🇭🇺 · Boris Tomášik🇸🇰 · Tamás Csörgő🇭🇺

    The Buda-Lund model describes an expanding hydrodynamical system with ellipsoidal symmetry and fits the observed elliptic flow and oscillating HBT radii successfully. The ellipsoidal symmetry can be characterized by the second order harmonics of the transverse momentum distribution, and it can be also observed in the azimuthal oscillation of the HBT radii measured versus the second order reaction plane. The model may have to be changed to describe the experimentally indicated higher order asymmetries. In this paper we detail an extension of the Buda-Lund hydro model to investigate higher order flow harmonics and the triangular dependence of the azimuthally sensitive HBT radii.

    hep-phActa Phys.Polon.Supp.(2016)·0 citations
16. 16*

    Chiral corrections to the $1^{-+}$ exotic meson mass

    Bin Zhou🇨🇳 · Zhi-Feng Sun🇪🇸 · Xiang Liu🇨🇳 · Shi-Lin Zhu🇨🇳

    We first construct the effective chiral Lagrangians for the $1^{-+}$ exotic mesons. With the infrared regularization scheme, we derive the one-loop infrared singular chiral corrections to the ${\pi }_1(1600)$ mass explicitly. We investigate the variation of the different chiral corrections with the pion mass under two schemes. Hopefully, the explicit non-analytical chiral structures will be helpful to the chiral extrapolation of the lattice data from the dynamical lattice QCD simulation of either the exotic light hybrid meson or tetraquark state.

    hep-phhep-latCPC(2017)·2 citations
17. 17*

    Precision physics with pile-up insensitive observables

    Christopher Frye🇺🇸 · Andrew J. Larkoski🇺🇸 · Matthew D. Schwartz🇺🇸 · Kai Yan🇺🇸

    To deepen the search for beyond the Standard Model physics, the Large Hadron Collider is pushing to higher and higher luminosity. At high luminosity, precision physics becomes increasingly difficult due to contamination from additional proton collisions per bunch crossing called pile-up. In recent years, many methods have been developed to cull this excess mostly low-energy radiation away from important signal regions, but it has been unclear if these methods were amenable to systematically-improvable theoretical understanding. In this paper, it is shown that one such method, soft drop jet grooming, has excellent theoretical properties: it is ultra-local, depending on only radiation within a jet, and it is free of non-global logarithms. Calculations of the soft drop jet mass and related observables are presented at next-to-next-to-leading logarithmic accuracy matched to next-to-next-to-leading fixed-order in perturbative Quantum Chromodynamics. Once measured at the Large Hadron Collider, precision comparisons between theory and data can be made, essentially independent of the amount of pile-up contamination.

    hep-phhep-ex83 citations
18. 18*

    Coupling of Hidden Sector

    Wojciech Królikowski🇵🇱

    A hypothetic Hidden Sector of the Universe, consisting of sterile fermions ("sterinos") and sterile mediating bosons ("sterons") of mass dimension 1 (not 2!) - the last described by an antisymmetric tensor field - requires to exist also a scalar isovector and scalar isoscalar in order to be able to construct electroweak invariant coupling (before spontaneously breaking its symmetry).

    hep-phActa Phys.Polon.B(2016)·0 citations
19. 19*

    The decay $\tau \to K^0{K}^{-}{\nu }_{\tau }$ in the extended Nambu-Jona-Lasinio model

    M.K. Volkov🇷🇺 · A.A. Pivovarov🇷🇺

    The full and differential widths of the decay $\tau \to K^0{K}^{-}{\nu }_{\tau }$ are calculated in the framework of the extended Nambu-Jona-Lasinio model. The contributions of the subprocesses with the intermediate vector mesons $\rho$(770) and $\rho$(1450) are taken into account. The obtained results are in satisfactory agreement with the experimental data.

    hep-phMod.Phys.Lett.A(2016)·10 citations
20. 20*

    Masses of open charm and bottom tetraquark states in a relativized quark model

    Qi-Fang Lü🇨🇳 · Yu-Bing Dong🇨🇳

    We study the masses of open charm and bottom tetraquark states within the diquark-antidiquark scenario in the relativized quark model proposed by Godfrey and Isgur. The diquark and antidiquark masses are firstly solved by relativized quark potential, and then treated as the usual antiquark and quark, respectively. The masses of tetraquark states are obtained by solving the Schrödinger-type equation between the new diquark and antidiquark. We find the masses of $sq\bar{b}\bar{q}$ tetraquark configuration are much higher than that of $X(5568)$. This conclusion disfavors the possibility of $X(5568)$ as a tetraquark state within the diquark-antidiquark scenario. Further experimental searches are needed to clarify the nature of the signal observed by D0 collaboration.

    hep-phhep-exnucl-thPRD(2016)·52 citations
21. 21*

    ${\alpha }_s$ and ${\mathrm{V}}_{\mathrm{cs}}$ determination, and CKM unitarity test, from W decays at NNLO

    David d'Enterria🇨🇭 · Matej Srebre🇨🇭

    The hadronic (${\Gamma }_{\mathrm{had}}^{\mathrm{W}}$) and total (${\Gamma }_{\mathrm{tot}}^{\mathrm{W}}$) widths of the W boson, computed at least at next-to-next-to-leading-order (NNLO) accuracy, are combined to derive a new precise prediction for the hadronic W branching ratio ${\mathcal{B}}_{\mathrm{had}}^{\mathrm{W}}\equiv {\Gamma }_{\mathrm{had}}^{\mathrm{W}}/{\Gamma }_{\mathrm{tot}}^{\mathrm{W}}$ = $0.682\pm 0.011_{\mathrm{par}}$, using the experimental Cabibbo-Kobayashi-Maskawa (CKM) matrix elements, or ${\mathcal{B}}_{\mathrm{had}}^{\mathrm{W}}=0.6742\pm 0.0002_{\mathrm{th}}\pm 0.0001_{\mathrm{par}}$ assuming CKM unitarity, with uncertainties dominated by the input parameters of the calculations. Comparing the theoretical predictions and experimental measurements for various W decay observables, the NNLO strong coupling constant at the Z pole, ${\alpha }_s(m_Z)=0.117\pm 0.042_{\exp }\pm 0.004_{\mathrm{th}}\pm 0.001_{\mathrm{par}}$, as well as the charm-strange CKM element, ${\mathrm{V}}_{\mathrm{cs}}$ = 0.973 $\pm$ 0.004${}_{\exp }$ $\pm$ 0.002${}_{\mathrm{par}}$, can be extracted under different assumptions. We also show that W decays provide today the most precise test of CKM unitarity for the 5 quarks lighter than $m_{\mathrm{W}}$, ${\sum }_{u,c,d,s,b}|V_{ij}{|}^2=1.999\pm 0.008_{\exp }\pm 0.001_{\mathrm{th}}$. Perspectives for ${\alpha }_s$ and ${\mathrm{V}}_{\mathrm{cs}}$ extractions from W decays measurements at the LHC and future $e^{+}{e}^{-}$ colliders are presented.

    hep-phhep-exPLB(2016)·31 citations
22. 22*

    Quasinormal modes and the phase structure of strongly coupled matter

    Romuald A. Janik🇵🇱 · Jakub Jankowski🇵🇱 · Hesam Soltanpanahi🇵🇱

    We investigate the poles of the retarded Green's functions of strongly coupled field theories exhibiting a variety of phase structures from a crossover up to different first order phase transitions. These theories are modeled by a dual gravitational description. The poles of the holographic Green's functions appear at the frequencies of the quasinormal modes of the dual black hole background. We focus on quantifying linearized level dynamical response of the system in the critical region of phase diagram. Generically non-hydrodynamic degrees of freedom are important for the low energy physics in the vicinity of a phase transition. For a model with linear confinement in the meson spectrum we find degeneracy of hydrodynamic and non-hydrodynamic modes close to the minimal black hole temperature, and we establish a region of temperatures with unstable non-hydrodynamic modes in a branch of black hole solutions.

    ↳ hep-thhep-phJHEP(2016)·64 citations
23. 23*

    Solar models in light of new high metallicity measurements from solar wind data

    Sunny Vagnozzi🇸🇪 · Katherine Freese🇸🇪 · Thomas H. Zurbuchen🇺🇸

    We study the impact of new metallicity measurements, from solar wind data, on the solar model. The "solar modelling problem" refers to the persisting discrepancy between helioseismological observations and predictions of solar models computed implementing state-of-the-art photospheric abundances. We critically reassess the problem, in particular considering the new set of abundances of von Steiger \& Zurbuchen 2016, determined through the \textit{in situ} collection of solar wind samples from polar coronal holes. This new set of abundances indicates a solar metallicity $Z_{\odot }\ge 0.0196\pm 0.0014$, significantly higher than the currently established value. The new values hint at an abundance of volatile elements (i.e. C, N, O, Ne) close to previous results of Grevesse \& Sauval 1998, whereas the abundance of refractory elements (i.e. Mg, Si, S, Fe) is considerably increased. Using the Linear Solar Model formalism, we determine the variation of helioseismological observables in response to the changes in elemental abundances, in order to explore the consistency of these new measurements with constraints from helioseismology. We find that, for observables that are particularly sensitive to the abundance of volatile elements, in particular the radius of the convective zone boundary (CZB) and the sound speed around the radius of CZB, improved agreement over previous models is obtained. Conversely, the high abundance of refractories correlates with a higher core temperature, resulting in an overproduction of neutrinos and a huge increase in the surface Helium abundance. We conclude that the "solar modelling problem" remains unsolved.

    ↳ astro-ph.SRhep-phApJ(2017)·35 citations
24. 24*

    Connecting the new H.E.S.S. diffuse emission at the Galactic center with the Fermi GeV excess: a combination of millisecond pulsars and heavy dark matter?

    Thomas Lacroix🇫🇷 · Joseph Silk🇫🇷 · Emmanuel Moulin🇫🇷 · Celine Boehm🇬🇧

    The H.E.S.S. collaboration has reported a high-energy spherically symmetric diffuse gamma-ray emission in the inner 50 pc of the Milky Way, up to ~ 50 TeV. Here we propose a leptonic model which provides an alternative to the hadronic scenario presented by the H.E.S.S. collaboration, and connects the newly reported TeV emission to the Fermi-LAT Galactic center GeV excess. Our model relies on a combination of inverse Compton emission from a population of millisecond pulsars---which can account for the GeV excess---and a supermassive black hole-induced spike of heavy (~ 60 TeV) dark matter particles annihilating into electrons with a sub-thermal cross-section. With an up-to-date interstellar radiation field, as well as a standard magnetic field and diffusion set-up, our model accounts for the spectral morphology of the detected emission. Moreover, we show that the dark matter induced emission reproduces the spatial morphology of the H.E.S.S. signal above ~ 10 TeV, while we obtain a slightly more extended component from pulsars at lower energies, which could be used as a prediction for future H.E.S.S. observations.

    ↳ astro-ph.HEastro-ph.COastro-ph.GAhep-phPRD(2016)·18 citations
25. 25*

    Scale-Independent Inflation and Hierarchy Generation

    Pedro G. Ferreira🇬🇧 · Christopher T. Hill🇺🇸 · Graham G. Ross🇬🇧

    We discuss models involving two scalar fields coupled to classical gravity that satisfy the general criteria: (i) the theory has no mass input parameters, (ii) classical scale symmetry is broken only through $-\frac{1}{12}\varsigma {\varphi }^{2}R$ couplings where $\varsigma$ departs from the special conformal value of $1$; (iii) the Planck mass is dynamically generated by the vacuum expectations values (VEVs) of the scalars (iv) there is a stage of viable inflation associated with slow roll in the two--scalar potential; (v) the final vacuum has a small to vanishing cosmological constant and an hierarchically small ratio of the VEVs and the ratio of the scalar masses to the Planck scale. This assumes the paradigm of classical scale symmetry as a custodial symmetry of large hierarchies.

    ↳ hep-thastro-ph.COhep-phPLB(2016)·120 citations
26. 26*

    Origin of dissipative Fermi arc transport in Weyl semimetals

    E. V. Gorbar🇺🇦 · V. A. Miransky🇨🇦 · I. A. Shovkovy🇺🇸 · P. O. Sukhachov🇺🇦

    By making use of a low-energy effective model of Weyl semimetals, we show that the Fermi arc transport is dissipative. The origin of the dissipation is the scattering of the surface Fermi arc states into the bulk of the semimetal. It is noticeable that corresponding scattering rate is nonzero and can be estimated even in a perturbative theory, although in general the reliable calculations of transport properties necessitate a nonperturbative approach. Nondecoupling of the surface and bulk sectors in the low-energy theory of Weyl semimetals invalidates the usual argument of a nondissipative transport due to one-dimensional arc states. This property of Weyl semimetals is in drastic contrast to that of topological insulators, where the decoupling is protected by a gap in the bulk. Within the framework of the linear response theory, we obtain an approximate result for the conductivity due to the Fermi arc states and analyze its dependence on chemical potential, temperature, and other parameters of the model.

    ↳ cond-mat.mes-hallhep-phPRB(2016)·37 citations
27. 27*

    Updated Study of a Precision Measurement of the W Mass from a Threshold Scan Using Polarized ${\mathrm{e}}^{-}$ and ${\mathrm{e}}^{+}$ at ILC

    Graham W. Wilson🇺🇸

    An updated study of measuring the W mass from a polarized threshold scan at ILC is presented with an emphasis on evaluating scan strategies that control experimental systematics. Highly longitudinally polarized beams of electrons and positrons such as are feasible at ILC offer significant advantages in terms of statistical power and in-situ control of background. Eventual experimental precision of around 2 MeV can be envisaged from this technique. Further work on both the accelerator design and theoretical uncertainties will likely be needed to take full advantage of this opportunity.

    ↳ hep-exhep-ph20 citations
28. 28*

    Positron production in collision of heavy nuclei

    I.B. Khriplovich🇷🇺 · D.A. Solovyev🇷🇺

    We consider the electromagnetic production of positron in collision of heavy nuclei, with the simultaneously produced electron captured by one of the nuclei. This cross-section exceeds by about four orders of magnitude the cross-section of $e^{+}{e}^{-}$ production.

    ↳ nucl-thhep-phphysics.atom-ph1 citation
29. 29*

    Vorticity in Heavy-Ion Collisions

    Wei-Tian Deng🇨🇳 · Xu-Guang Huang🇨🇳

    We study the event-by-event generation of flow vorticity in RHIC Au + Au collisions and LHC Pb + Pb collisions by using the HIJING model. Different definitions of the vorticity field and velocity field are considered. A variety of properties of the vorticity are explored, including the impact parameter dependence, the collision energy dependence, the spatial distribution, the event-by-event fluctuation of the magnitude and azimuthal direction, and the time evolution. In addition, the spatial distribution of the flow helicity is also studied.

    ↳ nucl-thhep-lathep-phnucl-exPRC(2016)·241 citations
30. 30*

    Spectral splits of neutrinos as a BCS-BEC crossover type phenomenon

    Y. Pehlivan🇹🇷 · A. L. Subaşı🇹🇷 · N. Ghazanfari🇹🇷 · S. Birol🇹🇷 · H. Yüksel🇹🇷

    We show that the spectral split of a neutrino ensemble which initially consists of electron type neutrinos, is analogous to the BCS-BEC crossover already observed in ultra cold atomic gas experiments. Such a neutrino ensemble mimics the deleptonization burst of a core collapse supernova. Although these two phenomena belong to very different domains of physics, the propagation of neutrinos from highly interacting inner regions of the supernova to the vacuum is reminiscent of the evolution of Cooper pairs between weak and strong interaction regimes during the crossover. The Hamiltonians and the corresponding many-body states undergo very similar transformations if one replaces the pair quasispin of the latter with the neutrino isospin of the former.

    ↳ astro-ph.HEcond-mat.quant-gashep-phnucl-thPRD(2017)·19 citations
31. 31*

    Blast-wave model description of the HBT radii measured in $pp$ collisions at the LHC energies

    Wojciech Florkowski🇵🇱

    Blast-wave model is applied to describe the Hanbury-Brown--Twiss (HBT) radii of pionic systems produced in pp collisions at the LHC energies.

    ↳ nucl-thhep-phActa Phys.Polon.B(2016)·4 citations
32. 32*

    Foundations of Strangeness Nuclear Physics derived from chiral Effective Field Theory

    Ulf-G. Meißner🇩🇪 · Johann Haidenbauer🇩🇪

    Dense compact objects like neutron stars or black holes have always been one of Gerry Brown's favorite research topics. This is closely related to the effects of strangeness in nuclear physics. Here, we review the chiral Effective Field Theory approach to interactions involving nucleons and hyperons, the possible existence of strange dibaryons, the fate of hyperons in nuclear matter and the present status of three-body forces involving hyperons and nucleons.

    ↳ nucl-thhep-lathep-phnucl-exIJMPE(2017)·5 citations
33. 33*

    Continuum limit of the $D$ meson, $D_s$ meson and charmonium spectrum from $N_f=2+1+1$ twisted mass lattice QCD

    Krzysztof Cichy🇩🇪 · Martin Kalinowski🇩🇪 · Marc Wagner🇩🇪

    We compute masses of $D$ meson, $D_s$ meson and charmonium states using $N_f=2+1+1$ Wilson twisted mass lattice QCD. All results are extrapolated to physical light quark masses, physical strange and charm quark masses and to the continuum. Our analysis includes states with spin $J=0,1,2$, parity $\mathcal{P}=-,+$ and in case of charmonium also charge conjugation $\mathcal{C}=-,+$. Computations are based on a large set of quark-antiquark meson creation operators. We investigate and quantify all sources of systematic errors, including fitting range uncertainties, finite volume effects, isospin breaking effects and the choice of the fitting ansatz for the combined chiral and continuum extrapolation such that the resulting meson masses can be compared directly and in a meaningful way to experimental results. Within combined statistical and systematic errors, which are between below two per mille and three percent, our results agree with available experimental results for most of the states. In the few cases where we observe discrepancies, we discuss possible reasons.

    ↳ hep-lathep-exhep-phPRD(2016)·40 citations
34. 34*

    Reconstructing WIMP properties through an interplay of signal measurements in direct detection, Fermi-LAT, and CTA searches for dark matter

    Leszek Roszkowski🇵🇱 · Enrico Maria Sessolo🇵🇱 · Sebastian Trojanowski🇵🇱 · Andrew J. Williams🇵🇱

    We examine the projected ability to reconstruct the mass, scattering, and annihilation cross section of dark matter in the new generation of large underground detectors, XENON-1T, SuperCDMS, and DarkSide-G2, in combination with diffuse gamma radiation from expected 15 years of data from Fermi-LAT observation of 46 local spiral dwarf galaxies and projected CTA sensitivity to a signal from the Galactic Center. To this end we consider several benchmark points spanning a wide range of WIMP mass, different annihilation final states, and large enough event rates to warrant detection in one or more experiments. As previously shown, below some 100 GeV only direct detection experiments will in principle be able to reconstruct the WIMP mass well. This may, in case a signal at Fermi-LAT is also detected, additionally help restricting \sigma v and the allowed decay branching rates. In the intermediate range between some 100 GeV and up a few hundred GeV, direct and indirect detection experiments can be used in complementarity to ameliorate the respective determinations, which in individual experiments can at best be rather poor, thus making the WIMP reconstruction in this mass range very challenging. At large WIMP mass, ~1 TeV, CTA will have the ability to reconstruct mass, annihilation cross section, and the allowed decay branching rates to very good precision for the ${\tau }^{+}{\tau }^{-}$ or purely leptonic final state, good for the $W^{+}{W}^{-}$ case, and rather poor for $b\bar{b}$. A substantial improvement can potentially be achieved by reducing the systematic uncertainties, increasing exposure, or by an additional measurement at Fermi-LAT that would help reconstruct the annihilation cross section and the allowed branching fractions to different final states.

    ↳ astro-ph.COhep-phJCAP(2016)·19 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.