Thu·Nov 2, 2017Thursday·November 2, 2017

1. 01*

   $pp\to A\to Zh$ and the wrong-sign limit of the Two-Higgs-Doublet Model

   Pedro M. Ferreira🇵🇹 · Stefan Liebler🇩🇪 · Jonas Wittbrodt🇩🇪

   We point out the importance of the decay channels $A\to Zh$ and $H\to VV$ in the wrong-sign limit of the Two-Higgs-Doublet Model (2HDM) of type II. They can be the dominant decay modes at moderate values of $\tan \beta$, even if the (pseudo)scalar mass is above the threshold where the decay into a pair of top quarks is kinematically open. Accordingly, large cross sections $pp\to A\to Zh$ and $pp\to H\to VV$ are obtained and currently probed by the LHC experiments, yielding conclusive statements about the remaining parameter space of the wrong-sign limit. In addition, mild excesses - as recently found in the ATLAS analysis $b\bar{b}\to A\to Zh$ - could be explained. The wrong-sign limit makes other important testable predictions for the light Higgs boson couplings.

   hep-phPRD(2018)·28 citations
2. 02*

   A Very Heavy Sneutrino as Viable Thermal Dark Matter Candidate in $U(1{)}^{\prime }$ Extensions of the MSSM

   Felipe A. Gomes Ferreira🇩🇪 · Manuel Drees🇩🇪

   We study the Standard Model singlet ("right-handed") sneutrino ${\tilde{\nu }}_R$ dark matter in a class of $U(1{)}^{\prime }$ extensions of the MSSM that originate from the breaking of the $E_6$ gauge group. These models, which are referred to as UMSSM, contain three right--handed neutrino superfields plus an extra gauge boson $Z^{\prime }$ and an additional SM singlet Higgs with mass $\simeq M_{Z^{\prime }}$, together with their superpartners. In the UMSSM the right sneutrino is charged under the extra $U(1{)}^{\prime }$ gauge symmetry; it can therefore annihilate via gauge interactions. In particular, for $M_{{\tilde{\nu }}_R}\simeq M_{Z^{\prime }}/2$ the sneutrinos can annihilate by the exchange of (nearly) on--shell gauge or Higgs bosons. We focus on this region of parameter space. For some charge assignment we find viable thermal ${\tilde{\nu }}_R$ dark matter for mass up to $\sim 43$ TeV. This is the highest mass of a good thermal dark matter candidate in standard cosmology that has so far been found in an explicit model. Our result can also be applied to other models of spin$-0$ dark matter candidates annihilating through the resonant exchange of a scalar particle. These models cannot be tested at the LHC, nor in present or near--future direct detection experiments, but could lead to visible indirect detection signals in future Cherenkov telescopes.

   hep-phJHEP(2019)·5 citations
3. 03*

   Characterizing simplified models for heavy Higgs decays to supersymmetric particles

   Suchita Kulkarni🇦🇹 · Lukas Lechner🇦🇹

   The search for heavy Higgs bosons is an important step to probe the parameter space of the Minimal Supersymmetric Standard Model. In this work, we classify all possible decay modes of the supersymmetric heavy Higgs boson using the SModelS framework. We work within the phenomenological MSSM and use the ATLAS pMSSM study as our viable parameter space. We find that for a bino-like and higgsino-like LSP, a significant region of the parameter space results in mono-$X$ ($X$ = $h$, $W$, $Z$) final states. For wino-like LSPs, we demonstrate the existence of displaced vertex signatures with a large signal cross section. Finally, we argue that by covering the mono-$X$ final states, a large part of heavy Higgs decays can be tested at the LHC.

   hep-phhep-ex9 citations
4. 04*

   Nonpolynomial Higgs interactions and vacuum stability

   René Sondenheimer🇩🇪

   The possible violation of the conventional lower Higgs mass stability bound by the discovered Higgs boson has far reaching consequences within particle physics and cosmology. We discuss the possibility that nonpolynomial bare interactions seeded at some high-momentum scale can considerably diminish the lower Higgs mass bound without introducing a metastability in the Higgs effective potential. For this, we classify various deformations of the usual quartic bare potential regarding their impact on stable IR physics. We perform the analysis in a large $N_{\mathrm{f}}$ expansion, addressing the convergence of the obtained results by taking $1/N_{\mathrm{f}}$ corrections into account as well. In addition, we investigate the renormalization group flow of the scalar potential on a nonperturbative level. Within these approximations, we are able to identify bare potentials that lead to Higgs masses below stability mass bounds obtained from finite-order polynomial bare interactions without introducing a metastability in the effective potential.

   hep-phhep-thEPJC(2019)·36 citations
5. 05*

   Analysis of a Dilaton EFT for Lattice Data

   Thomas Appelquist🇺🇸 · James Ingoldby🇺🇸 · Maurizio Piai🇬🇧

   In a recent paper, we developed and applied a dilaton-based effective field theory (EFT) to the analysis of lattice-simulation data for a class of confining gauge theories with near-conformal infrared behavior. It was employed there at the classical level to the SU(3) gauge theory with eight Dirac fermions in the fundamental representation. Here, we explore the structure of the EFT further. We examine its application to lattice data (newly updated) for the SU(3) theory with eight Dirac fermions in the fundamental representation, and the SU(3) theory with two Dirac fermions in the sextet representation. In each case, we determine additional fit parameters and discuss uncertainties associated with extrapolation to zero fermion mass. We highlight universal features, study the EFT at the quantum loop level and discuss the importance of future lattice simulations.

   hep-phhep-latJHEP(2018)·76 citations
6. 06*

   Single-diffractive dijet production at high energies within the $k_t$ -factorization approach

   Marta Luszczak🇵🇱 · Antoni Szczurek🇵🇱

   We discuss single-diffractive production of dijets. The cross section is calculated for the first time in the $k_t$-factorization approach, neglecting transverse momentum of the pomeron. We use Kimber-Martin-Ryskin unintegrated parton (gluon, quark, antiquark) distributions (UPDF) both in the proton as well as in the pomeron or subleading reggeon. The UPDFs are calculated based on conventional MMHT2014nlo PDFs in the proton and H1 collaboration diffractive PDFs used previously in the analysis of diffractive structure function and dijets at HERA. We try to describe the existing data from Tevatron and make detailed predictions for possible LHC measurements.

   hep-ph0 citations
7. 07*

   Constraining scalar resonances with top-quark pair production at the LHC

   Diogo Buarque Franzosi🇩🇪 · Federica Fabbri🇮🇹 · Steffen Schumann🇩🇪

   Constraints on models which predict resonant top-quark pair production at the LHC are provided via a reinterpretation of the Standard Model (SM) particle level measurement of the top-anti-top invariant mass distribution, $m(t\bar{t})$. We make use of state-of-the-art Monte Carlo event simulation to perform a direct comparison with measurements of $m(t\bar{t})$ in the semi-leptonic channels, considering both the boosted and the resolved regime of the hadronic top decays. A simplified model to describe various scalar resonances decaying into top-quarks is considered, including CP-even and CP-odd, color-singlet and color-octet states, and the excluded regions in the respective parameter spaces are provided.

   hep-phJHEP(2018)·17 citations
8. 08*

   Delbruck scattering in small scattering angle region

   Taekoon Lee🇰🇷

   The scattering of photons of x-ray energy off a Coulomb field in very forward scattering region may be thought as the refraction effect due to the Coulomb field. The cross section of the scattering can be computed from the photon bending angle obtained in geometrical optics. Its dependence on the fine structure constant is nonanalytic and softer than would the box diagrams of Delbruck scattering suggest. The refractive scattering is a nonlocal effect occurring over the distance scale of the impact parameter, and therefore may not be described by the single-box diagrams. We suggest that the scattering cross section is a consequence of the sum of the asymptotic series of the multi-box diagrams.

   hep-phphysics.atom-ph2 citations
9. 09*

   Diffractive Scattering: Problems in Theory and Praxis

   V. Petrov🇷🇺

   A concise survey of problems in modern strong interaction physics at high energies is given.

   hep-ph2 citations
10. 10*

    ${\eta }_c^{\prime }$ Hadroproduction at Next-to-Leading Order and its Relevance to ${\psi }^{\prime }$ Production

    Jean-Philippe Lansberg🇫🇷 · Hua-Sheng Shao🇫🇷 · Hong-Fei Zhang🇨🇳

    We proceed to the first study of ${\eta }_c^{\prime }$ prompt hadroproduction at next-to-leading order in ${\alpha }_s$. Based on heavy-quark-spin symmetry, which is systematically used in quarkonium-production phenomenology, we demonstrate that prompt ${\eta }_c^{\prime }$ can be studied at the LHC with the existing data. We emphasize its relevance to constrain ${\psi }^{\prime }$ production, in the same way as the first prompt ${\eta }_c^{\prime }$ data at the LHC lately strongly impacted the phenomenology of $J/\psi$ studies.

    hep-phhep-exnucl-exnucl-thPLB(2018)·31 citations
11. 11*

    Hadronic light-by-light contribution to $(g-2{)}_{\mu }$: a dispersive approach

    Gilberto Colangelo🇨🇭 · Martin Hoferichter🇺🇸 · Massimiliano Procura🇦🇹 · Peter Stoffer🇺🇸

    After a brief introduction on ongoing experimental and theoretical activities on $(g-2{)}_{\mu }$, we report on recent progress in approaching the calculation of the hadronic light-by-light contribution with dispersive methods. General properties of the four-point function of the electromagnetic current in QCD, its Lorentz decomposition and dispersive representation are discussed. On this basis a numerical estimate for the pion box contribution and its rescattering corrections is obtained. We conclude with an outlook for this approach to the calculation of hadronic light-by-light.

    hep-phhep-latEPJ Web Conf.(2018)·13 citations
12. 12*

    Inferences on the Higgs Boson and Axion Masses through a Maximum Entropy Principle

    Alexandre Alves🇧🇷 · Alex G. Dias🇧🇷 · Roberto da Silva🇧🇷

    The Maximum Entropy Principle (MEP) is a method that can be used to infer the value of an unknown quantity in a set of probability functions. In this work we review two applications of MEP: one giving a precise inference of the Higgs boson mass value; and the other one allowing to infer the mass of the axion. In particular, for the axion we assume that it has a decay channel into pairs of neutrinos, in addition to the decay into two photons. The Shannon entropy associated to an initial ensemble of axions decaying into photons and neutrinos is then built for maximization.

    hep-ph1 citation
13. 13*

    Likelihood Analysis of the Sub-GUT MSSM in Light of LHC 13-TeV Data

    J.C. Costa🇬🇧 · E. Bagnaschi🇩🇪 · K. Sakurai🇵🇱 · M. Borsato🇪🇸 · O. Buchmueller🇬🇧 · M. Citron🇬🇧 · A. De Roeck🇨🇭 · M.J. Dolan🇦🇺 · J.R. Ellis🇬🇧 · H. Flächer🇬🇧 · S. Heinemeyer🇪🇸 · M. Lucio🇪🇸 and 4 other authors

    We describe a likelihood analysis using MasterCode of variants of the MSSM in which the soft supersymmetry-breaking parameters are assumed to have universal values at some scale $M_{in}$ below the supersymmetric grand unification scale $M_{GUT}$, as can occur in mirage mediation and other models. In addition to $M_{in}$, such `sub-GUT' models have the 4 parameters of the CMSSM, namely a common gaugino mass $m_{1/2}$, a common soft supersymmetry-breaking scalar mass $m_0$, a common trilinear mixing parameter $A$ and the ratio of MSSM Higgs vevs $\tan \beta$, assuming that the Higgs mixing parameter $\mu >0$. We take into account constraints on strongly- and electroweakly-interacting sparticles from $\sim 36$/fb of LHC data at 13 TeV and the LUX and 2017 PICO, XENON1T and PandaX-II searches for dark matter scattering, in addition to the previous LHC and dark matter constraints as well as full sets of flavour and electroweak constraints. We find a preference for $M_{in}\sim 10^5$ to $10^9$ GeV, with $M_{in}\sim M_{GUT}$ disfavoured by $\Delta {\chi }^2\sim 3$ due to the $\mathrm{BR}(B_{s,d}\to {\mu }^{+}{\mu }^{-})$ constraint. The lower limits on strongly-interacting sparticles are largely determined by LHC searches, and similar to those in the CMSSM. We find a preference for the LSP to be a Bino or Higgsino with $\widetilde{{\chi }_1^0}\sim 1$ TeV, with annihilation via heavy Higgs bosons $H/A$ and stop coannihilation, or chargino coannihilation, bringing the cold dark matter density into the cosmological range. We find that spin-independent dark matter scattering is likely to be within reach of the planned LUX-Zeplin and XENONnT experiments. We probe the impact of the $(g-2{)}_{\mu }$ constraint, finding similar results whether or not it is included.

    hep-phastro-ph.HEhep-exEPJC(2018)·44 citations
14. 14*

    An overview of DarkBit, the GAMBIT dark matter module

    Jonathan M. Cornell (for the GAMBIT collaboration)🇨🇦

    In this conference paper, I give an overview of the capabilities of DarkBit, a module of the GAMBIT global fitting code that calculates a range of dark matter observables and corresponding experimental likelihood functions. Included in the code are limits from the dark matter relic density, multiple direct detection experiments, and indirect searches in gamma-rays and neutrinos. I discuss the capabilities of the code, and then present recent results of GAMBIT scans of the parameter space of the minimal supersymmetric standard model, with a focus on sensitivities of future dark matter searches to the current best fit regions.

    hep-phastro-ph.HEastro-ph.IMJ.Phys.Conf.Ser.(2020)·4 citations
15. 15*

    Electromagnetic and Axial-Vector Form Factors of the Quarks and Nucleon

    Harleen Dahiya🇮🇳 · Monika Randhawa🇮🇳

    In light of the improved precision of the experimental measurements and enormous theoretical progress, the nucleon form factors have been evaluated with an aim to understand how the static properties and dynamical behavior of nucleons emerge from the theory of strong interactions between quarks. We have analysed the vector and axial-vector nucleon form factors ($G_{E,M}^{p,n}(Q^2)$ and $G_A^{p,n}(Q^2)$) using the spin observables in the chiral constituent quark model ($\chi$CQM) which has made a significant contribution to the unraveling of the internal structure of the nucleon in the nonperturbative regime. We have also presented a comprehensive analysis of the flavor decomposition of the form factors ($G_E^q(Q^2)$, $G_M^q(Q^2)$ and $G_A^q(Q^2)$for $q=u,d,s$) within the framework of $\chi$CQM with emphasis on the extraction of the strangeness form factors which are fundamental to determine the spin structure and test the chiral symmetry breaking effects in the nucleon. The $Q^2$ dependence of the vector and axial-vector form factors of the nucleon has been studied using the conventional dipole form of parametrization. The results are in agreement with the available experimental data.

    hep-phInt.J.Mod.Phys.A(2017)·6 citations
16. 16*

    New nonperturbative scales and glueballs in confining supersymmetric gauge theories

    Mohamed M. Anber🇺🇸 · Erich Poppitz🇨🇦

    We show that new nonperturbative scales exist in four-dimensional $\mathcal{N}$$=$$1$ super-Yang-Mills theory compactified on a circle, with an iterated-exponential dependence on the inverse gauge coupling. The lightest states with the quantum numbers of four-dimensional glueballs are nonrelativistic bound states of dual Cartan gluons and superpartners, with binding energy equal to $e^{-e^{1/g^2}}$ in units of the confining mass gap. Focusing on $SU(2)$ gauge group, we construct the nonrelativistic effective theory, show that the lightest glueball/glueballino states fill a chiral supermultiplet, and determine their "doubly-nonperturbative" binding energy. The iterated-exponential dependence on the gauge coupling is due to nonperturbative couplings in the long distance theory, $\lambda \sim e^{-\frac{1}{g^2}}$, which are responsible for attractive interactions, in turn producing exponentially small, $\sim e^{-\frac{1}{\lambda }}$, effects.

    ↳ hep-thhep-lathep-phJHEP(2018)·9 citations
17. 17*

    Statistical Angles on the Lattice QCD Signal-to-Noise Problem

    Michael L. Wagman🇺🇸

    The theory of quantum chromodynamics (QCD) encodes the strong interactions that bind quarks and gluons into nucleons and that bind nucleons into nuclei. Predictive control of QCD would allow nuclear structure and reactions as well as properties of supernovae and neutron stars to be theoretically studied from first principles. Lattice QCD can represent generic QCD predictions in terms of well-defined path integrals, but the sign and signal-to-noise problems have obstructed lattice QCD calculations of large nuclei and nuclear matter in practice. This thesis presents a statistical study of lattice QCD correlation functions, with a particular focus on characterizing the structure of the noise associated with quantum fluctuations. The signal-to-noise problem in baryon correlation functions is demonstrated to arise from a sign problem associated with Monte Carlo sampling of complex correlation functions. The phases of complex correlation functions are analyzed in the framework of circular statistics, and the time evolution of the phase is shown to resemble a heavy-tailed random walk on the unit circle. Building on these observations, a new technique called phase reweighting is investigated that involves calculations of phase differences over fixed-length time intervals. Phase reweighting allows results for hadronic observables to be extracted from large-time correlation functions with constant signal-to-noise ratios. The signal-to-noise problem re-emerges as the length of the phase-difference interval is increased. Applications of phase reweighting to meson, baryon, and two-baryon systems are discussed.

    ↳ hep-lathep-ph12 citations
18. 18*

    Searches for supersymmetry

    Andrea Ventura (on behalf of the ATLAS and CMS Collaborations)🇮🇹

    New and recent results on Supersymmetry searches are shown for the ATLAS and the CMS experiments. Analyses with about 36 fb${}^{-1}$ are considered for searches concerning light squarks and gluinos, direct pair production of 3${}^{rd}$ generation squarks, electroweak production of charginos, neutralinos, sleptons, R-parity violating scenarios and long-lived particles.

    ↳ hep-exhep-phInt.J.Mod.Phys.Conf.Ser.(2018)·9 citations
19. 19*

    Exploring the Properties of Choked Gamma-Ray Bursts with IceCube's High Energy Neutrinos

    Peter B. Denton🇩🇰 · Irene Tamborra🇩🇰

    Long duration gamma-ray bursts (GRBs) have often been considered as the natural evolution of some core-collapse supernova (CCSN) progenitors. However, the fraction of CCSNe linked to astrophysical jets and their properties are still poorly constrained. While any successful astrophysical jet harbored in a CCSN should produce high energy neutrinos, photons may be able to successfully escape the stellar envelope only for a fraction of progenitors, possibly leading to the existence of high-luminosity, low-luminosity and not-electromagnetically bright ("choked") GRBs. By postulating a CCSN-GRB connection, we accurately model the jet physics within the internal-shock GRB model and assume scaling relations for the GRB parameters that depend on the Lorentz boost factor $\Gamma$. The IceCube high energy neutrino flux is then employed as an upper limit of the neutrino background from electromagnetically bright and choked GRBs to constrain the jet and the progenitor properties. The current IceCube data set is compatible with up to $1\%$ of all CCSNe harboring astrophysical jets. Interestingly, those jets are predominantly choked. Our findings suggest that neutrinos can be powerful probes of the burst physics and can provide major insights on the CCSN-GRB connection.

    ↳ astro-ph.HEhep-phApJ(2018)·55 citations
20. 20*

    Imprints of neutrino-pair flavor conversions on nucleosynthesis in ejecta from neutron-star merger remnants

    Meng-Ru Wu🇹🇼 · Irene Tamborra🇩🇰 · Oliver Just🇯🇵 · Hans-Thomas Janka🇩🇪

    The remnant of neutron star mergers is dense in neutrinos. By employing inputs from one hydrodynamical simulation of a binary neutron star merger remnant with a black hole of $3M_{\odot }$ in the center, dimensionless spin parameter $0.8$ and an accretion torus of $0.3M_{\odot }$, the neutrino emission properties are investigated as the merger remnant evolves. Initially, the local number density of ${\bar{\nu }}_e$ is larger than that of ${\nu }_e$ everywhere above the remnant. Then, as the torus approaches self-regulated equilibrium, the local abundance of neutrinos overcomes that of antineutrinos in a funnel around the polar region. The region where the fast pairwise flavor conversions can occur shrinks accordingly as time evolves. Still, we find that fast flavor conversions do affect most of the neutrino-driven ejecta. Assuming that fast flavor conversions lead to flavor equilibration, a significant enhancement of nuclei with mass numbers $A>130$ is found as well as a change of the lanthanide mass fraction by more than a factor of a thousand. Our findings hint towards a potentially relevant role of neutrino flavor oscillations for the prediction of the kilonova (macronova) lightcurves and motivate further work in this direction.

    ↳ astro-ph.HEhep-phnucl-thPRD(2017)·136 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.