Thu·Apr 6, 2017Thursday·April 6, 2017

1. 01*

   First-principle calculations of Dark Matter scattering off light nuclei

   C. Körber🇩🇪 · A. Nogga🇩🇪 · J. de Vries🇳🇱

   We study the scattering of Dark Matter particles off various light nuclei within the framework of chiral effective field theory. We focus on scalar interactions and include one- and two-nucleon scattering processes whose form and strength are dictated by chiral symmetry. The nuclear wave functions are calculated from chiral effective field theory interactions as well and we investigate the convergence pattern of the chiral expansion in the nuclear potential and the Dark Matter-nucleus currents. This allows us to provide a systematic uncertainty estimate of our calculations. We provide results for ${}^2$H, ${}^3$H, and ${}^3$He nuclei which are theoretically interesting and the latter is a potential target for experiments. We show that two-nucleon currents can be systematically included but are generally smaller than predicted by power counting and suffer from significant theoretical uncertainties even in light nuclei. We demonstrate that accurate high-order wave functions are necessary in order to incorporate two-nucleon currents. We discuss scenarios in which one-nucleon contributions are suppressed such that higher-order currents become dominant.

   hep-phnucl-thPRC(2017)·60 citations
2. 02*

   Doublet-triplet dark matter with neutrino masses

   Amalia Betancur🇨🇴 · Robinson Longas🇨🇴 · Oscar Zapata🇨🇴

   We consider a dark matter (DM) model that arises from the interplay of two simplified dark matter models, namely the doublet-triplet fermion model and the doublet-triplet scalar model. Despite being excellent exponents of the WIMP paradigm, the physics related to DM in each of these models fails at the same time to account for neutrino masses. It turns out that from the combination of these two models it is possible to generate neutrino masses at one-loop level in the four topologies that are realizations of the Weinberg operator for neutrino masses at one-loop. In this work, we combine both models focusing mostly on fermionic dark matter lying at the electroweak scale. We analyze the impact of the extra charged fields on the Higgs diphoton decay and find that, thanks to the presence of the charged scalars, it is possible to have a viable DM region at the electroweak scale.

   hep-phPRD(2017)·12 citations
3. 03*

   Masses of Scalar and Axial-Vector B Mesons Revisited

   Hai-Yang Cheng🇹🇼 · Fu-Sheng Yu🇨🇳

   The SU(3) quark model encounters a great challenge in describing even-parity mesons. Specifically, the $q\bar{q}$ quark model has difficulties in understanding the light scalar mesons below 1 GeV, scalar and axial-vector charmed mesons and $1^{+}$ charmonium-like state $X(3872)$. A common wisdom for the resolution of these difficulties lies on the coupled channel effects which will distort the quark model calculations. In this work, we focus on the near mass degeneracy of scalar charmed mesons, $D_{s0}^{\ast }$ and $D_0^{\ast 0}$, and its implications. Within the framework of heavy meson chiral perturbation theory, we show that near degeneracy can be qualitatively understood as a consequence of self-energy effects due to strong coupled channels. Quantitatively, the closeness of $D_{s0}^{\ast }$ and $D_0^{\ast 0}$ masses can be implemented by adjusting two relevant strong couplings and the renormalization scale appearing in the loop diagram. Then this in turn implies the mass similarity of $B_{s0}^{\ast }$ and $B_0^{\ast 0}$ mesons. The $P_0^{\ast }{P}_1^{\prime }$ interaction with the Goldstone boson is crucial for understanding the phenomenon of near degeneracy. Based on heavy quark symmetry in conjunction with corrections from QCD and $1/m_Q$ effects, we obtain the masses of $B_{(s)0}^{\ast }$ and $B_{(s)1}^{\prime }$ mesons, for example, $M_{B_{s0}^{\ast }}=(5715\pm 1)\mathrm{MeV}+\delta {\Delta }_S$, $M_{B_{s1}^{\prime }}=(5763\pm 1)\mathrm{MeV}+\delta {\Delta }_S$ with $\delta {\Delta }_S$ being $1/m_Q$ corrections. We find that the predicted mass difference of 48 MeV between $B_{s1}^{\prime }$ and $B_{s0}^{\ast }$ is larger than that of $20\sim 30$ MeV inferred from the relativistic quark models, whereas the difference of 15 MeV between the central values of $M_{B_{s1}^{\prime }}$ and $M_{B_1^{\prime }}$ is much smaller than the quark model expectation of $60-100$ MeV.

   hep-phhep-exEPJC(2017)·40 citations
4. 04*

   Dynamical spin effects in the pion

   M. Ahmady🇨🇦 · F. Chishtie🇵🇰 · R. Sandapen🇨🇦

   We take into account dynamical spin effects in the holographic light-front pion wavefunction in order to predict the pion radius, decay constant, the pion electromagnetic and photon-to-pion transition form factors. We report a striking improvement in the description of all data.

   hep-phAIP Conf.Proc.(2017)·1 citation
5. 05*

   Anomalous Higgs Yukawa Couplings and Recent LHC Data

   Arindam Das🇰🇷 · Nobuhito Maru🇯🇵 · Nobuchika Okada🇺🇸

   Very recently, the CMS collaboration has reported a search for the production for a Standard Model (SM) Higgs boson in association with a top quark pair ($tbartH$) at the LHC Run-2 and a best fit $tbartH$ yield of $1.5pm0.5$ times the SM prediction with an observed significance of $3.3sigma$. We study a possibility of whether or not this observed deviation can be explained by anomalous Higgs Yukawa couplings with the top and the bottom quarks, along with the LHC Run-1 data for the Higgs boson properties. We find that anomalous top and bottom Yukawa couplings with about $0-20$% and $10-40$% reductions from their SM values, respectively, can simultaneously fit the recent CMS result and the LHC Run-1 data.

   hep-ph6 citations
6. 06*

   Effect of magnetic field on dilepton production in a hot plasma

   Aritra Bandyopadhyay🇮🇳 · S. Mallik🇮🇳

   Noncentral collision of heavy ions can generate large magnetic field in its neighbourhood. We describe a method to calculate the effect of this field on the dilepton emission rate from the colliding region, when it reaches thermal equilibrium. It is calculated in the real time method of thermal field theory. We find that the rate is affected significantly only for lower momenta of dileptons.

   hep-phPRD(2017)·38 citations
7. 07*

   Investigating the excited ${\Omega }_c^0$ states through ${\Xi }_{c}K$ and ${\Xi }_c^{{}^{\prime }}K$ decay channels

   Hongxia Huang🇨🇳 · Jialun Ping🇨🇳 · Fan Wang🇨🇳

   Inspired by the five newly observed ${\Omega }_c^0$ states by the LHCb detector, we study the ${\Omega }_c^0$ states as the $S-$wave molecular pentaquarks with $I=0$, $J^P={\frac{1}{2}}^{-}$, ${\frac{3}{2}}^{-}$, and ${\frac{5}{2}}^{-}$ by solving the RGM equation in the framework of chiral quark model. Both the energies and the decay widths are obtained in this work. Our results suggest that ${\Omega }_c(3119{)}^0$ can be explained as an $S-$wave resonance state of $\Xi D$ with $J^P={\frac{1}{2}}^{-}$, and the decay channels are the $S-$wave ${\Xi }_{c}K$ and ${\Xi }_c^{{}^{\prime }}K$ . Other reported ${\Omega }_c^0$ states cannot be obtained in our present calculation. Another ${\Omega }_c^0$ state with much higher mass 3533 MeV with $J^P={\frac{5}{2}}^{-}$ is also obtained. In addition, the calculation is extended to the ${\Omega }_b^0$ states, similar results as that of ${\Omega }_c^0$ are obtained.

   hep-phhep-exPRD(2018)·63 citations
8. 08*

   Inhomogeneous charged pion condensation in chiral asymmetric dense quark matter in the framework of NJL${}_2$ model

   T. G. Khunjua🇷🇺 · K. G. Klimenko🇷🇺 · R. N. Zhokhov🇷🇺 · V. C. Zhukovsky🇷🇺

   In this paper we investigate the phase structure of a (1+1)-dimensional quark model with four-quark interaction and in the presence of baryon (${\mu }_B$), isospin (${\mu }_I$) and chiral isospin (${\mu }_{I5}$) chemical potentials. Spatially inhomogeneous chiral density wave (for chiral condensate) and single wave (for charged pion condensate) approaches are used. It is established that in the large-$N_c$ limit ($N_c$ is the number of colored quarks) there exists a duality correspondence between the chiral symmetry breaking phase and the charged pion condensation (PC) one. Moreover, it is shown that inhomogeneous charged PC phase with nonzero baryon density is induced in the model by arbitrary small values of the chemical potential ${\mu }_{I5}$ (for a rather large region of ${\mu }_B$ and ${\mu }_I$).

   hep-phhep-thPRD(2017)·45 citations
9. 09*

   Radiative Light Dark Matter

   Athanasios Dedes🇬🇷 · Dimitrios Karamitros🇬🇷 · Apostolos Pilaftsis🇬🇧

   We present a Peccei-Quinn (PQ)-symmetric two-Higgs doublet model that naturally predicts a fermionic singlet dark matter in the mass range 10 keV-1 GeV. The origin of the smallness of the mass of this light singlet fermion arises predominantly at the one-loop level, upon soft or spontaneous breakdown of the PQ symmetry via a complex scalar field in a fashion similar to the so-called Dine-Fischler-Sredniki-Zhitnitsky axion model. The mass generation of this fermionic Radiative Light Dark Matter (RLDM) requires the existence of two heavy vector-like SU(2) isodoublets, which are not charged under the PQ symmetry. We show how the RLDM can be produced via the freeze-in mechanism, thus accounting for the missing matter in the Universe. Finally, we briefly discuss possible theoretical and phenomenological implications of the RLDM model for the strong CP problem and the CERN Large Hadron Collider (LHC).

   hep-phPRD(2017)·9 citations
10. 10*

    Distinguishing Dirac and Majorana neutrinos with astrophysical fluxes

    J. Barranco🇲🇽 · D. Delepine🇲🇽 · M. Napsuciale🇲🇽 · A. Yebra🇲🇽

    Massive neutrinos can have helicity $s_{\parallel }\ne -1$. Neutrino helicity changes when the neutrino interacts with an external magnetic field and it is possible that the left-handed neutrinos born inside the Sun or a supernova could leave their sources with a different helicity. Since Dirac and Majorana neutrinos have different cross sections in the scattering on electrons for different neutrino helicities, a change in the final neutrino helicity may generate a different number of events and spectra in terrestrial detectors when astrophysical neutrinos have travelled regions with strong magnetic fields. In this work, we show that looking for these effects in solar neutrinos, it could be possible to set bounds in the neutrino properties such as the neutrino magnetic moment. Furthermore, for neutrinos coming from a supernova, we show that even in the case of an extremely small neutrino magnetic moment, ${\mu }_{\nu }\sim 10^{-19}{\mu }_B$, there will be measurable differences in both the number of events and in the spectra of Majorana and Dirac neutrinos.

    hep-phJ.Phys.G(2020)·12 citations
11. 11*

    Dark Kinetic Heating of Neutron Stars and An Infrared Window On WIMPs, SIMPs, and Pure Higgsinos

    Masha Baryakhtar🇨🇦 · Joseph Bramante🇨🇦 · Shirley Weishi Li🇺🇸 · Tim Linden🇺🇸 · Nirmal Raj🇺🇸

    We identify a largely model-independent signature of dark matter interactions with nucleons and electrons. Dark matter in the local galactic halo, gravitationally accelerated to over half the speed of light, scatters against and deposits kinetic energy into neutron stars, heating them to infrared blackbody temperatures. The resulting radiation could potentially be detected by the James Webb Space Telescope, the Thirty Meter Telescope, or the European Extremely Large Telescope. This mechanism also produces optical emission from neutron stars in the galactic bulge, and X-ray emission near the galactic center, because dark matter is denser in these regions. For GeV - PeV mass dark matter, dark kinetic heating would initially unmask any spin-independent or spin-dependent dark matter-nucleon cross-sections exceeding $2\times 10^{-45}$ cm${}^2$, with improved sensitivity after more telescope exposure. For lighter-than-GeV dark matter, cross-section sensitivity scales inversely with dark matter mass because of Pauli blocking; for heavier-than-PeV dark matter, it scales linearly with mass as a result of needing multiple scatters for capture. Future observations of dark sector-warmed neutron stars could determine whether dark matter annihilates in or only kinetically heats neutron stars. Because inelastic inter-state transitions of up to a few GeV would occur in relativistic scattering against nucleons, elusive inelastic dark matter like pure Higgsinos can also be discovered.

    hep-phastro-ph.GAastro-ph.HEastro-ph.IM+1PRL(2017)·227 citations
12. 12*

    The MSR Mass and the $\mathcal{O}({\Lambda }_{\mathrm{QCD}})$ Renormalon Sum Rule

    Andre H. Hoang🇦🇹 · Ambar Jain🇮🇳 · Christopher Lepenik🇦🇹 · Vicent Mateu🇪🇸 · Moritz Preisser🇦🇹 · Ignazio Scimemi🇪🇸 · Iain W. Stewart🇺🇸

    We provide a detailed description and analysis of a low-scale short-distance mass scheme, called the MSR mass, that is useful for high-precision top quark mass determinations, but can be applied for any heavy quark $Q$. In contrast to earlier low-scale short-distance mass schemes, the MSR scheme has a direct connection to the well known $\overline{\mathrm{MS}}$ mass commonly used for high-energy applications, and is determined by heavy quark on-shell self-energy Feynman diagrams. Indeed, the MSR mass scheme can be viewed as the simplest extension of the $\overline{\mathrm{MS}}$ mass concept to renormalization scales $\ll m_Q$. The MSR mass depends on a scale $R$ that can be chosen freely, and its renormalization group evolution has a linear dependence on $R$, which is known as R-evolution. Using R-evolution for the MSR mass we provide details of the derivation of an analytic expression for the normalization of the $\mathcal{O}({\Lambda }_{\mathrm{QCD}})$ renormalon asymptotic behavior of the pole mass in perturbation theory. This is referred to as the $\mathcal{O}({\Lambda }_{\mathrm{QCD}})$ renormalon sum rule, and can be applied to any perturbative series. The relations of the MSR mass scheme to other low-scale short-distance masses are analyzed as well.

    hep-phJHEP(2018)·105 citations
13. 13*

    Top-Quark Physics: Status and Prospects

    Ulrich Husemann🇩🇪

    After the discovery of the top quark more than 20 years ago, its properties have been studied in great detail both in production and in decay. Increasingly sophisticated experimental results from the Fermilab Tevatron and from Run 1 and Run 2 of the LHC at CERN are complemented by very precise theoretical predictions in the framework of the standard model of particle physics and beyond. In this article the current status of top-quark physics is reviewed, focusing on experimental results, and a perspective of top-quark physics at the LHC and at future colliders is given.

    ↳ hep-exhep-phPPNP(2017)·56 citations
14. 14*

    Quartic propagators, negative norms and the physical spectrum

    John F. Donoghue🇺🇸

    Many arguments against quartic propagators, negative norm states and related effects concern the sicknesses which occur when the spectrum of the free particle Hamiltonian is formed. However, if the theory is more complicated, for example involving confinement such that the particle in question does not appear in the physical spectrum, those considerations do not apply directly. Path integral methods suggest that some of these may be acceptable theories. I provide an example that should be able to be simulated on a lattice which then allows a non-perturbative resolution of this question. In its SU(2) version it involves a scalar triplet with a quartic derivative Lagrangian coupled to the SU(2) gauge field. If this is verified to be a healthy theory, it could open new avenues in model building. I also discuss how strong interactions can dynamically modify the dispersion relation leaving a healthy effective field theory, using conformal gravity coupled to a Yang-Mills theory as an example. Such a theory could possibly form a UV completion for quantum gravity.

    ↳ hep-thgr-qchep-phPRD(2017)·36 citations
15. 15*

    Critical magnetic fields in a superconductor coupled to a superfluid

    Alexander Haber🇦🇹 · Andreas Schmitt🇬🇧

    We study a superconductor that is coupled to a superfluid via density and derivative couplings. Starting from a Lagrangian for two complex scalar fields, we derive a temperature-dependent Ginzburg-Landau potential, which is then used to compute the phase diagram at nonzero temperature and external magnetic field. This includes the calculation of the critical magnetic fields for the transition to an array of magnetic flux tubes, based on an approximation for the interaction between the flux tubes. We find that the transition region between type-I and type-II superconductivity changes qualitatively due to the presence of the superfluid: the phase transitions at the upper and lower critical fields in the type-II regime become first order, opening the possibility of clustered flux tube phases. These flux tube clusters may be realized in the core of neutron stars, where superconducting protons are expected to be coupled to superfluid neutrons.

    ↳ hep-thastro-ph.HEcond-mat.supr-conhep-phPRD(2017)·39 citations
16. 16*

    An effective formalism for testing extensions to General Relativity with gravitational waves

    Solomon Endlich🇺🇸 · Victor Gorbenko🇺🇸 · Junwu Huang🇺🇸 · Leonardo Senatore🇺🇸

    The recent direct observation of gravitational waves (GW) from merging black holes opens up the possibility of exploring the theory of gravity in the strong regime at an unprecedented level. It is therefore interesting to explore which extensions to General Relativity (GR) could be detected. We construct an Effective Field Theory (EFT) satisfying the following requirements. It is testable with GW observations; it is consistent with other experiments, including short distance tests of GR; it agrees with widely accepted principles of physics, such as locality, causality and unitarity; and it does not involve new light degrees of freedom. The most general theory satisfying these requirements corresponds to adding to the GR Lagrangian operators constructed out of powers of the Riemann tensor, suppressed by a scale comparable to the curvature of the observed merging binaries. The presence of these operators modifies the gravitational potential between the compact objects, as well as their effective mass and current quadrupoles, ultimately correcting the waveform of the emitted GW.

    ↳ gr-qcastro-ph.COastro-ph.HEhep-ph+1JHEP(2017)·221 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.