Fri·Mar 22, 2019Friday·March 22, 2019

1. 01*

   Resummed photon spectrum from dark matter annihilation for intermediate and narrow energy resolution

   M. Beneke🇩🇪 · A. Broggio🇮🇹 · C. Hasner🇩🇪 · K. Urban🇩🇪 · M. Vollmann🇩🇪

   The annihilation cross section of weakly interacting TeV scale dark matter particles ${\chi }^0$ into photons is affected by large quantum corrections due to electroweak Sudakov logarithms and the Sommerfeld effect. We extend our previous work on the resummation of the semi-inclusive photon energy spectrum in ${\chi }^0{\chi }^0\to \gamma +X$ in the vicinity of the maximal photon energy $E_{\gamma }=m_{\chi }$ with NLL' accuracy from the case of narrow photon energy resolution $E_{\mathrm{res}}^{\gamma }$ of order $m_W^2/m_{\chi }$ to intermediate resolution of order $E_{\mathrm{res}}^{\gamma }\sim m_W$. We also provide details on the previous narrow resolution calculation. The two calculations, performed in different effective field theory set-ups for the wino dark matter model, are then shown to match well, providing an accurate representation up to energy resolutions of about 300 GeV.

   hep-phJHEP(2019)·41 citations
2. 02*

   Reconciling dark matter, $R_{K^{(\ast )}}$ anomalies and $(g-2{)}_{\mu }$ in an $L_{\mu }-L_{\tau }$ scenario

   Anirban Biswas🇮🇳 · Avirup Shaw🇮🇳

   We propose an anomaly free unified scenario by invocation of an extra local ${\mathrm{U}(1)}_{L_{\mu }-L_{\tau }}$ gauge symmetry. This scenario simultaneously resolves the $R_{K^{(\ast )}}$ anomalies, the dark matter puzzle and the long-standing discrepancy in muon's anomalous magnetic moment. A complex scalar ($\eta$) having nonzero $L_{\mu }-L_{\tau }$ charge has been introduced to break this new U(1) symmetry spontaneously. Moreover, for the purpose of studying dark matter phenomenology and $R_{K^{(\ast )}}$ anomalies in a correlated manner, we introduce an inert ${\mathrm{SU}(2)}_L$ scalar doublet ($\Phi$), a ${\mathbb{Z}}_2$-odd real singlet scalar ($S$) and a ${\mathbb{Z}}_2$-odd coloured fermion ($\chi$) which transforms vectorially under the ${\mathrm{U}(1)}_{L_{\mu }-L_{\tau }}$ symmetry. This extra gauge symmetry provides a new gauge boson $Z_{\mu \tau }$ which not only gives additional contribution to both $b\to s\ell \ell$ transition and $(g-2{)}_{\mu }$ but also provides a crucial annihilation channel for dark matter candidate ${\rho }_1$ of the present scenario. This ${\rho }_1$ is an admixture of CP-even neutral component of $\Phi$ and $S$. Our analysis shows that the low mass dark matter regime ($M_{{\rho }_1}\lesssim 60$ GeV) is still allowed by the experiments like XENON1T, LHC (via Higgs invisible branching) and Fermi-LAT, making the dark matter phenomenology drastically different from the standard Inert Doublet and the Scalar Singlet models. Furthermore, the present model is also fairly consistent with the observed branching ratio of $B\to X_s\gamma$ in $3\sigma$ range and is quite capable of explaining neutrino masses and mixings via Type-I seesaw mechanism if we add three right handed neutrinos in the particle spectrum. Finally, we use the latest ATLAS data of non-observation of a resonant ${\ell }^{+}{\ell }^{-}$ signal at the 13 TeV LHC to constrain the mass-coupling plane of $Z_{\mu \tau }$.

   hep-phJHEP(2019)·43 citations
3. 03*

   Nucleon Femtography from Exclusive Reactions

   Simonetta Liuti🇺🇸

   Major breakthroughs over the last two decades have led us to access information on how the nucleon's mass, spin and mechanical properties are generated from its quark and gluon degrees of freedom. On one side, a theoretical framework has been developed which enables the extraction of 3D parton distributions from deeply virtual exclusive scattering experiments. On the other hand, the so called gravitomagnetic form factors parameterizing the QCD energy momentum tensor of the nucleon have been connected to the Mellin moments of the 3D parton distributions. Current efforts in both experiment and theory are being directed at using information from electron scattering experiments to map out and eventually visualize these 3D distributions as well as the mass, spin and mechanical properties of the nucleon and of spin 0, 1/2, and 1 nuclei. A new science of nucleon femtography is emerging where the 3D structure of the nucleon will be studied merging information from current and forthcoming data from various facilities including the future EIC and the new influx of data science, imaging, and visualization.

   hep-phPoS(2019)·1 citation
4. 04*

   Exploring New Physics from nu_tau events in OPERA

   Davide Meloni🇮🇹

   We analyze in details the impact of the $10$ ${\nu }_{\tau }$ events seen in the OPERA experiment in constraining the Non Standard Interaction parameter ${\epsilon }_{\mu \tau }$ affecting neutrino propagation in matter and the allowed parameter space of models with one sterile neutrino of the $3+1$ type.

   hep-phPLB(2019)·7 citations
5. 05*

   A Model of Neutrino Anomalies and IceCube data

   Y. H. Ahn🇰🇷 · Sin Kyu Kang🇰🇷

   We interpret the neutrino anomalies in neutrino oscillation experiments and the high energy neutrino events at IceCube in terms of neutrino oscillations in an extension of the standard model where three sterile neutrinos are introduced so as to make two light neutrinos to be Pseudo-Dirac particles and a light neutrino to be a Majorana particle. Our model is different from the so-called $3+n$ model with $n$ sterile neutrinos suggested to interpret short baseline anomalies in terms of neutrino oscillations. While the Pontecorvo-Maki-Nakagawa-Sakata (PMNS) matrix in $3+n$ model is simply extended to $n\times n$ unitary matrix, the neutrino mixing matrix in our model is parameterized so as to keep the $3\times 3$ PMNS mixing matrix for three active neutrinos unitary. There are also no flavor changing neutral current interactions leading to the conversion of active neutrinos to sterile ones or vice versa. We derive new forms of neutrino oscillation probabilities containing the new interference between the active and sterile neutrinos which are characterized by additional new parameters $\Delta m^2$ and $\theta$. Based on the new formulae derived, we show how the short baseline neutrino anomalies can be explained in terms of oscillations, and study the implication of the high energy neutrino events detected at IceCube on the probe of pseudo-Dirac neutrinos. New phenomenological effects attributed to the existence of the sterile neutrinos are discussed.

   hep-phJHEP(2019)·4 citations
6. 06*

   On the Gravitational Force on Anti-Matter

   Allen Caldwell🇩🇪 · Gia Dvali🇩🇪

   A number of experiments are currently underway on antimatter, particularly anti-hydrogen, to test whether the fundamental interactions behave the same way as for matter. Here we present a simple argument showing that a bound on a difference in gravitational forces exerted on matter and antimatter is already so severe that is goes well beyond the sensitivity of the above measurements.

   hep-phgr-qchep-exhep-thFortsch.Phys.(2021)·3 citations
7. 07*

   Relativistic fluid dynamics and its extensions as an effective field theory

   David Montenegro🇧🇷 · Radoslaw Ryblewski🇵🇱 · Giorgio Torrieri🇧🇷

   We examine hydrodynamics from the perspective of an effective field theory. The microscopic scale in this case is the thermalization scale, and the macroscopic scale is the gradient, with thermal fluctuations playing the role of $\hslash$. We argue that this method can be applied both, to consistently include thermal fluctuations in the theory, and to extend hydrodynamics to systems whose microscopic structure is non-trivial. For the latter, we discuss the case of spin polarization and gauge theories.

   ↳ hep-thhep-phphysics.flu-dynActa Phys.Polon.B(2019)·13 citations
8. 08*

   Gravitational Production of Superheavy Dark Matter and Associated Cosmological Signatures

   Lingfeng Li🇨🇳 · Tomohiro Nakama🇨🇳 · Chon Man Sou🇨🇳 · Yi Wang🇨🇳 · Siyi Zhou🇨🇳

   We study the gravitational production of super-Hubble-mass dark matter in the very early universe. We first review the simplest scenario where dark matter is produced mainly during slow roll inflation. Then we move on to consider the cases where dark matter is produced during the transition period between inflation and the subsequent cosmological evolution. The limits of smooth and sudden transitions are studied, respectively. The relic abundances and the cosmological collider signals are calculated.

   ↳ astro-ph.COhep-phhep-thJHEP(2019)·101 citations
9. 09*

   Exploring neutrino mass and mass hierarchy in interacting dark energy models

   Lu Feng🇨🇳 · Hai-Li Li🇨🇳 · Jing-Fei Zhang🇨🇳 · Xin Zhang🇨🇳

   We investigate how the dark energy properties impact the constraints on the total neutrino mass in interacting dark energy (IDE) models. In this study, we focus on two typical interacting dynamical dark energy models, i.e., the interacting $w$ cold dark matter (I$w$CDM) model and the interacting holographic dark energy (IHDE) model. To avoid the large-scale instability problem in IDE models, we apply the parameterized post-Friedmann approach to calculate the perturbation of dark energy. We employ the Planck 2015 cosmic microwave background temperature and polarization data, combined with low-redshift measurements on baryon acoustic oscillation distance scales, type Ia supernovae, and the Hubble constant, to constrain the cosmological parameters. We find that the dark energy properties could influence the constraint limits on the total neutrino mass. Once dynamical dark energy is considered in the IDE models, the upper bounds of $\sum m_{\nu }$ will be changed. By considering the values of ${\chi }_{\min }^2$, we find that in these IDE models the normal hierarchy case is slightly preferred over the inverted hierarchy case; for example, $\Delta {\chi }^2=2.720$ is given in the IHDE+$\sum m_{\nu }$ model. In addition, we also find that in the I$w$CDM+$\sum m_{\nu }$ model $\beta =0$ is consistent with current observational data inside the 1$\sigma$ range, and in the IHDE+$\sum m_{\nu }$ model $\beta >0$ is favored at more than 2$\sigma$ level.

   ↳ astro-ph.COgr-qchep-phSCPMA(2020)·47 citations
10. 10*

    A Strong Scalar Weak Gravity Conjecture and Some Implications

    Eduardo Gonzalo🇪🇸 · Luis E. Ibáñez🇪🇸

    We propose a new version of the scalar Weak Gravity Conjecture (WGC) which would apply to any scalar field coupled to quantum gravity. For a single scalar it is given by the differential constraint $V^{\prime \prime }\le (2V^{\prime \prime \prime 2}/V^{\prime \prime }-V^{\prime \prime \prime \prime })M_{\text{p}}^2$. It corresponds to the statement that self-interactions of a scalar must be stronger than gravity for any value of the scalar field. We find that the solutions which saturate the bound correspond to towers of extremal states with mass $m^2(\varphi )=m_0^2/((R/m{)}^2+1/(nR{)}^2)$, with $R^2=e^{\varphi }$, consistent with the emergence of an extra dimension at large or small $R$ and the existence of extended objects (strings). These states act as WGC states for the scalar $\varphi$. It is also consistent with the distance swampland conjecture with a built-in duality symmetry. From this constraint one can derive several swampland conjectures. In particular one finds that an axion potential is only consistent if $f\le M_{\text{p}}$. The conjecture has far reaching consequences and applies to several interesting physical systems: i) Among chaotic inflation potentials only those asymptotically linear may survive. ii) If applied to the radion of the circle compactification of the Standard Model to 3D, the constraint implies that the 4D cosmological constant scale must be larger than the mass of the lightest neutrino, which must be Dirac and in normal hierarchy. iii) It also constraints simplest moduli fixing string models. The simplest KKLT model is compatible with the constraints but the latter may be relevant for some choices of parameters.

    ↳ hep-thhep-phJHEP(2019)·87 citations
11. 11*

    Searching for the Evidence of Dynamical Dark Energy

    Deng Wang🇨🇳 · Wei Zhang🇨🇳 · Xin-He Meng🇨🇳

    In the statistical framework of model-independent Gaussian processes (GP), we search for the evidence of dynamical dark energy (DDE) using the "Joint Light-curve Analysis" (JLA) Type Ia supernovae (SNe Ia) sample, the 30 latest cosmic chronometer data points (H(z)), Planck's shift parameter from cosmic microwave background (CMB) anisotropies, the 156 latest HII galaxy measurements and 79 calibrated gamma-ray bursts (GRBs). We find that the joint constraint from JLA + H(z) + CMB + HII + GRB supports the global measurement of $H_0$ by Planck collaboration very much in the low redshift range $z\in [0,0.76]$ at the $2\sigma$ confidence level (C.L.), gives a cosmological constant crossing (quintom-like) equation of state (EoS) of DE at the $2\sigma$ C.L. and implies that the evolution of the late-time Universe may be actually dominated by the DDE.

    ↳ astro-ph.COgr-qchep-phEPJC(2019)·29 citations
12. 12*

    Time reversal invariance violation in neutron-nucleus scattering

    Pavel Fadeev🇩🇪 · Victor V. Flambaum🇦🇺

    Planning and interpretation of the experiments searching for the time reversal (T) and parity (P) violation in neutron reactions require values of the matrix elements of the T,P-violating nuclear forces between nuclear compound states. We calculate the root mean square values and the ratio of the matrix elements of the T,P-violating and P-violating interactions using statistical theory based on the properties of chaotic compound states and present the results in terms of the fundamental parameters in four different forms: in terms of the constants of the contact nuclear interaction, meson exchange constants, QCD theta-term and quark chromo-EDMs. Using current limits on these parameters, we obtain the upper bounds on the ratio of the matrix elements.

    ↳ nucl-thhep-phnucl-exphysics.atom-phPRC(2019)·24 citations
13. 13*

    New Neutron Star Equation of State with Quark-Hadron Crossover

    Gordon Baym🇺🇸 · Shun Furusawa🇯🇵 · Tetsuo Hatsuda🇯🇵 · Toru Kojo🇨🇳 · Hajime Togashi🇯🇵

    We present a much improved equation of state for neutron star matter, QHC19, with a smooth crossover from the hadronic regime at lower densities to the quark regime at higher densities. We now use the Togashi et al.~equation of state (Togashi:2017), a generalization of the Akmal-Pandharipande-Ravenhall equation of state of uniform nuclear matter, in the entire hadronic regime; the Togashi equation of state consistently describes non-uniform as well as uniform matter, and matter at beta equilibrium without the need for an interpolation between pure neutron and symmetric nuclear matter. We describe the quark matter regime at higher densities with the Nambu--Jona--Lasinio model, now identifying tight constraints on the phenomenological universal vector repulsion between quarks and the pairing interaction between quarks arising from the requirements of thermodynamic stability and causal propagation of sound. The resultant neutron star properties agree very well with the inferences of the LIGO/Virgo collaboration, from GW170817, of the pressure vs. baryon density, neutron star radii, and tidal deformabilities. The maximum neutron star mass allowed by QHC19 is 2.35 $M_{\odot }$, consistent with all neutron star mass determinations.

    ↳ astro-ph.HEhep-phnucl-thApJ(2019)·220 citations
14. 14*

    Analytic expressions for the second-order scalar perturbations in the $\Lambda$CDM Universe within the cosmic screening approach

    Maxim Eingorn🇺🇸 · N. Duygu Guran🇹🇷 · Alexander Zhuk🇹🇷

    We study the second-order scalar perturbations in the conventional $\Lambda$CDM Universe within the cosmic screening approach. The analytic expressions for both the velocity-independent and velocity-dependent second-order scalar perturbations are derived. We demonstrate how the Yukawa screening effect, which is inherent in the first-order metric corrections, manifests itself in the second-order ones. It is shown that the obtained formulas for the second-order perturbations are reduced to the known post-Newtonian expressions at distances much smaller than the Yukawa screening length. In the era of precision cosmology, these analytic formulas play an important role since the second-order metric corrections may affect the interpretation of observational data (e.g., the luminosity-redshift relation, gravitational lensing, baryon acoustic oscillations).

    ↳ gr-qcastro-ph.COhep-phhep-thPhys.Dark Univ.(2019)·8 citations
15. 15*

    Safe Glueballs and Baryons

    Thomas A. Ryttov🇩🇰 · Kimmo Tuominen🇫🇮

    We consider a non-Abelian gauge theory with $N_f$ fermions and discuss the possible existence of a non-trivial UV fixed point at large $N_f$. Specifically, we study the anomalous dimension of the (rescaled) glueball operator $\text{Tr}{F}^2$ to first order in $1/N_f$ by relating it to the derivative of the beta function at the fixed point. At the fixed point the anomalous dimension violates its unitarity bound and so the (rescaled) glueball operator is either decoupled or the fixed point does not exist. We also study the anomalous dimensions of the two spin-$1/2$ baryon operators to first order in $1/N_f$ for an $SU(3)$ gauge theory with fundamental fermions and find them to be relatively small and well within their associated unitarity bounds.

    ↳ hep-thhep-lathep-phJHEP(2019)·16 citations
16. 16*

    Evidence for quark-matter cores in massive neutron stars

    Eemeli Annala🇫🇮 · Tyler Gorda🇺🇸 · Aleksi Kurkela🇨🇭 · Joonas Nättilä🇸🇪 · Aleksi Vuorinen🇫🇮

    The theory governing the strong nuclear force, Quantum Chromodynamics, predicts that at sufficiently high energy densities hadronic nuclear matter undergoes a deconfinement transition to a new phase of quarks and gluons. Although this has been observed in ultrarelativistic heavy-ion collisions, it is currently an open question whether quark matter exists inside neutron stars. By combining astrophysical observations and theoretical ab-initio calculations in a model-independent way, we find that the inferred properties of matter in the cores of neutron stars with mass corresponding to 1.4 solar masses are compatible with nuclear model calculations. However, the matter in the interior of maximally massive, stable neutron stars exhibits characteristics of the deconfined phase, which we interpret as evidence for the presence of quark-matter cores. For the heaviest reliably observed neutron stars with masses of about two solar masses, the presence of quark matter is found to be linked to the behaviour of the speed of sound c_s in strongly interacting matter. If the conformal bound (c_s)^2 < 1/3 is not strongly violated, massive neutron stars are predicted to have sizable quark-matter cores. This finding has important implications for the phenomenology of neutron stars, and affects the dynamics of neutron star mergers with at least one sufficiently massive participant.

    ↳ astro-ph.HEhep-phnucl-thNat.Phys.(2020)·814 citations
17. 17*

    Direct millicharged dark matter cannot explain EDGES

    Cyril Creque-Sarbinowski🇺🇸 · Lingyuan Ji🇺🇸 · Ely D. Kovetz🇺🇸 · Marc Kamionkowski🇺🇸

    Heat transfer between baryons and millicharged dark matter has been invoked as a possible explanation for the anomalous 21-cm absorption signal seen by EDGES. Prior work has shown that the solution requires that millicharged particles make up only a fraction $(m_{\chi }/\mathrm{MeV})0.0115\%\lesssim f\lesssim 0.4\%$ of the dark matter and that their mass $m_{\chi }$ and charge $q_{\chi }$ have values $0.1\lesssim (m_{\chi }/\mathrm{MeV})\lesssim 10$ and $10^{-6}\lesssim (q_{\chi }/e)\lesssim 10^{-4}$. Here we show that such particles come into chemical equilibrium before recombination, and so are subject to a constraint on the effective number $N_{\mathrm{eff}}$ of relativistic degrees of freedom, which we update using Planck 2018 data. We moreover determine the precise relic abundance $f$ that results for a given mass $m_{\chi }$ and charge $q_{\chi }$ and incorporate this abundance into the constraints on the millicharged-dark-matter solution to EDGES. With these two results, the solution is ruled out if the relic abundance is set by freeze-out.

    ↳ astro-ph.COhep-phPRD(2019)·64 citations
18. 18*

    Entropy Bounds on Effective Field Theory from Rotating Dyonic Black Holes

    Clifford Cheung🇺🇸 · Junyu Liu🇺🇸 · Grant N. Remmen🇺🇸

    We derive new bounds on higher-dimension operator coefficients in four-dimensional Einstein-Maxwell theory. Positivity of classically-generated corrections to the Wald entropy of thermodynamically stable, rotating dyonic black holes implies a multiparameter family of field basis invariant inequalities that exhibit electromagnetic duality and are satisfied by examples from field and string theory. These bounds imply that effective operators modify the extremality condition of large black holes so as to permit their decay to smaller ones, thus satisfying the weak gravity conjecture.

    ↳ hep-thgr-qchep-phPRD(2019)·85 citations
19. 19*

    Optical analog of particle production in gravitational fields

    Igor I. Smolyaninov🇺🇸

    Strong enough electric field is predicted to spontaneously create electron-positron pairs in vacuum via Schwinger effect. A somewhat similar effect is predicted to occur in sufficiently strong inhomogeneous gravitational fields. However, due to necessity of very large field strength, these effects were never observed in the experiment. Here we demonstrate that optical analogs of very strong gravitational fields (up to ~10^24 g) and very strong gravitational field gradients (up to ~10^31 s-2) may be created in electromagnetic metamaterial waveguides, leading to an optical analog of particle production in gravitational fields. Such waveguide geometries may also potentially be used to search for axion-like particles weakly interacting with electromagnetic field.

    ↳ physics.opticsgr-qchep-phEPL(2019)·2 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.