Thu·Aug 9, 2018Thursday·August 9, 2018

1. 01*

   Neutrino Masses and Mixings Dynamically Generated by a Light Dark Sector

   Enrico Bertuzzo🇧🇷 · Sudip Jana🇺🇸 · Pedro A. N. Machado🇺🇸 · Renata Zukanovich Funchal🇧🇷

   Neutrinos may be the harbingers of new dark sectors, since the renormalizable neutrino portal allows for their interactions with hidden new physics. We propose here to use this fact to connect the generation of neutrino masses to a light dark sector, charged under a new $U(1{)}_{\mathcal{D}}$ dark gauge symmetry. We introduce the minimal number of dark fields to obtain an anomaly free theory with spontaneous breaking of the dark symmetry, and obtain automatically the inverse seesaw Lagrangian. In addition, the so-called $\mu$-term of the inverse seesaw is dynamically generated and technically natural in this framework. As a bonus, the new light dark gauge boson can provide a possible explanation to the MiniBooNE anomaly.

   hep-phPLB(2019)·100 citations
2. 02*

   Extracting many-body color charge correlators in the proton from exclusive DIS at large Bjorken x

   Adrian Dumitru🇺🇸 · Gerald A. Miller🇺🇸 · Raju Venugopalan🇺🇸

   We construct a general QCD light front formalism to compute many-body color charge correlators in the proton. These form factors can be extracted from deeply inelastic scattering measurements of exclusive final states in analogy to electromagnetic form factors extracted in elastic electron scattering experiments. Particularly noteworthy is the potential to extract a novel Odderon form factor, either indirectly from exclusive $J/\Psi$ measurements, or directly from exclusive measurements of the ${\eta }_c$ or tensor mesons at large Bjorken x. Besides the intrinsic information conveyed by these color charge correlators on the spatio-temporal tomography at the sub-femtoscopic scale at large x, the corresponding cumulants extend the domain of validity of McLerran-Venugopalan type weight functionals from small x and large nuclei to nucleons and light nuclei at large $x$, as well as to non-zero momentum transfer. This may significantly reduce nonperturbative systematic uncertainties in the initial conditions for QCD evolution equations at small $x$ and could be of strong relevance for the phenomenology of present and future collider experiments.

   hep-phnucl-thPRD(2018)·45 citations
3. 03*

   Particle decay in post inflationary cosmology

   Nathan Herring🇺🇸 · Brian Pardo🇺🇸 · Daniel Boyanovsky🇺🇸 · Andrew R. Zentner🇺🇸

   We study scalar particle decay during the radiation and matter dominated epochs of a standard cosmological model. An adiabatic approximation is introduced that is valid for degrees of freedom with typical wavelengths much smaller than the particle horizon ($\propto$~Hubble radius) at a given time. We implement a non-perturbative method that includes the cosmological expansion and obtain a cosmological Fermi's Golden Rule that enables one to compute the decay law of a parent particle of mass $m_1$, along with the build up of the population of daughter particles of mass $m_2$. The survival probability of the decaying particle is $P(t)=e^{-{\tilde{\Gamma }}_k(t)t}$ with ${\tilde{\Gamma }}_k(t)$ being an \emph{effective momentum and time dependent decay rate}. It features a transition time scale $t_{nr}$ between the relativistic and non-relativistic regimes and for $k\ne 0$ is always smaller than the analogous rate in Minkowski spacetime, as a consequence of (local) time dilation and the cosmological redshift. For $t\ll t_{nr}$ the decay law is a "stretched exponential" $P(t)=e^{-(t/t^{\ast }{)}^{3/2}}$, whereas for the non-relativistic stage with $t\gg t_{nr}$, we find $P(t)=e^{-{\Gamma }_{0}t}(t/t_{nr}{)}^{{\Gamma }_0{t}_{nr}/2}$. The Hubble time scale $\propto 1/H(t)$ introduces an energy uncertainty $\Delta E\sim H(t)$ which relaxes the constraints of kinematic thresholds. This opens new decay channels into heavier particles for $2\pi E_k(t)H(t)\gg 4m_2^2-m_1^2$, with $E_k(t)$ the (local) comoving energy of the decaying particle. As the expansion proceeds this channel closes and the usual two particle thresholds restrict the decay kinematics.

   hep-phastro-ph.COgr-qchep-thPRD(2018)·19 citations
4. 04*

   Indirect Detection of Sub-GeV Dark Matter Coupling to Quarks

   Jason Kumar🇺🇸

   We consider photon signals arising from the annihilation or decay of low-mass (sub-GeV) dark matter which couples dominantly to quarks. In this scenario, the branching fractions to the various kinematically accessible hadronic final states can largely be determined from chiral perturbation theory. Several of these final states yield striking spectral features in the sub-GeV photon spectrum. New experiments, such as e-ASTROGAM and AMEGO, are in development to improve sensitivity in this energy range, and we discuss their potential sensitivity to this class of models.

   hep-phastro-ph.COPRD(2018)·13 citations
5. 05*

   Muon conversion to electron in nuclei within the BLMSSM

   Tao Guo🇨🇳 · Shu-Min Zhao🇨🇳 · Xing-Xing Dong🇨🇳 · Chun-Gui Duan🇨🇳 · Tai-Fu Feng🇨🇳

   In a supersymmetric extension of the standard model with local gauged baryon and lepton numbers (BLMSSM), there are new sources for lepton flavor violation, because the right-handed neutrinos, new gauginos and Higgs are introduced. We investigate muon conversion to electron in nuclei within the BLMSSM in detail. The numerical results indicate that the $\mu \to e$ conversion rates in nuclei within the BLMSSM can reach the experimental upper bound, which may be detected in the future experiments.

   hep-phEPJC(2018)·4 citations
6. 06*

   Lorentz-violating scalar Hamiltonian and equivalence principle in a static metric

   Zhi Xiao🇨🇳

   In this paper, we obtain a nonrelativistic Hamiltonian from the Lorentz-violating (LV) scalar Lagrangian in the minimal SME. The Hamiltonian is obtained by two different methods. One is through the usual ansatz $\Phi (t,\vec{r})=e^{-imt}\Psi (t,\vec{r})$ applied to the LV corrected Klein-Gordon equation, and the other is the Foldy-Wouthuysen transformation. The consistency of our results is also partially supported by the comparison with the spin-independent part of the fermion Hamiltonian. In this comparison, we can also establish a relation between the set of scalar LV coefficients with their fermion counterparts. Using a pedagogical definition of the weak equivalence principle (WEP), we further point out that the LV Hamiltonian not only necessarily violates universal free fall, which is clearly demonstrated in the geodesic deviation, but also violates WEP in a semi-classical setting. As a bosonic complement, this method can be straightforwardly applicable to the spin-1 case, which shall be useful in the analysis of atomic tests of WEP, such as the case of the ${}^{87}{\text{Rb}}_1$ atom.

   hep-phPRD(2018)·8 citations
7. 07*

   Neutrino scattering and B anomalies from hidden sector portals

   Alakabha Datta🇺🇸 · Bhaskar Dutta🇺🇸 · Shu Liao🇺🇸 · Danny Marfatia🇺🇸 · Louis E. Strigari🇺🇸

   We examine current constraints on and the future sensitivity to the strength of couplings between quarks and neutrinos in the presence of a form factor generated from loop effects of hidden sector particles that interact with quarks via new interactions. We consider models associated with either vector or scalar interactions of quarks and leptons generated by hidden sector dynamics. We study constraints on these models using data from coherent elastic neutrino-nucleus scattering and solar neutrino experiments and demonstrate how these new interactions may be discovered by utilizing the recoil spectra. We show that our framework can be naturally extended to explain the lepton universality violating neutral current B decay anomalies, and that in a model framework the constraints from neutrino scattering can have implications for these anomalies.

   hep-phJHEP(2019)·27 citations
8. 08*

   Two Higgs Doublets and a Complex Singlet: Disentangling the Decay Topologies and Associated Phenomenology

   Sebastian Baum🇸🇪 · Nausheen R. Shah🇺🇸

   We present a systematic study of an extension of the Standard Model (SM) with two Higgs doublets and one complex singlet (2HDM+S). In order to gain analytical understanding of the parameter space, we re-parameterize the 27 parameters in the Lagrangian by quantities more closely related to physical observables: physical masses, mixing angles, trilinear and quadratic couplings, and vacuum expectation values. Embedding the 125\,GeV SM-like Higgs boson observed at the LHC places stringent constraints on the parameter space. In particular, the mixing of the SM-like interaction state with the remaining states is severely constrained, requiring approximate alignment without decoupling in the region of parameter space where the additional Higgs bosons are light enough to be accessible at the LHC. In contrast to 2HDM models, large branching ratios of the heavy Higgs bosons into two lighter Higgs bosons or a light Higgs and a $Z$ boson, so-called Higgs cascade decays, are ubiquitous in the 2HDM+S. Using currently available limits, future projections, and our own collider simulations, we show that combining different final states arising from Higgs cascades would allow to probe most of the interesting region of parameter space with Higgs boson masses up to 1\,TeV at the LHC with $L=3000{\mathrm{fb}}^{-1}$ of data.

   hep-phhep-exJHEP(2018)·64 citations
9. 09*

   Constraints on millicharged particles with low threshold germanium detectors at Kuo-Sheng Reactor Neutrino Laboratory

   TEXONO Collaboration: L. Singh🇹🇼 · J.W. Chen🇹🇼 · H.C. Chi🇹🇼 · C.-P. Liu🇹🇼 · M.K. Pandey🇹🇼 · H.T. Wong🇹🇼 · C.P. Wu🇹🇼 · M. Agartioglu🇹🇼 · M. Deniz🇹🇼 · H.B. Li🇹🇼 · S.T. Lin🇨🇳 · V. Sharma🇹🇼 and 3 other authors

   Relativistic millicharged particles (${\chi }_q$) have been proposed in various extensions to the Standard Model of particle physics. We consider the scenarios where they are produced at nuclear reactor core and via interactions of cosmic-rays with the earth's atmosphere. Millicharged particles could also be candidates for dark matter, and become relativistic through acceleration by supernova explosion shock waves. The atomic ionization cross section of ${\chi }_q$ with matter are derived with the equivalent photon approximation. Smoking-gun signatures with significant enhancement in the differential cross section are identified. New limits on the mass and charge of ${\chi }_q$ are derived, using data taken with a point-contact germanium detector with 500g mass functioning at an energy threshold of 300~eV at the Kuo-Sheng Reactor Neutrino Laboratory.

   hep-phhep-exPRD(2019)·68 citations
10. 10*

    Thermoelectric effect and Seebeck coefficient for hot and dense hadronic matter

    Jitesh R. Bhatt🇮🇳 · Arpan Das🇮🇳 · Hiranmaya Mishra🇮🇳

    We investigate the thermoelectric effect for baryon rich plasma produced in heavy ion collision experiments. We estimate the associated Seebeck coefficient for the hadronic matter. Using kinetic theory within relaxation time approximation we calculate the Seebeck coefficient of a hadronic medium with a temperature gradient. The calculation is performed for hadronic matter modeled by hadron resonance gas model with hadrons and resonance states up to a cutoff in the mass as 2.25 GeV. We argue that the thermoelectric current produced by such effect can produce magnetic field in heavy ion collision experiments.

    hep-phnucl-thPRD(2019)·30 citations
11. 11*

    Helicity amplitudes in $B\to D^{\ast }\bar{\nu }l$ decay

    L. R. Dai🇨🇳 · E. Oset🇪🇸

    We use a recent formalism of the weak hadronic reactions that maps the transition matrix elements at the quark level into hadronic matrix elements, evaluated with an elaborate angular momentum algebra that allows finally to write the weak matrix elements in terms of easy analytical formulas. In particular they appear explicitly for the different spin third components of the vector mesons involved. We extend the formalism to a general case, with the operator ${\gamma }^{\mu }-\alpha {\gamma }^{\mu }{\gamma }_5$, that can accommodate different models beyond the standard model and study in detail the $B\to D^{\ast }\bar{\nu }l$ reaction for the different helicities of the $D^{\ast }$. The results are shown for each amplitude in terms of the $\alpha$ parameter that is different for each model. We show that $\frac{d\Gamma }{d{M}_{\mathrm{inv}}^{(\nu l)}}$ is very different for the different components $M=\pm 1,0$ and in particular the magnitude $\frac{d\Gamma }{d{M}_{\mathrm{inv}}^{(\nu l)}}{|}_{M=-1}-\frac{d\Gamma }{d{M}_{\mathrm{inv}}^{(\nu l)}}{|}_{M=+1}$ is very sensitive to the $\alpha$ parameter, which suggest to use this magnitude to test different models beyond the standard model. We also compare our results with the standard model and find very similar results, and practically identical at the end point of $M_{\mathrm{inv}}^{(\nu l)}=m_B-m_{D^{\ast }}$.

    hep-phEPJC(2018)·8 citations
12. 12*

    Multimessenger Astronomy and New Neutrino Physics

    Kevin J. Kelly🇺🇸 · Pedro A. N. Machado🇺🇸

    We discuss how to constrain new physics in the neutrino sector using multimessenger astronomical observations by the IceCube experiment. The information from time and direction coincidence with an identifiable source is used to improve experimental limits by constraining the mean free path of neutrinos from these sources. Over the coming years, IceCube is expected to detect neutrinos from a variety of neutrino-producing sources, and has already identified the Blazar TXS 0506+056 as a neutrino-producing source. We explore specific phenomenological models: additional neutrino interactions, neutrinophilic dark matter, and lepton-number-charged axion dark matter. For each new physics scenario, we interpret the observation of neutrinos from TXS 0506+056 as a constraint on the parameters of the new physics models. We also discuss mergers involving neutron stars and black holes, and how the detection of neutrinos coincident with these events could place bounds on the new physics models.

    hep-phastro-ph.HEJCAP(2018)·73 citations
13. 13*

    Effects of anomalous triple-gauge-boson interactions in diboson production with RECOLA2

    Mauro Chiesa🇩🇪 · Ansgar Denner🇩🇪 · Jean-Nicolas Lang🇨🇭

    Diboson production processes are of great importance in high-energy physics and a precise theoretical knowledge of VV production is mandatory not only in view of precision tests of the Standard Model but also in the one of new physics searches. We present results of arXiv:1804.01477, where we computed the NLO QCD and NLO electroweak corrections to diboson production processes at the LHC including the effect of the anomalous triple-gauge-boson interactions at NLO QCD accuracy. The anomalous triple-gauge-boson interactions are parametrized in terms of higher-dimensional operators in the effective field theory framework. Our calculation is the first application of Recola2 to effective field theory models.

    hep-phPoS(2018)·3 citations
14. 14*

    Predictions for the sky-averaged depth of the 21cm absorption signal at high redshift in cosmologies with and without non-baryonic cold dark matter

    Stacy McGaugh🇺🇸

    We consider the 21cm absorption signal expected at high redshift in cosmologies with and without non-baryonic cold dark matter. The expansion of the early universe decelerates strongly with dark matter, but approximately coasts without it. This results in a different path length across the epochs when absorption is expected, with the consequence that the absorption is predicted to be a factor of $\sim 2$ greater without dark matter than with it. Observation of such a signal would motivate consideration of extended theories of gravity in lieu of dark matter.

    ↳ astro-ph.COhep-phPRL(2018)·11 citations
15. 15*

    A Challenge to Lepton Universality in B Meson Decays

    Vera Lüth🇺🇸

    One of the key assumptions of the Standard Model of fundamental particles is that the interactions of the charged leptons, namely electrons, muons, and taus, differ only because of their different masses. While precision tests have not revealed any definite violation of this assumption, recent studies of B meson decays involving the higher-mass tau lepton have resulted in observations that challenge lepton universality at the level of four standard deviations. A confirmation of these results would point to new particles or interactions, and could have profound implications for our understanding of particle physics.

    ↳ hep-exhep-phHyperfine Interact.(2018)·0 citations
16. 16*

    Constraining Non-thermal Dark Matter by CMB

    Rouzbeh Allahverdi🇺🇸 · Koushik Dutta🇮🇳 · Anshuman Maharana🇮🇳

    A period of early matter domination can give rise to the correct dark matter abundance for a broad range of dark matter annihilation rate $⟨{\sigma }_{\mathrm{ann}}v{⟩}_{\mathrm{f}}$. Here, we examine this scenario for situations where $⟨{\sigma }_{\mathrm{ann}}v{⟩}_{\mathrm{f}}$ is below the nominal value for thermal dark matter $3\times 10^{-26}$ cm${}^3$ s${}^{-1}$ as possibly indicated by some recent experiments. We show that obtaining the correct relic abundance sets a lower bound on the duration of early matter domination era in this case. On the other hand, provided that the post-inflationary universe has an equation of state characterized by $w\le 1/3$, the requirement that the scalar spectral index $n_s$ be within the observationally allowed range limits the duration of this epoch from above. By combining these considerations, we show that the current and future cosmic microwave background experiments can tightly constrain the parameter space for this scenario. In particular, models of inflation with a tensor-to-scalar ratio below $\mathcal{O}(0.01)$ may disfavor non-thermal supersymmetric dark matter from a modulus-driven early matter domination epoch.

    ↳ astro-ph.COgr-qchep-phhep-thJCAP(2018)·26 citations
17. 17*

    Rich structure of non-thermal relativistic CMB spectral distortions from high energy particle cascades at redshifts $z\lesssim 2\times 10^5$

    Sandeep Kumar Acharya🇮🇳 · Rishi Khatri🇮🇳

    It is generally assumed that for energy injection before recombination, all of the injected energy is dissipated as heat in the baryon-photon plasma, giving rise to the $y$-type, $i$-type, and $\mu$-type distortions in the CMB spectrum. We show that this assumption is incorrect when the energy is injected in the form of energetic (i.e. energy much greater than the background CMB temperature) particles. We evolve the electromagnetic cascades, from the injection of high energy particles, in the expanding Universe and follow the non-thermal component of CMB spectral distortions resulting from the interaction of the electromagnetic shower with the background photons, electrons, and ions. The electromagnetic shower loses a substantial fraction of its energy to the CMB spectral distortions before the energy of the particles in the shower has degraded to low enough energies that they can thermalize with the background plasma. This spectral distortion is the result of the interaction of non-thermal energetic electrons in the shower with the CMB and thus has a shape that is substantially different from the $y$-type or $i$-type distortions. The shape of the final \emph{non-thermal relativistic} ($ntr$-type) CMB spectral distortion depends upon the initial energy spectrum of the injected electrons, positrons, and photons and thus has information about the energy injection mechanism e.g. the decay or annihilation channel of the decaying or annihilating dark matter particles. The shape of the spectral distortion is also sensitive to the redshift of energy injection. Our calculations open up a new window into the energy injection at $z\lesssim 2\times 10^5$ which is not degenerate with, and can be distinguished from the low redshift thermal $y$-type distortions.

    ↳ astro-ph.COastro-ph.HEhep-phPRD(2019)·38 citations
18. 18*

    Time evolution of the X-ray and gamma-ray fluxes of the Crab pulsar

    L. L. Yan🇨🇳 · M. Y. Ge🇨🇳 · F. J. Lu🇨🇳 · S. J. Zheng🇨🇳 · Y. L. Tuo🇨🇳 · Z. J. Li🇨🇳 · L. M. Song🇨🇳 · J. L. Qu🇨🇳

    We studied the evolution of the X-ray and gamma-ray spectra of the Crab pulsar utilizing the 11-year observations from the Rossi X-ray Timing Explorer (RXTE) and 9-year observations from the Fermi Gamma-ray Space Telescope (FGST). By fitting the spectrum of each observation, we obtained the corresponding flux, and then analysed the long term evolution of the X-ray (or gamma-ray) luminosities as well as their correlations with the spin down power of the pulsar. The X-ray flux in 5-60 keV obtained by the Proportional Counter Array (PCA) of RXTE decreases with a rate of (-2.4+/-0.4)*10^(-14) erg cm^(-2) s^(-1) per day. The X-ray flux in 15-250 keV obtained by the High Energy X-ray Timing Experiment (HEXTE) of RXTE and the gamma-ray flux in 0.1-300 GeV by the Large Area Telescope (LAT) onboard FGST show similar decreasing trend, but are unsignificant statistically. The 5--60 keV X-ray luminosity L_(X) is correlated with the spin down power L_(sd) by L_(X) propto L_(sd)^(1.6+/-0.3), which is similar to the statistical results for young pulsars.

    ↳ astro-ph.HEhep-phApJ(2018)·9 citations
19. 19*

    Electromagnetic Emission from newly-born Magnetar Spin-Down by Gravitational-Wave and Magnetic Dipole Radiations

    Hou-Jun Lü🇨🇳 · Le Zou🇨🇳 · Lin Lan🇨🇳 · En-Wei Liang🇨🇳

    A newly-born magnetar is thought to be central engine of some long gamma-ray bursts (GRBs). We investigate the evolution of the electromagnetic (EM) emission from the magnetic dipole (MD) radiation wind injected by spin-down of a newly-born magnetar via both quadrupole gravitational-wave (GW) and MD radiations. We show that the EM luminosity evolves as $L_{\mathrm{em}}\propto (1+t/{\tau }_c{)}^{\alpha }$, and $\alpha$ is $-1$ and $-2$ in the GW and MD radiation dominated scenarios, respectively. Transition from the GW to MD radiation dominated epoch may show up as a smooth break with slope changing from $-1$ to $-2$. If the magnetar collapses to a black hole before ${\tau }_c$, the MD radiation should be shut down, then the EM light curve should be a plateau followed by a sharp drop. The expected generic light curve in this paradigm is consistent with the canonical X-ray light curve of {\em Swift} long GRBs. The X-ray emission of several long GRBs are identified and interpreted as magnetar spin-down via GW or MD, as well as constrain the physical parameters of magnetar. The combination of MD emission and GRB afterglows may make the diversity of the observed X-ray light curves. This may interpret the observed chromatic behaviors of the X-ray and optical afterglow light curves and the extremely low detection rate of a jet-like break in the X-ray afterglow light curves of long GRBs.

    ↳ astro-ph.HEhep-phMNRAS(2018)·46 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.