Tue·May 9, 2017Tuesday·May 9, 2017

1. 01*

   Dark Matter Self-interactions and Small Scale Structure

   Sean Tulin🇨🇦 · Hai-Bo Yu🇺🇸

   We review theories of dark matter (DM) beyond the collisionless paradigm, known as self-interacting dark matter (SIDM), and their observable implications for astrophysical structure in the Universe. Self-interactions are motivated, in part, due to the potential to explain long-standing (and more recent) small scale structure observations that are in tension with collisionless cold DM (CDM) predictions. Simple particle physics models for SIDM can provide a universal explanation for these observations across a wide range of mass scales spanning dwarf galaxies, low and high surface brightness spiral galaxies, and clusters of galaxies. At the same time, SIDM leaves intact the success of $\Lambda$CDM cosmology on large scales. This report covers the following topics: (1) small scale structure issues, including the core-cusp problem, the diversity problem for rotation curves, the missing satellites problem, and the too-big-to-fail problem, as well as recent progress in hydrodynamical simulations of galaxy formation; (2) N-body simulations for SIDM, including implications for density profiles, halo shapes, substructure, and the interplay between baryons and self-interactions; (3) semi-analytic Jeans-based methods that provide a complementary approach for connecting particle models with observations; (4) merging systems, such as cluster mergers (e.g., the Bullet Cluster) and minor infalls, along with recent simulation results for mergers; (5) particle physics models, including light mediator models and composite DM models; and (6) complementary probes for SIDM, including indirect and direct detection experiments, particle collider searches, and cosmological observations. We provide a summary and critical look for all current constraints on DM self-interactions and an outline for future directions.

   hep-phastro-ph.COastro-ph.GAPhys.Rept.(2018)·1373 citations
2. 02*

   Model-independent constraints on hadronic form factors with above-threshold poles

   Irinel Caprini🇷🇴 · Benjamin Grinstein🇺🇸 · Richard F. Lebed🇺🇸

   Model-independent constraints on hadronic form factors, in particular those describing exclusive semileptonic decays, can be derived from the knowledge of field correlators calculated in perturbative QCD, using analyticity and unitarity. The location of poles corresponding to below-threshold resonances, i.e., stable states that cannot decay into a pair of hadrons from the crossed channel of the form factor, must be known a priori, and their effect, accounted for through the use of Blaschke factors, is to reduce the strength of the constraints in the semileptonic region. By contrast, above-threshold resonances appear as poles on unphysical Riemann sheets, and their presence does not affect the original model-independent constraints. We discuss the possibility that the above-threshold poles can provide indirect information on the form factors on the first Riemann sheet, either through information from their residues or by constraining the discontinuity function. The bounds on form factors can be improved by imposing, in an exact way, the additional information in the extremal problem. The semileptonic $K\to \pi \ell \nu$ and $D\to \pi \ell \nu$ decays are considered as illustrations.

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

   Implications of the Principle of Maximum Conformality for the QCD Strong Coupling

   Alexandre Deur🇺🇸 · Jian-Ming Shen🇨🇳 · Xing-Gang Wu🇨🇳 · Stanley J. Brodsky🇺🇸 · Guy F. de Teramond🇨🇷

   The Principle of Maximum Conformality (PMC) provides scale-fixed perturbative QCD predictions which are independent of the choice of the renormalization scheme, as well as the choice of the initial renormalization scale. In this article, we will test the PMC by comparing its predictions for the strong coupling \alpha^s_{g_1}(Q), defined from the Bjorken sum rule, with predictions using conventional pQCD scale-setting. The two results are found to be compatible with each other and with the available experimental data. However, the PMC provides a significantly more precise determination, although its domain of applicability (Q \gtrsim 1.5 GeV) does not extend to as small values of momentum transfer as that of a conventional pQCD analysis (Q \gtrsim 1 GeV). We suggest that the PMC range of applicability could be improved by a modified intermediate scheme choice or using a single effective PMC scale.

   hep-phPLB(2017)·35 citations
4. 04*

   $B\to D^{(\ast )}\tau {\nu }_{\tau }$ in the 2HDM with an anomalous $\tau$ coupling

   Jong-Phil Lee🇰🇷

   The puzzle of $R(D^{(\ast )})$ associated with $B\to D^{(\ast )}\tau \nu$ decay is addressed in the two-HIggs-doublet model. An anomalous coupling of $\tau$ to the charged Higgs is introduced to fit the data from BaBar, Belle, and LHCb. It is shown that all of the four types of the model yield similar values of the minimum ${\chi }^2$. Also shown is that the newly normalized $R(D^{(\ast )})$ with the branching ratio of $B\to \tau \nu$ decay exhibits much smaller minimum ${\chi }^2$.

   hep-phPRD(2017)·25 citations
5. 05*

   Detecting Dark Photon with Reactor Neutrino Experiments

   HyangKyu Park🇰🇷

   We propose to search for light $U(1)$ dark photons, $A^{\prime }$, produced via kinetically mixing with ordinary photons via the Compton-like process, $\gamma e^{-}\to A^{\prime }{e}^{-}$, in a nuclear reactor and detected by their interactions with the material in the active volumes of reactor neutrino experiments. We derive 95\% confidence-level upper limits on $ϵ$, the $A^{\prime }$-$\gamma$ mixing parameter, $ϵ$, for dark-photon masses below 1$\sim$MeV of $ϵ<1.3\times 10^{-5}$ and $ϵ<2.1\times 10^{-5}$, from NEOS and TEXONO experimental data, respectively. This study demonstrates the applicability of nuclear reactors as potential sources of intense fluxes of low-mass dark photons.

   hep-phhep-exPRL(2017)·27 citations
6. 06*

   Stability of pentaquarks with a two- plus three-body chromoelectric interaction

   Fl. Stancu🇧🇪

   We study the stability of pentaquarks within a schematic model based on SU(3) color symmetry, by taking into account algebraic arguments leading to a chromoelectric interaction containing two- and three-body parts. It has already been proven that such an interaction can influence the spectrum of ordinary baryons and the stability of tetraquarks and hexaquarks.

   hep-phPRD(2017)·1 citation
7. 07*

   Novel signatures for vector-like quarks

   J.A. Aguilar-Saavedra🇪🇸 · D.E. López-Fogliani🇦🇷 · C. Muñoz🇪🇸

   We consider supersymmetric extensions of the standard model with a vector-like doublet $(TB)$ of quarks with charge $2/3$ and $-1/3$, respectively. Compared to non-supersymmetric models, there is a variety of new decay modes for the vector-like quarks, involving the extra scalars present in supersymmetry. The importance of these new modes, yielding multi-top, multi-bottom and also multi-Higgs signals, is highlighted by the analysis of several benchmark scenarios. We show how the triangles commonly used to represent the branching ratios of the `standard' decay modes of the vector-like quarks involving $W$, $Z$ or Higgs bosons can be generalised to include additional channels. We give an example by recasting the limits of a recent heavy quark search for this more general case.

   hep-phhep-exJHEP(2017)·73 citations
8. 08*

   An indirect probe of higgsino world at the CEPC

   Ning Liu🇨🇳 · Lei Wu🇨🇳

   The higgsino world is one of the popular natural SUSY scenarios, in which $|\mu |\ll M_{gauginos}\ll M_{scalars}$. As such, searching for light degenerate higgsinos becomes an essential task of testing naturalness in supersymmetry (SUSY). In this work, we study the indirect effects of light higgsinos in the process $e^{+}{e}^{-}\to W^{+}{W}^{-}$ at future Higgs factories, such as Circular Electron Positron Collider (CEPC) in China. we find that the higgsino mass parameter $\mu \lesssim 210$ GeV favored by naturalness can be covered if the accuracy of the measurement of $W^{+}{W}^{-}$ production can reach 0.1\% at 240 GeV CEPC.

   hep-phhep-exEPJC(2017)·21 citations
9. 09*

   Exploring Extended Scalar Sectors with Di-Higgs Signals: A Higgs EFT Perspective

   Tyler Corbett🇦🇺 · Aniket Joglekar🇺🇸 · Hao-Lin Li🇺🇸 · Jiang-Hao Yu🇺🇸

   We consider extended scalar sectors of the Standard Model as ultraviolet-complete motivations for studying the effective Higgs self-interaction operators of the Standard Model effective field theory. We investigate all motivated heavy scalar models which generate the dimension-6 effective operator, $|H{|}^6$, at tree level and proceed to identify the full set of tree-level dimension-six operators by integrating out the heavy scalars. Of seven models which generate $|H{|}^6$ at tree level only two, quadruplets of hypercharge $Y=3Y_H$ and $Y=Y_H$, generate only this operator. Next we perform global fits to constrain relevant Wilson coefficients from the LHC single Higgs measurements as well as the electroweak oblique parameters $S$ and $T$. We find that the $T$ parameter puts very strong constraints on the Wilson coefficient of the $|H{|}^6$ operator in the triplet and quadruplet models, while the singlet and doublet models could still have Higgs self-couplings which deviate significantly from the standard model prediction. To determine the extent to which the $|H{|}^6$ operator could be constrained, we study the dihiggs signatures at the future 100 TeV collider and explore future sensitivity of this operator. Projected onto the Higgs potential parameters of the extended scalar sectors, with $3$ ab${}^{-1}$ luminosity data we will be able to explore the Higgs potential parameters in all seven models.

   hep-phJHEP(2018)·41 citations
10. 10*

    Using the (Modified) Matrix Element Method to constrain $L_{\mu }-L_{\tau }$ Interactions

    Fatemeh Elahi🇺🇸 · Adam Martin🇺🇸

    In this paper, we explore the discriminatory power of the matrix element method (MEM) in constraining the $L_{\mu }-L_{\tau }$ model at the LHC. The $Z^{\prime }$ gauge boson associated with the spontaneously broken $U(1{)}_{L_{\mu }-L_{\tau }}$ symmetry only interacts with the second and third generation of leptons at tree level, and is thus difficult to produce at the LHC. We argue that the best channels for discovering this $Z^{\prime }$ are in $Z\to 4\mu$ and $2\mu +/E_T$. Both these channels have a large number of kinematic observables, which strongly motivates the usage of a multivariate technique. The MEM is a multivariate analysis that uses the squared matrix element to quantify the likelihood of the testing hypotheses. We find that with $300{\text{fb}}^{-1}$ of integrated luminosity, we are sensitive to the couplings of $g_{Z^{\prime }}\gtrsim 0.002g_1$ and $M_{Z^{\prime }}<20\text{ GeV}$, and $g_{Z^{\prime }}\gtrsim 0.005g_1$ and $20\text{GeV}<M_{Z^{\prime }}<40\text{GeV}$, which is about an order of magnitude improvement over the cut-and-count method for the same amount of data.

    hep-phPRD(2017)·17 citations
11. 11*

    New Universality for Near-Threshold Three-Body Resonances

    Atsunari Konishi🇯🇵 · Osamu Morimatsu🇯🇵 · Shigehiro Yasui🇯🇵

    In the three-body system with one resonantly interacting pair, we study the behavior of the $S$-matrix pole near the threshold in the fourth quadrant of the unphysical complex energy plane. Our study is essentially based on the unitarity and analyticity of the $S$-matrix and employs the Alt-Grassberger-Sandhas (AGS) equations specifically for the three-body scattering problem and the dispersion relation for the inverse $T$-matrix. We find that the trajectory of the complex energy, $E$, of the $S$-matrix pole near the threshold is uniquely given by $c_0+E\log \left(-E\right)\approx 0$ or $c_0+E_R\log E_R\approx 0$, $E_I\approx \pi E_R/\log E_R$ in the fourth quadrant of the unphysical complex energy plane, in contrast to the non-unique trajectories with no resonantly interacting pair, $c_0+c_{1}E+E^2\log \left(-E\right)\approx 0$ or $E_R\approx -c_0/c_1$, $E_I\approx -\pi E_R^2/c_1$ where $E_R$ and $E_I$ are the real and imaginary parts of $E$, respectively, and $c_0$ and $c_1$ are real constants. This is a new universal behavior of the $S$-matrix near the threshold. Also, we briefly discuss implications to exotic hadron candidates.

    hep-ph3 citations
12. 12*

    Exploratory study of X(4140) in QCD sum rules

    Arzu Turkan🇹🇷 · Huseyin Dag🇹🇷

    In this work, we chose three molecular and three diquark-antidiquark currents with the quark content $c\bar{c}s\bar{s}$ and $J^{PC}=0^{++},1^{++},2^{++}$, and estimated the masses and the meson coupling constants of the ground states coupling to these currents in the framework of QCD sum rules. In operator product expansion, we considered the terms including dimension eight, and we performed pole contribution tests carefully. According to our results, all of these currents couple to the ground states with degenerate masses which are in 10 MeV vicinity of X(4140). Therefore, with a QCD sum rules analysis, it is not possible to conclude that X(4140) has a dominant molecular or diquark-antidiquark content. However, there may be three states degenerate in mass, with positive charge conjugation and different isospins.

    hep-phNPA(2019)·8 citations
13. 13*

    Diphoton Higgs signal strength in universal extra dimensions

    I. García-Jiménez🇲🇽 · J. Montaño🇧🇷 · G. I. Nápoles-Cañedo🇲🇽 · H. Novales-Sánchez🇲🇽 · J. J. Toscano🇲🇽 · E. S. Tututi🇲🇽

    The signal strength of the $gg\to H\to \gamma \gamma$ reaction in $pp$ collisions at the LHC is studied within the context of the SM with UED. The impact of an arbitrary number $n$ of UED on both the $gg\to H$ and $H\to \gamma \gamma$ subprocesses is studied. The 1-loop contributions of Kaluza-Klein excitations to these subprocesses are proportional to discrete and continuous sums, which can diverge. By implementing dimensional regularization, it is shown that discrete regularized sums can naturally be expressed as multidimensional Epstein functions, and that divergences, if exist, emerge through the poles of these functions. It is found that continuous sums converge, but the discrete ones diverge, with the exception of the $n=1$ case, in which the 1-dimensional Epstein function converges. It is argued that divergences that arise from discrete sums for $n\ge 2$ are genuine UV divergences, since they correspond to short-distance effects in the compact manifold. Then, the amplitudes are renormalized in a modern sense by incorporating interactions of canonical dimension higher than four that allow us to generate the required counterterms, which are determined using a $\overline{\mathrm{MS}}$-like renormalization scheme. We find that the $gg\to H$ subprocess is quite sensitive to both the size and the dimension of the compact manifold, but the SM prediction for $H\to \gamma \gamma$ subprocess is practically unchanged. In the $n=1$ case, it is found that the experimental constraint on the compactification scale $R^{-1}\ge 1.5$ TeV allow us to reproduce the experimental limit on the signal strength $1.01\le {\mu }_{\gamma \gamma }^{(1)}\le 1.2$. In the $n\ge 2$ cases, it is found that the experimental limit on ${\mu }_{\gamma \gamma }^{(n)}$ leads to stronger lower bounds for the compactification scale given by $R^{-1}\ge 1.55,2.45,3.57,5.10,7.25$ TeVs for $n=2,4,6,8,10$, respectively.

    hep-phJ.Phys.G(2020)·3 citations
14. 14*

    Implications of Vector Boson Scattering Unitarity in Composite Higgs Models

    Diogo Buarque Franzosi🇩🇪 · Piero Ferrarese🇩🇪

    The strong nature of Composite Higgs models manifests at high energies through the growing behavior of the scattering amplitudes of longitudinally polarized weak bosons that leads to the formation of composite resonances as well as non-resonant strong effects. In this work the unitarity of these scattering amplitudes is used as a tool to assess the profile of the composite spectrum of the theory, including non-resonant enhancements, vector resonances and the CP-even scalar excitation. These three signatures are then studied in realistic scattering processes at hadron colliders, aiming to estimate the potential to exclude dynamically motivated scenarios of Composite Higgs models.

    hep-phPRD(2017)·12 citations
15. 15*

    High-scale baryogenesis with testable neutron-antineutron oscillation and dark matter

    Pei-Hong Gu🇨🇳 · Utpal Sarkar🇮🇳

    We propose a new scenario for predicting a one-loop neutron-antineutron oscillation at a testable level, meanwhile, realizing a thermal or inflationary baryogenesis at a very high scale. Besides the standard model content, this scenario involves two real singlet scalars with very heavy masses, two color-triplet and iso-singlet scalars at the TeV scale, as well as a Majorana singlet fermion for a dark matter candidate.

    hep-phPRD(2017)·11 citations
16. 16*

    Thermalization of overpopulated systems in the 2PI formalism

    Shoichiro Tsutsui🇯🇵 · Jean-Paul Blaizot🇫🇷 · Yoshitaka Hatta🇯🇵

    Based on the two-particle irreducible (2PI) formalism to next-to-leading order in the $1/N$ expansion, we study the thermalization of overpopulated systems in scalar $O(N)$ theories with moderate coupling. We focus in particular on the growth of soft modes, and examine whether this can lead to the formation of a transient Bose-Einstein condensate (BEC) when the initial occupancy is high enough. For the value of the coupling constant used in our simulations, we find that while the system rapidly approaches the condensation threshold, the formation of a BEC is eventually hindered by particle number changing processes.

    hep-phcond-mat.quant-gasnucl-thPRD(2017)·13 citations
17. 17*

    5-Point 1PI Proper Vertex Function of Gluon and the S-Matrix Element

    Gouranga C Nayak🇺🇸

    As far as the renormalization in perturbative QCD is concerned the n-point one particle irreducible (1PI) proper vertex function is the basic building block where the ultra-violet (UV) divergence occurs when the loop momentum integration limit goes to infinity. In this paper we express the S-matrix element for the $gg\to ggg$ scattering process at all orders in coupling constant in terms of 5-point, 4-point, 3-point 1PI proper vertex functions and the (full) propagator by using the path integral formulation of QCD.

    hep-phhep-thnucl-th3 citations
18. 18*

    Isospin analysis of charmless B-meson decays

    J. Charles🇫🇷 · O. Deschamps🇫🇷 · S. Descotes-Genon🇫🇷 · V. Niess🇫🇷

    We discuss the determination of the CKM angle $\alpha$ using the non-leptonic two-body decays $B\to \pi \pi$, $B\to \rho \rho$ and $B\to \rho \pi$ using the latest data available. We illustrate the methods used in each case and extract the corresponding value of $\alpha$. Combining all these elements, we obtain the following determination of ${\alpha }_{\mathrm{dir}}=(86.2_{-4.0}^{+4.4}\cup 178.4_{-5.1}^{+3.9}{)}^{\circ }$. We assess the uncertainties associated to the breakdown of the isospin hypothesis and the choice of statistical framework in detail. We also determine the hadronic amplitudes (tree and penguin) describing the QCD dynamics involved in these decays, briefly comparing our results with theoretical expectations. For each observable of interest in the $B\to \pi \pi$, $B\to \rho \rho$ and $B\to \rho \pi$ systems, we perform an indirect determination based on the constraints from all the other observables available and we discuss the compatibility between indirect and direct determinations. Finally, we review the impact of future improved measurements on the determination of $\alpha$.

    hep-phhep-exEPJC(2017)·51 citations
19. 19*

    Enhanced neutrino emissivities in pseudoscalar-mediated Dark Matter annihilation in Neutron Stars

    M. Cermeño🇪🇸 · M. A. Pérez-García🇪🇸 · R. A. Lineros🇪🇸

    We calculate neutrino emissivities from self-annihilating dark matter ($\chi$) in the dense and hot stellar interior of a (proto)neutron star. Using a model where dark matter interacts with nucleons in the stellar core through a pseudoscalar boson ($a$) we find that the neutrino production rates from the dominant reaction channels $\chi \chi \to \nu \bar{\nu }$ or $\chi \chi \to aa$, with subsequent decay of the mediator $a\to \nu \bar{\nu }$, could locally match and even surpass those of the standard neutrinos from the modified nuclear URCA processes at early ages. We find that the emitting region can be localized in a tiny fraction of the star (less than a few percent of the core volume) and the process can last its entire lifetime for some cases under study. We discuss the possible consequences of our results for stellar cooling in light of existing dark matter constraints.

    hep-phastro-ph.SRApJ(2018)·16 citations
20. 20*

    Direct Bounds on Heavy Top-Like Quarks With Standard and Exotic Decays

    Mikael Chala🇪🇸

    Heavy vector-like quarks with electric charge $Q=2/3$ (also called \textit{heavy tops}) appear naturally in many extensions of the Standard Model. Although these typically predict the existence of further particles below the TeV scale, direct searches for heavy tops have been performed assuming that they decay only into SM particles. The aim of this paper is to overcome this situation. We consider the most constraining experimental LHC searches for vector-like quarks, including analyses of the 36 fb${}^{-1}$ of data collected in the latest run at 13 TeV of center of mass energy, as well as searches sensitive to heavy tops decaying into a new scalar, $S$. Combining all these, we derive bounds for arbitrary values of the heavy top branching ratios. A simple code that automatizes this process is also provided. At the physics level, we demonstrate that bounds on heavy tops are not inevitably weaker in the presence of new light scalars. We find that heavy tops with masses below $\sim 900$ GeV are excluded by direct searches, independently of whether they decay into $Zt,Ht,Wb$ or $St$ (with $S$ giving either missing energy of bottom quarks) or into any combination of them.

    hep-phhep-exPRD(2017)·84 citations
21. 21*

    Direct Detection of Light Dark Matter and Solar Neutrinos via Color Center Production in Crystals

    Ranny Budnik🇮🇱 · Ori Chesnovsky🇮🇱 · Oren Slone🇮🇱 · Tomer Volansky🇮🇱

    We propose a new low-threshold direct-detection concept for dark matter and for coherent nuclear scattering of solar neutrinos, based on the dissociation of atoms and subsequent creation of color center type defects within a lattice. The novelty in our approach lies in its ability to detect single defects in a macroscopic bulk of material. This class of experiments features ultra-low energy thresholds which allows for the probing of dark matter as light as $\mathcal{O}(10)$ MeV through nuclear scattering. Another feature of defect creation in crystals is directional information, which presents as a spectacular signal and a handle on background reduction in the form of daily modulation of the interaction rate. We discuss the envisioned setup and detection technique, as well as background reduction. We further calculate the expected rates for dark matter and solar neutrinos in two example crystals for which available data exists, demonstrating the prospective sensitivity of such experiments.

    hep-phPLB(2018)·107 citations
22. 22*

    Accelerating Science with Generative Adversarial Networks: An Application to 3D Particle Showers in Multi-Layer Calorimeters

    Michela Paganini🇺🇸 · Luke de Oliveira🇺🇸 · Benjamin Nachman🇺🇸

    Physicists at the Large Hadron Collider (LHC) rely on detailed simulations of particle collisions to build expectations of what experimental data may look like under different theory modeling assumptions. Petabytes of simulated data are needed to develop analysis techniques, though they are expensive to generate using existing algorithms and computing resources. The modeling of detectors and the precise description of particle cascades as they interact with the material in the calorimeter are the most computationally demanding steps in the simulation pipeline. We therefore introduce a deep neural network-based generative model to enable high-fidelity, fast, electromagnetic calorimeter simulation. There are still challenges for achieving precision across the entire phase space, but our current solution can reproduce a variety of particle shower properties while achieving speed-up factors of up to 100,000$\times$. This opens the door to a new era of fast simulation that could save significant computing time and disk space, while extending the reach of physics searches and precision measurements at the LHC and beyond.

    ↳ hep-exhep-phstat.MLPRL(2018)·254 citations
23. 23*

    Results from the OPERA Experiment

    L.Patrizii (for the OPERA Collaboration)🇮🇹

    The OPERA experiment reached its main goal by proving the appearance of ${\nu }_{\tau }$ in the CNGS ${\nu }_{\mu }$ beam. A sample of five ${\nu }_{\tau }$ candidates was collected allowing to reject the null hypothesis at $5.1\sigma$. The estimation of $\Delta m_{23}^2$ in "appearance mode" has been obtained. Updates on the search for ${\nu }_{\mu }\to {\nu }_e$ oscillations and on the search for sterile neutrino mixing in the ${\nu }_{\mu }\to {\nu }_e$ and ${\nu }_{\mu }\to {\nu }_{\tau }$ channels are also reported.

    ↳ hep-exhep-ph0 citations
24. 24*

    BICEP2 / Keck Array IX: New Bounds on Anisotropies of CMB Polarization Rotation and Implications for Axion-Like Particles and Primordial Magnetic Fields

    Keck Array · BICEP2 Collaborations: P. A. R. Ade · Z. Ahmed · R. W. Aikin · K. D. Alexander · D. Barkats · S. J. Benton · C. A. Bischoff · J. J. Bock · R. Bowens-Rubin · J. A. Brevik · I. Buder and 54 other authors

    We present the strongest constraints to date on anisotropies of cosmic microwave background (CMB) polarization rotation derived from 150 GHz data taken by the BICEP2/Keck Array CMB experiments up to and including the 2014 observing season (BK14). The definition of the polarization angle in BK14 maps has gone through self-calibration in which the overall angle is adjusted to minimize the observed TB and EB power spectra. After this procedure, the QU maps lose sensitivity to a uniform polarization rotation but are still sensitive to anisotropies of polarization rotation. This analysis places constraints on the anisotropies of polarization rotation, which could be generated by CMB photons interacting with axionlike pseudoscalar fields or Faraday rotation induced by primordial magnetic fields. The sensitivity of BK14 maps ($\sim 3\mu$K-arcmin) makes it possible to reconstruct anisotropies of the polarization rotation angle and measure their angular power spectrum much more precisely than previous attempts. Our data are found to be consistent with no polarization rotation anisotropies, improving the upper bound on the amplitude of the rotation angle spectrum by roughly an order of magnitude compared to the previous best constraints. Our results lead to an order of magnitude better constraint on the coupling constant of the Chern-Simons electromagnetic term $g_{a\gamma }\le 7.2\times 10^{-2}/H_I$ (95% confidence) than the constraint derived from the B-mode spectrum, where $H_I$ is the inflationary Hubble scale. This constraint leads to a limit on the decay constant of $10^{-6}\lesssim f_a/M_{\mathrm{pl}}$ at mass range of $10^{-33}<m_a<10^{-28}$ eV for $r=0.01$, assuming $g_{a\gamma }\sim \alpha /(2\pi f_a)$ with $\alpha$ denoting the fine structure constant. The upper bound on the amplitude of the primordial magnetic fields is 30nG (95% confidence) from the polarization rotation anisotropies.

    ↳ astro-ph.COhep-exhep-phPRD(2017)·82 citations
25. 25*

    New parameterization of the effective field theory motivated relativistic mean field model

    Bharat Kumar🇮🇳 · S. K. Singh🇮🇳 · B. K. Agrawal🇮🇳 · S. K. Patra🇮🇳

    A new parameter set is generated for finite and infinite nuclear system within the effective field theory motivated relativistic mean field (ERMF) formalism. The isovector part of the ERMF model employed in the present study includes the coupling of nucleons to the {\delta} and h̊o} mesons and the cross-coupling of h̊o} mesons to the {\sigma} and {\omega} mesons. The results for the finite and infinite nuclear systems obtained using our parameter set are in harmony with the available experimental data. We find the maximum mass of the neutron star to be 2.03M\odot? and yet a relatively smaller radius at the canonical mass, 12.69 km, as required by the available data.

    ↳ nucl-thhep-phnucl-exNPA(2017)·90 citations
26. 26*

    Weak quadrupole moments

    Bryce G. C. Lackenby🇦🇺 · Victor V. Flambaum🇦🇺

    Collective effects in deformed atomic nuclei present possible avenues of study on the non-spherical distribution of neutrons and the violation of the local Lorentz invariance. We introduce the weak quadrupole moment of nuclei, related to the quadrupole distribution of the weak charge in the nucleus. The weak quadrupole moment produces tensor weak interaction between the nucleus and electrons and can be observed in atomic and molecular experiments measuring parity nonconservation. The dominating contribution to the weak quadrupole is given by the quadrupole moment of the neutron distribution, therefore, corresponding experiments should allow one to measure the neutron quadrupoles. Using the deformed oscillator model and the Schmidt model we calculate the quadrupole distributions of neutrons, $Q_n$, the weak quadrupole moments ,$Q_W^{(2)}$, and the Lorentz Innvariance violating energy shifts in ${}^9$Be, ${}^{21}$Ne , ${}^{27}$Al, ${}^{131}$Xe, ${}^{133}$Cs, ${}^{151}$Eu, ${}^{153}$Eu, ${}^{163}$Dy, ${}^{167}$Er, ${}^{173}$Yb, ${}^{177}$Hf, ${}^{179}$Hf, ${}^{181}$Ta, ${}^{201}$Hg and ${}^{229}$Th.

    ↳ nucl-thhep-phphysics.atom-phJ.Phys.G(2018)·10 citations
27. 27*

    Status of New Physics searches with $b\to s{\ell }^{+}{\ell }^{-}$ transitions @ LHCb

    Simone Bifani🇬🇧

    Rare decays of heavy-flavoured particles provide an ideal laboratory to look for deviations from the Standard Model, and explore energy regimes beyond the LHC reach. Decays proceeding via electroweak penguin diagrams are excellent probes to search for New Physics, and $b\to s{\ell }^{+}{\ell }^{-}$ processes are particularly interesting since they give access to many observables such as branching fractions, asymmetries and angular observables. Recent results from the LHCb experiment are reviewed.

    ↳ hep-exhep-ph17 citations
28. 28*

    Fermi acceleration along the orbit of {\eta} Carinae

    Matteo Balbo · Roland Walter🇨🇭

    The {\eta} Carinae binary system hosts the most massive stars with the highest known mass-loss rate. Its dense wind encounters the faster wind expelled by the companion, dissipating mechanical energy in the shock, accelerating particles up to relativistic energies and producing high-energy (HE) {\gamma}-rays. We used the first 7-year data of the Fermi LAT which span two passages of {\eta} Carinae at periastron. We extracted low and HE light curves and spectra in different orbital phase bins using the new PASS8 pipeline. We used particle acceleration in hydrodynamic simulations of the system in a multi-cell geometry and compared the prediction with the observations. The {\gamma}-ray emission location is compatible with {\eta} Carinae. Two emission components are distinguished. The low-energy (LE) one cuts off below 10 GeV and its flux, modulated by the orbital motion, varies by a factor < 2. Short-term variability occurs at periastron. The HE component flux varies by a factor 3-4 but differently during the two periastrons. The variabilities observed at LE and HE during the first half of the observations, match the prediction of the simulation, assuming a surface magnetic field of 500 G. The HE component and the thermal X-ray emission were weaker than expected around the second periastron suggesting a modification of the wind density in the inner wind collision region (WCR). Diffuse shock acceleration in the WCR provides a convincing match to the observations and new diagnostic tools to probe the geometry and energetics of the system. Further observations are required to explain the periastron-to-periastron HE variability and to associate it firmly with hadronic origin. {\eta} Carinae is a pevatron at periastron. Its $\nu$ flux can be detected by IceCube after many years of observations. Orbital modulations of the HE component can be distinguished from those of photo absorption by CTA.

    ↳ astro-ph.HEastro-ph.SRhep-phAstron.Astrophys.(2017)·30 citations
29. 29*

    Discovery probability of next-generation neutrinoless double-$\beta$ decay experiments

    Matteo Agostini🇮🇹 · Giovanni Benato🇺🇸 · Jason A. Detwiler🇺🇸

    The Bayesian discovery probability of future experiments searching for neutrinoless double-$\beta$ decay is evaluated under the popular assumption that neutrinos are their own antiparticles. A Bayesian global fit is performed to construct a probability distribution for the effective Majorana mass, the observable of interest for these experiments. This probability distribution is then combined with the sensitivity of each experiment derived from a heuristic counting analysis. The discovery probability is found to be higher than previously considered, but strongly depends on whether the neutrino mass ordering is normal or inverted. For the inverted ordering, next-generation experiments are likely to observe a signal already during their first operational stages. Even for the normal ordering, in the absence of neutrino mass mechanisms that drive the lightest state or the effective Majorana mass to zero, the probability of discovering neutrinoless double-$\beta$ decay can reach $\sim$50% or more in the most promising experiments.

    ↳ hep-exhep-phnucl-exPRD(2017)·209 citations
30. 30*

    Analysis of Ten Years of Radon-Chain Decay Measurements: Evidence of Solar Influences and Inferences Concerning Solar Internal Structure and the Role of Neutrinos

    P.A. Sturrock🇺🇸 · G. Steinitz🇮🇱 · E. Fischbach🇺🇸

    Gamma radiation associated with radon decay exhibits variations in both time of year and time of day. The annual oscillation has its maximum value in June, suggestive of a galactic influence. Measurements made at midnight show strong evidence of an influence of solar rotation, but measurements made at noon do not. We find several pairs of oscillations with frequencies separated by 1 cycle per year that is suggestive of an influence of rotation that is oblique with respect to the normal to the ecliptic. We suggest that beta decays may be stimulated by neutrinos and that the decay products tend to travel in the same direction as the neutrinos. We estimate the relevant cross section.

    ↳ astro-ph.SRhep-ph7 citations
31. 31*

    Hyperinflation

    Adam R. Brown🇺🇸

    A model of cosmological inflation is proposed in which field space is a hyperbolic plane. The inflaton never slow-rolls, and instead orbits the bottom of the potential, buoyed by a centrifugal force. Though initial velocities redshift away during inflation, in negatively curved spaces angular momentum naturally starts exponentially large and remains relevant throughout. Quantum fluctuations produce perturbations that are adiabatic and approximately scale invariant; strikingly, in a certain parameter regime the perturbations can grow double-exponentially during horizon crossing.

    ↳ hep-thastro-ph.COgr-qchep-phPRL(2018)·176 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.