Fri·Feb 8, 2019Friday·February 8, 2019

1. 01*

   Sub-GeV Dark Matter in Superfluid He-4: an Effective Theory Approach

   Francesca Acanfora🇮🇹 · Angelo Esposito🇨🇭 · Antonio D. Polosa🇮🇹

   We employ an effective field theory to study the detectability of sub-GeV dark matter through its interaction with the gapless excitations of superfluid helium-4. In a quantum field theory language, the possible interactions between the dark matter and the superfluid phonon are solely dictated by symmetry. We compute the rate for the emission of one and two phonons, and show that these two observables combined allow for a large exclusion region for the dark matter masses. Our approach allows a direct calculation of the differential distributions, even though it is limited only to the region of softer phonon excitations, where the effective field theory is well defined. The method presented here is easily extendible to different models of dark matter.

   hep-phEPJC(2019)·55 citations
2. 02*

   Process dependence of the gluon Sivers function in inclusive $pp$ collisions: phenomenology

   U. D'Alesio🇮🇹 · C. Flore🇮🇹 · F. Murgia🇮🇹 · C. Pisano🇮🇹 · P. Taels🇮🇹

   Within the so-called color gauge invariant generalized parton model, a TMD scheme including initial- (ISI) and final-state (FSI) interactions, we present a phenomenological analysis of available SSA data for pion and $D$-meson production in $pp$ collisions. This allows us, for the first time, to put a preliminary constraint on the two universal types of gluon Sivers function entering the model. Predictions for SSAs in $J/\psi$ and direct photon production, as well as a comparison with the simpler generalized parton model (without ISIs and FSIs), are also presented.

   hep-phPoS(2019)·1 citation
3. 03*

   Isoscalar and isovector kaon form factors from $e^{+}{e}^{-}$ and $\tau$ data

   K.I. Beloborodov🇷🇺 · V.P. Druzhinin🇷🇺 · S.I. Serednyakov🇷🇺

   The recent precise measurements of the $e^{+}{e}^{-}\to K_S{K}_L$ and $e^{+}{e}^{-}\to K^{+}{K}^{-}$ cross sections and the hadronic spectral function of the ${\tau }^{-}\to K^{-}{K}_S{\nu }_{\tau }$ decay are used to extract the isoscalar and isovector electromagnetic kaon form factors and their relative phase in a model independent way. The experimental results are compared with a fit based on the vector-meson-dominance model.

   hep-phEPJ Web Conf.(2019)·6 citations
4. 04*

   Heavy flavour Langevin diffusion with the chromo-electromagnetic field fluctuations in the quark-gluon plasma

   Ashik Ikbal Sheikh🇮🇳 · Zubayer Ahammed🇮🇳

   The chromo-electromagnetic field is produced due to the motion of partons in a quark-gluon plasma created by relativistic heavy-ion collisions. The fluctuations in the produced chromo-electromagnetic field are important, since they cause heavy quarks to gain energy in the low velocity limit. We study the effect of such fluctuations on heavy quark diffusion in quark-gluon plasma within the framework of Langevin dynamics under the background matter described by the ($3+1$)-dimensional relativistic viscous hydrodynamics. Theoretical calculations of the nuclear modification factor ($R_{AA}$) of heavy mesons ($D$ and $B$ mesons), with the effect of these fluctuations, are compared with experimental measurements in $Au-Au$ collisions at $\sqrt{s_{NN}}=200$ GeV by the STAR experiment at the BNL Relativistic Heavy Ion Collider (RHIC) and $Pb-Pb$ collisions at $\sqrt{s_{NN}}=2.76$ and $5.02$ TeV by the ALICE and CMS experiments at the CERN Large Hadron Collider (LHC). We find a significant effect of these fluctuations in describing the the measured $R_{AA}$ of $D$ and $B$ mesons in both RHIC and LHC energies.

   hep-phnucl-thEPJA(2020)·5 citations
5. 05*

   $K^0\Lambda$ Photoproduction with Nucleon Resonances

   Sang-Ho Kim🇰🇷 · Hyun-Chul Kim🇰🇷

   We investigate the reaction mechanism of $K^0\Lambda$ photoproduction off the neutron target, i.e., $\gamma n\to K^0\Lambda$, in the range of $W\approx 1.6-2.2$ GeV. We employ an effective Lagrangian method at the tree-level Born approximation combining with a Regge approach. As a background, the $K^{\ast }$-Reggeon trajectory is taken into account in the $t$ channel and $\Lambda$ and $\Sigma$ hyperons in the $u$-channel Feynman diagram. In addition, the role of various nucleon resonances listed in the Particle Data Group (PDG) is carefully scrutinized in the $s$ channel where the resonance parameters are extracted from the experimental data and constituent quark model. We present our numerical results of the total and differential cross sections and compare them with the recent CLAS data. The effect of the narrow nucleon resonance $N(1685,1/2^{+})$ on cross sections is studied in detail and it turns out that its existence is essential in $K^0\Lambda$ photoproduction to reproduce the CLAS data.

   hep-phhep-exnucl-exnucl-thJPS Conf.Proc.(2019)·0 citations
6. 06*

   Anisotropic pressure of deconfined QCD matter in presence of strong magnetic field within one-loop approximation

   Bithika Karmakar🇮🇳 · Ritesh Ghosh🇮🇳 · Aritra Bandyopadhyay🇧🇷 · Najmul Haque🇮🇳 · Munshi G Mustafa🇮🇳

   Considering the general structure of the two point functions of quarks and gluons, we compute the free energy and pressure of a strongly magnetized hot and dense QCD matter created in heavy-ion collisions. In presence of strong magnetic field we found that the deconfined QCD matter exhibits a paramagnetic nature. One gets different pressure in a direction parallel and perpendicular to magnetic field due to the magnetization acquired by the system. We obtain both longitudinal and transverse pressure, and magnetization of a hot deconfined QCD matter in presence of magnetic field. We have used hard thermal loop approximation (HTL) for heat bath. We obtained completely analytic expression for pressure and magnetization under certain approximation. Various divergences appearing in free energy are regulated using appropriate counter terms. The obtained anisotropic pressure may be useful for magnetohydrodynamics description of a hot and dense deconfined QCD matter produced in heavy-ion collisions.

   hep-phhep-latnucl-thPRD(2019)·70 citations
7. 07*

   Radiative Axion Inflation

   Andrea Caputo🇪🇸

   Planck data robustly exclude the simple $\lambda {\varphi }^4$ scenario for inflation. This is also the case for models of Axion Inflation in which the inflaton field is the radial part of the Peccei-Quinn complex scalar field. In this letter we show that for the KSVZ model it is possible to match the data taking into account radiative corrections to the tree level potential. After writing down the 1-loop Coleman-Weinberg potential, we show that a radiative plateau is easily generated thanks to the fact that the heavy quarks are charged under $SU(3{)}_c$ in order to solve the strong CP problem. We also give a numerical example for which the inflationary observables are computed and the heavy quarks are predicted to have a mass $m_Q\gtrsim 10^{3}TeV$.

   hep-phastro-ph.COPLB(2019)·17 citations
8. 08*

   Magnetic field production at a first-order electroweak phase transition

   Yiyang Zhang🇺🇸 · Tanmay Vachaspati🇺🇸 · Francesc Ferrer🇺🇸

   We study the generation of magnetic field seeds during a first-order electroweak phase transition, by numerically evolving the classical equations of motion of the bosonic electroweak theory on the lattice. The onset of the transition is implemented by the random nucleation of bubbles with an arbitrarily oriented Higgs field in the broken phase. We find that about 10% of the latent heat is converted into magnetic energy, with most of the magnetic fields being generated in the last stage of the phase transition when the Higgs oscillates around the true vacuum. The energy spectrum of the magnetic field has a peak that shifts towards larger length scales as the phase transition unfolds. By the end of our runs the peak wavelength is of the order of the bubble percolation scale, or about a third of our lattice size.

   hep-phastro-ph.COPRD(2019)·42 citations
9. 09*

   "Invisible" axion rolling through the QCD phase transition

   Jihn E. Kim🇰🇷 · Se-Jin Kim

   The origin of `invisible' axion in four dimensional effective beyond-standard models from string compactification is discussed and its refined passover through the QCD phase transition is presented toward a reliable estimate of the current axion energy density in terms of the initial misalignment angle ${\bar{\theta }}_1$. The explicit examples are presented in a flipped SU(5) GUT model. This allows to introduce a flavor symmetry through string compactification, and hence we also comment on the source of flavor symmetries from string compactification and attempts to fit the resulting Yukawa couplings to the observed Cabibbo-Kobayashi-Maskawa and Pontecorvo-Maki-Nakagawa-Sakata matrices.

   hep-phhep-exPoS(2019)·1 citation
10. 10*

    Constraining Rapidly Oscillating Scalar Dark Matter Using Dynamic Decoupling

    Shahaf Aharony🇮🇱 · Nitzan Akerman🇮🇱 · Roee Ozeri🇮🇱 · Gilad Perez🇮🇱 · Inbar Savoray🇮🇱 · Ravid Shaniv🇮🇱

    We propose and experimentally demonstrate a method for detection of light scalar Dark Matter (DM), through probing temporal oscillations of fundamental constants in an atomic optical transition. Utilizing the quantum information notion of Dynamic Decoupling (DD) in a table-top setting, we are able to obtain model-independent bounds on variations of $\alpha$ and $m_e$ at frequencies up to the MHz scale. We interpret our results to constrain the parameter space of light scalar DM field models. We consider the generic case, where the couplings of the DM field to the photon and to the electron are independent, as well as the case of a relaxion DM model, including the scenario of a DM boson star centered around Earth. Given the particular nature of DD, allowing to directly observe the oscillatory behaviour of coherent DM, and considering future experimental improvements, we conclude that our proposed method could be complimentary to, and possibly competitive with, gravitational probes of light scalar DM.

    hep-phphysics.atom-phPRD(2021)·63 citations
11. 11*

    Stability of the vacuum as constraint on $U$(1) extensions of the standard model

    Zoltán Péli🇭🇺 · Zoltán Trócsányi🇭🇺

    In the standard model the running quartic coupling becomes negative during its renormalization group flow, which destabilizes the vacuum. We consider U(1) extensions of the standard model, with an extra complex scalar field and a Majorana-type neutrino Yukawa coupling. These additional couplings affect the renormalization group flow of the quartic couplings. We compute the beta-functions of the extended model at one-loop order in perturbation theory and study how the parameter space of the new scalar couplings can be constrained by the requirement of stable vacuum and perturbativity up to the Planck scale.

    hep-phhep-th6 citations
12. 12*

    An in-depth analysis of $b\to c(s)$ semileptonic observables with possible $\mu -\tau$ mixing

    Srimoy Bhattacharya🇮🇳 · Aritra Biswas🇮🇳 · Zaineb Calcuttawala🇮🇳 · Sunando Kumar Patra🇮🇳

    In a couple of recent publications ( arXiv:1706.08437 and arXiv:1712.01593 ), the authors attempted to achieve simultaneous explanation of the persistent flavor anomalies in $b\to s$ and $b\to c$ semileptonic decays with a minimal scheme by using only three unknown new parameters. The analysis was obtained with a handful of precise observables. Motivated by their proposal, in this paper we reanalyze the models proposed in the aforementioned papers with a total of 170 observables from those channels including newly available measurements, correlated theoretical results, and constraints. We validate our results by searching for the most influential points and outliers. By analyzing the parameter spaces and their relationship with the constraints, we gain new insight and statistical significance in those models. We also provide a new and precise calculation of $R(J/\Psi )$, obtained during the analysis.

    hep-phhep-ex14 citations
13. 13*

    Deriving the Inflaton in Compactified M-theory with a De Sitter Vacuum

    Gordon Kane🇺🇸 · Martin Wolfgang Winkler🇸🇪

    Compactifying M-theory on a manifold of $G_2$ holonomy gives a UV complete 4D theory. It is supersymmetric, with soft supersymmetry breaking via gaugino condensation that simultaneously stabilizes all moduli and generates a hierarchy between the Planck and the Fermi scale. It generically has gauge matter, chiral fermions, and several other important features of our world. Here we show that the theory also contains a successful inflaton, which is a linear combination of moduli closely aligned with the overall volume modulus of the compactified $G_2$ manifold. The scheme does not rely on ad hoc assumptions, but derives from an effective quantum theory of gravity. Inflation arises near an inflection point in the potential which can be deformed into a local minimum. This implies that a de Sitter vacuum can occur in the moduli potential even without uplifting. Generically present charged hidden sector matter generates a de Sitter vacuum as well.

    ↳ hep-thastro-ph.COhep-phPRD(2019)·10 citations
14. 14*

    Constraints on millicharged dark matter and axion-like particles from timing of radio waves

    Andrea Caputo🇪🇸 · Laura Sberna🇨🇦 · Miguel Frias🇪🇸 · Diego Blas🇬🇧 · Paolo Pani🇮🇹 · Lijing Shao🇨🇳 · Wenming Yan🇨🇳

    We derive novel constraints on millicharged dark matter and ultralight axion-like particles using pulsar timing and fast radio burst observations. Millicharged dark matter affects the dispersion measure of the time of arrival of radio pulses in a way analogous to free electrons. Light pseudo-scalar dark matter, on the other hand, causes the polarization angle of radio signals to oscillate. We show that current and future data can set strong constraints in both cases. For dark matter particles of charge $ϵe$, these constraints are $ϵ/m_{\mathrm{milli}}\lesssim 10^{-8}{\mathrm{eV}}^{-1}$, for masses $m_{\mathrm{milli}}\gtrsim 10^{-6}$eV. For axion-like particles, the analysis of signals from pulsars yields constraints in the axial coupling of the order of $g/m_a\lesssim 10^{-13}{\mathrm{GeV}}^{-1}/(10^{-22}\mathrm{eV})$. Both bounds scale as $(\rho /{\rho }_{\mathrm{dm}}{)}^{1/2}$ if the energy density $\rho$ of the components is a fraction of the total dark matter energy density ${\rho }_{\mathrm{dm}}$. We do a detailed study of both effects using data from two samples of pulsars in the galaxy and in globular clusters, as well as data from FRB 121102 and PSR J0437$-$4715. We show that in both cases actual pulsar data constrain a new region of the parameter space for these models, and will improve with future pulsar-timing observations.

    ↳ astro-ph.COastro-ph.HEgr-qchep-phPRD(2019)·105 citations
15. 15*

    Fundamental physics constraints from testing the stability of the fine-structure constant with the ELTs

    A. C. O. Leite🇵🇹 · C. J. A. P. Martins🇵🇹 · P. Molaro🇮🇹 · C. S. Alves🇵🇹 · T. A. Silva🇵🇹

    The increased collecting area of the ELTs will bring fainter high-z targets within the reach of high-resolution ultra-stable spectrographs, thus enabling a new generation of precision consistency tests, including tests of the stability of nature's fundamental couplings. For example, the stability of the fine-structure constant can be tested by looking at metal absorption lines produced by the intervening clouds along the line of sight of distant quasars. In this contribution, we discuss the performance that can be expected from the ELTs in testing the stability of the fine-structure constant, based on the early ESPRESSO observations, and some comparative forecasts of the impact of these measurements for representative models of fundamental physics and cosmology.

    ↳ astro-ph.COhep-phphysics.ins-det2 citations
16. 16*

    Les Houches Lectures on Effective Field Theories for Nuclear and (some) Atomic Physics

    U. van Kolck🇫🇷

    These lectures are a pedagogical -- not comprehensive -- introduction to the applications of effective field theory in the context of nuclear and atomic physics. A common feature of these applications is the interplay between nonperturbative physics (needed at leading order to produce nonrelativistic bound states and resonances) and controlled perturbative corrections (crucial for predictive power). The essential ideas are illustrated with the simplest nuclear EFT, Pionless EFT, which contains only contact interactions and, with minor changes, can be adapted to certain atomic systems. This EFT exploits the two-body unitarity limit, where renormalization leads to discrete scale invariance in systems of three and more bodies. Remarkably complex structures then arise from very simple leading-order interactions. Some of the challenges and rewards of including long-range forces -- pion exchange in Chiral EFT for nuclear systems or Van der Waals forces between atoms -- are briefly described.

    ↳ nucl-thcond-mat.quant-gashep-phLes Houches Lect.Notes(2020)·5 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.