Wed·Dec 18, 2019Wednesday·December 18, 2019

1. 01*

   Heavy exotic scalar meson $T_{bb;\bar{u}\bar{s}}^{-}$

   S. S. Agaev🇦🇿 · K. Azizi🇮🇷 · B. Barsbay🇹🇷 · H. Sundu🇹🇷

   The spectroscopic parameters and decay channels of the scalar tetraquark $T_{bb;\overline{u}\overline{s}}^{-}$ (in what follows $T_{b:\overline{s}}^{-}$) are investigated. The mass and coupling of the $T_{b:s}^{-}$ are calculated using the two-point sum rules by taking into account quark, gluon and mixed vacuum condensates up to dimension 10. Our result for its mass $m=(10250\pm 270)\mathrm{MeV}$ demonstrates that $T_{b:\overline{s}}^{-}$ is stable against the strong and electromagnetic decays. Therefore to find the width and mean lifetime of the $T_{b:\overline{s}}^{-}$, we explore its dominant weak decays generated by the transition $b\to W^{-}c$. These channels embrace the semileptonic decay $T_{b:\overline{s}}^{-}\to Z_{bc;\overline{u}\overline{s}}^{0}l{\overline{\nu }}_l$ and nonleptonic modes $T_{b:\overline{s}}^{-}\to Z_{bc;\overline{u}\overline{s}}^0{\pi }^{-}(K^{-},D^{-},D_s^{-})$, which at the final state contain the scalar tetraquark $Z_{bc;\overline{u}\overline{s}}^0$. Key quantities to compute partial widths of the weak decays are the form factors $G_1(q^2)$ and $G_2(q^2)$: they determine differential rate $d\Gamma /d{q}^2$ of the semileptonic and partial widths of the nonleptonic processes, respectively. These form factors are extracted from relevant three-point sum rules at momentum transfers $q^2$ accessible for such analysis. By means of the fit functions $F_{1(2)}(q^2)$ they are extrapolated to cover the whole integration region $m_l^2\le q2\le (m-\tilde{m}{)}^2$, where $\tilde{m}$ is the mass of $Z_{bc;\overline{u}\overline{s}}^0$. Predictions for the full width ${\Gamma }_{\mathrm{full}}=(15.21\pm 2.59)\times 10^{-10}\mathrm{MeV}$ and mean lifetime $4.33_{-0.63}^{+0.89}\times 10^{-13}\mathrm{s}$ of the $T_{b:s}^{-}$ are useful for experimental and theoretical investigations of this exotic meson.

   hep-phhep-exhep-latPRD(2020)·29 citations
2. 02*

   Higgs-Squark-Slepton Inflation from the MSSM

   Zurab Tavartkiladze🇬🇪

   The inflation within the MSSM is proposed, where the inflaton field is a combination of the Higgs, squark and slepton states. While the inflationary phase is fully governed by the electron Yukawa superpotential coupling, the fields' condensates float along the flat $D$-term trajectory. This predicts the MSSM parameter $\tan \beta \simeq 13.1$ determined via the value of the curvature perturbation amplitude. The values of the scalar spectral index and the tensor-to-scalar ratio are predicted to be $n_s\simeq 0.966$ and $r=0.00118$. The postinflation reheating of the Universe proceeds by the radiative decay of the inflaton to the two gluons ($\varphi \to gg$) with the reheating temperature $T_r\simeq 1.4\cdot 10^7$ GeV.

   hep-phastro-ph.COgr-qchep-thPRD(2020)·2 citations
3. 03*

   Recent developments in $q_T$ subtraction: EW corrections and power suppressed contributions

   Luca Buonocore🇨🇭

   The $q_T$ subtraction formalism represents a well established and successful technique to deal with the computation of QCD radiative corrections up to NNLO (and beyond) for a large class of processes relevant at the LHC. We have explored the possibility to apply $q_T$ subtraction to the computation of EW corrections with the (final) aim to develop a subtraction formalism suitable for the computation of mixed QCD-EW corrections. We present numerical results for the complete NLO EW corrections to the Drell-Yan production of a massive lepton pair. Furthermore, we have investigated the structure of the power suppressed contributions at small-$q_T$ in this process and we present new analytical results on the effects of the soft radiation emitted off a charged massive final state.

   hep-phnucl-th0 citations
4. 04*

   Direct detection rate of heavy Higgsino-like and Wino-like dark matter

   Qing Chen🇺🇸 · Richard J. Hill🇺🇸

   A large class of viable dark matter models contain a WIMP candidate that is a component of a new electroweak multiplet whose mass $M$ is large compared to the electroweak scale $m_W$. A generic amplitude-level cancellation in such models yields a severe suppression of the cross section for WIMP-nucleon scattering, making it important to assess the impact of formally subleading effects. The power correction of order $m_W/M$ to the heavy WIMP limit is computed for electroweak doublet (Higgsino-like) dark matter candidates, and a modern model of nuclear modifications to the free nucleon cross section is evaluated. Corrections to the pure Higgsino limit are determined by a single parameter through first order in the heavy WIMP expansion. Current and projected experimental bounds on this parameter are investigated. The direct detection signal in the pure Higgsino limit remains below neutrino backgrounds for WIMPs in the TeV mass range. Nuclear corrections are applied also to the heavy Wino case, completing the investigation of combined subleading effects from perturbative QCD, $1/M$ power corrections, and nuclear modifications.

   hep-phastro-ph.COPLB(2020)·29 citations
5. 05*

   Bases of massless EFTs via momentum twistors

   Adam Falkowski🇫🇷

   I present a novel method of deriving a basis of contact terms in massless effective field theories (EFTs). It relies on the parametrization of $N$-body kinematics via the so-called momentum twistors. A basis is constructed directly at the amplitude level, without using fields or Lagrangians. The method consists in recasting any local contact term as a sum of rational functions built from Lorentz-invariant contractions of momentum twistors. The end result is equivalent to constructing a basis of higher-dimensional operators in an EFT Lagrangian, however it is considerably simpler, especially for theories with higher-spin particles. The method is applied to contact terms in 4-point amplitudes. I provide a compact algebraic formula for basis elements for any helicity configuration of the external particles, and I illustrate its usage with several physically relevant examples.

   hep-phhep-th29 citations
6. 06*

   A global perspective on searches for Electric Dipole Moments

   Guillaume Pignol🇫🇷

   Many experiments are underway in the world to search for a non-zero electric dipole moment (EDM) of a particle with spin 1/2 such as the neutron or the electron. Finding an EDM would reveal new sources of CP violation. EDM measurements are motivated by the high sensitivity to new physics beyond the Standard Model. They are relevant to find the explanation for the matter-antimatter asymmetry of the Universe. A variety of programs with different systems are being pursued, with free neutrons, diamagnetic atoms, paramagnetic systems, and charged particles in storage rings. This article presents a basic introduction of the subject and attempts to compile the ongoing projects.

   hep-phhep-exnucl-ex2 citations
7. 07*

   Completing the four-body contributions to $\bar{B}\to X_s\gamma$ at NLO

   Tobias Huber🇩🇪 · Lars-Thorben Moos (Siegen U)🇩🇪

   We report on the status of the ongoing calculation of multiparticle contributions to the inclusive radiative $\bar{B}\to X_s\gamma$ decay at next-to leading order. This effort amounts to the evaluation of the four-particle process $b\to s\bar{q}q\gamma$ at the one-loop level, supplemented by the corresponding five-particle tree-level cuts $b\to s\bar{q}q\gamma +g$ of the gluon bremsstrahlung. Knowledge of these pieces will formally complete the $\bar{B}\to X_s\gamma$ decay at the next-to-leading order. The different steps such as the generation of the amplitude, its renormalization, and the treatment of occurring IR-divergences are discussed. Moreover, we elaborate on the subtleties that arise when treating ${\gamma }_5$ in $D$ dimensions.

   hep-phPoS(2019)·1 citation
8. 08*

   The HepMC3 Event Record Library for Monte Carlo Event Generators

   Andy Buckley🇬🇧 · Philip Ilten🇬🇧 · Dmitri Konstantinov🇷🇺 · Leif Lönnblad🇸🇪 · James Monk🇩🇰 · Witold Pokorski🇨🇭 · Tomasz Przedzinski🇵🇱 · Andrii Verbytskyi🇩🇪

   In high-energy physics, Monte Carlo event generators (MCEGs) are used to simulate the interactions of high energy particles. MCEG event records store the information on the simulated particles and their relationships, and thus reflects the simulated evolution of physics phenomena in each collision event. We present the HepMC3 library, a next-generation framework for MCEG event record encoding and manipulation, which builds on the functionality of its widely-used predecessors to enable more sophisticated algorithms for event-record analysis. By comparison to previous versions, the event record structure has been simplified, while adding the possibility to encode arbitrary information. The I/O functionality has been extended to support common input and output formats of various HEP MCEGs, including formats used in Fortran MCEGs, the formats established by the HepMC2 library, and binary formats such as ROOT; custom input or output handlers may also be used. HepMC3 is already supported by popular modern MCEGs and can replace the older HepMC versions in many others.

   hep-phComput.Phys.Commun.(2021)·129 citations
9. 09*

   An Effective Theory of Quarkonia in QCD Matter

   Yiannis Makris🇮🇹 · Ivan Vitev🇺🇸

   The problem of quarkonium production in heavy ion collisions presents a set of unique theoretical challenges -- from the relevant production mechanism of $J/\psi$ and ${\rm Y}$ to the relative significance of distinct cold and hot nuclear matter effects in the observed attenuation of quarkonia. Inthese proceedings we summarize recent work on the generalization of non-relativistic Quantum Chromodynamics (NRQCD) to include off-shell gluon (Glauber/Coulomb) interactions in strongly interacting matter. This new effective theory provides for the first time a universal microscopic description of the in-medium interaction of heavy quarkonia, consistently applicable to a range of phases such as cold nuclear matter, dense hadron gas, and quark-gluon plasma. It is an important step forward in understanding the common trends in proton-nucleus and nucleus-nucleus data on quarkonium suppression. We derive explicitly the leading and sub-leading interaction terms in the Lagrangian and show the connection of the leading result to existing phenomenology.

   hep-phnucl-thNPA(2021)·6 citations
10. 10*

    Global cosmic string networks as a function of tension

    Vincent B. Klaer🇩🇪 · Guy D. Moore🇩🇪

    We investigate the properties of global cosmic string networks as a function of the ratio of string tension to Goldstone-field coupling, and as a function of the Hubble damping strength. Our results show unambiguously that the string density is sensitive to this ratio. We also find that existing semi-analytical (one-scale) models must be missing some important aspect of the network dynamics. Our results point the way towards improving such models.

    hep-phhep-latJCAP(2020)·55 citations
11. 11*

    Particle Ratios in a Multi Component Non-Ideal Hadron Resonance Gas

    Rameez Ahmad Parra🇮🇳 · Saeed Uddin🇮🇳 · Waseem Bashir🇮🇳 · Inam-ul Bashir🇮🇳

    We have considered formation of a multi component non-ideal hot and dense gas of hadronic resonances in the ultra-relativistic heavy-ion collisions. In the statistical thermal model approach the equation of state (EoS) of the non interacting ideal hadron resonance gas (IHRG) does not incorporate either the attractive part or the short range repulsive part of the baryonic interaction. On the other hand in the non-ideal hadron resonance gas (NIHRG) model we can incorporate these interactions using the Van der Waals (VDW) type approach. Studies have been made to see its effect on the critical parameters of the quark-hadron phase transition. However, it can also lead to modifications in the calculated relative particle yields. In this paper we have attempted to understand the effect of such Van der Waals type interactions on the relative particle yields and also studied their dependences on the system thermal parameters, such as the temperature and baryon chemical potential ({\mu}_B). We have also taken into account the decay contributions of the heavier resonances. These results on particle ratios are compared with the corresponding results obtained from the point-like i.e. non interacting IHRG model. It is found that the particle ratios get modified by incorporating the Van der Waals type interactions, especially in a baryon rich system which is expected to be formed at lower RHIC energies, SPS energies and in the forthcoming CBM experiments due to high degree of nuclear stopping in these experiments.

    hep-phnucl-thAdv.High Energy Phys.(2023)·3 citations
12. 12*

    New constraints for nuclear parton distribution functions from hadron-nucleus collision processes

    Petja Paakkinen🇫🇮

    This work studies collinearly factorizable nuclear parton distribution functions (nPDFs) in perturbative Quantum Chromodynamics (QCD) at next-to-leading order in the light of hadron-nucleus collision data which have not been included in nPDF analyses previously. The aim is at setting new constraints on the nuclear modifications of the gluon distribution and on the flavour separation of quark nuclear modifications. The introductory part provides an outline of the theoretical framework of QCD collinear factorization and the used statistical methods and relates the work presented here to other similar contemporary analyses. As a result, a new set of nPDFs, EPPS16, is presented, including for the first time electroweak-boson and dijet production data from CERN-LHC proton-lead collisions and allowing a full flavour separation in the fit. The flavour separation is constrained with Drell-Yan dilepton-production data from fixed target pion-nucleus experiments and neutrino-nucleus deep-inelastic scattering data, which are shown to give evidence for the similarity of the u and d valence-quark nuclear modifications. For studying the gluon degrees of freedom, collider data are essential and in the EPPS16 analysis new constraints are derived from the dijet production at the LHC. Possible further constraints for the gluons are investigated in terms of the LHC data on nuclear modification ratios of dijet and D-meson production. Using a non-quadratically improved Hessian reweighting method, these measurements are found to put stringent constraints on the gluon modifications in the lead nucleus, reaching smaller values of the nucleon momentum fraction than previously accessible. A study on the future prospects of constraining nPDFs within a multi-observable approach with the BNL-RHIC is also given.

    hep-phJYU Dissertations 115, 2019, ISBN:978-951…·1 citation
13. 13*

    Probing the Sivers function with an unpolarized target: GTMD distributions and the Odderons

    Renaud Boussarie🇺🇸 · Yoshitaka Hatta🇺🇸 · Lech Szymanowski🇵🇱 · Samuel Wallon🇫🇷

    It is commonly believed that the Sivers function has uniquely to do with processes involving a transversely polarized nucleon. In this paper we show that it is not necessarily the case. We demonstrate that exclusive pion production in $un$polarized electron-proton scattering in the forward region is a direct probe of the gluon Sivers function due to its connection to the QCD Odderon.

    hep-phhep-exnucl-exnucl-thPRL(2020)·48 citations
14. 14*

    Opening the 1Hz axion window

    David J. E. Marsh🇩🇪 · Wen Yin🇰🇷

    An axion-like particle (ALP) with mass $m_{\varphi }\sim 10^{-15}$eV oscillates with frequency $\sim$1 Hz. This mass scale lies in an open window of astrophysical constraints, and appears naturally as a consequence of grand unification (GUT) in string/M-theory. However, with a GUT-scale decay constant such an ALP overcloses the Universe, and cannot solve the strong CP problem. In this paper, we present a two axion model in which the 1 Hz ALP constitutes the entirety of the dark matter (DM) while the QCD axion solves the strong CP problem but contributes negligibly to the DM relic density. The mechanism to achieve the correct relic densities relies on low-scale inflation ($m_{\varphi }\lesssim H_{\inf }\lesssim 1$ MeV), and we present explicit realisations of such a model. The scale in the axion potential leading to the 1 Hz axion generates a value for the strong CP phase which oscillates around ${\bar{\theta }}_{\mathrm{QCD}}\sim 10^{-12}$, within reach of the proton storage ring electric dipole moment experiment. The 1 Hz axion is also in reach of near future laboratory and astrophysical searches.

    hep-phastro-ph.COhep-exhep-thJHEP(2021)·33 citations
15. 15*

    Atomic responses to general dark matter-electron interactions

    Riccardo Catena🇸🇪 · Timon Emken🇸🇪 · Nicola A. Spaldin🇨🇭 · Walter Tarantino🇨🇭

    In the leading paradigm of modern cosmology, about 80% of our Universe's matter content is in the form of hypothetical, as yet undetected particles. These do not emit or absorb radiation at any observable wavelengths, and therefore constitute the so-called Dark Matter (DM) component of the Universe. Detecting the particles forming the Milky Way DM component is one of the main challenges for astroparticle physics and basic science in general. One promising way to achieve this goal is to search for rare DM-electron interactions in low-background deep underground detectors. Key to the interpretation of this search is the response of detectors' materials to elementary DM-electron interactions defined in terms of electron wave functions' overlap integrals. In this work, we compute the response of atomic argon and xenon targets used in operating DM search experiments to general, so far unexplored DM-electron interactions. We find that the rate at which atoms can be ionized via DM-electron scattering can in general be expressed in terms of four independent atomic responses, three of which we identify here for the first time. We find our new atomic responses to be numerically important in a variety of cases, which we identify and investigate thoroughly using effective theory methods. We then use our atomic responses to set 90% confidence level (C.L.) exclusion limits on the strength of a wide range of DM-electron interactions from the null result of DM search experiments using argon and xenon targets.

    hep-phastro-ph.COPRResearch(2020)·159 citations
16. 16*

    Search for Long-Lived Heavy Neutrinos at the LHC with a VBF Trigger

    J. Jones-Pérez🇵🇪 · J. Masias🇵🇪 · J. D. Ruiz-Álvarez🇨🇴

    The charged current production of long-lived heavy neutrinos at the LHC can use a prompt charged lepton for triggering the measurement of the process. However, in order to fully characterize the heavy neutrino interactions, it is necessary to also probe Higgs or $Z$ mediated neutral current production. In this case the charged lepton is not available, so other means of triggering are required. In this work, we explore the possibility of using a vector boson fusion trigger in the context of a GeV-scale Type I Seesaw model. We consider a minimal model, where both Higgs and Z-mediated contributions produce one heavy neutrino, as well as an extended model where the Higgs can decay into two heavy ones. Both scenarios are tested through displaced dilepton and displaced multitrack jet searches.

    hep-phEPJC(2020)·46 citations
17. 17*

    NLO Massive Event-Shape Differential and Cumulative Distributions

    Christopher Lepenik🇦🇹 · Vicent Mateu🇪🇸

    We provide a general method to effectively compute differential and cumulative event-shape distributions to $\mathcal{O}({\alpha }_s)$ precision for massive quarks produced primarily at an $e^{+}{e}^{-}$ collider. In particular, we show that at this order, due to the screening of collinear singularities by the quark mass, for all event shapes linearly sensitive to soft dynamics, there appear only two distributions at threshold: a Dirac delta function and a plus distribution. Furthermore, we show that the coefficient of the latter is universal for any infra-red and collinear safe event shape, and provide an analytic expression for it. Likewise, we compute a general formula for the coefficient of the Dirac delta function, which depends only on the event-shape measurement function in the soft limit. Finally, we present an efficient algorithm to compute the differential and cumulative distributions, which does not rely on Monte Carlo methods, therefore achieving a priory arbitrary precision even in the extreme dijet region. We implement this algorithm in a numeric code and show that it agrees with analytic results on the distribution for 2-jettiness, heavy jet mass and a massive generalization of C-parameter.

    hep-phJHEP(2020)·18 citations
18. 18*

    Shining Light on the Scotogenic Model: Interplay of Colliders and Cosmology

    Sven Baumholzer🇩🇪 · Vedran Brdar🇩🇪 · Pedro Schwaller🇩🇪 · Alexander Segner🇩🇪

    In the framework of the scotogenic model, which features radiative generation of neutrino masses, we explore light dark matter scenario. Throughout the paper we chiefly focus on keV-scale dark matter which can be produced either via freeze-in through the decays of the new scalars, or from the decays of next-to-lightest fermionic particle in the spectrum, which is produced through freeze-out. The latter mechanism is required to be suppressed as it typically produces a hot dark matter component. Constraints from BBN are also considered and in combination with the former production mechanism they impose the dark matter to be light. For this scenario we consider signatures at High Luminosity LHC and proposed future hadron and lepton colliders, namely FCC-hh and CLIC, focusing on searches with two leptons and missing energy as a final state. While a potential discovery at High Luminosity LHC is in tension with limits from cosmology, the situation greatly improves for future colliders.

    hep-phastro-ph.COJHEP(2020)·60 citations
19. 19*

    Parity-Violating Møller Scattering at NNLO: Closed Fermion Loops

    Yong Du🇺🇸 · Ayres Freitas🇺🇸 · Hiren H. Patel🇺🇸 · Michael J. Ramsey-Musolf🇺🇸

    A complete, gauge-invariant computation of two loop virtual corrections involving closed fermion loops to the polarized Møller scattering asymmetry is presented. The set of contributions involving two closed fermion loops and the set involving one closed fermion loop are numerically similar in magnitude to the one-loop bosonic corrections and yield an overall correction of 1.3% relative to the tree-level asymmetry. We estimate sizes of remaining two-loop contributions and discuss implications for the upcoming MOLLER experiment.

    hep-phhep-exPRL(2021)·17 citations
20. 20*

    Flavor physics and CP violation

    M.I.Vysotsky🇷🇺

    Lectures at the 53rd Winter School of Petersburg Nuclear Physics Institute and European School on High Energy Physics ESHEP2019, Saint-Petersburg, Russia.

    hep-phhep-exCERN Yellow Rep.School Proc.(2022)·1 citation
21. 21*

    Exclusive hadronic tau decays as probes of non-SM interactions

    Sergi Gonzàlez-Solís🇺🇸 · Alejandro Miranda🇲🇽 · Javier Rendón🇲🇽 · Pablo Roig🇲🇽

    We perform a global analysis of exclusive hadronic tau decays into one and two mesons using the low-energy limit of the Standard Model Effective Field Theory up to dimension six, assuming left-handed neutrinos. A controlled theoretical input on the Standard Model hadronic form factors, based on chiral symmetry, dispersion relations, data and asymptotic QCD properties, has allowed us to set bounds on the New Physics effective couplings using the present experimental data. Our results highlight the importance of semileptonic $\tau$ decays in complementing the traditional low-energy probes, such nuclear $\beta$ decays or semileptonic pion and kaon decays, and the high-energy measurements at LHC scales. This makes yet another reason for considering hadronic tau decays as golden modes at Belle-II.

    hep-phhep-exPLB(2020)·48 citations
22. 22*

    Unified model of nucleon elastic form factors and implications for neutrino-oscillation experiments

    Xilin Zhang🇺🇸 · T. J. Hobbs🇺🇸 · Gerald A. Miller🇺🇸

    Precise knowledge of the nucleon's axial-current form factors is crucial for modeling GeV-scale neutrino-nucleus interactions. Unfortunately, the axial form factor remains insufficiently constrained to meet the precision requirements of upcoming long-baseline neutrino-oscillation experiments. This work studies the nucleon's axial and vector form factors using the light-front approach to build a quark-diquark model of the nucleon with an explicit pion cloud. The light-front wave functions in both the quark and pion-baryon Fock spaces are first calibrated to existing experimental information on the nucleon's electromagnetic form factors, and then used to predict the axial form factor. The resulting squared charge radius of the axial pseudo-vector form factor is predicted to be $r_A^2=0.29\pm 0.03{\mathrm{fm}}^2$, where the small error accounts for the model's parametric uncertainty. We use our form factor results to explore the (quasi-)elastic scattering of neutrinos by (nuclei)nucleons, with the result that the the widely-implemented dipole ansatz is an inadequate approximation of the full form factor for modeling both processes. The approximation leads to a $5-10\%$ over-estimation of the total cross section, depending on the (anti)neutrino energy. We project over-estimations of similar size in the flux-averaged cross sections for the upcoming DUNE long-baseline neutrino-oscillation experiment.

    ↳ nucl-thhep-exhep-lathep-phPRD(2020)·9 citations
23. 23*

    Anomalous transport independent of gauge fields

    Mamiya Kawaguchi🇨🇳 · Ken Kikuchi🇨🇳

    We show that three-dimensional trace anomalies lead to new universal anomalous transport effects on a conformally-flat spacetime with background scalar fields. In contrast to conventional anomalous transports in quantum chromodynamics (QCD) or quantum electrodynamics (QED), our current is independent of background gauge fields. Therefore, our anomalous transport survives even in the absence of vector-like external sources. By manipulating background fields, we suggest a setup to detect our anomalous transport. If one turns on scalar couplings in a finite interval and considers a conformal factor depending just on (conformal) time, we find anomalous transport localized at the interfaces of the interval flows perpendicularly to the interval. The magnitude of the currents is the same on the two interfaces but with opposite directions. Without the assumption on scalar couplings, and only assuming the conformal factor depending solely on (conformal) time as usually done in cosmology, one also finds the three-dimensional Hubble parameter naturally appears in our current.

    ↳ hep-thcond-mat.mes-hallgr-qchep-phPRResearch(2020)·0 citations
24. 24*

    Enhanced $\mathcal{P},\mathcal{T}$-violating nuclear magnetic quadrupole moment effects in laser-coolable molecules

    Malika Denis🇳🇱 · Yongliang Hao🇳🇱 · Ephraim Eliav🇮🇱 · Nicholas R. Hutzler🇺🇸 · Malaya K. Nayak🇮🇳 · Rob G. E. Timmermans🇳🇱 · Anastasia Borschesvky🇳🇱

    Nuclear magnetic quadrupole moments (MQMs), like intrinsic electric dipole moments of elementary particles, violate both parity and time-reversal symmetry and therefore probe physics beyond the Standard Model of particle physics. We report on accurate relativistic coupled cluster calculations of the nuclear MQM interaction constants in BaF, YbF, BaOH, and YbOH. We elaborate on estimates of the uncertainty of our results. The implications of experiments searching for nonzero nuclear MQMs are discussed.

    ↳ physics.atom-phhep-phJ.Chem.Phys.(2020)·42 citations
25. 25*

    New Kähler invariant Fayet-Iliopoulos terms in supergravity and cosmological applications

    Ignatios Antoniadis🇫🇷 · François Rondeau🇫🇷

    Recently, a new type of constant Fayet-Iliopoulos (FI) terms was introduced in $\mathcal{N}=1$ supergravity, which do not require the gauging of the $R$-symmetry. We revisit and generalise these constructions, building a new class of Kähler invariant FI terms parametrised by a function of the gravitino mass as functional of the chiral superfields, which is then used to describe new models of inflation. They are based on a no-scale supergravity model of the inflaton chiral multiplet, supplemented by an abelian vector multiplet with the new FI-term. We show that the inflaton potential is compatible with the CMB observational data, with a vacuum energy at the minimum that can be tuned to a tiny positive value. Finally, the axionic shift symmetry can be gauged by the $U(1)$ which becomes massive. These models offer a mechanism for fixing the gravitino mass in no-scale supergravities, that corresponds to a flat direction of the scalar potential in the absence of the new FI-term; its origin in string theory is an interesting open problem.

    ↳ hep-thhep-phEPJC(2020)·22 citations
26. 26*

    Effect of Electromagnetic Interaction on Galactic Center Flare Components

    Arman Tursunov🇩🇪 · Michal Zajaček🇵🇱 · Andreas Eckart🇩🇪 · Martin Kološ🇨🇿 · Silke Britzen🇩🇪 · Zdeněk Stuchlík🇨🇿 · Bozena Czerny🇵🇱 · Vladimír Karas🇨🇿

    Recently, near-infrared GRAVITY@ESO observations at $2.2\mu \mathrm{m}$ have announced the detection of three bright "flares" in the vicinity of the Galactic center supermassive black hole (SMBH) that exhibited orbital motion at a distance of about $6-11$ gravitational radii from an $\sim 4\times 10^6{M}_{\odot }$ black hole. There are indications of the presence of a large-scale, organized component of the magnetic field at the Galactic center. Electromagnetic effects on the flare dynamics were previously not taken into account despite the relativistic motion of a plasma in magnetic field leading to the charge separation and nonnegligible net charge density in the plasma. Applying various approaches, we find the net charge number density of the flare components of the order of $10^{-3}-10^{-4}$ cm${}^{-3}$, while the particles' total number density is of the order of $10^6-10^8$ cm${}^{-3}$. However, even such a tiny excess of charged particles in the quasi-neutral plasma can significantly affect the dynamics of flare components, which can then lead to the degeneracy in the measurements of spin of the SMBH. Analyzing the dynamics of recent flares in the case of the rapidly rotating black hole, we also constrain the inclination angle between the magnetic field and spin axis to $\alpha <50^{\circ }$, as for larger angles, the motion of the hot spot is strongly chaotic.

    ↳ astro-ph.GAastro-ph.HEgr-qchep-phApJ(2020)·47 citations
27. 27*

    Cosmological Parameters and Neutrino Masses from the Final Planck and Full-Shape BOSS Data

    Mikhail M. Ivanov🇺🇸 · Marko Simonović🇨🇭 · Matias Zaldarriaga🇺🇸

    We present a joint analysis of the Planck cosmic microwave background (CMB) and Baryon Oscillation Spectroscopic Survey (BOSS) final data releases. A key novelty of our study is the use of a new full-shape (FS) likelihood for the redshift-space galaxy power spectrum of the BOSS data, based on an improved perturbation theory template. We show that the addition of the redshift space galaxy clustering measurements breaks degeneracies present in the CMB data alone and tightens constraints on cosmological parameters. Assuming the minimal $\Lambda$CDM cosmology with massive neutrinos, we find the following late-Universe parameters: the Hubble constant \mbox{$H_0=67.95_{-0.52}^{+0.66}$ km s${}^{-1}$Mpc${}^{-1}$}, the matter density fraction \mbox{${\Omega }_m=0.3079_{-0.0085}^{+0.0065}$}, the mass fluctuation amplitude \mbox{${\sigma }_8=0.8087_{-0.0072}^{+0.012}$}, and an upper limit on the sum of neutrino masses \mbox{$M_{\text{tot}}<0.16$ eV} ($95\%$ CL).This can be contrasted with the Planck-only measurements: \mbox{$H_0=67.14_{-0.72}^{+1.3}$} km s${}^{-1}$Mpc${}^{-1}$, ${\Omega }_m=0.3188_{-0.016}^{+0.0091}$, \mbox{${\sigma }_8=0.8053_{-0.0091}^{+0.019}$}, and \mbox{$M_{\text{tot}}<0.26$ eV} ($95\%$ CL). Our bound on the sum of neutrino masses relaxes once the hierarchy-dependent priors from the oscillation experiments are imposed. The addition of the new FS likelihood also constrains the effective number of extra relativistic degrees of freedom, \mbox{$N_{\text{eff}}=2.88\pm 0.17$}. Our study shows that the current FS and the pure baryon acoustic oscillation data add a similar amount of information in combination with the Planck likelihood. We argue that this is just a coincidence given the BOSS volume and efficiency of the current reconstruction algorithms.In the era of future surveys FS will play a dominant role in cosmological parameter measurements.

    ↳ astro-ph.COhep-phPRD(2020)·192 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.