Fri·Mar 12, 2021Friday·March 12, 2021

1. 01*

   Probing CP Violation in Photon Self-Interactions with Cavities

   Marco Gorghetto🇮🇱 · Gilad Perez🇮🇱 · Inbar Savoray🇮🇱 · Yotam Soreq🇮🇱

   In this paper we study CP violation in photon self-interactions at low energy. These interactions, mediated by the effective operator $FFF\tilde{F}$, where ($\tilde{F}$) $F$ is the (dual) electromagnetic field strength, have yet to be directly probed experimentally. Possible sources for such interactions are weakly coupled light scalars with both scalar and pseudoscalar couplings to photons (for instance, complex Higgs-portal scalars or the relaxion), or new light fermions coupled to photons via dipole operators. We propose a method to isolate the CP-violating contribution to the photon self-interactions using Superconducting Radio-Frequency cavities and vacuum birefringence experiments. In addition, we consider several theoretical and experimental indirect bounds on the scale of new physics associated with the above effective operator, and present projections for the sensitivity of the proposed experiments to this scale. We also discuss the implications of these bounds on the CP-violating couplings of new light particles coupled to photons.

   hep-phhep-exJHEP(2021)·13 citations
2. 02*

   Empirical determinations of Feynman integrals using integer relation algorithms

   Kevin Acres · David Broadhurst🇬🇧

   Integer relation algorithms can convert numerical results for Feynman integrals to exact evaluations, when one has reason to suspect the existence of reductions to linear combinations of a basis, with rational or algebraic coefficients. Once a tentative reduction is obtained, confidence in its validity is greatly increased by computing more decimal digits of the terms and verifying the stability of the result. Here we give examples of how the PSLQ and LLL algorithms have yielded remarkable reductions of Feynman integrals to multiple polylogarithms and to the periods and quasi-periods of modular forms. Moreover, these algorithms have revealed quadratic relations between Feynman integrals. A recent application concerning black holes involves quadratic relations between combinations of Feynman integrals with algebraic coefficients.

   hep-phmath.NT6 citations
3. 03*

   Charmonium Properties Using the Discrete Variable Representation (DVR) Method

   Bhaghyesh

   The Schrödinger equation is solved numerically for charmonium using the discrete variable representation (DVR) method. The Hamiltonian matrix is constructed and diagonalized to obtain the eigenvalues and eigenfunctions. Using these eigenvalues and eigenfunctions, spectra and various decay widths are calculated. The obtained results are in good agreement with other numerical methods and with experiments.

   hep-phAdv.High Energy Phys.(2021)·9 citations
4. 04*

   Monte Carlo Scattering-by-Scattering Simulation of 3-Dimensional Elastic WIMP-Nucleus Scattering Events

   Chung-Lin Shan🇹🇼

   In this paper, as the first part of the third step of our study on developing data analysis procedures for using 3-dimensional information offered by directional direct Dark Matter detection experiments in the future, we present our double-Monte Carlo "scattering-by-scattering" simulation of the 3-dimensional elastic WIMP-nucleus scattering process, which can provide 3-D velocity information (the magnitude, the direction, and the incoming/scattering time) of each incident halo WIMP as well as the recoil direction and the recoil energy of the scattered target nucleus in different celestial coordinate systems. For readers' reference, (animated) simulation plots with different WIMP masses and several frequently used target nuclei for all functionable underground laboratories can be found and downloaded on our online (interactive) demonstration webpage (http://www.tir.tw/phys/hep/dm/amidas-2d/).

   hep-phastro-ph.IM7 citations
5. 05*

   Simulations of the Angular Recoil-Energy Distribution of WIMP-Scattered Target Nuclei for Directional Dark Matter Detection Experiments

   Chung-Lin Shan🇹🇼

   In this paper, as the second part of the third step of our study on developing data analysis procedures for using 3-dimensional information offered by directional direct Dark Matter detection experiments in the future, we investigate the angular distributions of the recoil direction (flux) and the recoil energy of the Monte Carlo simulated WIMP-scattered target nuclei observed in different celestial coordinate systems. The "anisotropy" and the "directionality" ("annual" modulation) of the angular recoil-direction/energy distributions will be demonstrated. We will also discuss their dependences on the target nucleus and on the mass of incident halo WIMPs. For readers' reference, all simulation plots presented in this paper (and more) can be found "in animation" on our online (interactive) demonstration webpage (http://www.tir.tw/phys/hep/dm/amidas-2d/).

   hep-phastro-ph.HE6 citations
6. 06*

   Dynamical grooming meets LHC data

   Paul Caucal🇫🇷 · Alba Soto-Ontoso🇫🇷 · Adam Takacs🇳🇴

   In this work, we analyse the all-orders resummation structure of the momentum sharing fraction, $z_g$, opening angle, ${\theta }_g$, and relative transverse momentum, $k_{t,g}$, of the splitting tagged by the dynamical grooming procedure in hadronic collisions. We demonstrate that their resummation does non-exponentiate and it is free of clustering logarithms. Then, we analytically compute the probability distributions of ($z_g$, ${\theta }_g$, $k_{t,g}$) up to next-to next-to-double logarithm accuracy (N2DL) in the narrow jet limit, including a matching to leading order in ${\alpha }_s$. On the phenomenological side, we perform an analytic-to-parton level comparison with Pythia and Herwig. We find that differences between the analytic and the Monte-Carlo results are dominated by the infra-red regulator of the parton shower. Further, we present the first analytic comparison to preliminary ALICE data and highlight the role of non-perturbative corrections in such low-$p_t$ regime. Once the analytic result is corrected by a phenomenologically determined non-perturbative factor, we find very good agreement with the data.

   hep-phhep-exJHEP(2021)·23 citations
7. 07*

   Constraints on Theoretical Predictions Beyond the Standard Model from the Casimir Effect and Some Other Tabletop Physics

   G. L. Klimchitskaya🇷🇺

   We review the hypothetical interactions predicted beyond the Standard Model which could be constrained by using the results of tabletop laboratory experiments. These interactions are described by the power-type potentials with different powers, Yukawa potential, other spin-independent potentials, and by the spin-dependent potentials of different kinds. In all these cases the current constraints on respective hypothetical interactions are considered which follow from the Casimir effect and some other tabletop physics. The exotic particles and constraints on them are discussed in the context of problems of the quantum vacuum, dark energy, and the cosmological constant.

   hep-phUniverse(2021)·13 citations
8. 08*

   Bump Hunting in Latent Space

   Blaž Bortolato🇸🇮 · Barry M. Dillon🇩🇪 · Jernej F. Kamenik🇸🇮 · Aleks Smolkovič🇸🇮

   Unsupervised anomaly detection could be crucial in future analyses searching for rare phenomena in large datasets, as for example collected at the LHC. To this end, we introduce a physics inspired variational autoencoder (VAE) architecture which performs competitively and robustly on the LHC Olympics Machine Learning Challenge datasets. We demonstrate how embedding some physical observables directly into the VAE latent space, while at the same time keeping the classifier manifestly agnostic to them, can help to identify and characterise features in measured spectra as caused by the presence of anomalies in a dataset.

   hep-phcs.LGhep-exPRD(2022)·61 citations
9. 09*

   The Debye Length and the Running Coupling of QCD: a Potential and Phenomenological Approach

   S. D. Campos (Federal University of São Carlos, Brazil)🇧🇷

   In this paper, one uses a damped potential to present a description of the running coupling constant of QCD in the confinement phase. Based on a phenomenological perspective for the Debye screening length, one compares the running coupling obtained here with both the Brodsky-de Téramond-Deur and the Richardson approaches. The results seem to indicate the model introduced here corroborate the Richardson approach. Moreover, the Debye screening mass in the confinement phase depends on a small parameter, which tends to vanish in the non-confinement phase of QCD.

   hep-phhep-lathep-thInt.J.Mod.Phys.A(2021)·1 citation
10. 10*

    Least-Informative Priors for $0\nu \beta \beta$ Decay Searches

    Frank F. Deppisch🇬🇧 · Graham Van Goffrier🇬🇧

    Bayesian parameter inference techniques require a choice of prior distribution which can strongly impact the statistical conclusions drawn. We discuss the construction of least-informative priors for neutrinoless double beta decay searches. Such priors attempt to be objective by maximizing the information gain from an experimental setup. In a parametrization using the lightest neutrino mass $m_l$ and an effective Majorana phase parameter $\Phi$, we construct such a prior using two different approaches and compare them with the standard flat and logarithmic priors in $m_l$.

    hep-phPRD(2021)·2 citations
11. 11*

    From local to nonlocal: higher fidelity simulations of photon emission in intense laser pulses

    T. G. Blackburn🇸🇪 · A. J. MacLeod🇬🇧 · B. King🇬🇧

    State-of-the-art numerical simulations of quantum electrodynamical (QED) processes in strong laser fields rely on a semiclassical combination of classical equations of motion and QED rates, which are calculated in the locally constant field approximation. However, the latter approximation is unreliable if the amplitude of the fields, $a_0$, is comparable to unity. Furthermore, it cannot, by definition, capture interference effects that give rise to harmonic structure. Here we present an alternative numerical approach, which resolves these two issues by combining cycle-averaged equations of motion and QED rates calculated in the locally monochromatic approximation. We demonstrate that it significantly improves the accuracy of simulations of photon emission across the full range of photon energies and laser intensities, in plane-wave, chirped and focused background fields.

    hep-phphysics.opticsphysics.plasm-phNew J.Phys.(2021)·36 citations
12. 12*

    Positronium: an illustration of nonperturbative renormalization in a basis light-front approach

    Xingbo Zhao🇨🇳 · Kaiyu Fu🇨🇳 · Hengfei Zhao🇨🇳 · James P. Vary🇺🇸

    We calculate the mass spectrum and the structure of the positronium system at a strong coupling in a basis light-front approach. We start from the light-front QED Hamiltonian and retain one dynamical photon in our basis. We perform the fermion mass renormalization associated with the nonperturbative fermion self-energy correction. We present the resulting mass spectrum and wave functions for the selected low-lying states. Next, we apply this approach to QCD and calculate the heavy meson system with one dynamical gluon retained. We illustrate the obtained mass spectrum and wave functions for the selected low-lying states.

    hep-phnucl-thPoS(2020)·14 citations
13. 13*

    Expectation management

    Johannes Braathen🇩🇪 · Mark D. Goodsell🇫🇷 · Sebastian Paßehr🇩🇪 · Emanuelle Pinsard🇫🇷

    We consider the application of a Fleischer$-$Jegerlehner-like treatment of tadpoles to the calculation of neutral scalar masses (including the Higgs) in general theories beyond the Standard Model. This is especially useful when the theory contains new scalars associated with a small expectation value, but comes with its own disadvantages. We show that these can be overcome by combining with effective field theory matching. We provide the formalism in this modified approach for matching the quartic coupling of the Higgs via pole masses at one loop, and apply it to both a toy model and to the $\mu$NMSSM as prototypes where the standard treatment can break down.

    hep-phEPJC(2021)·9 citations
14. 14*

    Family Non-Universal U(1)${}^{\prime }$ Model with Minimal Number of Exotics

    Yaşar Hiçyılmaz🇬🇧 · Stefano Moretti🇬🇧 · Levent Solmaz🇹🇷

    We have studied phenomenological implications of several family non-universal U(1)${}^{\prime }$ sub-models in the U(1)${}^{\prime }$-extended Minimal Supersysmmetric Standard Model (UMSSM) possesing an extra down quark type exotic field. In doing this, we have started by enforcing anomaly cancellation criteria to generate a number of solutions in which the extra U(1)${}^{\prime }$ charges of the particles are treated as free parameters. We have then imposed existing bounds coming from colliders and astrophysical observations on the assumed sub-models and observed that current limits dictate certain charge orientations, for instance, $Q_{H_u}\sim Q_{H_d}$ is preferred in general and the charge of the singlet $Q_S$ cannot be very small ($|Q_S|>$ 0.4) even if any of the charges is allowed to take any value within the $[-1,1]$ range. We have finally studied the potential impact of such non-universal charges on $Z^{\prime }$ mediated processes and made predictions for existing and future experiments. It has turned out that UMSSMs with or without the presence of light exotic quarks can yield distinguisable signatures if non-universal charges are realised in the leptonic sector of such models.

    hep-phNPB(2021)·2 citations
15. 15*

    $P_c(4312{)}^{+}$, $P_c(4380{)}^{+}$, and $P_c(4457{)}^{+}$ as double triangle cusps

    Satoshi X. Nakamura (Univ. of Science and Technology of China)🇨🇳

    Understanding the nature of the hidden charm pentaquark(like) signals in the LHCb data for ${\Lambda }_b^0\to J/\psi p{K}^{-}$ is a central problem of hadron spectroscopy. We propose a scenario completely different from previous ones such as hadron molecules and compact pentaquarks. We identify relevant double triangle mechanisms with leading or lower-order singularities. The associated anomalous threshold cusps at the ${\Sigma }_c^{(\ast )}{\bar{D}}^{(\ast )}$ thresholds are significantly more singular than the ordinary ones. Then we demonstrate that the double triangle amplitudes reproduce the peak structures of $P_c(4312{)}^{+}$, $P_c(4380{)}^{+}$, and $P_c(4457{)}^{+}$ in the LHCb data, through an interference with other common mechanisms. Only the $P_c(4440{)}^{+}$ peak is due to a resonance with width and strength significantly smaller than previously estimated. $P_c^{+}$ signals are expected in other processes and the proposed model (partly) explains the current data such as: the GlueX $J/\psi$ photoproduction data with no $P_c^{+}$ signals; the LHCb ${\Lambda }_b^0\to J/\psi p{\pi }^{-}$ data with a possible signal only from $P_c(4440{)}^{+}$. The double triangle singularity is now a possible option to interpret resonancelike structures near thresholds in general.

    hep-phhep-exnucl-thPRD(2021)·66 citations
16. 16*

    New constraints on radiative seesaw models from IceCube and other neutrino detectors

    T. de Boer🇩🇪 · R. Busse🇩🇪 · A. Kappes🇩🇪 · M. Klasen🇩🇪 · S. Zeinstra🇩🇪

    Dark matter (DM) scattering and its subsequent capture in the Sun can boost the local relic density, leading to an enhanced neutrino flux from DM annihilations that is in principle detectable at neutrino telescopes. We calculate the event rates expected for a radiative seesaw model containing both scalar triplet and singlet-doublet fermion DM candidates. In the case of scalar DM, the absence of a spin dependent scattering on nuclei results in a low capture rate in the Sun, which is reflected in an event rate of less than one per year in the current IceCube configuration with 86 strings. For singlet-doublet fermion DM, there is a spin dependent scattering process next to the spin independent one, which significantly boosts the event rate and thus makes indirect detection competitive with respect to the direct detection limits imposed by PICO-60. Due to a correlation between both scattering processes, the limits on the spin independent cross section set by XENON1T exclude also parts of the parameter space that can be probed at IceCube. Previously obtained limits by ANTARES, IceCube and Super-Kamiokande from the Sun and the Galactic Center are shown to be much weaker.

    hep-phastro-ph.HEhep-exPRD(2021)·5 citations
17. 17*

    Signatures of Moat Regimes in Heavy-Ion Collisions

    Robert D. Pisarski🇺🇸 · Fabian Rennecke🇺🇸

    Heavy-ion collisions at small beam energies have the potential to reveal the rich phase structure of QCD at nonzero temperature and density. Among the possible phases are regimes which feature periodic modulations of the spatial structure, where the energy spectrum is shaped like a moat, with the minimum of the energy over a sphere at nonzero momentum. We argue that if the matter created in heavy-ion collisions traverses such a regime, it can produce a characteristic momentum dependence of particle number and their correlations. As an explicit example, we consider a quantum pion liquid phase to compute these quantities on the freeze-out surface. These results can serve as a first guideline for a systematic search of spatially modulated phases in heavy-ion collisions.

    hep-phnucl-thPRL(2021)·69 citations
18. 18*

    Dark Matter and Leptogenesis from Gravitational Production

    Nicolás Bernal🇨🇴 · Chee Sheng Fong🇧🇷

    Since the gravitational interaction is universal, any particle that ever existed, if kinematically accessible, has to be produced through her. We explore the possibility that dark matter is generated purely from gravitational scatterings together with heavy Majorana right-handed neutrinos that are long-lived. Their late decay could inject significant entropy into the thermal bath, diluting both the dark matter abundance and the cosmic baryon asymmetry, thereby imposing various constraints on the reheating dynamics. Additionally to the entropy injection, long-lived right-handed neutrinos could also be responsible for generating the baryon asymmetry through leptogenesis, and hence establish some nontrivial relations between the dark matter and the right-handed properties, and the reheating dynamics

    hep-phJCAP(2021)·42 citations
19. 19*

    All-Order Quartic Couplings in Highly Symmetric D-brane-Anti-D-brane Systems

    Ehsan Hatefi🇮🇹 · Per Sundell🇨🇱

    We compute six-point string amplitudes for the scattering of one closed string Ramond-Ramond state, two tachyons, and two gauge fields in the worldvolume of D-brane-anti-D-brane systems in the Type II superstring theories. From the resulting S-matrix elements, we read off the precise form of the couplings, including their exact numerical coefficients, of two tachyons and two gauge fields in the corresponding highly symmetric effective field theory (EFT) Lagrangian in the worldvolume of D-brane-Anti-D-brane to all orders in ${\alpha }^{\prime }$, which modify and complete previous proposals. We verify that the EFT reproduces the infinite collection of stringy gauge field singularities in dual channels. Inspired by interesting similarities between the all-order highly symmetric EFTs and holographic duals of Vasiliev's higher spin gravities à là Nilsson and Vasiliev, we make a proposal for tensionless limits of D-brane-anti-D-brane systems.

    ↳ hep-thgr-qchep-phJHEP(2021)·3 citations
20. 20*

    A strong broadband 21 cm cosmological signal from dark matter spin-flip interactions

    Mansi Dhuria🇮🇳 · Viraj Karambelkar🇺🇸 · Vikram Rentala🇮🇳 · Priyanka Sarmah🇮🇳

    In the standard cosmology, it is believed that there are two relatively weak and distinct band-limited absorption features, with the first absorption minima near 20 MHz ($z\sim 70$) and the other minima at higher frequencies between 50-110 MHz ($z\sim 12-27$) in the global cosmological 21cm signal, which are signatures of collisional gas dynamics in the cosmic dark ages and Lyman-$\alpha$ photons from the first stars at cosmic dawn, respectively. A similar prediction of two distinct band-limited, but stronger, absorption features is expected in models with excess gas cooling, which have been invoked to explain the EDGES signal. In this work, we explore a novel mechanism, where dark matter spin-flip interactions with electrons through a light axial-vector mediator could directly induce a 21cm absorption signal which is characteristically different from either of these. We find generically, that our model predicts a strong, broadband absorption signal extending from frequencies as low as 1.4 MHz ($z\sim 1000$), from early in the cosmic dark ages where no conventional signal is expected, all the way up to higher frequencies where star formation and X-ray heating effects are expected to terminate the absorption signal. In the standard cosmology and in excess gas cooling models it is expected that the gas spin temperature as inferred from the absorption signal is a tracer of the gas kinetic temperature. However, in our model we find in certain regions of parameter space that the spin temperature and kinetic temperature of the gas evolve differently, and the absorption signal only measures the spin temperature evolution. Large swathes of our model parameter space of interest are safe from existing constraints, however future searches for short range spin-dependent forces between electrons on the mm to nm scale have the potential to discover the light mediator responsible for our predicted signal.

    ↳ astro-ph.COhep-phJCAP(2021)·7 citations
21. 21*

    Weinberg's proposal of 1990: A very personal view

    R. Machleidt🇺🇸

    My personal encounter with Weinberg's proposal of 1990 was a really entertaining one: My collaborator David Entem and I had embarked to show that Weinberg's idea, though smart and beautiful, was essentially useless in practice (like so many of those genius ideas of the 1980s where people claimed to have "derived the nuclear force from QCD"). However, in trying to do so, we showed the opposite; namely, we showed that Weinberg's idea worked better than allowed by any reasonable means.

    ↳ nucl-thhep-phnucl-exphysics.hist-phFew Body Syst.(2021)·7 citations
22. 22*

    Measurements of the branching fractions of the semileptonic decays ${\Xi }_c^0\to {\Xi }^{-}{\ell }^{+}{\nu }_{\ell }$ and the asymmetry parameter of ${\Xi }_c^0\to {\Xi }^{-}{\pi }^{+}$

    Belle Collaboration: Y. B. Li🇨🇳 · C. P. Shen🇨🇳 · I. Adachi🇯🇵 · K. Adamczyk🇵🇱 · H. Aihara🇯🇵 · S. Al Said🇸🇦 · D. M. Asner🇺🇸 · T. Aushev🇷🇺 · R. Ayad🇸🇦 · V. Babu🇩🇪 · P. Behera🇮🇳 · J. Bennett🇺🇸 and 172 other authors

    Using data samples of 89.5 and 711 fb${}^{-1}$ recorded at energies of $\sqrt{s}=10.52$ and $10.58$ GeV, respectively, with the Belle detector at the KEKB $e^{+}{e}^{-}$ collider, we report measurements of branching fractions of semileptonic decays ${\Xi }_c^0\to {\Xi }^{-}{\ell }^{+}{\nu }_{\ell }$ ($\ell =e$ or $\mu$) and the $CP$-asymmetry parameter of ${\Xi }_c^0\to {\Xi }^{-}{\pi }^{+}$ decay. The branching fractions are measured to be $\mathcal{B}({\Xi }_c^0\to {\Xi }^{-}{e}^{+}{\nu }_e)=(1.31\pm 0.04\pm 0.07\pm 0.38)\%$ and $\mathcal{B}({\Xi }_c^0\to {\Xi }^{-}{\mu }^{+}{\nu }_{\mu })=(1.27\pm 0.06\pm 0.10\pm 0.37)\%$, and the decay parameter ${\alpha }_{\Xi \pi }$ is measured to be $0.63\pm 0.03\pm 0.01$ with much improved precision compared to the current world average. The corresponding ratio $\mathcal{B}({\Xi }_c^0\to {\Xi }^{-}{e}^{+}{\nu }_e)/\mathcal{B}({\Xi }_c^0\to {\Xi }^{-}{\mu }^{+}{\nu }_{\mu })$ is $1.03\pm 0.05\pm 0.07$, which is consistent with the expectation of lepton flavor universality. The first measured asymmetry parameter ${\mathcal{A}}_{CP}=({\alpha }_{{\Xi }^{-}{\pi }^{+}}+{\alpha }_{{\bar{\Xi }}^{+}{\pi }^{-}})/({\alpha }_{{\Xi }^{-}{\pi }^{+}}-{\alpha }_{{\bar{\Xi }}^{+}{\pi }^{-}})=0.024\pm 0.052\pm 0.014$ is found to be consistent with zero. The first and the second uncertainties above are statistical and systematic, respectively, while the third ones arise due to the uncertainty of the ${\Xi }_c^0\to {\Xi }^{-}{\pi }^{+}$ branching fraction.

    ↳ hep-exhep-phPRL(2021)·71 citations
23. 23*

    Spectral sum of current correlators from lattice QCD

    Tsutomu Ishikawa🇯🇵 · Shoji Hashimoto🇯🇵

    We propose a method to use lattice QCD to compute the Borel transform of the vacuum polarization function appearing in the Shifman-Vainshtein-Zakharov QCD sum rule. We construct the spectral sum corresponding to the Borel transform from two-point functions computed on the Euclidean lattice. As a proof of principle, we compute the $s\bar{s}$ correlators at three lattice spacings and take the continuum limit. We confirm that the method yields results that are consistent with the operator product expansion in the large Borel mass region. The method provides a ground on which the OPE analyses can be directly compared with nonperturbative lattice computations.

    ↳ hep-lathep-phPRD(2021)·5 citations
24. 24*

    A cornucopia of antineutrons and hyperons from super J/psi factory for next-generation nuclear and particle physics high-precision experiments

    Chang-Zheng Yuan🇨🇳 · Marek Karliner🇮🇱

    In order to study the interactions and structure of various types of matter one typically needs to carry out scattering experiments utilizing many different particles as projectiles. Whereas beams of $e^{\pm }$, ${\mu }^{\pm }$, ${\pi }^{\pm }$, $K^{\pm }$, proton, antiproton, and of various heavy ions have been produced and have enabled many scientific breakthroughs, beams of antineutrons, hyperons ($\Lambda$, $\Sigma$ and $\Xi$) and their antiparticles are typically not easy to obtain. Here we point out and investigate a new high-quality source of these particles: a super $J/\psi$ factory with capability of accumulating trillions of $J/\psi$ decays each year. In the relevant $J/\psi$ decays the desired particle is produced together with other final state particles that can be tagged. This allows accurate determination of the flux and momentum of the projectile, enabling unprecedented precision-study of the corresponding interactions with a broad range of targets. These novel high-statistics sources of baryons and antibaryons with precisely known kinematics open fresh opportunities for applications in particle and nuclear physics, including antinucleon-nucleon interaction, nonvalence $s\bar{s}$ component of the nucleon, (anti)hyperon-nucleon interaction, OZI violation, (multi-strange) hypernuclei, exotic light hadron spectroscopy and many others, as well as calibration of Monte Carlo simulation for hadronic and medical physics.

    ↳ hep-exhep-phnucl-exnucl-thPRL(2021)·41 citations
25. 25*

    Searching for parity violation with the LIGO-Virgo-KAGRA network

    Katarina Martinovic🇬🇧 · Charles Badger🇬🇧 · Mairi Sakellariadou🇬🇧 · Vuk Mandic🇺🇸

    A stochastic gravitational wave background is expected to emerge from the superposition of numerous gravitational wave sources of both astrophysical and cosmological origin. A number of cosmological models can have a parity violation, resulting in the generation of circularly polarised gravitational waves. We present a method to search for parity violation in the gravitational wave data. We first apply this method to the most recent, third, LIGO-Virgo observing run. We then investigate the constraining power of future A+ LIGO-Virgo detectors, including KAGRA to the network, for a gravitational wave background generated by early universe cosmological turbulence.

    ↳ gr-qchep-phPRD(2021)·41 citations
26. 26*

    The Coulomb branch of N=4 SYM and dilatonic scions in supergravity

    Daniel Elander🇫🇷 · Maurizio Piai🇬🇧 · John Roughley🇬🇧

    We find a parametrically light dilaton in special confining theories in three dimensions. Their duals form what we call a scion of solutions to the supergravity associated with the large-N limit of the Coulomb branch of the N=4 Super-Yang-Mills (SYM) theory. The supergravity description contains one scalar with bulk mass that saturates the Breitenlohner-Freedman unitarity bound. The new solutions are defined within supergravity, they break supersymmetry and scale invariance, and one dimension is compactified on a shrinking circle, yet they are completely regular. An approximate dilaton appears in the spectrum of background fluctuations (or composite states in the confining theory), and becomes parametrically light along a metastable portion of the scion of new supergravity solutions, in close proximity of a tachyonic instability. A first-order phase transition separates stable backgrounds, for which the approximate dilaton is not parametrically light, from metastable and unstable backgrounds, for which the dilaton becomes parametrically light, and eventually tachyonic.

    ↳ hep-thhep-lathep-phPRD(2021)·20 citations
27. 27*

    Monte Carlo evaluation of the continuum limit of the two-point function of the Euclidean free real scalar field subject to affine quantization

    Riccardo Fantoni · John R. Klauder

    We study canonical and affine versions of the quantized covariant Euclidean free real scalar field-theory on four dimensional lattices through the Monte Carlo method. We calculate the two-point function at small values of the bare coupling constant and near the continuum limit at finite volume. Our investigation shows that affine quantization is able to give meaningful results for the two-point function for which is not available an exact analytic result and therefore numerical methods are necessary.

    ↳ hep-lathep-phhep-thphysics.comp-ph+1J. Stat. Phys. 184, 28 (2021)
28. 28*

    Ab initio computation of the longitudinal response function in ${}^{40}$Ca

    J. E. Sobczyk🇩🇪 · B. Acharya🇩🇪 · S. Bacca🇩🇪 · G. Hagen🇺🇸

    We present a consistent \emph{ab initio} computation of the longitudinal response function $R_L$ in ${}^{40}$Ca using the coupled-cluster and Lorentz integral transform methods starting from chiral nucleon-nucleon and three-nucleon interactions. We validate our approach by comparing our results for $R_L$ in ${}^4$He and the Coulomb sum rule in ${}^{40}$Ca against experimental data and other calculations. For $R_L$ in ${}^{40}$Ca we obtain a very good agreement with experiment in the quasi-elastic peak up to intermediate momentum transfers, and we find that final state interactions are essential for an accurate description of the data. This work presents a milestone towards \emph{ab initio} computations of neutrino-nucleus cross sections relevant for experimental long-baseline neutrino programs.

    ↳ nucl-thhep-exhep-phnucl-exPRL(2021)·57 citations
29. 29*

    Novel null tests for the spatial curvature and homogeneity of the Universe and their machine learning reconstructions

    Rubén Arjona🇪🇸 · Savvas Nesseris🇪🇸

    A plethora of observational data obtained over the last couple of decades has allowed cosmology to enter into a precision era and has led to the foundation of the standard cosmological constant and cold dark matter paradigm, known as the $\Lambda$CDM model. Given the many possible extensions of this concordance model, we present here several novel consistency tests which could be used to probe for deviations from $\Lambda$CDM. First, we derive a joint consistency test for the spatial curvature ${\Omega }_{k,0}$ and the matter density ${\Omega }_{\text{m,0}}$ parameters, constructed using only the Hubble rate $H(z)$, which can be determined directly from observations. Second, we present a new test of possible deviations from homogeneity using the combination of two datasets, either the baryon acoustic oscillation (BAO) and $H(z)$ data or the transversal and radial BAO data, while we also introduce two consistency tests for $\Lambda$CDM which could be reconstructed via the transversal and radial BAO data. We then reconstruct the aforementioned tests using the currently available data in a model independent manner using a particular machine learning approach, namely the Genetic Algorithms. Finally, we also report on a $\sim 4\sigma$ tension on the transition redshift as determined by the $H(z)$ and radial BAO data.

    ↳ astro-ph.COgr-qchep-phPRD(2021)·55 citations
30. 30*

    Superradiance in String Theory

    Viraf M. Mehta🇩🇪 · Mehmet Demirtas🇺🇸 · Cody Long🇺🇸 · David J. E. Marsh🇬🇧 · Liam McAllister🇺🇸 · Matthew J. Stott🇬🇧

    We perform an extensive analysis of the statistics of axion masses and interactions in compactifications of type IIB string theory, and we show that black hole superradiance excludes some regions of Calabi-Yau moduli space. Regardless of the cosmological model, a theory with an axion whose mass falls in a superradiant band can be probed by the measured properties of astrophysical black holes, unless the axion self-interaction is large enough to disrupt formation of a condensate. We study a large ensemble of compactifications on Calabi-Yau hypersurfaces, with $1\le h^{1,1}\le 491$ closed string axions, and determine whether the superradiance conditions on the masses and self-interactions are fulfilled. The axion mass spectrum is largely determined by the Kähler parameters, for mild assumptions about the contributing instantons, and takes a nearly-universal form when $h^{1,1}\gg 1$. When the Kähler moduli are taken at the tip of the stretched Kähler cone, the fraction of geometries excluded initially grows with $h^{1,1}$, to a maximum of $\approx 0.5$ at $h^{1,1}\approx 160$, and then falls for larger $h^{1,1}$. Further inside the Kähler cone, the superradiance constraints are far weaker, but for $h^{1,1}\gg 100$ the decay constants are so small that these geometries may be in tension with astrophysical bounds, depending on the realization of the Standard Model.

    ↳ hep-thastro-ph.COhep-phJCAP(2021)·175 citations
31. 31*

    3-Dimensional Effective Velocity Distribution of Halo Weakly Interacting Massive Particles Scattering off Nuclei in Direct Dark Matter Detectors

    Chung-Lin Shan🇹🇼

    In this paper, as the third part of the third step of our study on developing data analysis procedures for using 3-dimensional information offered by directional direct Dark Matter detection experiments in the future, we introduce a 3-dimensional effective velocity distribution of halo Weakly Interacting Massive Particles (WIMPs), which, instead of the theoretically prediction of the entire Galactic Dark Matter particles, describes the actual velocity distribution of WIMPs scattering off (specified) target nuclei in an underground detector. Its target and WIMP-mass dependences as well as ("annual" modulations of) its "anisotropy" in the Equatorial/laboratory and even the Galactic coordinate systems will be demonstrated and discussed in detail. For readers' reference, all simulation plots presented in this paper (and more) can be found "in animation" on our online (interactive) demonstration webpage (http://www.tir.tw/phys/hep/dm/amidas-2d/).

    ↳ astro-ph.HEhep-ph4 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.