Thu·Nov 12, 2020Thursday·November 12, 2020

1. 01*

   W-boson production in TMD factorization

   Daniel Gutierrez-Reyes🇪🇸 · Sergio Leal-Gomez🇦🇹 · Ignazio Scimemi🇪🇸

   At hadron colliders, the differential cross section for $W$ production can be factorized and it is sensitive transverse momentum dependent distributions (TMD) for low boson transverse momentum. While, often, the corresponding non-perturbative QCD contributions are extrapolated from $Z$ boson production, here we use an existing extraction (based on the code Artemide) of TMD which includes data coming from Drell-Yan and semi-inclusive deep inelastic scattering, to provide checks and predictions for the $W$ case. Including fiducial cuts with different configurations and kinematical power corrections, we consider transverse momentum dependent cross sections within several intervals of the vector boson transverse mass. We perform the same study for the $p_T^{W^{-}}/p_T^{W^{+}}$ and $p_T^Z/p_T^W$ distributions. We compare our predictions with recent extractions of these quantities at ATLAS and CMS and results from TeVatron. The results encourage a broader experimental and phenomenological work, and a deeper study of TMD for the $W$ case.

   hep-phhep-exnucl-exnucl-thEPJC(2021)·4 citations
2. 02*

   Transient Radio Signatures from Neutron Star Encounters with QCD Axion Miniclusters

   Thomas D. P. Edwards🇸🇪 · Bradley J. Kavanagh🇪🇸 · Luca Visinelli🇳🇱 · Christoph Weniger🇳🇱

   The QCD axion is expected to form dense structures known as axion miniclusters if the Peccei-Quinn symmetry is broken after inflation. Miniclusters that have survived until today will interact with neutron stars (NSs) in the Milky Way to produce transient radio signals from axion-photon conversion in the NS magnetosphere. We quantify the properties of these encounters and find that they occur frequently ($\mathcal{O}(1-100){\mathrm{day}}^{-1}$); last between a day and a few months; are spatially clustered towards the Galactic center; and can reach observable fluxes. These radio transients are within reach of current generation telescopes and therefore offer a promising pathway to discovering QCD axion dark matter.

   hep-phastro-ph.COastro-ph.GAPRL(2021)·89 citations
3. 03*

   Semileptonic Decay of $B_c$ to ${\eta }_c$ and $J/\psi$ on the Light Front

   Shuo Tang🇺🇸 · Shaoyang Jia🇺🇸 · Pieter Maris🇺🇸 · James P. Vary🇺🇸

   We study the semileptonic decay of the $B_c(0^{-})$ to charmonia through the bottom-to-charm-quark electroweak current in the framework of basis light-front quantization. Explicitly, we calculate the weak transition form factors for processes of $B_c$ decaying into ${\eta }_c$ or $J/\psi$ based on the corresponding initial and final valence light-front wave functions both obtained from the basis light-front quantization. We also present the corresponding differential decay width and branching ratios, as well as the branching ratios for decays into the ${\eta }_c^{\prime }$ and the ${\psi }^{\prime }$. We observe unphysical frame dependence of the calculated form factors, which is attributed to only including the valence light-front wave functions. Based on the analysis of current component, we propose a preferred set of frames to calculate these form factors.

   hep-phhep-thPRD(2021)·13 citations
4. 04*

   Neutrino refractive effects during their decoupling era in the early universe

   R. F. Sawyer🇺🇸

   There is an accepted approach to calculation of the neutrino flavor density-matrix in the halo of a supernova, in which neutrino amplitudes, not cross-sections, need to be followed carefully in the region above the region of frequent scatterings. The same reasoning and techniques, applied to the evolution of neutrino flavors and energy distributions in the early universe in the era of neutrino decoupling, leads to radical changes in the prediction of the effects of the neutrino-neutrino interaction. Predictions for the production of sterile neutrinos, should they exist, will also be changed.

   hep-phastro-ph.CO2 citations
5. 05*

   The rainbow modified-ladder approximation and degenerate pion

   Lei Chang🇨🇳 · Minghui Ding🇮🇹

   Correlation functions can be described by the corresponding equations, $viz.$, gap equation for quark propagator and the inhomogeneous Bethe-Salpeter equation for vector dressed-fermion-Abelian-gauge-boson vertex in which specific truncations have to be implemented. The general vector and axial-vector Ward-Green-Takahashi identities require these correlation functions to be interconnected, in consequence of this, truncations made must be controlled consistently. It turns out that if the rainbow approximation is assumed in gap equation, the scattering kernel in Bethe-Salpeter equation can adopt the ladder approximation, which is one of the most basic attempts to truncate the scattering kernel. Additionally, a modified-ladder approximation is also found to be a possible symmetry-preserving truncation scheme. As an illustration of this approximation for application a treatment of pion is included. Pion mass and decay constant are found to be degenerate in ladder and modified-ladder approximations, even though the Bethe-Salpeter amplitude are with apparent distinction. The justification for the modified-ladder approximation is examined with the help of the Gell-Mann-Oakes-Renner (GMOR) relation.

   hep-phPRD(2021)·4 citations
6. 06*

   Effect of sterile neutrino on low energy processes in minimal extended seesaw with $\Delta (96)$ symmetry and ${\text{TM}}_1$ mixing

   Nayana Gautam🇮🇳 · R. Krishnan🇮🇳 · Mrinal Kumar Das🇮🇳

   We study the effect of sterile neutrino on some low scale processes in the framework of minimal extended seesaw (MES). MES is the extension of the seesaw mechanism with the addition of sterile neutrino of intermediate mass. The MES model in this work is based on $\Delta (96)\times C_2\times C_3$ flavor symmetry. The structures of mass matrices in the framework lead to $T{M}_1$ mixing with $\mu \text{-}\tau$ symmetry. The model predicts maximal value of Dirac CP phase. We carry out our analysis to study the new physics contributions from the sterile neutrino to different charged lepton flavor violation (cLFV) processes involving muon and tau leptons as well as neutrinoless double beta decay (0$\nu \beta \beta$). The model predicts normal ordering (NO) of neutrino masses and we perform the numerical analysis considering normal ordering (NO) only. We find that sterile neutrino mass in GeV range can lead to cLFV processes that are within the reach of current and planned experiments. The GeV scale sterile neurtrino in our model is consistent with the current limits on the effective neutrino mass set by $0\nu \beta \beta$ experiments.

   hep-phFront.in Phys.(2021)·4 citations
7. 07*

   Ballistic diffusion of heavy quarks in the early stage of relativistic heavy ion collisions at RHIC and LHC

   Jun-Hong Liu🇨🇳 · Santosh K. Das🇮🇳 · Vincenzo Greco🇮🇹 · Marco Ruggieri🇨🇳

   We study the diffusion of charm quarks in the early stage of high energy nuclear collisions at the RHIC and the LHC. The main novelty of the present study is the introduction of the color current carried by the heavy quarks that propagate in the evolving Glasma (Ev-Glasma), that is responsible of the energy loss via polarization of the medium. We compute the transverse momentum broadening, ${\sigma }_p$, of charm in the pre-thermalization stage, and the impact of the diffusion on the nuclear modification factor in nucleus-nucleus collisions. The net effect of energy loss is marginal in the pre-thermalization stage. The study is completed by the calculation of coordinate spreading, ${\sigma }_x$, and by a comparison with Langevin dynamics. ${\sigma }_p$ in Ev-Glasma overshoots the result of standard Langevin dynamics at the end of the pre-hydro regime. We interpret this as a result of memory of the color force acting on the charm quarks that implies ${\sigma }_p\propto t^2$. Moreover, ${\sigma }_x\propto t^2$ in the pre-hydro stage shows that the charm quark in the Ev-Glasma is in the regime of ballistic diffusion.

   hep-phnucl-thPRD(2021)·34 citations
8. 08*

   Implications of new physics in $B\to K_1{\mu }^{+}{\mu }^{-}$ decay processes

   Aishwarya Bhatta🇮🇳 · Rukmani Mohanta🇮🇳

   In recent times, several discrepancies at the level of $(2-3)\sigma$ have been observed in the decay processes mediated by flavour changing neutral current (FCNC) transitions $b\to s{\ell }^{+}{\ell }^{-}$, which may be considered as the smoking-gun signal of New Physics (NP). These intriguing hints of NP have attracted a lot of attention and many attempts are made to look for the possible NP signature in other related processes, which are mediated through the same quark-level transitions. In this work, we perform a comprehensive analysis of the FCNC decays of $B$ meson to axial vector mesons $K_1(1270)$ and $K_1(1400)$, which are admixture of the $1^3{P}_1$ and $1^1{P}_1$ states $K_{1A}$ and $K_{1B}$, in a model independent framework. Using the $B\to K_1$ form factors evaluated in the light cone sum rule approach, we investigate the rare exclusive semileptonic decays $B\to K_1(1270){\mu }^{+}{\mu }^{-}$ and $B\to K_1(1400){\mu }^{+}{\mu }^{-}$. Considering all the possible relevant operators for $b\to s{\ell }^{+}{\ell }^{-}$ transitions, we study their effects on various observables such as branching fractions, lepton flavor universality violating ratio ($R_{K_1})$, forward-backward asymmetries, and lepton polarization asymmetries of these processes. These results will not only enhance the theoretical understanding of the mixing angle but also serve as a good tool for probing New Physics.

   hep-phJ.Phys.G(2021)·4 citations
9. 09*

   Properties of $P_c(4312)$ pentaquark and its bottom partner

   K. Azizi🇮🇷 · Y. Sarac🇹🇷 · H. Sundu🇹🇷

   We present an analysis of the newly observed pentaquark $P_c(4312{)}^{+}$ to shed light on its quantum numbers. To do that, the QCD sum rule approach is used. The measured mass of this particle is close to ${\Sigma }_c^{++}{\bar{D}}^{-}$ threshold and has a small width, which supports the possibility of its being a molecular state. We consider an interpolating current in a molecular form and analyze both the positive and negative parity states with spin-$\frac{1}{2}$. We also consider the bottom counterpart of the state with similar molecular form. Our mass result for the charm pentaquark state supports that, the quantum numbers of the observed state are consistent with $J^P={\frac{1}{2}}^{-}$.

   hep-phhep-exhep-latCPC(2021)·29 citations
10. 10*

    The measurable angular distribution of ${\Lambda }_b^0\to {\Lambda }_c^{+}(\to {\Lambda }^0{\pi }^{+}){\tau }^{-}(\to {\pi }^{-}{\nu }_{\tau }){\bar{\nu }}_{\tau }$ decay

    Quan-Yi Hu🇨🇳 · Xin-Qiang Li🇨🇳 · Ya-Dong Yang🇨🇳 · Dong-Hui Zheng🇨🇳

    In ${\Lambda }_b^0\to {\Lambda }_c^{+}(\to {\Lambda }^0{\pi }^{+}){\tau }^{-}{\bar{\nu }}_{\tau }$ decay, the solid angle of the final-state particle ${\tau }^{-}$ cannot be determined precisely since the decay products of the ${\tau }^{-}$ include an undetected ${\nu }_{\tau }$. Therefore, the angular distribution of this decay cannot be measured. In this work, we construct a {\it measurable} angular distribution by considering the subsequent decay ${\tau }^{-}\to {\pi }^{-}{\nu }_{\tau }$. The full cascade decay is ${\Lambda }_b^0\to {\Lambda }_c^{+}(\to {\Lambda }^0{\pi }^{+}){\tau }^{-}(\to {\pi }^{-}{\nu }_{\tau }){\bar{\nu }}_{\tau }$. The three-momenta of the final-state particles ${\Lambda }^0$, ${\pi }^{+}$, and ${\pi }^{-}$ can be measured. Considering all Lorentz structures of the new physics (NP) effective operators and an unpolarized initial ${\Lambda }_b$ state, the five-fold differential angular distribution can be expressed in terms of ten angular observables ${\mathcal{K}}_i(q^2,E_{\pi })$. By integrating over some of the five kinematic parameters, we define a number of observables, such as the ${\Lambda }_c$ spin polarization $P_{{\Lambda }_c}(q^2)$ and the forward-backward asymmetry of ${\pi }^{-}$ meson $A_{FB}(q^2)$, both of which can be represented by the angular observables ${\hat{\mathcal{K}}}_i(q^2)$. We provide numerical results for the entire set of the angular observables ${\hat{\mathcal{K}}}_i(q^2)$ and ${\hat{\mathcal{K}}}_i$ both within the Standard Model and in some NP scenarios, which are a variety of best-fit solutions in seven different NP hypotheses. We find that the NP which can resolve the anomalies in $\bar{B}\to D^{(\ast )}{\tau }^{-}{\bar{\nu }}_{\tau }$ decays has obvious effects on the angular observables ${\hat{\mathcal{K}}}_i(q^2)$, except ${\hat{\mathcal{K}}}_{1ss}(q^2)$ and ${\hat{\mathcal{K}}}_{1cc}(q^2)$.

    hep-phJHEP(2021)·29 citations
11. 11*

    Shining Primordial Black Holes

    Mark P. Hertzberg🇺🇸 · Sami Nurmi🇫🇮 · Enrico D. Schiappacasse🇫🇮 · Tsutomu T. Yanagida🇨🇳

    We study the well-motivated mixed dark matter (DM) scenario composed of a dominant thermal WIMP, highlighting the case of $SU(2{)}_L$ triplet fermion "winos", with a small fraction of primordial black holes (PBHs). After the wino kinetic decoupling, the DM particles are captured by PBHs leading to the presence of PBHs with dark minihalos in the Milky Way today. The strongest constraints for the wino DM come from the production of narrow line gamma rays from wino annihilation in the Galactic Center. We analyse in detail the viability of the mixed wino DM scenario, and determine the constraints on the fraction of DM in PBHs assuming a cored halo profile in the Milky Way. We show that already with the sensitivity of current indirect searches, there is a significant probability for detecting a gamma ray signal characteristic for the wino annihilation in a single nearby dressed PBH when $M_{\text{PBH}}\sim M_{\odot }$, which we refer to as a "shining black hole". Similar results should apply also in more general setups with ultracompact minihalos or other DM models, since the accretion of DM around large overdensities and DM annihilation are both quite generic processes.

    hep-phastro-ph.COastro-ph.HEgr-qcPRD(2021)·24 citations
12. 12*

    Flavor-dependent radiative corrections in coherent elastic neutrino-nucleus scattering

    Oleksandr Tomalak🇺🇸 · Pedro Machado🇺🇸 · Vishvas Pandey🇺🇸 · Ryan Plestid🇺🇸

    We calculate coherent elastic neutrino-nucleus scattering cross sections on spin-0 nuclei (e.g. ${}^{40}$Ar and ${}^{28}$Si) at energies below 100 MeV within the Standard Model and account for all effects of permille size. We provide a complete error budget including uncertainties at nuclear, nucleon, hadronic, and quark levels separately as well as perturbative error. Our calculation starts from the four-fermion effective field theory to explicitly separate heavy-particle mediated corrections (which are absorbed by Wilson coefficients) from light-particle contributions. Electrons and muons running in loops introduce a nontrivial dependence on the momentum transfer due to their relatively light masses. These same loops, and those mediated by tau leptons, break the flavor universality because of mass-dependent electromagnetic radiative corrections. Nuclear physics uncertainties significantly cancel in flavor asymmetries resulting in subpercent relative errors. We find that for low neutrino energies, the cross section can be predicted with a relative precision that is competitive with neutrino-electron scattering. We highlight potentially useful applications of such a precise cross section prediction ranging from precision tests of the Standard Model, to searches for new physics and to the monitoring of nuclear reactors.

    hep-phhep-exnucl-exnucl-thJHEP(2021)·90 citations
13. 13*

    Constraints on Axions from Cosmic Distance Measurements

    Manuel A. Buen-Abad🇺🇸 · JiJi Fan🇺🇸 · Chen Sun🇮🇱

    Axion couplings to photons could induce photon-axion conversion in the presence of magnetic fields in the Universe. This conversion could impact various cosmic distance measurements, such as luminosity distances to type Ia supernovae and angular distances to galaxy clusters, in different ways. In this paper we consider different combinations of the most up-to-date distance measurements to constrain the axion-photon coupling. Employing the conservative cell magnetic field model for the magnetic fields in the intergalactic medium (IGM) and ignoring the conversion in the intracluster medium (ICM), we find the upper bounds on axion-photon couplings to be around $5\times 10^{-12}$ (nG/$B$) $\sqrt{Mpc/s}$ GeV${}^{-1}$ for axion masses $m_a$ below $10^{-13}$ eV, where $B$ is the strength of the IGM magnetic field, and $s$ is the comoving size of the magnetic domains. When including the conversion in the ICM, the upper bound is lowered and could reach $5\times 10^{-13}$GeV${}^{-1}$ for $m_a<5\times 10^{-12}$ eV. While this stronger bound depends on the ICM modeling, it is independent of the strength of the IGM magnetic field, for which there is no direct evidence yet. These constraints could be placed on firmer footing with an enhanced understanding and control of the astrophysical uncertainties associated with the IGM and ICM. All the bounds are determined by the shape of the Hubble rate as a function of redshift reconstructable from various distance measurements, and insensitive to today's Hubble rate, of which there is a tension between early and late cosmological measurements. As an appendix, we discuss the model building challenges of the use of photon-axion conversion to make type Ia supernovae brighter to alleviate the Hubble problem/crisis.

    hep-phastro-ph.COJHEP(2022)·36 citations
14. 14*

    Heavy Axion Opportunities at the DUNE Near Detector

    Kevin J. Kelly🇺🇸 · Soubhik Kumar🇺🇸 · Zhen Liu🇺🇸

    While the QCD axion is often considered to be necessarily light ($\lesssim$ eV), recent work has opened a viable and interesting parameter space for heavy axions, which solve both the Strong CP and the axion Quality Problems. These well-motivated heavy axions, as well as the generic axion-like-particles, call for explorations in the GeV mass realm at collider and beam dump environments. The primary upcoming neutrino experiment, Deep Underground Neutrino Experiment (DUNE), is simultaneously also a powerful beam dump experiment, enabled by its multipurpose Near Detector (ND) complex. In this study, we show with detailed analyses that the DUNE ND has a unique sensitivity to heavy axions for masses between $20$ MeV and $2$ GeV, complementary to other future experiments.

    hep-phhep-exPRD(2021)·100 citations
15. 15*

    Spin and Polarization in High-Energy Hadron-Hadron and Lepton-Hadron Scattering

    László Jenkovszky🇺🇦

    The role of spin degrees of freedom in high-energy hadron-hadron and lepton-hadron scattering is reviewed with emphasis on the dominant role of soft, diffractive, non-perturbative effects. Explicit models based on analyticity and Regge-pole theory, including the pomeron trajectory (gluon exchange in the $t$ channel) are discussed. We argue that there is a single, universal pomeron in Nature, manifest as relatively "soft" or "hard", depending on the kinematics considered. Regge trajectories are non-linear, complex functions, predicting a finite number of resonances. Explicit models and fits are presented that may be used in recovering generalized parton distributions from deeply virtual Compton scattering and electoproduction of vector mesons.

    hep-phSymmetry(2020)·6 citations
16. 16*

    Stellar Disruption of Axion Miniclusters in the Milky Way

    Bradley J. Kavanagh🇪🇸 · Thomas D. P. Edwards🇸🇪 · Luca Visinelli🇳🇱 · Christoph Weniger🇳🇱

    Axion miniclusters are dense bound structures of dark matter axions that are predicted to form in the post-inflationary Peccei-Quinn symmetry breaking scenario. Although dense, miniclusters can easily be perturbed or even become unbound by interactions with baryonic objects such as stars. Here, we characterize the spatial distribution and properties of miniclusters in the Milky Way (MW) today after undergoing these stellar interactions throughout their lifetime. We do this by performing a suite of Monte Carlo simulations which track the miniclusters' structure and, in particular, accounts for partial disruption and mass loss through successive interactions. We consider two density profiles - Navarro-Frenk-White (NFW) and Power-law (PL) - for the individual miniclusters in order to bracket the uncertainties on the minicluster population today due to their uncertain formation history. For our fiducial analysis at the Solar position, we find a survival probability of 99% for miniclusters with PL profiles and 46% for those with NFW profiles. Our work extends previous estimates of this local survival probability to the entire MW. We find that towards the Galactic center, the survival probabilities drop drastically. Although we present results for a particular initial halo mass function, our simulations can be easily recast to different models using the provided data and code. Finally, we comment on the impact of our results on lensing, direct, and indirect detection.

    ↳ astro-ph.GAastro-ph.COhep-phPRD(2021)·72 citations
17. 17*

    Circular Polarization of Gravitational Waves from Early-Universe Helical Turbulence

    Tina Kahniashvili🇺🇸 · Axel Brandenburg🇸🇪 · Grigol Gogoberidze🇬🇪 · Sayan Mandal🇺🇸 · Alberto Roper Pol🇫🇷

    We perform direct numerical simulations to compute the net circular polarization of gravitational waves from helical (chiral) turbulent sources in the early Universe for a variety of initial conditions, including driven (stationary) and decaying turbulence. We investigate the resulting gravitational wave signal assuming different turbulent geneses such as magnetically or kinetically driven cases. Under realistic physical conditions in the early Universe we compute numerically the wave number-dependent polarization degree of the gravitational waves. We find that the spectral polarization degree strongly depends on the initial conditions. The peak of the spectral polarization degree occurs at twice the typical wavenumber of the source, as expected, and for fully helical decaying turbulence, it reaches its maximum of nearly 100\% {\it only} at the peak. We determine the temporal evolution of the turbulent sources as well as the resulting gravitational waves, showing that the dominant contribution to their spectral energy density happens shortly after the activation of the source. Only through an artificially prolonged decay of the turbulence can further increase of the gravitational wave amplitude be achieved. We estimate the detection prospects for the net polarization, arguing that its detection contains {\it clean} information (including the generation mechanisms, time, and strength) about the sources of possible parity violations in the early Universe.

    ↳ astro-ph.COgr-qchep-phphysics.flu-dynPRResearch(2021)·57 citations
18. 18*

    Diffusion of Cosmic Antiprotons Generated throughout the Dark Matter Halo -- A Semi-Analytical Solution for a Linear Galactic Wind Model

    Kwei-Chou Yang🇹🇼

    The public GALPROP code gives a fully numerical solution for the spectrum of cosmic rays propagating through a linear Galactic wind directed outwards from the Galactic plane in the framework of a cylindrical diffusion model. Alternatively, for the linear Galactic wind case, we present a semi-analytical solution of the two-zone cylindrical model which describes the spectrum of cosmic-ray antiprotons produced from the primary sources throughout the dark matter halo. While the secondary antiprotons can be generated by, e.g., the GALPROP WebRun, consistently using this semi-analytical solution for the primary ones would be helpful to build a suited dark matter (DM) model, which may be sophisticated, and then to perform a statistical analysis when confronting with data. As an example, using the obtained formula, we study the possible DM signal, through the channel $\text{DM DM}\to \bar{b}b$, and its constraint from the measurement of the AMS-02 antiproton-to-proton ratio. The indication of the DM signal is discussed. The advantage of the semi-analytical approach and its comparison with the GALPROP model are presented.

    ↳ astro-ph.HEastro-ph.COastro-ph.GAastro-ph.SR+1ApJ(2021)·0 citations
19. 19*

    Differential cohomology and topological actions in physics

    Joe Davighi🇬🇧 · Ben Gripaios🇬🇧 · Oscar Randal-Williams🇬🇧

    We use differential cohomology to systematically construct a large class of topological actions in physics, including Chern-Simons terms, Wess-Zumino-Novikov-Witten terms, and theta terms (continuous or discrete). We introduce a notion of invariant differential cohomology and use it to describe theories with global symmetries and we use equivariant differential cohomology to describe theories with gauge symmetries. There is a natural map from equivariant to invariant differential cohomology whose failure to surject detects 't Hooft anomalies, i.e. global symmetries which cannot be gauged. We describe a number of simple examples from quantum mechanics, such as a rigid body or an electric charge coupled to a magnetic monopole. We also describe examples of sigma models, such as those describing non-abelian bosonization in two dimensions, for which we offer an intrinsically bosonic description of the mod-2-valued 't Hooft anomaly that is traditionally seen by passing to the dual theory of Majorana fermions. Along the way, we describe a smooth structure on equivariant differential cohomology and prove various exactness and splitting properties that help with the characterization of both the equivariant and invariant theories.

    ↳ hep-thhep-phmath-phmath.AT+1Adv.Theor.Math.Phys.(2023)·25 citations
20. 20*

    Neural Empirical Bayes: Source Distribution Estimation and its Applications to Simulation-Based Inference

    Maxime Vandegar🇺🇸 · Michael Kagan🇺🇸 · Antoine Wehenkel🇧🇪 · Gilles Louppe🇧🇪

    We revisit empirical Bayes in the absence of a tractable likelihood function, as is typical in scientific domains relying on computer simulations. We investigate how the empirical Bayesian can make use of neural density estimators first to use all noise-corrupted observations to estimate a prior or source distribution over uncorrupted samples, and then to perform single-observation posterior inference using the fitted source distribution. We propose an approach based on the direct maximization of the log-marginal likelihood of the observations, examining both biased and de-biased estimators, and comparing to variational approaches. We find that, up to symmetries, a neural empirical Bayes approach recovers ground truth source distributions. With the learned source distribution in hand, we show the applicability to likelihood-free inference and examine the quality of the resulting posterior estimates. Finally, we demonstrate the applicability of Neural Empirical Bayes on an inverse problem from collider physics.

    ↳ stat.MLcs.LGhep-exhep-ph+134 citations
21. 21*

    About soft photon resummation

    Giulia Pancheri (INFN Frascati)🇮🇹 · Yogendra N. Srivastava (Perugia U.)🇮🇹

    The first time one of us (G.P.) encountered Earle was in Summer 1966, when she was directed to study Earle's papers on radiative corrections to quasi-elastic electron scattering. The suggestion had come from Bruno Touschek, at the time head of the theoretical physics group at the Frascati National Laboratories near Rome. About the same time, Earle came from MIT to visit University of Rome and Frascati. G.P. was a young post-graduate, who had studied Earle's papers and was awed by his already impressive scientific figure. After almost 40 years had passed, Earle visited Italy with his wife Ruth, making Frascati their base for an extended visit of almost a month. They were housed in what was then the laboratory hostel for foreign visitors, a small villa higher up above the hill, toward the town of Frascati. Since then, we became close friends, a friendship which included both his family and ours, and which has been very important for us. In memory of that first visit and in gratitude for the many years of friendship, we will tell here a story of infrared radiative corrections to charged particle scattering, to which Earle's papers gave an important contribution.

    ↳ physics.hist-phhep-ph2 citations
22. 22*

    Asymptotics of the banana Feynman amplitudes at the large complex structure limit

    Hiroshi Iritani🇯🇵

    Recently Bönisch-Fischbach-Klemm-Nega-Safari discovered, via numerical computation, that the leading asymptotics of the l-loop Banana Feynman amplitude at the large complex structure limit can be described by the Gamma class of a degree (1,...,1) Fano hypersurface F in (P^1)^{l+1}. We confirm this observation by using a Gamma-conjecture type result for F.

    ↳ math.AGhep-phhep-thAdv.Theor.Math.Phys.(2022)·7 citations
23. 23*

    The state is not abolished, it withers away: how quantum field theory became a theory of scattering

    Alexander S. Blum🇩🇪

    It is described how quantum field theory went from a theory for calculating the properties of stationary states, in the mold of quantum mechanics, to the scattering-focused theory we know today. This development is located as originating in the 1930s and 40s, primarily in the attempts by Werner Heisenberg and Richard Feynman to find a new theory of relativistic quantum mechanics that gets rid of the notion of state entirely. It is then shown how these attempts formed the conceptual inspiration and the provided the formal tools for the formulation of modern, scattering-based QFT in the late 1940s, in particular by Freeman Dyson (and, to some extent, by E.C.G. Stueckelberg). This transformation of quantum field theory is interpreted as a paradigm shift in a weak sense, where the foundations of the theory remain the same, while the paradigmatic problem to be calculated changes (in this case from energy levels to scattering amplitudes).

    ↳ physics.hist-phhep-phhep-thStud.Hist.Phil.Sci.B(2017)·26 citations
24. 24*

    Subleading BMS Charges and The Lorentz Group

    Uri Kol🇺🇸

    The extended BMS group includes supertranslation, dual supertranslation and Lorentz transformations. The generators of these symmetries can be classified according to their parity into "electric" and "magnetic" types. Using a multipole expansion of gravitational sources in the Newman-Penrose formalism, we associate each one of these charges with a particular moment. At leading order, the "electric" and "magnetic" monopole moments correspond respectively to supertranslations and dual supertranslations. At the first subleading order, the "electric" and "magnetic" dipole moments correspond respectively to boosts and rotations, therefore comprising the entire Lorentz group. Electric-magnetic type of duality then rotates the boost and rotation generators into each other.

    ↳ hep-thgr-qchep-phmath-ph+1JHEP(2022)·9 citations
25. 25*

    Constraints on ultralight scalar bosons within black hole spin measurements from LIGO-Virgo's GWTC-2

    Ken K. Y. Ng🇺🇸 · Salvatore Vitale🇺🇸 · Otto A. Hannuksela🇳🇱 · Tjonnie G. F. Li🇨🇳

    Clouds of ultralight bosons - such as axions - can form around a rapidly spinning black hole, if the black hole radius is comparable to the bosons' wavelength. The cloud rapidly extracts angular momentum from the black hole, and reduces it to a characteristic value that depends on the boson's mass as well as on the black hole mass and spin. Therefore, a measurement of a black hole mass and spin can be used to reveal or exclude the existence of such bosons. Using the black holes released by LIGO and Virgo in their GWTC-2, we perform a simultaneous measurement of the black hole spin distribution at formation and the mass of the scalar boson. We find that the data strongly disfavors the existence of scalar bosons in the mass range between $1.3\times 10^{-13}\mathrm{eV}$ and $2.7\times 10^{-13}\mathrm{eV}$ for a decay constant $f_a\gtrsim 10^{14}\mathrm{GeV}$. The statistical evidence is mostly driven by the two {binary black holes} systems GW190412 and GW190517, which host rapidly spinning black holes. The region where bosons are excluded narrows down if these two systems merged shortly ($\sim 10^5$ years) after the black holes formed.

    ↳ gr-qcastro-ph.HEhep-phPRL(2021)·137 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.