Mon·Jun 29, 2020Monday·June 29, 2020

1. 01*

   Improving the Understanding of Jet Grooming in Perturbation Theory

   Andrew J. Larkoski🇺🇸

   Jet grooming has emerged as a necessary and powerful tool in a precision jet physics program. In this paper, we present three results on jet grooming in perturbation theory, focusing on heavy jet mass in $e^{+}{e}^{-}\to$ hadrons collisions, groomed with the modified mass drop tagger. First, we calculate the analytic cross section at leading-order. Second, using the leading-order result and numerical results through next-to-next-to-leading order, we show that cusps in the distribution on the interior of phase space at leading-order are softened at higher orders. Finally, using analytic and numerical results, we show that terms that violate the assumptions of the factorization theorem for groomed jet mass are numerically much smaller than expected from power counting. These results provide important information regarding the convergence of perturbation theory for groomed jet observables and reliable estimates for residual uncertainties in a precision calculation.

   hep-phhep-exJHEP(2020)·18 citations
2. 02*

   The high energy window of probing dark matter with cosmic-ray antideuterium and antihelium

   Yu-Chen Ding🇨🇳 · Nan Li🇨🇳 · Chun-Cheng Wei🇨🇳 · Yu-Feng Zhou🇨🇳

   Cosmic-ray (CR) anti-nuclei are often considered as important observables for dark matter (DM) indirect detections at low kinetic energies below GeV per nucleon. Since the primary CR fluxes drop quickly towards high energies, the secondary anti-nuclei in CR are expected to be significantly suppressed in high energy regions ($\gtrsim 100$ GeV per nucleon). If DM particles are heavy, the annihilation productions of DM can be highly boosted, thus the fluxes of anti-nuclei produced by DM annihilations may exceed the secondary background at high energies, which opens a high energy window for DM indirect detections. We investigate the possibility of detecting heavy DM particles which annihilate into high energy anti-nuclei. We use Monte-Carlo generators $\text{PYTHIA}$, $\text{EPOS-LHC}$ and $\text{DPMJET}$ and the coalescence model to simulate the production of anti-nuclei, and constrain the DM annihilation cross sections by using the AMS-02 and HAWC antiproton data and the HESS galactic center gamma-ray data. We find that the conclusion depends on the choice of DM density profiles. For the "Cored" type profile with a DM particle mass $\gtrsim 10$ TeV, the contributions from DM annihilations can exceed the secondary background in high energy regions, which opens the high energy window. While for the "Cuspy" type profile, the excess disappears.

   hep-phCPC(2021)·1 citation
3. 03*

   Hadron production in elementary nucleon-nucleon reactions from low to ultra-relativistic energies

   V. Kireyeu🇷🇺 · I. Grishmanovskii🇩🇪 · V. Kolesnikov🇷🇺 · V. Voronyuk🇷🇺 · E. Bratkovskaya🇩🇪

   We study the hadron production in $p+p$, $p+n$ and $n+n$ reactions within the microscopic Parton-Hadron-Dynamics (PHSD) transport approach in comparison to PYTHIA 8.2. We discuss the details of the "PHSD tune" of the Lund string model (realized by event generators FRITIOF and PYTHIA) in the vacuum (as in $N+N$ collisions) as well as its in-medium modifications relevant for heavy-ion collisions where a hot and dense matter is produced. We compare the results of PHSD and PYTHIA 8.2 (default version) for the excitation function of hadron multiplicities as well as differential rapidity $y$, transverse momentum $p_T$ and $x_F$ distributions in $p+p$, $p+n$ and $n+n$ reactions with the existing experimental data in the energy range $\sqrt{s_{NN}}=2.7-7000$ GeV. We discuss the production mechanisms of hadrons and the role of final state interactions (FSI) due to the hadronic rescattering. We also show the influence of the possible quark-gluon plasma (QGP) formation on hadronic observables in $p+p$ collisions at LHC energies. We stress the importance of developing a reliable event generator for elementary reactions from low to ultra-relativistic energies in view of actual and upcoming heavy-ion experiments.

   hep-phhep-exnucl-thEPJA(2020)·28 citations
4. 04*

   Big-bang nucleosynthesis with sub-GeV massive decaying particles

   Masahiro Kawasaki🇯🇵 · Kazunori Kohri🇯🇵 · Takeo Moroi🇯🇵 · Kai Murai🇯🇵 · Hitoshi Murayama🇺🇸

   We consider the effects of the injections of energetic photon and electron (or positron) on the big-bang nucleosynthesis. We study the photodissociation of light elements in the early Universe paying particular attention to the case that the injection energy is sub-GeV and derive upper bounds on the primordial abundances of the massive decaying particle as a function of its lifetime. We also discuss a solution of the ${}^7$Li problem in this framework.

   hep-phastro-ph.COJCAP(2020)·61 citations
5. 05*

   Next-to-next-to-leading order corrections to quark Quasi parton distribution functions

   Long-Bin Chen🇨🇳 · Wei Wang🇨🇳 · Ruilin Zhu🇨🇳

   We present the next-to-next-to-leading order (NNLO) calculation of quark quasi parton distribution functions (PDFs) in the large momentum effective theory. The nontrivial factorization at this order is established explicitly and the full analytic matching coefficients between the quasi distribution and the lightcone distribution are derived. We demonstrate that the NNLO numerical contributions can improve the behavior of the extracted PDFs sizably. With the unprecedented precision study of nucleon tomography at the planned electron-ion collider, high precision Lattice QCD simulations with our NNLO results implemented will enable to test the QCD theory and more precise results on the PDFs of nucleons will be obtained.

   hep-phhep-latPRL(2021)·79 citations
6. 06*

   Polarized electroweak bosons in ${\text{W}}^{+}{\text{W}}^{-}$ production at the LHC including NLO QCD effects

   Ansgar Denner🇩🇪 · Giovanni Pelliccioli🇩🇪

   The measurement of polarization fractions of massive gauge bosons at the LHC provides an important check of the Standard Model and in particular of the Electroweak Symmetry Breaking mechanism. Owing to the unstable character of $\text{W}$ and $\text{Z}$ bosons, devising a theoretical definition for polarized signals is not straightforward and always subject to some ambiguity. Focusing on $\text{W}$-boson pair production at the LHC in the fully leptonic channel, we propose to compute polarized cross-sections and distributions based on the gauge-invariant doubly-resonant part of the amplitude. We include NLO QCD corrections to the leading quark-induced partonic process and also consider the loop-induced gluon-initiated process contributing to the same final state. We present results for both an inclusive setup and a realistic fiducial region, with special focus on variables that are suited for the discrimination of polarized cross-sections and on quantities that can be measured experimentally.

   hep-phJHEP(2020)·67 citations
7. 07*

   Flavour Symmetry Embedded -- GLoBES (FaSE-GLoBES)

   Jian Tang🇨🇳 · Tse-Chun Wang🇨🇳

   Neutrino models based on flavour symmetries provide the natural way to explain the origin of tiny neutrino masses. At the dawn of precision measurements of neutrino mixing parameters, neutrino mass models can be constrained and examined by on-going and up-coming neutrino experiments. We present a supplemental tool Flavour Symmetry Embedded (FaSE) for General Long Baseline Experiment Simulator (GLoBES), and it is available via the link https://github.com/tcwphy/FASE_GLoBES. It can translate the neutrino mass model parameters to standard neutrino oscillation parameters and offer prior functions in a user-friendly way. We demonstrate the robustness of FaSE-GLoBE with four examples on how the model parameters can be constrained and even whether the model is excluded by an experiment or not. We wish that this toolkit will facilitate the study of new neutrino mass models in an effecient and effective manner.

   hep-phComput.Phys.Commun.(2021)·2 citations
8. 08*

   The $Z_5$ model of two-component dark matter

   Geneviève Bélanger🇫🇷 · Alexander Pukhov🇷🇺 · Carlos Yaguna🇨🇴 · Oscar Zapata🇨🇴

   Scenarios for multi-component scalar dark matter based on a single $Z_N$ ($N\ge 4$) symmetry are simple and well-motivated. In this paper we investigate, for the first time, the phenomenology of the $Z_5$ model for two-component dark matter. This model, which can be seen as an extension of the well-known singlet scalar model, features two complex scalar fields--the dark matter particles--that are Standard Model singlets but have different charges under a $Z_5$ symmetry. The interactions allowed by the $Z_5$ give rise to novel processes between the dark matter particles that affect their relic densities and their detection prospects, which we study in detail. The key parameters of the model are identified and its viable regions are characterized by means of random scans. We show that, unlike the singlet scalar model, dark matter masses below the TeV are still compatible with present data. Even though the dark matter density turns out to be dominated by the lighter component, we find that current and future direct detection experiments may be sensitive to signals from both dark matter particles.

   hep-phJHEP(2020)·48 citations
9. 09*

   The nature of $X(3872)$ from high-multiplicity $pp$ collisions

   Angelo Esposito🇨🇭 · Elena G. Ferreiro🇪🇸 · Alessandro Pilloni🇮🇹 · Antonio D. Polosa🇮🇹 · Carlos A. Salgado🇪🇸

   The structure of exotic resonances that do not trivially fit the usual quark model expectations has been a matter of intense scientific debate during the last two decades. A possible way of estimating the size of these states is to study their behavior when immersed in QCD matter. Recently, LHCb has measured the relative abundance of the exotic $X(3872)$ over the ordinary $\psi (2S)$. We use the comover interaction model to study the yield of a compact $X(3872)$. To confirm the reliability of the model in high-multiplicity $pp$ collisions, we describe the suppression of excited over ground ${\rm Y}$ states. With this at hand, we show that the size of the compact $X(3872)$ would be slightly larger than that of the $\psi (2S)$. If the $X(3872)$ is instead assumed to be a meson molecule of large size, we argue that its evolution in QCD matter should be described via a coalescence model, as suggested by data on deuteron production. We show that the predictions of this model for the $X(3872)$ are in contrast with data.

   hep-phnucl-thEPJC(2021)·107 citations
10. 10*

    Exploring the robustness of stellar cooling constraints on light particles

    William DeRocco🇺🇸 · Peter W. Graham🇺🇸 · Surjeet Rajendran🇺🇸

    Stellar cooling arguments place strict restrictions on a wide variety of models of new physics. In this paper, we argue that mechanisms to evade these constraints are restricted by thermodynamic arguments, then present a minimal model extension that allows new particles to evade all stellar constraints. In doing this, we demonstrate that interesting parameter space can be reopened, using the EDGES signal and Xenon1T excess as examples. This mechanism highlights the importance of laboratory experiments in a well-controlled environment to search for new physics, complementary to astrophysical searches.

    hep-phPRD(2020)·105 citations
11. 11*

    Inverse Primakoff Scattering as a Probe of Solar Axions at Liquid Xenon Direct Detection Experiments

    James B. Dent🇺🇸 · Bhaskar Dutta🇺🇸 · Jayden L. Newstead🇦🇺 · Adrian Thompson🇺🇸

    We show that XENON1T and future liquid xenon (LXe) direct detection experiments are sensitive to axions through the standard $g_{a\gamma }aF\tilde{F}$ operators due to inverse-Primakoff scattering. This previously neglected channel significantly improves the sensitivity to the axion-photon coupling, with a reach extending to $g_{a\gamma }\sim 10^{-10}$ GeV${}^{-1}$ for axion masses up to a keV, thereby extending into the region of heavier QCD axion models. This result modifies the couplings required to explain the XENON1T excess in terms of solar axions, opening a large region of $g_{a\gamma }$ - $m_a$ parameter space which is not ruled out by the CAST helioscope experiment and reducing the tension with the astrophysical constraints. We explore the sensitivity to solar axions for future generations of LXe detectors which can exceed future helioscope experiments, such as IAXO, for a large region of parameter space.

    hep-phPRL(2020)·76 citations
12. 12*

    The JIMWLK evolution and the s-channel unitarity

    Alex Kovner🇺🇸 · Eugene Levin🇮🇱 · Ming Li🇺🇸 · Michael Lublinsky🇮🇱

    Further developing ideas set forth in \cite{KLL}, we discuss QCD Reggeon Field Theory (RFT) and formulate restrictions imposed on its Hamiltonian by the unitarity of underlying QCD. We identify explicitly the QCD RFT Hilbert space, provide algebra of the basic degrees of freedom (Wilson lines and their duals) and the algorithm for calculating the scattering amplitudes. We formulate conditions imposed on the "Fock states" of RFT by unitary nature of QCD, and explain how these constraints appear as unitarity constraints on possible RFT hamiltonians that generate energy evolution of scattering amplitudes. We study the realization of these constraints in the dense-dilute limit of RFT where the appropriate Hamiltonian is the JIMWLK Hamiltonian $H_{JIMWLK}$. We find that the action $H_{JIMWLK}$ on the dilute projectile states is unitary, but acting on dense "target" states it violates unitarity and generates states with negative probabilities through energy evolution.

    hep-phhep-thnucl-thJHEP(2020)·15 citations
13. 13*

    Hydrogen portal to exotic radioactivity

    David McKeen🇨🇦 · Maxim Pospelov🇺🇸 · Nirmal Raj🇨🇦

    We show that in a special class of dark sector models, the hydrogen atom can serve as a portal to new physics, through its decay occurring in abundant populations in the Sun and on Earth. The large fluxes of hydrogen decay daughter states can be detected via their decay or scattering. By constructing two models for either detection channel, we show that the recently reported excess in electron recoils at XENON1T could be explained by such signals in large regions of parameter space unconstrained by proton and hydrogen decay limits.

    hep-phastro-ph.HEhep-exPRL(2020)·53 citations
14. 14*

    Split SIMPs with Decays

    Andrey Katz🇨🇭 · Ennio Salvioni🇨🇭 · Bibhushan Shakya🇨🇭

    We discuss a minimal realization of the strongly interacting massive particle (SIMP) framework. The model includes a dark copy of QCD with three colors and three light flavors. A massive dark photon, kinetically mixed with the Standard Model hypercharge, maintains kinetic equilibrium between the dark and visible sectors. One of the dark mesons is necessarily unstable but long-lived, with potential impact on CMB observables. We show that an approximate "isospin" symmetry acting on the down-type quarks is an essential ingredient of the model. This symmetry stabilizes the dark matter and allows to split sufficiently the masses of the other states to suppress strongly their relic abundances. We discuss for the first time the SIMP cosmology with sizable mass splittings between all meson multiplets. We demonstrate that the SIMP mechanism remains efficient in setting the dark matter relic density, while CMB constraints on unstable relics can be robustly avoided. We also consider the phenomenological consequences of isospin breaking, including dark matter decay. Cosmological, astrophysical, and terrestrial probes are combined into a global picture of the parameter space. In addition, we outline an ultraviolet completion in the context of neutral naturalness, where confinement at the GeV scale is generic. We emphasize the general applicability of several novel features of the SIMP mechanism that we discuss here.

    hep-phastro-ph.COastro-ph.HEJHEP(2020)·35 citations
15. 15*

    Response-suggestion to The XENON1T excess: an overlooked dark matter signature?

    K. Zioutas🇬🇷 · G. Cantatore🇮🇹 · M. Karuza🇭🇷 · A. Kryemadhi🇺🇸 · M. Maroudas🇬🇷 · Y.K. Semertzidis🇰🇷

    The main alternatives of the recent XENON1T observation are solar axions, neutrino magnetic moment and tritium. In this short note we suggest to crosscheck whether the observation is related or not to dark matter (DM) streams, by searching for planetary dependence of the observed excess. If such a correlation is derived, this hint (<3.5sigma) can become the overlooked direct DM discovery. To do this it is necessary to analyze the time distribution of all the XENON1T data, and in particular the electronic events with their time stamp and energy. Notably, the velocities of the dark sector allow for planetary focusing effects towards the earth either by a single celestial body or combined by the whole solar system. Surprisingly, as yet this possibility has not been applied in the field of direct dark matter search, even though DM velocities fit-in well planetary gravitational lensing effects. The widely used signature of a direct dark matter search needs to be redefined, while, with luck, such an analysis might confirm or exclude the solar origin of the observed excess. Therefore, we suggest that XENON1T and DAMA release the data.

    hep-phastro-ph.EP15 citations
16. 16*

    Double parton distributions in the pion from lattice QCD

    Gunnar S. Bali🇩🇪 · Luca Castagnini🇩🇪 · Markus Diehl🇩🇪 · Jonathan R. Gaunt🇨🇭 · Benjamin Gläßle🇩🇪 · Andreas Schäfer🇩🇪 · Christian Zimmermann🇩🇪

    We perform a lattice study of double parton distributions in the pion, using the relationship between their Mellin moments and pion matrix elements of two local currents. A good statistical signal is obtained for almost all relevant Wick contractions. We investigate correlations in the spatial distribution of two partons in the pion, as well as correlations involving the parton polarisation. The patterns we observe depend significantly on the quark mass. We investigate the assumption that double parton distributions approximately factorise into a convolution of single parton distributions.

    ↳ hep-lathep-phJHEP(2021)·16 citations
17. 17*

    The art of simulating the early Universe -- Part I

    Daniel G. Figueroa🇪🇸 · Adrien Florio🇨🇭 · Francisco Torrenti🇨🇭 · Wessel Valkenburg🇨🇭

    We present a comprehensive discussion on lattice techniques for the simulation of scalar and gauge field dynamics in an expanding universe. After reviewing the continuum formulation of scalar and gauge field interactions in Minkowski and FLRW backgrounds, we introduce basic tools for the discretization of field theories, including lattice gauge invariant techniques. Following, we discuss and classify numerical algorithms, ranging from methods of $O(d{t}^2)$ accuracy like $staggeredleapfrog$ and $Verlet$ integration, to $Runge-Kutta$ methods up to $O(d{t}^4)$ accuracy, and the $Yoshida$ and $Gauss-Legendre$ higher-order integrators, accurate up to $O(d{t}^{10})$. We adapt these methods for their use in classical lattice simulations of the non-linear dynamics of scalar and gauge fields in an expanding grid in $3+1$ dimensions, including the case of `self-consistent' expansion sourced by the volume average of the fields' energy and pressure densities. We present lattice formulations of canonical cases of: $i)$ Interacting scalar fields, $ii)$ Abelian $U(1)$ gauge theories, and $iii)$ Non-Abelian $SU(2)$ gauge theories. In all three cases we provide symplectic integrators, with accuracy ranging from $O(d{t}^2)$ up to $O(d{t}^{10})$. For each algorithm we provide the form of relevant observables, such as energy density components, field spectra and the Hubble constraint. Remarkably, all our algorithms for gauge theories respect the Gauss constraint to machine precision, including when `self-consistent' expansion is considered. As a numerical example we analyze the post-inflationary dynamics of an oscillating inflaton charged under $SU(2)\times U(1)$. The present manuscript is meant as part of the theoretical basis for $CosmoLattice$, a modern C++ MPI-based package for simulating the non-linear dynamics of scalar-gauge field theories in an expanding universe, publicly available at www.cosmolattice.net

    ↳ astro-ph.COgr-qchep-lathep-ph+1JCAP(2021)·162 citations
18. 18*

    Long-baseline neutrino oscillation physics potential of the DUNE experiment

    DUNE Collaboration: B. Abi · R. Acciarri · M. A. Acero · G. Adamov · D. Adams · M. Adinolfi · Z. Ahmad · J. Ahmed · T. Alion · S. Alonso Monsalve · C. Alt · J. Anderson and 961 other authors

    The sensitivity of the Deep Underground Neutrino Experiment (DUNE) to neutrino oscillation is determined, based on a full simulation, reconstruction, and event selection of the far detector and a full simulation and parameterized analysis of the near detector. Detailed uncertainties due to the flux prediction, neutrino interaction model, and detector effects are included. DUNE will resolve the neutrino mass ordering to a precision of 5$\sigma$, for all ${\delta }_{\mathrm{CP}}$ values, after 2 years of running with the nominal detector design and beam configuration. It has the potential to observe charge-parity violation in the neutrino sector to a precision of 3$\sigma$ (5$\sigma$) after an exposure of 5 (10) years, for 50\% of all ${\delta }_{\mathrm{CP}}$ values. It will also make precise measurements of other parameters governing long-baseline neutrino oscillation, and after an exposure of 15 years will achieve a similar sensitivity to ${\sin }^{2}2{\theta }_{13}$ to current reactor experiments.

    ↳ hep-exhep-phEPJC(2020)·436 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.