PaperPanorama

HEP Phenomenology·hep-ph

Mon·Aug 31, 2020

23 papers15 primary·8 cross-listed·reconstructed*

  1. 01*

    Bounds on Lorentz-violating Yukawa couplings via lepton electromagnetic moments

    J. Alfonso Ahuatzi-Avendaño · Javier Montaño · Héctor Novales-Sánchez · Mónica Salinas · J. Jesús Toscano

    The effective-Lagrangian description of Lorentz-invariance violation provided by the so-called Standard-Model Extension covers all the sectors of the Standard Model, allowing for model-independent studies of high-energy phenomena that might leave traces at relatively-low energies. In this context, the quantification of the large set of parameters characterizing Lorentz-violating effects is well motivated. In the present work, effects from the Lorentz-nonconserving Yukawa sector on the electromagnetic moments of charged leptons are calculated, estimated, and discussed. Following a perturbative approach, explicit expressions of leading contributions are derived and upper bounds on Lorentz violation are estimated from current data on electromagnetic moments. Scenarios regarding the coefficients of Lorentz violation are considered. In a scenario of two-point insertions preserving lepton flavor, the bound on the electron electric dipole moment yields limits as stringent as , whereas muon and tau-lepton electromagnetic moments determine bounds as restrictive as and , respectively. Another scenario, defined by the assumption that Lorentz-violating Yukawa couplings are Hermitian, leads to less stringent bounds, provided by the muon anomalous magnetic moment, which turn out to be as restrictive as .

    hep-phPRD(2021)·8 citations
  2. 02*

    Single diffractive production of open heavy flavor mesons

    Marat Siddikov🇨🇱 · Ivan Schmidt🇨🇱

    In this paper we discuss the single diffractive production of open heavy flavor mesons and non-prompt charmonia in collisions. Using the color dipole approach, we found that the single diffractive production constitutes 0.5-2 per cent of the inclusive production of the same mesons. In Tevatron kinematics our theoretical results are in reasonable agreement with the available experimental data. In LHC kinematics we found that the cross-section is sufficiently large and could be accessed experimentally. We also analyzed the dependence on multiplicity of co-produced hadrons and found that it is significantly slower than that of inclusive production of the same heavy mesons.

    hep-phPRD(2020)·7 citations
  3. 03*

    Nucleon Tomography and Generalized Parton Distribution at Physical Pion Mass from Lattice QCD

    Huey-Wen Lin🇺🇸

    We present the first lattice calculation of the nucleon isovector unpolarized generalized parton distribution (GPD) at the physical pion mass using a lattice ensemble with 2+1+1 flavors of highly improved staggered quarks (HISQ) generated by MILC Collaboration, with lattice spacing ~fm and volume . We use momentum-smeared sources to improve the signal at nucleon boost momentum GeV, and report results at nonzero momentum transfers in . Nonperturbative renormalization in RI/MOM scheme is used to obtain the quasi-distribution before matching to the lightcone GPDs. The three-dimensional distributions and at are presented, along with the three-dimensional nucleon tomography and impact-parameter--dependent distribution for selected Bjorken at GeV in scheme.

    hep-phhep-latnucl-thPRL(2021)·113 citations
  4. 04*

    decay with an energetic photon

    Martin Beneke🇩🇪 · Christoph Bobeth🇩🇪 · Yu-Ming Wang🇨🇳

    We calculate the differential branching fraction, lepton forward-backward asymmetry and direct CP asymmetry for decays with an energetic photon. We employ factorization methods, which result in rigorous next-to-leading order predictions in the strong coupling at leading power in the large-energy/heavy-quark expansion, together with estimates of power corrections and a resonance parameterization of sub-leading power form factors in the region of small lepton invariant mass . The decay shares features of the charged-current decay , and the FCNC decays . As in the former, the leading-power decay rates can be expressed in terms of the -meson light-cone distribution amplitude and short-distance factors. However, similar to , four-quark and dipole operators contribute to the decay in an essential way, limiting the calculation to GeV below the charmonium resonances in the lepton invariant mass spectrum. A detailed analysis of the main observables and theoretical uncertainties is presented.

    hep-phJHEP(2020)·56 citations
  5. 05*

    More light on Higgs flavor at the LHC: Higgs couplings to light quarks through production

    J. A. Aguilar-Saavedra🇪🇸 · J. M. Cano🇪🇸 · J. M. No🇪🇸

    Higgs production in association with a photon at hadron colliders is a rare process, not yet observed at the LHC. We show that this process is sensitive to significant deviations of Higgs couplings to first and second generation SM quarks (particularly the up-type) from their SM values, and use a multivariate neural network analysis to derive the prospects of the High Luminosity LHC to probe deviations in the up and charm Higgs Yukawa couplings through production.

    hep-phhep-exPRD(2021)·33 citations
  6. 06*

    Models of decaying FIMP Dark Matter: potential links with the Neutrino Sector

    Laura Covi🇩🇪 · Avirup Ghosh🇮🇳 · Tanmoy Mondal🇰🇷 · Biswarup Mukhopadhyaya🇮🇳

    The absolute stability of a dark matter (DM) particle is not a binding requirement. Here we suggest a few scenarios where the DM particle is liable to decay via extremely feeble interactions. This can happen via inexplicably small Yukawa couplings in the simplest conjectures. After setting down such a model, we go beyond it, thus treading onto scenarios where the spontaneous breakdown of some gauged symmetry may lead to intermediate scales, and suitably suppressed effective operators which allow the DM particle to decay slowly. The constraints from particle physics as well as cosmology are taken into account in each case. The last and more involved scenario, studied in detail, suggest a link between the model parameters that govern neutrino physics on one side, and the dynamics of a quasi-stable DM particle on the other.

    hep-ph5 citations
  7. 07*

    An analysis of transverse momentum spectra of various jets produced in high energy collisions

    Yang-Ming Tai🇨🇳 · Pei-Pin Yang🇨🇳 · Fu-Hu Liu🇨🇳

    With the framework of the multi-source thermal model, we analyze the experimental transverse momentum spectra of various jets produced in different collisions at high energies. Two energy sources, a projectile participant quark and a target participant quark, are considered. Each energy source (each participant quark) is assumed to contribute to the transverse momentum distribution to be the TP-like function, i.e. a revised Tsallis--Pareto-type function. The contribution of the two participant quarks to the transverse momentum distribution is then the convolution of two TP-like functions. The model distribution can be used to fit the experimental spectra measured by different collaborations. The related parameters such as the entropy index-related, effective temperature, and revised index are then obtained. The trends of these parameters are useful to understand the characteristic of high energy collisions.

    hep-phhep-exnucl-exnucl-thAdv.High Energy Phys.(2021)·8 citations
  8. 08*

    Search for sterile neutrino with light gauge interactions: recasting collider, beam-dump, and neutrino telescope searches

    Yongsoo Jho🇰🇷 · Jongkuk Kim🇰🇷 · Pyungwon Ko🇰🇷 · Seong Chan Park🇰🇷

    We investigate features of the sterile neutrinos in the presence of a light gauge boson that couples to the neutrino sector. The novel bounds on the active-sterile neutrino mixings , especially for tau flavor (), from various collider and fixed target experiments are explored. Also, taking into account the additional decay channel of the sterile neutrino into a light gauge boson (), we explore and constrain a parameter space for low energy excess in neutrino oscillation experiments.

    hep-phhep-ex18 citations
  9. 09*

    Strong Coupling Constants of the Doubly Heavy Spin-1/2 Baryons with Light Pseudoscalar Mesons

    S. Rostami🇮🇷 · K. Azizi🇮🇷 · A. R. Olamaei🇮🇷

    The strong coupling constants of hadronic multiplets are fundamental parameters which carry information of the strong interactions among participating particles. These parameters can help us construct the hadron-hadron strong potential and gain information about the structure of the involved hadrons. Motivated by the recent observation of the doubly charmed state by LHCb, we determine the strong coupling constants among the doubly heavy spin-1/2 baryons, , and light pseudoscalar mesons, , , and within the framework of the light cone QCD sum rules. The obtained results may help experimental groups in analysis of the related data at hadron colliders.

    hep-phhep-exhep-latCPC(2021)·13 citations
  10. 10*

    Dark Photon from Light Scalar Boson Decays at FASER

    Takeshi Araki🇯🇵 · Kento Asai🇯🇵 · Hidetoshi Otono🇯🇵 · Takashi Shimomura🇯🇵 · Yosuke Takubo🇯🇵

    FASER is one of the promising experiments which search for long-lived particles beyond the Standard Model. In this paper, we focus on dark photon associating with an additional U(1) gauge symmetry, and also a scalar boson breaking this U(1) gauge symmetry. We study the sensitivity to the dark photon originated from U(1)-breaking scalar decays. We find that a sizable number of dark photon signatures can be expected in wider parameter space than previous studies.

    hep-phhep-exJHEP(2021)·31 citations
  11. 11*

    Collider searches of scalar singlets across lifetimes

    Elina Fuchs🇺🇸 · Oleksii Matsedonskyi🇮🇱 · Inbar Savoray🇮🇱 · Matthias Schlaffer🇺🇸

    Spin-0 singlets arise in well-motivated extensions of the Standard Model. Their lifetime determines the best search strategies at hadron and lepton colliders. To cover a large range of singlet decay lengths, we investigate bounds from Higgs decays into a pair of singlets, considering signatures of invisible decays, displaced and delayed jets, and coupling fits of untagged decays. We examine the generic scalar singlet and the relaxion, and derive a matching as well as qualitative differences between them. For each model, we discuss its natural parameter space and the searches probing it.

    hep-phhep-exJHEP(2021)·37 citations
  12. 12*

    PineAPPL: combining EW and QCD corrections for fast evaluation of LHC processes

    S. Carrazza🇮🇹 · E. R. Nocera🇳🇱 · C. Schwan🇮🇹 · M. Zaro🇮🇹

    We introduce PineAPPL, a library that produces fast-interpolation grids of physical cross sections, computed with a general-purpose Monte Carlo generator, accurate to fixed order in the strong, electroweak, and combined strong-electroweak couplings. We demonstrate this unique ability, that distinguishes PineAPPL from similar software available in the literature, by interfacing it to MadGraph5_aMC@NLO. We compute fast-interpolation grids, accurate to next-to-leading order in the strong and electroweak couplings, for a representative set of LHC processes for which EW corrections may have a sizeable effect on the accuracy of the corresponding theoretical predictions. We formulate a recommendation on the format of the experimental deliverables in order to consistently compare them with computations that incorporate EW corrections, and specifically to determine parton distribution functions to the same accuracy.

    hep-phhep-exJHEP(2020)·110 citations
  13. 13*

    Mass Unspecific Supervised Tagging (MUST) for boosted jets

    J. A. Aguilar-Saavedra🇪🇸 · F. R. Joaquim🇵🇹 · J. F. Seabra🇵🇹

    Jet identification tools are crucial for new physics searches at the LHC and at future colliders. We introduce the concept of Mass Unspecific Supervised Tagging (MUST) which relies on considering both jet mass and transverse momentum varying over wide ranges as input variables - together with jet substructure observables - of a multivariate tool. This approach not only provides a single efficient tagger for arbitrary ranges of jet mass and transverse momentum, but also an optimal solution for the mass correlation problem inherent to current taggers. By training neural networks, we build MUST-inspired generic and multi-pronged jet taggers which, when tested with various new physics signals, clearly outperform the variables commonly used by experiments to discriminate signal from background. These taggers are also efficient to spot signals for which they have not been trained. Taggers can also be built to determine, with a high degree of confidence, the prongness of a jet, which would be of utmost importance in case a new physics signal is discovered.

    hep-phhep-exJHEP(2021)·46 citations
  14. 14*

    Study of Transverse Spherocity and Azimuthal Anisotropy in Pb-Pb collisions at = 5.02 TeV using A Multi-Phase Transport Model

    Neelkamal Mallick🇮🇳 · Raghunath Sahoo🇮🇳 · Sushanta Tripathy🇲🇽 · Antonio Ortiz🇲🇽

    Transverse spherocity is an event shape observable having a very unique capability to separate the events based on their geometrical shapes. Recent results from experiments at the LHC suggest that transverse spherocity is an important event classifier in small collision systems. In this work, we use transverse spherocity for the first time in heavy-ion collisions and perform an extensive study on azimuthal anisotropy of charged particles produced in Pb-Pb collisions at TeV using A Multi-Phase Transport Model (AMPT). The azimuthal anisotropy is estimated using the 2-particle correlation method, which suppresses the non-flow effects significantly with an appropriate pseudorapidity gap of particle pairs. The results from AMPT are compared with estimations from PYTHIA8 (Angantyr) model and it is found that with the chosen pseudorapidity gap the residual non-flow effects become negligible. We found that the high spherocity events have nearly zero elliptic flow while low spherocity events contribute significantly to elliptic flow of spherocity-integrated events. Our studies indicate that using transverse spherocity in heavy-ion collisions, one can enhance and/or suppress the collective effects.

    hep-phhep-exnucl-exnucl-thJ.Phys.G(2021)·35 citations
  15. 15*

    Effective Field Theory approach to lepto-philic self conjugate dark matter

    Hrishabh Bharadwaj🇮🇳 · Ashok Goyal🇮🇳

    We study the self conjugate dark matter (DM) particles interacting primarily with the standard model leptons in an effective field theoretical frame work. We consider SM gauge invariant effective contact interactions between the Majorana fermion, real scalar and a real vector DM with leptons by evaluating the Wilson coefficients appropriate for interaction terms upto dimension-8 and obtain constraints on the parameters of the theory from the observed relic density, indirect detection observations and from the DM-electron scattering cross-sections in the direct detection experiments. Low energy LEP data has been used to study sensitivity in the pair production of such low mass 80 GeV DM particles. Pair production of DM particles of mass 50 GeV in association with mono-photons at the proposed ILC has rich potential to probe such effective operators.

    hep-phCPC(2021)·7 citations
  16. 16*

    PDFs and Neutrino-Nucleon Scattering from Hadronic Tensor

    Jian Liang🇺🇸 · Keh-Fei Liu🇺🇸

    We review the Euclidean path-integral formulation of the nucleon hadronic tensor and classify the gauge invariant and topologically distinct insertions in terms of connected and disconnected insertions and also in terms of leading and higher-twist contributions in the DIS region. Converting the Euclidean hadronic tensor back to the Minkowski space requires solving an inverse problem of the Laplace transform. We have investigated several inverse algorithms and studied the pros and cons of each. We show a result with a relatively large momentum transfer () to suppress the elastic scattering and reveal the contributions from the resonance and inelastic region of the neutrino-nucleon scattering. For elastic scattering, the hadronic tensor is the the product of the elastic form factors for the two corresponding currents. We checked numerically for the case of two charge vector currents () with the electric form factor calculated from the three-point function and found they agree within errors.

    hep-lathep-phPoS(2020)·15 citations
  17. 17*

    Obstacles to Constructing de Sitter Space in String Theory

    Michael Dine🇺🇸 · Jamie A.P. Law-Smith🇺🇸 · Shijun Sun🇺🇸 · Duncan Wood🇺🇸 · Yan Yu🇺🇸

    There have been many attempts to construct de Sitter space-times in string theory. While arguably there have been some successes, this has proven challenging, leading to the de Sitter swampland conjecture: quantum theories of gravity do not admit stable or metastable de Sitter space. Here we explain that, within controlled approximations, one lacks the tools to construct de Sitter space in string theory. Such approximations would require the existence of a set of (arbitrarily) small parameters, subject to severe constraints. But beyond this one also needs an understanding of big-bang and big-crunch singularities that is not currently accessible to standard approximations in string theory. The existence or non-existence of metastable de Sitter space in string theory remains a matter of conjecture.

    hep-thhep-phJHEP(2021)·33 citations
  18. 18*

    Spin Order and Entropy in Antiferromagnetic Films Subjected to Magnetic Fields

    Christoph P. Hofmann🇲🇽

    Using systematic effective field theory, we explore the properties of antiferromagnetic films subjected to magnetic and staggered fields that are either mutually aligned or mutually orthogonal. We provide low-temperature series for the entropy density in either case up to two-loop order. Invoking staggered, uniform and sublattice magnetizations of the bipartite antiferromagnet, we investigate the subtle order-disorder phenomena in the spin arrangement, induced by temperature, magnetic and staggered fields -- some of which are quite counterintuitive. In the figures we focus on the spin- square-lattice antiferromagnet, but our results are valid for any other bipartite two-dimensional lattice.

    cond-mat.str-elhep-lathep-phJ.Stat.Mech.(2021)·0 citations
  19. 19*

    Primordial black holes from long-range scalar forces and scalar radiative cooling

    Marcos M. Flores🇺🇸 · Alexander Kusenko🇺🇸

    We describe a new scenario for the formation of primordial black holes (PBHs). In the early Universe, the long-range forces mediated by the scalar fields can lead to formation of halos of heavy particles even during the radiation-dominated era. The same interactions result in the emission of scalar radiation from the motion and close encounters of particles in such halos. Radiative cooling due the scalar radiation allows the halos to collapse to black holes. We illustrate this scenario on a simple model with fermions interacting via the Yukawa forces. The abundance and the mass function of PBHs are suitable to account for all dark matter, or for some gravitational wave events detected by LIGO. The model relates the mass of the dark-sector particles to the masses and abundance of dark matter PBHs in a way that can explain why the dark matter and the ordinary matter have similar mass densities. The model also predicts a small contribution to the number of effective light degrees of freedom, which can help reconcile different measurements of the Hubble constant.

    astro-ph.COhep-phPRL(2021)·98 citations
  20. 20*

    A multi-wavelength study of PSR J11196127 after 2016 outburst

    H.-H. Wang🇺🇸 · L.C.-C. Lin🇰🇷 · S. Dai🇦🇺 · J. Takata🇨🇳 · K.L. Li.🇰🇷 · C.-P. Hu🇯🇵 · X. Hou🇨🇳

    PSR~J11196127, a high-magnetic field pulsar detected from radio to high-energy wavelengths, underwent a magnetar-like outburst beginning on July 27, 2016. In this paper, we study the post-outburst multi-wavelength properties of this pulsar from the radio to GeV bands and discuss its similarity with the outburst of the magnetar XTE~J1810197. In phase-resolved spectral analysis of 0.5--10\,keV X-ray data collected in August 2016, the on-pulse and off-pulse spectra are both characterized by two blackbody components and also require a power-law component similar to the hard X-ray spectra of magnetars. This power-law component is no longer distinguishable in data from December, 2016. We likewise find that there was no substantial shift between the radio and X-ray pulse peaks after the 2016 X-ray outburst. The gamma-ray pulsation after the X-ray outburst is confirmed with data taken after 2016 December and the pulse structure and phase difference between the gamma-ray and radio peaks (0.4 cycle) are also consistent with those before the X-ray outburst. These multi-wavelength observations suggest that the re-configuration of the global magnetosphere after 2016 magnetar-like outburst at most continued for about six months. We discuss the evolution of the X-ray emission after the 2016 outburst with the untwisting magnetosphere model.

    astro-ph.HEhep-phApJ(2020)·8 citations
  21. 21*

    CYGNUS: Feasibility of a nuclear recoil observatory with directional sensitivity to dark matter and neutrinos

    S. E. Vahsen🇺🇸 · C. A. J. O'Hare🇦🇺 · W. A. Lynch🇬🇧 · N. J. C. Spooner🇬🇧 · E. Baracchini🇮🇹 · P. Barbeau🇺🇸 · J. B. R. Battat🇺🇸 · B. Crow🇺🇸 · C. Deaconu🇺🇸 · C. Eldridge🇬🇧 · A. C. Ezeribe🇬🇧 · M. Ghrear🇺🇸 and 7 other authors

    Now that conventional weakly interacting massive particle (WIMP) dark matter searches are approaching the neutrino floor, there has been a resurgence of interest in detectors with sensitivity to nuclear recoil directions. A large-scale directional detector is attractive in that it would have sensitivity below the neutrino floor, be capable of unambiguously establishing the galactic origin of a purported dark matter signal, and could serve a dual purpose as a neutrino observatory. We present the first detailed analysis of a 1000 m-scale detector capable of measuring a directional nuclear recoil signal at low energies. We propose a modular and multi-site observatory consisting of time projection chambers (TPCs) filled with helium and SF at atmospheric pressure. Depending on the TPC readout technology, 10-20 helium recoils above 6 keVr or only 3-4 recoils above 20 keVr would suffice to distinguish a 10 GeV WIMP signal from the solar neutrino background. High-resolution charge readout also enables powerful electron background rejection capabilities well below 10 keV. We detail background and site requirements at the 1000 m-scale, and identify materials that require improved radiopurity. The final experiment, which we name CYGNUS-1000, will be able to observe 10-40 neutrinos from the Sun, depending on the final energy threshold. With the same exposure, the sensitivity to spin independent cross sections will extend into presently unexplored sub-10 GeV parameter space. For spin dependent interactions, already a 10 m-scale experiment could compete with upcoming generation-two detectors, but CYGNUS-1000 would improve upon this considerably. Larger volumes would bring sensitivity to neutrinos from an even wider range of sources, including galactic supernovae, nuclear reactors, and geological processes.

    physics.ins-detastro-ph.COhep-exhep-ph140 citations
  22. 22*

    Decoding Dark Matter Substructure without Supervision

    Stephon Alexander🇺🇸 · Sergei Gleyzer🇺🇸 · Hanna Parul🇺🇸 · Pranath Reddy🇮🇳 · Michael W. Toomey🇺🇸 · Emanuele Usai🇺🇸 · Ryker Von Klar🇺🇸

    The identity of dark matter remains one of the most pressing questions in physics today. While many promising dark matter candidates have been put forth over the last half-century, to date the true identity of dark matter remains elusive. While it is possible that one of the many proposed candidates may turn out to be dark matter, it is at least equally likely that the correct physical description has yet to be proposed. To address this challenge, novel applications of machine learning can help physicists gain insight into the dark sector from a theory agnostic perspective. In this work we demonstrate the use of unsupervised machine learning techniques to infer the presence of substructure in dark matter halos using galaxy-galaxy strong lensing simulations.

    astro-ph.COhep-ph29 citations
  23. 23*

    Prospects for Beyond the Standard Model Physics Searches at the Deep Underground Neutrino 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 965 other authors

    The Deep Underground Neutrino Experiment (DUNE) will be a powerful tool for a variety of physics topics. The high-intensity proton beams provide a large neutrino flux, sampled by a near detector system consisting of a combination of capable precision detectors, and by the massive far detector system located deep underground. This configuration sets up DUNE as a machine for discovery, as it enables opportunities not only to perform precision neutrino measurements that may uncover deviations from the present three-flavor mixing paradigm, but also to discover new particles and unveil new interactions and symmetries beyond those predicted in the Standard Model (SM). Of the many potential beyond the Standard Model (BSM) topics DUNE will probe, this paper presents a selection of studies quantifying DUNE's sensitivities to sterile neutrino mixing, heavy neutral leptons, non-standard interactions, CPT symmetry violation, Lorentz invariance violation, neutrino trident production, dark matter from both beam induced and cosmogenic sources, baryon number violation, and other new physics topics that complement those at high-energy colliders and significantly extend the present reach.

    hep-exhep-phEPJC(2021)·253 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.