Thu·Aug 20, 2020Thursday·August 20, 2020

1. 01*

   The role of the chiral anomaly in polarized deeply inelastic scattering I: Finding the triangle graph inside the box diagram in Bjorken and Regge asymptotics

   Andrey Tarasov🇺🇸 · Raju Venugopalan🇺🇸

   We revisit the role of the chiral "triangle" anomaly in deeply inelastic scattering (DIS) of electrons off polarized protons employing a powerful worldline formalism. We demonstrate how the triangle anomaly appears at high energies in the DIS box diagram for the polarized proton structure function $g_1(x_B,Q^2)$ in both the Bjorken limit of large $Q^2$ and in the Regge limit of small $x_B$. We show that the operator product expansion is not required to extract the anomaly in either asymptotics though it is sufficient in the Bjorken limit. Likewise, the infrared pole in the anomaly arises in both limits. The leading contribution to $g_1$, in both Bjorken and Regge asymptotics, is therefore given by the expectation value of the topological charge density, generalizing a result previously argued by Jaffe and Manohar to hold for the first moment of $g_1$. In follow-up work, we will show how our results motivate the derivation of a helicity-dependent effective action incorporating the physics of the anomaly at small $x_B$ and shall discuss the QCD evolution of $g_1(x_B,Q^2)$ in this framework.

   hep-phhep-thnucl-thPRD(2020)·51 citations
2. 02*

   Impact of correlations between $a_{\mu }$ and ${\alpha }_{QED}$ on the EW fit

   Bogdan Malaescu🇫🇷 · Matthias Schott🇩🇪

   We study the potential impact on the electroweak (EW) fits due to the tensions between the current determinations of the hadronic vacuum polarisation (HVP) contributions to the anomalous magnetic moment of the muon ($a_{\mu }$), based on either phenomenological dispersion integrals using measured hadronic spectra or on Lattice QCD calculations. The impact of the current tension between the experimental measurement of $a_{\mu }$ and the total theoretical prediction based on the phenomenological calculations of the HVP are also studied. The correlations between the uncertainties of the theoretical predictions of $a_{\mu }$ and of the running of ${\alpha }_{QED}$ are taken into account in the studies. We conclude that the impact on the EW fit can be large in improbable scenarios involving global shifts of the full HVP contribution, while it is much smaller if the shift is restricted to a lower mass range and/or if the shift in ${\alpha }_{QED}$ is obtained from that in $a_{\mu }$ through appropriate use of the correlations. Indeed, the latter scenarios only imply at most a 2.6/16 increase in the ${\chi }^2/n.d.f.$ of the EW fits and relatively small changes for the resulting fit parameter values.

   hep-phhep-exEPJC(2021)·108 citations
3. 03*

   Dark Scalars and Heavy Neutral Leptons at DarkQuest

   Brian Batell🇺🇸 · Jared A. Evans🇺🇸 · Stefania Gori🇺🇸 · Mudit Rai🇺🇸

   The proposed DarkQuest beam dump experiment, a modest upgrade to the existing SeaQuest/SpinQuest experiment, has great potential for uncovering new physics within a dark sector. We explore both the near-term and long-term prospects for observing two distinct, highly-motivated hidden sector benchmark models: heavy neutral leptons and Higgs-mixed scalars. We comprehensively examine the particle production and detector acceptance at DarkQuest, including an updated treatment of meson production, and light scalar production through both bremsstrahlung and gluon-gluon fusion. In both benchmark models, DarkQuest will provide an opportunity to probe previously inaccessible interesting regions of parameter space on a fairly short timescale when compared to other proposed experiments.

   hep-phJHEP(2021)·73 citations
4. 04*

   Beyond the MSW effect: Neutrinos in a dense medium

   Antonio Capolupo🇮🇹 · Salvatore Marco Giampaolo🇭🇷 · Aniello Quaranta🇮🇹

   We present a theory of neutrino oscillations in a dense medium which goes beyond the effective matter potential used in the description of the MSW effect. We show how the purity of the neutrino state is degraded by neutrino interactions with the environment and how neutrino--matter interactions can be a source of decoherence. We present new oscillation formulae for neutrinos interacting with leptons and carry out a numerical analysis which exhibits deviations from the MSW formulae for propagation through the Earth of ultra-high energy neutrinos. In particular, we show that at high density and/or high neutrino energy, the vanishing transition probabilities derived for MSW effect, are non zero when the scattering is taken into account.

   hep-phnucl-thPLB(2021)·26 citations
5. 05*

   Electric quadrupole form factors of singly heavy baryons with spin 3/2

   June-Young Kim🇩🇪 · Hyun-Chul Kim🇰🇷

   We study the electromagnetic form factors of the lowest-lying singly heavy baryons in a pion mean-field approach, which is also known as the SU(3) chiral quark-soliton model. In the limit of the heavy-quark mass, the dynamics inside a singly heavy baryon is governed by the $N_c-1$ valence quarks, while the heavy quark remains as a mere static color source. In this framework, a singly heavy baryon is described by combining the colored soliton with the singly heavy quark. In the infinitely heavy-quark mass limit, we can compute the electric quadrupole form factors of the baryon sextet with spin 3/2 with the rotational $1/N_c$ and linear corrections of the explicit flavor SU(3) symmetry breaking taken into account. We find that the sea-quark contributions or the Dirac-sea level contributions dominate over the valence-quark contributions in lower $Q^2$ region. We examined the effects of explicit flavor SU(3) symmetry breaking in detail. The numerical results are also compared with the recent data from the lattice calculation with the unphysical value of the pion mass considered, which was used in the lattice calculation.

   hep-phhep-exhep-latPTEP(2021)·9 citations
6. 06*

   Double parton scattering in four-jet production in proton-proton collisions at the LHC

   Oleh Fedkevych🇮🇹 · Anna Kulesza🇩🇪

   We study the contribution from double parton scattering (DPS) to four-jet production at the LHC, both at the leading order accuracy and after incorporating the effects of QCD radiation. Apart from DPS, we also include and discuss the contribution from single parton scattering (SPS). We find that the QCD radiation impacts theoretical predictions significantly, with DPS contributions more affected than the SPS. We also examine a number of observables in regard to their effectiveness for discrimination between DPS and SPS events and propose sets of kinematical cuts to improve the prospects of measuring DPS in four-jet production.

   hep-phPRD(2021)·15 citations
7. 07*

   Two relativistic Kondo effects: Classification with particle and antiparticle impurities

   Yasufumi Araki🇯🇵 · Daiki Suenaga🇯🇵 · Kei Suzuki🇯🇵 · Shigehiro Yasui🇯🇵

   We investigate two different types of relativistic Kondo effects, distinguished by heavy-impurity degrees of freedom, by focusing on the energy-momentum dispersion relations of the ground state with condensates composed of a light Dirac fermion and a nonrelativistic impurity fermion. Heavy fermion degrees of freedom are introduced in terms of two types of heavy-fermion effective theories, in other words, two heavy-fermion limits for the heavy Dirac fermion, which are known as the heavy-quark effective theories (HQETs) in high-energy physics. While the first one includes only the heavy-particle component, the second one contains both the heavy-particle and heavy-antiparticle components, which are opposite in their parity. From these theories, we obtain two types of Kondo effects, in which the dispersions near the Fermi surface are very similar, but they differ in the structure at low momentum. We also classify the possible forms of condensates in the two limits. The two Kondo effects will be examined by experiments with Dirac/Weyl semimetals or quark matter, lattice simulations, and cold-atom simulations.

   hep-phcond-mat.mes-hallcond-mat.str-elPRResearch(2021)·9 citations
8. 08*

   Hard-core deconfinement and soft-surface delocalization from nuclear to quark matter

   Kenji Fukushima🇯🇵 · Toru Kojo🇨🇳 · Wolfram Weise🇩🇪

   We propose a conceptual distinction between hard and soft realizations of deconfinement from nuclear to quark matter. In the high density region of Hard Deconfinement the repulsive hard cores of baryons overlap each other and bulk thermodynamics is dominated by the core properties that can be experimentally accessed in high-energy scattering experiments. We find that the equation of state estimated from a single baryon core is fairly consistent with those empirically known from neutron star phenomenology. We next discuss a novel concept of Soft Deconfinement, characterized by quantum percolation of quark wave-functions, at densities lower than the threshold for Hard Deconfinement. We make a brief review of quantum percolation in the context of nuclear and quark matter and illustrate a possible scenario of quark deconfinement at high baryon densities.

   hep-phnucl-thPRD(2020)·90 citations
9. 09*

   Exploring New Physics in $B\to \pi K$ Decays

   Eleftheria Malami🇳🇱

   B-meson decays play an important role in flavour physics. The $B\to \pi K$ decays are dominated by QCD loop diagrams (penguins) but also electroweak penguins, where New Physics may enter, have a significant impact on the decay amplitude. Since measurements from B-factories indicate deviations from the Standard Model picture, we perform a state-of-the-art analysis to explore the correlation of the CP asymmetries and to get an updated picture. We propose a strategy for the optimal determination of the parameters which describe electroweak penguin effects and apply it to current data, utilising both neutral and charged $B\to \pi K$ decays. This new method can be fully exploited at the future Belle-II experiment, which will hopefully answer the question: Do these decays imply New Physics?

   hep-phPoS(2020)·2 citations
10. 10*

    Muon Flavor Violation in Two Higgs Doublet Model with Extra Yukawa Couplings

    Wei-Shu Hou🇹🇼 · Girish Kumar🇹🇼

    The new round of experiments, MEG II, COMET/Mu2e, and Mu3e, would soon start to push the $\mu \to e\gamma$, $\mu N\to eN$ conversion, and $\mu \to 3e$ frontier, while Belle II would probe $\tau \to \mu \gamma$ and $\tau \to 3\mu$. In the general two Higgs doublet model with extra Yukawa couplings, we show that all these processes probe the lepton flavor violating (LFV) dipole transition that arises from the two loop mechanism, with scalar-induced contact terms subdominant. This is because existing data suggest the extra Yukawa couplings ${\rho }_{\mu e},{\rho }_{ee}\lesssim {\lambda }_e$, while ${\rho }_{\tau \mu },{\rho }_{\tau \tau }\lesssim {\lambda }_{\tau }$ and ${\rho }_{tt}\lesssim {\lambda }_t$, with ${\lambda }_i$ the usual Yukawa coupling of the Standard Model (SM), where ${\rho }_{\mu e}{\rho }_{tt}$ and ${\rho }_{\tau \mu }{\rho }_{tt}$ enter the $\mu e\gamma$ and $\tau \mu \gamma$ two loop amplitudes, respectively. With the $B_s\to \mu \mu$ decay rate basically consistent with SM expectation, together with the $B_s$ mixing constraint, we show that $B_s\to \tau \tau$ would also be consistent with SM, while $B_s\to \tau \mu$ and $B\to K\tau \mu$ decays would be out of reach of projected sensitivities, in strong contrast with some models motivated by the B anomalies.

    hep-phPRD(2020)·20 citations
11. 11*

    Lorentz and CPT tests with charge-to-mass ratio comparisons in Penning traps

    Yunhua Ding🇺🇸 · Mohammad Farhan Rawnak🇺🇸

    Applications of the general theory of quantum electrodynamics with Lorentz- and CPT-violating operators of mass dimensions up to six are presented to Penning-trap experiments comparing charge-to-mass ratios between particles and antiparticles. Perturbation theory is used to derive Lorentz- and CPT-violating contributions to the energy levels and cyclotron frequencies of confined particles and antiparticles. We show that whether the experimental {\it interpreted} quantity $(|q|/m{)}_{\overline{w}}/(|q|/m{)}_w-1$ is a clean measure of a CPT test depends on the context of the relevant theory. Existing experimental results of charge-to-mass ratio comparisons are used to obtain first-time constraints on 69 coefficients for Lorentz and CPT violation.

    hep-phPRD(2020)·33 citations
12. 12*

    Scaling properties of jet-momentum profiles with multiplicity

    Antal Gemes (1,2)🇭🇺 · Robert Vertesi (1)🇭🇺 · Gabor Papp (3)🇭🇺 · Gergely Gabor Barnafoldi (1) ((1) Wigner Research Centre for Physics, (2) Trinity College, University of Cambridge, (3) Institute of Physics, Eotvos Lorand University)🇭🇺

    We study the structure of jets in proton-proton collisions at LHC energies using \textsc{Pythia} 8 Monte Carlo simulations. We demonstrate that the radial jet profiles exhibit scaling properties with charged-hadron event multiplicity over a broad transverse-momentum range. We also provide parametrizations of the jet profiles based on different statistically-motivated analytical distributions. Based on this we propose that the scaling behavior stems from fundamental statistical properties of jet fragmentation.

    hep-phGribov-90 Memorial Volume, pp. 81-89 (202…·3 citations
13. 13*

    Stochastic Baryogenesis

    Yi-Peng Wu🇫🇷 · Kalliopi Petraki🇫🇷

    Using a multi-field stochastic approach, we investigate the vacuum expectation value (VEV) during inflation of a scalar field charged under a mildly broken global $U(1)$ symmetry that can play the role of baryon or lepton number, or possibly a dark baryon number or a combination of the three. Even for a CP invariant Lagrangian, the stochastic distribution of inflationary VEVs in general breaks CP spontaneously, allowing for successful baryogenesis via the Affleck-Dine mechanism. For the Hubble scale during inflation $H_{\ast }$ as high as $10^{13}$ GeV, we show that the post-inflationary relaxation of the charged scalar with stochastic initial conditions can explain the observed baryon asymmetry, and that a charged scalar mass at the order of $H_{\ast }$ is favored by the isocurvature constraints.

    hep-phastro-ph.COJCAP(2021)·9 citations
14. 14*

    Generative Networks for LHC events

    Anja Butter🇩🇪 · Tilman Plehn🇩🇪

    LHC physics crucially relies on our ability to simulate events efficiently from first principles. Modern machine learning, specifically generative networks, will help us tackle simulation challenges for the coming LHC runs. Such networks can be employed within established simulation tools or as part of a new framework. Since neural networks can be inverted, they also open new avenues in LHC analyses.

    hep-ph47 citations
15. 15*

    SiC Detectors for Sub-GeV Dark Matter

    Sinéad M. Griffin🇺🇸 · Yonit Hochberg🇮🇱 · Katherine Inzani🇺🇸 · Noah Kurinsky🇺🇸 · Tongyan Lin🇺🇸 · To Chin Yu🇺🇸

    We propose the use of silicon carbide (SiC) for direct detection of sub-GeV dark matter. SiC has properties similar to both silicon and diamond, but has two key advantages: (i) it is a polar semiconductor which allows sensitivity to a broader range of dark matter candidates; and (ii) it exists in many stable polymorphs with varying physical properties, and hence has tunable sensitivity to various dark matter models. We show that SiC is an excellent target to search for electron, nuclear and phonon excitations from scattering of dark matter down to 10 keV in mass, as well as for absorption processes of dark matter down to 10 meV in mass. Combined with its widespread use as an alternative to silicon in other detector technologies and its availability compared to diamond, our results demonstrate that SiC holds much promise as a novel dark matter detector.

    hep-phastro-ph.COcond-mat.mtrl-scihep-ex+1PRD(2021)·128 citations
16. 16*

    Anomaly-free chiral $U(1{)}_D$ and its scotogenic implication

    Chi-Fong Wong🇨🇳

    We assume a dark $U_D$ symmetric hidden sector and explore its possible content such that neutrino mass and Dark Matter are generated through the scotogenic mechanism. The hidden sector is considered analogue to the Standard Model, namely the charge assignment of hidden fermions is chiral and anomaly-free. Moreover, $U_D$ is assumed broken by an only Higgs singlet that also generates masses to all hidden fermions, therefore the charge assignment is subjected to additional restriction. We search by computer program for charge assignments satisfying all these conditions, and identify the resulting minimal scotogenic models for Majorana neutrinos and Dirac neutrinos respectively in the sense of minimal number of messenger scalar involved. Particle spectrum, couplings, and phenomenologies of these minimal models are briefly discussed. DM is found multicomponent and always contains Dirac fermionic species.

    hep-phPhys.Dark Univ.(2021)·14 citations
17. 17*

    Loop spin effects in intense background fields

    Anton Ilderton🇬🇧 · Ben King🇬🇧 · Suo Tang🇬🇧

    Radiative and non-radiative electron spin flip probabilities are analysed in both plane wave and focussed laser backgrounds. We provide a simple and physically transparent description of spin dynamics in plane waves, and demonstrate that there exists a kinematic regime in which the usual leading order perturbative hierarchy of QED is reversed, and non-radiative loop effects dominate over radiative tree-level spin-flips. We show that while this loop-dominance becomes suppressed in focussed laser pulses due to a high sensitivity to field geometry, there is nevertheless a regime in which, in principle, loop effects on spin transitions can be discerned.

    hep-phPRD(2020)·32 citations
18. 18*

    Probing Dark Matter with Disappearing Tracks at the LHC

    Alexander Belyaev🇬🇧 · Stefan Prestel🇸🇪 · Felipe Rojas-Abbate🇬🇧 · Jose Zurita🇩🇪

    Models where dark matter is a part of an electroweak multiplet feature charged particles with macroscopic lifetimes due to the charged-neutral mass split of the order of pion mass. At the Large Hadron Collider, the ATLAS and CMS experiments will identify these charged particles as disappearing tracks, since they decay into a massive invisible dark matter candidate and a very soft charged Standard-Model particle which fails to pass the reconstruction requirements. While ATLAS and CMS have focused on the supersymmetric versions of these scenarios, we have performed here the reinterpretation of the latest ATLAS disappearing track search for a suite of dark matter multiplets with different spins and electroweak quantum numbers. More concretely, we consider the cases of the inert Two Higgs Doublet model (i2HDM), of Minimal Fermion Dark Matter (MFDM) and of Vector Triplet Dark Matter (VTDM). Our procedure is validated by using the same wino and higgsino benchmark models employed by the ATLAS collaboration. We have found that with the disappearing track signature one can probe a vast portion of the parameter space, well beyond the reach of prompt missing energy searches (notably mono-jets). We provide tables with the upper-limits on the cross-section upper limits, and efficiencies in the lifetime - dark matter mass plane for all the models under consideration. Moreover we make the recasting code employed here publicly available, as part of the LLP Recasting Repository.

    hep-phPRD(2021)·34 citations
19. 19*

    Dark Photons in the Solar Basin

    Robert Lasenby🇺🇸 · Ken Van Tilburg🇺🇸

    Production of dark photons inside the Sun forms the basis for the most sensitive probes of such particles over a wide mass range. A small fraction of dark photons is emitted into gravitationally bound orbits, building up a "Solar basin" population that survives for astrophysically long times. We show that this population could lead to signals in existing and proposed dark matter detection experiments, opening up significant new parameter space independent of whether dark photons make up the dark matter. Even with conservative assumptions, results from current dark matter experiments already constrain new parameter space; with fiducial assumptions, a Solar basin population of dark photons could be responsible for excess events seen in XENON1T. Future low-threshold experiments could be sensitive to these Solar-System-bound dark photons down to sub-eV masses, at couplings orders of magnitude below current constraints.

    hep-phastro-ph.HEastro-ph.SRhep-exPRD(2021)·33 citations
20. 20*

    Data-driven quark and gluon jet modification in heavy-ion collisions

    Jasmine Brewer🇺🇸 · Jesse Thaler🇺🇸 · Andrew P. Turner🇺🇸

    Whether quark- and gluon-initiated jets are modified differently by the quark-gluon plasma produced in heavy-ion collisions is a long-standing question that has thus far eluded a definitive experimental answer. A crucial complication for quark-gluon discrimination in both proton-proton and heavy-ion collisions is that all measurements necessarily average over the (unknown) quark-gluon composition of a jet sample. In the heavy-ion context, the simultaneous modification of both the fractions and substructure of quark and gluon jets by the quark-gluon plasma further obscures the interpretation. Here, we demonstrate a fully data-driven method for separating quark and gluon contributions to jet observables using a statistical technique called topic modeling. Assuming that jet distributions are a mixture of underlying "quark-like" and "gluon-like" distributions, we show how to extract quark and gluon jet fractions and constituent multiplicity distributions as a function of the jet transverse momentum. This proof-of-concept study is based on proton-proton and heavy-ion collision events from the Monte Carlo event generator Jewel with statistics accessible in Run 4 of the Large Hadron Collider. These results suggest the potential for an experimental determination of quark and gluon jet modifications.

    hep-phnucl-thPRC(2021)·31 citations
21. 21*

    Is SMEFT Enough?

    Timothy Cohen🇺🇸 · Nathaniel Craig🇺🇸 · Xiaochuan Lu🇺🇸 · Dave Sutherland🇮🇹

    There are two canonical approaches to treating the Standard Model as an Effective Field Theory (EFT): Standard Model EFT (SMEFT), expressed in the electroweak symmetric phase utilizing the Higgs doublet, and Higgs EFT (HEFT), expressed in the broken phase utilizing the physical Higgs boson and an independent set of Goldstone bosons. HEFT encompasses SMEFT, so understanding whether SMEFT is sufficient motivates identifying UV theories that require HEFT as their low energy limit. This distinction is complicated by field redefinitions that obscure the naive differences between the two EFTs. By reformulating the question in a geometric language, we derive concrete criteria that can be used to distinguish SMEFT from HEFT independent of the chosen field basis. We highlight two cases where perturbative new physics must be matched onto HEFT: (i) the new particles derive all of their mass from electroweak symmetry breaking, and (ii) there are additional sources of electroweak symmetry breaking. Additionally, HEFT has a broader practical application: it can provide a more convergent parametrization when new physics lies near the weak scale. The ubiquity of models requiring HEFT suggests that SMEFT is not enough.

    hep-phJHEP(2021)·168 citations
22. 22*

    Linearized Optimal Transport for Collider Events

    Tianji Cai🇺🇸 · Junyi Cheng🇺🇸 · Katy Craig🇺🇸 · Nathaniel Craig🇺🇸

    We introduce an efficient framework for computing the distance between collider events using the tools of Linearized Optimal Transport (LOT). This preserves many of the advantages of the recently-introduced Energy Mover's Distance, which quantifies the "work" required to rearrange one event into another, while significantly reducing the computational cost. It also furnishes a Euclidean embedding amenable to simple machine learning algorithms and visualization techniques, which we demonstrate in a variety of jet tagging examples. The LOT approximation lowers the threshold for diverse applications of the theory of optimal transport to collider physics.

    hep-phhep-exstat.MLPRD(2020)·38 citations
23. 23*

    Model Building from Asymptotic Safety with Higgs and Flavor Portals

    Gudrun Hiller🇩🇪 · Clara Hormigos-Feliu🇩🇪 · Daniel F. Litim🇬🇧 · Tom Steudtner🇬🇧

    We perform a comprehensive search for Standard Model extensions inspired by asymptotic safety. Our models feature a singlet matrix scalar field, three generations of vector-like leptons, and direct links to the Higgs and flavor sectors via new Yukawa and portal couplings. A novel feature is that the enlarged scalar sector may spontaneously break lepton flavor universality. We provide a complete two-loop renormalization group analysis of the running gauge, Yukawa, and quartic couplings to find ultraviolet fixed points and the BSM critical surface of parameters, $i.e.$ the set of boundary conditions at the TeV scale for which models remain well-behaved and predictive up to the Planck scale without encountering Landau poles or instabilities. This includes templates for asymptotically safe Standard Model extensions which match the measured values of gauge couplings and the Higgs, top, and bottom masses. We further detail the phenomenology of our models covering production, decay, fermion mixing, anomalous magnetic moments, effects from scalar mixing and chiral enhancement, and constraints on model parameters from data. Signatures at proton-proton and lepton colliders such as lepton flavor violation and displaced vertices, and the prospect for electric dipole moments or charged lepton-flavor-violating type processes, are also indicated.

    hep-phPRD(2020)·69 citations
24. 24*

    Resonant Self-Interacting Dark Matter from Dark QCD

    Yu-Dai Tsai🇺🇸 · Robert McGehee🇺🇸 · Hitoshi Murayama🇯🇵

    We present models of resonant self-interacting dark matter in a dark sector with QCD, based on analogies to the meson spectra in Standard Model QCD. For dark mesons made of two light quarks, we present a simple model that realizes resonant self-interaction (analogous to the $\varphi$-K-K system) and thermal freeze-out. We also consider asymmetric dark matter composed of heavy and light dark quarks to realize a resonant self-interaction (analogous to the ${\rm Y}(4S)$-B-B system) and discuss the experimental probes of both setups. Finally, we comment on the possible resonant self-interactions already built into SIMP and ELDER mechanisms while making use of lattice results to determine feasibility.

    hep-phastro-ph.COhep-exhep-thPRL(2022)·88 citations
25. 25*

    Strange Hadron Spectroscopy with Secondary KL Beam in Hall D

    KLF Collaboration: Moskov Amaryan (ODU)🇺🇸 · Mikhail Bashkanov (UoY)🇬🇧 · Sean Dobbs (FSU)🇺🇸 · James Ritman (Ruhr-U.)🇩🇪 · Justin Stevens (W&M)🇺🇸 · Igor Strakovsky (GWU)🇺🇸 · Shankar Adhikari (ODU)🇺🇸 · Arshak Asaturyan (YerPhi)🇦🇲 · Alexander Austregesilo (JLab)🇺🇸 · Marouen Baalouch (C.E.A.)🇺🇸 · Vitaly Baturin (ODU)🇺🇸 · Vladimir Berdnikov (CUA)🇺🇸 and 140 other authors

    We propose to create a secondary beam of neutral kaons in Hall D at Jefferson Lab to be used with the GlueX experimental setup for strange hadron spectroscopy. The superior CEBAF electron beam will enable a flux on the order of $1\times 10^4{K}_L/sec$, which exceeds the flux of that previously attained at SLAC by three orders of magnitude. The use of a deuteron target will provide first measurements ever with neutral kaons on neutrons. The experiment will measure both differential cross sections and self-analyzed polarizations of the produced $\Lambda$, $\Sigma$, $\Xi$, and $\Omega$ hyperons using the GlueX detector at the Jefferson Lab Hall D. The measurements will span CM $\cos \theta$ from $-0.95$ to 0.95 in the range W = 1490 MeV to 2500 MeV. The new data will significantly constrain the partial wave analyses and reduce model-dependent uncertainties in the extraction of the properties and pole positions of the strange hyperon resonances, and establish the orbitally excited multiplets in the spectra of the $\Xi$ and $\Omega$ hyperons. Comparison with the corresponding multiplets in the spectra of the charm and bottom hyperons will provide insight into he accuracy of QCD-based calculations over a large range of masses. The proposed facility will have a defining impact in the strange meson sector through measurements of the final state $K\pi$ system up to 2 GeV invariant mass. This will allow the determination of pole positions and widths of all relevant $K^{\ast }(K\pi )$ $S$-,$P$-,$D$-,$F$-, and $G$-wave resonances, settle the question of the existence or nonexistence of scalar meson $\kappa /K_0^{\ast }(700)$ and improve the constrains on their pole parameters. Subsequently improving our knowledge of the low-lying scalar nonet in general.

    ↳ nucl-exhep-exhep-phnucl-th72 citations
26. 26*

    On Lorentz-invariant 2D equations admitting long-lived localized solutions with a nontrivial structure

    R.K. Salimov🇷🇺 · T.R.Salimov🇷🇺 · E.G. Ekomasov🇷🇺

    The article studies Lorentz-invariant 2D equations with long-lived ($t\backsim 1000$ ) localized solutions. In the case of three scalar fields localized solutions with a nontrivial internal structure similar to the hadron structure are showed. In this case, the solutions of the equations are analogous to the confinement model by flux tube.

    ↳ nlin.PShep-phPisma Zh.Eksp.Teor.Fiz.(2020)·1 citation
27. 27*

    Constraints on the deformation scale of a geometry in the cotangent bundle

    J.J. Relancio🇪🇸 · S. Liberati🇮🇹

    There are several studies proposing phenomenological consequences of a deformation of special and general relativity. Here, we cast novel constraints on the deformation parameter of a metric in the cotangent bundle accounting for a curved momentum space. In an expanding universe, we study three possible observations that could restrict our model, focusing on the deformations of velocity, redshift and luminosity distance, which in the aforementioned framework, depend on the energy of the particles. We find that for an energy dependent velocity there would be no time delay for massless particles since also the observed distance to the source depends on the energy. For the redshift and luminosity distance we see that a scale of the order of some keV could be compatible with our model. This shows that the constraints on the high-energy scale parametrizing the momentum dependent deviation from a Friedmann-Robertson-Walker metric are at the moment weak due to the fact that the precision (rather than energies) needed in the observational constraints are extremely high. However, this is not the case when considering the synchrotron radiation. Indeed, the observation of such emission from the Crab Nebula, for deformations leading to subluminal propagation at high energies, leads to a constraint for the high-energy scale of the order of 1 PeV.

    ↳ gr-qchep-phPRD(2020)·18 citations
28. 28*

    Charged rho superconductor in the presence of magnetic field and rotation

    Gaoqing Cao🇨🇳

    In this work, we mainly explore the possibility of charged rho superconductor (CRS) in the presence of parallel magnetic field and rotation within three-flavor Nambu--Jona-Lasino model. By following similar schemes as in the previous studies of charged pion superfluid (CPS), the CRS is found to be favored for both choices of Schwinger phase in Minkovski and curved spaces. Due to the stability of the internal spin structure, charged rho begins to condensate at a smaller threshold of angular velocity than charged pion for the given large magnetic fields. Even the axial vector meson condensation is checked -- the conclusion is that CRS is the robust ground state at strong magnetic field and fast rotation, which actually sustains to very large angular velocity.

    ↳ nucl-thhep-phEPJC(2021)·20 citations
29. 29*

    Elimination of the Blue Loops in the Evolution of Intermediate-mass Stars by the Neutrino Magnetic Moment and Large Extra Dimensions

    Kanji Mori🇯🇵 · A. Baha Balantekin🇺🇸 · Toshitaka Kajino🇯🇵 · Michael A. Famiano🇺🇸

    For searching beyond Standard Model physics, stars are laboratories which complement terrestrial experiments. Massless neutrinos in the Standard Model of particle physics cannot have a magnetic moment, but massive neutrinos have a finite magnetic moment in the minimal extension of the Standard Model. Large extra dimensions are a possible solution of the hierarchy problem. Both of these provide additional energy loss channels in stellar interiors via the electromagnetic interaction and radiation into extra dimensions, respectively, and thus affect stellar evolution. We perform simulations of stellar evolution with such additional energy losses and find that they eliminate the blue loops in the evolution of intermediate-mass stars. The existence of Cepheid stars can be used to constrain the neutrino magnetic moment and large extra dimensions. In order for Cepheids to exist, the neutrino magnetic moment should be smaller than the range ~2x10^{-10} to 4x10^{-11}mu_B, where mu_B is the Bohr magneton, and the fundamental scale in the (4+2)-spacetime should be larger than ~2 to 5 TeV, depending on the rate of the ^{12}C(alpha, gamma)^{16}O reaction. The fundamental scale also has strong dependence on the metallicity. This value of the magnetic moment is in the range explored in the reactor experiments, but higher than the limit inferred from globular clusters. Similarly the fundamental scale value we constrain corresponds to a size of the compactified dimensions comparable to those explored in the torsion balance experiments, but is smaller than the limits inferred from collider experiments and low-mass stars.

    ↳ astro-ph.SRhep-phApJ(2020)·9 citations
30. 30*

    Cannibalism hinders growth: Cannibal Dark Matter and the $S_8$ tension

    Stefan Heimersheim🇬🇧 · Nils Schöneberg🇩🇪 · Deanna C. Hooper🇧🇪 · Julien Lesgourgues🇩🇪

    Many models of dark matter have been proposed in attempt to ease the $S_8$ tension between weak lensing and CMB experiments. One such exciting possibility is cannibalistic dark matter (CanDM), which has exothermal number-changing interactions allowing it to stay warm far into its non-relativistic regime. Here we investigate the cosmological implications of CanDM and how it impacts CMB anisotropies and the matter power spectrum, by implementing the model within a linear Einstein-Boltzmann solver. We show that CanDM suppresses the small scale matter power spectrum in a way very similar to light Warm Dark Matter or Hot Dark Matter. However, unlike in those models, the suppression may happen while the CanDM model still remains compatible with CMB constraints. We put strong constraints on the interaction strength of CanDM as a function of its abundance for both constant and temperature-dependent thermally-averaged cross sections. We find that the CanDM model can easily solve the $S_8$ tension (but has no impact on the Hubble tension). Indeed, it can accommodate values of $S_8$ of the order of 0.76 while being compatible with CMB+BAO data. However, as long as the $S_8$ tension remains moderate, the overall ${\chi }^2$ improvement is relatively small given the number of extra free parameters, and the CanDM model is not significantly preferred.

    ↳ astro-ph.COhep-phJCAP(2020)·52 citations
31. 31*

    Beyond special relativity and the notion of spacetime

    J.J. Relancio🇪🇸

    In this Ph.D. thesis several topics in doubly special relativity are explored. The starting point of this theory is very different from other perspectives: it is not a fundamental theory, but it is considered a low energy limit of a quantum gravity theory that tries to study its possible residual elements. In particular, in doubly special relativity the Einstenian relativity principle is generalized, adding to the speed of light $c$ another relativistic invariant, the Planck length $l_p$. This idea can really have possible experimental observations, giving place to what is known as quantum gravity phenomenology. On the other hand, doubly special relativity implies the existence of deformed composition laws for energy and momentum, which leads to a spacetime with nonlocal ingredients, an element that also appears in other approaches of quantum gravity. In particular in this thesis we consider: the role that the changes of momentum variables play in a deformed relativistic kinematics; a novel connection between the $\kappa$-Poincaré model and a curved momentum space; a new spacetime, which turns out to be noncommutative, making the interactions local; the possible time delay in the flight of photons as a consequence of a deformed kinematics, depending on whether observables are defined on a commutative or on a noncommutative spacetime; some computations in quantum field theory with a simple ansatz for the modified Feynman rules corresponding to a particle process; the generalization of the geometrical approach for a curved spacetime.

    ↳ hep-thgr-qchep-ph0 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.