Wed·May 26, 2021Wednesday·May 26, 2021

1. 01*

   Probing the spin correlations of $t\bar{t}$ production at NLO QCD+EW

   Rikkert Frederix🇸🇪 · Ioannis Tsinikos🇸🇪 · Timea Vitos🇸🇪

   In this work we investigate the NLO QCD+EW corrections to the top quark pair production and their effects on the spin correlation coefficients and asymmetries at fixed-order top quark pair production and LO decay in the dilepton channel, within the narrow-width approximation. The spin correlations are implicitly measured through the lepton kinematics. Moreover we study the EW effects to the leptonic differential distributions. We find that the EW corrections to the $t\bar{t}$ production are within the NLO QCD theoretical uncertainties for the spin correlation coefficients and the leptonic asymmetries. On the other hand, for the differential distributions we find that the EW corrections exceed the NLO QCD scale uncertainty band in the high rapidity regimes and are of the order of the NLO QCD scale uncertainty in the case of invariant mass and transverse momentum distributions.

   hep-phEPJC(2021)·25 citations
2. 02*

   Measuring Higgs Boson Self-couplings with $2\to 3$ VBS Processes

   Junmou Chen🇨🇳 · Chih-Ting Lu🇰🇷 · Yongcheng Wu🇺🇸

   We study the measurement of Higgs boson self-couplings through $2\to 3$ vector boson scattering (VBS) processes in the framework of Standard Model effective field theory (SMEFT) at both proton and lepton colliders. The SMEFT contribution to the amplitude of the $2\to 3$ VBS processes, taking $W_L{W}_L\to W_L{W}_{L}h$ and $W_L{W}_L\to hhh$ as examples, exhibits enhancement with the energy $\frac{{\mathcal{A}}^{\text{BSM}}}{{\mathcal{A}}^{\text{SM}}}\sim \frac{E^2}{{\Lambda }^2}$, which indicates the sensitivity of these processes to the related dimension-six operators in SMEFT. Simulation of the full processes at both hadron and lepton colliders with a variety of collision energies are performed to estimate the allowed region on $c_6$ and $c_{{\Phi }_1}$. Especially we find that, with the help of exclusively choosing longitudinal polarizations in the final states and suitable $p_T$ cuts, $WWh$ process is as important as the more widely studied triple Higgs production ($hhh$) in the measurement of Higgs self-couplings. Our analysis indicates that these processes can play important roles in the measurement of Higgs self-couplings at future 100 TeV pp colliders and muon colliders. However, their cross sections are generally tiny at low energy machines, which makes them much more challenging to explore.

   hep-phJHEP(2021)·19 citations
3. 03*

   Fermionic corrections to quark and gluon form factors in four-loop QCD

   Roman N. Lee🇷🇺 · Andreas von Manteuffel🇺🇸 · Robert M. Schabinger🇺🇸 · Alexander V. Smirnov🇷🇺 · Vladimir A. Smirnov🇷🇺 · Matthias Steinhauser🇩🇪

   We analytically compute all four-loop QCD corrections to the photon-quark and Higgs-gluon form factors involving a closed massless fermion loop. Our calculation of non-planar vertex integrals confirms a previous conjecture for the analytical form of the non-fermionic contributions to the collinear anomalous dimensions of quarks and gluons.

   hep-phhep-thPRD(2021)·28 citations
4. 04*

   Gauge invariance of meson photo- and electroproduction currents revisited

   Helmut Haberzettl🇺🇸

   An exact expression is derived for the meson production current off the nucleon for real and virtual photons which cleanly separates, in a model-independent manner, a tree-level expression that manifestly preserves local gauge invariance in terms of a generalized Ward-Takahashi identity from transverse final-state-interaction (FSI) terms. As discussed in some detail, this exact formulation is particularly well suited for implementing approximation schemes of exchange-current and FSI contributions (which in practice generally will be necessary) at any level of sophistication without violating local gauge invariance.

   hep-phnucl-thPRD(2021)·8 citations
5. 05*

   Electroweak Dark Matter

   Ramtin Amintaheri🇦🇺

   In the absence of any hints of new physics in LHC, TeV dark matter candidates interacting through electroweak force (EWDM) are still highly motivated. We extend the Standard Model by adding an arbitrary SU(2) DM multiplet in non-chiral representation. In addition to the well-known real representation which has no coupling to the nuclei at tree level, the complex representation can lead to a new DM candidate providing that one includes a higher dimensional mass-splitting operator, which survives the current direct detection bounds. Since the masses of gauge mediators are light compared to the dark particles, Sommerfeld effect is dominant and affects the value of annihilation cross-section in both the early universe and current time. We computed the relic abundance through freeze-out mechanism in order to determine DM mass. Gamma ray fluxes in our galaxy and dwarf satellites provide a promising tool to probe EWDM theory. We confronted the four fermionic representations of the model with the latest astrophysical observations. It can be concluded that the model passes the current experimental constraints successfully, and it is accessible to future observations.

   hep-phJHEP(2022)·2 citations
6. 06*

   Detectable Gravitational Wave Signals from Affleck-Dine Baryogenesis

   Graham White🇯🇵 · Lauren Pearce🇺🇸 · Daniel Vagie🇺🇸 · Alex Kusenko🇺🇸

   In Affleck-Dine baryogenesis, the observed baryon asymmetry of the Universe is generated through the evolution of the vacuum expectation value (VEV) of a scalar condensate. This scalar condensate generically fragments into non-topological solitons (Q-balls). If they are sufficiently long-lived, they lead to an early matter domination epoch, which enhances the primordial gravitational wave signal for modes that enter the horizon during this epoch. The sudden decay of the Q-balls into fermions results in a rapid transition from matter to radiation domination, producing a sharp peak in the gravitational wave power spectrum. Avoiding the problem of gravitino over-abundance favours scenarios where the peak frequency of the resonance is within the range of the Einstein Telescope and/or Decigo. Therefore, we show this scenario provides an observable signal, providing a mechanism to test Affleck-Dine baryogenesis.

   hep-phastro-ph.COPRL(2021)·53 citations
7. 07*

   Electroweak effects in $e^{+}{e}^{-}\to ZH$ process

   Andrej Arbuzov (1,2)🇷🇺 · Serge Bondarenko (1)🇷🇺 · Lidia Kalinovskaya (3)🇷🇺 · Renat Sadykov (3)🇷🇺 · Vitaly Yermolchyk (3,4) ((1) Bogoliubov Laboratory of Theoretical Physics, JINR, 141980 Dubna, Moscow region, Russia (2) Dubna State University, Universitetskaya str. 19, 141982 Dubna, Russia (3) Dzhelepov Laboratory of Nuclear Problems, JINR, 141980 Dubna, Moscow region, Russia (4) Institute for Nuclear Problems, Belarusian State University, Minsk, 220006 Belarus)🇷🇺

   Electroweak radiative corrections to the cross section of the process $e^{+}{e}^{-}\to ZH$ are considered. The complete one-loop electroweak radiative corrections are evaluated with the help of the SANC system. Higher-order contributions of the initial state radiation are computed in the QED structure function formalism. Numerical results are produced by a new version of the ReneSANCe event generator and MCSANCee integrator for the conditions of future electron-positron colliders. The resulting theoretical uncertainty in the description of this process is estimated.

   hep-ph0 citations
8. 08*

   Rise and fall of laser-intensity effects in spectrally resolved Compton process

   Uwe Hernandez Acosta🇩🇪 · Alexander I. Titov🇷🇺 · Burkhard Kämpfer🇩🇪

   The spectrally resolved differential cross section of Compton scattering, $d\sigma /d{\omega }^{\prime }{|}_{{\omega }^{\prime }=const}$, rises from small towards larger laser intensity parameter $\xi$, reaches a maximum, and falls towards the asymptotic strong-field region. Expressed by invariant quantities: $d\sigma /du{|}_{u=const}$ rises from small towards larger values of $\xi$, reaches a maximum at ${\xi }_{max}=\frac{4}{9}\mathcal{K}u{m}^2/k\cdot p$, $\mathcal{K}=\mathcal{O}(1)$, and falls at $\xi >{\xi }_{max}$ like $\propto {\xi }^{-3/2}\exp \left(-\frac{2u{m}^2}{3\xi k\cdot p}\right)$ at $u\ge 1$. [The quantity $u$ is the Ritus variable related to the light-front momentum-fraction $s=(1+u)/u=k\cdot k^{\prime }/k\cdot p$ of the emitted photon (four-momentum $k^{\prime }$, frequency ${\omega }^{\prime }$), and $k\cdot p/m^2$ quantifies the invariant energy in the entrance channel of electron (four-momentum $p$, mass $m$) and laser (four-wave vector $k$).] Such a behavior of a differential observable is to be contrasted with the laser intensity dependence of the total probability, ${\lim }_{\chi =\xi k\cdot p/m^2,\xi \to \infty }\mathbb{P}\propto \alpha {\chi }^{2/3}{m}^2/k\cdot p$, which is governed by the soft spectral part. We combine the hard-photon yield from Compton with the seeded Breit-Wheeler pair production in a folding model and obtain a rapidly increasing $e^{+}{e}^{-}$ pair number at $\xi \lesssim 4$. Laser bandwidth effects are quantified in the weak-field limit of the related trident pair production.

   hep-phNew J.Phys.(2021)·6 citations
9. 09*

   Inconsistency of the data on the $K_1(1270)\to \pi K_0^{\ast }(1430)$ decay width

   L. Roca🇪🇸 · W. H. Liang🇨🇳 · E. Oset🇪🇸

   We show, using the same Lagrangian for the $K_1(1270)\to \pi K_0^{\ast }(1430)$ and $K_0^{\ast }(1430)\to K_1(1270)\pi$ decays, that the present PDG data on the partial decay width of $K_1(1270)\to \pi K_0^{\ast }(1430)$ implies a width for $K_0^{\ast }(1430)\to K_1(1270)\pi$ decay which is about ten times larger than the total $K_0^{\ast }(1430)$ width. A discussion on this inconsistency is done, stressing its relationship to the existence of two $K_1(1270)$ states obtained with the chiral unitary theory, which are not considered in the experimental analyses of $K\pi \pi$ data.

   hep-phPLB(2022)·5 citations
10. 10*

    Effect of large light-heavy neutrino mixing and natural type-II seesaw dominance to lepton flavor violation and neutrinoless double beta decay

    Nitali Dash (NCERT, BBSR)🇮🇳 · Sudhanwa Patra (IIT Bhilai)🇮🇳 · Prativa Pritimita (IIT Bombay)🇮🇳 · Urjit A. Yajnik (IIT Bombay)🇮🇳

    We derive the lower bound on the absolute scale of lightest neutrino mass for normal hierarchy and inverted hierarchy pattern of light neutrinos by studying the new physics contributions to charged lepton flavour violations in the framework of a TeV scale left-right symmetric model. In the model, the fermion sector comprises the usual quarks and leptons plus a fermion singlet per generation and the scalar sector consists of isospin doublets, triplets and a bidoublet. The framework allows large light-heavy neutrino mixing where the light neutrino mass formula is governed by a natural type-II seesaw mechanism, unlike the generic type-II seesaw dominance which assumes suppressed light-heavy neutrino mixing. We demonstrate how sizeable loop-induced contribution to light neutrino mass is kept under control such that the light neutrino mass formula is dominantly explained by the type-II seesaw mechanism. We examine the heavy neutrino contributions with large light-heavy neutrino mixing to charged lepton flavour violating processes like $\mu \to e\gamma$, $\mu \to 3e$ and $\mu \to e$ conversion inside a nucleus. We present a complementary study between neutrinoless double beta decay and charged lepton flavour violation taking into account single beta decay bound, double beta decay bound and cosmology bounds on the sum of light neutrino masses.

    hep-phEPJC(2022)·3 citations
11. 11*

    Dark photon portal into mirror world

    Abdaljalel Alizzi🇷🇺 · Z.K. Silagadze🇷🇺

    Dark photons and mirror matter are well-motivated dark matter candidates. It is possible that both of them arose during the compactification and symmetry breaking scenario of the heterotic $E_8\times E_8$ string theory and are related to each other. In this case, dark photons can become a natural portal into the mirror world. Unfortunately, the expected magnitude of the induced interactions of ordinary matter with mirror matter is too small to be of phenomenological interest.

    hep-phMod.Phys.Lett.A(2021)·9 citations
12. 12*

    Electroweak phase transition in a complex singlet extension of the Standard Model with degenerate scalars

    Gi-Chol Cho🇯🇵 · Chikako Idegawa🇯🇵 · Eibun Senaha🇻🇳

    We study the feasibility of strong first-order electroweak phase transition (EWPT) in a degenerate-scalar scenario of a complex singlet extension of the Standard Model, in which a mass of an additional scalar is nearly degenerate with that of the Higgs boson, 125 GeV. This scenario is known to provide an exquisite solution for circumventing constraints from dark matter direct detection experiments due to cancellations between two scattering amplitudes mediated by two scalars. In the analysis of EWPT, we employ two gauge-invariant calculation schemes on the scalar potential and two familiar resummation methods in evaluating one-loop (gauge dependent) effective potential. We point out that one of the conditions for the strong first-order EWPT is incompatible with the known suppression mechanism of a dark matter cross-section scattering off the nucleons. Nevertheless, we find that strong first-order EWPT is still possible in the degenerate-scalar scenario by dodging dark matter constraints differently.

    hep-phPLB(2021)·35 citations
13. 13*

    Anatomy of a new anomaly in non-leptonic B decays

    M. Algueró🇪🇸 · A. Crivellin🇨🇭 · S. Descotes-Genon🇫🇷 · J. Matias🇪🇸 · M. Novoa-Brunet🇫🇷

    We discuss the anatomy of the $L_{VV}$ observable designed as a ratio of the longitudinal components of $B_s\to VV$ versus $B_d\to VV$ decays. We focus on the particular case of $B_{d,s}\to K^{\ast 0}{\bar{K}}^{\ast 0}$ where we find for the SM prediction $L_{K^{\ast }{\bar{K}}^{\ast }}=19.5_{-6.8}^{+9.3}$ implying a 2.6$\sigma$ tension with respect to data. The interpretation of this tension in a model independent way identifies two Wilson coefficients ${\mathcal{C}}_4$ and ${\mathcal{C}}_{8g}$ as possible sources. The example of one simplified model including a Kaluza-Klein (KK) gluon is discussed. This KK gluon embedded inside a composite/extra dimensional model combined with a $Z^{\prime }$ can explain also the $b\to s\ell \ell$ anomalies albeit with a significant amount of fine-tuning.

    hep-phhep-ex1 citation
14. 14*

    The structure of the X(3872) as explained by a Diffusion Monte Carlo calculation

    M.C. Gordillo🇪🇸 · F. De Soto🇪🇸 · J. Segovia🇪🇸

    Two decades after its unexpected discovery, the properties of the $X(3872)$ exotic resonance are still under intense scrutiny. In particular, there are doubts about its nature as an ensemble of mesons or having any other internal structure. We use a Diffusion Monte Carlo method to solve the many-body Schrödinger equation that describes this state as a $c\bar{c}n\bar{n}$ ($n=u$ or $d$ quark) system. This approach accounts for multi-particle correlations in physical observables avoiding the usual quark-clustering assumed in other theoretical techniques. The most general and accepted pairwise Coulomb$+$linear-confining$+$hyperfine spin-spin interaction, with parameters obtained by a simultaneous fit of around 100 masses of mesons and baryons, is used. The $X(3872)$ contains light quarks whose masses are given by the mechanism responsible of the dynamical breaking of chiral symmetry. The same mechanisms gives rise to Goldstone-boson exchange interactions between quarks that have been fixed in the last 10-20 years reproducing hadron, hadron-hadron and multiquark phenomenology. It appears that a meson-meson molecular configuration is preferred but, contrary to the usual assumption of $D^0{\bar{D}}^{\ast 0}$ molecule for the $X(3872)$, our formalism produces $\omega J/\psi$ and $\rho J/\psi$ clusters as the most stable ones, which could explain in a natural way all the observed features of the $X(3872)$.

    hep-phhep-exhep-latnucl-ex+1PRD(2021)·16 citations
15. 15*

    Towards a method to anticipate dark matter signals with deep learning at the LHC

    Ernesto Arganda🇪🇸 · Anibal D. Medina🇦🇷 · Andres D. Perez🇦🇷 · Alejandro Szynkman🇦🇷

    We study several simplified dark matter (DM) models and their signatures at the LHC using neural networks. We focus on the usual monojet plus missing transverse energy channel, but to train the algorithms we organize the data in 2D histograms instead of event-by-event arrays. This results in a large performance boost to distinguish between standard model (SM) only and SM plus new physics signals. We use the kinematic monojet features as input data which allow us to describe families of models with a single data sample. We found that the neural network performance does not depend on the simulated number of background events if they are presented as a function of $S/\sqrt{B}$, where $S$ and $B$ are the number of signal and background events per histogram, respectively. This provides flexibility to the method, since testing a particular model in that case only requires knowing the new physics monojet cross section. Furthermore, we also discuss the network performance under incorrect assumptions about the true DM nature. Finally, we propose multimodel classifiers to search and identify new signals in a more general way, for the next LHC run.

    hep-phcs.LGhep-exSciPost Phys.(2022)·11 citations
16. 16*

    $B_c$ meson exclusive decays to a $P$-wave charmonium and a pion at NLO accuracy

    Zi-Qiang Chen🇨🇳 · Cong-Feng Qiao🇨🇳

    In this paper, we calculate the next-to-leading order (NLO) quantum chromodynamics (QCD) corrections to the exclusive processes $B_c^{+}\to {\chi }_{cJ}(h_c){\pi }^{+}$ in the framework of the nonrelativistic QCD (NRQCD) factorization formalism. The results show that NLO QCD corrections markedly enhance the branching ratios with $K$ factors of about 2.5. In combination with the study of $B_c^{+}\to J/\psi {\pi }^{+}$, we find that the NLO NRQCD prediction for the ratio of branching fractions $\frac{\mathcal{B}(B_c^{+}\to {\chi }_{c0}{\pi }^{+})}{\mathcal{B}(B_c^{+}\to J/\psi {\pi }^{+})}$ is then compatible with the experimental measurement.

    hep-phPRD(2021)·6 citations
17. 17*

    Two-photon exchange in leptophilic dark matter scenarios

    Raghuveer Garani (INFN Florence)🇮🇹 · Federico Gasparotto🇮🇹 · Pierpaolo Mastrolia🇮🇹 · Henrik J. Munch (Padua U. and INFN, Padua)🇮🇹 · Sergio Palomares-Ruiz (IFIC, CSIC-Valencia U.)🇪🇸 · Amedeo Primo (Zurich U.)🇨🇭

    In leptophilic scenarios, dark matter interactions with nuclei, relevant for direct detection experiments and for the capture by celestial objects, could only occur via loop-induced processes. If the mediator is a scalar or pseudo-scalar particle, which only couples to leptons, the dominant contribution to dark matter-nucleus scattering would take place via two-photon exchange with a lepton triangle loop. The corresponding diagrams have been estimated in the literature under different approximations. Here, we present new analytical calculations for one-body two-loop and two-body one-loop interactions. The two-loop form factors are presented in closed analytical form in terms of generalized polylogarithms up to weight four. In both cases, we consider the exact dependence on all the involved scales, and study the dependence on the momentum transfer. We show that some previous approximations fail to correctly predict the scattering cross section by several orders of magnitude. Moreover, we show that form factors, in the range of momentum transfer relevant for local galactic dark matter, are smaller than their value at zero momentum transfer, which is usually considered.

    hep-phhep-thJHEP(2021)·8 citations
18. 18*

    Gravitational Wave Echo of Relaxion Trapping

    Abhishek Banerjee🇮🇱 · Eric Madge🇮🇱 · Gilad Perez🇮🇱 · Wolfram Ratzinger🇩🇪 · Pedro Schwaller🇩🇪

    To solve the hierarchy problem, the relaxion must remain trapped in the correct minimum, even if the electroweak symmetry is restored after reheating. In this scenario, the relaxion starts rolling again until the backreaction potential, with its set of local minima, reappears. Depending on the time of barrier reappearance, Hubble friction alone may be insufficient to retrap the relaxion in a large portion of the parameter space. Thus, an additional source of friction is required, which might be provided by coupling to a dark photon.The dark photon experiences a tachyonic instability as the relaxion rolls, which slows down the relaxion by backreacting to its motion, and efficiently creates anisotropies in the dark photon energy-momentum tensor, sourcing gravitational waves. We calculate the spectrum of the resulting gravitational wave background from this new mechanism, and evaluate its observability by current and future experiments. We further investigate the possibility that the coherently oscillating relaxion constitutes dark matter and present the corresponding constraints from gravitational waves.

    hep-phastro-ph.COPRD(2021)·29 citations
19. 19*

    EFT at FASER$\nu$

    Adam Falkowski🇫🇷 · Martín González-Alonso🇪🇸 · Joachim Kopp🇨🇭 · Yotam Soreq🇮🇱 · Zahra Tabrizi🇺🇸

    We investigate the sensitivity of the FASER$\nu$ detector to new physics in the form of non-standard neutrino interactions. FASER$\nu$, which has recently been installed 480 m downstream of the ATLAS interaction point, will for the first time study interactions of multi-TeV neutrinos from a controlled source. Our formalism -- which is applicable to any current and future neutrino experiment -- is based on the Standard Model Effective Theory~(SMEFT) and its counterpart, Weak Effective Field Theory~(WEFT), below the electroweak scale. Starting from the WEFT Lagrangian, we compute the coefficients that modify neutrino production in meson decays and detection via deep-inelastic scattering, and we express the new physics effects in terms of modified flavor transition probabilities. For some coupling structures, we find that FASER$\nu$ will be able to constrain interactions that are two to three orders of magnitude weaker than Standard Model weak interactions, implying that the experiment will be indirectly probing new physics at the multi-TeV scale. In some cases, FASER$\nu$ constraints will become comparable to existing limits - some of them derived for the first time in this paper - already with $150$fb${}^{-1}$ of data.

    hep-phhep-exJHEP(2021)·62 citations
20. 20*

    The Race to Find Split Higgsino Dark Matter

    Raymond T. Co🇺🇸 · Benjamin Sheff🇺🇸 · James D. Wells🇺🇸

    Split higgsinos are a compelling class of models to explain dark matter and may be on the verge of detection by multiple current experimental avenues. The idea is based on a large split in scales between the electroweak scale and decoupled scalars, with relatively light higgsinos between the two. Such models enjoy the merit of depending on very few parameters while still explaining gauge coupling unification, dark matter, and most of the hierarchy between the Planck and electroweak scales, and they remain undetected by past experiments. We analyze split higgsinos in view of current and next generation experiments. We discuss the direct and indirect detection prospects and further demonstrate promising discovery potentials in the upcoming electron electric dipole moment experiments. The parameter space of this model is analyzed in terms of experiments expected to run in the coming years and where we should be looking for the next potential discoveries.

    hep-phhep-exPRD(2022)·35 citations
21. 21*

    Ultrahigh-energy Gamma Rays and Gravitational Waves from Primordial Exotic Stellar Bubbles

    Yi-Fu Cai🇨🇳 · Chao Chen🇨🇳 · Qianhang Ding🇨🇳 · Yi Wang🇨🇳

    We put forward a novel class of exotic celestial objects that can be produced through phase transitions occurred in the primordial Universe. These objects appear as bubbles of stellar sizes and can be dominated by primordial black holes (PBHs). We report that, due to the processes of Hawking radiation and binary evolution of PBHs inside these stellar bubbles, both electromagnetic and gravitational radiations can be emitted that are featured on the gamma-ray spectra and stochastic gravitational waves (GWs). Our results reveal that, depending on the mass distribution, the exotic stellar bubbles consisting of PBHs provide not only a decent fit for the ultrahigh-energy gamma-ray spectrum reported by the recent LHAASO experiment, but also predict GW signals that are expected to be tested by the forthcoming GW surveys.

    ↳ astro-ph.COgr-qchep-phhep-thEPJC(2022)·15 citations
22. 22*

    The sound-ring radiation of expanding vortex clusters

    August Geelmuyden🇬🇧 · Sebastian Erne🇬🇧 · Sam Patrick🇨🇦 · Carlo Barenghi🇬🇧 · Silke Weinfurtner🇬🇧

    We investigate wave-vortex interaction emerging from an expanding compact vortex cluster in a two-dimensional Bose-Einstein condensate. We adapt techniques developed for compact gravitational objects to derive the characteristic modes of the wave-vortex interaction perturbatively around an effective vortex flow field. We demonstrate the existence of orbits or sound-rings, in analogy to gravitational light-rings, and compute the characteristic spectrum for the out-of-equilibrium vortex cluster. The spectrum obtained from numerical simulations of a stochastic Gross-Pitaevskii equation exhibiting an expanding vortex cluster is in excellent agreement with analytical predictions. Our findings are relevant for 2d-quantum turbulence, the semi-classical limit around fluid flows, and rotating compact objects exhibiting discrete circulation.

    ↳ gr-qccond-mat.quant-gashep-phhep-th+1PRResearch(2022)·12 citations
23. 23*

    MP3 White Paper 2021 -- Research Opportunities Enabled by Co-locating Multi-Petawatt Lasers with Dense Ultra-Relativistic Electron Beams

    Sebastian Meuren🇺🇸 · David A. Reis🇺🇸 · Roger Blandford🇺🇸 · Phil H. Bucksbaum🇺🇸 · Nathaniel J. Fisch🇺🇸 · Frederico Fiuza🇺🇸 · Elias Gerstmayr🇺🇸 · Siegfried Glenzer🇺🇸 · Mark J. Hogan🇺🇸 · Claudio Pellegrini🇺🇸 · Michael E. Peskin🇺🇸 · Kenan Qu🇺🇸 · Glen White🇺🇸 · Vitaly Yakimenko🇺🇸

    Novel emergent phenomena are expected to occur under conditions exceeding the QED critical electric field, where the vacuum becomes unstable to electron-positron pair production. The required intensity to reach this regime, $\sim 10^{29}\mathrm{Wc}{\mathrm{m}}^{-2}$, cannot be achieved even with the most intense lasers now being planned/constructed without a sizeable Lorentz boost provided by interactions with ultrarelativistic particles. Seeded laser-laser collisions may access this strong-field QED regime at laser intensities as low as $\sim 10^{24}\mathrm{Wc}{\mathrm{m}}^{-2}$. Counterpropagating e-beam--laser interactions exceed the QED critical field at still lower intensities ($\sim 10^{20}\mathrm{Wc}{\mathrm{m}}^{-2}$ at $\sim 10\mathrm{GeV}$). Novel emergent phenomena are predicted to occur in the "QED plasma regime", where strong-field quantum and collective plasma effects play off one another. Here the electron beam density becomes a decisive factor. Thus, the challenge is not just to exceed the QED critical field, but to do so with high quality, approaching solid-density electron beams. Even though laser wakefield accelerators (LWFA) represent a very promising research field, conventional accelerators still provide orders of magnitude higher charge densities at energies $\gtrsim 10\mathrm{GeV}$. Co-location of extremely dense and highly energetic electron beams with a multi-petawatt laser system would therefore enable seminal research opportunities in high-field physics and laboratory astrophysics. This white paper elucidates the potential scientific impact of multi-beam capabilities that combine a multi-PW optical laser, high-energy/density electron beam, and high-intensity x rays and outlines how to achieve such capabilities by co-locating a 3-10 PW laser with a state-of-the-art linear accelerator.

    ↳ physics.plasm-phhep-ph12 citations
24. 24*

    The Higgs-Graviton Couplings: from Amplitudes to the Action

    Allan Alonzo-Artiles🇮🇹 · Ana Avilez-López🇲🇽 · J. Lorenzo Díaz-Cruz🇲🇽 · Bryan O. Larios-López🇭🇳

    In this paper we study the coupling of scalar (Higgs) particles ($\varphi$) with gravitons ($h$) and their possible effects. The general form of the 3-point interaction $\varphi (p)h(1)h(2)$ can be derived using the scaling behavior of the spinor variables under the little group; the resulting vertices exhibit such simplicity, that some simplifications should be hidden in the expressions obtained from the extended scalar action. To investigate this, we study an extended Einstein-Hilbert action that besides the minimal coupling, it also includes terms of the form $\varphi R^2$, $\varphi R^{\mu \nu }{R}_{\mu \nu }$ and $\varphi R^{\mu \nu \rho \sigma }{R}_{\mu \nu \rho \sigma }$, as well as the term ${ϵ}_{\mu \nu \alpha \beta }{\varphi }_5{R}_{\rho \sigma }^{\mu \nu }{R}^{\alpha \beta \rho \sigma }$ for the case of a pseudo-scalar (${\varphi }_5$). The resulting vertices satisfy KLT-type relations, i.e., they can be written as the square of the coupling of the Higgs with gluons. We find that the amplitude for the Higgs decay into a pair of gravitons (on-shell) only receives a contribution coming from the square of the Riemann tensor. Similar results are obtained for the 3-body decay $\varphi \to h{h}^{\ast }(\to XX)$, with an off-shell graviton ($h^{\ast }$) that goes into the final state $XX$. One could expect that these quadratic terms can produce new loop effects, however we find that the new contribution from this non-minimal coupling to the graviton self-energy, also vanishes for on-shell gravitons.

    ↳ hep-thhep-ph8 citations
25. 25*

    Extranatural Flux Inflation

    Takuya Hirose🇯🇵 · Nobuhito Maru🇯🇵

    We propose a new inflation scenario in flux compactification, where a zero mode scalar field of extra components of the higher dimensional gauge field is identified with an inflaton. The scalar field is a pseudo Nambu-Goldstone boson of spontaneously broken translational symmetry in compactified spaces. The inflaton potential is non-local and finite, which is protected against the higher dimensional non-derivative local operators by quantum gravity corrections thanks to the gauge symmetry in higher dimensions and the shift symmetry originated from the translation in extra spaces. We give an explicit inflation model in a six dimensional scalar QED, which is shown to be consistent with Planck 2018 data.

    ↳ hep-thastro-ph.COhep-phJHEP(2021)·5 citations
26. 26*

    Particle detection and tracking with DNA

    Ciaran A. J. O'Hare🇦🇺 · Vassili G. Matsos🇦🇺 · Joseph Newton🇦🇺 · Karl Smith🇦🇺 · Joel Hochstetter🇦🇺 · Ravi Jaiswar🇦🇺 · Wunna Kyaw🇦🇺 · Aimee McNamara🇺🇸 · Zdenka Kuncic🇦🇺 · Sushma Nagaraja Grellscheid🇳🇴 · Celine Boehm🇦🇺

    We present the first proof-of-concept simulations of detectors using biomaterials to detect particle interactions. The essential idea behind a "DNA detector" involves the attachment of a forest of precisely-sequenced single or double-stranded nucleic acids from a thin holding layer made of a high-density material. Incoming particles break a series of strands along a roughly co-linear chain of interaction sites and the severed segments then fall to a collection area. Since the sequences of base pairs in nucleic acid molecules can be precisely amplified and measured using polymerase chain reaction (PCR), the original spatial position of each broken strand inside the detector can be reconstructed with nm precision. Motivated by the potential use as a low-energy directional particle tracker, we perform the first Monte Carlo simulations of particle interactions inside a DNA detector. We compare the track topology as a function of incoming direction, energy, and particle type for a range of ionising particles. While particle identification and energy reconstruction might be challenging without a significant scale-up, the excellent potential angular and spatial resolution ($\lesssim 25^{\circ }$ axial resolution for a keV-scale particles and nm-scale track segments) are clear advantages of this concept. We conclude that a DNA detector could be a cost-effective, portable, and powerful new particle detection technology. We outline the outstanding experimental challenges, and suggest directions for future laboratory tests.

    ↳ physics.ins-dethep-exhep-phEPJC(2022)·13 citations
27. 27*

    The pion-nucleon sigma term from lattice QCD

    Rajan Gupta🇺🇸 · Sungwoo Park🇺🇸 · Martin Hoferichter🇨🇭 · Emanuele Mereghetti🇺🇸 · Boram Yoon🇺🇸 · Tanmoy Bhattacharya🇺🇸

    We present an analysis of the pion-nucleon $\sigma$-term, ${\sigma }_{\pi N}$, using six ensembles with 2+1+1-flavor highly improved staggered quark action generated by the MILC collaboration. The most serious systematic effect in lattice calculations of nucleon correlation functions is the contribution of excited states. We estimate these using chiral perturbation theory ($\chi$PT), and show that the leading contribution to the isoscalar scalar charge comes from N$\pi$ and N$\pi \pi$ states. Therefore, we carry out two analyses of lattice data to remove excited-state contamination, the standard one and a new one including N$\pi$ and N$\pi \pi$ states. We find that the standard analysis gives ${\sigma }_{\pi N}=41.9(4.9)$ MeV, consistent with previous lattice calculations, while our preferred $\chi$PT-motivated analysis gives ${\sigma }_{\pi N}=59.6(7.4)$ MeV, which is consistent with phenomenological values obtained using $\pi$N scattering data. Our data on one physical pion mass ensemble was crucial for exposing this difference, therefore, calculations on additional physical mass ensembles are needed to confirm our result and resolve the tension between lattice QCD and phenomenology.

    ↳ hep-lathep-phnucl-thPRL(2021)·90 citations
28. 28*

    Machine-Learned Dark Matter Subhalo Candidates in the 4FGL-DR2: Search for the Perturber of the GD-1 Stream

    Nestor Mirabal · Ana Bonaca🇺🇸

    The detection of dark matter subhalos without a stellar component in the Galactic halo remains a challenge. We use supervised machine learning to identify high-latitude gamma-ray sources with dark matter-like spectra among unassociated gamma-ray sources in the 4FGL-DR2. Out of 843 4FGL-DR2 unassociated sources at $|b|\ge 10{}^{\circ }$, we select 73 dark matter subhalo candidates. Of the 69 covered by the Neil Gehrels Swift Observatory (Swift), 17 show at least one X-ray source within the 95% LAT error ellipse and 52 where we identify no new sources. This latest inventory of dark subhalos candidates allows us to investigate the possible dark matter substructure responsible for the perturbation in the GD-1 stellar stream. In particular, we examine the possibility that the alleged GD-1 dark subhalo may appear as a 4FGL-DR2 gamma-ray source from dark matter annihilation into Standard Model particles.

    ↳ astro-ph.HEastro-ph.COhep-phJCAP(2021)·14 citations
29. 29*

    A Theory of Giant Vortices

    Alexander A. Penin🇨🇦 · Quinten Weller🇨🇦

    We elaborate a theory of giant vortices [1] based on an asymptotic expansion in inverse powers of their winding number $n$. The theory is applied to the analysis of vortex solutions in the abelian Higgs (Ginzburg-Landau) model. Specific properties of the giant vortices for charged and neutral scalar fields as well as different integrable limits of the scalar self-coupling are discussed. Asymptotic results and the finite-$n$ corrections to the vortex solutions are derived in analytic form and the convergence region of the expansion is determined.

    ↳ hep-thcond-mat.mes-hallhep-phJHEP(2021)·8 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.