Wed·Sep 15, 2021Wednesday·September 15, 2021

1. 01*

   Neutrino interactions in liquid scintillators including active-sterile neutrino mixing

   M.M.Saez🇦🇷 · M.E.Mosquera🇦🇷 · O.Civitarese🇦🇷

   Neutrinos play an important role in core-collapse supernova events since they are a key piece to understand the explosion mechanisms. The analysis of the neutrino fluxes can bring answers to neutrino's related problems e.g.: mass hierarchy, spectral splitting, sterile neutrinos, etc. In this work we study the impact of neutrino oscillations and the possible existence of eV sterile neutrinos upon the supernova neutrino flux $F_{\nu }(E)$. We have calculated the energy distribution of the neutrino flux from a supernova and the total number of events which would be detected in a liquid scintillator. We also present an analysis for the conversion probabilities as a function of the active-sterile neutrino mixing parameters. Finally, we have carried out a statistical analysis to extract values for the mixing parameters of the model.

   hep-phnucl-thIJMPE(2022)·2 citations
2. 02*

   Hadrons as QCD Bound States

   Paul Hoyer🇫🇮

   Bound state perturbation theory is well established for QED atoms. Today the hyperfine splitting of Positronium is known to $O({\alpha }^7\log \alpha )$. Whereas standard expansions of scattering amplitudes start from free states, bound states are expanded around eigenstates of the Hamiltonian including a binding potential. The eigenstate wave functions have all powers of $\alpha$, requiring a choice in the ordering of the perturbative expansion. Temporal $(A^0=0)$ gauge permits an expansion starting from valence Fock states, bound by their instantaneous gauge field. This formulation is applicable in any frame and seems promising even for hadrons in QCD. The $O({\alpha }_s^0)$ confining potential is determined (up to a universal scale) by a homogeneous solution of Gauss' law.

   hep-phnucl-thEPJ Web Conf.(2022)·0 citations
3. 03*

   Machine-learning-based identification for initial clustering structure in relativistic heavy-ion collisions

   Junjie He🇨🇳 · Wan-Bing He🇨🇳 · Yu-Gang Ma🇨🇳 · Song Zhang🇨🇳

   $\alpha$-clustering structure is a significant topic in light nuclei. A Bayesian convolutional neural network (BCNN) is applied to classify initial non-clustered and clustered configurations, namely Woods-Saxon distribution and three-$\alpha$ triangular (four-$\alpha$ tetrahedral) structure for ${}^{12}$C (${}^{16}$O), from heavy-ion collision events generated within a multi-phase transport (AMPT) model. Azimuthal angle and transverse momentum distributions of charged pions are taken as inputs to train the classifier. On multiple-event basis, the overall classification accuracy can reach $95\%$ for ${}^{12}$C/${}^{16}$O + ${}^{197}$Au events at $\sqrt{S_{NN}}=$ 200 GeV. With proper constructions of samples, the predicted deviations on mixed samples with different proportions of both configurations could be within $5\%$. In addition, setting a simple confidence threshold can further improve the predictions on the mixed dataset. Our results indicate promising and extensive possibilities of application of machine-learning-based techniques to real data and some other problems in physics of heavy-ion collisions.

   hep-phnucl-exnucl-thPRC(2021)·38 citations
4. 04*

   Nambu-Jona-Lasinio model correlation functions from QCD

   Marco Frasca🇮🇹 · Anish Ghoshal🇮🇹 · Stefan Groote🇪🇪

   We treat quantum chromodynamics (QCD) using a set of Dyson-Schwinger equations derived, in differential form, with the Bender-Milton-Savage technique. In this way, we are able to derive the low energy limit that assumes the form of a non-local Nambu-Jona-Lasinio model with all the parameters properly fixed by the QCD Lagrangian and the determination of the mass gap of the gluon sector.

   hep-phNucl.Part.Phys.Proc.(2022)·12 citations
5. 05*

   Fermion propagator diagonalization and eigenvalue problem

   D.A. Dolzhikov (1)🇷🇺 · A.E. Kaloshin (1 and 2)🇷🇺 · V.P. Lomov (2 and 3) ((1) Joint Institute for Nuclear Research, (2) Irkutsk State University, (3) Institute for System Dynamics and Control Theory)🇷🇺

   We discuss diagonalization of propagator for mixing fermions system based on the eigenvalue problem. The similarity transformation converting matrix propagator into diagonal form is obtained. The suggested diagonalization has simple algebraic properties for on-shell fermions and can be used in renormalization of fermion mixing matrix.

   hep-phhep-thMod.Phys.Lett.A(2022)·0 citations
6. 06*

   Dark Matter Axions, Non-Newtonian Gravity and Constraints on them from Recent Measurement of the Casimir Force in the Micrometer Separation Range

   Galina L. Klimchitskaya🇷🇺 · Vladimir M. Mostepanenko🇷🇺

   We consider axionlike particles, as the most probable constituents of dark matter, the Yukawa-type corrections to Newton's gravitational law and constraints on their parameters following from astrophysics and different laboratory experiments. After a brief discussion of the results by Prof. Yu. N. Gnedin in this field, we are coming to the recent experiment on measuring the differential Casimir force between Au-coated surfaces of a sphere and the top and bottom of rectangular trenches. In this experiment, the Casimir force was measured over an unusually wide separation region from 0.2 to 8~mcm and compared with the exact theory based on first principles of quantum electrodynamics at nonzero temperature. We use the measure of agreement between experiment and theory for obtaining constraints on the coupling constant of axionlike particles to nucleons and on the interaction strength of Yukawa-type interaction. The obtained constraints on the axion-to-nucleon coupling constant and on the strength of Yukawa interaction are stronger by the factors of 4 and 24, respectively, than those found previously from gravitational experiments and measurements of the Casimir force, but weaker than the constraints following from the differential measurement where the Casimir force was nullified. Some other already performed and planned experiments directed to the search of axions and non-Newtonian gravity are discussed and their prospects are evaluated.

   hep-phUniverse·16 citations
7. 07*

   Full solution of the medium-induced radiation spectrum

   Carlota Andres🇺🇸 · Liliana Apolinario🇵🇹 · Fabio Dominguez🇪🇸

   New measurements of jet quenching observables at RHIC and at the LHC, such as jet substructure observables, demand an increased precision in the theory calculations describing medium-induced radiation of gluons. Closed expressions for the gluon spectrum including a full resummation of multiple scatterings have been known for the past 20 years. Still they have only been evaluated in specific limits either taking a few terms in an opacity expansion or by employing a Gaussian approximation for the interaction potential -- which misses essential physical effects. We present here a new flexible method to compute the full spectrum for a realistic interaction potential, thus allowing us for the first time to properly quantify the effect of the all-order resummation of multiple scatterings. This new approach paves the way for precision phenomenological studies including multiple scattering effects such as coherence phenomena.

   hep-phnucl-thPoS(2021)·0 citations
8. 08*

   Light unflavor vector meson spectroscopy around the mass range of $2.4\sim 3$ GeV and possible experimental evidence

   Li-Ming Wang🇨🇳 · Si-Qiang Luo🇨🇳 · Xiang Liu🇨🇳

   In this work, we predict the spectroscopy behavior of these light unflavored vector mesons with masses at the range of $2.4\sim 3$ GeV, which are still missing in the experiment. By presenting their mass spectrum and studying their two-body Okubo-Zweig-lizuka allowed decay widths, we discuss the possible experimental evidences of these discussed states combining with the present experimental data. Especially, we strongly suggest that our experimental colleagues carry out the exploration of these higher states via the $e^{+}{e}^{-}$ annihilation into light mesons. It is obvious that BESIII and Belle II will be potential experiments to achieve this target.

   hep-phhep-exPRD(2022)·27 citations
9. 09*

   SU(2,1) / (SU(2) x U(1)) B-L Higgs Inflation

   C Pallis🇬🇷

   We present a realization of Higgs inflation within Supergravity which is largely tied to the existence of a pole of order two in the kinetic term of the inflaton field. This pole arises due to the selected Kaehler potential which parameterizes the SU(2,1) / (SU(2) x U(1)) manifold with scalar curvature R_{21}=-6/N. The associated superpotential includes, in addition to the Higgs superfields, a stabilizer superfield, respects a B-L gauge and an R symmetries and contains the first allowed nonrenormalizable term. If the coefficient of this term is almost equal to that of the others within about 10^-5 and N=2, the inflationary observables can be done compatible with the present data. The tuning can be eluded if we modify the Kaehler potential associated with the manifold above. In this case, inflation can be realized with just renormalizable superpotential terms and results to higher tensor-to-scalar ratios as N approaches its maximum at N~80.

   hep-phastro-ph.COhep-thJ.Phys.Conf.Ser.(2021)·5 citations
10. 10*

    Quantum nature of the minimal potentially realistic $\mathrm{SO}(10)$ Higgs model

    Kateřina Jarkovská🇨🇿 · Michal Malinský🇨🇿 · Timon Mede🇸🇮 · Vasja Susič🇨🇭

    We study several aspects of the quantum structure of the minimal potentially realistic renormalizable $\mathrm{SO}(10)$ Higgs model in which the $45\oplus 126$ scalars spontaneously break the symmetry down to the Standard Model group $\mathrm{SU}(3{)}_c\times \mathrm{SU}(2{)}_L\times \mathrm{U}(1{)}_Y$. With a complete information about the one-loop corrections to the masses of all scalars in the theory and the one-loop beta functions governing the running of all dimensionless scalar self-couplings, the domains of the parameter space where the model can be treated perturbatively are established, along with improved bounds from the requirements of the SM vacuum stability and gauge coupling unification. We demonstrate that the model is fully consistent and potentially realistic only in very narrow regions of the parameter space corresponding to the breaking chains with well pronounced $\mathrm{SU}(4{)}_C\times \mathrm{SU}(2{)}_L\times \mathrm{U}(1{)}_R$ and $\mathrm{SU}(3{)}_c\times \mathrm{SU}(2{)}_L\times \mathrm{SU}(2{)}_R\times \mathrm{U}(1{)}_{B-L}$ intermediate symmetries, with a clear preference for the former case. Barring accidental fine-tunings in the scalar sector, this makes it possible to provide a very sharp prediction for the position of the unification scale and the value of the associated gauge coupling, with clear implications for the phenomenology of grand unified models based on this structure.

    hep-phPRD(2022)·20 citations
11. 11*

    Measuring neutrino dynamics in NMSSM with a right-handed sneutrino LSP at the ILC

    Yi Liu🇬🇧 · Stefano Moretti🇬🇧 · Harri Waltari🇬🇧

    We study the possibility of measuring neutrino Yukawa couplings in the Next-to-Minimal Supersymmetric Standard Model with right-handed neutrinos (NMSSMr) when the lightest right-handed sneutrino is the Dark Matter (DM) candidate, by exploiting a `dijet + dilepton + Missing Transverse Energy' signature. We show that, contrary to the miminal realisation of Supersymmetry (SUSY), the MSSM, wherein the DM candidate is typically a much heavier (fermionic) neutralino state, this extended model of SUSY offers one with a much lighter (bosonic) state as DM that can then be produced at the next generation of $e^{+}{e}^{-}$ colliders with energies up to 500 GeV or so. The ensuing signal, energing from chargino pair production and subsequent decay, is extremely pure so it also affords one with the possibility of extracting the Yukawa parameters of the (s)neutrino sector. Altogether, our results serve the purpose of motivating searches for light DM signals at such machines, where the DM candidate can have a mass around the electroweak scale.

    hep-phJHEP(2022)·1 citation
12. 12*

    Reinterpretation of proton strangeness between ATLAS and CMS measurements

    Alim Ruzi🇨🇳 · Bo-Qiang Ma🇨🇳

    We reexamine the shapes of the strange quark parton distribution functions (PDFs) of the proton by means of quantum chromodynamics (QCD) analysis of {\hera} deep inelastic scattering cross section measurement at DESY, and inclusive gauge boson production and $W$ boson production associated with a charm quark from LHC at CERN. We find that there is an overall agreement on the strange quark distributions obtained from CMS $W$ + charm and ATLAS $W/Z$ data at the parton momentum fraction range $x\lesssim 10^{-2}$. Meanwhile, there is also a strong tension between these data towards large $x$. We find that this tension fades away if the ATLAS measurement of $W/Z$ production is analyzed together with the ATLAS $W$ + charm data. The $W/Z$ and $W$ + charm data both from ATLAS and CMS experiments agree that the proton strangeness is enhanced towards small momentum fraction $x$ and is smoothly suppressed at large $x$. Furthermore, a strong $x$ dependence of the strange-to-non-strange parton ratio $R_s(x,Q^2)$ is observed.

    hep-phPRD(2021)·1 citation
13. 13*

    A Tale of Two $U(1)$'s: Kinetic Mixing from Lattice WGC States

    Georges Obied🇺🇸 · Aditya Parikh🇺🇸

    We point out that the states required by the Lattice Weak Gravity Conjecture, along with certain genericity conditions, imply the existence of non-vanishing kinetic mixing between massless Abelian gauge groups in the low-energy effective theory. We carry out a phenomenological estimate using a string-inspired probability distribution for the masses of superextremal states and compare the results to expectations from string theory and field theory, estimating the magnitude of kinetic mixing in each case. In the string case, we compute the kinetic mixing in an ensemble of 1858 MSSM-like heterotic orbifolds as well as in Type II supergravity on a Calabi-Yau manifold. From the field theory perspective, we consider compactifications of a 5D gauge theory. Finally, we discuss potential loopholes that can evade the bounds set by our estimates.

    hep-phhep-th7 citations
14. 14*

    Asymptotic nonlocality in gauge theories

    Jens Boos🇺🇸 · Christopher D. Carone🇺🇸

    Asymptotically nonlocal field theories represent a sequence of higher-derivative theories whose limit point is a ghost-free, infinite-derivative theory. Here we extend this framework, developed previously in a theory of real scalar fields, to gauge theories. We focus primarily on asymptotically nonlocal scalar electrodynamics, first identifying equivalent gauge-invariant formulations of the Lagrangian, one with higher-derivative terms and the other with auxiliary fields instead. We then study mass renormalization of the complex scalar field in each formulation, showing that an emergent nonlocal scale (i.e., one that does not appear as a fundamental parameter in the Lagrangian of the finite-derivative theories) regulates loop integrals as the limiting theory is approached, so that quadratic divergences can be hierarchically smaller than the lightest Lee-Wick partner. We conclude by making preliminary remarks on the generalization of our approach to non-Abelian theories, including an asymptotically nonlocal standard model.

    ↳ hep-thhep-phPRD(2021)·13 citations
15. 15*

    Comparison of $pp$ and $p\bar{p}$ differential elastic cross sections and observation of colourless C-odd gluonic exchanges

    Kenneth Österberg (on behalf of the D0 and TOTEM Collaborations)🇫🇮

    The TOTEM 2.76, 7, 8, and 13 TeV pp elastic differential cross sections are extrapolated using a data-driven approach to obtain the 1.96 TeV pp elastic cross section. A difference with a 3.4$\sigma$ significance is observed between the extrapolated pp elastic cross section and the D0 p$\bar{\mathrm{p}}$ elastic cross section at 1.96 TeV in the region of the diffractive minimum and the second maximum of the pp cross section, providing evidence for colourless C-odd gluonic exchanges, also denoted as odderon. These results are combined with a TOTEM analysis of the same $t$-channel C-odd exchanges based on forward pp elastic scattering at TeV scale. The combined significance is larger than 5$\sigma$ and is interpreted as the first observation of odderon exchange.

    ↳ hep-exhep-ph1 citation
16. 16*

    Fluctuating relativistic dissipative hydrodynamics as a gauge theory

    Travis Dore🇺🇸 · Lorenzo Gavassino🇵🇱 · David Montenegro🇧🇷 · Masoud Shokri🇮🇷 · Giorgio Torrieri🇧🇷

    We argue that different formulations of hydrodynamics are related to uncertainties in the definitions of local thermodynamic and hydrodynamic variables. We show that this ambiguity can be resolved by viewing different formulations of hydrodynamics as particular "gauge choices" which lead to the same physical behavior of the system. Using the example of bulk viscosity, we show that Bemfica-Disconzi-Noronha-Kovtun (BDNK) and Israel-Stewart hydrodynamics are particular "gauge choices" of this type, related by a well-defined transformation of thermodynamic and hydrodynamic variables. We argue that this gauge ambiguity is necessary to ascertain the causality of stochastic hydrodynamic evolution and conjecture that it could explain the applicability of hydrodynamics outside its expected regime of validity since far from equilibrium and close to equilibrium may be related through transformations of this type.

    ↳ hep-thhep-phnucl-thphysics.flu-dynAnnals Phys.(2022)·46 citations
17. 17*

    The Off-Shell Recursion for Gravity and the Classical Double Copy for currents

    Kyoungho Cho🇰🇷 · Kwangeon Kim🇰🇷 · Kanghoon Lee🇰🇷

    We construct the off-shell recursion for gravity and the graviton current for the perturbative double field theory (DFT). We first formulate the perturbative DFT, which is equivalent but simpler to perturbative general relativity, to all-orders in fluctuations of generalised metric. The perturbative action and equations of motion (EoM) are derived to arbitrary order for pure gravity case. We then derive the graviton off-shell recursion, the gravity counterpart of the Berends-Giele recursion in Yang-Mills theory, through the so-called perturbiner method using the EoM of the perturbative DFT. We solve the recursion iteratively and obtain the graviton off-shell currents explicitly. We then discuss the classical double copy for the off-shell currents. We present the current KLT relation for gravity by extending the result proposed by Mizera and Skrzypek for the non-gravitational effective field theories. The relation represents graviton currents by squaring gluon currents with the KLT kernel up to gauge transformation and regular terms that do not have any pole. Finally we discuss the off-shell conservation of currents for nonlinear gauge choices.

    ↳ hep-thgr-qchep-phJHEP(2022)·47 citations
18. 18*

    Gravitational wave trispectrum in the axion-SU(2) model

    Tomohiro Fujita🇯🇵 · Kai Murai🇯🇵 · Ippei Obata🇩🇪 · Maresuke Shiraishi🇯🇵

    We study the trispectrum of the gravitational waves (GWs) generated through the dynamics of an axionic spectator field and SU(2) gauge fields during inflation. In non-Abelian gauge theory, the gauge fields have four-point self-interactions, which induce the tree-level GW trispectrum. We formulate this type of the GW trispectrum including the non-dynamical contributions and evaluate it in the equilateral limit as a unique signal of this model. We find that the ratio of the GW trispectrum to the cube of the scalar power spectrum can be as large as $\mathcal{O}(10^6)$ in the viable parameter space, which could be captured in the CMB observations.

    ↳ astro-ph.COhep-phJCAP(2022)·22 citations
19. 19*

    Hydrodynamic attractor in the non-conformal Bjorken flow

    Zenan Chen🇨🇳 · Li Yan🇨🇳

    Non-conformal attractor behavior is studied by solving non-conformal second order viscous hydrodynamics with respect to boost-invariant plasmas. Numerical solutions of the relative decay rate of the enthalpy density, the inverse shear and bulk Reynolds numbers, all exhibit universal patterns towards an ideal fluid description at late stages, demonstrating the existence of non-conformal hydrodynamic attractor. However, as a generic feature, the non-conformal hydrodynamic attractor emerges only at late times, which differs drastically from the behavior observed in conformal systems. The absence of the early-time attractor in non-conformal fluids is a consequence of the early-time instable mode, which arises from a positive-valued eigen-mode associated with the free-streaming dynamics. To support practical simulations of hydrodynamics in high-energy heavy-ion collisions, early-time attractor can be restored in a mixture of the shear and the bulk viscous corrections, in which early-time instable modes cancel approximately. Early-time non-conformal attractor is also approachable, if the quadratic coupling between the bulk pressure and the expansion rate is enhanced by at least a factor of two through the transport coefficient ${\delta }_{\Pi \Pi }$.

    ↳ nucl-thhep-phPRC(2022)·11 citations
20. 20*

    Equation of state of neutron star matter and its warm extension with an interacting hadron resonance gas

    Yuki Fujimoto🇯🇵 · Kenji Fukushima🇯🇵 · Yoshimasa Hidaka🇯🇵 · Atsuki Hiraguchi🇹🇼 · Kei Iida🇯🇵

    We propose an interpolating equation of state that satisfies phenomenologically established boundary conditions in two extreme regimes at high temperature and low baryon density and at low temperature and high baryon density. We confirm that the hadron resonance gas model with the Carnahan-Starling excluded volume effect can reasonably fit the empirical equation of state at high density up to several times the normal nuclear density. We identify the onsets of strange particles and quantify the strangeness contents in dense matter. We finally discuss the finite temperature effects and estimate the thermal index ${\Gamma }_{\mathrm{th}}$ as a function of the baryon density, which should be a crucial input for the core-collapse supernova and the binary neutron star merger simulations.

    ↳ nucl-thastro-ph.HEhep-phPLB(2022)·18 citations
21. 21*

    On Warped String Vacuum Profiles and Cosmologies, I. Supersymmetric Strngs

    J. Mourad🇫🇷 · A. Sagnotti🇮🇹

    We investigate in detail solutions of supergravity that involve warped products of flat geometries of the type M(p+1) x R x T(D-p-2) depending on a single coordinate. In the absence of fluxes, the solutions include flat space and Kasner-like vacua that break all supersymmetries. In the presence of a symmetric flux, there are three families of solutions that are characterized by a pair of boundaries and have a singularity at one of them, the origin. The first family comprises supersymmetric vacua, which capture a universal limiting behavior at the origin. The first and second families also contain non--supersymmetric solutions whose behavior at the other boundary, which can lie at a finite or infinite distance, is captured by the no--flux solutions. The solutions of the third family have a second boundary at a finite distance where they approach again the supersymmetric backgrounds. These vacua exhibit a variety of interesting scenarios, which include compactifications on finite intervals and (p+1)-dimensional effective theories where the string coupling has an upper bound. We also build corresponding cosmologies, and in some of them the string coupling can be finite throughout the evolution.

    ↳ hep-thastro-ph.COgr-qchep-phJHEP(2021)·25 citations
22. 22*

    Diagrammar of physical and fake particles and spectral optical theorem

    Damiano Anselmi🇮🇹

    We prove spectral optical identities in quantum field theories of physical particles (defined by the Feynman $iϵ$ prescription) and purely virtual particles (defined by the fakeon prescription). The identities are derived by means of purely algebraic operations and hold for every (multi)threshold separately and for arbitrary frequencies. Their major significance is that they offer a deeper understanding on the problem of unitarity in quantum field theory. In particular, they apply to "skeleton" diagrams, before integrating on the space components of the loop momenta and the phase spaces. In turn, the skeleton diagrams obey a spectral optical theorem, which gives the usual optical theorem for amplitudes, once the integrals on the space components of the loop momenta and the phase spaces are restored. The fakeon prescription/projection is implemented by dropping the thresholds that involve fakeon frequencies. We give examples at one loop (bubble, triangle, box, pentagon and hexagon), two loops (triangle with "diagonal", box with diagonal) and arbitrarily many loops. We also derive formulas for the loop integrals with fakeons and relate them to the known formulas for the loop integrals with physical particles.

    ↳ hep-thhep-exhep-phJHEP(2021)·45 citations
23. 23*

    Application of Deep Learning Technique to an Analysis of Hard Scattering Processes at Colliders

    Lev Dudko🇷🇺 · Petr Volkov🇷🇺 · Georgii Vorotnikov🇷🇺 · Andrei Zaborenko🇷🇺

    Deep neural networks have rightfully won the place of one of the most accurate analysis tools in high energy physics. In this paper we will cover several methods of improving the performance of a deep neural network in a classification task in an instance of top quark analysis. The approaches and recommendations will cover hyperparameter tuning, boosting on errors and AutoML algorithms applied to collider physics.

    ↳ physics.data-anhep-exhep-phPoS(2022)·0 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.