Fri·Apr 17, 2020Friday·April 17, 2020

1. 01*

   Scaling of high-energy elastic scattering and the observation of Odderon

   T. Csörgő🇭🇺 · T. Novák🇭🇺 · R. Pasechnik🇸🇪 · A. Ster🇭🇺 · I. Szanyi🇭🇺

   We provide a statistically significant observation of the elusive Odderon exchange, based on novel and model-independent analysis of the scaling properties of the differential cross sections of elastic $pp$ and $p\bar{p}$ scattering in the TeV energy range. We report the statistical significance of the observed Odderon signal at the level of 6.26$\sigma$.

   hep-phhep-exnucl-exGribov-90 Memorial Volume, pp. 69-80 (202…·4 citations
2. 02*

   Effects of in-medium $k_T$ broadening on di-jet observables

   Martin Rohrmoser🇵🇱

   We study the influence of in-medium transverse momentum broadening on observables of jet pairs produced in nuclear collisions. These dijets were obtained numerically via the Monte-Carlo simulations of nuclear collisions, where the partons within the colliding nuclei were described via unintegrated parton densities, and their subsequent propagation within the medium of a quark-gluon plasma (QGP). For jet-evolution in the QGP both, kicks transverse to the momentum of the incoming particle as well as medium induced radiation were considered. After favorable comparison of our results with experimental LHC-data on jet-quenching we make predictions for the decorrelation of dijets. In particular, we study deviations from a transverse momentum broadening that follows a Gaussian distribution.

   hep-phActa Phys.Polon.B(2020)·0 citations
3. 03*

   Roper-like resonances with various flavor contents and their two-pion emission decays

   A. J. Arifi🇯🇵 · H. Nagahiro🇯🇵 · A. Hosaka🇯🇵 · K. Tanida🇯🇵

   We study the three-body decay of the newly observed bottom baryon ${\Lambda }_b^{\ast }(6072)$ by LHCb; ${\Lambda }_b^{\ast }(6072)\to {\Lambda }_b\pi \pi$. Its mass about 500 MeV above the ground state ${\Lambda }_b$ and a broad width imply that the state could be an analogue of the Roper resonance of the nucleon $N(1440)$. In terms of sequential processes going through ${\Sigma }_b$ and ${\Sigma }_b^{\ast }$, we find that the observed invariant mass distribution is reproduced assuming its spin and parity $J^P=1/2^{+}$. We discuss that the ratio of the two sequential processes and angular correlation of two pions are useful for the determination of spin and parity. We suggest further studies for the Roper resonance analogue in various flavor contents, raising an interesting and important question in baryon spectroscopy.

   hep-phnucl-thPRD(2020)·21 citations
4. 04*

   Triply charmed dibaryons in the one boson exchange model

   Ya-Wen Pan🇨🇳 · Ming-Zhu Liu🇨🇳 · Li-Sheng Geng🇨🇳

   The pentaquark states, $P_c(4312)$, $P_c(4440)$ and $P_c(4450)$, can be nicely arranged into a multiplet of seven molecules of ${\bar{D}}^{(\ast )}{\Sigma }_c^{(\ast )}$ dictated by heavy quark spin symmetry, while the ${\Xi }_{cc}^{(\ast )}{\Sigma }_c^{(\ast )}$ system can be related to the ${\bar{D}}^{(\ast )}{\Sigma }_c^{(\ast )}$ system via heavy antiquark diquark symmetry. In this work we employ the one boson exchange model to study the interactions between ${\Xi }_{cc}^{(\ast )}$ and ${\Sigma }_c^{(\ast )}$ with constraints from the pentaquark system. We show that a multiplet of ten triply charmed dibaryons emerge naturally in the isospin-1/2 sector, while only three appear in the isospin-3/2 sector. In addition, we study their heavy quark flavor partners. Ten triply bottom diybaryons are found in the isospin-1/2 sector, while only nine are likely in the isospin-3/2 sector. Furthermore, the predicted mass splitting between the $0^{+}$ ${\Xi }_{cc}{\Sigma }_c$ state and its $1^{+}$ counterpart is found to be consistent with the correlation implied by heavy antiquark diquark symmetry recently pointed out in Pan $et$ $al$..

   hep-phhep-latPRD(2020)·20 citations
5. 05*

   The chiral magnetic effect and the chiral spin symmetry in QCD above Tc

   L. Ya. Glozman🇦🇹

   The chiral magnetic effect (CME) is an exact statement that connects via the axial anomaly the electric current in a system consisting of interacting fermions and gauge field with chirality imbalance that is put into a strong external magnetic field. Experimental search of the magnetically induced current in QCD in heavy ion collisions above a pseudocritical temperature hints, though not yet conclusive, that the induced current is either small or vanishing. This would imply that the chirality imbalance in QCD above $T_c$ that could be generated via topological fluctuations is at most very small. Here we present the most general reason for absence (smallness) of the chirality imbalance in QCD above Tc. It was recently found on the lattice that QCD above Tc is approximately chiral spin (CS) symmetric with the symmetry breaking at the level of a few percent. The CS transformations mix the right- and left-handed components of quarks. Then an exact CS symmetry would require absence of any chirality imbalance. Consequently an approximate CS symmetry admits at most a very small chirality imbalance in QCD above Tc. Hence the absence or smallness of an magnetically induced current observed in heavy ion collisions could be considered as experimental evidence for emergence of the CS symmetry above Tc.

   hep-phhep-lathep-thnucl-th1 citation
6. 06*

   Trijets in kt-factorisation: matrix elements vs parton shower

   H. Van Haevermaet🇧🇪 · A. Van Hameren🇵🇱 · P. Kotko🇵🇱 · K. Kutak🇵🇱 · P. Van Mechelen🇧🇪

   We study 3-jet event topologies in proton-proton collisions at a centre-of-mass energy of $\sqrt{s}=13\mathrm{TeV}$ in a configuration, where one jet is present in the central pseudorapidity region ($|\eta |<2.0$) while two other jets are in a more forward (same hemisphere) area ($|\eta |>2.0$). We compare various parton level predictions using: collinear factorisation, $\text{KT}$-factorisation with fully off-shell matrix elements and the hybrid framework. We study the influence of different parton distribution functions, initial state radiation, final state radiation, and hadronisation. We focus on differential cross sections as a function of azimuthal angle difference between the leading dijet system and the third jet, which is found to have excellent sensitivity to the physical effects under study.

   hep-phEPJC(2020)·16 citations
7. 07*

   Nonintegrable threshold singularities of two-point functions in perturbation theory

   Dmitri Melikhov🇷🇺 · Silvano Simula🇮🇹

   In perturbation theory, the spectral densities of two-point functions develop non-integrable threshold singularities at higher orders. In QCD, such singularities emerge when calculating the diagrams in terms of the pole quark mass, and they become stronger when one rearranges the perturbative expansion in terms of the running quark mass. In this paper we discuss the proper way to handle such singularities.

   hep-phEur.Phys.J.Plus(2021)·0 citations
8. 08*

   Statistical Significance of Reactor Antineutrino Active-Sterile Oscillations

   C. Giunti🇮🇹

   We performed Monte Carlo calculations of the statistical distribution of the ${\chi }^2$ test statistic used in the analysis of the data of the NEOS, DANSS, Bugey-3, and PROSPECT short-baseline reactor experiments. We show that the statistical significance of the NEOS and DANSS indications in favor of active-sterile neutrino oscillations is smaller than that obtained with the usual method based on the ${\chi }^2$ distribution. In the combined analysis of the data of the four experiments we find that the statistical significance of active-sterile neutrino oscillations is reduced from $2.4\sigma$ to $1.8\sigma$.

   hep-phhep-exPRD(2020)·27 citations
9. 09*

   Signs of new physics in top quark pair production associated with a neutrino pair at the LHC

   Daruosh Haji Raissi🇮🇷 · Javad Ebadi🇮🇷 · Mojtaba Mohammadi Najafabadi🇮🇷

   In this paper, we examine the interactions of the top quarks with the $Z$ boson using the top quark pair production associated with neutrino pair ($t\bar{t}{\nu }_l\overline{{\nu }_l}$) at the LHC. In particular, potential constraints on the anomalous electroweak top-quark interactions are determined by considering two opposite-sign charged leptons, missing energy, and two b-tagged jets in the final state. The analysis is performed for a High Luminosity scenario of the LHC with an integrated luminosity of 3 ab${}^{-1}$ of proton-proton collisions at a center-of-mass energy of 14 TeV. The $95\%$ confidence intervals are computed on the anomalous couplings considering a realistic detector simulation of an upgraded CMS detector including an average of 200 proton-proton interactions per bunch crossing. We find that the $t\bar{t}{\nu }_l\overline{{\nu }_l}$ channel can provide stringent bounds on the relevant Wilson coefficients and has the potential to serve as an additional handle beside the $t\bar{t}Z(Z\to l^{+}{l}^{-})$ and other channels to search for new physics.

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

    Inelasticity resulting from rapidity spectra analysis

    Zbigniew Włodarczyk🇵🇱 · Maciej Rybczyński🇵🇱

    In this work we study the pseudorapidity spectra o charged particles produced in proton+proton and proton+antiproton interactions in a wide energy range using the non-extensive Tsallis approach. We evaluate the inelasticity coefficients of the discussed reactions which remain approximately independent of the collision energy.

    hep-phnucl-thNew J.Phys.(2020)·1 citation
11. 11*

    Lepton number violation in a unified framework

    Yuta Kawamura🇯🇵 · Yamato Matsuo🇯🇵 · Takuya Morozumi🇯🇵 · Apriadi Salim Adam🇯🇵 · Yusuke Shimizu🇯🇵 · Yuya Tokunaga🇯🇵 · Naoya Toyota🇯🇵

    We study the time evolution of lepton family number for neutrino which forms SU(2) doublet with charged lepton. The lepton family number is defined through a weak basis of SU(2) doublet in which the charged lepton mass matrix is a real and diagonal one. The lepton family number carried by the neutrino is defined with a left-handed current of the neutrino family. We study the time evolution of the lepton family number operator for Majorana neutrino. To be definite, we introduce the mass term at $t=0$ and study the time evolution of the lepton family number for the later time. Since the operator in flavor eigenstate is continuously connected to that of the mass eigenstate, the creation and annihilation operators for flavor eigenstates are related to those of mass eigenstates. The total lepton number of the Majorana neutrino is conserved. By choosing a specific flavor eigenstate of neutrino as an initial state, we compute the time evolution of all lepton family numbers. They are sensitive to Majorana and Dirac phases and also are sensitive to the absolute mass and mass hierarchy of neutrinos.

    hep-phPTEP(2020)·1 citation
12. 12*

    Asymmetric dark matter from semi-annihilation

    Avirup Ghosh🇮🇳 · Deep Ghosh🇮🇳 · Satyanarayan Mukhopadhyay🇮🇳

    We show that a general semi-annihilation scenario, in which a pair of dark matter (DM) particles annihilate to an anti-DM, and an unstable state that can mix with or decay to standard model states, can lead to particle anti-particle asymmetry in the DM sector. The present DM abundance, including the CP-violation in the DM sector and the resulting present asymmetry are determined entirely by a single semi-annihilation process at next-to-leading order. For large CP-violation in this process, we find that a nearly complete asymmetry can be obtained in the DM sector, with the observed DM density being dominated by the (anti-)DM particle. The presence of additional pair-annihilation processes can modify the ratio of DM and anti-DM number densities further, if the pair-annihilation is active subsequent to the decoupling of the semi-annihilation. For such a scenario, the required CP-violation for generating the same present asymmetry is generically much smaller, as compared to the scenario with only semi-annihilation present. We show that a minimal model with a complex scalar DM with cubic self-interactions can give rise to both semi- and pair-annihilations, with the required CP-violation generated at one-loop level. We also find that the upper bound on the DM mass from S-matrix unitarity in the purely asymmetric semi-annihilation scenario, with maximal CP-violation, is around 15 GeV, which is much stronger than in the WIMP and previously considered asymmetric DM cases, due to the required large non-zero chemical potential for such asymmetric DM.

    hep-phJHEP(2020)·29 citations
13. 13*

    Accurate single- and double-differential resummation of colour-singlet processes with MATRIX+RadISH: $W^{+}{W}^{-}$ production at the LHC

    Stefan Kallweit🇮🇹 · Emanuele Re🇫🇷 · Luca Rottoli🇮🇹 · Marius Wiesemann🇩🇪

    We present the combination of fully differential cross sections for colour-singlet production processes at next-to-next-to-leading order (NNLO) QCD obtained with MATRIX and all-order resummation through RadISH. This interface allows us to achieve unprecedented accuracy for various transverse observables in $2\to 2$ production processes. As an important application we consider $W^{+}{W}^{-}$ production at the LHC, more precisely the full leptonic process $pp\to {\ell }^{+}{\ell }^{\prime -}{\nu }_{\ell }{\bar{\nu }}_{{\ell }^{\prime }}+X$ with ${\ell }^{\prime }\ne \ell$, and we present resummed predictions for differential distributions in presence of fiducial selection cuts. In particular, we resum the transverse-momentum spectrum of the $W^{+}{W}^{-}$ pair at next-to-next-to-next-to-leading logarithmic (N${}^3$LL) accuracy and match it to the integrated NNLO cross section. The transverse-momentum spectrum of the leading jet in $W^{+}{W}^{-}$ production is calculated at NNLO+NNLL accuracy. Finally, the joint resummation for the transverse-momentum spectrum of the $W^{+}{W}^{-}$ pair in the presence of a jet veto is performed at NNLO+NNLL. Our phenomenological study highlights the importance of higher-order perturbative and logarithmic corrections for precision phenomenology at the LHC.

    hep-phJHEP(2020)·66 citations
14. 14*

    Light-Front Holography and Supersymmetric Conformal Algebra: A Novel Approach to Hadron Spectroscopy, Structure, and Dynamics

    Stanley J. Brodsky🇺🇸 · Guy F. de Teramond🇨🇷 · Hans Gunter Dosch🇩🇪

    We give an overview of recent progress into the infrared structure of QCD based on the gauge/gravity correspondence and light-front quantization, where the color confining interaction for mesons and baryons is determined by an underlying superconformal algebraic structure. This new approach to hadron physics gives remarkable connections and predictions across the entire mass spectrum of hadrons and also describes the infrared behavior of the strong coupling. More recently, an extensive study of form factors, polarized and unpolarized parton distributions and the sea quark contribution to the nucleon has been carried out by extending the holographic formalism to incorporate the nonperturbative structure of Veneziano amplitudes. Contribution to the report "Strong QCD from Hadron Structure Experiments" Jefferson Lab Workshop, 5-9 November, 2019

    hep-phhep-th19 citations
15. 15*

    QZE and IZE in a simple approach and the neutron decay

    Francesco Giacosa🇵🇱

    We discuss a simple and analytically solvable measurement model which describes the famous Quantum Zeno Effect (QZE) and Inverse Zeno Effect (IZE), that correspond to the slow down and to the increase of the decay rate caused by measurements (or, more in general, by the interaction of an unstable state with the detector and the environment). Within this model one can understand quite general features of the QZE and IZE: by considering an unstable quantum state, such as an unstable particle, whose decay width as function of energy is $\Gamma (\omega )=g^2{\omega }^{\alpha },$ then -- under quite general assumptions -- the QZE occurs for $\alpha \in (0,1)$, while the IZE for $\alpha \in (-\infty ,0)\cup (1,\infty ).$ This result is valid also for more realistic measurement models than the one described in this work. We then apply these considerations to the decay of the neutron, for which $\alpha =5.$ Hence, the realization of the IZE for the neutron decay (and for the majority of weak decays) is in principle possible. Indeed, trap experiments find a lifetime that is $8.7\pm 2.1$ s shorter than beam experiments, suggesting that the IZE could have taken place.

    hep-phnucl-thquant-phActa Phys.Polon.B(2020)·1 citation
16. 16*

    Neutrino Masses and Noncyclic Geometric Phase of Entangled Charged Lepton-Neutrino Pair in External Magnetic Field

    Jianlong Lu🇸🇬

    In this paper, we consider a pair of entangled charged lepton-neutrino embedded in a constant magnetic field, which can be produced in the purely leptonic decay of charged pseudoscalar mesons. Particles with nonzero magnetic dipole moment will precess in the present of external magnetic field and induce a nontrivial noncyclic geometric phase. The dependence of this geometric phase on neutrino mass can be used to determine the Dirac/Majorana nature of massive neutrinos.

    hep-ph0 citations
17. 17*

    Gravitational waves from the fragmentation of axion-like particle dark matter

    Aleksandr Chatrchyan🇩🇪 · Joerg Jaeckel🇩🇪

    The misalignment mechanism allows for the efficient, and usually very cold, production of light scalar bosons, such as axion-like particles (ALPs), making them an appealing dark matter candidate. However, in certain cases, such as in the presence of a monodromy, the self-interactions of ALPs can be sufficiently strong such that the homogeneous field fragments soon after the onset of oscillations. The resulting large inhomogeneities can lead to the production of gravitational waves (GWs). We investigate the nonlinear dynamics of fragmentation, as well as of the subsequent turbulent regime, and calculate the stochastic GW background that is produced from this process. The GW background can be enhanced if the time evolution features an extended intermediate phase of ultrarelativistic dynamics due to a small mass at the bottom of the potential. Yet, this enhancement is limited by the requirement that the dark matter remains sufficiently cold. In some cases the resulting GWs may be within reach of future GW detectors, allowing a complementary probe of this type of dark matter.

    hep-phastro-ph.COJCAP(2021)·42 citations
18. 18*

    Constraining New Physics with Single Top production at LHC

    Daniel Stolarski🇨🇦 · Alberto Tonero🇨🇦

    We study effects of beyond the Standard Model physics coupling third generation quarks to leptons of the first two generations. We parametrize these effects by dimension-six effective operators, and we also consider related simplified UV completions: scalar leptoquark and $W^{\prime }$ models. We derive new constraints on these scenarios by using recent ATLAS measurements of differential cross sections of single top production in association with a $W$ boson, and also show how these limits will evolve with future data. We also describe how the limits can be significantly improved by using ratios of differential distributions with different flavors of leptons.

    hep-phJHEP(2020)·8 citations
19. 19*

    Doubly-Charged Bileptons at the LHC

    Paul H. Frampton🇮🇹

    We discuss a minimal and simple extension of the standard electroweak model and discuss its uniqueness properties. Its most readily testable prediction is the existence of $|Q|=|L|=2$ gauge bosons, bileptons, which decay into like-sign lepton pairs. We discuss how a discovery could be made at the LHC.

    hep-ph0 citations
20. 20*

    ${}^{12}$C(e,e'pN) Measurements of Short Range Correlations in the Tensor-to-Scalar Interaction Transition Region

    I. Korover · J. R. Pybus · A. Schmidt · F. Hauenstein · M. Duer · O. Hen · E. Piasetzky · L.B. Weinstein · D.W. Higinbotham · the CLAS Collaboration

    High-momentum configurations of nucleon pairs at short-distance are probed using measurements of the ${}^{12}$C$(e,e^{\prime }p)$ and ${}^{12}$C$(e,e^{\prime }pN)$ reactions (where $N$ is either $n$ or $p$), at high-$Q^2$ and $x_B>1.1$. The data span a missing-momentum range of 300--1000 MeV/c and are predominantly sensitive to the transition region of the strong nuclear interaction from a Tensor to Scalar interaction. The data are well reproduced by theoretical calculations using the Generalized Contact Formalism with both chiral and phenomenological nucleon-nucleon ($NN$) interaction models. This agreement suggests that the measured high missing-momentum protons up to $1000$ MeV/c predominantly belong to short-ranged correlated (SRC) pairs. The measured ${}^{12}$C$(e,e^{\prime }pN)$ / ${}^{12}$C$(e,e^{\prime }p)$ and ${}^{12}$C$(e,e^{\prime }pp)$ / ${}^{12}$C$(e,e^{\prime }pn)$ cross-section ratios are consistent with a decrease in the fraction of proton-neutron SRC pairs and increase in the fraction of proton-proton SRC pairs with increasing missing momentum. This confirms the transition from an isospin-dependent tensor $NN$ interaction at $\sim 400$ MeV/c to an isospin-independent scalar interaction at high-momentum around $\sim 800$ MeV/c as predicted by theoretical calculation.

    ↳ nucl-exhep-phnucl-thPLB(2021)·48 citations
21. 21*

    Neutrinoless Double Beta Decay from Lattice QCD: The Long-Distance ${\pi }^{-}\to {\pi }^{+}{e}^{-}{e}^{-}$ Amplitude

    W. Detmold🇺🇸 · D.J. Murphy🇺🇸

    Neutrinoless double beta decay (\( 0 \nu \beta \beta \)) is a hypothetical nuclear decay mode with important implications. In particular, observation of this decay would demonstrate that the neutrino is a Majorana particle and that lepton number conservation is violated in nature. Relating experimental constraints on \(0 \nu \beta \beta\) decay rates to the neutrino masses requires theoretical input in the form of non-perturbative nuclear matrix elements which remain difficult to calculate reliably. This work marks a first step toward providing a general lattice QCD framework for computing long-distance \(0 \nu \beta \beta\) matrix elements in the case where the decay is mediated by a light Majorana neutrino. The relevant formalism is developed and then tested by computing the simplest such matrix element describing an unphysical \( \pi^{-} \rightarrow \pi^{+} e^{-} e^{-} \) transition on a series of domain wall fermion ensembles. The resulting lattice data is then fit to next-to-leading-order chiral perturbation theory, allowing a fully-controlled extraction of the low energy constant governing the transition rate, \(g_{\nu}^{\pi \pi}(\mu = 770 \,\, \mathrm{MeV}) = -10.78(12)_{\rm stat}(51)_{\rm sys}\). Finally, future prospects for calculations of more complicated processes, such as the phenomenologically important \(n^{0} n^{0} \rightarrow p^{+} p^{+} e^{-} e^{-}\) decay, are discussed.

    ↳ hep-lathep-phnucl-th40 citations
22. 22*

    Semiclassical transport equations of Dirac particles in rotating frames

    O.F.Dayi🇹🇷 · E. Kilincarslan🇹🇷

    We establish covariant semiclassical transport equations of massive spin-1/2 particles which are generated by the quantum kinetic equation modified by enthalpy current dependent terms. The purpose of modification is to take into account the noninertial properties due to the angular velocity of rotating frame which is equivalent to the fluid vorticity in hydrodynamical approach. We present the equations satisfied by the Wigner function components and by studying their solution in the semiclassical approximation we accomplish the transport equations. To acquire a three-dimensional kinetic theory, the relativistic kinetic equations in the comoving frame are integrated over the zeroth component of four-momentum. The resulting vector and axial-vector currents are calculated at zero temperature. There exists another three-dimensional formulation of Dirac particles which correctly addresses the noninertial features of rotating coordinates. We review it briefly and obtain the mass corrections to the chiral vector and axial-vector currents produced by this formulation.

    ↳ hep-thhep-phPRD(2020)·11 citations
23. 23*

    Momentum-kick model application to high multiplicity pp collisions at $\sqrt{s}=13\mathrm{TeV}$ at the LHC

    Beomkyu Kim🇰🇷 · Hanul Youn🇰🇷 · Soyeon Cho🇰🇷 · Jin-Hee Yoon🇰🇷

    In this study, the momentum-kick model is used to understand the ridge behaviours in dihadron $\Delta \eta$--$\Delta \phi$ correlations recently reported by the LHC in high-multiplicity proton-proton (pp) collisions. The kick stand model is based on a momentum kick by leading jets to partons in the medium close to the leading jets. The medium where partons move freely is assumed in the model regardless of collision systems. This helps us apply the method to small systems like pp collisions in a simple way. Also, the momentum transfer is purely kinematic and this provides us a strong way to approach the ridge behaviour analytically. There are already several results with this approach in high-energy heavy-ion collisions from the STAR and PHENIX at RHIC and from the CMS at LHC. The momentum-kick model is extended to the recent ridge results in high-multiplicity pp collisions with the ATLAS and CMS at LHC. The medium property in high-multiplicity pp collisions is diagnosed with the result of the model.

    ↳ nucl-thhep-phInt.J.Theor.Phys.(2021)·3 citations
24. 24*

    Convergence of Eigenvector Continuation

    Avik Sarkar🇺🇸 · Dean Lee🇺🇸

    Eigenvector continuation is a computational method that finds the extremal eigenvalues and eigenvectors of a Hamiltonian matrix with one or more control parameters. It does this by projection onto a subspace of eigenvectors corresponding to selected training values of the control parameters. The method has proven to be very efficient and accurate for interpolating and extrapolating eigenvectors. However, almost nothing is known about how the method converges, and its rapid convergence properties have remained mysterious. In this letter we present the first study of the convergence of eigenvector continuation. In order to perform the mathematical analysis, we introduce a new variant of eigenvector continuation that we call vector continuation. We first prove that eigenvector continuation and vector continuation have identical convergence properties and then analyze the convergence of vector continuation. Our analysis shows that, in general, eigenvector continuation converges more rapidly than perturbation theory. The faster convergence is achieved by eliminating a phenomenon that we call differential folding, the interference between non-orthogonal vectors appearing at different orders in perturbation theory. From our analysis we can predict how eigenvector continuation converges both inside and outside the radius of convergence of perturbation theory. While eigenvector continuation is a non-perturbative method, we show that its rate of convergence can be deduced from power series expansions of the eigenvectors. Our results also yield new insights into the nature of divergences in perturbation theory.

    ↳ nucl-thcond-mat.str-elcs.NAhep-lat+2PRL(2021)·58 citations
25. 25*

    Lifshitz-scaling in CPT-even Lorentz-violating electrodynamics and GRB time delay

    K. E. L. de Farias🇧🇷 · T. A. M. Sampaio🇧🇷 · M. A. Anacleto🇧🇷 · F. A. Brito🇧🇷 · E. Passos🇧🇷

    In this work, we consider the Hořava-Lifshitz scaling to rewrite higher-order derivatives in Lorentz-violating CPT-even electrodynamics. The possibility of the Lorentz invariance violation being originally suppressed by the quantum gravity energy scale $M_{\mathrm{QG}}$, may be indeed circumvented in a scenario with anisotropy between space and time above certain intermediate energy scale ${\Lambda }_{\mathrm{HL}}\ll M_{\mathrm{QG}}$. To test the model, we have used observational results of a cosmological time delay between high and low energy photons from gamma ray bursts (GRB090510) event. For specific values of the Lifshitz critical exponent, we have found interesting lower bounds on the values of $M_{\mathrm{QG}}$.

    ↳ hep-thhep-phEur.Phys.J.Plus(2021)·7 citations
26. 26*

    Late-time decaying dark matter: constraints and implications for the $H_0$-tension

    Balakrishna S. Haridasu🇮🇹 · Matteo Viel🇮🇹

    We constrain and update the bounds on the life-time of a decaying dark matter model with a warm massive daughter particle using the most recent low-redshift probes. We use Supernovae Type-Ia, Baryon Acoustic Oscillations and the time delay measurements of gravitationally lensed quasars. These data sets are complemented by the early universe priors taken from the Cosmic Microwave background. For the maximum allowed fraction of the relativistic daughter particle, the updated bounds on the life-time are found to be $\tau >9\mathrm{Gyr}$ and $\tau >11\mathrm{Gyr}$ at $95\%$ C.L., for the two-body and many-body decay scenarios, respectively. We also comment on the recent proposal that the current two-body decaying dark matter model can provide resolution for the $H_0$-tension, by contrasting against the standard $\Lambda$CDM model. We infer that the current dark matter decaying scenario is unlikely to alleviate the $H_0$-tension. We find that the decaying dark matter is able to reduce the trend of the decreasing $H_0$ values with increasing lens redshifts observed in the strong lensing dataset.

    ↳ astro-ph.COhep-phMNRAS(2020)·58 citations
27. 27*

    Quantifying uncertainties and correlations in the nuclear-matter equation of state

    C. Drischler🇺🇸 · J. A. Melendez🇺🇸 · R. J. Furnstahl🇺🇸 · D. R. Phillips🇺🇸

    We perform statistically rigorous uncertainty quantification (UQ) for chiral effective field theory ($\chi$EFT) applied to infinite nuclear matter up to twice nuclear saturation density. The equation of state (EOS) is based on high-order many-body perturbation theory calculations with nucleon-nucleon and three-nucleon interactions up to fourth order in the $\chi$EFT expansion. From these calculations our newly developed Bayesian machine-learning approach extracts the size and smoothness properties of the correlated EFT truncation error. We then propose a novel extension that uses multitask machine learning to reveal correlations between the EOS at different proton fractions. The inferred in-medium $\chi$EFT breakdown scale in pure neutron matter and symmetric nuclear matter is consistent with that from free-space nucleon-nucleon scattering. These significant advances allow us to provide posterior distributions for the nuclear saturation point and propagate theoretical uncertainties to derived quantities: the pressure and incompressibility of symmetric nuclear matter, the nuclear symmetry energy, and its derivative. Our results, which are validated by statistical diagnostics, demonstrate that an understanding of truncation-error correlations between different densities and different observables is crucial for reliable UQ. The methods developed here are publicly available as annotated Jupyter notebooks.

    ↳ nucl-thastro-ph.HEhep-phnucl-exPRC(2020)·165 citations
28. 28*

    Further studies on the physics potential of an experiment using LHC neutrinos

    N. Beni (1 and 2) · M. Brucoli (2) · V. Cafaro (3) · F. Cerutti (2) · G. M. Dallavalle (3) · S. Danzeca (2) · A. DeRoeck (2) · A. De Rujula (4) · D. Fasanella (2) · V. Giordano (3) · C. Guandalini (3) · A. Ioannisyan (2 and 5) and 12 other authors

    We discuss an experiment to investigate neutrino physics at the LHC in Run 3, with emphasis on tau flavour. As described in our previous paper [arXiv:1903.06564v1], the detector can be installed in the decommissioned TI18 tunnel, about 480 m downstream the ATLAS cavern, after the first bending dipoles of the LHC arc. In that location, the prolongation of the beam Line-of-Sight from Interaction Point IP1 to TI18 traverses about 100 m of rock. The detector intercepts the intense neutrino flux, generated by the LHC beams colliding in IP1, at large pseudorapidity eta, where neutrino energies can exceed a TeV. This paper focuses on optimizing global features of the experiment, like detector mass and acceptance. Since the neutrino-nucleon interaction cross section grows almost linearly with energy, the detector can be light and still collect a considerable sample of neutrino events; in the present study it weighs less than 3 tons. The detector is positioned off the beam axis, slightly above the ideal prolongation of the LHC beam from the straight section, covering 7.4 < eta < 9.2. In this configuration, the flux at high energies (0.5-1.5 TeV and beyond) is found to be dominated by neutrinos originating directly from IP1, mostly from charm decays, of which about 50% are electron neutrinos and about 5% are tau neutrinos. The contribution of pion and kaon decays to the muon neutrino flux is studied by means of simulations that embed the LHC optics and found small at high energies. The above studies indicate that with 150 /fb of delivered LHC luminosity in Run 3 the experiment can record a few thousand very high energy neutrino charged current interactions and over 50 tau neutrino charged current events.

    ↳ hep-exhep-phphysics.ins-detJ.Phys.G(2020)·26 citations
29. 29*

    Towards a unitary, renormalizable and ultraviolet-complete quantum theory of gravity

    Christian F. Steinwachs🇩🇪

    For any fundamental quantum field theory, unitarity, renormalizability, and relativistic invariance are considered to be essential properties. Unitarity is inevitably connected to the probabilistic interpretation of the quantum theory, while renormalizability guarantees its completeness. Relativistic invariance, in turn, is a symmetry which derives from the structure of spacetime. So far, the perturbative attempt to formulate a fundamental local quantum field theory of gravity based on the metric field seems to be in conflict with at least one of these properties. In quantum Hořava gravity, a quantum Lifshitz field theory of gravity characterized by an anisotropic scaling between space and time, unitarity and renormalizability can be retained while Lorentz invariance is sacrificed at high energies and must emerge only as approximate symmetry at low energies. I review various approaches to perturbative quantum gravity with a particular focus on recent progress in the quantization of Hořava gravity, supporting its theoretical status as a unitary, renormalizable and ultraviolet-complete quantum theory of gravity.

    ↳ hep-thastro-ph.COgr-qchep-phFront. Phys., 21 July 2020·18 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.