Thu·May 31, 2018Thursday·May 31, 2018

1. 01*

   Actual Physics behind Mono-X

   Elias Bernreuther🇩🇪 · Jan Horak🇩🇪 · Tilman Plehn🇩🇪 · Anja Butter🇩🇪

   Mono-X searches are standard dark matter search strategies at the LHC. First, we show how in the case of initial state radiation they essentially collapse to mono-jet searches. Second, we systematically study mono-X signatures from decays of heavier dark matter states. Direct detection constraints strongly limit our MSSM expectations, but largely vanish for mono-Z and mono-Higgs signals once we include light NMSSM mediators. Finally, the decay topology motivates mono-W-pair and mono-Higgs-pair searches, strengthening and complementing their mono-X counterparts.

   hep-phSciPost Phys.(2018)·20 citations
2. 02*

   Imaging particle collision data for event classification using machine learning

   S. V. Chekanov🇺🇸

   We propose a method to organize experimental data from particle collision experiments in a general format which can enable a simple visualisation and effective classification of collision data using machine learning techniques. The method is based on sparse fixed-size matrices with single- and two-particle variables containing information on identified particles and jets. We illustrate this method using an example of searches for new physics at the LHC experiments.

   hep-phhep-exNucl.Instrum.Meth.A(2019)·14 citations
3. 03*

   Lorentz violation and the electron-ion collider

   Enrico Lunghi🇺🇸 · Nathan Sherrill🇺🇸

   We investigate the prospects for detecting violations of Lorentz symmetry in unpolarized deep inelastic electron-proton scattering in the context of the future electron-ion collider. Simulated differential cross-section data are used to place expected bounds on a class of quark-sector coefficients for Lorentz violation that induce sidereal time dependence in the scattering cross section. We find that, with $100{\mathrm{fb}}^{-1}$ of integrated luminosity, the expected bounds are in the $10^{-5}-10^{-7}$ range and are roughly two orders of magnitude stronger than those that can be extracted from existing HERA data. We also discuss the possibility of extracting bounds on the remaining time-independent coefficients.

   hep-phhep-exPRD(2018)·15 citations
4. 04*

   Probing relic neutrino decays with 21 cm cosmology

   Marco Chianese🇬🇧 · Pasquale Di Bari🇬🇧 · Kareem Farrag🇬🇧 · Rome Samanta🇬🇧

   We show how 21 cm cosmology can test relic neutrino radiative decays into sterile neutrinos. Using recent EDGES results, we derive constraints on the lifetime of the decaying neutrinos. If the EDGES anomaly will be confirmed, then there are two solutions, one for much longer and one for much shorter lifetimes than the age of the universe, showing how relic neutrino radiative decays can explain the anomaly in a simple way. We also show how to combine EDGES results with those from radio background observations, showing that potentially the ARCADE 2 excess can be also reproduced together with the EDGES anomaly within the proposed non-standard cosmological scenario. Our calculation of the specific intensity at the redshifts probed by EDGES can be also applied to the case of decaying dark matter and it also corrects a flawed expression appeared in previous literature.

   hep-phastro-ph.COPLB(2019)·61 citations
5. 05*

   Multi-Meson Model for the $D^{+}\to K^{+}{K}^{-}{K}^{+}$ decay amplitude

   R.T. Aoude🇩🇪 · P.C. Magalhães🇧🇷 · A.C. dos Reis🇧🇷 · M.R. Robilotta🇧🇷

   We propose a novel approach to describe the $D^{+}\to K^{+}{K}^{-}{K}^{+}$ decay amplitude, based on chiral effective Lagrangians, which can be used to extract information about $K\bar{K}$ scattering. Our trial function is an alternative to the widely used isobar model and includes both nonresonant three-body interactions and two-body rescattering amplitudes, based on coupled channels and resonances, for S- and P-waves with isospin $0$ and $1$. The latter are unitarized in the $K$-matrix approximation and represent the only source of complex phases in the problem. Free parameters are just resonance masses and coupling constants, with transparent physical meanings. The nonresonant component, given by chiral symmetry as a real polynomium, is an important prediction of the model, which goes beyond the (2+1) approximation. Our approach allows one to disentangle the two-body scalar contributions with different isospins, associated with the $f_0(980)$ and $a_0(980)$ channels. We show how the $K\bar{K}$ amplitude can be obtained from the decay $D^{+}\to K^{+}{K}^{-}{K}^{+}$ and discuss extensions to other three-body final states.

   hep-phhep-exPRD(2018)·26 citations
6. 06*

   Freeze-out of Strange Hadron in pp, pPb and PbPb Collisions at LHC Energies

   Kapil Saraswat🇮🇳 · Prashant Shukla🇮🇳 · Vineet Kumar🇮🇳 · Venktesh Singh🇮🇳

   In this article, we will present a systematic analysis of transverse momentum spectra of the strange hadron in different multiplicity events produced in pp collision at $\sqrt{s}$ = 7 TeV, pPb collision at $\sqrt{s_{NN}}$ = 5.02 TeV and PbPb collision at $\sqrt{s_{NN}}$ = 2.76 TeV. The differential freeze out scenario of strange hadron $K_s^0$ assumed while analyzing the data using a Tsallis distribution which is modified to include transverse flow. The $p_T$ distributions of strange hadron in different systems are characterized in terms of the parameters namely, Tsallis temperature ($T$), power ($n$) and average transverse flow velocity ($\beta$).

   hep-phnucl-thSpringer Proc.Phys.(2018)·0 citations
7. 07*

   Charged and Neutral Current Pion Production in Neutrino-Nucleus Scattering

   Kapil Saraswat🇮🇳 · Prashant Shukla🇮🇳 · Vineet Kumar🇮🇳 · Venktesh Singh🇮🇳

   In this article, we present the charged and neutral current coherent pion production in the neutrino-nucleus interaction in the resonance region using the formalism based on the partially conserved axial current (PCAC) theorem which relates the neutrino-nucleus cross section to the pion-nucleus elastic cross section. The pion nucleus elastic cross section is calculated using the Glauber model approach. We calculate the integrated cross sections for neutrino-carbon, neutrino-iron and neutrino-oxygen scattering. The results of integrated cross-section calculations are compared with the measured data

   hep-phnucl-thSpringer Proc.Phys.(2018)·0 citations
8. 08*

   Chiral physics in the magnetic field with quark confinement contribution

   M.A. Andreichikov🇷🇺 · Yu.A. Simonov🇷🇺

   The standard chiral perturbation theory is known to predict much weaker effects in magnetic field, than found in numerical lattice data. To overcome this disagreement we are using the effective chiral confinement Lagrangian, $L_{ECCL}$, containing both chiral and quark degrees of freedom, in the presence of external magnetic field. Without magnetic fields $L_{ECCL}$ reduces to the ordinary chiral Lagrangian $L_{ECL}$, yielding in the lowest order $O({\partial }_{\mu }\phi {)}^2$ all known relations, and providing explicit numerical coefficients in the higher $O(p^4,p^6)$ orders. The inclusion of the magnetic field in $L_{ECCL}$ strongly modifies ECL results for chiral condensates, coupling constants $f_{\pi },f_K$ and masses of chiral mesons. The resulting behavior contains the only parameter -- the string tension $\sigma$, is roughly proportional to $O\left(\frac{eB}{\sigma }\right)$ and agrees very well with lattice data. These results show that the magnetic field acts not only on the chiral degrees of freedom $({\phi }_{\pi })$, but also on quarks in the quark-chiral Lagrangian, which produce much stronger effect.

   hep-phEPJC(2018)·31 citations
9. 09*

   Combining QED and QCD transverse-momentum resummation for Z boson production at hadron colliders

   Leandro Cieri🇮🇹 · Giancarlo Ferrera🇮🇹 · German F. R. Sborlini🇮🇹

   We consider the transverse-momentum ($q_T$) distribution of $Z$ bosons produced in hadronic collisions. At small values of $q_T$, we perform the analytic resummation of the logarithmically enhanced QED contributions up to next-to-leading logarithmic accuracy, including the mixed QCD-QED contributions at leading logarithmic accuracy. Resummed results are consistently matched with the next-to-leading fixed-order results (i.e. $\mathcal{O}({\alpha }^2)$) at small, intermediate and large values of $q_T$. We combine the QED corrections with the known QCD results at next-to-next-to-leading order ($\mathcal{O}({\alpha }_S^2)$) and next-to-next-to-leading logarithmic accuracy. We show numerical results at LHC and Tevatron energies, studying the impact of the QED corrections and providing an estimate of the corresponding perturbative uncertainty. Our analytic results for the combined QED and QCD resummation, obtained through an extension of the $q_T$ resummation formalism in QCD, are valid for the production of generic neutral and colourless high-mass systems in hadronic collision.

   hep-phhep-exJHEP(2018)·62 citations
10. 10*

    Baryon number probability distribution at finite temperature

    Ke-xin Sun🇨🇳 · Rui Wen🇨🇳 · Wei-jie Fu🇨🇳

    The probability distribution of the net baryon number is investigated within the functional renormalization group approach. We find that the Roberge-Weiss periodicity related to the Z(3) symmetry of the gluon fields results directly in that, states of the net baryon number $N_B=N\pm 1/3$ with $N\in \mathbb{Z}$ are prohibited, and only those of $N_B=N$ are possible. By employing the probability distribution of the net baryon number, we also compute the cumulants of the baryon number distribution, which are found to be well consistent with those obtained from the generalized susceptibilities. A question about the relation between the color confinement and the probability distribution of net baryon number is put forward.

    hep-phnucl-thPRD(2018)·14 citations
11. 11*

    Prospects for the determination of the top-quark Yukawa coupling at future $e^{+}{e}^{-}$ colliders

    Stefano Boselli🇮🇹 · Ross Hunter🇬🇧 · Alexander Mitov🇬🇧

    We estimate the sensitivity to the top-quark Yukawa coupling $y_t$ at future $e^{+}{e}^{-}$ colliders. We go beyond the standard approach that focuses on $t\bar{t}h$ production and consider final states with a Higgs boson but not top quarks. The sensitivity to $y_t$ in such processes comes from the coupling of the Higgs boson to top quarks in loops. Such final states can be produced in significant numbers at center-of-mass energies that will be accessible by all proposed $e^{+}{e}^{-}$ colliders. In a simplified theoretical framework to parametrise deviations from the Standard Model, we find that at FCC-$ee$ and CEPC operating at $\sqrt{s}=240$ GeV, $y_t$ could potentially be measured with precision better than $1\%$. For CLIC and ILC the extraction of $y_t$ could be improved by a factor of about 2 and 7 respectively, compared to its extraction from just $t\bar{t}h$ final states.

    hep-phhep-exJ.Phys.G(2019)·19 citations
12. 12*

    The Platinum Channel: Higgs Decays to as many as 8 Leptons

    Eder Izaguirre🇺🇸 · Daniel Stolarski🇨🇦

    We propose a search for Higgs decays with as many as eight leptons in the final state. This signal can arise in a simple model with a hidden vector ($A_d$) that gets mass via a hidden scalar ($h_d$) vacuum expectation value. The 125 GeV Higgs can then decay $H\to h_d{h}_d\to 4A_d\to 8f$, where $f$ are Standard Model fermions. We recast current searches and show that a branching ratio of $H\to h_d{h}_d$ as large as 10% is allowed. We also describe a dedicated search that could place bounds on BR($H\to h_d{h}_d$) as low as $10^{-5}$ using only 36 fb${}^{-1}$ of data, with significant improvements coming from greater integrated luminosity.

    hep-phhep-exPRL(2018)·14 citations
13. 13*

    Coscattering/Coannihilation Dark Matter in a Fraternal Twin Higgs Model

    Hsin-Chia Cheng🇺🇸 · Lingfeng Li🇺🇸 · Rui Zheng🇺🇸

    Dark matter candidates arise naturally in many models that address the hierarchy problem. In the fraternal twin Higgs model which could explain the absence of the new physics signals at the Large Hadron Collider (LHC), there are several viable dark matter candidates. In this paper we study the twin neutrino in the mass range $\sim$ 0.1--10 GeV as the dark matter. The thermal relic density is determined by the interplay of several annihilation and scattering processes between the twin neutrino, twin tau, and twin photon, depending on the order of the freeze-out temperatures of these processes. Besides the common coannihilation scenario where the relic density is controlled by the twin tau annihilation, it can realize the recently discovered coscattering phase if the scattering of the twin neutrino into the twin tau freezes out earlier than the twin tau annihilation. We also provide a method to calculate the thermal relic density in the intermediate regime where both coannihilation and coscattering processes contribute to the determination of the dark matter density. We show that the right amount of dark matter can be obtained in various scenarios in different regions of the parameter space. The current experimental constraints and future probes into the parameter space from direct detections, cosmological and astrophysical bounds, dark photon searches, and displaced decays at colliders, are discussed.

    hep-phhep-exJHEP(2018)·58 citations
14. 14*

    Renormalization and ultraviolet sensitivity of gauge vertices in universal extra dimensions

    Ayres Freitas🇺🇸 · Daniel Wiegand🇺🇸

    When computing radiative corrections in models with compactified extra dimen- sions, one has to sum over the entire tower of Kaluza-Klein excitations inside the loops. The loop corrections generate a difference between the coupling strength of a zero-mode gauge boson and the coupling strength of its Kaluza-Klein excitation, although both originate from the same higher-dimensional gauge interaction. Furthermore, this dis- crepancy will in general depend on the cutoff scale and assumptions about the UV completion of the extra-dimensional theory. In this article, these effects are studied in detail within the context of the minimal universal extra dimension model (MUED). The broad features of the cutoff scale dependence can be captured through the so- lution of the functional flow equation in five-dimensional space. However, an explicit diagrammatic calculation reveals some modifications due to the compactification of the extra dimension. Nevertheless, when imposing a physical renormalization condition, one finds that the UV sensitivity of the effective Kaluza-Klein gauge-boson vertex is relatively small and not very important for most phenomenological purposes. Similar conclusions should hold in a larger class of extra-dimensional models besides MUED.

    hep-phJHEP(2018)·4 citations
15. 15*

    Universal behaviour, transients and attractors in supersymmetric Yang-Mills plasma

    Michał Spaliński🇵🇱

    Numerical simulations of expanding plasma based on the AdS/CFT correspondence as well as kinetic theory and hydrodynamic models strongly suggest that some observables exhibit universal behaviour even when the system is not close to local equilibrium. This leading behaviour is expected to be corrected by transient, exponentially decaying contributions which carry information about the initial state. Focusing on late times, when the system is already in the hydrodynamic regime, we analyse numerical solutions describing expanding plasma of strongly coupled N=4 supersymmetric Yang-Mills theory and identify these transient effects, matching them in a quantitative way to leading trans-series corrections corresponding to least-damped quasinormal modes of AdS black branes. In the process we offer additional evidence supporting the recent identification of the Borel sum of the hydrodynamic gradient expansion with the far-from-equilibrium attractor in this system.

    ↳ hep-thhep-phnucl-thPLB(2018)·25 citations
16. 16*

    Planckian signatures in optical harmonic generation and supercontinuum

    Claudio Conti🇮🇹

    Many theories of quantum gravity, as string theory, loop quantum gravity, and doubly special relativity, predict the existence of a minimal length scale and outline the need to generalize the uncertainty principle. This generalized uncertainty principle relies on modified commutation relations that - if applied to the second quantization - imply an excess energy of the electromagnetic quanta with respect to $\hslash \omega$. Here we show that this "dark energy of the photon" is amplified during nonlinear optical process. Therefore, if one accepts the minimal length scenario, one must expect to observe specific optical frequencies in optical harmonic generation by intense laser fields. Other processes as four-wave mixing and supercontinuum generation may also contain similar spectral features of quantum-gravity. Nonlinear optics may hence be helpful to falsify some of the most investigated approaches to the unification of quantum mechanics and general relativity.

    ↳ physics.opticsgr-qchep-phquant-ph1 citation
17. 17*

    Optical Ring Cavity Search for Axion Dark Matter

    Ippei Obata🇯🇵 · Tomohiro Fujita🇯🇵 · Yuta Michimura🇯🇵

    We propose a novel experiment to search for axion dark matter which differentiates the phase velocities of the left and right-handed polarized photons. Our optical cavity measures the difference of the resonant frequencies between two circular-polarizations of the laser beam. The design of our cavity adopts double-pass configuration to realize a null experiment and give a high common mode rejection of environmental disturbances. We estimate the potential sensitivity to the axion-photon coupling constant $g_{a\gamma }$ for the axion mass $m\lesssim 10^{-10}$ eV. In a low mass range $m\lesssim 10^{-15}$ eV, we can achieve $g_{a\gamma }\lesssim 3\times 10^{-16}{\text{GeV}}^{-1}$ which is beyond the current bound by several orders of magnitude.

    ↳ astro-ph.COastro-ph.IMhep-phphysics.ins-det+1PRL(2018)·138 citations
18. 18*

    Impact of EDGES 21cm Global Signal on Primordial Power Spectrum

    Shintaro Yoshiura🇯🇵 · Keitaro Takahashi🇯🇵 · Tomo Takahashi🇯🇵

    We investigate the impact of the recent observation of the 21cm global signal by EDGES on primordial power spectrum, particularly focusing on the running parameters ${\alpha }_s$ and ${\beta }_s$ which characterize the detailed scale dependence of the primordial spectrum. When primordial power spectrum is enhanced/suppressed on small scales, the structure formation proceeds faster/slower and changes the abundance of small size halos, which affects the sources of Lyman $\alpha$ radiation at high redshifts to alter the position of the absorption line. Recent observation of EDGES detected the 21cm absorption line at $z=17.2$ and this result also indicates that the brightness temperature is consistent with zero for $z\lesssim 14$ and $z\gtrsim 22$, which can exclude a scenario giving the absorption line at such redshifts. We argue that the bound on the running parameters can be obtained by requiring that the absorption line should not exceed observational bounds at such redshift ranges and found that some parameter space of ${\alpha }_s$ and ${\beta }_s$ allowed by Planck may be disfavored for some values of astrophysical parameters.

    ↳ astro-ph.COgr-qchep-phPRD(2018)·23 citations
19. 19*

    Observation of universal dynamics in a spinor Bose gas far from equilibrium

    Maximilian Prüfer🇩🇪 · Philipp Kunkel🇩🇪 · Helmut Strobel🇩🇪 · Stefan Lannig🇩🇪 · Daniel Linnemann🇩🇪 · Christian-Marcel Schmied🇩🇪 · Jürgen Berges🇩🇪 · Thomas Gasenzer🇩🇪 · Markus K. Oberthaler🇩🇪

    The dynamics of quantum systems far from equilibrium represents one of the most challenging problems in theoretical many-body physics. While the evolution is in general intractable in all its details, relevant observables can become insensitive to microscopic system parameters and initial conditions. This is the basis of the phenomenon of universality. Far from equilibrium, universality is identified through the scaling of the spatiotemporal evolution of the system, captured by universal exponents and functions. Theoretically, this has been studied in examples as different as the reheating process in inflationary universe cosmology, the dynamics of nuclear collision experiments described by quantum chromodynamics, or the post-quench dynamics in dilute quantum gases in non-relativistic quantum field theory. Here we observe the emergence of universal dynamics by evaluating spatially resolved spin correlations in a quasi one-dimensional spinor Bose-Einstein condensate. For long evolution times we extract the scaling properties from the spatial correlations of the spin excitations. From this we find the dynamics to be governed by transport of an emergent conserved quantity towards low momentum scales. Our results establish an important class of non-stationary systems whose dynamics is encoded in time independent scaling exponents and functions signaling the existence of non-thermal fixed points. We confirm that the non-thermal scaling phenomenon involves no fine-tuning, by preparing different initial conditions and observing the same scaling behaviour. Our analog quantum simulation approach provides the basis to reveal the underlying mechanisms and characteristics of non-thermal universality classes. One may use this universality to learn, from experiments with ultra-cold gases, about fundamental aspects of dynamics studied in cosmology and quantum chromodynamics.

    ↳ cond-mat.quant-gasgr-qchep-phquant-phNature(2018)·226 citations
20. 20*

    Dark energy in scalar-vector-tensor theories

    Ryotaro Kase🇯🇵 · Shinji Tsujikawa🇯🇵

    The scalar-vector-tensor theories with second-order equations of motion can accommodate both Horndeski and generalized Proca theories as specific cases. In the presence of a perfect fluid, we study the cosmology in such a most general scheme of scalar-vector-tensor theories with parity invariance by paying particular attention to the application to dark energy. We obtain a closed-form expression of the background equations of motion by using coefficients appearing in the second-order action of scalar perturbations. We also derive conditions for the absence of ghost and Laplacian instabilities of tensor and vector perturbations and show that the existence of matter does not substantially modify the stabilities of dynamical degrees of freedom in the small-scale limit. On the other hand, the sound speed of scalar perturbations is affected by the presence of matter. Employing the quasi-static approximation for scalar perturbations deep inside the sound horizon, we derive analytic expressions of Newtonian and weak lensing gravitational potentials as well as two scalar perturbations arising from the scalar and vector fields. We apply our general framework to dark energy theories with the tensor propagation speed equivalent to the speed of light and show that the observables associated with the growth of matter perturbations and weak lensing potentials are generally affected by intrinsic vector modes and by interactions between scalar and vector fields.

    ↳ gr-qcastro-ph.COhep-phhep-thJCAP(2018)·32 citations
21. 21*

    Rapidity scan in heavy ion collisions at $\sqrt{s_{\mathrm{NN}}}=72$~GeV using a viscous hydro + cascade model

    Iurii Karpenko🇫🇷

    In this note we discuss the rapidity dependence of the initial and final conditions for hydrodynamic evolution as well as the resulting basic hadronic observables in heavy ion collisions at $\sqrt{s_{\mathrm{NN}}}=72$ GeV in the framework of a viscous hydro+cascade model vHLLE+UrQMD. The resulting rapidity dependences are driven to a big extent by the initial state, which is simulated with the UrQMD cascade. The results can serve as a prediction for future experiments such as the AFTER@LHC or the BES-II program at STAR.

    ↳ nucl-thhep-phnucl-exActa Phys.Polon.B(2019)·14 citations
22. 22*

    Significant Excess of ElectronLike Events in the MiniBooNE Short-Baseline Neutrino Experiment

    MiniBooNE Collaboration · A. A. Aguilar-Arevalo · B. C. Brown · L. Bugel · G. Cheng · J. M. Conrad · R. L. Cooper · R. Dharmapalan · A. Diaz · Z. Djurcic · D. A. Finley · R. Ford and 36 other authors

    The MiniBooNE experiment at Fermilab reports results from an analysis of ${\nu }_e$ appearance data from $12.84\times 10^{20}$ protons on target in neutrino mode, an increase of approximately a factor of two over previously reported results. A ${\nu }_e$ charged-current quasielastic event excess of $381.2\pm 85.2$ events ($4.5\sigma$) is observed in the energy range $200<E_{\nu }^{QE}<1250$~MeV. Combining these data with the ${\bar{\nu }}_e$ appearance data from $11.27\times 10^{20}$ protons on target in antineutrino mode, a total ${\nu }_e$ plus ${\bar{\nu }}_e$ charged-current quasielastic event excess of $460.5\pm 99.0$ events ($4.7\sigma$) is observed. If interpreted in a two-neutrino oscillation model, ${\nu }_{\mu }\to {\nu }_e$, the best oscillation fit to the excess has a probability of $21.1\%$, while the background-only fit has a ${\chi }^2$ probability of $6\times 10^{-7}$ relative to the best fit. The MiniBooNE data are consistent in energy and magnitude with the excess of events reported by the Liquid Scintillator Neutrino Detector (LSND), and the significance of the combined LSND and MiniBooNE excesses is $6.0\sigma$. A two-neutrino oscillation interpretation of the data would require at least four neutrino types and indicate physics beyond the three neutrino paradigm.Although the data are fit with a two-neutrino oscillation model, other models may provide better fits to the data.

    ↳ hep-exhep-phPRL(2018)·754 citations
23. 23*

    Extragalactic photon--axion-like particle oscillations up to 1000 TeV

    Giorgio Galanti🇮🇹 · Marco Roncadelli🇮🇹

    Axion-like particles (ALPs) are attracting increasing interest since, among other things, they are a prediction of many extensions of the standard model of elementary particles physics and in particular of superstrings and superbranes. Remarkably, depending on the set of their parameter space, they strongly increase the photon transparency in the very-high energy band. The recent discovery of photon dispersion on the CMB requires a substantial modification of the previous picture: this is indeed the goal of the present paper. We compute the photon survival probability from a blazar to us exactly, and we plot it versus the observed energy for 7 simulated blazars at different $z$ and 4 values of a model parameter. Our predictions can be tested by the new generation of $\gamma$-ray observatories like CTA, HAWC, GAMMA-400, LHAASO, TAIGA-HiSCORE and HERD. Finally, for our guessed values of $m_a$ and $g_{\gamma \gamma a}$ our ALP can be detected in the upgrade of ALPS II at DESY, the planned experiments IAXO, STAX and ABRACADABRA as well as with other techniques.

    ↳ astro-ph.HEhep-phJHEAp(2018)·54 citations
24. 24*

    Is Anomaly Transferred thorough Multi-loop Process?

    Toshiki Nakawaki🇯🇵

    We investigated the multi-loop anomaly transfer to QCD sector from another one and its ability to solve strong CP problem. If the anomalous symmetry is spontaneously broken, its Nambu-Goldstone (NG) boson can couple to the QCD $G\tilde{G}$ through this transfer effect and behave as an axion. In our result, such a particle acquire mass pertabatively in fact, and really massless mode doesn't have couplings with $G\tilde{G}$. Consequently, this pseudo-NG boson is found not to solve the problem.

    ↳ hep-thhep-ph1 citation
25. 25*

    Can Long-Range Nuclear Properties Be Influenced By Short Range Interactions? A chiral dynamics estimate

    G.A. Miller🇺🇸 · A. Beck🇺🇸 · S. May-Tal Beck🇺🇸 · L.B. Weinstein🇺🇸 · E. Piasetzky🇮🇱 · O. Hen🇺🇸

    Recent experiments and many-body calculations indicate that approximately 20\% of the nucleons in medium and heavy nuclei ($A\ge 12$) are part of short-range correlated (SRC) primarily neutron-proton ($np$) pairs. We find that using chiral dynamics to account for the formation of $np$ pairs due to the effects of iterated and irreducible two-pion exchange leads to values consistent with the 20\% level. We further apply chiral dynamics to study how these correlations influence the calculations of nuclear charge radii, that traditionally truncate their effect, to find that they are capable of introducing non-negligible effects.

    ↳ nucl-thhep-phnucl-exPLB(2019)·35 citations
26. 26*

    Renormalised CFT 3-point functions of scalars, currents and stress tensors

    Adam Bzowski🇫🇷 · Paul McFadden🇬🇧 · Kostas Skenderis🇬🇧

    We discuss the renormalisation of mixed 3-point functions involving tensorial and scalar operators in conformal field theories of general dimension. In previous work we analysed correlators of either purely scalar or purely tensorial operators, in each case finding new features and new complications: for scalar correlators, renormalisation leads to beta functions, novel conformal anomalies of type B, and unexpected analytic structure in momentum space; for correlators of stress tensors and/or conserved currents, beta functions vanish but anomalies of both type B and type A (associated with a $0/0$ structure) are present. Mixed correlators combine all these features: beta functions and anomalies of type B, plus the possibility of new type A anomalies. Following a non-perturbative and general momentum-space analysis, we present explicit results in dimensions $d=3,4$ for all renormalised 3-point functions of stress tensors, conserved currents and scalars of dimensions $\Delta =d$ and $\Delta =d-2$. We identify all anomalies and beta functions, and explain the form of the anomalous conformal Ward identities. In $d=3$, we find a $0/0$ structure but the corresponding type A anomaly turns out to be trivial. In addition, the correlators of two currents and a scalar, and of two stress tensors and a scalar, both feature universal tensor structures that are independent of the scalar dimension and vanish for opposite helicities.

    ↳ hep-thcond-mat.str-elhep-phJHEP(2018)·138 citations
27. 27*

    A percent-level determination of the nucleon axial coupling from Quantum Chromodynamics

    Chia Cheng Chang🇺🇸 · Amy Nicholson🇺🇸 · Enrico Rinaldi🇺🇸 · Evan Berkowitz🇩🇪 · Nicolas Garron🇬🇧 · David A. Brantley🇺🇸 · Henry Monge-Camacho🇺🇸 · Christopher J. Monahan🇺🇸 · Chris Bouchard🇬🇧 · M.A. Clark🇺🇸 · Bálint Joó🇺🇸 · Thorsten Kurth🇺🇸 and 3 other authors

    The $\text{axial coupling of the nucleon}$, $g_A$, is the strength of its coupling to the $\text{weak}$ axial current of the Standard Model of particle physics, in much the same way as the electric charge is the strength of the coupling to the electromagnetic current. This axial coupling dictates the rate at which neutrons decay to protons, the strength of the attractive long-range force between nucleons and other features of nuclear physics. Precision tests of the Standard Model in nuclear environments require a quantitative understanding of nuclear physics rooted in Quantum Chromodynamics, a pillar of the Standard Model. The prominence of $g_A$ makes it a benchmark quantity to determine theoretically - a difficult task because quantum chromodynamics is non-perturbative, precluding known analytical methods. Lattice Quantum Chromodynamics provides a rigorous, non-perturbative definition of quantum chromodynamics that can be implemented numerically. It has been estimated that a precision of two percent would be possible by 2020 if two challenges are overcome: contamination of $g_A$ from excited states must be controlled in the calculations and statistical precision must be improved markedly. Here we report a calculation of $g_A^{QCD}=1.271\pm 0.013$, using an unconventional method inspired by the Feynman-Hellmann theorem that overcomes these challenges.

    ↳ hep-lathep-exhep-phnucl-ex+1Nature(2018)·237 citations
28. 28*

    Stability of Condensed Fuzzy Dark Matter Halos

    Joshua Eby🇮🇱 · Madelyn Leembruggen🇺🇸 · Peter Suranyi🇺🇸 · L.C.R. Wijewardhana🇺🇸

    Stability properties of gravitationally bound condensates composed of ultralight axionic Fuzzy Dark Matter (FDM) are studied. Previous work has shown that astrophysical collisions could make self-gravitating condensates structurally unstable, making them prone to collapse and decay; in the context of FDM, we reexamine the relevant timescales using the time-dependent variational method. We show that FDM condensates can be made unstable through gravitational interactions with central black holes, for black hole masses in a phenomenologically relevant range. Instability could also be stimulated by galaxy collisions. The subsequent decay takes place over a period lasting as long as many thousands of years. We also discuss the possible relevance of FDM condensates to understanding the composition of Ultracompact Dwarf (UCD) Galaxies. Future observation of extremely massive black holes in the central regions of UCDs can constrain this interpretation.

    ↳ astro-ph.COhep-phJCAP(2018)·15 citations
29. 29*

    Machine learning for bounce calculation

    Ryusuke Jinno🇰🇷

    We study the possibility of using machine learning for the calculation of the bounce action in quantum tunneling. Adopting supervised learning, we train neural network to give the bounce action from a given potential. It is found that, for one-dimensional tunneling, even a simple neural network performs at a percent level.

    ↳ hep-thhep-ph27 citations
30. 30*

    $\mathbf{\eta }$-${}^4\mathrm{He}$ interaction from the $\mathbf{dd}\to {\mathbf{\eta }}^4\mathrm{He}$ reaction near threshold

    Ju-Jun Xie🇨🇳 · Wei-Hong Liang🇨🇳 · Eulogio Oset🇪🇸

    We analyze the data on the total cross sections for the $dd\to \eta {}^4\mathrm{He}$ reaction close to threshold and look for possible ${\eta }^4\mathrm{He}$ bound states. We develop a framework in which the ${\eta }^4\mathrm{He}$ optical potential is the key ingredient, rather than parameterizing the scattering matrix, as is usually done. The strength of this potential, together with some production parameters, are fitted to the available experimental data. The relationship of the scattering matrix to the optical potential is established using the Bethe-Salpeter equation and the ${\eta }^4\mathrm{He}$ loop function incorporates the range of the interaction given by the experimental ${}^4\mathrm{He}$ density. However, when we look for poles of the scattering matrix, we get poles in the bound region, poles in the positive energy region or no poles at all. If we further restrict the results with constraints from a theoretical model with all its uncertainties the bound states are not allowed. However, we find a bump structure in $|T{|}^2$ of the ${\eta }^4\mathrm{He}\to {\eta }^4\mathrm{He}$ amplitude below threshold for the remaining solutions.

    ↳ nucl-thhep-phnucl-exEPJA(2019)·15 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.