Fri·Jul 13, 2018Friday·July 13, 2018

1. 01*

   Probing Higgs boson couplings in $t\bar{t}b\bar{b}$ production at the LHC

   Hoda Hesari🇮🇷

   In this paper, we investigate the effects of dimension six operators in the framework of the standard model (SM) effective field theory on using $t\bar{t}b\bar{b}$ channel at the LHC with the center-of-mass energy of 13 TeV. In this analysis, we only assume leptonic top-quarks. Once the events were simulated, the CMS-measured cross-section was used to constrain the corresponding effective Wilson coefficients at $95\%$ confidence level. Considering the SM effective Lagrangian, the $t\bar{t}b\bar{b}$ events in proton-proton collision were very sensitive to the effective Wilson coefficients ${\bar{C}}_g,\widetilde{C_g},{\bar{C}}_{uG},{\bar{C}}_{uW}$. We show that using $t\bar{t}b\bar{b}$ events, we can provide stronger constraints on these Wilson coefficients than the current ones obtained from other channels.

   hep-ph1 citation
2. 02*

   ${\eta }^{\prime }\to \eta \pi \pi$ decays in unitarized resonance chiral theory

   Sergi Gonzàlez-Solís🇨🇳 · Emilie Passemar🇺🇸

   We study the hadronic ${\eta }^{\prime }\to \eta \pi \pi$ decays within the framework of $U(3{)}_L\otimes U(3{)}_R$ Chiral Perturbation Theory including resonance states and the complete one-loop corrections. The amplitude is projected in partial waves and unitarized by means of the $N/D$ method resumming both the important $S$-and $D$-wave $\pi \pi$ and the subleading $S$-wave $\pi \eta$ final-state interactions. The participating scalar multiplet mass and coupling strengths are determined from fits to the Dalitz plot experimental data recently released by the A2 collaboration. As a byproduct of our analysis, the associated Dalitz-plot slope parameters are found to be $a=-0.072(7{)}_{\mathrm{stat}}(8{)}_{\mathrm{syst}},b=-0.052(1{)}_{\mathrm{stat}}(2{)}_{\mathrm{syst}},d=-0.051(8{)}_{\mathrm{stat}}(6{)}_{\mathrm{syst}}$, which lie in the ballpark of the current experimental and theoretical determinations.

   hep-phhep-exnucl-thEPJC(2018)·26 citations
3. 03*

   Resonance-aware subtraction in the dipole method

   Stefan Höche🇺🇸 · Sebastian Liebschner🇩🇪 · Frank Siegert🇩🇪

   We present a technique for infrared subtraction in next-to-leading order QCD calculations that preserves the virtuality of resonant propagators. The approach is based on the pseudo-dipole subtraction method proposed by Catani and Seymour in the context of identified particle production. As the first applications, we compute the ee > WWbb and pp > WWjbjb cross-section, which are both dominated by top-quark pair production above the threshold. We compare the efficiency of our approach with a calculation performed using the standard dipole subtraction technique.

   hep-phEPJC(2019)·11 citations
4. 04*

   Exclusive production of $J/\psi +{\eta }_c$ at the $B$ factories Belle and Babar using the principle of maximum conformality

   Zhan Sun🇨🇳 · Xing-Gang Wu🇨🇳 · Yang Ma🇺🇸 · Stanley J. Brodsky🇺🇸

   We predict the rate for exclusive double-charmonium production in electron-positron annihilation $e^{+}{e}^{-}\to J/\psi +{\eta }_c$ using perturbative quantum chromodynamics and the NRQCD framework for hard, heavy-quarkonium exclusive processes. The cross sections measured at the $B$-factories Belle and Babar at $\sqrt{s}=10.6$ GeV disagree with the pQCD leading-order predictions by an order of magnitude. The predictions at next-to-leading order are, however, very sensitive to the choice of the renormalization scale, resulting in an apparent discrepancy between the theoretical prediction and the data. We show that this discrepancy can in fact be eliminated by applying the Principle of Maximum Conformality (PMC) to set the renormalization scale. ... By carefully applying the PMC to different topologies of the annihilation process, one achieves precise pQCD predictions, together with improved perturbative convergence. We also observe that the single-photon-fragmentation QED correction is important, an effect which increases the total cross-section by about $10\%$. The scale-fixed, scheme-independent cross-section predicted by the PMC is ${\sigma }_{\mathrm{tot}}{|}_{\mathrm{PMC}}=20.35_{-3.8}^{+3.5}$ fb, where the uncertainties come from the squared average of the errors due to the value of the charm mass and the uncertainty from the quarkonium wavefunctions at the origin. We find that the typical momentum flow of the process is $2.30$ GeV, which explains the guessed choice of $2-3$ GeV using conventional scale-setting. The scale-fixed $e^{+}{e}^{-}\to J/\psi +{\eta }_c$ cross-section predicted by the PMC shows excellent agreement with the Belle and Babar measurements, emphasizing the importance of a rigorous renormalization scale-setting procedure.

   hep-phPRD(2018)·24 citations
5. 05*

   $\pi \pi \to K\bar{K}$ scattering up to 1.47 GeV with hyperbolic dispersion relations

   J.R. Pelaez🇪🇸 · A. Rodas (U. Complutense de Madrid)🇪🇸

   In this work we provide a dispersive analysis of $\pi \pi \to K\bar{K}$ scattering. For this purpose we present a set of partial-wave hyperbolic dispersion relations using a family of hyperbolas that maximizes the applicability range of the hyperbolic dispersive representation, which we have extended up to 1.47 GeV. We then use these equations first to test simple fits to different and often conflicting data sets, also showing that some of these data and some popular parameterizations of these waves fail to satisfy the dispersive analysis. Our main result is obtained after imposing these new relations as constraints on the data fits. We thus provide simple and precise parameterizations for the S, P and D waves that describe the experimental data from $K\bar{K}$ threshold up to 2 GeV, while being consistent with crossing symmetric partial-wave dispersion relations up to their maximum applicability range of 1.47 GeV. For the $S$-wave we have found that two solutions describing two conflicting data sets are possible. The dispersion relations also provide a representation for $S$, $P$ and $D$ waves in the pseudo-physical region.

   hep-phEPJC(2018)·72 citations
6. 06*

   Holographic Gauged NJL Model: the Conformal Window and Ideal Walking

   Kazem Bitaghsir Fadafan🇮🇷 · Will Clemens🇬🇧 · Nick Evans🇬🇧

   We study the holographic Dynamic AdS/QCD description of a SU($N_c$) non-abelian gauge theory with $N_f$ fermions in the fundamental representation which also have Nambu-Jona-Lasinio interactions included using Witten's multi-trace prescription. In particular here we study aspects of the dynamics in and near the conformal window of the gauge theory as described by the two loop running of the gauge theory. If the number of flavours is such that the IR fixed point lies with the anomalous dimension, $\gamma$, of the quark bilinear above one then chiral symmetry breaking occurs. Here we display a spiral in the mass - quark condensate plane describing a sequence of unstable excited states of the vacuum. An attractive NJL operator enhances the vacuum condensate but only an infinitely repulsive NJL interaction switches off the condensation completely. When $N_f$ changes so that the IR fixed point falls below one (the conformal window region) there is a numerical discontinuity in the phase structure with condensation only occurring with a super critical NJL interaction. In the conformal window, the running of $\gamma$ to a non-trivial IR fixed point is similar to walking dynamics, although chiral symmetry breaking is not triggered. In the "Ideal Walking" scenario, chiral symmetry is broken in that IR conformal regime by the NJL interaction, but the change in $\gamma$ enhances the UV condensate. That enhancement of the condensate is shown in an analytic model with a sharp change in $\gamma$ and we show equivalent numerical results for the case of the two loop running. In the model the $\sigma$ becomes massless as the gauge theory running becomes near conformal and we show it is possible to realize a light higgs-like state in Ideal Walking models.

   hep-phhep-thPRD(2018)·17 citations
7. 07*

   An inverse seesaw model with natural hierarchy at TeV scale

   Takaaki Nomura🇰🇷 · Hiroshi Okada🇰🇷

   We propose a new kind of inverse seesaw model without any additional symmetries. Instead of the symmetries, we introduce several fermions and bosons with higher $SU(2{)}_L$ representations. After formulating the Higgs sector and neutrino sector, we show that the cut-off energy, which is valid to our model, is at around TeV scale, by examining behavior of $SU(2{)}_L$ gauge coupling. Then we show the testability of our model at collider physics.

   hep-phPRD(2019)·15 citations
8. 08*

   Threshold resummation in rapidity for colorless particle production at LHC

   Pulak Banerjee🇮🇳 · Goutam Das🇩🇪 · Prasanna K. Dhani🇮🇳 · V. Ravindran🇮🇳

   We present a formalism to resum large threshold logarithms to all orders in perturbative QCD for the rapidity distribution of any colorless particle at the hadron colliders. Using the derived resummed coefficients in two dimensional Mellin space, we present the rapidity distributions for the Higgs as well as for the Drell-Yan production to NNLO+NNLL accuracy at the LHC. The resummed distributions give stable prediction against the variation of unphysical renormalisation and factorisation scales in both the cases. Perturbative convergence is also improved with the inclusion of the resummed result.

   hep-phPoS(2018)·4 citations
9. 09*

   Electrodisintegration of Deuteron into Dark Matter and Proton Close to Threshold

   A. N. Ivanov🇦🇹 · R. Höllwieser🇦🇹 · N. I. Troitskaya🇦🇹 · M. Wellenzohn🇦🇹 · Ya. A. Berdnikov🇷🇺

   We discuss an investigation of the dark matter decay modes of the neutron, proposed by Fornal and Grinstein (Phys. Rev. Lett. 120 191801 (2018)) and Ivanov et al. ( arXiv:1806.10107 [hep-ph]) for solution of the neutron lifetime anomaly problem, through the analysis of the electrodisintegration of the deuteron d into dark matter fermions chi and protons p close to threshold. We calculate the triple-differential cross section for the reaction e^- + d ->\chi + p + e^- and propose to search for such a dark matter channel in coincidence experiments on the electrodisintegration of the deuteron e^- + d -> n + p + e^- into neutrons n and protons close to threshold with outgoing electrons, protons and neutrons in coincidence. A missing of neutron signals should testify a detection of dark matter fermions.

   hep-phgr-qchep-exnucl-exSymmetry(2021)·5 citations
10. 10*

    Criticality and dominance of axion physics in highly magnetized vacuum

    Selym Villalba-Chávez🇩🇪 · Anatoly E. Shabad🇷🇺 · Carsten Müller🇩🇪

    In a constant and homogeneous magnetic background, quantum vacuum fluctuations due to axion-like fields can dominate over those associated with the electron-positron fields. Considering the framework of axion-electrodynamics, the self-energy operator for the electromagnetic field is determined with an accuracy to second-order in the axion-diphoton coupling. This outcome is utilized for establishing modifications to the propagation characteristics of photons and to the Coulomb potential of a static pointlike charge. Notably, in the magnetosphere of a neutron star, the effect of photon capture by the magnetic field, known in QED as relating to gamma-quanta, is extended in axion electrodynamics to include X-ray photons with the result that a specially polarized part of the heat radiation from the surface is canalized along the magnetic field. Besides, for field strengths larger than the critical scale associated with this theory, the modified Coulomb potential is of Yukawa-type in the direction perpendicular to the magnetic field at distances much smaller than the Compton wavelength of an axion, while along the field it follows approximately the Coulomb law at any length scale. We find that at unlimitedly large magnetic fields the longstanding problem -- overcome in QED -- that the ground-state energy of a hydrogen atom is unbounded from below, is reinstated. However, in axion-electrodynamics this unboundedness is cut off because the largest magnetic field treatable within this theory is limited by the unitarity of the associated scattering matrix.

    hep-phEPJC(2021)·3 citations
11. 11*

    Proof of Color Octet NRQCD Factorization of P-Wave Heavy Quarkonium Production at All Orders in Coupling Constant

    Gouranga C Nayak🇺🇸

    Recently we have proved color octet NRQCD factorization of S-wave heavy quarkonium production at all orders in coupling constant at high energy colliders in Eur. Phys. J. C76 (2016) 448. In this paper we extend this to prove color octet NRQCD factorization of P-wave heavy quarkonium production at all orders in coupling constant at high energy colliders. We find that while the color octet NRQCD S-wave non-perturbative matrix element contains two gauge-links in the adjoint representation of SU(3), the color octet NRQCD P-wave non-perturbative matrix element contains four gauge-links in the fundamental representation of SU(3).

    hep-phnucl-th1 citation
12. 12*

    Fusing Vectors into Scalars at High Energy Lepton Colliders

    Dario Buttazzo🇮🇹 · Diego Redigolo🇮🇱 · Filippo Sala🇩🇪 · Andrea Tesi🇮🇹

    We study vector boson fusion production of new scalar singlets at high energy lepton colliders. We find that CLIC has the potential to test single production cross-sections of a few tens of attobarns in di-Higgs and di-boson final states. In models with a sizeable singlet-Higgs mixing, these values correspond to a precision in Higgs couplings of order 0.1% or better. We compare our sensitivities with those of the LHC and interpret our results in well-motivated models like the Twin Higgs, the NMSSM and axion-like particles. Looking forward to even higher energy machines, we show that the reach of muon colliders like LEMMA or MAP overcomes the one of future hadron machines like FCC-hh. We finally study the pair production of the new scalar singlets via an off-shell Higgs. This process does not vanish for small mixings and will constitute a crucial probe of models generating a first order electro-weak phase transition.

    hep-phhep-exJHEP(2018)·149 citations
13. 13*

    Right-handed Neutrinos and $R(D^{(\ast )})$

    Dean J. Robinson🇺🇸 · Bibhushan Shakya🇺🇸 · Jure Zupan🇺🇸

    We explore scenarios where the $R(D^{(\ast )})$ anomalies arise from semitauonic decays to a right-handed sterile neutrino. We perform an EFT study of all five simplified models capable of generating at tree-level the lowest dimension electroweak operators that give rise to this decay. We analyze their compatibility with current $R(D^{(\ast )})$ data and other relevant hadronic branching ratios, and show that one simplified model is excluded by this analysis. The remainder are compatible with collider constraints on the mediator semileptonic branching ratios, provided the mediator mass is of order TeV. We also discuss the phenomenology of the sterile neutrino itself, which includes possibilities for displaced decays at colliders and direct searches, measurable dark radiation, and gamma ray signals.

    hep-phJHEP(2019)·88 citations
14. 14*

    The Lund Jet Plane

    Frederic A. Dreyer🇺🇸 · Gavin P. Salam🇨🇭 · Gregory Soyez🇫🇷

    Lund diagrams, a theoretical representation of the phase space within jets, have long been used in discussing parton showers and resummations. We point out that they can be created for individual jets through repeated Cambridge/Aachen declustering, providing a powerful visual representation of the radiation within any given jet. Concentrating here on the primary Lund plane, we outline some of its analytical properties, highlight its scope for constraining Monte Carlo simulations and comment on its relation with existing observables such as the $z_g$ variable and the iterated soft-drop multiplicity. We then examine its use for boosted electroweak boson tagging at high momenta. It provides good performance when used as an input to machine learning. Much of this performance can be reproduced also within a transparent log-likelihood method, whose underlying assumption is that different regions of the primary Lund plane are largely decorrelated. This suggests a potential for unique insight and experimental validation of the features being used by machine-learning approaches.

    hep-phhep-exJHEP(2018)·267 citations
15. 15*

    Top tagging : an analytical perspective

    Mrinal Dasgupta🇬🇧 · Marco Guzzi🇺🇸 · Jacob Rawling🇬🇧 · Gregory Soyez🇫🇷

    In this paper we study aspects of top tagging from first principles of QCD. We find that the method known as the CMS top tagger becomes collinear unsafe at high $p_t$ and propose variants thereof which are IRC safe, and hence suitable for analytical studies, while giving a comparable performance to the CMS tagger. We also develop new techniques to identify three-pronged jet substructure, based on adaptations of the Y-splitter method and its combination with grooming. A novel feature of our studies, relative to previous calculations of two-pronged substructure, is our use of triple-collinear splitting functions, which owes to the presence of two mass scales of the same order, $m_t$ and $m_W$, in the signal jet. We carry out leading logarithmic resummed calculations for the various top-taggers, for both background and signal jets, and compare the results to those from parton showers. We also identify and comment on the main features driving tagger performance at high $p_t$ and discuss the role of non-perturbative effects.

    hep-phJHEP(2018)·12 citations
16. 16*

    Half-quantum vortices and walls bounded by strings in the polar-distorted phases of topological superfluid ${}^3$He

    J.T. Mäkinen🇫🇮 · V.V. Dmitriev🇷🇺 · J. Nissinen🇫🇮 · J. Rysti🇫🇮 · G.E. Volovik🇫🇮 · A.N. Yudin🇷🇺 · K. Zhang🇫🇮 · V.B. Eltsov🇫🇮

    Symmetries of the physical world have guided formulation of fundamental laws, including relativistic quantum field theory and understanding of possible states of matter. Topological defects (TDs) often control the universal behavior of macroscopic quantum systems, while topology and broken symmetries determine allowed TDs. Taking advantage of the symmetry-breaking patterns in the phase diagram of nanoconfined superfluid ${}^3$He, we show that half-quantum vortices (HQVs) -- linear topological defects carrying half quantum of circulation -- survive transitions from the polar phase to other superfluid phases with polar distortion. In the polar-distorted A phase, HQV cores in 2D systems should harbor non-Abelian Majorana modes. In the polar-distorted B phase, HQVs form composite defects -- walls bounded by strings hypothesized decades ago in cosmology. Our experiments establish the superfluid phases of ${}^3$He in nanostructured confinement as a promising topological media for further investigations ranging from topological quantum computing to cosmology and grand unification scenarios.

    ↳ cond-mat.othergr-qchep-phNature Commun.(2019)·44 citations
17. 17*

    Anisotropic hydrodynamic modeling of 200 GeV Au-Au collisions

    Dekrayat Almaalol🇺🇸 · Mubarak Alqahtani🇸🇦 · Michael Strickland🇺🇸

    We compare phenomenological results from 3+1d quasiparticle anisotropic hydrodynamics (aHydroQP) with experimental data collected in RHIC 200 GeV Au-Au collisions. We present comparisons of identified particle spectra in different centrality clases, charged particle multiplicity versus pseudorapidity, identified particle multiplicity versus centrality across a wide range of particle species, identified particle elliptic flow versus transverse momentum, and charged particle elliptic flow as a function of transverse momentum and rapidity. We use the same aHydroQP and hadronic production/feed down codes that were used previously to describe LHC 2.76 TeV data. The aHydroQP hydrodynamic model includes the effects of both shear and bulk viscosities in addition to an infinite number of transport coefficients computed self-consistently in the relaxation time approximation. To convert to the final state hadrons, we use anisotropic Cooper-Frye freeze-out performed on a fixed-energy-density hypersurface and compute the production/feed down using a customized version of Therminator 2. We find good agreement with many heavy-ion collision observables using only smooth Glauber initial conditions parameterized by an initial central temperature of T_0 = 455 MeV, a constant shear viscosity to entropy density ratio eta/s= 0.179, and a switching (freeze-out) temperature of T_FO=130 MeV.

    ↳ nucl-thhep-phPRC(2019)·46 citations
18. 18*

    Dark energy as a remnant of inflation and electroweak symmetry breaking

    Konstantinos Dimopoulos🇬🇧 · Tommi Markkanen🇬🇧

    It is shown that dark energy can be obtained from the interplay of the Higgs boson and the inflaton. A key element is the realization that electroweak symmetry breaking can trigger a second phase of rolling of the inflaton, which, when provided with the appropriate couplings between the fields, can be sufficiently slow to source accelerated expansion in the late time Universe. The observed dark energy density is obtained without fine-tuning of parameters or initial conditions due to an intricate conspiracy of numbers related to inflation, gravity and electroweak physics.

    ↳ astro-ph.COgr-qchep-phJHEP(2019)·17 citations
19. 19*

    The string swampland constraints require multi-field inflation

    Ana Achúcarro🇳🇱 · Gonzalo A. Palma🇨🇱

    An important unsolved problem that affects practically all attempts to connect string theory to cosmology and phenomenology is how to distinguish effective field theories belonging to the string landscape from those that are not consistent with a quantum theory of gravity at high energies (the "string swampland"). It was recently proposed that potentials of the string landscape must satisfy at least two conditions, the "swampland criteria", that severely restrict the types of cosmological dynamics they can sustain. The first criterion states that the (multi-field) effective field theory description is only valid over a field displacement $\Delta \varphi \le \Delta \sim \mathcal{O}(1)$ (in units where the Planck mass is 1), measured as a distance in the target space geometry. A second, more recent, criterion asserts that, whenever the potential $V$ is positive, its slope must be bounded from below, and suggests $|\nabla V|/V\ge c\sim \mathcal{O}(1)$. A recent analysis concluded that these two conditions taken together practically rule out slow-roll models of inflation. In this note we show that the two conditions rule out inflationary backgrounds that follow geodesic trajectories in field space, but not those following curved, non-geodesic, trajectories (which are parametrized by a non-vanishing bending rate $\Omega$ of the multi-field trajectory). We derive a universal lower bound on $\Omega$ (relative to the Hubble parameter $H$) as a function of $\Delta ,c$ and the number of efolds $N_e$, assumed to be at least of order 60. If later studies confirm $c$ and $\Delta$ to be strictly $\mathcal{O}(1)$, the bound implies strong turns with $\Omega /H\ge 3N_e\sim 180$. Slow-roll inflation in the landscape is not ruled out, but it is strongly multi-field.

    ↳ hep-thastro-ph.COgr-qchep-phJCAP(2019)·263 citations
20. 20*

    Axial Ward identity and the Schwinger mechanism -- Applications to the real-time chiral magnetic effect and condensates

    Patrick Copinger🇯🇵 · Kenji Fukushima🇯🇵 · Shi Pu🇯🇵

    We elucidate chirality production under parity breaking constant electromagnetic fields, with which we clarify qualitative differences in and out of equilibrium. For a strong magnetic field the pair production from the Schwinger mechanism increments the chirality. The pair production rate is exponentially suppressed with mass according to the Schwinger formula, while the mass dependence of chirality production in the axial Ward identity appears in the pesudo-scalar term. We demonstrate that in equilibrium field theory calculus the axial anomaly is canceled by the pseudo-scalar condensate for any mass. In a real-time formulation with in- and out-states, we show that the axial Ward identity leads to the chirality production rate consistent with the Schwinger formula. We illuminate that such an in- and out-states formulation makes clear the chiral magnetic effect in and out of equilibrium, and we discuss further applications to real-time condensates.

    ↳ hep-thcond-mat.str-elhep-phPRL(2018)·60 citations
21. 21*

    Dissecting the region around IceCube-170922A: the blazar TXS 0506+056 as the first cosmic neutrino source

    P. Padovani🇩🇪 · P. Giommi🇮🇹 · E. Resconi🇩🇪 · T. Glauch🇩🇪 · B. Arsioli🇧🇷 · N. Sahakyan🇦🇲 · M. Huber🇩🇪

    We present the dissection in space, time, and energy of the region around the IceCube-170922A neutrino alert. This study is motivated by: (1) the first association between a neutrino alert and a blazar in a flaring state, TXS 0506+056; (2) the evidence of a neutrino flaring activity during 2014 - 2015 from the same direction; (3) the lack of an accompanying simultaneous $\gamma$-ray enhancement from the same counterpart; (4) the contrasting flaring activity of a neighbouring bright $\gamma$-ray source, the blazar PKS 0502+049, during 2014 - 2015. Our study makes use of multi-wavelength archival data accessed through Open Universe tools and includes a new analysis of Fermi-LAT data. We find that PKS 0502+049 contaminates the $\gamma$-ray emission region at low energies but TXS 0506+056 dominates the sky above a few GeV. TXS 0506+056, which is a very strong (top percent) radio and $\gamma$-ray source, is in a high $\gamma$-ray state during the neutrino alert but in a low though hard $\gamma$-ray state in coincidence with the neutrino flare. Both states can be reconciled with the energy associated with the neutrino emission and, in particular during the low/hard state, there is evidence that TXS 0506+056 has undergone a hadronic flare with very important implications for blazar modelling. All multi-messenger diagnostics reported here support a single coherent picture in which TXS 0506+056, a very high energy $\gamma$-ray blazar, is the only counterpart of all the neutrino emissions in the region and therefore the most plausible first non-stellar neutrino and, hence, cosmic ray source.

    ↳ astro-ph.HEastro-ph.GAhep-exhep-phMNRAS(2018)·179 citations
22. 22*

    Neutron stars and stellar mergers as a laboratory for dense QCD matter

    Aleksi Vuorinen🇫🇮

    Neutron star observations, including direct mass and radius measurements as well as the analysis of gravitational wave signals emitted by stellar mergers, provide valuable and unique insights into the properties of strongly interacting matter at high densities. In this proceedings contribution, I review recent efforts to systematically constrain the equation of state (EoS) of dense nuclear and quark matter using a combination of ab initio particle and nuclear physics calculations and astrophysical data. In particular, I discuss the constraints that the gravitational wave observation GW170817 has placed on the EoS, and comment on the future prospects of improving the accuracy, to which this quantity is known.

    ↳ nucl-thhep-phNPA(2019)·16 citations
23. 23*

    Violation of the equivalence principle from light scalar dark matter

    A. Hees🇫🇷 · O. Minazzoli🇲🇨 · E. Savalle🇫🇷 · Y. V. Stadnik🇩🇪 · P. Wolf🇫🇷

    In this paper, we study the local observational consequences of a violation of the Einstein Equivalence Principle induced by models of light scalar Dark Matter (DM). We focus on two different models where the scalar field couples linearly or quadratically to the standard model of matter fields. For both these cases, we derive the solutions of the scalar field. We also derive from first principles the expressions for two types of observables: (i) the local comparison of two atomic sensors that are differently sensitive to the constants of Nature and (ii) the local differential acceleration between two test-masses with different compositions. For the linear coupling, we recover that the signatures induced by DM on both observables are the sum of harmonic and Yukawa terms. For the quadratic coupling on the other hand, the signatures derived for both types of observables turn out to be a sum of a time independent term and of an harmonic oscillation, whose amplitudes both depend on the position. Such a behavior is new and can make experiments in space more sensitive than terrestrial ones. Besides, the observables present some interesting non-linear behaviors that are due to the amplification or to the screening of the scalar-field, depending on the parameters of the theory, and on the compactness of the source of the gravitational field. Finally, we infer the various limits on the DM coupling parameters by using existing frequency comparisons on the one hand and tests of the universality of free fall on the ground (torsion balances) or in space (MICROSCOPE mission) on the other hand. We show that in the quadratic case, so-called natural parameters are still allowed by observations.

    ↳ gr-qchep-phphysics.atom-phPRD(2018)·226 citations
24. 24*

    Eta and Etaprime Photoproduction on the Nucleon with the Isobar Model EtaMAID2018

    L. Tiator🇩🇪 · M. Gorchtein🇩🇪 · V. L. Kashevarov🇩🇪 · K. Nikonov🇩🇪 · M. Ostrick🇩🇪 · M. Hadzimehmedovic🇧🇦 · R. Omerovic🇧🇦 · H. Osmanovic🇧🇦 · J. Stahov🇧🇦 · A. Svarc🇭🇷

    The isobar model EtaMAID has been updated with new and high precision data for eta and etaprime photoproduction on protons and neutrons from MAMI, ELSA, GRAAL and CLAS. The background is described in a recently developed Regge-cut model, and for the resonance part the whole list of nucleon resonances has been investigated with 21 N* states contributing to eta photoproduction and 12 N* states contributing to etaprime photoproduction. A new approach is discussed to avoid double counting in the overlap region of Regge and resonances. A comparison is done among four newly updated partial waves analyses for observables and partial waves. Finally, the possibility of a narrow resonance near W=1900 MeV is discussed, that would be able to explain unexpected energy and angular dependence of observables in p(gamma,etaprime)p near etaprime threshold.

    ↳ nucl-thhep-phnucl-exEPJA(2018)·68 citations
25. 25*

    The nuclear configurational entropy approach to dynamical QCD effects

    Gayane Karapetyan🇧🇷

    This paper scrutinizes the dynamical QCD effects influence on mesons, namely, the mean-square root radius of a pion in the holographic light-front wave function setup, in the context of the AdS/QCD. The nuclear configurational entropy, associated to mesonic holographic light-front wave functions, is shown to have a critical point that optimizes the two parameters of the spin-improved light-front wave function. The mean-square root pion radius and its cross-section, computed upon these derived values, match the exact existing experimental data to the precision of 0.14\%, below the experimental error at the PDG.

    ↳ nucl-thhep-phPLB(2018)·50 citations
26. 26*

    Non-linear Breit-Wheeler process in short laser double-pulses

    A. I. Titov🇷🇺 · B. Kampfer🇩🇪 · H. Takabe🇩🇪

    The non-linear (strong-field) Breit-Wheeler $e^{+}{e}^{-}$ pair production by a probe photon traversing two consecutive short and ultra short (sub-cycle) laser pulses is considered within a QED framework. The temporal shape of the pulses and the distance between them are essential for the differential cross section as a function of the azimuthal angle distribution of the outgoing electron (positron). The found effect of a pronounced azimuthal anisotropy is important for sub-cycle pulses and decreases rapidly with increasing width of the individual pulses.

    ↳ physics.plasm-phhep-phPRD(2018)·36 citations
27. 27*

    Quantum entanglement in the initial and final state of relativistic heavy ion collisions

    Rene Bellwied🇺🇸

    The possibility of quantum entanglement leading to a seemingly thermal distribution of the initial partonic state that maps to the final hadronic state in the evolution of the deconfined phase generated in relativistic heavy ion collisions is discussed in the context of early thermalization and final state particle distributions obtained in experiments at RHIC and the LHC.

    ↳ nucl-thhep-phnucl-exJ.Phys.Conf.Ser.(2018)·16 citations
28. 28*

    Bias due to neutrinos must not uncorrect'd go

    Sunny Vagnozzi🇸🇪 · Thejs Brinckmann🇩🇪 · Maria Archidiacono🇩🇪 · Katherine Freese🇸🇪 · Martina Gerbino🇸🇪 · Julien Lesgourgues🇩🇪 · Tim Sprenger🇩🇪

    In cosmologies with massive neutrinos, the galaxy bias defined with respect to the total matter field (cold dark matter, baryons, and non-relativistic neutrinos) depends on the sum of the neutrino masses $M_{\nu }$, and becomes scale-dependent even on large scales. This effect has been usually neglected given the sensitivity of current surveys, but becomes a severe systematic for future surveys aiming to provide the first detection of non-zero $M_{\nu }$. The effect can be corrected for by defining the bias with respect to the density field of cold dark matter and baryons instead of the total matter field. In this work, we provide a simple prescription for correctly mitigating the neutrino-induced scale-dependent bias effect in a practical way. We clarify a number of subtleties regarding how to properly implement this correction in the presence of redshift-space distortions and non-linear evolution of perturbations. We perform a MCMC analysis on simulated galaxy clustering data that match the expected sensitivity of the \textit{Euclid} survey. We find that the neutrino-induced scale-dependent bias can lead to important shifts in both the inferred mean value of $M_{\nu }$, as well as its uncertainty. We show how these shifts propagate to other cosmological parameters correlated with $M_{\nu }$, such as the cold dark matter physical density ${\Omega }_{cdm}{h}^2$ and the scalar spectral index $n_s$. In conclusion, we find that correctly accounting for the neutrino-induced scale-dependent bias will be of crucial importance for future galaxy clustering analyses. We encourage the cosmology community to correctly account for this effect using the simple prescription we present in our work. The tools necessary to easily correct for the neutrino-induced scale-dependent bias will be made publicly available in an upcoming release of the Boltzmann solver \texttt{CLASS}.

    ↳ astro-ph.COhep-phJCAP(2018)·92 citations
29. 29*

    Hybrid model with dynamical sources for heavy-ion collisions at BES energies

    Lipei Du🇺🇸 · Ulrich Heinz🇺🇸 · Gojko Vujanovic🇺🇸

    We develop a (3+1)-dimensional hybrid evolution model for heavy-ion collisions with dynamical sources for the energy-momentum tensor and baryon current. During an initial pre-equilibrium stage based on UrQMD, the four-momenta and baryon numbers carried by secondary particles created within UrQMD are fed continuously, after a short thermalization time, into a (3+1)-dimensional viscous hydrodynamic evolution module including baryon transport. The sensitivity of the initial conditions to model parameters and the effect of baryon diffusion on the hydrodynamic evolution are studied.

    ↳ nucl-thhep-phnucl-exNPA(2019)·52 citations
30. 30*

    Traversable wormholes in four dimensions

    Juan Maldacena🇺🇸 · Alexey Milekhin🇺🇸 · Fedor Popov🇺🇸

    We present a wormhole solution in four dimensions. It is a solution of an Einstein Maxwell theory plus charged massless fermions. The fermions give rise to a negative Casimir-like energy, which makes the wormhole possible. It is a long wormhole that does not lead to causality violations in the ambient space. It can be viewed as a pair of entangled near extremal black holes with an interaction term generated by the exchange of fermion fields. The solution can be embedded in the Standard Model by making its overall size small compared to the electroweak scale.

    ↳ hep-thgr-qchep-phClass.Quant.Grav.(2023)·210 citations
31. 31*

    Finite-volume spectrum of ${\pi }^{+}{\pi }^{+}$ and ${\pi }^{+}{\pi }^{+}{\pi }^{+}$ systems

    Maxim Mai🇺🇸 · Michael Doring🇺🇸

    The ab-initio understanding of hadronic three-body systems above threshold, such as exotic resonances or the baryon spectrum, requires the mapping of the finite-volume eigenvalue spectrum, produced in lattice QCD calculations, to the infinite volume. We present the first application of such a formalism to a physical system in form of three interacting positively charged pions. The results for the ground state energies agree with the available lattice QCD results by the NPLQCD collaboration at unphysical pion masses. Extrapolations to physical pion masses are performed using input from effective field theory. The excited energy spectrum is predicted. This demonstrates the feasibility to determine three-body amplitudes above threshold from lattice QCD, including resonance properties of axial mesons, exotics, and excited baryons.

    ↳ hep-lathep-phnucl-thPRL(2019)·157 citations
32. 32*

    Blazar Flares as an Origin of High-Energy Cosmic Neutrinos?

    Kohta Murase🇺🇸 · Foteini Oikonomou🇩🇪 · Maria Petropoulou🇺🇸

    We consider implications of high-energy neutrino emission from blazar flares, including the recent event IceCube-170922A and the 2014-2015 neutrino flare that could originate from TXS 0506+056. First, we discuss their contribution to the diffuse neutrino intensity taking into account various observational constraints. Blazars are likely to be subdominant in the diffuse neutrino intensity at sub-PeV energies, and we show that blazar flares like those of TXS 0506+056 could make <1-10 percent of the total neutrino intensity. We also argue that the neutrino output of blazars can be dominated by the flares in the standard leptonic scenario for their gamma-ray emission, and energetic flares may still be detected with a rate of <1 per year. Second, we consider multi-messenger constraints on the source modeling. We show that luminous neutrino flares should be accompanied by luminous broadband cascade emission, emerging also in X-rays and gamma-rays. This implies that not only gamma-ray telescopes like Fermi but also X-ray sky monitors such as Swift and MAXI are critical to test the canonical picture based on the single-zone modeling. We also suggest a two-zone model that can naturally satisfy the X-ray constraints while explaining the flaring neutrinos via either photomeson or hadronuclear processes.

    ↳ astro-ph.HEastro-ph.COastro-ph.GAhep-phApJ(2018)·233 citations
33. 33*

    ${\rm Y}$ suppression in a hadron gas

    L. M. Abreu🇧🇷 · F. S. Navarra🇧🇷 · M. Nielsen🇧🇷

    In this work we study the interactions of bottom mesons which lead to ${\rm Y}$ production and absorption in hot hadronic matter. We use effective Lagrangians to calculate the ${\rm Y}$ production cross section in processes such as ${\bar{B}}^{(\ast )}+B^{(\ast )}\to {\rm Y}+(\pi ,\rho )$ and also the ${\rm Y}$ absorption cross section in the corresponding inverse processes. We update and extend previous calculations by Lin and Ko, introducing anomalous interactions. The obtained cross sections are used as input to solve the rate equation which allows us to follow the time evolution of the ${\rm Y}$ multiplicity. In contrast to previous conjectures, our results suggest that the interactions in the hadron gas phase strongly reduce the ${\rm Y}$ abundance.

    ↳ nucl-thhep-phPRC(2020)·18 citations
34. 34*

    Status of the Chiral Magnetic Effect Search in Relativistic Heavy-Ion Collisions

    Jie Zhao🇺🇸 · Zhoudunming Tu🇺🇸 · Fuqiang Wang🇺🇸

    Quark interactions with topological gluon fields in QCD can yield local $\mathcal{P}$ and $\mathcal{C}\mathcal{P}$ violations which could explain the matter-antimatter asymmetry in our universe. Effects of $\mathcal{P}$ and $\mathcal{C}\mathcal{P}$ violations can result in charge separation under a strong magnetic field, a phenomenon called the chiral magnetic effect (CME). Experimental measurements of the CME-induced charge separation in heavy-ion collisions are dominated by physics backgrounds. Major theoretical and experimental efforts have been devoted to eliminating or reducing those backgrounds. We review the current status of these efforts in the search for the CME in heavy-ion collisions.

    ↳ nucl-exhep-exhep-phnucl-thNucl.Phys.Rev.(2018)·26 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.