Thu·Jul 11, 2019Thursday·July 11, 2019

1. 01*

   Top-quark pair hadroproduction in association with a heavy boson at NLO+NNLL including EW corrections

   Alessandro Broggio🇮🇹 · Andrea Ferroglia🇺🇸 · Rikkert Frederix🇸🇪 · Davide Pagani🇩🇪 · Benjamin D. Pecjak🇬🇧 · Ioannis Tsinikos🇩🇪

   This work studies the associated production of a top-quark pair with a $W$, $Z$, or Higgs boson at the LHC. Predictions for the total cross sections as well as for several differential distributions of the massive particles in the final state are provided. These predictions, valid for the LHC operating at $13$ TeV, include without any approximation all the NLO electroweak and QCD contributions of $\mathcal{O}({\alpha }_s^i{\alpha }^{j+1})$ with $i+j=2,3$. In addition, the predictions presented here improve upon the NLO QCD results by adding the effects of soft gluon emission corrections resummed to next-to-next-to-leading logarithmic accuracy. The residual dependence of the predictions on scale and PDF choices is analyzed.

   hep-phJHEP(2019)·144 citations
2. 02*

   Strongly interacting dark sectors in the early Universe and at the LHC through a simplified portal

   Elias Bernreuther🇩🇪 · Felix Kahlhoefer🇩🇪 · Michael Krämer🇩🇪 · Patrick Tunney🇩🇪

   We study the cosmology and LHC phenomenology of a consistent strongly interacting dark sector coupled to Standard Model particles through a generic vector mediator. We lay out the requirements for the model to be cosmologically viable, identify annihilations into dark vector mesons as the dominant dark matter freeze-out process and discuss bounds from direct detection. At the LHC the model predicts dark showers, which can give rise to semi-visible jets or displaced vertices. Existing searches for di-jet resonances and for missing energy mostly probe the parameter regions where prompt decays are expected and constrain our model despite not being optimised for dark showers. We also estimate the sensitivity of dedicated analyses for semi-visible jets and emphasize the complementarity of different search strategies.

   hep-phastro-ph.COJHEP(2020)·96 citations
3. 03*

   Toward an effective theory of quarkonium production in nuclear matter

   Ivan Vitev🇺🇸

   These proceedings are dedicated to Miklos Gyulassy's 70${}^{\mathrm{th}}$ birthday. In his long and distinguished career he has made seminal contributions to many areas of heavy ion theory, including early papers on quarkonium phenomenology in fixed-target heavy ion experiments. Theoretical and experimental studies of the $J/\psi$ and ${\rm Y}$ states have evolved considerably in the past decades, and I describe a recent generalization of non-relativistic Quantum Chromodynamics to include interactions in a generic nuclear medium. NRQCD with Glauber gluons aims to provide a universal microscopic description of the interaction of heavy quarkonia in a range of phases that include cold nuclear matter, dense hadron gas, and quark-gluon plasma. Such effective field theory is an important step toward understanding the common trends in proton-nucleus and nucleus-nucleus data on quarkonium suppression.

   hep-phnucl-thPoS(2020)·1 citation
4. 04*

   Hyperon production in ${\Lambda }_c^{+}\to K^{-}p{\pi }^{+}$ and ${\Lambda }_c^{+}\to K_S^{0}p{\pi }^0$

   Jung Keun Ahn🇰🇷 · Seongbae Yang🇰🇷 · Seung-il Nam🇰🇷

   We investigate $S=-1$ hyperon production from the ${\Lambda }_c^{+}\to K^{-}p{\pi }^{+}$ and ${\Lambda }_c^{+}\to K_S^{0}p{\pi }^0$ decays within the effective Lagrangian approach. We consider the $\Sigma /\Lambda$ ground states, $\Lambda (1520)$, $\Lambda (1670)(J^p=1/2^{-})$, $\Lambda (1890)(J^p=3/2^{+})$; $\Lambda /\Sigma$-pole contributions from the combined resonances between 1800 MeV and 2100 MeV; and $N/\Delta$-pole and $K^{\ast }$-pole contributions, which include the proton, $\Delta (1232)$, and $K(892)$. We calculate the Dalitz plot density $(d^2\Gamma /d{M}_{K^{-}p}d{M}_{K^{-}{\pi }^{+}}$) for the ${\Lambda }_c^{+}\to K^{-}p{\pi }^{+}$ decay. The calculated result is in good agreement with experimental data from the Belle Collaboration. Using the parameters from the fit, we present the Dalitz plot density for the ${\Lambda }_c^{+}\to K_S^{0}p{\pi }^0$ decay. In our calculation, a sharp peak-like structure near 1665 MeV is predicted in the ${\Lambda }_c^{+}\to K^{-}p{\pi }^{+}$ decay because of the interference effects between the $\Lambda (1670)$ resonance and $\eta$-$\Lambda$ loop channels. We also demonstrate that we can access direct information regarding the weak couplings of $\Lambda (1670)$ and $\Sigma (1670)$ from the ${\Lambda }_c^{+}\to K_S^{0}p{\pi }^0$ decay. Finally, a possible interpretation for the 1665 MeV structure beyond our prediction is briefly discussed.

   hep-phhep-exnucl-exnucl-thPRD(2019)·11 citations
5. 05*

   Extra dimension of space-time exposed by anomalies at low energy

   Nguyen Ai Viet🇻🇳

   Recent experimental observations are shown to be quantitatively consistent with an extended concept of space-time having a discrete extra dimension of two points at the distance of 11.8 fm together with a nontrivial metric structure. In such a space-time, fermions appear in pair with their Kaluza-Klein siblings. The usual electromagnetic field is accompanied with a new vector boson $X17$, which receives a mass of $17MeV$ from another Kaluza-Klein partner, a scalar boson $H$ of a mass in the range of $0.5-793keV$ via an abelian Higgs mechanism. At a low energy scale, where nucleons can be treated as structureless in a good approximation, the natural particle model involving nucleons, electron, neutrino and their Kaluza-Klein partners coupled to the electromagnetic field and the massive vector boson $X7$ can lead to new phenomenological consequences, which are verifiable at the currently accessible energy.

   hep-phhep-th2 citations
6. 06*

   Constraining FIMP from the structure formation of the Universe: analytic mapping from $m_{\mathrm{WDM}}$

   Ayuki Kamada🇰🇷 · Keisuke Yanagi🇯🇵

   A feebly interacting massive particle (FIMP), contrasting with a weakly interacting massive particle (WIMP), is an intriguing dark matter (DM) candidate. Light (keV-scale) FIMP DM is of particular interest: its radiative decay leaves a line signal in x-ray spectra; and it is warm dark matter (WDM) and alters the galactic-scale structure formation of the Universe from that with WIMP DM. Once a possible x-ray line is reported (e.g., $3.5\mathrm{keV}$ line and $7\mathrm{keV}$ FIMP DM is inferred), one has to check whether or not this FIMP DM is compatible with the structure formation. Here is an issue: the structure formation constraint on WDM is often reported in terms of the so-called thermal WDM mass $m_{\mathrm{WDM}}$, which cannot be directly applied to FIMP parameters. In this paper, we introduce a benchmark FIMP model that represents well a broad class of FIMP models. A big advantage of this benchmark is that we can derive the analytic formula of the non-thermal phase space distribution of FIMPs produced from freeze-in processes. By further deriving a certain "warmness" quantity, we can analytically map $m_{\mathrm{WDM}}$ to FIMP parameters. Our analytic map indicates that $7\mathrm{keV}$ FIMP DM, without entropy production or a degenerate spectrum, is in tension with the latest Lyman-$\alpha$ forest data. Our analytic map will be very useful for future updates of observational constraints and reports of x-ray lines. It is also very easy to incorporate our analytic formula into a Boltzmann solver so that a linear matter power spectrum is readily accessible. Our benchmark model will facilitate FIMP searches and particle physics model-building.

   hep-phastro-ph.COJCAP(2019)·46 citations
7. 07*

   Analysis of the strong decays of the $P_c(4312)$ as a pentaquark molecular state with QCD sum rules

   Zhi-Gang Wang🇨🇳 · Xu Wang🇨🇳

   In this article, we tentatively assign the $P_c(4312)$ to be the $\bar{D}{\Sigma }_c$ pentaquark molecular state with the spin-parity $J^P={\frac{1}{2}}^{-}$, and discuss the factorizable and non-factorizable contributions in the two-point QCD sum rules for the $\bar{D}{\Sigma }_c$ molecular state in details to prove the reliability of the single pole approximation in the hadronic spectral density. We study its two-body strong decays with the QCD sum rules, special attentions are paid to match the hadron side with the QCD side of the correlation functions to obtain solid duality. We obtain the partial decay widths $\Gamma \left(P_c(4312)\to {\eta }_{c}p\right)=0.255\mathrm{MeV}$ and $\Gamma \left(P_c(4312)\to J/\psi p\right)=9.296_{-9.296}^{+19.542}\mathrm{MeV}$, which are compatible with the experimental value of the total width, and support assigning the $P_c(4312)$ to be the $\bar{D}{\Sigma }_c$ pentaquark molecular state.

   hep-phCPC(2020)·71 citations
8. 08*

   Colliding Pomerons

   V.A.Khoze🇬🇧 · A.D.Martin🇬🇧 · M.G.Ryskin🇬🇧

   We recall the main properties of inclusive particle distributions expected for Pomeron-proton and Pomeron-Pomeron interactions. Due to the small size of the Pomeron we expect larger transverse momenta of secondaries and a smaller probability of Multiple Interactions, that is a narrower multiplicity distribution. We propose to compare the spectra of secondaries produced in the Pomeron and the proton interactions in terms of the Feynman $x_F$ variable. The main difference should be observed for a relatively large $x_F$, that is near the edge of rapidity gaps. Such data offer the opportunity to illuminate the properties of the `soft' or `Regge' Pomeron, which drives the minimum-bias type of events in high energy $pp$ interactions. Besides this, there should be a good opportunity to observe a glueball in the Pomeron fragmentation region.

   hep-phJ.Phys.G(2019)·2 citations
9. 09*

   Annihilation energy and decay time of an ortho-Positronium

   Abdullah Guvendi🇹🇷 · Yusuf Sucu🇹🇷

   We approach to the ortho-positronium (o-Ps) as a relativistic two-body problem in $2+1$ dimensions in which o-Ps is composed of two-oppositely charged particles interacting via an attractive Coulomb force. In addition to separation of center of mass and relative coordinates, mapping the background into the polar space-time gives possibility of construction of possible spin eigen-states of o-Ps. This approach makes the energy spectrum complex in order to describe o-Ps that can decay. From the complex energy expression, we find the annihilation energy, binding energy and the life-time of o-Ps, in S state.

   hep-phquant-ph0 citations
10. 10*

    Two-loop diagrams in non-relativistic QCD with elliptics

    B.A. Kniehl🇩🇪 · A.V. Kotikov🇷🇺 · A.I Onishchenko🇷🇺 · O.L. Veretin🇩🇪

    In this paper we consider two-loop two-, three- and four-point diagrams with elliptic structure in the case of two different masses $m$ and $M$. The latter diagrams generally arise within NRQCD matching procedures and are relevant for parapositronium decay and top pair production at threshold. We present the obtained results in several different representations: series solution with binomial coefficients, integral representation and representation in terms of generalized hypergeometric functions. The results are valid up to $\mathcal{O}(\epsilon )$ terms in $d=4-2\epsilon$ space-time dimensions. In the limit of equal masses $m=M$ the obtained results are written in terms of elliptic constants with explicit series representation.

    hep-phhep-thNPB(2019)·33 citations
11. 11*

    Quintessential inflation with a trap and axionic dark matter

    Konstantinos Dimopoulos🇬🇧 · Mindaugas Karčiauskas🇪🇸 · Charlotte Owen🇬🇧

    We study a new model of quintessential inflation which is inspired by supergravity and string theory. The model features a kinetic pole, which gives rise to the inflationary plateau, and a runaway quintessential tail. We envisage a coupling between the inflaton and the Peccei-Quinn (PQ) field which terminates the roll of the runaway inflaton and traps the latter at an enhanced symmetry point (ESP), thereby breaking the PQ symmetry. The kinetic density of the inflaton is transferred to the newly created thermal bath of the hot big bang due to the decay of PQ particles. The model successfully accounts for the observations of inflation and dark energy without any fine-tuning, while also resolving the strong CP problem of QCD and generating axionic dark matter, without isocurvature perturbations. Trapping the inflaton at the ESP ensures that the model does not suffer from the infamous 5th force problem, which typically plagues quintessence.

    hep-phastro-ph.COgr-qchep-thPRD(2019)·19 citations
12. 12*

    $P_c$ pentaquarks with chiral tensor and quark dynamics

    Yasuhiro Yamaguchi🇯🇵 · Hugo Garcia-Tecocoatzi🇮🇹 · Alessandro Giachino🇮🇹 · Atsushi Hosaka🇯🇵 · Elena Santopinto🇮🇹 · Sachiko Takeuchi🇯🇵 · Makoto Takizawa🇯🇵

    We investigate the hidden-charm pentaquarks as superpositions of ${\Lambda }_c{\bar{D}}^{(\ast )}$ and ${\Sigma }_c^{(\ast )}{\bar{D}}^{(\ast )}$ (isospin $I=1/2$) meson-baryon channels coupled to a $uudc\bar{c}$ compact core by employing an interaction satisfying the heavy quark and chiral symmetries. Our model can consistently explain the masses and decay widths of $P_c^{+}(4312)$, $P_c^{+}(4440)$ and $P_c^{+}(4457)$ with the dominant components of ${\Sigma }_c\bar{D}$ and ${\Sigma }_c{\bar{D}}^{\ast }$ with spin parity assignments $J^P=1/2^{-},3/2^{-}$ and $1/2^{-}$, respectively. We analyze basic properties of the $P_c$'s such as masses and decay widths, and find that the mass ordering is dominantly determined by the quark dynamics while the decay widths by the tensor force of the one-pion exchange.

    hep-phPRD(2020)·107 citations
13. 13*

    Modular $S_3$ symmetric radiative seesaw model

    Hiroshi Okada🇰🇷 · Yuta Orikasa🇨🇿

    We propose a one-loop induced radiative seesaw model applying a modular $S_3$ flavor symmetry, which is known as the minimal non-Abelian discrete group. In this scenario, dark matter (DM) candidate is correlated with neutrinos and lepton flavor violations (LFVs). We show several predictions of mixings and phases satisfying LFVs, observed relic density, and neutrino oscillation data.

    hep-phPRD(2019)·133 citations
14. 14*

    Polarized vector boson scattering in the fully leptonic WZ and ZZ channels at the LHC

    Alessandro Ballestrero🇮🇹 · Ezio Maina🇮🇹 · Giovanni Pelliccioli🇮🇹

    Isolating the scattering of longitudinal weak bosons at the LHC is an important tool to probe the ElectroWeak Symmetry Breaking mechanism. Separating polarizations of $W$ and $Z$ bosons is complicated, because of non resonant contributions and interference effects. Additional care is necessary when considering $Z$ bosons, due to the $\gamma /Z$ mixing in the coupling to charged leptons. We propose a method to define polarized signals in $ZZ$ and $W^{+}Z$ scattering at the LHC, which relies on the separation of weak boson polarizations at the amplitude level in Monte Carlo simulations. After validation in the absence of lepton cuts, we investigate how polarized distributions are affected by a realistic set of kinematic cuts (and neutrino reconstruction, when needed). The total and differential polarized cross sections computed at the amplitude level are well defined, and their sum reproduces the full results, up to non negligible but computable interference effects which should be included in experimental analyses. We show that polarized cross sections computed using the reweighting method are inaccurate, particularly at large energies. We also present two procedures which address the model independent extraction of polarized components from LHC data, using Standard Model angular distribution templates.

    hep-phJHEP(2019)·51 citations
15. 15*

    Towards Ultimate Parton Distributions from p+p and e+p Collisions

    Shaun Bailey🇬🇧

    We present results from a detailed assessment of the ultimate constraining power of LHC data on the PDFs that can be expected from the complete dataset, in particular after the High-Luminosity (HL) phase. To achieve this, HL-LHC pseudo-data for different projections of the experimental uncertainties are generated, and the resulting constraints on the PDF4LHC15 set are quantified by means of the Hessian profiling method. We find that HL-LHC measurements can reduce PDF uncertainties by up to a factor of 2 to 4 in comparison to state-of-the-art fits, leading to few-percent uncertainties for important observables such as the Higgs boson transverse momentum distribution via gluon-fusion. Our results illustrate the significant improvement in the precision of PDF fits achievable from hadron collider data alone. In addition, we apply the same methodology to the final anticipated data sample from the proposed LHeC, and compare these with the HL-LHC projections, demonstrating an encouraging complementarity between the projected HL-LHC and LHeC constraints.

    hep-phPoS(2019)·0 citations
16. 16*

    Thermal Loop Effects on Large-Scale Curvature Perturbation in the Higgs Inflation

    Po-Wen Chang🇺🇸 · Cheng-Wei Chiang🇹🇼 · Kin-Wang Ng🇹🇼

    It is known that the Higgs potential in the Standard Model can drive a successful inflation as long as the Higgs field couples non-minimally to gravity. It is then inevitable to take into account the loop corrections of the Standard Model particles to the Higgs potential in the Higgs inflation. In this paper, we discuss the one-loop corrections at finite temperature to the curvature perturbation generated during the Higgs inflation. We find that the thermal loop effects can suppress the power of the curvature perturbation at large scales, thus resulting in a low quadrupole of the temperature anisotropy in the cosmic microwave background.

    hep-phastro-ph.COgr-qcJHEP(2020)·7 citations
17. 17*

    Deciphering the $z_g$ distribution in ultrarelativistic heavy ion collisions

    Paul Caucal🇫🇷 · Edmond Iancu🇫🇷 · Gregory Soyez🇫🇷

    Within perturbative QCD, we develop a new picture for the parton shower generated by a jet propagating through a dense quark-gluon plasma. This picture combines in a simple, factorised, way multiple medium-induced parton branchings and standard vacuum-like emissions, with the phase-space for the latter constrained by the presence of the medium. We implement this picture as a Monte Carlo generator that we use to study two phenomenologically important observables: the jet nuclear modification factor $R_{AA}$ and the $z_g$ distribution reflecting the jet substructure. In both cases, the outcome of our Monte Carlo simulations is in good agreement with the LHC measurements. We provide basic analytic calculations that help explaining the main features observed in the data. We find that the energy loss by the jet is increasing with the jet transverse momentum, due to a rise in the number of partonic sources via vacuum-like emissions. This is a key element in our description of both $R_{AA}$ and the $z_g$ distribution. For the latter, we identify two main nuclear effects: incoherent jet energy loss and hard medium-induced emissions. As the jet transverse momentum increases, we predict a qualitative change in the ratio between the $z_g$ distributions in PbPb and pp collisions: from increasing at small $z_g$, this ratio becomes essentially flat, or even slightly decreasing.

    hep-phnucl-thJHEP(2019)·115 citations
18. 18*

    Critical behaviour of an effective relativistic mean field model in the presence of magnetic background and boundaries

    L. M. Abreu🇧🇷 · E. S. Nery🇧🇷

    In the present work we investigate the combined influence of magnetic background and boundaries on the thermodynamic properties of effective relativistic mean field models, like the so-called Walecka model. This is done by making use of generalized zeta-function approach and mean-field approximation at effective chemical equilibrium, focusing on the dependence with the size of compactified spatial dimension, the temperature and the magnetic field strength. The findings suggest a rich phase structure in the parameter space. The maintenance of long-range correlations is strongly affected under the change of these parameters, with the symmetric phase being favoured due to both inverse magnetic catalysis effect and the reduction of size of compactified dimension.

    ↳ hep-thhep-phEPJA(2019)·6 citations
19. 19*

    Allowed $\beta$-decay spectrum with numerical electron wave functions

    Dong-Liang Fang🇨🇳

    Using numerical electron wave functions and state-of-the-art nuclear many-body methods, I evaluate the $\beta$-decay spectra for typical decay channels of spherical nuclei. I check errors brought by various approximations used for deriving the analytical shape factors (the so-called Fermi Function) of allowed decay. I estimate the errors brought by different electric charge distributions and give a way of estimation of $\beta$-spectra with available decay data of specific nuclei. I found that the traditional ways of approximating the electron wave functions by Fermi Function could be a very severe source of error for spectra simulation.

    ↳ nucl-thhep-ph3 citations
20. 20*

    Localization of gauge bosons and the Higgs mechanism on topological solitons in higher dimensions

    Minoru Eto🇯🇵 · Masaki Kawaguchi🇯🇵

    We provide complete and self-contained formulas about localization of massless/massive Abelian gauge fields on topological solitons in generic $D$ dimensions via a field dependent gauge kinetic term. The localization takes place when a stabilizer (a scalar field) is condensed in the topological soliton. We show that the localized gauge bosons are massless when the stabilizer is neutral. On the other hand, they become massive for the charged stabilizer as a consequence of interplay between the localization mechanism and the Higgs mechanism. For concreteness, we give two examples in six dimensions. The one is domain wall intersections and the other is an axially symmetric soliton background.

    ↳ hep-thhep-phJHEP(2019)·6 citations
21. 21*

    Response of CsI[Na] to Nuclear Recoils: Impact on Coherent Elastic Neutrino-Nucleus Scattering (CE$\nu$NS)

    J.I. Collar🇺🇸 · A.R.L. Kavner🇺🇸 · C.M. Lewis🇺🇸

    A new measurement of the quenching factor for low-energy nuclear recoils in CsI[Na] is presented. Past measurements are revisited, identifying and correcting several systematic effects. The resulting global data are well-described by a physics-based model for the generation of scintillation by ions in this material, in agreement with phenomenological considerations. The uncertainty in the new model is reduced by a factor of four with respect to an energy-independent quenching factor initially adopted as a compromise by the COHERENT collaboration. A significantly improved agreement with Standard Model predictions for the first measurement of CE$\nu$NS is generated. We emphasize the critical impact of the quenching factor on the search for new physics via CE$\nu$NS experiments.

    ↳ nucl-exhep-exhep-phPRD(2019)·62 citations
22. 22*

    Generalised escape paths for dynamical tunneling in QFT

    Luc Darmé🇵🇱 · Joerg Jaeckel🇩🇪 · Marek Lewicki🇬🇧

    We present a formalism based on the functional Schrödinger equation to analyse time-dependent tunneling in quantum field theory at the semi-classical level. The full problem is reduced step by step to a finite dimensional quantum mechanical setup and solved using the WKB approximation. As an example, we consider tunneling from a homogeneous oscillating initial state in scalar quantum field theory.

    ↳ hep-thastro-ph.COhep-phPRD(2019)·12 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.