Tue·Jan 29, 2019Tuesday·January 29, 2019

1. 01*

   Implication of Higgs Precision Measurement on New Physics

   Ning Chen🇨🇳 · Tao Han🇺🇸 · Shufang Su🇺🇸 · Wei Su🇺🇸 · Yongcheng Wu🇨🇦

   Future precision measurements of the Standard Model (SM) parameters at the proposed Z-factories and Higgs factories may have significant impacts on new physics beyond the Standard Model (BSM). We illustrate this by focusing on the Type-II two Higgs doublet model. A multi-variable global fitting is performed with full one loop contributions to relevant couplings. The Higgs signal strength measurements at proposed Higgs factories can provide strong constraints on new physics and are found to be complementary to the Z-pole measurements.

   hep-ph6 citations
2. 02*

   Inclusive diffraction in future electron-proton and electron-ion colliders

   Nestor Armesto🇪🇸 · Paul R. Newman🇬🇧 · Wojciech Slominski🇵🇱 · Anna M. Stasto🇺🇸

   We analyse the possibilities for the study of inclusive diffraction offered by future electron--proton/nucleus colliders in the TeV regime, the Large Hadron-electron Collider as an upgrade of the HL-LHC and the Future Circular Collider in electron-hadron mode. Compared to $ep$ collisions at HERA, we find an extension of the available kinematic range in $x$ by a factor of order $20$ and of the maximum $Q^2$ by a factor of order $100$ for LHeC, while the FCC version would extend the coverage by a further order of magnitude both in $x$ and $Q^2$. This translates into a range of available momentum fraction of the diffractive exchange with respect to the hadron ($\xi$), down to $10^{-4}-10^{-5}$ for a wide range of the momentum fraction of the parton with respect to the diffractive exchange ($\beta$). Using the same framework and methodology employed in previous studies at HERA, considering only the experimental uncertainties and not those stemming from the functional form of the initial conditions or other ones of theoretical origin, and under very conservative assumptions for the luminosities and systematic errors, we find an improvement in the extraction of diffractive parton densities from fits to reduced cross sections for inclusive coherent diffraction in $ep$ by about an order of magnitude. For $eA$, we also perform the simulations for the Electron Ion Collider. We find that an extraction of the currently unmeasured nuclear diffractive parton densities is possible with similar accuracy to that in $ep$.

   hep-phPRD(2019)·45 citations
3. 03*

   Scotogenic $U(1{)}_{\chi }$ Dirac Neutrinos

   Ernest Ma (UC Riverside)🇺🇸

   The standard model of quarks and leptons is extended to include the gauge symmetry $U(1{)}_{\chi }$ which comes from $SO(10)\to SU(5)\times U(1{)}_{\chi }$. The radiative generation of Dirac neutrino masses through dark matter is discussed in two examples. One allows for light Dirac fermion dark matter. The other allows for self-interacting scalar dark matter with a light scalar mediator which decays only to two neutrinos.

   hep-phPLB(2019)·41 citations
4. 04*

   Predictions for energy correlators probing substructure of groomed heavy quark jets

   Christopher Lee🇺🇸 · Prashant Shrivastava🇺🇸 · Varun Vaidya🇺🇸

   We develop an effective field theory (EFT) framework to perform an analytic calculation for energy correlator observables computed on groomed heavy-quark jets. A soft-drop grooming algorithm is applied to a jet initiated by a massive quark to minimize soft contamination effects such as pile-up and multi-parton interactions. We specifically consider the two-particle energy correlator as an initial application of this EFT framework to compute heavy quark jet substructure. We find that there are different regimes for the event shapes, depending on the size of the measured correlator observable, that require the use of different EFT formulations, in which the quark mass and grooming parameters may be relevant or not. We use the EFT to resum large logarithms in the energy correlator observable in terms of the momentum of a reconstructed heavy hadron to NLL${}^{\prime }$ accuracy and subsequently match it to a full QCD $\mathcal{O}({\alpha }_s)$ cross section, which we also compute. We compare our predictions to simulations in PYTHIA for $e^{+}{e}^{-}$ collisions. We find a good agreement with partonic simulations, as well as hadronic ones with an appropriate shape function used to describe nonperturbative effects and the heavy quark hadron decay turned off. We also predict the scaling behavior for the leading nonperturbative power correction due to hadronization. Consequently, we can give a prediction for the energy correlator distribution at the level of the reconstructed heavy hadron. This work provides a general framework for the analysis of heavy quark jet substructure observables.

   hep-phnucl-thJHEP(2019)·43 citations
5. 05*

   The Excited Charmonium Production in $e^{+}{e}^{-}$ Annihilation

   Han-Jie Tao🇨🇳 · Yan-Jun Sun🇨🇳 · Song-Pei Guo🇨🇳 · Wei Hong🇨🇳 · Qi Huang🇨🇳

   We calculate the form factor and cross section of the excited charmonium production process $e^{+}+e^{-}\to \psi \left(2S\right)+{\eta }_c$ by light-cone sum rules. In our method, the form factor depends on the distribution amplitude of ${\eta }_c$ meson. Experimentally, the energy scale of $e^{+}+e^{-}\to \psi \left(2S\right)+{\eta }_c$ process is much larger than the initial energy scale of ${\eta }_c$ meson in our BHL model. Therefore, we further consider the evolution of the distribution amplitude with the energy scale, and select the distribution amplitude as our input parameter when the final effective energy scale is $\mu =5.00GeV$. This treatment means that we have chosen the relativistic distribution amplitude. The results show that the relativistic effect contributes greatly to the form factor and cross section. Our results are consistent with Belle experimental data.

   hep-ph2 citations
6. 06*

   Heavy quark spin multiplet structure of $P_c$-like pentaquark as P-wave hadronic molecular state

   Yuki Shimizu🇯🇵 · Yasuhiro Yamaguchi🇯🇵 · Masayasu Harada🇯🇵

   We study the heavy quark spin (HQS) multiplet structure of P-wave $Q\bar{Q}qqq$-type pentaquarks treated as molecules of a heavy meson and a heavy baryon. We define the light-cloud spin (LCS) basis decomposing the meson-baryon spin wavefunction into the LCS and HQS parts. Introducing the LCS basis, we find HQS multiplets classified by the LCS; five HQS singlets, two HQS doublets, and three HQS triplets. We construct the one-pion exchange potential respecting the heavy quark spin and chiral symmetries to demonstrate which HQS multiplets are realized as a bound state. By solving the coupled channel Schrödinger equations, we study the heavy meson-baryon systems with $I=1/2$ and $J^P=(1/2^{+},3/2^{+},5/2^{+},7/2^{+})$. The bound states which have same LCS structure are degenerate at the heavy quark limit, and the degeneracy is resolved for finite mass. This HQS multiplet structure will be measured in the future experiments.

   hep-phnucl-thPTEP(2019)·12 citations
7. 07*

   Bi$\mathbf{\nu }$o phenomenology at the LHC

   Patrick J. Fox🇺🇸 · Julia Gehrlein🇪🇸 · Seyda Ipek🇺🇸

   We study the LHC constraints on an $R$-symmetric SUSY model, where the neutrino masses are generated through higher dimensional operators involving the pseudo-Dirac bino, named bi$\nu$o. We consider a particle spectrum where the squarks are heavier than the lightest neutralino, which is a pure bi$\nu$o. The bi$\nu$o is produced through squark decays and it subsequently decays to a combination of jets and leptons, with or without missing energy, via its mixing with the Standard Model neutrinos. We recast the most recent LHC searches for jets+missing energy with $\sqrt{s}=13$TeV and $\mathcal{L}=36{\mathrm{fb}}^{-1}$ of data to determine the constraints on the squark and bi$\nu$o masses in this model. We find that squarks as light as 350~GeV are allowed if the bi$\nu$o is lighter than 150~GeV and squarks heavier than 950~GeV are allowed for any bi$\nu$o mass. We also present forecasts for the LHC with $\sqrt{s}=13$~TeV and $\mathcal{L}=300{\mathrm{fb}}^{-1}$ and show that squarks up to 1150~GeV can be probed.

   hep-phJHEP(2019)·5 citations
8. 08*

   Energy loss of heavy and light quarks in holographic magnetized background

   Zhou-Run Zhu🇨🇳 · Sheng-Qin Feng🇨🇳 · Ya-Fei Shi🇨🇳 · Yang Zhong🇨🇳

   We systematically study holographic effects on the magnetic field dependence of the drag force, diffusion coefficient, jet quenching parameter of heavy quarks and the shooting string energy loss of light quarks in the RHIC and LHC energy regions by using the AdS/CFT correspondence in this paper. This study is motivated by the phenomena of strong magnetic field and jet quenching, which have been found in relativistic heavy ion collisions. The probe's direction of motion is perpendicular and parallel to the direction of magnetic field $B$. The effects of magnetic field on energy loss when moving perpendicular to the magnetic field direction are larger than moving parallel to the magnetic field direction, which implies that the magnetic field tends to suppress more quarks and jets when moving in the transverse direction than in the parallel direction. It is found that the diffusion coefficient decreases with the magnetic field in the transverse direction, but increases with the magnetic field in the parallel direction, which indicates that the quark may diffuse farther when moving parallel to the magnetic field direction. We also find that the magnetic field will enhance the energy loss of the light quarks when moving in the transverse direction than in the parallel direction.

   hep-phPRD(2019)·31 citations
9. 09*

   Updated analysis of recent results on electron and positron elastic scattering on proton

   V. V. Bytev🇷🇺 · E. Tomasi-Gustafsson🇫🇷

   We discuss recent experimental results concerning the cross section ratio of positron over electron elastic scattering on protons, and compare with the predictions of a pre-existent calculation. The deviation from unity of this ratio, $i.e.$, a charge asymmetry different from zero, is the signature of contributions beyond the Born approximation. After reviewing the published results, we compare the elastic data to a calculation which includes the diagram corresponding to two-photon exchange. It turns out that all the data on the cross section ratio, in the limit of their precision, do not show evidence of enhanced two-photon contribution beyond the expected percent level. Our results confirm that experimental evidence for a large contribution of two-photon exchange is not yet found.

   hep-phnucl-thPRC(2019)·10 citations
10. 10*

    Direct reduction of multiloop multiscale scattering amplitudes

    Yefan Wang🇨🇳 · Zhao Li🇨🇳 · Najam ul Basat🇨🇳

    We propose an alternative approach based on series representation to directly reduce multi-loop multi-scale scattering amplitude into set of freely chosen master integrals. And this approach avoid complicated calculations of inverse matrix and dimension shift for tensor reduction calculation. During this procedure we further utilize the Feynman parameterization to calculate the coefficients of series representation and obtain the form factors. Conventional methodologies are used only for scalar vacuum bubble integrals to finalize the result in series representation form. Finally, we elaborate our approach by presenting the reduction of a typical two-loop amplitude for W boson production.

    hep-phPRD(2020)·27 citations
11. 11*

    Improving the measurement of the Higgs boson-gluon coupling using convolutional neural networks at $e^{+}{e}^{-}$ colliders

    Gexing Li🇨🇳 · Zhao Li🇨🇳 · Yan Wang🇨🇳 · Yefan Wang🇨🇳

    In this paper we propose to use convolutional neural networks (CNNs) to improve the precision measurement of the Higgs boson-gluon effective coupling at lepton colliders. The CNN is employed to recognize the Higgs boson and a $Z$ boson associated production process, with the Higgs boson decaying to a gluon pair and the $Z$ boson decaying to a lepton pair at the center-of-mass energy 250 GeV and integrated luminosity 5 ab${}^{-1}$. By using CNNs, the uncertainty of the effective coupling measurement can be decreased from $1.94\%$ to about $1.28\%$ using the PYTHIA data and from $1.82\%$ to about $1.22\%$ using the HERWIG data in the Monte Carlo simulation. Moreover, the performance of CNNs using different final state constituents shows that the energy distributions of the leading and subleading jets constituents play a major role in the identification and the optimal uncertainty of effective coupling using CNNs is reduced by about $35\%$ compared to that using conventional method.

    hep-phPRD(2019)·8 citations
12. 12*

    Functional reduction of Feynman integrals

    Tarasov O.V🇷🇺

    A method for reducing Feynman integrals, depending on several kinematic variables and masses, to a combination of integrals with fewer variables is proposed. The method is based on iterative application of functional equations proposed by the author. The reduction of the one-loop scalar triangle and box integrals with massless internal propagators to simpler integrals is described in detail. The triangle integral depending on three variables is represented as a sum over three integrals depending on two variables. By solving the dimensional recurrence relations for these integrals, an analytic expression in terms of the ${}_2{F}_1$ Gauss hypergeometric function and the logarithmic function was derived. By using the functional equations, the one-loop box integral with massless internal propagators, which depends on six kinematic variables, was expressed as a sum of 12 terms. These terms are proportional to the same integral depending only on three variables different for each term. For this integral with three variables, an analytic result in terms of the $F_1$ Appell and ${}_2{F}_1$ Gauss hypergeometric functions was derived by solving the recurrence relation with respect to the spacetime dimension $d$. The reduction equations for the box integral with some kinematic variables equal to zero are considered.

    hep-phJHEP(2019)·9 citations
13. 13*

    Chiral Lagrangians for mesons with a single heavy quark

    Shao-Zhou Jiang🇨🇳 · Yan-Rui Liu🇨🇳 · Qin-He Yang🇨🇳

    We construct the relativistic chiral Lagrangians for heavy-light mesons $(Q\bar{q})$ to the $\mathcal{O}(p^4)$ order. From $\mathcal{O}(p^2)$ to $\mathcal{O}(p^4)$, there are 17, 67, and 404 independent terms in the flavor $SU(2)$ case and 20, 84, and 655 independent terms in the flavor $SU(3)$ case. The Lagrangians in the heavy quark limit are also obtained. From $\mathcal{O}(p^2)$ to $\mathcal{O}(p^4)$, there are 7, 25, and 136 independent terms in the flavor $SU(2)$ case and 8, 33, and 212 independent terms in the flavor $SU(3)$ case. The relations between low-energy constants based on the heavy quark symmetry are also given up to the $\mathcal{O}(p^3)$ order.

    hep-phhep-latnucl-thPRD(2019)·18 citations
14. 14*

    Phenomenology of an extended IDM with loop-generated fermion mass hierarchies

    A. E. Cárcamo Hernández🇨🇱 · Sergey Kovalenko🇨🇱 · Roman Pasechnik🇸🇪 · Ivan Schmidt🇨🇱

    We perform a comprehensive analysis of the most distinctive and important phenomenological implications of the recently proposed mechanism of sequential loop generation of strong hierarchies in the Standard Model (SM) fermion mass spectra. This mechanism is consistently realized at the level of renormalizable interactions in an extended variant of the Inert Higgs Doublet model, possessing the additional $Z_2^{(1)}\times Z_2^{(2)}$ discrete and $U_{1X}$ gauge family symmetries, while the matter sectors of the SM are extended by means of $S{U}_{2L}$-singlet scalars, heavy vector-like leptons and quarks, as well as right-handed neutrinos. We thoroughly analyze the most stringent constraints on the model parameter space, coming from the $Z^{\prime }$ collider searches, related to the anomaly in lepton universality, and the muon anomalous magnetic moment, as well as provide benchmark points for further tests of the model and discuss possible "standard candle" signatures relevant for future explorations.

    hep-phEPJC(2019)·21 citations
15. 15*

    Elastic proton-proton scattering at LHC energies in holographic QCD

    Wei Xie🇨🇳 · Akira Watanabe🇨🇳 · Mei Huang🇨🇳

    The cross sections of the high energy proton-proton scattering are studied in a holographic QCD model, focusing on the Regge regime. In our model setup, the involved nonperturbative partonic dynamics is described by the Pomeron exchange, which is realized by applying the Reggeized spin-2 particle propagator together with the proton gravitational form factor obtained from the bottom-up AdS/QCD model. Our model includes three adjustable parameters which are to be fitted by experimental data. We show that both the resulting differential and total cross sections are consistent with data, including the ones recently measured at $\sqrt{s}=13$ TeV by the TOTEM collaboration at the LHC. Our results imply that the present framework works well in the considered TeV scale, and further applications to other high energy scattering processes, in which the involved strong interaction can be approximated by the Pomeron exchange, are possible.

    hep-phhep-thnucl-exnucl-thJHEP(2019)·26 citations
16. 16*

    Spin polarization evolution in a boost invariant hydrodynamical background

    Wojciech Florkowski🇵🇱 · Avdhesh Kumar🇵🇱 · Radoslaw Ryblewski🇵🇱 · Rajeev Singh🇵🇱

    Relativistic hydrodynamic equations for particles with spin one-half are used to determine the space-time evolution of the spin polarization in a boost-invariant and transversely homogeneous background. The hydrodynamic approach uses the forms of the energy-momentum and spin tensors based on de Groot, van Leeuwen, and van Weert formalism. Our calculations illustrate how the formalism of hydrodynamics with spin can be used to determine physical observables related to the spin polarization and how the latter can be compared with the experimental data.

    hep-phnucl-thPRC(2019)·110 citations
17. 17*

    Pseudo Nambu-Goldstone Dark Matter: Examples of Vanishing Direct Detection Cross Section

    Dimitrios Karamitros🇵🇱

    We consider cases where the dark matter-nucleon interaction is naturally suppressed. We explicitly show that by extending the standard model scalar sector by a number of singlets, can lead to a vanishing direct detection cross section, if some softly broken symmetries are imposed in the dark sector. In particular, it is shown that if said symmetries are $SU(2)$ ($SU(N)$) and $U(1)\times S_N$, then the resulting pseudo-Nambu-Goldstone bosons can constitute the dark matter of the Universe, while naturally explaining the missing signal in nuclear recoil experiments.

    hep-phPRD(2019)·41 citations
18. 18*

    Heavy hybrids and tetraquarks in effective field theory

    Jaume Tarrús Castellà🇪🇸

    We report on an effective field theory (EFT) description of exotic quarkonia as bound states on the spectrum of hybrid and tetraquark static energies. We provide expressions for hybrid and tetraquark static energies in terms of Wilson loops. The former have been computed in quenched lattice calculations but the latter are yet unavailable. From the few simulations with dynamical light-quarks we argue that the overall picture from hybrid static energies does not change but additional states, such as heavy meson pairs, need to be considered for a full description. In this EFT framework for quarkonium hybrids, we report on recent results for mixing with standard quarkonium, spin-dependent contributions, and semi-inclusive decays.

    hep-phEPJ Web Conf.(2019)·7 citations
19. 19*

    Phenomenological NLO analysis of eta(c) production at the LHC in the collider and fixed-target modes

    Yu Feng🇨🇳 · Jibo He🇨🇳 · Jean-Philippe Lansberg🇫🇷 · Hua-Sheng Shao🇫🇷 · Andrii Usachov🇫🇷 · Hong-Fei Zhang🇨🇳

    In view of the good agreement between the LHCb prompt-eta(c) data at sqrt(s)=7 and 8 TeV and the NLO colour-singlet model predictions --i.e. the leading v^2 NRQCD contribution--, we provide predictions in the LHCb acceptance for the forthcoming 13 TeV analysis bearing on data taken during the LHC Run2. We also provide predictions for sqrt(s)=115 GeV for proton-hydrogen collisions in the fixed-target mode which could be studied during the LHC Run3. Our predictions are complemented by a full theoretical uncertainty analysis. In addition to cross section predictions, we elaborate on the uncertainties on the p bar-p branching ratio --necessary for data-theory comparison-- and discuss other usable branching fractions for future studies.

    hep-phhep-exnucl-exnucl-thNPB(2019)·28 citations
20. 20*

    Universal four-dimensional representation of $H\to \gamma \gamma$ at two loops through the Loop-Tree Duality

    Felix Driencourt-Mangin🇪🇸 · German Rodrigo🇪🇸 · German F. R. Sborlini🇪🇸 · William J. Torres Bobadilla🇪🇸

    We extend useful properties of the $H\to \gamma \gamma$ unintegrated dual amplitudes from one- to two-loop level, using the Loop-Tree Duality formalism. In particular, we show that the universality of the functional form -- regardless of the nature of the internal particle -- still holds at this order. We also present an algorithmic way to renormalise two-loop amplitudes, by locally cancelling the ultraviolet singularities at integrand level, thus allowing a full four-dimensional numerical implementation of the method. Our results are compared with analytic expressions already available in the literature, finding a perfect numerical agreement. The success of this computation plays a crucial role for the development of a fully local four-dimensional framework to compute physical observables at Next-to-Next-to Leading order and beyond.

    hep-phhep-thJHEP(2019)·65 citations
21. 21*

    Line shape and $D^{(\ast )}{\bar{D}}^{(\ast )}$ probabilities of $\psi (3770)$ from the $e^{+}{e}^{-}\to D\bar{D}$ reaction

    Q. X. Yu🇨🇳 · W. H. Liang🇨🇳 · M. Bayar🇹🇷 · E. Oset🇪🇸

    We have performed a calculation of the $D\bar{D}$, $D{\bar{D}}^{\ast }$, $D^{\ast }\bar{D}$, $D^{\ast }{\bar{D}}^{\ast }$ components in the wave function of the $\psi (3770)$. For this we make use of the ${}^3{P}_0$ model to find the coupling of $\psi (3770)$ to these components, that with an elaborate angular momentum algebra can be obtained with only one parameter. Then we use data for the $e^{+}{e}^{-}\to D\bar{D}$ reaction, from where we determine a form factor needed in the theoretical frame work, as well as other parameters needed to evaluate the meson-meson selfenergy of the $\psi (3770)$. Once this is done we determine the $Z$ probability to still have a vector core and the probability to have the different meson components. We find $Z$ about $80\sim 85\%$, and the individual meson-meson components are rather small, providing new empirical information to support the largely $q\bar{q}$ component of vector mesons, and the $\psi (3770)$ in particular.

    hep-phPRD(2019)·5 citations
22. 22*

    Charmonium Excitation functions in $\bar{p}$A Collisions

    Gy. Wolf🇭🇺 · G. Balassa🇭🇺 · P. Kovacs🇭🇺 · M. Zetenyi🇭🇺 · S.H. Lee🇰🇷

    We study the excitation function of the low-lying charmonium state: $\Psi$(3686) in $\bar{p}$ Au collisions taking into account their in-medium propagation. The time evolution of the spectral functions of the charmonium state is studied with a BUU type transport model. We calculated the excitation function of $\Psi$(3686) production and show that it is strongly effected by the medium. The energy regime will be available for the PANDA experiment.

    hep-phnucl-thActa Phys.Polon.Supp.(2018)·4 citations
23. 23*

    Soft anomalous dimensions for single-top production at three loops

    Nikolaos Kidonakis🇺🇸

    I present results for soft anomalous dimensions in single top-quark production processes through three loops. I first discuss the cusp anomalous dimension with one massive and one massless line at three loops. I then calculate the three-loop soft anomalous dimension for $tW$ production and for related processes with new physics such as $tZ$, $t\gamma$, and $t{H}^{-}$ production. This is followed by results at two and three loops for the soft anomalous dimension matrix in $s$-channel single-top production and, finally, in $t$-channel single-top production. These new results are needed for soft-gluon resummation at N${}^3$LL accuracy and for calculations of soft-gluon corrections at N${}^3$LO.

    hep-phPRD(2019)·35 citations
24. 24*

    Detector-size Upper Bounds on Dark Hadron Lifetime from Cosmology

    Lingfeng Li🇨🇳 · Yuhsin Tsai🇺🇸

    We show that in a confining hidden valley model where the lightest hidden particles are dark hadrons that have mass splittings larger than $\mathcal{O}(0.1)$ GeV, if the lightest dark hadron is either stable or decays into Standard Model (SM) hadrons/charged leptons during the big-bang nucleosynthesis (BBN), at least one of the heavier dark hadrons needs to decay into SM particles within $\mathcal{O}(10)$ nanosec. Once being produced at collider experiments, this heavier dark hadron is likely to decay within $\mathcal{O}(1)$ meter distance, which strengthens the motivation of searching for long-lived particles with sub-meter scale decay lengths at colliders. To illustrate the idea, we study the lifetime constraint in scenarios where the lightest dark particle is a pseudo-scalar meson, and dark hadrons couple to SM particles either through kinetic mixing between the SM and dark photons or by mixing between the SM and dark Higgs. We study the annihilation and decay of dark hadrons in a thermal bath and calculate upper bounds on the lightest vector meson (scalar hadron) lifetime in the kinetic mixing (Higgs portal) scenario. We discuss the application of these lifetime constraints in long-lived particle searches that use the LHCb VELO or the ATLAS/CMS inner detectors.

    hep-phJHEP(2019)·16 citations
25. 25*

    Sleptons without Hadrons

    Benjamin Fuks🇫🇷 · Karl Nordström🇳🇱 · Richard Ruiz🇧🇪 · Sophie L. Williamson🇫🇷

    Multilepton searches for electroweakino and slepton pair production at hadron colliders remain some of the best means to test weak-scale supersymmetry. Searches at the CERN Large Hadron Collider, however, are limited by large diboson and top quark pair backgrounds, despite the application of traditional, central jet vetoes. In this context, we report the impact of introducing dynamic jet vetoes in searches for colorless superpartners. As a representative scenario, we consider the Drell-Yan production of a pair of right-handed smuons decaying into a dimuon system accompanied with missing transverse energy. As an exploratory step, we consider several global and local measures of the leptonic and hadronic activity to construct the veto. In most all cases, we find that employing a dynamic jet veto improves the sensitivity, independently of the integrated luminosity. The inclusion of non-perturbative multiple particle interactions and next-to-leading order jet merging does not alter this picture. Directions for further improvements are discussed.

    hep-phhep-exPRD(2019)·14 citations
26. 26*

    Simple Sinflaton-less $\alpha$-attractors

    Renata Kallosh🇺🇸 · Yusuke Yamada🇺🇸

    We construct the simplest inflationary $\alpha$-attractor models in supergravity: it has only one scalar, the inflaton. There is no sinflaton since the inflaton belongs to an orthogonal nilpotent superfield where the sinflaton depends on fermion bilinears. When the local supersymmetry is gauge-fixed, these models have only one single real scalar (the inflaton), a graviton and a massive gravitino. The sinflaton, sgoldstino and inflatino are all absent from the physical spectrum in the unitary gauge. The orthogonality condition leads to the simplest Kähler potential for the inflaton, while preserving the Poincaré disk geometry of $\alpha$-attractors. The models are particularly simple in the framework of the $\overline{D3}$ induced geometric inflation.

    ↳ hep-thastro-ph.COgr-qchep-phJHEP(2019)·5 citations
27. 27*

    Theoretical Review of Charmonium Production with Different $p_T$ in the Hot Medium

    Baoyi Chen🇨🇳 · Carsten Greiner🇩🇪

    Charmonia with different transverse momentum $p_T$ usually comes from different mechanisms in the relativistic heavy ion collisions. This work tries to review the theoretical studies on quarkonium evolutions in the deconfined medium produced in p-Pb and Pb-Pb collisions. The charmonia with high $p_T$ are mainly from the initial hadronic collisions, and therefore sensitive to the initial energy density of the bulk medium. For those charmonia within $0.1<p_T<5$ GeV/c at the energies of Large Hadron Collisions (LHC), They are mainly produced by the recombination of charm and anti-charm quarks in the medium. In the extremely low $p_T\sim 1/R_A$ ($R_A$ is the nuclear radius), additional contribution from the coherent interactions between electromagnetic fields generated by one nucleus and the target nucleus plays a non-negligible role in the $J/\psi$ production even in semi-central Pb-Pb collisions.

    ↳ nucl-thhep-phEPJ Web Conf.(2019)·1 citation
28. 28*

    Reducible contributions to quantum electrodynamics in external fields

    Naser Ahmadiniaz🇩🇪 · James P. Edwards🇲🇽 · Anton Ilderton🇬🇧

    We consider one-particle reducible (1PR) contributions to QED and scalar QED processes in external fields, at one-loop and two-loop order. We investigate three cases in detail: constant crossed fields, constant magnetic fields, and plane waves. We find that 1PR tadpole contributions in plane waves and constant crossed fields are non-zero, but contribute only divergences to be renormalised away. In constant magnetic fields, on the other hand, tadpole contributions give physical corrections to processes at one-loop and beyond. Our calculations are exact in the external fields and we give strong and weak field expansions in the magnetic case.

    ↳ hep-thhep-phJHEP(2019)·24 citations
29. 29*

    Forward and backward comparative study of jet properties in pp collisions at \sqrt{s}=7 TeV

    Yu-Liang Yan🇨🇳 · Ayut Limphirat🇹🇭 · Dai-Mei Zhou🇨🇳 · Pornrad Srisawad🇹🇭 · Yupeng Yan🇹🇭 · Chunbin Yang🇨🇳 · Xu Cai🇨🇳 · Ben-Hao Sa🇨🇳

    We propose a forward method, based on the PYTHIA6.4, to study theoretically the jet properties in the ultra-relativistic pp collisions. In the forward method, the partonic initial states are first generated with PYTHIA6.4 and then hadronized in the Lund srting fragmentation regime, and finally hadronic jets are constructed from the created hadrons. Jet properties calculated in the forward method for pp collisions at \sqrt{s}=7 TeV are comparable with the corresponding ones calculated with usual anti-k_t algorithm (backward method) in the PYTHIA6.4. The comparison between the results in the backward and forward methods may bring benefit to the understanding of the partonic origin of jets in the backward method.

    ↳ nucl-thhep-phCPC(2020)·0 citations
30. 30*

    Impact of different extended components of mean field models on transport coefficients of quark matter and their causal aspects

    Chowdhury Aminul Islam🇮🇳 · Jayanta Dey🇮🇳 · Sabyasachi Ghosh🇮🇳

    Role of different extensions of Nambu\textendash Jona-Lasinio (NJL) model like addition of vector interaction, Polyakov loop extended version (PNJL) and the entangled PNJL (EPNJL) models on transport coefficients like shear viscosity, bulk viscosity, electrical conductivity and thermal conductivity are critically analyzed. We have considered the standard expressions of transport coefficients, obtained in relaxation time approximation of kinetic theory. Influence of temperature dependent order parameters on temperature profile of transport coefficients are analyzed. Causal aspect of massless case to these different extended components of mean field models are also picturized, where an approximated lower and upper bound are drawn for shear relaxation time.

    ↳ nucl-thhep-phPRC(2021)·15 citations
31. 31*

    Charmed nuclei within a microscopic many-body approach

    I. Vidana🇮🇹 · A. Ramos🇪🇸 · C. E. Jimenez-Tejero🇪🇸

    Single-particle energies of the ${\Lambda }_c$ chamed baryon are obtained in several nuclei from the relevant self-energy constructed within the framework of a perturbative many-body approach. Results are presented for a charmed baryon-nucleon ($Y_{c}N$) potential based on a SU(4) extension of the meson-exchange hyperon-nucleon potential $\tilde{A}$ of the Jülich group. Three different models (A, B and C) of this interaction, that differ only on the values of the couplings of the scalar $\sigma$ meson with the charmed baryons, are considered. Phase shifts, scattering lengths and effective ranges are computed for the three models and compared with those predicted by the $Y_{c}N$ interaction derived in Eur. Phys. A {\bf 54}, 199 (2018) from the extrapolation to the physical pion mass of recent results of the HAL QCD Collaboration. Qualitative agreement is found for two of the models (B and C) considered. Our results for ${\Lambda }_c$-nuclei are compatible with those obtained by other authors based on different models and methods. We find a small spin-orbit splitting of the $p-,d-$ and $f-$wave states as in the case of single $\Lambda$-hypernuclei. The level spacing of ${\Lambda }_c$ single-particle energies is found to be smaller than that of the corresponding one for hypernuclei. The role of the Coulomb potential and the effect of the coupling of the ${\Lambda }_{c}N$ and ${\Sigma }_{c}N$ channels on the single-particle properties of ${\Lambda }_c-$nuclei are also analyzed. Our results show that, despite the Coulomb repulsion between the ${\Lambda }_c$ and the protons, even the less attractive one of our $Y_{c}N$ models (model C) is able to bind the ${\Lambda }_c$ in all the nuclei considered. The effect of the ${\Lambda }_{c}N-{\Sigma }_{c}N$ coupling is found to be almost negligible due to the large mass difference of the ${\Lambda }_c$ and ${\Sigma }_c$ baryons.

    ↳ nucl-thhep-phnucl-exPRC(2019)·16 citations
32. 32*

    Light Bending in Models with a Generic Scalar Field

    Dongjin Chway🇰🇷

    We study the deflection and time delay of light by the Sun in general scalar extensions of the Standard Model which may violate the equivalence principle. Despite the presence of the interaction $\varphi FF$ or $\varphi F\tilde{F}$ between the scalar field and photon, we show that the bending and time delay of light are the same as in Einstein's general relativity. The bending angle is obtained using geometrical optics and compared with the angle obtained using another method based on scattering amplitude. It is pointed out that the method based on scattering amplitude can lead to wrong conclusions about potential energy and light polarization. Also, we obtain a constraint on the generic scalar particle from the parametrized post-Newtonian parameter $\gamma$, noting that planet motions are affected by the scalar field as in scalar-tensor theories with some modifications to the scalar field's couplings to the Sun and planets.

    ↳ gr-qchep-ph5 citations
33. 33*

    Dynamical Generation of Elementary Fermion Mass: First Lattice Evidence

    Stefano Capitani🇩🇪 · Petros Dimopoulos🇮🇹 · Roberto Frezzotti🇮🇹 · Marco Garofalo🇮🇹 · Bartosz Kostrzewa🇩🇪 · Ferenc Pittler🇩🇪 · Giancarlo Rossi🇮🇹 · Carsten Urbach🇩🇪

    Using lattice simulations we demonstrate from first principles the existence of a non-perturbative mechanism for elementary particle mass generation in models with gauge fields, fermions and scalars, if an exact invariance forbids power divergent fermion masses and fermionic chiral symmetries broken at UV scale are maximally restored. We show that in the Nambu-Goldstone phase a fermion mass term, unrelated to the Yukawa operator, is dynamically generated. In models with electro-weak interactions weak boson masses are also generated opening new scenarios for beyond the Standard Model physics.

    ↳ hep-thhep-lathep-phPRL(2019)·13 citations
34. 34*

    Confronting gravitational-wave observations with modern nuclear physics constraints

    I. Tews🇺🇸 · J. Margueron🇫🇷 · S. Reddy🇺🇸

    Multi-messenger observations of neutron star (NS) mergers have the potential to revolutionize nuclear astrophysics. They will improve our understanding of nucleosynthesis, provide insights about the equation of state (EOS) of strongly-interacting matter at high densities, and enable tests of the theory of gravity and of dark matter. Here, we focus on the EOS, where both gravitational waves (GWs) from neutron-star mergers and X-ray observations from space-based detectors such as NICER will provide more stringent constraints on the structure of neutron stars. Furthermore, recent advances in nuclear theory have enabled reliable calculations of the EOS at low densities using effective field theory based Hamiltonians and advanced techniques to solve the quantum many-body problem. In this paper, we address how the first observation of GWs from GW170817 can be combined with modern calculations of the EOS to extract useful insights about the EOS of matter encountered inside neutron stars. We analyze the impact of various uncertainties, the role of phase transitions in the NS core, and discuss how future observations will improve our understanding of dense matter.

    ↳ nucl-thastro-ph.HEhep-phEPJA(2019)·113 citations
35. 35*

    First study of reionization in tilted flat and untilted non-flat dynamical dark energy inflation models

    Sourav Mitra🇮🇳 · Chan-Gyung Park🇰🇷 · Tirthankar Roy Choudhury🇮🇳 · Bharat Ratra🇺🇸

    We examine the effects of dark energy dynamics and spatial curvature on cosmic reionization by studying reionization in tilted spatially-flat and untilted non-flat XCDM and $\varphi$CDM dynamical dark energy inflation models that best fit the Planck 2015 cosmic microwave background (CMB) anisotropy and a large compilation of non-CMB data. We carry out a detailed statistical study, based on a principal component analysis and a Markov chain Monte Carlo analysis of a compilation of lower-redshift reionization data, to estimate the uncertainties in the cosmological model reionization histories. We find that, irrespective of the nature of dark energy, there are significant differences between the reionization histories of the spatially-flat and non-flat models. Although both the flat and non-flat models can accurately match the low-redshift ($z\lesssim 6$) reionization observations, there is a clear discrepancy between high-redshift ($z>7$) Lyman-$\alpha$ emitter data and the predictions from non-flat models. This is solely due to the fact that the non-flat models have a significantly larger electron scattering optical depth, ${\tau }_{\mathrm{el}}$, compared to the flat models, which requires an extended and much earlier reionization scenario supported by more high-redshift ionizing sources in the non-flat models. Non-flat models also require strong redshift evolution in the photon escape fraction, that can become unrealistically high ($\gtrsim 1$) at some redshifts. However, ${\tau }_{\mathrm{el}}$ is about 0.9-$\sigma$ lower in the tilted flat $\Lambda$CDM model when the new Planck 2018 data are used and this reduction will partially alleviate the tension between the non-flat model predictions and the data.

    ↳ astro-ph.COgr-qchep-phhep-thMNRAS(2019)·17 citations
36. 36*

    Dressed states from gauge invariance

    Hayato Hirai🇯🇵 · Sotaro Sugishita🇯🇵

    The dressed state formalism enables us to define the infrared finite $S$-matrix for QED. In the formalism, asymptotic charged states are dressed by clouds of photons. The dressed asymptotic states are originally obtained by solving the dynamics of the asymptotic Hamiltonian in the far past or future region. However, there was an argument that the obtained dressed states are not gauge invariant. We resolve the problem by imposing a correct gauge invariant condition. We show that the dressed states can be obtained just by requiring the gauge invariance of asymptotic states. In other words, Gauss's law naturally leads to proper asymptotic states for the infrared finite $S$-matrix. We also discuss the relation between the dressed state formalism and the asymptotic symmetry for QED.

    ↳ hep-thhep-phJHEP(2019)·33 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.