Tue·Dec 3, 2019Tuesday·December 3, 2019

1. 01*

   Spin asymmetries in quasielastic charged current neutrino-nucleon scattering

   Krzysztof M. Graczyk🇵🇱 · Beata E. Kowal🇵🇱

   The work concerns the quasielastic charged current neutrino-neutron and antineutrino-proton interactions. Single, double, and triple spin asymmetries are computed and analyzed. The spin asymmetries are sensitive to the axial form factor of the nucleon. In particular, the target-recoil double spin asymmetry and the lepton-target-recoil triple spin asymmetry depend strongly on the axial form factor of the nucleon. Indeed, the sign and shape of these components depend on the axial mass parameter. All the asymmetries, except the lepton polarization, are observables well suited to study the nonstandard interactions described by the second class current contribution.

   hep-phnucl-thPRD(2020)·13 citations
2. 02*

   NNLO QCD+NLO EW with MATRIX+OpenLoops: precise predictions for vector-boson pair production

   Massimiliano Grazzini🇨🇭 · Stefan Kallweit🇮🇹 · Jonas M. Lindert🇬🇧 · Stefano Pozzorini🇨🇭 · Marius Wiesemann🇩🇪

   We present the first combination of NNLO QCD and NLO EW corrections for vector-boson pair production at the LHC. We consider all final states with two, three and four charged leptons, including resonant and non-resonant diagrams, spin correlations and off-shell effects. Detailed predictions are discussed for three representative channels corresponding to $W^{+}{W}^{-}$, $W^{\pm }Z$ and $ZZ$ production. Both QCD and EW corrections are very significant, and the details of their combination can play a crucial role to achieve the level of precision demanded by experimental analyses. In this context we point out nontrivial issues that arise at large transverse momenta, where the EW corrections are strongly enhanced by Sudakov logarithms and the QCD corrections can feature so-called giant K-factors. Our calculations have been carried out in the MATRIX+OpenLoops framework and can be extended to the production of an arbitrary colour singlet in hadronic collisions, provided that the required two-loop QCD amplitudes are available. Combined NNLO QCD and NLO EW predictions for the full set of massive diboson processes will be made publicly available in the next release of MATRIX and will be instrumental in advancing precision diboson studies and new-physics searches at the LHC and future hadron colliders.

   hep-phhep-exJHEP(2020)·143 citations
3. 03*

   A heavy neutral gauge boson near the Z boson mass pole via third generation fermions at the LHC

   Mohammad Abdullah🇺🇸 · Mykhailo Dalchenko🇺🇸 · Teruki Kamon🇺🇸 · Denis Rathjens🇺🇸 · Adrian Thompson🇺🇸

   We explore the physics of a new neutral gauge boson, ($Z^{\prime }$), coupling to only third-generation particles with a mass near the electroweak gauge boson mass poles. A $Z^{\prime }$ boson produced by top quarks and decaying to tau leptons is considered. With a simple search strategy inspired by existing analyses of the standard model gauge boson production in association with top quarks, we show that the Large Hadron Collider has good exclusionary power over the model parameter space of the $Z^{\prime }$ boson even at the advent of the high-luminosity era. It is shown that the $t\bar{t}{Z}^{\prime }$ process allows one to place limits on right-handed top couplings with a $Z^{\prime }$ boson that preferentially couples to third generation fermions, which are at present very weakly constrained.

   hep-phPLB(2020)·8 citations
4. 04*

   A study of $\Lambda$ and $\bar{\Lambda }$ polarization splitting by meson field in PICR hydrodynamic model

   Yilong Xie🇨🇳 · Gang Chen🇨🇳 · Laszlo Pal Csernai🇳🇴

   With the PICR hydrodynamic model, we study the polarization splitting between $\Lambda$ and $\bar{\Lambda }$ at RHIC BES energy range, based on the meson field mechanism. Our results fit to the experimental data fairly well. Besides, two unexpected effect emerges: (1) the baryon density gradient has non-trivial and negative contribution to the polarization splitting; (2) for 7.7 GeV Au+Au collisions within the centrality range of 20\%-50\%, the polarization splitting surprisingly increases with the centrality decreases. The second effect might help to explain the significant signal of polarization splitting measured in STAR's Au+Au 7.7 Gev collisions.

   hep-phnucl-thEPJC(2021)·34 citations
5. 05*

   Deconfinement and chiral phase transitions in quark matter with a strong electric field

   William R. Tavares🇧🇷 · Ricardo L. S. Farias🇧🇷 · Sidney S. Avancini🇧🇷

   The deconfinement and chiral phase transitions are studied in the context of the electrized quark matter at finite temperature in the two-flavor Polyakov-Nambu--Jona-Lasinio model. Using the mean field approximation and an electric field independet regularization we show that the effect of temperature and/or electric fields is to partially restore the chiral symmetry. The deconfinement phase transition is slightly affected by the magnitude of the electric field. To this end we show how the effective quark masses and the expectation value of the Polyakov Loop are affected by the electric fields at finite temperatures. As a very interesting result, the pseudocritical temperatures for chiral symmetry restoration and deconfinement decrease as we increase the magnitude of the electric fields, however, both start to increase after some critical value of the electric field.

   hep-phhep-lathep-thPRD(2020)·28 citations
6. 06*

   Nature of $X(3872)$ from the line shape

   Xian-Wei Kang🇨🇳 · J.A.Oller🇪🇸

   Using a general parameterization of two-body scattering amplitude, we systematically analyze the corresponding data on $X(3872)$, more explicitly, the CDF data on inclusive $p\bar{p}$ scattering to $J/\psi {\pi }^{+}{\pi }^{-}$, and the Belle and BaBar data on $B$ decays to $KJ/\psi {\pi }^{+}{\pi }^{-}$ and $KD{\bar{D}}^{\ast 0}$ around the $D^0{\bar{D}}^{\ast 0}$ threshold. We achieve a good reproduction of data and find that the $X(3872)$ can be interpreted as a bound and/or virtual state, or even higher-order (double or triple) virtual sate pole. The latter point was not realized previously in the literature. % The latter point has not been realized in other literatures. As a result, the compositeness of the $X(3872)$ can vary largely from nearly 0 to 1. More higher-precision data is needed to discriminate its pole structure and nature.

   hep-ph2 citations
7. 07*

   An Inverse Seesaw model with $A_4$-modular symmetry

   Takaaki Nomura🇰🇷 · Hiroshi Okada🇰🇷 · Sudhanwa Patra🇮🇳

   We discuss an inverse seesaw model based on right-handed fermion specific $U(1)$ gauge symmetry and $A_4$-modular symmetry. These symmetries forbid unnecessary terms and restrict structures of Yukawa interactions which are relevant to inverse seesaw mechanism. Then we can obtain some predictions in neutrino sector such as Dirac-CP phase and sum of neutrino mass, which are shown by our numerical analysis. Besides the relation among masses of heavy pseudo-Dirac neutrino can be obtained since it is also restricted by the modular symmetry. We also discuss implications to lepton flavor violation and collider physics in our model.

   hep-phNPB(2021)·124 citations
8. 08*

   Probing Electroweak Dark Matter at 14 TeV LHC

   Shuai Xu🇨🇳 · Sibo Zheng🇨🇳

   Well-motivated electroweak dark matter is often hosted by an extended electroweak sector which also contains new lepton pairs with masses near the weak scale. In this paper, we explore such electroweak dark matter via combining dark matter direct detections and high-luminosity LHC probes of new lepton pairs. Using $Z$- and $W$-associated electroweak processes with two or three lepton final states, we show that dependent on the overall coupling constant, dark matter mass up to $170-210$ GeV can be excluded at $2\sigma$ level and up to $175-205$ GeV can be discovered at $5\sigma$ level at the 14 TeV LHC with integrated luminosities 300 fb${}^{-1}$ and 3000 fb${}^{-1}$, respectively.

   hep-phastro-ph.COhep-exCPC(2020)·2 citations
9. 09*

   Enhanced Long-Lived Dark Photon Signals at the LHC

   Mingxuan Du🇨🇳 · Zuowei Liu🇨🇳 · Van Que Tran🇨🇳

   We construct a model in which the standard model is extended by a hidden sector with two gauge $U(1)$ bosons. A Dirac fermion $\psi$ charged under both $U(1)$ fields is introduced in the hidden sector which can be a subcomponent of the dark matter in the Universe. Stueckelberg mass terms between the two new gauge $U(1)$ fields and the hypercharge gauge boson mediate the interactions between the standard model sector and the hidden sector. A remarkable collider signature of this model is the enhanced long-lived dark photon events at the LHC than the conventional dark photon models; the long-lived dark photons in the model can be discriminated from the background by measuring the time delay signal in the precision timing detectors which are proposed to be installed in the LHC upgrades and have an $\mathcal{O}(10)$ pico-second detection efficiency. Searches with current LHCb data are also investigated. Various experimental constraints on the model including collider constraints and cosmological constraints are also discussed.

   hep-phJHEP(2020)·16 citations
10. 10*

    The role of angular ordering condition in Parton Branching transverse momentum dependent (TMD) PDFs and DY transverse momentum spectrum at LHC

    Aleksandra Lelek🇧🇪

    We discuss the parton branching (PB) evolution equation for transverse momentum dependent (TMD) parton distribution functions (PDFs), especially we concentrate on the angular ordering constrain and its effect on the TMD distributions. We discuss application of the PB TMDs to precise prediction of Drell-Yan transverse momentum spectrum at LHC, stressing the role of angular ordering in the low transverse momentum region. We compare the PB implementation of the angular ordering condition with the Kimber-Martin-Ryskin-Watt (KMRW), both at the analytical and numerical level.

    hep-phPoS(2020)·0 citations
11. 11*

    Constraints on Dark Matter from the Moon

    Raghuveer Garani🇧🇪 · Peter Tinyakov🇧🇪

    New and complimentary constraints are placed on the spin-independent interactions of dark matter with baryonic matter. Similar to the Earth and other planets, the Moon does not have any major internal heat source. We derive constraints by comparing the rate of energy deposit by dark matter annihilations in the Moon to 12 mW/m${}^2$ as measured by the Apollo mission. For light dark matter of mass $\mathcal{O}(10)$ GeV, we also examine the possibility of dark matter annihilations in the Moon limb. In this case, we place constraints by comparing the photon flux from such annihilations to that of the Fermi-LAT measurement of $10^{-4}$ MeV/cm${}^2$s. This analysis excludes spin independent cross section $\gtrsim 10^{-37}$ ${\mathrm{cm}}^2$ for dark matter mass between 30 and 50 GeV.

    hep-phastro-ph.COastro-ph.EPastro-ph.HEPLB(2020)·27 citations
12. 12*

    How to GAN away Detector Effects

    Marco Bellagente🇩🇪 · Anja Butter🇩🇪 · Gregor Kasieczka🇩🇪 · Tilman Plehn🇩🇪 · Ramon Winterhalder🇩🇪

    LHC analyses directly comparing data and simulated events bear the danger of using first-principle predictions only as a black-box part of event simulation. We show how simulations, for instance, of detector effects can instead be inverted using generative networks. This allows us to reconstruct parton level information from measured events. Our results illustrate how, in general, fully conditional generative networks can statistically invert Monte Carlo simulations. As a technical by-product we show how a maximum mean discrepancy loss can be staggered or cooled.

    hep-phcs.LGSciPost Phys.(2020)·143 citations
13. 13*

    Reconnection of magnetic fields in neutron stars driven by the electron mass term in the triangle anomaly

    Maxim Dvornikov🇷🇺 · Victor B. Semikoz (IZMIRAN)🇷🇺

    The Adler-Bell-Jackiw anomaly for massive particles is studied in an external magnetic field. The contributions of the mean spin and the pseudoscalar are accounted for in the quasiclassical approximation. The equation for the evolution of the magnetic helicity with the new quantum corrections is derived. We show that the quantum contribution to the helicity evolution can overcome the classical one in the dense degenerate matter which can be present in the core of a neutron star. The application of the obtained results for the interpretation of magnetar bursts are discussed.

    hep-phastro-ph.HEJ.Phys.Conf.Ser.(2019)·0 citations
14. 14*

    Determining Wino Lifetime in Supersymmetric Model at Future 100 TeV pp Colliders

    So Chigusa🇯🇵 · Yusuke Hosomi🇯🇵 · Takeo Moroi🇯🇵 · Masahiko Saito🇯🇵

    We discuss a possibility to measure the lifetime of charged Wino in supersymmetric model at future 100 TeV pp colliders, assuming that (neutral) Wino is the lightest superparticle (LSP). In the Wino LSP scenario, the charged Wino has a lifetime of about 0.2 ns, and its track may be reconstructed in particular by the inner pixel detectors. We show that the lifetime of charged Wino may be measured by using the information about the distribution of the flight lengths of charged Winos. We propose a procedure for the lifetime determination and show how the accuracy changes as we vary the mass spectrum of superparticle. We also discuss the effects of the detector layouts on the lifetime determination.

    hep-phPLB(2020)·4 citations
15. 15*

    Central exclusive meson production in proton-proton collisions in ALICE at the LHC

    R. Schicker (for the ALICE Collaboration)🇩🇪

    Central exclusive production at hadron colliders is characterised by the hadronic state produced at or close to midrapidity, and by the two forward scattered protons, or remnants thereof. No particles are produced between the midrapidity system and the forward going beam particles, and such events can hence be identified experimentally by a double-gap topology. At LHC energies, central exclusive production in proton-proton collisions is dominated by pomeron-pomeron fusion. The models to describe such reactions are reviewed, and the ongoing efforts in the ALICE Collaboration to analyse double-gap events taken in Run 2 at the LHC are presented.

    hep-phhep-ex4 citations
16. 16*

    Type II seesaw models with modular $A_4$ symmetry

    Tatsuo Kobayashi🇯🇵 · Takaaki Nomura🇰🇷 · Takashi Shimomura🇯🇵

    We discuss type-II seesaw models adopting modular $A_4$ symmetry in supersymmetric framework. In our approach, the models are classified by the assignment of $A_4$ representations and modular weights for leptons and triplet Higgs fields. Then neutrino mass matrix is characterized by modulus $\tau$ and two free parameters. Carrying out numerical analysis, we find allowed parameter sets which can fit the neutrino oscillation data. For the allowed parameter sets, we obtain the predictions in neutrino sector such as CP violating phases and the lightest neutrino mass. Finally we also show the predictions for the branching ratios of doubly charged scalar boson focusing on the case where the doubly charged scalar boson dominantly decays into charged leptons.

    hep-phPRD(2020)·112 citations
17. 17*

    The anomalous production of multi-lepton and its impact on the measurement of $Wh$ production at the LHC

    Yesenia Hernandez🇿🇦 · Mukesh Kumar🇿🇦 · Alan S. Cornell🇿🇦 · Salah-Eddine Dahbi🇿🇦 · Yaquan Fang🇨🇳 · Benjamin Lieberman🇿🇦 · Bruce Mellado🇿🇦 · Kgomotso Monnakgotla🇿🇦 · Xifeng Ruan🇿🇦 · Shuiting Xin🇨🇳

    Anomalies in multi-lepton final states at the Large Hadron Collider (LHC) have been reported in Refs.~\cite{vonBuddenbrock:2017gvy,vonBuddenbrock:2019ajh}. These can be interpreted in terms of the production of a heavy boson, $H$, decaying into a Standard Model (SM) Higgs boson, $h$, and a singlet scalar, $S$, which is treated as a SM Higgs-like boson. This process would naturally affect the measurement of the $Wh$ signal strength at the LHC, where $h$ is produced in association with leptons and di-jets. Here, $h$ would be produced with lower transverse momentum, $p_{Th}$, compared to SM processes. Corners of the phase-space are fixed according to the model parameters derived in Refs.~\cite{vonBuddenbrock:2016rmr,vonBuddenbrock:2017gvy} without additional tuning, thus nullifying potential look-else-where effects or selection biases. Provided that no stringent requirements are made on $p_{Th}$ or related observables, the signal strength of $Wh$ is $\mu (Wh)=2.41\pm 0.37$. This corresponds to a deviation from the SM of $3.8\sigma$. This result further strengthens the need to measure with precision the SM Higgs boson couplings in $e^{+}{e}^{-}$, and $e^{-}p$ collisions, in addition to $pp$ collisions.

    hep-phhep-exEPJC(2021)·35 citations
18. 18*

    Study of the radiative decay $J/\psi \to {\eta }_c+\gamma$ in light cone sum rules

    Song-Pei Guo🇨🇳 · Yan-Jun Sun🇨🇳 · Wei Hong🇨🇳 · Qi Huang🇨🇳 · Guo-Hua Zhao🇨🇳

    At present, there are many experimental and theoretical results for $J/\psi \to {\eta }_c+\gamma$ process, while the results are inconsistent based on different methods and considerations. In this paper, the light cone sum rules method is used in studying the radiative decay $J/\psi \to {\eta }_c+\gamma$. We give the transition form factor of this process based on the leading twist distribution amplitude of ${\eta }_c$ meson, with this form factor further obtain the decay width. Our result is consistent with those of other sum rules. A comparison of our result with others' about the decay width is also presented.

    hep-phnucl-thNPB(2020)·8 citations
19. 19*

    Two mass scales for the Higgs field?

    Paolo Cea🇮🇹 · Maurizio Consoli🇮🇹 · Leonardo Cosmai🇮🇹

    In the original version of the theory, the driving mechanism for spontaneous symmetry breaking was identified in the pure scalar sector. However, this old idea requires a heavy Higgs particle that, after the discovery of the 125 GeV resonance, seems to be ruled out. We argue that this is not necessarily true. If the phase transition is weakly first order, as indicated by most recent lattice simulations, one should consider those approximation schemes that are in agreement with this scenario. Then, even in a simple one-component theory, it becomes natural to introduce two mass scales, say $M_h$ and $m_h$ with $m_h\ll M_h$. This resembles the coexistence of phonons and rotons in superfluid helium-4, which is the non-relativistic analogue of the scalar condensate, and is potentially relevant for the Standard Model. In fact, vacuum stability would depend on $M_h$ and not on $m_h$ and be nearly insensitive to the other parameters of the theory (e.g. the top quark mass). By identifying $m_h=125$ GeV, and with our previous estimate from lattice simulations $M_h=754\pm 20(\mathrm{stat})\pm 20(\mathrm{syst})$ GeV, we thus get in touch with a recent, independent analysis of the ATLAS + CMS data which claims experimental evidence for a scalar resonance around $700$ GeV.

    hep-phhep-th1 citation
20. 20*

    QFT with FDR

    Roberto Pittau🇪🇸

    I discuss the latest developments of FDR in the context of quantum field theory calculations relevant for high-energy particle physics phenomenology. In particular, I focus on NNLO computations and on the use of FDR in connection with effective field theories.

    hep-phhep-th0 citations
21. 21*

    Classifying Accidental Symmetries in Multi-Higgs Doublet Models

    Neda Darvishi🇬🇧 · Apostolos Pilaftsis🇬🇧

    The potential of $n$-Higgs Doublet Models ($n$HDMs) contains a large number of SU(2)${}_L$-preserving accidental symmetries as subgroups of the symplectic group Sp(2$n)$. To classify these, we introduce prime invariants and irreducible representations in bilinear field space that enable us to explicitly construct accidentally symmetric $n$HDM potentials. We showcase the classifications of symmetries and present the relationship among the theoretical parameters of the scalar potential for; (i) the Two Higgs Doublet Model (2HDM) and (ii) the Three Higgs Doublet Model (3HDM). We recover the maximum number of $13$ accidental symmetries for the 2HDM potential and for the first time, we present the complete list of $40$ accidental symmetries for the 3HDM potential.

    hep-phPRD(2020)·57 citations
22. 22*

    Leptoquarks in B-meson anomalies: simplified models and HL-LHC discovery prospects

    Natascia Vignaroli🇮🇹

    I will review simplified models with leptoquarks, which can explain recent anomalies in $B$-meson physics, and I will indicate the High-Luminosity LHC prospects for testing these theories, with a special focus to the efficient channel of pair leptoquark production in the $t\bar{t}$ plus missing energy final state.

    hep-phhep-exNuovo Cim.C(2020)·6 citations
23. 23*

    Gravitational wave probes of axion-like particles

    Camila S. Machado🇩🇪 · Wolfram Ratzinger🇩🇪 · Pedro Schwaller🇩🇪 · Ben A. Stefanek🇩🇪

    We have recently shown that axions and axion-like particles (ALPs) may emit an observable stochastic gravitational wave (GW) background when they begin to oscillate in the early universe. In this note, we identify the regions of ALP parameter space which may be probed by future GW detectors, including ground- and space-based interferometers and pulsar timing arrays. Interestingly, these experiments have the ability to probe axions from the bottom up, i.e. in the very weakly coupled regime which is otherwise unconstrained. Furthermore, we discuss the effects of finite dark photon mass and kinetic mixing on the mechanism, as well as the (in)sensitivity to couplings of the axion to Standard Model fields. We conclude that realistic axion and ALP scenarios may indeed be probed by GW experiments in the future, and provide signal templates for further studies.

    hep-phastro-ph.COPRD(2020)·95 citations
24. 24*

    Neutrino and Positron Constraints on Spinning Primordial Black Hole Dark Matter

    Basudeb Dasgupta🇮🇳 · Ranjan Laha🇨🇭 · Anupam Ray🇮🇳

    Primordial black holes can have substantial spin -- a fundamental property that has a strong effect on its evaporation rate. We conduct a comprehensive study of the detectability of primordial black holes with non-negligible spin, via the searches for the neutrinos and positrons in the MeV energy range. Diffuse supernova neutrino background searches and observation of the 511 keV gamma-ray line from positrons in the Galactic center set competitive constraints. Spinning primordial black holes are probed up to a slightly higher mass range compared to non-spinning ones. Our constraint using neutrinos is slightly weaker than that due to the diffuse gamma-ray background, but complementary and robust. Our positron constraints are typically weaker in the lower mass range and stronger in the higher mass range for the spinning primordial black holes compared to the non-spinning ones. They are generally stronger than those derived from the diffuse gamma-ray measurements for primordial black holes having masses greater than a few $\times 10^{16}$g.

    hep-phastro-ph.COastro-ph.HEgr-qc+1PRL(2020)·241 citations
25. 25*

    Transverse momentum spectra of strange hadrons within extensive and nonextensive statistics

    Hayam Yassin🇪🇬 · Eman R. Abo Elyazeed (Ain Shams U., Cairo)🇪🇬 · Abdel Nasser Tawfik (Nile U., ECTP)🇪🇬

    Using generic (non)extensive statistics, in which the underlying system autonomously manifests its extensive and nonextensive statistical nature, we extract various fit parameters from the CMS experiment and compare these to the corresponding results obtained from Tsallis and Boltzmann statistics. The present study is designed to indicate the possible variations between the three types of statistical approaches and characterizes their dependence on collision energy, multiplicity, and size of the system of interest. We analyze the transverse momentum spectra $p_T$ of the strange hadrons \Kslxi produced in Pb+Pb collisions, at 2.76 TeV, in p+Pb collisions, at 5.02 TeV, and in $p+p$ collisions, at 7 TeV. From the comparison of the resulting fit parameters; temperature $T$, volume $V$, and nonextensvie parameter $d$, with calculations based on Tsallis and Boltzmann statistics, remarkable differences between the three types of statistics are determined besides a strong dependence on size and type of the colliding system. We conclude that the produced particles with large masses and large strange quantum numbers likely freeze out earlier than the ones with smaller masses and less strange quantum numbers. This conclusion seems not depending on the type of the particle or the collision but apparently manifesting transitions from chemical (larger temperature) to the kinetic freezeouts (lower temperature). For the first university (equivalent) class c=1, the decrease in the second one, $d$, with increasing energy and collision centrality highlights that the system departs from nonextensivity (non-equilibrium) and apparently approaches extensivity (equilibrium) indicating that the Boltzmann statistics becomes the proper statistical approach in describing that system. Last but not least, we present analytical expressions for the energy dependence of the various fit parameters.

    hep-phPhys.Scripta(2020)·12 citations
26. 26*

    Type-I 2HDM under the Higgs and Electroweak Precision Measurements

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

    We explore the extent to which future precision measurements of the Standard Model (SM) observables at the proposed $Z$-factories and Higgs factories may have impacts on new physics beyond the Standard Model, as illustrated by studying the Type-I Two-Higgs-doublet model (Type-I 2HDM). We include the contributions from the heavy Higgs bosons at the tree-level and at the one-loop level in a full model-parameter space. While only small $\tan \beta$ region is strongly constrained at tree level, the large $\tan \beta$ region gets constrained at loop level due to $\tan \beta$ enhanced tri-Higgs couplings. We perform a multiple variable global fit with non-alignment and non-degenerate masses. We find that the allowed parameter ranges could be tightly constrained by the future Higgs precision measurements, especially for small and large values of $\tan \beta$. Indirect limits on the masses of heavy Higgs bosons can be obtained, which can be complementary to the direct searches of the heavy Higgs bosons at hadron colliders. We also find that the expected accuracies at the $Z$-pole and at a Higgs factory are quite complementary in constraining mass splittings of heavy Higgs bosons. The typical results are $|\cos (\beta -\alpha )|<0.05,|\Delta m_{\Phi }|<200\mathrm{GeV}$, and $\tan \beta \gtrsim 0.3$. The reaches from CEPC, FCCee and ILC are also compared, for both Higgs and $Z$-pole precision measurements. Comparing to the Type-II 2HDM, the 95\% C.L. allowed range of $\cos (\beta -\alpha )$ is larger, especially for large values of $\tan \beta$.

    hep-phJHEP(2020)·42 citations
27. 27*

    Study on ${\Xi }_{cc}\to {\Xi }_c$ and ${\Xi }_{cc}\to {\Xi }_c^{\prime }$ weak decays in the light-front quark model

    Hong-Wei Ke🇨🇳 · Fang Lu🇨🇳 · Xiao-Hai Liu🇨🇳 · Xue-Qian Li🇨🇳

    In this work we study the weak decays of ${\Xi }_{cc}\to {\Xi }_c$ and ${\Xi }_{cc}\to {\Xi }_c^{\prime }$ in the light-front quark model. Generally, a naive, but reasonable conjecture suggests that the $cc$ subsystem in ${\Xi }_{cc}$ ( $us$ pair in ${\Xi }_c^{{(}^{\prime })}$) stands as a diquark with definite spin and color assignments. During the concerned processes, the diquark of the initial state is not a spectator, and must be broken. A Racah transformation would decompose the original $(cc)q$ into a combination of $c(cq)$ components. Thus we may deal with the decaying $c$ quark alone while keeping the $(cq)$ subsystem as a spectator. With the re-arrangement of the inner structure we calculate the form factors numerically and then obtain the rates of semi-leptonic decays and non-leptonic decays, which will be measured in the future.

    hep-phEPJC(2020)·38 citations
28. 28*

    Pion mass dependence of the electromagnetic form factors of singly heavy baryons

    June-Young Kim🇰🇷 · Hyun-Chul Kim🇰🇷

    We study the electromagnetic form factors of the lowest-lying singly heavy baryons with spin 1/2 within the framework of the chiral quark-soliton model, focusing on the comparison with recent lattice data. To compare the present results quantitatively with the lattice data, it is essential to treat the pion mass as a variable parameter, i.e., to employ the unphysical values of the pion mass, which are used in lattice calculations. While the results with the physical value of the pion mass fall off faster than those from the lattice calculations as the momentum transfer increases, the extrapolated results with larger pion masses get closer to the lattice data.

    hep-phhep-exhep-latPTEP(2021)·16 citations
29. 29*

    Stable Three Generation Standard--like Model From a Tachyonic Ten Dimensional Heterotic--String Vacuum

    Alon E. Faraggi🇬🇧 · Viktor G. Matyas🇬🇧 · Benjamin Percival🇬🇧

    Recently it was proposed that the ten dimensional tachyonic superstring vacua may serve as good starting points for the construction of viable phenomenological models. Such phenomenologically viable models enlarge the space of possible string solutions, and may offer novel insight into some of the outstanding problems in string phenomenology. In this paper we present a three generation standard--like model that may be regarded as a compactification of a ten dimensional tachyonic vacuum. We discuss the features of the model as compared to a similar model that may be regarded as compactification of the ten dimensional $SO(16)\times SO(16)$ heterotic-string. We further argue that in the four dimensional model all the geometrical moduli are fixed perturbatively, whereas the dilaton may be fixed by hidden sector non--perturbative effects.

    ↳ hep-thhep-phEPJC(2020)·34 citations
30. 30*

    Algorithms and tools for iterated Eisenstein integrals

    Claude Duhr🇨🇭 · Lorenzo Tancredi🇬🇧

    We present algorithms to work with iterated Eisenstein integrals that have recently appeared in the computation of multi-loop Feynman integrals. These algorithms allow one to analytically continue these integrals to all regions of the parameter space, and to obtain fast converging series representations in each region. We illustrate our approach on the examples of hypergeometric functions that evaluate to iterated Eisenstein integrals as well as the well-known sunrise graph.

    ↳ hep-thhep-phJHEP(2020)·57 citations
31. 31*

    On self-similar axion-dilaton configurations

    Riccardo Antonelli🇮🇹 · Ehsan Hatefi🇮🇹

    We explore self-similar collapse solutions to the Einstein-axion-dilaton system in arbitrary spacetime dimensions, which are invariant under spacetime dilation combined with internal $SL(2,R)$ transformations. We set up a numerical formalism, and test it in four and five dimensions, discovering several new families of solutions in the three conjugacy classes of $SL(2,R)$.

    ↳ hep-thgr-qchep-phmath-ph+1JHEP(2020)·10 citations
32. 32*

    T-Model Inflation and Bouncing Cosmology

    David Sloan🇬🇧 · Konstantinos Dimopoulos🇬🇧 · Sotirios Karamitsos🇬🇧

    We examine the dynamics of a closed cosmology whose matter source is that of a conformally coupled scalar field with a broken $\mathrm{SO}(1,1)$ symmetry, which correspond to the $\alpha$-attractors proposed by Linde and Kallosh. Following a field redefinition, such models give rise to "T-model" inflationary potentials, whose dynamics provide both an inflationary phase and a classical bounce. We show that the universe can undergo bounces far from the regime of quantum gravity. We analyse perturbations on this background with particular attention given to the effects of a double-bouncing scenario (with rapid recollapse between bounces) on the long wavelength modes. We demonstrate that the predictions of such models agree well with observations and might explain the suppression of power in the low multiples of the CMB.

    ↳ gr-qcastro-ph.COhep-phhep-thPRD(2020)·15 citations
33. 33*

    Can Non-standard Recombination Resolve the Hubble Tension?

    Miaoxin Liu🇨🇳 · Zhiqi Huang🇨🇳 · Xiaolin Luo🇨🇳 · Haitao Miao🇨🇳 · Naveen K. Singh🇨🇳 · Lu Huang🇨🇳

    The inconsistent Hubble constant values derived from cosmic microwave background (CMB) observations and from local distance-ladder measurements may suggest new physics beyond the standard $\Lambda$CDM paradigm. It has been found in earlier works that, at least phenomenologically, non-standard recombination histories can reduce the $\gtrsim 4\sigma$ Hubble tension to $\sim 2\sigma$. Following this path, we vary physical and phenomenological parameters in RECFAST, the standard code to compute ionization history of the universe, to explore possible physics beyond standard recombination. We find that the CMB constraint on the Hubble constant is sensitive to the Hydrogen ionization energy and $2s\to 1s$ two-photon decay rate, both of which are atomic constants, and is insensitive to other details of recombination. Thus, the Hubble tension is very robust against perturbations of recombination history, unless exotic physics modifies the atomic constants during the recombination epoch.

    ↳ astro-ph.COgr-qchep-phhep-thSCPMA(2020)·67 citations
34. 34*

    Goldstone Boson Effects on Vacuum Decay

    Mulham Hijazi🇬🇧 · Apostolos Pilaftsis🇬🇧

    We study the effects of Goldstone modes on the stability of the vacuum in a $U(1)$ theory for a complex scalar field. The dynamics of the field resemble those of Keplerian motion in the presence of time-dependent friction, whose equations of motion imply a conserved quantity, $L$, reminiscent of conserved angular momentum. They also imply a persistent infinite barrier at $\rho =0$ and a divergent field value at the origin of coordinates in flat spacetime, rendering any solution physically unattainable. However, in a spacetime punctured at the origin of coordinates, we find finite-action solutions to the equations of motion, which correspond to the size of the hole $a_0$, which in turn determines the tunneling point ${\rho }_0$ and $L$. We find that the rates of vacuum decay get drastically enhanced by many orders of magnitude for all possible orderings in which the false and true vacua are placed in the potential. Finally, we show how Goldstone modes provide the necessary energy to overcome drag forces yielding finite-action solutions for any potential, including those that no such solutions exist for real scalar fields.

    ↳ hep-thhep-phNPB(2020)·1 citation
35. 35*

    $H_0$ tension and the String Swampland

    Luis A. Anchordoqui🇺🇸 · Ignatios Antoniadis🇫🇷 · Dieter Lust🇩🇪 · Jorge F. Soriano🇺🇸 · Tomasz R. Taylor🇺🇸

    [Abridged] We realize the Agrawal-Obied-Vafa (AOV) swampland proposal of fading dark matter by the model of Salam-Sezgin and its string realization of Cvetic-Gibbons-Pope. The model describes a compactification of 6-dimensional supergravity with a monopole background on a 2-sphere. In 4 dimensions, there are 2 scalar fields, $X$ and $Y$, and the effective potential in the Einstein frame is an exponential with respect to $Y$ times a quadratic polynomial in the field $e^{-X}$. When making the volume of the 2-sphere large, namely for large values of $Y$, there appears a tower of states, which according to the infinite distance swampland conjecture becomes exponentially massless. If the standard model fields are confined on Neveu-Schwarz 5-branes the 6-dimensional gauge couplings are independent of the string dilaton in the string frame, and upon compactification to 4 dimensions the 4-dimensional gauge couplings depend on $X$ (rather than the dilaton $Y$) which is fixed at the minimum of the potential. This avoids direct couplings of the dilaton to matter suppressing extra forces competing with gravity. We show that this set up has the salient features of the AOV models, and ergo can potentially ameliorate the tension between local distance ladder and cosmic microwave background estimates of the Hubble constant $H_0$. Although the AOV proposal does not fully resolve the tension in $H_0$ measurements, it provides a dynamical dark energy model of cosmology that satisfies the de Sitter swampland conjecture. We comment on a viable solution to overcome the tension between low- and high-redshift observations within the AOV background and discuss the implications for the swampland program.

    ↳ hep-thastro-ph.COhep-phPRD(2020)·56 citations
36. 36*

    Fast Neutrino Flavor Instability in the Neutron-star Convection Layer of Three-dimensional Supernova Models

    Robert Glas (1,2)🇩🇪 · H.-Thomas Janka (1)🇩🇪 · Francesco Capozzi (3)🇩🇪 · Manibrata Sen (4,5)🇺🇸 · Basudeb Dasgupta (6)🇮🇳 · Alessandro Mirizzi (7,8)🇮🇹 · Guenter Sigl (9) ((1) MPI Astrophysics, Garching, (2) TUM, Munich, (3) MPI Physik, Munich, (4) UC Berkeley, Berkeley, (5) Northwestern University, Evanston, (6) Tata Institute of Fundamental Research, Mumbai, (7) Dipartimento Interateneo di Fisica, Bari, (8) Istituto Nazionale di Fisica Nucleare, Bari, (9) Inst. Theor. Physik, Hamburg University)🇩🇪

    Neutrinos from a supernova (SN) might undergo fast flavor conversions near the collapsed stellar core. We perform a detailed study of this intriguing possibility, analyzing time-dependent state-of-the-art 3D SN models of 9 and 20 Msun. Both models were computed with multi-D three-flavor neutrino transport based on a two-moment solver, and both exhibit the presence of the lepton-number emission self-sustained asymmetry (LESA). The transport solution does not provide the angular distributions of the neutrino fluxes, which are crucial to track the fast flavor instability. To overcome this limitation, we use a recently proposed approach based on the angular moments of the energy-integrated electron lepton-number distribution. With this method we find the possibility of fast neutrino flavor instability at radii <~20 km, which is well interior to the neutrinosphere. Our results confirm recent observations in a 2D SN model and in 2D/3D models with fixed matter background, which were computed with Boltzmann neutrino transport. However, the flavor unstable locations are not isolated points as discussed previously, but thin skins surrounding volumes where electron antineutrinos are more abundant than electron neutrinos. These volumes grow with time and appear first in the convective layer of the proto-neutron star (PNS), where a decreasing electron fraction (Ye) and high temperatures favor the occurrence of regions with negative neutrino chemical potential. Since Ye remains higher in the LESA dipole direction, where convective lepton-number transport out from the nonconvective PNS core slows down the deleptonization, flavor unstable conditions become more widespread in the opposite hemisphere. This interesting phenomenon deserves further investigation, since its impact on SN modeling and possible consequences for SN dynamics and neutrino observations are presently unclear. (abridged)

    ↳ astro-ph.HEhep-phPRD(2020)·121 citations
37. 37*

    Exploring the QCD phase diagram at finite density by the complex Langevin method on a $16^3\times 32$ lattice

    Shoichiro Tsutsui🇯🇵 · Yuta Ito🇯🇵 · Hideo Matsufuru🇯🇵 · Jun Nishimura🇯🇵 · Shinji Shimasaki🇯🇵 · Asato Tsuchiya🇯🇵

    We explore the QCD phase diagram at finite density with four-flavor staggered fermions using the complex Langevin method, which is a promising approach to overcome the sign problem. In our previous work on an $8^3\times 16$ lattice at $\beta =5.7$ with the quark mass $m=0.01$, we have found that the baryon number density has a clear plateau as a function of the chemical potential. In this study, we use a $16^3\times 32$ lattice to reduce finite volume effects and find that the plateau structure survives. Moreover, the number of quarks in the plateau region turns out to be 24, which is exactly the same as the one obtained previously on the $8^3\times 16$ lattice. We provide a simple interpretation of this number, which suggests that the Fermi sphere is starting to form.

    ↳ hep-lathep-phPoS(2019)·11 citations
38. 38*

    Searching for New Physics with $b\bar{b}{\ell }^{+}{\ell }^{-}$ Contact Interactions

    Yoav Afik🇮🇱 · Shaouly Bar-Shalom🇮🇱 · Jonathan Cohen🇮🇱 · Yoram Rozen🇮🇱

    We study the impact of contact interactions involving two leptons (electrons or muons) and two $b$-quarks ($b\bar{b}{\ell }^{+}{\ell }^{-}$) on the high-mass di-lepton region at the LHC. We consider different selections of $b$-tagged jet multiplicities in the di-lepton final states: inclusive (no selection), 0, 1 and 2 $b$-tagged jets, and show that the single $b$-jet selection significantly improves the sensitivity to New Physics (NP) in the form of the $b\bar{b}{\ell }^{+}{\ell }^{-}$ contact term. We obtain a better sensitivity compared to the currently existing searches of NP in the di-lepton inclusive channel. In particular, the expected limits go beyond competitive bounds set by LEP (for electrons) on the scale of NP, $\Lambda$, by a factor of $1.2-3.1$, depending on the chirality structure of the operator. In addition, the expected limits on $\Lambda$, set by using a non-resonant LHC di-lepton inclusive search, are expected to be improved by a factor of $1.3-1.4$ for both electrons and muons.

    ↳ hep-exhep-phPLB(2020)·47 citations
39. 39*

    Revisiting pre-inflationary universe of family of $\alpha -$attractor in loop quantum cosmology

    M. Shahalam🇨🇳 · Mudhahir Al Ajmi🇴🇲 · R. Myrzakulov🇰🇿 · Anzhong Wang🇺🇸

    In this work, we revisit the dynamics of pre-inflationary universe with a family of $\alpha -$attractor potentials, in the framework of loop quantum cosmology, in which the big bang singularity is generically resolved purely with quantum geometric effects, and replaced by a quantum bounce. At the bounce, the background evolution is divided into two distinct classes, the first is dominated by the kinetic energy of the inflaton field and the second by the potential energy. In both classes, we find the physically viable initial conditions numerically that provide not only the slow-roll inflation, but also sufficient e-folds to be compatible with observations. In the entire range of kinetic energy dominated initial conditions (except some subsets of Models 2 and 4), the background evolution prior to reheating is always split into three different phases: bouncing, transition and slow-roll inflation. In the bouncing phase, the numerical evolution of the scale factor is independent not only of the initial data, but also the inflationary potentials, as long as it is dominated by the kinetic energy, and can be well approximated by an analytical solution, whereas in the potential energy dominated case, such approximated results do not exist. Moreover, we study the phase space analysis for a class of $\alpha -$attractor potentials, and discuss the phase space trajectories for physically viable initial conditions of the inflaton field.

    ↳ gr-qcastro-ph.COhep-phhep-thClass.Quant.Grav.(2020)·19 citations
40. 40*

    Symmetries of the light hadron spectrum in high temperature QCD

    C. Rohrhofer🇯🇵 · Y. Aoki🇯🇵 · G. Cossu🇬🇧 · H. Fukaya🇯🇵 · C. Gattringer🇦🇹 · L.Ya. Glozman🇦🇹 · S. Hashimoto🇯🇵 · C.B. Lang🇦🇹 · K. Suzuki🇯🇵

    Properties of QCD matter change significantly around the chiral crossover temperature, and the effects on $U(1{)}_A$ and topological susceptibilities, as well as the meson spectrum have been studied with much care. Baryons and the effect of parity doubling in this temperature range have been analyzed previously by various other groups employing different setups. Here we construct suitable operators to investigate chiral and axial $U(1{)}_A$ symmetries in the baryon spectrum. Measurements for different volumes and quark-masses are done with two flavors of chirally symmetric domain-wall fermions at temperatures above the critical one. The possibility of emergent $SU(4)$ and $SU(2{)}_{CS}$ symmetries is discussed.

    ↳ hep-lathep-phPoS(2020)·8 citations
41. 41*

    Heavy quark momentum diffusion coefficient from the lattice

    Nora Brambilla🇩🇪 · Viljami Leino🇩🇪 · Peter Petreczky🇺🇸 · Antonio vairo🇩🇪

    We report progress towards computing the heavy quark momentum diffusion coefficient from the lattice correlator of two chromoelectric fields attached to a Polyakov loop in pure SU(3) gauge theory. Using a multilevel algorithm and tree-level improvement, we study the behavior of the diffusion coefficient as a function of temperature in the wide range $1.1<T/Tc<10^4$.

    ↳ hep-lathep-phnucl-thPoS(2019)·8 citations
42. 42*

    The role of the chiral phase transition in modelling the kaon to pion ratio

    A. V. Friesen🇷🇺 · Yu. L. Kalinovsky🇷🇺 · V. D. Toneev🇷🇺

    A sharp peak in the $K^{+}/{\pi }^{+}$ ratio in relativistic heavy-ion collision is discussed in the framework of the SU(3) Polyakov-loop extended NJL model with vector interaction. In the model, the $K^{+}/{\pi }^{+}$ ratio was calculated along the chiral phase transition line for different values of the vector coupling $g_V$. We showed that the value of the vector coupling had no significant effect on the $K^{+}/{\pi }^{+}$ behaviour.

    ↳ nucl-thhep-phJETP Lett.(2020)·1 citation
43. 43*

    Gauge Independence of Induced Gravitational Waves

    Keisuke Inomata🇯🇵 · Takahiro Terada🇰🇷

    We study gauge (in)dependence of the gravitational waves (GWs) induced from curvature perturbations. For the GWs produced in a radiation-dominated era, we find that the observable (late-time) GWs in the TT gauge and in the Newtonian gauge are the same in contrast to a claim in the literature. We also mention the interpretation of the gauge dependence of the tensor perturbations which appears in the context of the induced GWs.

    ↳ gr-qcastro-ph.COhep-phPRD(2020)·149 citations
44. 44*

    Scalar Induced Gravitational Waves in Different Gauges

    Chen Yuan🇨🇳 · Zu-Cheng Chen🇨🇳 · Qing-Guo Huang🇨🇳

    In this letter we calculate the scalar induced gravitational waves (SIGWs) accompanying the formation of primordial black hole during the radiation dominated era in three different gauges, i.e. synchronous gauge, Newton gauge and uniform curvature gauge, and we find that the energy density spectra of SIGWs, $\text{ogw}(k)$, are identical in these three different gauges.

    ↳ astro-ph.COgr-qchep-phhep-thPRD(2020)·137 citations
45. 45*

    Gravimeter search for compact dark matter objects moving in the Earth

    C. J. Horowitz🇺🇸 · R. Widmer-Schnidrig🇩🇪

    Dark matter could be composed of compact dark objects (CDOs). These objects may interact very weakly with normal matter and could move freely {\it inside} the Earth. A CDO moving in the inner core of the Earth will have an orbital period near 55 min and produce a time dependent signal in a gravimeter. Data from superconducting gravimeters rule out such objects moving inside the Earth unless their mass $m_D$ and or orbital radius $a$ are very small so that $m_{D}a<1.2\times 10^{-13}{M}_{\oplus }{R}_{\oplus }$. Here $M_{\oplus }$ and $R_{\oplus }$ are the mass and radius of the Earth.

    ↳ astro-ph.EPastro-ph.HEhep-phnucl-thPRL(2020)·15 citations
46. 46*

    On bubble collisions in strongly supercooled phase transitions

    Marek Lewicki🇬🇧 · Ville Vaskonen🇬🇧

    We study strongly supercooled cosmological phase transitions. We perform numerical lattice simulations of two-bubble collisions and demonstrate that, depending on the scalar potential, in the collision the field can either bounce to a false vacuum or remain oscillating around the true vacuum. We study if these cases can be distinguished from their gravitational wave signals and discuss the possibility of black hole formation in the bubble collisions.

    ↳ astro-ph.COhep-phPhys.Dark Univ.(2020)·99 citations
47. 47*

    Gravity and Matters on a pure geometric thick polynomial $f(R)$ brane

    Heng Guo🇨🇳 · Lang-Lang Wang🇨🇳 · Chun-E Fu🇨🇳 · Qun-Ying Xie🇨🇳

    In this paper, the solutions of the pure geometric thick $f(R)$ brane are investigated. The formulation of $f(R)$ is chosen as $f(R)={\sum }_{i=1}^n{a}_i{R}^i+\Lambda$. For the certain value of $n$, the brane solution can be calculated, and when $n=3$, $n=4$, and $n=10$, the thick brane solutions are presented. The solutions is stable under linear tensor fluctuation. The zero mode of gravity and scalar field can be localized on thick $f(R)$ branes naturally. The zero mode of vector field and left-chiral fermion can be localized on thick $f(R)$ branes by introducing the coupling with scalar curvature $R$ of spacetime, and the massive resonant modes can be quasilocalized on the brane with the large coupling coefficients.

    ↳ hep-thgr-qchep-phPRD(2023)·21 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.