Tue·May 29, 2018Tuesday·May 29, 2018

1. 01*

   GeV-Scale Thermal WIMPs: Not Even Slightly Dead

   Rebecca K. Leane🇺🇸 · Tracy R. Slatyer🇺🇸 · John F. Beacom🇺🇸 · Kenny C. Y. Ng🇮🇱

   Weakly Interacting Massive Particles (WIMPs) have long reigned as one of the leading classes of dark matter candidates. The observed dark matter abundance can be naturally obtained by freezeout of weak-scale dark matter annihilations in the early universe. This "thermal WIMP" scenario makes direct predictions for the total annihilation cross section that can be tested in present-day experiments. While the dark matter mass constraint can be as high as $m_{\chi }\gtrsim 100$ GeV for particular annihilation channels, the constraint on the total cross section has not been determined. We construct the first model-independent limit on the WIMP total annihilation cross section, showing that allowed combinations of the annihilation-channel branching ratios considerably weaken the sensitivity. For thermal WIMPs with s-wave $2\to 2$ annihilation to visible final states, we find the dark matter mass is only known to be $m_{\chi }\gtrsim 20$ GeV. This is the strongest largely model-independent lower limit on the mass of thermal-relic WIMPs, together with the upper limit on the mass from the unitarity bound ($m_{\chi }\lesssim 100$ TeV), it defines what we call the "WIMP window". To probe the remaining mass range, we outline ways forward.

   hep-phastro-ph.COastro-ph.HEPRD(2018)·234 citations
2. 02*

   Study of Gauged Lepton Symmetry Signatures at Colliders

   We-Fu Chang🇹🇼 · John N. Ng🇨🇦

   We construct a new gauged $U(1{)}_{\ell }$ lepton number model which is anomaly-free for each SM generation. The active neutrino masses are radiatively generated with a minimal scalar sector. The phenomenology and collider signals are studied. The interference effects among the new gauge boson, $Z_{\ell }$, photon, and $Z$-boson can be probed at the future $e^{+}{e}^{-}$ colliders even if the center-of-mass energy is below the mass of $Z_{\ell }$. Moreover, the electroweak precision sets a stringent bound on the mass splitting of the new lepton doublets.

   hep-phPRD(2018)·10 citations
3. 03*

   Dispersion Theory in Electromagnetic Interactions

   B. Pasquini (Pavia U. & INFN, Pavia)🇮🇹 · M. Vanderhaeghen (Mainz U., Inst. Kernphysik & U. Mainz, PRISMA)🇩🇪

   We review various applications of dispersion relations (DRs) to the electromagnetic structure of hadrons. We discuss the way DRs allow one to extract information on hadron structure constants by connecting information from complementary scattering processes. We consider the real and virtual Compton scattering processes off the proton, and summarize recent advances in the DR analysis of experimental data to extract the proton polarizabilities, in comparison with alternative studies based on chiral effective field theories. We discuss a multipole analysis of real Compton scattering data, along with a DR fit of the energy-dependent dynamical polarizabilities. Furthermore, we review new sum rules for the double-virtual Compton scattering process off the proton, which allow for model independent relations between polarizabilities in real and virtual Compton scattering, and moments of nucleon structure functions. The information on the double-virtual Compton scattering is used to predict and constrain the polarizability corrections to muonic hydrogen spectroscopy.

   hep-phhep-exnucl-exnucl-thAnn.Rev.Nucl.Part.Sci.(2018)·40 citations
4. 04*

   Possibility of observing Higgs bosons at the ILC in the lepton-specific 2HDM

   Majid Hashemi🇮🇷

   The Higgs boson pair production at a linear $e^{+}{e}^{-}$ collider is analyzed in the $4\tau$ final state in the context of lepton-specific or type IV 2HDMs. Both beams are assumed to be unpolarized. The Higgs boson pairs (HA) are produced through off-shell $Z^{\ast }$ production and decay to $\tau$-jets which is the main decay channel for neutral Higgs bosons in type IV. Using a simplified detector simulation based on SiD detector at ILC, the 4$\tau$ signal is studied through the $\tau$-jet pair invariant mass reconstruction. Several benchmark scenarios are considered for center of mass energies of 500 and 1000 GeV at integrated luminosity of 500$f{b}^{-1}$. Among Standard Model (SM) background processes, the main background is $e^{+}{e}^{-}\to ZZ$ followed by $Z\to \tau \tau$. This background is however, well under control. With the luminosity assumed in the analysis, striking signals are obtained beyond the reach of LHC. Such signals would allow for precise determination of masses and cross sections and alredy much lower luminosities are sufficient for discovery.

   hep-phPRD(2018)·9 citations
5. 05*

   The energy dependence of the ratio of elastic to total cross section in $pp$ and $\bar{p}p$ collisions

   V. A. Okorokov (National Research Nuclear University MEPhI)🇷🇺

   The paper presents the phenomenological analysis of the energy dependence for the ratio of elastic to total cross section in proton-proton and antiproton-proton scattering. The analytic functions based on the study of low- and high-energy experimental data for various scattering parameters provide the quantitative description of energy dependence of the ratio with statistically acceptable qualities in wide range of collision energy $\sqrt{s}\ge 3$ GeV in the case of the separate datasets for $pp$, $\bar{p}p$ collisions and at $\sqrt{s}\ge 5$ GeV for the joined experimental data ensemble. Based on the fit results the estimations are derived for the ratio of elastic to total cross section in $pp$ scattering at various $\sqrt{s}$ up to energy frontier $\sqrt{s}=10$ PeV which can be useful for present and future hadron colliders as well as for cosmic ray measurements at ultra-high energies. The indication is observed for onset of the asymptotic region at $\sqrt{s}\gtrsim 5-10$ PeV for the ratio of cross sections under consideration.

   hep-phhep-exPhys.Atom.Nucl.(2019)·4 citations
6. 06*

   Unified Origin of Axion and Monopole Dark Matter, and Solution to the Domain-wall Problem

   Ryosuke Sato🇮🇱 · Fuminobu Takahashi🇯🇵 · Masaki Yamada🇺🇸

   We propose a scenario where the spontaneous breakdown of the Peccei-Quinn symmetry leads to monopole production. Both the axion and the monopole contribute to dark matter, and the Witten effect on the axion mass is a built-in feature. In the KSVZ-type axion model, seemingly different vacua are actually connected by the hidden gauge symmetry, which makes the axionic string unstable and separate into two Alice strings. The Alice string is attached to a single domain wall due to the QCD instanton effect, solving the domain-wall problem. This is in the same spirit of the Lazarides-Shafi mechanism, although the discrete Peccei-Quinn symmetry is not embedded into the center of the original gauge symmetry. In the DFSZ-type axion model, the domain-wall problem is avoided by the Witten effect. If the Peccei-Quinn symmetry is explicitly broken by a small amount, monopoles acquire a tiny electric charge and become mini-charged dark matter. Interestingly, the quality of the Peccei-Quinn symmetry is closely tied to darkness of dark matter.

   hep-phastro-ph.COPRD(2018)·45 citations
7. 07*

   Phenomenological Analyses on Hadronic Cross-Sections at High and Asymptotic Energies

   P.V.R.G. Silva🇧🇷

   Quantum Chromodynamics constitutes the quantum field theory of the strong interaction. Despite the success of this theory in the description of several hadronic processes, the elastic scattering is still a theoretical challenge. This process is characterized by a small transferred momentum and the perturbative techniques are not applicable. Although nonperturbative results have been obtained in recent years, we still do not have a full description within QCD of the quantities related to the elastic scattering, for example, ${\sigma }_{tot}$, the $\rho$ parameter and ${\sigma }_{el}$. In this thesis, the main interest is in the energy dependence of the ratio $X={\sigma }_{el}/{\sigma }_{tot}$, ${\sigma }_{tot}$ and $\rho$. These topics are divided into three different studies. In the first topic, we develop an empirical analysis on the ratio $X$. By means of parameterizations with a small number of free parameters, we have obtained good descriptions of the data on $pp$ and $\bar{p}p$ scattering. We conclude that the asymptotic black-disk scenario is not a unique solution and the results favour a grey-disk scenario. In the second topic, we study the rise of ${\sigma }_{tot}$ with the energy through parameterizations based on the Regge-Gribov formalism and we consider two options for the leading term: a log-square and a log-raised-to-$\gamma$, with $\gamma$ a free fit parameter. We discuss two analytic methods to connect the real and imaginary parts of the amplitude: Derivative Dispersion Relations (DDR) and Asymptotic Uniqueness, which lead to different parameterizations for ${\sigma }_{tot}$ and $\rho$. The results favour the DDR method in both formal and practical contexts. In the third topic, two sub-leading terms for ${\sigma }_{tot}$, obtained in a nonperturbative QCD approach, are considered in fits to $pp$ and $\bar{p}p$ data and also in fits to data from meson-baryon and other baryon-baryon scattering.

   hep-phhep-ex0 citations
8. 08*

   Methods for a measurement of $\tau$ polarization asymmetry in the decay $Z\to \tau \tau$ at LHC and determination of the effective weak mixing angle

   Vladimir Cherepanov🇫🇷 · Wolfgang Lohmann🇩🇪

   In this paper a general method to measure the longitudinal polarization of $\tau$ lepton in the process $pp\to Z^0\to \tau \tau$ is described. The method of optimal observable allows to distinguish between the $\tau$ lepton helicity states with maximum possible sensitivity. The optimal observable for the main $\tau$ decay modes ($e/\mu \nu \nu$, $\pi \nu$, $\rho \nu$, $a_1\nu$) that can be identified by CMS or ATLAS detectors is described. The analyzing power for $\tau$ polarization can be further gained by taking into account a correlation between longitudinal spin states of ${\tau }^{+}$ and ${\tau }^{-}$. The theoretical systematic uncertainty on the $\tau$ polarization measured using the $\tau \to 3\pi \nu$ decays is estimated to be $(\Delta P_{\tau }{)}_{model}=(1.41\pm 1.37)\times 10^{-4}$. This value is approximately 50 times smaller than the best uncertainty on $\tau$ polarization measurement given by combination of all LEP results. An approach to propagate the measured $\tau$ polarization averaged over the $Z^0$ lineshape and parton density functions to the electroweak parameters is also discussed.

   hep-ph8 citations
9. 09*

   Confronting $\gamma$-rays from singlet fermionic cold dark matter with the H.E.S.S. data

   Reza Moazzemi🇮🇷

   We explore the whole parameter space of the singlet fermionic cold dark matter model with respect to constraints on, first, the relic density and second, gamma-ray lines up to 10 TeV. We investigate 44000 random sample models which comprehensively scan the parameter space for dark matter mass below 10 TeV, and compare our results with the latest experimental data from H.E.S.S., for the first time. It is showed that, except for the resonance regions, this indirect detection cannot exclude the parameter space of this model.

   hep-phhep-thEPL(2020)·1 citation
10. 10*

    Energy spectrum and the mass gap from nonperturbative quantization à la Heisenberg

    Vladimir Dzhunushaliev🇰🇿 · Vladimir Folomeev🇰🇿

    Using approximate methods of nonperturbative quantization à la Heisenberg and taking into account the interaction of gauge fields with quarks, we find regular solutions describing the following configurations: (i) a spinball consisting of two virtual quarks with opposite spins; (ii) a quantum monopole; (iii) a spinball-plus-quantum-monopole system; and (iv) a spinball-plus-quantum-dyon system. A comparison with quasi-particles obtained by lattice and phenomenological analytical calculations is carried out. All these objects (except the spinball) are embedded in a bag created by the quantum coset condensate consisting of the SU(3)/(SU(2)~$\times$~U(1)) gauge fields. The existence of these objects is due to the Meissner effect, which implies that the SU(2)~$\times$~U(1) gauge fields are expelled from the condensate. The physical interpretation of these solutions is proposed in two different forms: (i) an approximate glueball model; and (ii) quantum fluctuations in the coset condensate of the nonperturbative vacuum or in a quark-gluon plasma. For the spinball and the spinball-plus-quantum-monopole configuration, we obtain energy spectra, in which mass gaps are present. The process of deconfinement is discussed qualitatively. It is shown that the quantum chromodynamics constant ${\Lambda }_{\text{QCD}}$ appears in the nonperturbative quantization à la Heisenberg as some constant controlling the correlation length of quantum fields in a spacelike direction.

    hep-phhep-th1 citation
11. 11*

    The $D^{\ast }{D}^{\ast }\bar{D}$ and $D^{\ast }{D}^{\ast }{\bar{D}}^{\ast }$ Three-Body Systems

    Manuel Pavon Valderrama🇨🇳

    The hidden charm $X(3872)$ resonance is usually thought to be a $D^{\ast 0}{\bar{D}}^0$ meson-antimeson molecule with quantum numbers $J^{PC}=1^{++}$. If this is the case, there is the possibility that there might be three body bound states with two charmed mesons and a charmed antimeson. Here we argue that the theoretical existence of this type of three body molecules is expected from heavy quark spin symmetry. If applied to the two body sector, this symmetry implies that the interaction of the $D^{\ast 0}{\bar{D}}^{\ast 0}$ meson-antimeson pair in the $J^{PC}=2^{++}$ channel is the same as in the $J^{PC}=1^{++}$ $D^{\ast 0}{\bar{D}}^0$ case. From this we can infer that the $J^P=3^{-}$ $D^{\ast 0}{D}^{\ast 0}{\bar{D}}^{\ast 0}$ molecule will be able to display the Efimov effect if the scattering length of the $2^{++}$ channel is close enough to the unitary limit. Heavy quark spin symmetry also indicates that the $J^P=2^{-}$ $D^{\ast 0}{D}^{\ast 0}{\bar{D}}^0$ molecule is analogous to the $J^P=3^{-}$ $D^{\ast 0}{D}^{\ast 0}{\bar{D}}^{\ast 0}$ one. That is, it can also have a geometric spectrum. If we consider these triply heavy trimers in the isospin symmetric limit, the Efimov effect disappears and we can in principle predict the fundamental state of the $2^{-}$ $D^{\ast }{D}^{\ast }\bar{D}$ and $3^{-}$ $D^{\ast }{D}^{\ast }{\bar{D}}^{\ast }$ systems. The same applies to the $B^{\ast }{B}^{\ast }{\bar{B}}^{\ast }$ system: if the $Z_b(10650)$ is an isovector $B^{\ast }{\bar{B}}^{\ast }$ molecule then the $0^{-}$ isodoublet and the $1^{-}$, $2^{-}$ isoquartet $B^{\ast }{B}^{\ast }{\bar{B}}^{\ast }$ trimers might bind, but do not display Efimov physics. Finally from heavy flavour symmetry it can be argued that scattering in the $BD$ two-body system might be resonant. This would in turn imply the possibility of Efimov physics in the $BBD$ three body system.

    hep-phhep-exnucl-thPRD(2018)·18 citations
12. 12*

    Looking for the gluon condensation signature in proton using the Earth limb gamma-ray spectra

    Lei Feng🇨🇳 · Jianhong Ruan🇨🇳 · Fan Wang🇨🇳 · Wei Zhu🇨🇳

    A new type of gamma ray spectrum is predicted in a general hadronic framework if considering the gluon condensation effects in proton. The result presents the power-law with a sharp break in the gamma ray spectra at the TeV-band. We suggest to probe this GC-signature in the Earth limb gamma-ray spectra using the DArk Matter Particle Explorer and the CALorimetric Electron Telescope on orbit.

    hep-phastro-ph.HEhep-exnlin.CDApJ(2018)·15 citations
13. 13*

    Resurrecting Minimal Yukawa Sector of SUSY SO(10)

    K.S. Babu🇺🇸 · Borut Bajc🇸🇮 · Shaikh Saad🇺🇸

    Supersymmetric $SO(10)$ models with Yukawa coupling matrices involving only a $10_H$ and a ${\overline{126}}_H$ of Higgs fields can lead to a predictive and consistent scenario for fermion masses and mixings, including the neutrino sector. However, when coupled minimally to a symmetry breaking sector that includes a $210_H$ and a $126_H$, these models lead either to an unacceptably small neutrino mass scale, or to non-perturbative values of the gauge couplings. Here we show that with the addition of a $54_H$ to the symmetry breaking sector, the successful predictions of these models for fermion masses and mixings can be maintained. The $54_H$ enables a reduction of the $B-L$ symmetry breaking scale to an intermediate value of order $10^{12}$ GeV, consistent with the observed neutrino mass spectrum, while preserving perturbative gauge coupling unification. We obtain an excellent fit to all fermion masses and mixings in this framework. We analyze carefully the prediction of the model for CP violation in neutrino oscillations. Consistency with proton lifetime, however, requires a mini-split SUSY spectrum with the squarks and sleptons having masses of order 100 TeV, accompanied by TeV scale gauginos and Higgsinos. Such a spectrum may arise from pure gravity mediation, which would predict the partial lifetime for the decay $p\to \overline{\nu }{K}^{+}$ to be an order of magnitude above the current experimental limit.

    hep-phJHEP(2018)·43 citations
14. 14*

    Electroweak baryogenesis via chiral gravitational waves

    H. Abedi🇮🇷 · M. Ahmadvand🇮🇷 · S.S. Gousheh🇮🇷

    We propose a new mechanism for electroweak baryogenesis based on gravitational waves generated by helical magnetic fields that are present during a first order electroweak phase transition. We generate a net lepton number through the gravitational chiral anomaly which appears due to the chiral gravitational waves produced by these magnetic fields. The observed value of baryon asymmetry can be obtained in our mechanism within parameter space of scenarios with an inverse cascade evolution for magnetic fields which can also be candidates for large-scale magnetic fields.

    hep-phgr-qchep-thPLB(2018)·11 citations
15. 15*

    An Asymmetric TBM Texture

    Moinul Hossain Rahat🇺🇸 · Pierre Ramond🇺🇸 · Bin Xu🇺🇸

    We construct a texture where the Seesaw matrix is diagonalized by the TriBiMaximal (TBM) matrix with a phase. All CKM and PMNS angles are within their pdg values, and the mass relations of quarks and charged leptons extrapolated to GUT scale are satisfied, including the Gatto relation. The novel ingredient is the asymmetry of the down-quark and charged lepton Yukawa matrices. Explaining the reactor angle requires a $\text{require}cancel\cancel{CP}$ phase in the TBM matrix, resulting in the Jarlskog-Greenberg invariant at $|J|=0.028$, albeit with an undetermined sign. While $SO(10)$ restrains the right-handed neutrino Majorana matrix, the neutrino masses are left undetermined.

    hep-phhep-thPRD(2018)·59 citations
16. 16*

    Deep learning for the R-parity violating supersymmetry searches at the LHC

    Jun Guo🇨🇳 · Jinmian Li🇰🇷 · Tianjun Li🇨🇳 · Fangzhou Xu🇨🇳 · Wenxing Zhang🇨🇳

    Supersymmetry with hadronic R-parity violation in which the lightest neutralino decays into three quarks is still weakly constrained. This work aims to further improve the current search for this scenario by the boosted decision tree method with additional information from jet substructure. In particular, we find a deep neural network turns out to perform well in characterizing the neutralino jet substructure. We first construct a Convolutional Neutral Network (CNN) which is capable of tagging the neutralino jet in any signal process by using the idea of jet image. When applied to pure jet samples, such a CNN outperforms the N-subjettiness variable by a factor of a few in tagging efficiency. Moreover, we find the method, which combines the CNN output and jet invariant mass, can perform better and is applicable to a wider range of neutralino mass than the CNN alone. Finally, the ATLAS search for the signal of gluino pair production with subsequent decay $\tilde{g}\to qq{\tilde{\chi }}_1^0(\to qqq)$ is recasted as an application. In contrast to the pure sample, the heavy contamination among jets in this complex final state renders the discriminating powers of the CNN and N-subjettiness similar. By analyzing the jets substructure in events which pass the ATLAS cuts with our CNN method, the exclusion limit on gluino mass can be pushed up by $\sim 200$ GeV for neutralino mass $\sim 100$ GeV.

    hep-phhep-exPRD(2018)·26 citations
17. 17*

    Electroexcitation of nucleon resonances in a light-front relativistic quark model

    I. G. Aznauryan🇦🇲 · V. D. Burkert🇺🇸

    We report the predictions for the 3q core contributions to the electroexcitation of the resonances Delta(1232)3/2+, N(1440)1/2+, N(1520)3/2-, N(1535)1/2-, and N(1675)5/2- on the proton obtained in the light-front relativistic quark model (LF RQM). For these states, experimental data on the electroexcitation transition amplitudes allow us to make comparison between the experiment and LF RQM predictions in wide range of Q2 and also to quantify the expected meson-baryon contributions as a function of Q2.

    hep-phnucl-thFew Body Syst.(2018)·15 citations
18. 18*

    Tomography by neutrino pair beam

    Takehiko Asaka🇯🇵 · Hisashi Okui🇯🇵 · Minoru Tanaka🇯🇵 · Motohiko Yoshimura🇯🇵

    We consider tomography of the Earth's interior using the neutrino pair beam which has recently been proposed. The beam produces a large amount of neutrino and antineutrino pairs from the circulating partially stripped ions and provides the possibility to measure precisely the energy spectrum of neutrino oscillation probability together with a sufficiently large detector. It is shown that the pair beam gives a better sensitivity to probe the Earth's crust compared with the neutrino sources at present. In addition we present a method to reconstruct a matter density profile by means of the analytic formula of the oscillation probability in which the matter effect is included perturbatively to the second order.

    hep-phhep-exPLB(2018)·4 citations
19. 19*

    Role of newly discovered ${\Xi }_b(6227{)}^{-}$ for constructing excited bottom baryon family

    Bing Chen🇨🇳 · Ke-Wei Wei🇨🇳 · Xiang Liu🇨🇳 · Ailin Zhang🇨🇳

    Selecting the newly observed ${\Xi }_b(6227{)}^{-}$ by LHCb as a study example, we decode its inner structure by giving the mass spectrum analysis and the investigation of its two-body strong decay behaviors. Our result indicates that the ${\Xi }_b(6227{)}^{-}$ is a good candidate of the $P$-wave ${\Xi }_b^{\prime }$ state with $J^P=3/2^{-}$ or $5/2^{-}$. In addition, we further provide the information of the properties of the partners of the ${\Xi }_b(6227{)}^{-}$. These predicted states include three $2S$ states and the remaining $1P$ states in the bottom-strange baryon family. The calculated sizable Okubo-Zweig-Iizuka$-$allowed decay widths of these partners show that the experimental search for them becomes possible via LHCb. We have a reason to believe that the present study can be treated as a start point for constructing the highly excited bottom baryon spectroscopy.

    hep-phhep-exPRD(2018)·63 citations
20. 20*

    Cornering sgluons with four-top-quark events

    Luc Darmé🇵🇱 · Benjamin Fuks🇫🇷 · Mark Goodsell🇫🇷

    The existence of colour-octet scalar states, often dubbed sgluons, is predicted in many extensions of the Standard Model of particle physics, such as supersymmetric realisations featuring Dirac gauginos. Such states have a large pair-production rate at hadron colliders and mainly decay into pairs of jets and top quarks. Consequently, they represent a primary target for experimental searches for new resonances in the multijet and multitop channels at the Large Hadron Collider. Adopting a phenomenologically-motivated simplified model, we reinterpret the results of a recent experimental search for the four-top-quark Standard Model signal, from which we constrain the sgluon mass to be larger than about 1.06 TeV. We additionally consider how modifications of the existing four-top-quark studies could enhance our ability to unravel the presence of scalar octets in data.

    hep-phhep-exPLB(2018)·57 citations
21. 21*

    Sequential Coalescence with Charm Conservation in High Energy Nuclear Collisions

    Jiaxing Zhao🇨🇳 · Shuzhe Shi🇺🇸 · Nu Xu🇨🇳 · Pengfei Zhuang🇨🇳

    Heavy quarks are initially produced in nuclear collisions and the number is conserved during the evolution of the system. We establish a sequential coalescence model with charm conservation and apply it to charmed hadron production at RHIC and LHC energies. The charm conservation enhances the earlier formed hadrons and reduces the later formed ones, which leads to a $D_s/D^0$ enhancement and a ${\Lambda }_c/D^0$ suppression. The mass dependence of the sequential hadron formation provides us a new tool for studying the quark-gluon plasma hadronization in high energy nuclear collisions.

    hep-phnucl-th46 citations
22. 22*

    Walking Technicolor in the light of $Z^{\prime }$ searches at the LHC

    Alexander Belyaev🇬🇧 · Azaria Coupe🇬🇧 · Mads Frandsen🇩🇰 · Emmanuel Olaiya🇬🇧 · Claire Shepherd-Themistocleous🇬🇧

    We investigate the potential of the Large Hadron Collider (LHC) to probe one of the most compelling Beyond the Standard Model (BSM) frameworks --- Walking Technicolor (WTC), involving strong dynamics and having a slowly running (walking) new strong coupling. For this purpose we use recent LHC Run2 data to explore the full parameter space of the minimal WTC model using dilepton signatures from heavy neutral $Z^{\prime }$ and $Z^{\prime \prime }$ resonances predicted by the model. This signature is the most promising one for discovery of WTC at the LHC for the low-intermediate values of the $\tilde{g}$ coupling -- one of the principle parameters of WTC. We have demonstrated complementarity of the dilepton signals from both resonances, have established the most up-to-date limit on the WTC parameter space, and provided projections for the the LHC potential to probe the WTC parameter space at higher future luminosities and upgraded energy. We have explored the whole four-dimensional parameter space of the model and have found the most conservative limit on the WTC scale $M_A$ above 3 TeV for the low values of $\tilde{g}$ which is significantly higher than previous limits established by the LHC collaborations.

    hep-phPRD(2019)·6 citations
23. 23*

    Two-photon exchange: myth and history

    Egle Tomasi-Gustafsson🇫🇷 · Simone Pacetti🇮🇹

    After recalling the arguments for possible excess of two-photon contribution over $\alpha$-counting, model independent statements about the consequences on the observables will be given. The relevant experimental data are discussed: (polarized and unpolarized) electron and positron elastic scattering on the proton, as well as annihilation data. A reanalysis of unpolarized electron-proton elastic scattering data is presented in terms of the electric to magnetic form factor squared ratio. This observable is in principle more robust against experimental correlations and global normalizations. The present analysis shows indeed that it is a useful quantity that contains reliable and coherent information. The comparison with the ratio extracted from the measurement of the longitudinal to transverse polarization of the recoil proton in polarized electron-proton scattering shows that the results are compatible. These results bring a decisive piece of information in the controversy on the deviation of the proton form factors from the dipole dependence.

    hep-phnucl-thFew Body Syst.(2018)·7 citations
24. 24*

    Weak decays of doubly heavy baryons: the $1/2\to 3/2$ case

    Zhen-Xing Zhao🇨🇳

    As a continuation of our previous works, we investigate the weak decays of doubly heavy baryons into a spin-$3/2$ singly or doubly heavy baryon. Light-front approach is adopted to handle the dynamics in the transitions, in which the two spectator quarks are approximated as a diquark. Results for form factors are then used to calculate decay widths of semi-leptonic and nonleptonic processes. The flavor SU(3) symmetry and symmetry breaking effects in semi-leptonic decays modes are explored, and we point out that in charm sector, there are sizable symmetry breaking effects. For nonleptonic decay modes, we study only the factorizable channels induced by the external W-emission. We find that branching fractions for most 1/2 to 3/2 transitions are approximately one order of magnitude smaller than the corresponding ones for the 1/2 to 1/2 transitions. Parametric uncertainties are also investigated in detail. This work, together with our previous works, are beneficial to the experimental studies of doubly heavy baryons at LHC and other experiments.

    hep-phhep-exEPJC(2018)·74 citations
25. 25*

    Exploring the generalized loosely bound Skyrme model

    Sven Bjarke Gudnason🇯🇵

    The Skyrme model is extended with a sextic derivative term - called the BPS-Skyrme term - and a repulsive potential term - called the loosely bound potential. A large part of the model's parameter space is studied for the 4-Skyrmion which corresponds to the Helium-4 nucleus and emphasis is put on preserving as much of the platonic symmetries as possible whilst reducing the binding energies. We reach classical binding energies for Helium-4 as low as 0.2%, while retaining the cubic symmetry of the 4-Skyrmion, and after taking into account the quantum mass correction to the nucleon due to spin/isospin quantization, we get total binding energies as low as 3.6% - still with the cubic symmetry intact.

    hep-phnucl-thPRD(2018)·22 citations
26. 26*

    Decay rates $f_1(1285)\to {\rho }^0{\pi }^{+}{\pi }^{-}$ and $a_1(1260)\to \omega {\pi }^{+}{\pi }^{-}$ in the Nambu -- Jona-Lasinio model

    A. A. Osipov🇷🇺 · A. A. Pivovarov🇷🇺 · M. K. Volkov🇷🇺

    The anomalous decays $f_1(1285)\to {\rho }^0{\pi }^{+}{\pi }^{-}$ and $a_1(1260)\to \omega {\pi }^{+}{\pi }^{-}$ violating natural parity for vectors and axial-vectors are studied in the framework of the Nambu -- Jona-Lasinio model. We consider the Lagrangian with $U(2{)}_L\times U(2{)}_R$ chiral symmetric four quark interactions. The theory is bosonized and corresponding effective meson vertices are obtained in the leading order of $1/N_c$ and derivative expansions. The uncertainties related with the surface terms of anomalous quark triangle diagrams are fixed by the corresponding symmetry requirements. We make a numerical estimate of the decay widths $\Gamma (f_1(1285)\to {\rho }^0{\pi }^{+}{\pi }^{-})=2.78\text{mbox}MeV$ and $\Gamma (a_1(1260)\to \omega {\pi }^{+}{\pi }^{-})=87\text{mbox}keV$. Our result on the $f_1(1285)\to {\rho }^0{\pi }^{+}{\pi }^{-}$ decay rate is in a good agreement with experiment. It is shown that a strong suppression of the $a_1(1260)\to \omega \pi \pi$ decay is a direct consequence of destructive interference between box and triangle anomalies.

    hep-phPRD(2018)·7 citations
27. 27*

    Operator Product Expansion in QCD Is Not Consistent With Quantum Field Theory For Gluon Distribution Function

    Gouranga C Nayak🇺🇸

    Since the operator product expansion (OPE) is applicable at short distance the OPE in QCD does not solve the long distance confinement problem involving hadron in QCD where the non-perturbative QCD is applicable. In this paper we show that the gauge invariant definition of the non-perturbative gluon distribution function inside the hadron consistent with the operator product expansion (OPE) in QCD at high energy colliders is not consistent with the gauge invariant definition of the non-perturbative gluon distribution function in the quantum field theory.

    hep-phnucl-th0 citations
28. 28*

    New spectrum of negative-parity doubly charmed baryons: Possibility of two quasistable states

    Mao-Jun Yan🇨🇳 · Xiao-Hai Liu🇩🇪 · Sergi Gonzàlez-Solís🇨🇳 · Feng-Kun Guo🇨🇳 · Christoph Hanhart🇩🇪 · Ulf-G. Meißner🇩🇪 · Bing-Song Zou🇨🇳

    The discovery of ${\Xi }_{cc}^{++}$ by the LHCb Collaboration triggers predictions of more doubly charmed baryons. By taking into account both the $P$-wave excitations between the two charm quarks and the scattering of light pseudoscalar mesons off the ground state doubly charmed baryons, a set of negative-parity spin-1/2 doubly charmed baryons are predicted already from a unitarized version of leading order chiral perturbation theory. Moreover, employing heavy antiquark-diquark symmetry the relevant low-energy constants in the next-to-leading order are connected with those describing light pseudoscalar mesons scattering off charmed mesons, which have been well determined from lattice calculations and experimental data. Our calculations result in a spectrum richer than that of heavy mesons. We find two very narrow $J^P=1/2^{-}$ ${\Omega }_{cc}^P$, which very likely decay into ${\Omega }_{cc}{\pi }^0$ breaking isospin symmetry. In the isospin-1/2 ${\Xi }_{cc}^P$ sector, three states are predicted to exist below 4.2~GeV with the lowest one being narrow and the other two rather broad. We suggest to search for the ${\Xi }_{cc}^P$ states in the ${\Xi }_{cc}^{++}{\pi }^{-}$ mode. Searching for them and their analogues are helpful to establish the hadron spectrum.

    hep-phhep-exhep-latnucl-ex+1PRD(2018)·41 citations
29. 29*

    Unified atmospheric neutrino passing fractions for large-scale neutrino telescopes

    Carlos A. Argüelles🇺🇸 · Sergio Palomares-Ruiz🇪🇸 · Austin Schneider🇺🇸 · Logan Wille🇺🇸 · Tianlu Yuan🇺🇸

    The atmospheric neutrino passing fraction, or self-veto, is defined as the probability for an atmospheric neutrino not to be accompanied by a detectable muon from the same cosmic-ray air shower. Building upon previous work, we propose a redefinition of the passing fractions by unifying the treatment for muon and electron neutrinos. Several approximations have also been removed. This enables performing detailed estimations of the uncertainties in the passing fractions from several inputs: muon losses, cosmic-ray spectrum, hadronic-interaction models and atmosphere-density profiles. We also study the passing fractions under variations of the detector configuration: depth, surrounding medium and muon veto trigger probability. The calculation exhibits excellent agreement with passing fractions obtained from Monte Carlo simulations. Finally, we provide a general software framework to implement this veto technique for all large-scale neutrino observatories.

    hep-phastro-ph.HEhep-exJCAP(2018)·65 citations
30. 30*

    Exploring the intrinsic Lorentz-violating parameters at DUNE

    Gabriela Barenboim🇪🇸 · Mehedi Masud🇪🇸 · Christoph A. Ternes🇪🇸 · Mariam Tórtola🇪🇸

    Neutrinos can push our search for new physics to a whole new level. What makes them so hard to be detected, what allows them to travel humongous distances without being stopped or deflected allows to amplify Planck suppressed effects (or effects of comparable size) to the level we can measure or bound in DUNE. In this work we analyse the sensitivity of DUNE to CPT and Lorentz--violating interactions in a framework that allows a straightforward extrapolation of the bounds obtained to any phenomenological modification of the dispersion relation of neutrinos.

    hep-phhep-exPLB(2019)·46 citations
31. 31*

    The Return of Kaon Flavour Physics

    Andrzej J. Buras🇩🇪

    Kaon flavour physics has played in the 1960s and 1970s a very important role in the construction of the Standard Model (SM) and in the 1980s and 1990s in SM tests with the help of CP violation in $K_L\to \pi \pi$ decays represented by ${\epsilon }_K$ and the ratio ${\epsilon }^{\prime }/\epsilon$. In this millennium this role has been taken over by $B_{s,d}$ and $D$ mesons. However there is no doubt that in the coming years we will witness the return of kaon flavour physics with the highlights being the measurements of the theoretically clean branching ratios for the rare decays $K^{+}\to {\pi }^{+}\nu \bar{\nu }$ and $K_L\to {\pi }^0\nu \bar{\nu }$ and the improved SM predictions for the ratio ${\epsilon }^{\prime }/\epsilon$, for ${\epsilon }_K$ and the $K^0-{\bar{K}}^0$ mixing mass difference $\Delta M_K$. Theoretical progress on the decays $K_{L,S}\to {\mu }^{+}{\mu }^{-}$ and $K_L\to {\pi }^0{\ell }^{+}{\ell }^{-}$ is also expected. They all are very sensitive to new physics (NP) contributions and the correlations between them should help us to identify new dynamics at very short distance scales. These studies will be enriched when theory on the $K\to \pi \pi$ isospin amplitudes $\mathrm{Re}{A}_0$ and $\mathrm{Re}{A}_2$ improves. This talk summarizes several aspects of this exciting field. In particular we emphasize the role of the Dual QCD approach in getting the insight into the numerical Lattice QCD results on $K^0-{\bar{K}}^0$ mixing and $K\to \pi \pi$ decays.

    hep-phhep-exhep-latActa Phys.Polon.B(2018)·28 citations
32. 32*

    Effect of Fermionic Operators on the Gauge Legacy of the LHC Run I

    Alexandre Alves🇧🇷 · N. Rosa-Agostinho🇪🇸 · Oscar J. P. Éboli🇧🇷 · M.C.Gonzalez--Garcia🇪🇸

    We revisit the extraction of the triple electroweak gauge boson couplings from the Large Hadron Collider Run I data on the $W^{+}{W}^{-}$ and $W^{\pm }Z$ productions when the analysis also contains additional operators that modify the couplings of the gauge bosons to light quarks and the gauge boson self-energies. We work in the framework of effective Lagrangians where we consider dimension-six operators and perform a global fit to consistently take into account the bounds on these additional operators originating from the electroweak precision data. We show that the constraints on the Wilson coefficients $f_B/{\Lambda }^2$ and $f_W/{\Lambda }^2$ are modified when we include the additional operators while the limits on $f_{WWW}/{\Lambda }^2$ remain unchanged.

    hep-phPRD(2018)·28 citations
33. 33*

    Aspects of Track-Assisted Mass

    Benjamin T. Elder🇺🇸 · Jesse Thaler🇺🇸

    Track-assisted mass is a proxy for jet mass that only uses direction information from charged particles, allowing it to be measured at the Large Hadron Collider with very fine angular resolution. In this paper, we introduce a generalization of track-assisted mass and analyze its performance in both parton shower generators and resummed calculations. For the original track-assisted mass, the track-only mass is rescaled by the charged energy fraction of the jet. In our generalization, the rescaling factor includes both per-jet and ensemble-averaged information, facilitating a closer correspondence to ordinary jet mass. Using the track function formalism in electron-positron collisions, we calculate the spectrum of generalized track-assisted mass to next-to-leading-logarithmic order with leading-order matching. These resummed calculations provide theoretical insight into the close correspondence between track-assisted mass and ordinary jet mass. With the growing importance of jet grooming algorithms, we also calculate track-assisted mass on soft-drop groomed jets.

    hep-phhep-exJHEP(2019)·13 citations
34. 34*

    Hadroproduction of neutral Kstar-mesons up to LHC energies

    G.H. Arakelyan🇦🇲 · C. Merino🇪🇸 · Yu.M. Shabelski🇷🇺

    We consider the experimental data on neutral Kstar-meson production on nucleon and nuclear targets. The Quark-Gluon String Model quantitatively describes the inclusive density in the midrapidity region, as well as the initial energy and A dependences of the produced Kstar-mesons.

    hep-phEPJA(2019)·2 citations
35. 35*

    Search for a lighter Higgs Boson in the Next-to-Minimal Supersymmetric Standard Model

    Junquan Tao🇨🇳 · M. Aamir Shahzad🇨🇳 · Sijing Zhang🇨🇳 · Chu Wang🇨🇳 · Yuqiao Shen🇨🇳 · Guoming Chen🇨🇳 · Hesheng Chen🇨🇳 · S. Gascon-Shotkin🇫🇷 · M. Lethuillier🇫🇷 · L. Finco🇫🇷 · C. Camen🇫🇷

    After the discovery of the Higgs boson with mass at approximately 125 $GeV$ at the LHC, many studies both from the theoretical and experimental sides have been performed to search for a new Higgs Boson lighter than the 125 $GeV$ Higgs boson. We explore the possibility of constraining a lighter neutral scalar Higgs boson $h_1$ and a lighter pseudo-scalar Higgs boson $a_1$ in the Next-to-Minimal Supersymmetric Standard Model by restricting the next-to-lightest scalar Higgs boson $h_2$ to be the LHC observed Higgs boson after the phenomenological constraints and the constraints from experimental measurements. Such lighter particles are not yet completely excluded by the latest results of the search for a lighter Higgs boson with the diphoton decay channel from LHC data. Our results show that for a lighter scalar Higgs boson some new constraints on the Next-to-Minimal Supersymmetric Standard Model could be obtained at the LHC if such a search is performed by the experimental collaborations with more data. The discovery potential of other interesting decay channels of such a lighter neutral scalar and a pseudo-scalar particle are also discussed.

    hep-phCPC(2018)·15 citations
36. 36*

    Photoproduction of vector mesons in proton-proton ultraperipheral collisions at the CERN Large Hadron Collider

    Ya-Ping Xie🇨🇳 · Xurong Chen🇨🇳

    Photoproduction of vector mesons are computed in dipole model in proton-proton ultraperipheral collisions(UPCs) at the CERN Large Hadron Collider (LHC). The dipole model framework is employed in the calculations of vector mesons production in diffractive processes. Parameters of the bCGC model are refitted with the latest inclusive deep inelastic scattering experimental data. Employing the bCGC model and Boosted Gaussian light-cone wave function for vector mesons, we obtain prediction of rapidity distributions of $J/\psi$ and $\psi (2s)$ mesons in proton-proton ultraperipheral collisions at the LHC. The predictions give a good description to the experimental data of LHCb. Predictions of $\varphi$ and $\omega$ mesons are also evaluated in this paper.

    hep-phInt.J.Mod.Phys.A(2018)·6 citations
37. 37*

    Chiral magnetohydrodynamic turbulence in core-collapse supernovae

    Youhei Masada🇯🇵 · Kei Kotake🇯🇵 · Tomoya Takiwaki🇯🇵 · Naoki Yamamoto🇯🇵

    Macroscopic evolution of relativistic charged matter with chirality imbalance is described by the chiral magnetohydrodynamics (chiral MHD). One such astrophysical system is high-density lepton matter in core-collapse supernovae where the chirality imbalance of leptons is generated by the parity-violating weak processes. After developing the chiral MHD equations for this system, we perform numerical simulations for the real-time evolutions of magnetic and flow fields, and study the properties of the chiral MHD turbulence. In particular, we observe the inverse cascade of the magnetic energy and the fluid kinetic energy. Our results suggest that the chiral effects that have been neglected so far can reverse the turbulent cascade direction from direct to inverse cascade, which would impact the magnetohydrodynamics evolution in the supernova core toward explosion.

    ↳ astro-ph.HEhep-phnucl-thPRD(2018)·50 citations
38. 38*

    Nucleon charges with dynamical overlap fermions

    Nodoka Yamanaka🇫🇷 · Shoji Hashimoto🇯🇵 · Takashi Kaneko🇯🇵 · Hiroshi Ohki (JLQCD Collaboration)🇺🇸

    We calculate the scalar and tensor charges of the nucleon in 2+1-flavor lattice QCD, for which the systematics of the renormalization of the disconnected diagram is well controlled. Numerical simulations are performed at a single lattice spacing a = 0.11 fm. We simulate four pion masses, which cover a range of $m_{\pi }\sim$ 290 - 540 MeV, and a single strange quark mass close to its physical value. The statistical accuracy is improved by employing the so-called low-mode averaging technique and the truncated solver method. We study up, down, and strange quark contributions to the nucleon charges by calculating disconnected diagrams using the all-to-all quark propagator. Chiral symmetry is exactly preserved by using the overlap quark action to avoid operator mixing among different flavors, which complicates the renormalization of scalar and tensor matrix elements and leads to possibly large contamination to the small strange quark contributions. We also study the nucleon axial charge with contribution from the disconnected diagram. Our results are in reasonable agreement with experiments and previous lattice studies.

    ↳ hep-lathep-exhep-phnucl-thPRD(2018)·122 citations
39. 39*

    Implications on cosmic ray injection and propagation parameters from Voyager/ACE/AMS-02 nucleus data

    Qiang Yuan (PMO, USTC)🇨🇳

    We study the propagation and injection models of cosmic rays using the latest measurements of the Boron-to-Carbon ratio and fluxes of protons, Helium, Carbon, and Oxygen nuclei by the Alpha Magnetic Spectrometer and the Advanced Composition Explorer at top of the Earth, and the Voyager spacecraft outside the heliosphere. The ACE data during the same time interval of the AMS-02 data are extracted to minimize the complexity of the solar modulation effect. We find that the cosmic ray nucleus data favor a modified version of the diffusion-reacceleration scenario of the propagation. The diffusion coefficient is, however, required to increase moderately with decreasing rigidity at low energies, which has interesting implications on the particle and plasma interaction in the Milky Way. We further find that the low rigidity ($<$ a few GV) injection spectra are different for different compositions. The injection spectra are softer for lighter nuclei. These results are expected to be helpful in understanding the acceleration process of cosmic rays.

    ↳ astro-ph.HEhep-phSCPMA(2019)·42 citations
40. 40*

    Investigating Dark Matter and MOND Models with Galactic Rotation Curve Data

    Mads T. Frandsen🇩🇰 · Jonas Petersen🇩🇰

    We study geometries of galactic rotation curves from Dark Matter (DM) and Modified Newtonian Dynamics (MOND) models in $(g_{\mathrm{bar}},g_{\mathrm{tot}})$-space ($g2$-space) where $g_{\mathrm{tot}}$ is the total centripetal acceleration of matter in the galaxies and $g_{\mathrm{bar}}$ is that due to the baryonic (visible) matter assuming Newtonian gravity. The $g2$-space geometries of the models and data from the SPARC database are classified and compared in a rescaled $\hat{g}2$-space that reduces systematic uncertainties on galaxy distance, inclination angle and variations in mass to light ratios. We find that MOND modified inertia models, frequently used to fit rotation curve data, are disfavoured at more than 5$\sigma$ independent of model details. The Bekenstein-Milgrom formulation of MOND modified gravity compares better with data in the analytic approximation we use. However a quantitative comparison with data is beyond the scope of the paper due to this approximation. NFW DM profiles only agree with a minority of galactic rotation curves. Improved measurements of rotation curves, in particular at radii below the maximum of the total and the baryonic accelerations of the curves are very important in discriminating models aiming to explain the missing mass problem on galactic scales.

    ↳ astro-ph.GAhep-ph17 citations
41. 41*

    Weak decay of magnetized pions

    Gunnar S. Bali🇩🇪 · Bastian B. Brandt🇩🇪 · Gergely Endrodi🇩🇪 · Benjamin Glaessle🇩🇪

    The leptonic decay of charged pions is investigated in the presence of background magnetic fields. In this situation Lorentz symmetry is broken and new fundamental decay constants need to be introduced, associated with the decay via the vector part of the electroweak current. We calculate the magnetic field-dependence of both the usual and a new decay constant non-perturbatively on the lattice. We employ both Wilson and staggered quarks and extrapolate the results to the continuum limit. With this non-perturbative input we calculate the tree-level electroweak amplitude for the full decay rate in strong magnetic fields. We find that the muonic decay of the charged pion is enhanced drastically by the magnetic field. We comment on possible astrophysical implications.

    ↳ hep-lathep-phnucl-thPRL(2018)·46 citations
42. 42*

    Image-processing the topological charge density in the CP(N-1) model

    Yuya Abe🇯🇵 · Kenji Fukushima🇯🇵 · Yoshimasa Hidaka🇯🇵 · Hiroaki Matsueda🇯🇵 · Koichi Murase🇯🇵 · Shoichi Sasaki🇯🇵

    We study the topological charge density distribution using the two-dimensional $C{P}^{N-1}$ model. We numerically compute not only the topological susceptibility, which is a spatially global quantity to probe topological properties of the whole system, but also the topological charge correlator with finite momentum. We perform Fourier power spectrum analysis for the topological charge density for various values of the inverse temperature $\beta$. We propose to utilize the Fourier entropy as a convenient measure to characterize spatial distribution patterns and demonstrate that the Fourier entropy exhibits nontrivial temperature dependence. We also consider the snapshot entropy defined with the singular value decomposition, which also turns out to behave nonmonotonically with the temperature. We give a possible interpretation suggested from the strong-coupling analysis.

    ↳ hep-lathep-phPTEP(2020)·10 citations
43. 43*

    Galaxy rotation curves in modified gravity models

    Álefe O.F. de Almeida🇧🇷 · Luca Amendola🇩🇪 · Viviana Niro🇩🇪

    In this work, we investigate the possibility that the galaxy rotation curves can be explained in the framework of modified gravity models that introduce a Yukawa term in the gravitational potential. We include dark matter and assume that the fifth-force couples differently to dark matter and to baryons. We aim at constraining the modified gravity parameters $\beta$ and $\lambda$, that is, the strength and the range of the Yukawa fifth force, respectively, using a set of 40 galaxy rotation curves data from the SPARC catalogue. We include baryonic gas, disk and bulge components, along with a NFW halo of dark matter. Each galaxy rotation curve is modeled with three free parameters, beside the two global Yukawa parameter. We find that the inclusion of the Yukawa term improves the ${\chi }^2$ from $680.75$ to $536.23$ for $655$ degrees of freedom. As global best-fit we obtain $\beta =0.34\pm 0.04$ and $\lambda =5.61\pm 0.91$kpc and a dark matter content on average 20\% smaller than without the Yukawa term. The Bayesian evidence in favor of a NFW profile plus Yukawa term is higher than 8$\sigma$ with respect to the standard gravity parametrization.

    ↳ astro-ph.GAastro-ph.COgr-qchep-phJCAP(2018)·45 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.