Tue·Sep 4, 2018Tuesday·September 4, 2018

1. 01*

   Theoretical perspective for the future experiments on parton densities

   S. Kumano (KEK/J-PARC)🇯🇵

   I explain the current status of parton-distribution-function (PDF) studies and future experimental prospects on their determinations. First, unpolarized PDFs of the nucleon are introduced as a field of precision QCD physics including higher-order ${\alpha }_s$ corrections. Second, nuclear PDFs and polarized nucleonic PDFs are discussed. Third, the determination of fragmentation functions is explained. Forth, the three-dimensional (3D) structure functions are discussed in connection with the origin of the nucleon spin and gravitational form factors of hadrons. By the 3D structure functions, gravitational sources and the origin of nucleon mass could be clarified in the microscopic level of quarks and gluons. Furthermore, 3D structure studies of hadrons could be used for clarifying internal structure of exotic hadron candidates, nuclear composition of ultra-high-energy cosmic rays, and color-entanglement phenomena. The PDF field will be developed further along with progress in other fields of science.

   hep-phhep-exhep-latnucl-ex+1PoS(2018)·3 citations
2. 02*

   Higgs Cosmology and Dark Matter

   Ian G. Moss🇬🇧 · Ruth Gregory🇬🇧

   Higgs vacuum stability has important consequences for cosmology. In particular, we argue that if the Higgs vacuum is metastable, then the dark matter cannot contain a single black hole of mass less than $10^{15}\mathrm{g}$ in our entire past light cone. In addition to being the destroyer microscopic black holes, it may be possible that Higgs vacuum decay is a source of primordial black holes during inflation.

   hep-phastro-ph.COPoS(2018)·1 citation
3. 03*

   Could the 21-cm absorption be explained by the dark matter suggested by ${}^8$Be transitions?

   Lian-Bao Jia🇨🇳 · Xian-Jin Deng🇨🇳 · Chang-Fu Liu🇨🇳

   The stronger than expected 21-cm absorption was observed by EDGES recently, and another anomaly of ${}^8$Be transitions would be signatures of new interactions. These two issues may be related to each other, e.g., pseudoscalar $A$ mediated fermionic millicharged dark matter (DM), and the 21-cm absorption could be induced by photon mediated scattering between MeV millicharged DM and hydrogen. This will be explored in this paper. For fermionic millicharged DM $\bar{\chi }\chi$ with masses in a range of $2m_A<2m_{\chi }<3m_A$, the p-wave annihilation $\bar{\chi }\chi \to AA$ would be dominant during DM freeze-out. The s-wave annihilation $\bar{\chi }\chi$ $\to A,\gamma$ $\to e^{+}{e}^{-}$ is tolerant by constraints from CMB and the 21-cm absorption. The millicharged DM can evade constraints from direct detection experiments. The process of $K^{+}\to {\pi }^{+}{\pi }^0$ with the invisible decay ${\pi }^0\to \bar{\chi }\chi$ could be employed to search for the millicharged DM, and future high intensity $K^{+}$ sources, such as NA62, will do the job.

   hep-phastro-ph.COEPJC(2018)·9 citations
4. 04*

   Charmed Baryon Decay to a Strange Baryon Plus a Pion Using QCD Sum Rules

   Leonard S. Kisslinger🇺🇸 · Bijit Singha🇺🇸

   This is an extension of the prediction of strange baryon decays to the decays of charmed baryons using QCD Sum Rules. Using QCD Sum Rules we estimate the decay ${\Lambda }_c^{+}(udc)\to {\Lambda }_s^o(uds)+{\pi }^{+}$. Although some weak decays of the ${\Lambda }_c^{+}$ have been measured, since it is difficult to measure ${\Lambda }_c^{+}\to {\Lambda }_s^o+{\pi }^{+}$ our estimates should be useful for future experiments

   hep-phInt.J.Mod.Phys.A(2019)·2 citations
5. 05*

   Extended Higgs sector beyond the MSSM and the LHC

   Rui Santos🇵🇹

   One Higgs was found. Are there more? In this work we discuss simple extension of the scalar sector of the Standard Model (SM) used as benchmark models by ATLAS and CMS in the searches for new scalars at the LHC. We discuss how much the discovered 125 GeV Higgs at the LHC resembles the SM Higgs and how will our understanding of the Higgs nature improve at future electron-positron colliders. Models with extended Higgs sectors provide very interesting scenarios, from the existence of charged Higgs bosons to CP-violating scalars that can be probed by the experimental collaborations at the LHC. Comparison between the rates in the different models show that in some cases the models could be distinguished.

   hep-phPoS(2018)·0 citations
6. 06*

   Analysis of $D_s^{\ast }{D}^{\ast }{K}^{\ast }$ and $D_{s1}{D}_1{K}^{\ast }$ vertices in three-point sum rules

   M. Janbazi🇮🇷 · R. Khosravi🇮🇷 · E. Noori🇮🇷

   In this study, the coupling constant of $D_s^{\ast }{D}^{\ast }{K}^{\ast }$ and $D_{s1}{D}_1{K}^{\ast }$ vertices were determined within the three-point Quantum chromodynamics sum rules method with and without consideration of the $S{U}_f(3)$ symmetry. The coupling constants were calculated for off-shell charm and K${}^{\ast }$ cases. Considering the non-perturbative effect of the correlation function, as the most important contribution, the quark-quark, quark-gluon, and gluon-gluon condensate corrections were estimated and were compared with other predictive methods.

   hep-phAdv.High Energy Phys.(2018)·6 citations
7. 07*

   A phenomenological model of QCD monopole hadron interactions

   Aiichi Iwazaki🇯🇵

   Monopoles have recently been discussed to be a dominant component in strong coupled quark gluon plasma ( QGP ) and to play a role for chiral symmetry breaking as well as quark confinement. We analyze monopole quark interactions and show that massless quarks colliding with the monopoles inevitably change their chiralities keeping their flavors. The monopole quark interaction explicitly breaks the chiral symmetry ( SU${}_A(2)\times$U${}_A$(1) ) just like bare quark masses. It is given by $\bar{q}q{\Phi }^{†}\Phi$ with the monopole field $\Phi$. The pions are not Nambu-Goldstone bosons even in the vanishing bare quark masses. Their masses are mainly determined by the interaction because the monopole condensation generates a larger current quark mass than the bare quark masses. Based on the analysis of the monopole quark interaction, we propose a phenomenological linear sigma model coupled with the monopoles. The monopoles couple only with isoscalar scalar mesons e.g. sigma meson $\sigma$ such as $\sigma {\Phi }^{†}\Phi$ indicated by the monopole quark interaction. The coupling explicitly breaks the chiral SU(2)${}_A\times$U${}_A$(1) symmetry. Pion masses are generated by the chiral condensate, which arises only when the monopole condensate takes place. We show that one of the monopoles is a color singlet and observable. The monopole decays into hadrons ( pions, kaon, etc. ) through the coupling. Our analysis indicates that $f_0(1500)$ meson is a candidate of the observable monopole. As phenomenological effects of these monopoles, we point out that the masses of hadrons decrease in dense nuclear matters and that chiral magnetic effects disappear in strong coupled QGP.

   hep-ph0 citations
8. 08*

   Relating hadronic CP-violation to higher-twist distributions

   Chien-Yeah Seng🇨🇳

   The nucleon sigma term of the isoscalar and isovector quark chromo-magnetic dipole moments are essential inputs for the determination of the CP-odd pion-nucleon couplings induced by quark chromo-electric dipole moments. We demonstrate that the former can be mapped to the third moment of the nucleon twist-three chiral-odd distribution functions $e^q(x)$ which are in principle measurable in semi-inclusive deep inelastic scattering processes. We perform a survey on existing model calculations as well as experimental data on $e^u(x)+e^d(x)$ and derive a predicted range for the isoscalar chromo-magnetic dipole moment sigma term.

   hep-phhep-exnucl-thPRL(2019)·19 citations
9. 09*

   ${\eta }^{\prime }$ and $\eta$ mesons at high T when the U_A(1) and chiral symmetry breaking are tied

   Davor Horvatić🇭🇷 · Dalibor Kekez🇭🇷 · Dubravko Klabučar🇭🇷

   The approach to the eta'-eta complex employing chirally well-behaved quark-antiquark bound states and incorporating the non-Abelian axial anomaly of QCD through the generalization of the Witten-Veneziano relation, is extended to finite temperatures. Employing the chiral condensate has led to a sharp chiral and U_A(1) symmetry restoration, but with the condensates of quarks with realistic explicit chiral symmetry breaking, which exhibit a smooth, crossover chiral symmetry restoration in qualitative agreement with lattice QCD results, we get a crossover U_A(1) transition, with smooth and gradual melting of anomalous mass contributions. This way we obtain a substantial drop of the eta' mass around the chiral transition temperature, but no eta mass drop. This is consistent with the present empirical evidence.

   hep-phnucl-thPRD(2019)·20 citations
10. 10*

    Soft anomalous dimension matrices in heavy quark-antiquark hadroproduction in association with a gluon jet

    Ewelina Szarek🇵🇱

    We compute the soft anomalous dimension (SAD) matrices for production of massive quarks $Q$ and $\bar{Q}$ in association with a gluon jet, from massless quarks $q$ and antiquarks $\bar{q}$: $q\bar{q}\to Q\bar{Q}g$, and in the gluon scattering $gg\to Q\bar{Q}g$. To analyze the behaviour of the eigenvalues of SAD matrices we perform numerical studies of their eigensystems at two special kinematical configurations.

    hep-phActa Phys.Polon.B(2018)·3 citations
11. 11*

    What Physics Does The Charged Lepton Mass Relation Tell Us?

    Yoshio Koide🇯🇵

    The charged lepton mass relation $K\equiv (m_e+m_{\mu }+m_{\tau })/(\sqrt{m_e}$ is excellently satisfied by observed masses (pole masses). However, the formula $K=2/3$ should be never satisfied with the observed charged lepton masses. We will review a mechanism by proposed by Sumino and recent related topics.

    hep-ph3 citations
12. 12*

    Accurate predictions for top-quark pair production at the LHC

    Silvia Ferrario Ravasio🇮🇹

    The top quark is the heaviest elementary particle in the Standard Model (SM). For this reason, a precise determination of its mass $m_t$ is part of the LHC physics program. The most accurate determinations of $m_t$ rely on the kinematic reconstruction of the top decay products and on the use of Monte Carlo event generators. In these proceedings I discuss the impact of different theoretical descriptions for the process of top pair production at the LHC on the extraction of $m_t$.

    hep-phhep-exNuovo Cim.C(2019)·0 citations
13. 13*

    Probing and Distinguishing Representations at the LHC

    Antonio Costantini🇮🇹

    The discovery made at the Large Hadron Collider (LHC) has revealed that the spontaneous symmetry breaking mechanism is realised in a gauge theory such as the Standard Model (SM) by at least one Higgs doublet. However, the possible existence of other scalar bosons cannot be excluded. We analyze signatures extensions of the SM, characterized by an extra representations of scalars, in view of the recent and previous Higgs data. We show that such representations can be probed and distinguished, mostly with multileptonic final states, with a relatively low luminosity at the LHC.

    hep-phPoS(2018)·0 citations
14. 14*

    Inclusive ${\chi }_{cJ}$ production in ${\rm Y}$ decay at $\mathcal{O}({\alpha }_s^5)$ in NRQCD factorization

    Zhi-Guo He🇩🇪 · Bernd A. Kniehl🇩🇪 · Xiang-Peng Wang🇩🇪

    Inclusive ${\chi }_{cJ}$ $(J=0,1,2)$ production from ${\rm Y}(1S)$ decay is studied within the framework of nonrelativistic QCD (NRQCD) factorization at leading order in $v_Q^2$, which includes the contributions of $b\bar{b}({}^3{S}_1^{[1]})\to c\bar{c}{(}^3{P}_J^{[1]})+X$ and $b\bar{b}({}^3{S}_1^{[1]})\to c\bar{c}{(}^3{S}_1^{[8]})+X$. For both channels, the short-distance coefficients are calculated through $\mathcal{O}({\alpha }_s^5)$, which is next-to-leading order for the second one. By fitting to the measured ${\rm Y}(1S)$ branching fractions to ${\chi }_{c1}$ and ${\chi }_{c2}$, we obtain the color-octet long-distance matrix element (LDME) $⟨{\mathcal{O}}^{{\chi }_{c0}}({}^3{S}_1^{[8]})⟩=(4.04\pm 0.47_{-0.34}^{+0.67})\times 10^{-3}$ GeV${}^3$, where the first error is experimental and the second one due to the renormalization scale dependence, if we use as input $⟨{\mathcal{O}}^{{\chi }_{c0}}({}^3{P}_0^{[1]})⟩=0.107$ GeV${}^5$ as obtained via potential-model analysis. Previous LDME sets, extracted from data of prompt ${\chi }_{cJ}$ hadroproduction, yield theoretical predictions that systematically undershoot or mildly overshoot the experimental values of $\mathcal{B}({\rm Y}\to {\chi }_{cJ}+X)$.

    hep-phPRD(2018)·1 citation
15. 15*

    Rare Leptonic B decays

    Gilberto Tetlalmatzi-Xolocotzi🇳🇱

    The transitions $B_{s,d}\to {\ell }^{+}{\ell }^{-}$ (for $\ell =e,\mu ,\tau$), although extremely suppressed within the SM, are exceptionally clean channels particularly sensitive to New Physics contributions. So far only the branching ratio for the process $B_s\to {\mu }^{+}{\mu }^{-}$ has been measured experimentally and, although the results are in agreement with the SM prediction, there is still room for NP effects. Here we provide an overview of the theoretical status of rare decays. We present strategies that can allow us to discriminate between different NP scenarios. Finally, we include a discussion of the effects of nontrivial new CP violating phases on the observables associated with $B_s\to {\mu }^{+}{\mu }^{-}$.

    hep-phPoS(2018)·1 citation
16. 16*

    Charged lepton flavor violation and electric dipole moments in the inert Zee model

    Alexandra Gaviria🇨🇴 · Robinson Longas🇨🇴 · Óscar Zapata🇨🇴

    The inert Zee model is an extension of the Zee model for neutrino masses to allow for a solution to the dark matter problem that involves two vector-like fields, a doublet and a singlet of $SU(2{)}_L$, and two scalars, also a doublet and a singlet of $SU(2{)}_L$, all of them being odd under an exact $Z_2$ symmetry. The introduction of the $Z_2$ guarantees one-loop neutrino masses, forbids tree-level Higgs-mediated flavor changing neutral currents and ensures the stability of the dark matter candidate. Due to the natural breaking of lepton numbers in the inert Zee model and encouraged by the ambitious experimental program designed to look for charged lepton flavor violation signals and the electron electric dipole moment, we study the phenomenology of the processes leading to these kind of signals, and establish which are the most promising experimental perspectives on that matter.

    hep-phJHEP(2018)·8 citations
17. 17*

    Constraints on MeV dark matter using neutrino detectors and their implication for the 21-cm results

    Niki Klop🇳🇱 · Shin'ichiro Ando🇳🇱

    The recent results of the EDGES collaboration indicate that during the era of reionization, the primordial gas was much colder than expected. The cooling of the gas could be explained by interactions between dark matter (DM) and particles in the primordial gas. Constraints from cosmology and particle experiments indicate that this DM should be light ($\sim$10-80 MeV), carry a small charge ($ϵ\sim 10^{-6}$-$10^{-4}$), and only make up a small fraction of the total amount of DM. Several constraints on the DM parameter space have already been made. We explore the yet unconstrained region in the case that the milli-charged DM makes up for $\sim$2\% of the total dark matter, through the scenario in which this DM annihilates only into mu and tau neutrinos. We set upper limits on the annihilation cross section using the Super-Kamiokande data, and predict the limits that could be obtained through Hyper-Kamiokande, JUNO and DUNE. We find that data from Super-Kamiokande is not yet able to constrain this model, but future experiments might be. We furthermore explore DM annihilation into solely neutrinos in general, giving an update of the current limits, and predict the limits that could be placed with future experiments.

    hep-phastro-ph.COhep-exPRD(2018)·28 citations
18. 18*

    Inter-node superconductivity in strained Weyl semimetals

    P. O. Sukhachov🇨🇦 · E. V. Gorbar🇺🇦 · I. A. Shovkovy🇺🇸 · V. A. Miransky🇨🇦

    The effects of a strain-induced pseudomagnetic field on inter-node spin-triplet superconducting states in Weyl semimetals are studied by using the quasiclassical Eilenberger formalism. It is found that the Cooper pairing with spins parallel to the pseudomagnetic field has the lowest energy among the spin-triplet states and its gap does not depend on the strength of the field. In such a state, both electric and chiral superconducting currents are absent. This is in contrast to the superconducting states with the spins of Cooper pairs normal to the field, which support a nonzero chiral current and are inhibited by the strain-induced pseudomagnetic field. The corresponding critical value of the field, which separates the normal and superconducting phases, is estimated.

    ↳ cond-mat.supr-concond-mat.str-elhep-phJ.Phys.Condens.Matter(2018)·8 citations
19. 19*

    Large $N_c$ Thermodynamics with Dynamical Fermions

    Thomas DeGrand🇺🇸 · Daniel C. Hackett🇺🇸 · Ethan T. Neil🇺🇸

    We present a progress report on our investigation of the thermodynamics of QCD with $N_f=2$ flavors of dynamical Wilson fermions in the limit of a large number of colors $N_c$. To date, studies of the thermodynamics of QCD at large $N_c$ have been limited to the quenched approximation, i.e., to the behavior of pure $\mathrm{SU}(N_c)$ gauge theory at large $N_c$. This is the first study of thermodynamics at large $N_c$ using dynamical fermions, and thus the first study able to test whether the quenched approximation is a valid way to investigate large $N_c$ thermodynamics. After reviewing 't Hooft's large $N_c$ limit, we discuss the automation we use to make this study feasible, and finally compare our preliminary physics results for $\mathrm{SU}(3-5)$ with large $N_c$ expectations.

    ↳ hep-lathep-phPoS(2018)·4 citations
20. 20*

    Gravi-Weak Unification and the Black-Hole-Hedgehog's Solution with Magnetic Field Contribution

    B.G. Sidharth🇮🇳 · C.R. Das🇷🇺 · L.V. Laperashvili🇷🇺 · H.B. Nielsen🇩🇰

    In the present paper, we investigated the gravitational black-hole-hedgehog's solution with magnetic field contribution in the framework of the f(R)--gravity described by the Gravi-Weak unification model. Assuming the Multiple Point Principle (MPP), we considered the existence of the two degenerate vacua of the Universe: the first Electroweak (EW) vacuum with $v_1\approx 246$ GeV ("true vacuum"), and the second Planck scale ("false vacuum") with $v_2\sim 10^{18}$ GeV. In these vacua, we investigated different topological defects. The main aim of this paper is an investigation of the black-hole-hedgehog configurations as defects of the "false vacuum". We have obtained the solution which corresponds to a global monopole, that has been "swallowed" by the black-hole with core mass $M_{BH}\approx 3.65\times 10^{18}\mathrm{GeV}$ and radius $\delta \approx 6\cdot 10^{-21}{\mathrm{GeV}}^{-1}.$ We investigated the metric in the vicinity of the black-hole-hedgehog and estimated its horizon radius: $r_h\approx 1.14\delta$. We have considered the phase transition from the "false vacuum" to the "true vacuum" and confirmed the stability of the EW--vacuum.

    ↳ gr-qchep-phhep-thInt.J.Mod.Phys.A(2018)·5 citations
21. 21*

    Search for muoproduction of the X(3872) at COMPASS

    Alexey Guskov (for the COMPASS collaboration)🇷🇺

    Exotic charmonium-like states have been observed by various experiments over the last 15 years, but their nature is still under discussion. Photo-(muo)production is a new promising instrument to study them. COMPASS, a fixed target experiment at CERN, analyzed the full set of the data collected with a muon beam between 2002 and 2011, covering the range from 7 GeV to 19 GeV in the centre-of-mass energy of the virtual photon-nucleon system. A signal in the mass spectrum of $J/\psi {\pi }^{+}{\pi }^{-}$ with the statistical significance of 4.1 $\sigma$ was observed in the reaction ${\mu }^{+}N\to {\mu }^{+}(J/\psi {\pi }^{+}{\pi }^{-}){\pi }^{\pm }{N}^{\prime }$. Its mass and width are consistent with those of the $X(3872)$. The shape of the ${\pi }^{+}{\pi }^{-}$ mass distribution from the observed decay into $J/\psi {\pi }^{+}{\pi }^{-}$ is different from previous observations for $X(3872)$. The observed signal may be interpreted as possible evidence of a new charmonium state $\tilde{X}(3872)$. It could be associated with a neutral partner of $X(3872)$ with $C=-1$ predicted by a tetraquark model.

    ↳ hep-exhep-phJ.Phys.Conf.Ser.(2019)·1 citation
22. 22*

    Meson correlation functions at high temperature QCD: $SU(2{)}_{CS}$ symmetry vs. free quarks

    C. Rohrhofer🇦🇹 · Y. Aoki🇯🇵 · G. Cossu🇬🇧 · L. Ya. Glozman🇦🇹 · S. Hashimoto🇯🇵 · S. Prelovsek🇸🇮

    We report on the progress of understanding spatial correlation functions in high temperature QCD. We study isovector meson operators in $N_f=2$ QCD using domain-wall fermions on lattices of $N_s=32$ and different quark masses. It has previously been found that at $\sim 2T_c$ these observables are not only chirally symmetric but in addition approximately $SU(2{)}_{CS}$ and $SU(4)$ symmetric. In this study we increase the temperature up to $5T_c$ and can identify convergence towards an asymptotically free scenario at very high temperatures.

    ↳ hep-lathep-phhep-thnucl-thPoS(2018)·5 citations
23. 23*

    Neutron-antineutron oscillations from lattice QCD

    Enrico Rinaldi🇺🇸 · Sergey Syritsyn🇺🇸 · Michael L. Wagman🇺🇸 · Michael I. Buchoff🇺🇸 · Chris Schroeder🇺🇸 · Joseph Wasem🇺🇸

    Fundamental symmetry tests of baryon number violation in low-energy experiments can probe beyond the Standard Model (BSM) explanations of the matter-antimatter asymmetry of the universe. Neutron-antineutron oscillations are predicted to be a signature of many baryogenesis mechanisms involving low-scale baryon number violation. This work presents first-principles calculations of neutron-antineutron matrix elements needed to accurately connect measurements of the neutron-antineutron oscillation rate to constraints on $|\Delta B|=2$ baryon number violation in BSM theories. Several important systematic uncertainties are controlled by using a state-of-the-art lattice gauge field ensemble with physical quark masses and approximate chiral symmetry, performing nonperturbative renormalization with perturbative matching to the $\overline{\text{MS}}$ scheme, and studying excited state effects in two-state fits. Phenomenological implications are highlighted by comparing expected bounds from proposed neutron-antineutron oscillation experiments to predictions of a specific model of post-sphaleron baryogenesis. Quantum chromodynamics is found to predict at least an order of magnitude more events in neutron-antineutron oscillation experiments than previous estimates based on the "MIT bag model" for fixed BSM parameters. Lattice artifacts and other systematic uncertainties that are not controlled in this pioneering calculation are not expected to significantly change this conclusion.

    ↳ hep-lathep-phnucl-thPRL(2019)·45 citations
24. 24*

    The system of partial differential equations for the $C_{{}_0}$ function

    Tai-Fu Feng🇨🇳 · Chao-Hsi Chang🇨🇳 · Jian-Bin Chen🇨🇳 · Hai-Bin Zhang🇨🇳

    We present an approach to analyze the scalar integrals of any Feynman diagrams in detail here. This method not only completely recovers some well-known results in the literature, but also produces some brand new results on the $C_{{}_0}$ function. The approach can be employed to evaluate the coefficient of arbitrary power of $\epsilon$ in the expansion of a scalar integral, where $D=4-2\epsilon$ denotes the time-space dimension.

    ↳ hep-thhep-phNPB(2019)·15 citations
25. 25*

    Complete experiments in pseudoscalar meson photoproduction revisited

    K. Nakayama🇺🇸

    By exploiting the underlying symmetries of the relative phases of the pseudoscalar meson photoproduction amplitude, we determine all the possible sets of four double-spin observables that resolve the phase ambiguity of the amplitude in transversity basis up to an overall phase. The present results corroborate the original findings by Chiang and Tabakin [Phys. Rev. C 55, 2054 (1997)]. However, it is found that the completeness condition of four double-spin observables to resolve the phase ambiguity holds only when the relative phases do not meet the condition of equal magnitudes. In situations where this condition occurs, it is shown that one needs extra chosen observables, resulting in the minimum number of observables required to resolve the phase ambiguity to reach up to eight, depending on the particular set of four double-spin observables considered. Furthermore, a way of gauging when the condition of equal magnitudes occurs is provided.

    ↳ nucl-thhep-phPRC(2019)·12 citations
26. 26*

    Do We Live in the Swampland?

    Hitoshi Murayama🇺🇸 · Masahito Yamazaki🇯🇵 · Tsutomu T. Yanagida🇯🇵

    A low-energy effective theory is said to be in the swampland if it does not have any consistent UV completion inside a theory of quantum gravity. The natural question is if the standard model of particle physics, possibly with some minimal extensions, are in the swampland or not. We discuss this question in view of the recent swampland conjectures. We prove a no-go theorem concerning the modification of the Higgs sector. Moreover, we find that QCD axion is incompatible with the recent swampland conjectures, unless some sophisticated possibilities are considered. We discuss the implications of this result for spontaneous breaking of CP symmetry. We comment on dynamical supersymmetry breaking as well as the issue of multi-valuedness of the potential.

    ↳ hep-thhep-phJHEP(2018)·132 citations
27. 27*

    Effect of Confinement of Gluons and One Pion Exchange in Nucleon-Nucleon Interaction

    V K Nilakanthan🇮🇳 · V C Shastry🇮🇳 · S Raghavendra🇮🇳 · K B Vijaya Kumar🇮🇳

    The Nucleon-Nucleon interaction in the singlet (${}^1{S}_0$) and triplet (${}^3{S}_1$) channels have been studied in the framework of Relativistic Harmonic Model using the Resonating Group Method in Born-Oppenheimer approximation. The full Hamiltonian consists of the kinetic energy, two body confinement potential, confined one gluon exchange potential and one pion exchange potential. Contribution of Confined One Gluon Exchange Potential and One Pion Exchange Potential to the adiabatic nucleon-nucleon interaction potential is discussed.

    ↳ nucl-thhep-phEur.Phys.J.Plus(2019)·3 citations
28. 28*

    Effective Field Theory in The Study of Long Range Nuclear Parity Violation on Lattice

    Feng-Kun Guo🇨🇳 · Chien-Yeah Seng🇨🇳

    A non-zero signal $A_{\gamma }^{\mathrm{np}}=(-3.0\pm 1.4\pm 0.2)\times 10^{-8}$ of the gamma-ray asymmetry in the neutron-proton capture was recently reported by the NPDGamma Collaboration which provides the first determination of the $\Delta I=1$ parity-odd pion-nucleon coupling constant $h_{\pi }^1=(2.6\pm 1.2\pm 0.2)\times 10^{-7}$. The ability to reproduce this value from first principles serves as a direct test of our current understanding of the interplay between the strong and weak interaction at low energy. To motivate new lattice studies of $h_{\pi }^1$, we review the current status of the theoretical understanding of this coupling, which includes our recent work that relates it to a nucleon mass-splitting by a soft-pion theorem. We further investigate the possibility of calculating the mass-splitting on the lattice by providing effective field theory parameterizations of all the involved quark contraction diagrams. We show that the lattice calculations of the easier connected diagrams will provide information of the chiral logarithms in the much harder quark loop diagrams and thus help in the chiral extrapolation of the latter.

    ↳ nucl-thhep-lathep-phnucl-exEPJC(2019)·12 citations
29. 29*

    Isolating dynamical net-charge fluctuations

    Rudolph Rogly🇫🇷 · Giuliano Giacalone🇫🇷 · Jean-Yves Ollitrault🇫🇷

    We modify the usual definitions of cumulants of net-charge fluctuations in a way that isolates dynamical fluctuations. The new observables, which we call dynamical cumulants, are robust with respect to trivial correlations induced by volume fluctuations and global charge conservation. We illustrate the potential of dynamical cumulants by carrying out Monte Carlo simulations where all correlations are trivial. The results of our simulations agree well with Relativistic Heavy Ion Collider (RHIC) data, and are used to illustrate that dynamical cumulants consistently isolate dynamical fluctuations.

    ↳ nucl-thhep-phnucl-exPRC(2019)·9 citations
30. 30*

    Conductivities of magnetic quark-gluon plasma at strong coupling

    Wei Li🇨🇳 · Shu Lin🇨🇳 · Jiajie Mei🇨🇳

    In the presence of a strong magnetic field, the quark gluon plasma is magnetized, leading to anisotropic transport coefficients. In this work, we focus on the effect of magnetization on electric conductivity, ignoring the possible contribution from the axial anomaly. We generalize longitudinal and transverse conductivities to finite frequencies. For transverse conductivity, a separation of contribution from fluid velocity is needed. We study the dependence of the conductivities on the magnetic field and frequency using a holographic magnetic brane model. The longitudinal conductivity scales roughly linearly in the magnetic field, while the transverse conductivity is rather insensitive to the magnetic field. Furthermore, we find the conductivities can be significantly enhanced at large frequency. This can possibly extend the lifetime of the magnetic field, which is a key component of the chiral magnetic effect.

    ↳ hep-thhep-phnucl-thPRD(2018)·30 citations
31. 31*

    Collisions of cosmic strings with chiral currents

    I. Yu. Rybak🇵🇹 · A. Avgoustidis🇬🇧 · C. J. A. P. Martins🇵🇹

    We present an analytic study of cosmic superconducting chiral string collisions in Minkowski space, applying the kinematic constraints that arise from the relevant generalization of the Nambu-Goto action. In particular, we revisit the solution for chiral superconducting cosmic strings and demonstrate that Y junction production for such strings is possible. We consider the collision of chiral current-carrying straight strings and obtain the region in angle-velocity space that allows the production of string junctions. This study contributes to the understanding of the complex evolution of chiral superconducting string networks.

    ↳ astro-ph.COgr-qchep-phhep-thPRD(2018)·6 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.