Wed·Nov 23, 2016Wednesday·November 23, 2016

1. 01*

   Kinetically Modified Non-Minimal Inflation With Exponential Frame Function

   C. Pallis🇨🇾

   We consider Supersymmetric (SUSY) and non-SUSY models of chaotic inflation based on the phi^n potential with n=2 or 4. We show that the coexistence of an exponential nonminimal coupling to gravity, fR=Exp(cR phi^p), with a kinetic mixing of the form fK=cK fR^m can accommodate inflationary observables favored by the Planck and Bicep2/Keck Array results for p=1 and 2, 1<=m<=15 and 2.6x10^(-3)<=rRK=cR/cK^(p/2)<=1, where the upper limit is not imposed for p=1. Inflation is of hilltop type and it can be attained for subplanckian inflaton values with the corresponding effective theories retaining the perturbative unitarity up to the Planck scale. The supergravity embedding of these models is achieved employing two chiral gauge singlet supefields, a monomial superpotential and several (semi)logarithmic or semipolynomial Kaehler potentials.

   hep-phastro-ph.COhep-thEPJC(2017)·2 citations
2. 02*

   Perspectives for Detecting Lepton Flavour Violation in Left-Right Symmetric Models

   Cesar Bonilla🇪🇸 · Manuel E. Krauss🇩🇪 · Toby Opferkuch🇩🇪 · Werner Porod🇩🇪

   We investigate lepton flavour violation in a class of minimal left-right symmetric models where the left-right symmetry is broken by triplet scalars. In this context we present a method to consistently calculate the triplet-Yukawa couplings which takes into account the experimental data while simultaneously respecting the underlying symmetries. Analysing various scenarios, we then calculate the full set of tree-level and one-loop contributions to all radiative and three-body flavour-violating fully leptonic decays as well as $\mu -e$ conversion in nuclei. Our method illustrates how these processes depend on the underlying parameters of the theory. To that end we observe that, for many choices of the model parameters, there is a strong complementarity between the different observables. For instance, in a large part of the parameter space, lepton flavour violating $\tau$-decays have a large enough branching ratio to be measured in upcoming experiments. Our results further show that experiments coming online in the immediate future, like Mu3e and BELLE II, or longer-term, such as PRISM/PRIME, will probe significant portions of the currently allowed parameter space.

   hep-phJHEP(2017)·27 citations
3. 03*

   Neutral Weak Form Factors of Proton and Neutron

   Raza Sabbir Sufian🇺🇸

   We determine the nucleon neutral weak electromagnetic form factors $G_{E,M}^{Z,p(n)}$ by combining results from light-front holographic QCD and lattice QCD calculations. We deduce nucleon electromagnetic form factors from light-front holographic QCD which provides a good parametrization of the experimental data of the nucleon electromagnetic form factors in the entire momentum transfer range and isolate the strange quark electromagnetic form factors $G_{E,M}^s$ using lattice QCD. From these calculations, we obtain precise estimates of the neutral weak form factors in the momentum transfer range of $0{\text{GeV}}^2\le Q^2\le 0.5{\text{GeV}}^2$. From the lattice QCD calculation, we present $Q^2$-dependence of the strange quark form factors. We also deduce the neutral weak Dirac and Pauli form factors $F_{1,2}^{Z,p(n)}$ of the proton and the neutron.

   hep-phhep-latnucl-thPRD(2017)·10 citations
4. 04*

   Standard model flavor from an $SU(2)$ symmetry

   Jeffrey M. Berryman🇺🇸 · Daniel Hernández🇺🇸

   We propose that the flavor structure of the standard model is based on a horizontal $SU(2)$ symmetry. It generically predicts (i) a parametrically small mass for the lightest charged fermions, (ii) small mixings in the quark sector, and (iii) suppression of flavor-changing neutral currents. Supplemented with the assumption of a strong hierarchy between the second- and third- generation masses, it also predicts (iv) a large $CP$-violating phase in the quark sector. Only Majorana neutrinos allow for large mixings in the lepton sector. In this case, this framework further predicts (v) near-maximal ${\theta }_{23}^l$, (vi) a normal hierarchy of neutrino masses, and (vii) large $CP$ violation in the lepton sector.

   hep-phPRD(2017)·8 citations
5. 05*

   $\bar{D}{\Sigma }_c^{\ast }$ and ${\bar{D}}^{\ast }{\Sigma }_c$ interactions and LHCb pentaquarks

   Jun He🇨🇳

   Recently, LHCb collaboration reported the observation of two hidden-charmed resonances $P_c(4380)$ and $P_c(4450)$ consistent with hidden-charmed pentaquarks. We perform a dynamical investigation about the $\bar{D}{\Sigma }_c^{\ast }(2520)$ and ${\bar{D}}^{\ast }{\Sigma }_c(2455)$ interactions which are described by the meson exchanges in a quasipotential Bethe-Salpeter equation approach. Two poles around $4450$ and $4390$ MeV are produced from the ${\bar{D}}^{\ast }{\Sigma }_c(2455)$ interaction with spin parities $3/2^{-}$ and $5/2^{+}$, respectively. The peak for $5/2^{+}$ state has a comparable hight as that of $3/2^{-}$ state in the $J/\psi p$ invariant mass spectrum. Another bound state with spin-parity $J^P=3/2^{-}$ is produced from the $\bar{D}{\Sigma }_c^{\ast }(2520)$ interaction. Such results suggest that the narrower LHCb pentaquark $P_c(4450)$ can be well interpreted as a $5/2^{+}$ ${\bar{D}}^{\ast }{\Sigma }_c(2455)$ molecular state while the $P_c(4380)$ is a $3/2^{-}$ ${\bar{D}}^{\ast }{\Sigma }_c(2455)$ molecular state mixed with other secondary origins.

   hep-phJPS Conf.Proc.(2017)·1 citation
6. 06*

   Weak Quasielastic Production of Hyperons

   M. Sajjad Athar🇮🇳 · F. Akbar🇮🇳 · M. Rafi Alam🇮🇳 · S. Chauhan🇮🇳 · S. K. Singh🇮🇳

   We present the results for antineutrino induced quasielastic hyperon production from nucleon and nuclear targets \cite{Alam:2014bya,Singh:2006xp}. The inputs are the nucleon-hyperon(N--Y) transition form factors determined from the analysis of neutrino-nucleon scattering and semileptonic decays of neutron and hyperons using SU(3) symmetry. The calculations for the nuclear targets are done in local density approximation. The nuclear medium effects(NME) like Fermi motion, Pauli blocking and final state interaction(FSI) effects due to hyperon-nucleon scattering have been taken into account. The hyperons giving rise to pions through weak decays also contribute to the weak pion production in addition to the $\Delta$ excitation mechanism which dominates in the energy region of $<$ 0.7 GeV. We also present the results of longitudinal and perpendicular components of polarization of final hyperon \cite{Akbar:2016awk}. These measurements in the future accelerator experiments with antineutrinos may give some information on axial vector and pseudoscalar form factors in the strangeness sector.

   hep-ph0 citations
7. 07*

   Supersymmetric Meson-Baryon Properties of QCD from Light-Front Holography and Superconformal Algebra

   Stanley J. Brodsky🇺🇸

   A remarkable feature of QCD is that the mass scale which controls color confinement and hadron mass scales does not appear explicitly in the QCD Lagrangian. However, de Alfaro, Fubini, and Furlan have shown that a mass scale can appear in the equations of motion without affecting the conformal invariance of the action if one adds a term to the Hamiltonian proportional to the dilatation operator or the special conformal operator. Applying the same procedure to the light-front Hamiltonian leads to a unique confinement potential ${\kappa }^4{\zeta }^2$ for mesons, where $\zeta$ is the LF radial variable conjugate to the invariant mass. The same result, including spin terms, is obtained using light-front holography, the duality between the front form and AdS${}_5,$ if one modifies the action by the dilaton $e^{{\kappa }^2{z}^2}$ in the fifth dimension $z$. Generalizing this procedure using superconformal algebra, leads to a unified Regge spectroscopy of meson, baryon, and tetraquarks, including remarkable supersymmetric relations between the masses of mesons and baryons of the same parity. One also predicts observables such as hadron structure functions, transverse momentum distributions, and the distribution amplitudes defined from the hadronic light-front wavefunctions. The mass scale underlying confinement and hadron masses can be connected to the mass parameter in the QCD running coupling by matching the nonperturbative dynamics to the perturbative QCD regime. The result is an effective coupling defined at all momenta and the determination of a momentum scale which sets the interface between perturbative and nonperturbative hadron dynamics. I also discuss evidence that the antishadowing of nuclear structure functions is non-universal, and why shadowing and antishadowing phenomena may be incompatible with sum rules for nuclear parton distribution functions.

   hep-phFew Body Syst.(2017)·5 citations
8. 08*

   $K\to \pi {\ell }^{+}{\ell }^{-}$: Status and update

   Jorge Portoles (IFIC, Valencia)🇪🇸

   $K\to \pi {\ell }^{+}{\ell }^{-}$ decays, $\ell =e,\mu$, will be one of the goals of future kaon facilities, like NA62 (CERN) and K${}^0$TO (J-PARC). We review briefly the theoretical status of those processes.

   hep-phhep-exJ.Phys.Conf.Ser.(2017)·1 citation
9. 09*

   Effect of medium recoil and $p_T$ broadening on single inclusive jet suppression in high-energy heavy-ion collisions

   Xin-Nian Wang🇨🇳 · Shu-Yi Wei🇨🇳 · Han-Zhong Zhang🇨🇳

   Jet energy loss and single inclusive jet suppression in high-energy heavy-ion collisions are studied within a pQCD parton model that includes both elastic and radiative interactions between jet shower and medium partons as they propagate through the quark-gluon plasma. The collisional energy loss of jets with a given cone-size is found to be relatively small comparing with the radiative energy loss. However the effect of transverse momentum broadening due to elastic scattering is significant in the calculation of radiative energy loss within the higher-twist formalism. The nuclear modification factors for single inclusive jets with different cone-sizes are calculated and compared to experimental data as measured by ALICE and ATLAS experiments in Pb+Pb collisions at $\sqrt{s_{\mathrm{NN}}}=2.76$ TeV. Results on jet suppression in Pb+Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV are also presented.

   hep-phnucl-thPRC(2017)·23 citations
10. 10*

    A practical guide to event generation for prompt photon production

    Frank Siegert🇩🇪

    The production of prompt photons is one of the most relevant scattering processes studied at hadron-hadron colliders in recent years. This article will give an overview of the different approaches used to simulate prompt photon production in the Sherpa event generator framework. Special emphasis is placed on a complete simulation of this process including fragmentation configurations. As a novel application a merged simulation of $\gamma \gamma$ and $\gamma \gamma +$jet production at NLO accuracy is presented and compared to measurements from the ATLAS experiment.

    hep-phJ.Phys.G(2017)·94 citations
11. 11*

    Backward charmonium production in $\pi N$ collisions

    B. Pire🇫🇷 · K. Semenov-Tian-Shansky🇷🇺 · L. Szymanowski🇵🇱

    The QCD collinear factorization framework allows to describe exclusive backward production of a $J/\psi$ meson in pion-nucleon collisions in terms of pion-to-nucleon transition distribution amplitudes. We calculate the scattering amplitude at the leading order in the strong coupling constant and estimate the cross section of this reaction in the backward kinematical region for a medium energy pion beam available at the J-Parc experimental facility.

    hep-phhep-exnucl-exnucl-thPRD(2017)·13 citations
12. 12*

    The Generalized Scheme-Independent Crewther Relation in QCD

    Jian-Ming Shen🇨🇳 · Xing-Gang Wu🇨🇳 · Yang Ma🇺🇸 · Stanley J. Brodsky🇺🇸

    The Principle of Maximal Conformality (PMC) provides a systematic way to set the renormalization scales order-by-order for any perturbative QCD process. The resulting predictions are independent of the choice of renormalization scheme, a requirement of renormalization group invariance. The Crewther relation, which was originally derived for conformal theory, provides a remarkable connection between two observables when the $\beta$ function vanishes. The "Generalized Crewther Relation" relates these two observables for physical QCD with nonzero $\beta$ function; specifically, it connects the non-singlet Adler function ($D^{\mathrm{ns}}$) to the Bjorken sum rule coefficient for polarized deep-inelastic electron scattering ($C_{\mathrm{Bjp}}$) at leading twist. A scheme-dependent ${\Delta }_{\mathrm{CSB}}$-term appears in the analysis in order to compensate for the conformal symmetry breaking (CSB) terms from perturbative QCD. In conventional analyses, this normally leads to unphysical dependence in both the choice of the renormalization scheme and the choice of the initial scale at any finite order. However, by applying PMC scale-setting, we can fix the scales of the QCD coupling unambiguously at every order of pQCD. ...... Thus one obtains a new generalized Crewther relation for QCD which connects two effective charges, ${\hat{\alpha }}_d(Q)={\sum }_{i\ge 1}{\hat{\alpha }}_{g_1}^i(Q_i)$, at their respective physical scales. This identity is independent of the choice of the renormalization scheme at any finite order, and the dependence on the choice of the initial scale is negligible. Similar scale-fixed commensurate scale relations also connect other physical observables at their physical momentum scales, thus providing convention-independent, fundamental precision tests of QCD.

    hep-phPLB(2017)·21 citations
13. 13*

    Asymptotic freedom in the Hamiltonian approach to binding of color

    María Gómez-Rocha🇮🇹

    We derive asymptotic freedom and the $SU(3)$ Yang-Mills $\beta$-function using the renormalization group procedure for effective particles. In this procedure, the concept of effective particles of size $s$ is introduced. Effective particles in the Fock space build eigenstates of the effective Hamiltonian $H_s$, which is a matrix written in a basis that depend on the scale (or size) parameter $s$. The effective Hamiltonians $H_s$ and the (regularized) canonical Hamiltonian $H_0$ are related by a similarity transformation. We calculate the effective Hamiltonian by solving its renormalization-group equation perturbatively up to third order and calculate the running coupling from the three-gluon-vertex function in the effective Hamiltonian operator.

    hep-phEPJ Web Conf.(2017)·0 citations
14. 14*

    Electromagnetic proton form factors in dual large-$N_c$ QCD: an update

    B. Bisschoff🇿🇦 · C. A. Dominguez🇿🇦 · L. A. Hernandez🇿🇦

    An updated determination is presented of the electric and magnetic form factors of the proton, in the framework of a dual-model realization of QCD in the limit of an infinite number of colors. Very good agreement with data is obtained in the space-like region up to $q^2\simeq -30{GeV}^2$. In particular, the ratio ${\mu }_P{G}_E(q^2)/G_M(q^2)$ is predicted in very good agreement with recoil polarization measurements from Jefferson Lab, up to $q^2\simeq -8.5{GeV}^2$. \end{abstract}

    hep-phMod.Phys.Lett.A(2017)·1 citation
15. 15*

    Loop corrections to pion and kaon neutrinoproduction

    Marat Siddikov🇨🇱 · Ivan Schmidt🇨🇱

    In this paper we study the next-to-leading order corrections to deeply virtual pion and kaon production in neutrino experiments. We estimate these corrections in the kinematics of the Minerva experiment at FERMILAB, and find that they are sizable and increase the leading order cross-section by up to a factor of two. We provide a code, which can be used for the evaluation of the cross-sections, taking into account these corrections and employing various GPD models.

    hep-phhep-exPRD(2017)·9 citations
16. 16*

    From asymptotic freedom toward heavy quarkonia within the renormalization group procedure for effective particles

    María Gómez-Rocha🇮🇹

    The renormalization group procedure for effective particles (RGPEP), developed as a nonperturbative tool for constructing bound states in quantum field theories, is applied to QCD. The approach stems from the similarity renormalization group and introduces the concept of effective particles. It has been shown that the RGPEP passes the test of exhibiting asymptotic freedom. We present the running of the Hamiltonian coupling with the renormalization-group scale and summarize the basic elements needed in the formulation of the bound-state problem.

    hep-phFew Body Syst.(2017)·4 citations
17. 17*

    Theta angle in holographic QCD

    Matti Jarvinen🇫🇷

    V-QCD is a class of effective holographic models for QCD which fully includes the backreaction of quarks to gluon dynamics. The physics of the theta-angle and the axial anomaly can be consistently included in these models. We analyze their phase diagrams over ranges of values of the quark mass, N_f/N_c, and theta, computing observables such as the topological susceptibility and the meson masses. At small quark mass, where effective chiral Lagrangians are reliable, they agree with the predictions of V-QCD.

    hep-phhep-thEPJ Web Conf.(2017)·0 citations
18. 18*

    Semileptonic ${\Lambda }_b\to {\bar{\nu }}_{l}l{\Lambda }_c(2595)$ and ${\Lambda }_b\to {\bar{\nu }}_{l}l{\Lambda }_c(2625)$ decays in the molecular picture of ${\Lambda }_c(2595)$ and ${\Lambda }_c(2625)$

    Wei-Hong Liang🇨🇳 · Eulogio Oset🇪🇸 · Zhu-Sheng Xie🇨🇳

    We evaluate the partial decay widths for the semileptonic ${\Lambda }_b\to {\bar{\nu }}_{l}l{\Lambda }_c(2595)$ and ${\Lambda }_b\to {\bar{\nu }}_{l}l{\Lambda }_c(2625)$ decays from the perspective that these two ${\Lambda }_c^{\ast }$ resonances are dynamically generated from the $DN$ and $D^{\ast }N$ interaction with coupled channels. We find that the ratio of the rates obtained for these two reactions is compatible with present experimental data and is very sensitive to the $D^{\ast }N$ coupling, which becomes essential to obtain agreement with experiment. Together with the results obtained for the ${\Lambda }_b\to {\pi }^{-}{\Lambda }_c^{\ast }$ reactions, it gives strong support to the molecular picture of the two ${\Lambda }_c^{\ast }$ resonances and the important role of the $D^{\ast }N$ component neglected in prior studies of the ${\Lambda }_c(2595)$ from the molecular perspective.

    hep-phPRD(2017)·15 citations
19. 19*

    Computation of NLO Processes Involving Heavy Quarks Using Loop-Tree Duality

    Felix Driencourt-Mangin🇪🇸

    We present a new method to compute higher-order corrections to physical cross-sections, at Next-to-Leading Order and beyond. This method, based on the Loop Tree Duality, leads to locally integrable expressions in four dimensions. By introducing a physically motivated momentum mapping between the momenta involved in the real and the virtual contributions, infrared singularities naturally cancel at integrand level, without the need to introduce subtraction counter-terms. Ultraviolet singularities are dealt with by using dual representations of suitable counter-terms, with some subtleties regarding the self-energy contributions. As an example, we apply this method to compute the $1\to 2$ decay rate in the context of a scalar toy model with massive particles.

    hep-phhep-thAIP Conf.Proc.(2017)·3 citations
20. 20*

    Finite-volume effects on phase transition in the Polyakov-loop extended Nambu-Jona-Lasinio model with a chiral chemical potential

    Zan Pan🇨🇳 · Zhu-Fang Cui🇨🇳 · Chao-Hsi Chang🇨🇳 · Hong-Shi Zong🇨🇳

    To investigate finite-volume effects on the chiral symmetry restoration and the deconfinement transition and some impacts of possible global topological background for a quantum chromodynamics (QCD) system with $N_f=2$ (two quark flavors), we apply the Polyakov-loop extended Nambu-Jona-Lasinio model by introducing a chiral chemical potential ${\mu }_5$ artificially. The final numerical results indicate that the introduced chiral chemical potential does not change the critical exponents but shifts the location of critical end point (CEP) significantly; the ratios for the chiral chemical potentials and temperatures at CEP, ${\mu }_c/{\mu }_{5c}$ and $T_c/T_{5c}$, are significantly affected by the system size $R$. The behavior is that $T_c$ increases slowly with ${\mu }_5$ when $R$ is large and $T_c$ decreases first and then increases with ${\mu }_5$ when $R$ is small. It is also found that for a fixed ${\mu }_5$, there is a $R_{\text{min}}$, where the critical end point vanishes, and the whole phase diagram becomes a crossover when $R<R_{\text{min}}$. Therefore, we suggest that for the heavy-ion collision experiments, which is to study the possible location of CEP, the finite-volume behavior should be taken into account.

    hep-phhep-latInt.J.Mod.Phys.A(2017)·37 citations
21. 21*

    Chiral Symmetry restoration from the hadronic regime

    Angel Gomez Nicola🇪🇸 · Santiago Cortes🇨🇱 · John Morales🇨🇴 · Jacobo Ruiz de Elvira🇩🇪 · Ricardo Torres Andres🇪🇸

    We discuss recent advances on QCD chiral symmetry restoration at finite temperature, within the theoretical framework of Effective Theories. $U(3)$ Ward Identities are derived between pseudoscalar susceptibilities and quark condensates, allowing to explain the behaviour of lattice meson screening masses. Unitarized interactions and the generated $f_0(500)$ thermal state are showed to play an essential role in the description of the transition through the scalar susceptibility

    hep-phEPJ Web Conf.(2017)·1 citation
22. 22*

    Tension in the inclusive versus exclusive determinations of $|V_{cb}|$: a possible role of new physics

    Pietro Colangelo🇮🇹 · Fulvia De Fazio🇮🇹

    We reconsider the possibility that the tension in the $|V_{cb}|$ determinations from inclusive and exclusive $B$ decay modes is due to a new physics effect. We modify the Standard Model effective Hamiltonian for semileptonic $b\to c$ transitions including a tensor operator with a lepton flavour dependent coupling ${ϵ}_T^{\ell }$, and investigate separately the muon and electron modes. The interference term between SM and NP, proportional to the lepton mass, has different impact in the inclusive and exclusive $B$ modes to muon. Moreover, even when the lepton mass is small as for the electron, the NP effect is different in inclusive and exclusive $B$ channels. For both $\mu$ and $e$ we find a region of ${ϵ}_T^{\mu ,e}$ where the constraints from $B^{-}\to D^{(\ast )0}{\ell }^{-}{\bar{\nu }}_{\ell }$ and $B\to X_c\ell {\bar{\nu }}_{\ell }$ are satisfied for the same $|V_{cb}|$.

    hep-phhep-exPRD(2017)·63 citations
23. 23*

    Pair Production of Beyond the Standard Model Higgs Bosons

    Ramona Gröber🇬🇧

    Higgs pair production is not only sensitive to the trilinear Higgs self-coupling, but it can give access to other anomolous couplings, as e.g. a novel $hht\bar{t}$ coupling. In Composite Higgs Models, this coupling usually leads to a large increase of the cross section. In such a framework an interesting question is, whether it might be possible to observe new physics for the first time in Higgs pair production. This question will be addressed by taking into account projected sensitivities for Higgs coupling measurements and for direct searches of new vector-like quarks. Higher order corrections to Higgs pair production via gluon fusion are sizeable. It is hence not only important to compute them in the Standard Model (SM) but also in its extensions. Here, the computation of the QCD corrections in the SM with dimension 6 operators as well as the SUSY-QCD corrections to Higgs pair production via gluon fusion in the MSSM are presented.

    hep-phEPJ Web Conf.(2017)·3 citations
24. 24*

    Flavor origin of dark matter and its relation with leptonic nonzero ${\theta }_{13}$ and Dirac CP phase $\delta$

    Subhaditya Bhattacharya🇮🇳 · Biswajit Karmakar🇮🇳 · Narendra Sahu🇮🇳 · Arunansu Sil🇮🇳

    We propose a minimal extension of the standard model by including a $U(1)$ flavor symmetry to establish a correlation between the relic abundance of dark matter, measured by WMAP and PLANCK satellite experiments and non-zero value of $\sin {\theta }_{13}$ observed at DOUBLE CHOOZ, Daya Bay, RENO and T2K. The flavour symmetry is allowed to be broken at a high scale to a remnant ${\mathcal{Z}}_2$ symmetry, which not only ensures the stability to the dark matter, but also gives rise to a modification to the existing $A_4$-based tri-bimaximal neutrino mixing. This deviation in turn suggests the required non-zero value of $\sin {\theta }_{13}$. We assume the dark matter to be neutral under the existing $A_4$ symmetry while charged under the $U(1)$ flavor symmetry. Hence in this set-up, the non-zero value of $\sin {\theta }_{13}$ predicts the dark matter charge under $U(1)$, which can be tested at various ongoing and future direct and collider dark matter search experiments. We also point out the involvement of nonzero leptonic CP phase $\delta$, which plays an important role in the analysis.

    hep-phJHEP(2017)·38 citations
25. 25*

    Quark horizontal flavor symmetry and two-Higgs doublet in (7+1)-dimensional extended spin space

    R. Romero🇲🇽 · J. Besprosvany🇲🇽

    An extended spin-space model in $7+1$ dimensions is presented that describes the standard-model electroweak quark sector. Up to four generations of massless and massive quarks and two-Higgs doublets derive from the associated representation space, in addition to the W- and Z-vector bosons. Other mass operators are obtained that put restrictions on additional non-Higgs scalars and their vacuum expectation value. After symmetry breaking, the scalar components give rise to a hierarchy effect vertically (within doublets) associated to the Higgs fields, and horizontally (within generations) associated to the non-Higgs elements.

    hep-ph2 citations
26. 26*

    Field induced phase transition in the few photon regime

    A. D. Panferov🇷🇺 · S. A. Smolyansky🇷🇺 · A. I. Titov🇷🇺 · B. Kaempfer🇩🇪 · A. Otto🇩🇪 · D. B. Blaschke🇷🇺 · L. Juchnowski🇵🇱

    Some features of the field induced phase transition accompanied by the vacuum creation of an electron-positron plasma (EPP) in strong time-dependent electric fields have been discussed in the work [1] in the domain of the tunneling mechanism ($\omega \ll m$, where $\omega$ is the characteristic frequency of the external field and $m$ is the electron mass). In the present contribution the features of the this process will be considered in the few photon domain where $\omega \sim m$. We observe a narrowing of the transient domain of the fast oscillations and, mainly, a considerable growth of the effectiveness of the EPP production. Under these circumstances, we see an increase of the effectiveness of the EPP creation in the particular case of a bifrequent excitation, where both mechanisms (tunneling and few photon) act simultaneously [2,3].

    ↳ physics.plasm-phhep-phEPJ Web Conf.(2017)·2 citations
27. 27*

    Testing Quantum Black Holes with Gravitational Waves

    Valentino F. Foit🇺🇸 · Matthew Kleban🇺🇸

    We argue that near-future detections of gravitational waves from merging black hole binaries can test a long-standing proposal, originally due Bekenstein and Mukhanov, that the areas of black hole horizons are quantized in integer multiples of the Planck area times an $\mathcal{O}(1)$ dimensionless constant $\alpha$. This condition quantizes the frequency of radiation that can be absorbed or emitted by a black hole. If this quantization applies to the "ring down" gravitational radiation emitted immediately after a black hole merger, a single measurement consistent with the predictions of classical general relativity would rule out most or all (depending on the spin of the hole) of the extant proposals in the literature for the value of $\alpha$. A measurement of two such events for final black holes with substantially different spins would rule out the proposal for any $\alpha$. If the modification of general relativity is confined to the near-horizon region within the hole's light ring and does not affect the initial ring down signal, a detection of "echoes" with characteristic properties could still confirm the proposal.

    ↳ hep-thastro-ph.HEgr-qchep-phClass.Quant.Grav.(2019)·58 citations
28. 28*

    Universality in generalized models of inflation

    Pierre Binétruy🇫🇷 · Joel Mabillard🇬🇧 · Mauro Pieroni🇫🇷

    We discuss the cosmological evolution of a scalar field with non standard kinetic term in terms of a Renormalization Group Equation (RGE). In this framework inflation corresponds to the slow evolution in a neighborhood of a fixed point and universality classes for inflationary models naturally arise. Using some examples we show the application of the formalism. The predicted values for the speed of sound $c_s$ and for the amount of non-Gaussianities produced in these models are discussed. In particular, we show that it is possible to introduce models with $c_s^2\ne 1$ that can be in agreement with present cosmological observations.

    ↳ gr-qcastro-ph.COhep-phJCAP(2017)·20 citations
29. 29*

    Small Vacuum Energy from Small Equivalence Violation in Scalar Gravity

    Prateek Agrawal🇺🇸 · Raman Sundrum🇺🇸

    The theory of scalar gravity proposed by Nordström, and refined by Einstein and Fokker, provides a striking analogy to general relativity. In its modern form, scalar gravity appears as the low-energy effective field theory of the spontaneous breaking of conformal symmetry within a CFT, and is AdS/CFT dual to the original Randall-Sundrum I model, but without a UV brane. Scalar gravity faithfully exhibits several qualitative features of the cosmological constant problem of standard gravity coupled to quantum matter, and the Weinberg no-go theorem can be extended to this case as well. Remarkably, a solution to the scalar gravity cosmological constant problem has been proposed, where the key is a very small violation of the scalar equivalence principle, which can be elegantly formulated as a particular type of deformation of the CFT. In the dual AdS picture this involves implementing Goldberger-Wise radion stabilization where the Goldberger-Wise field is a pseudo-Nambu Goldstone boson. In quantum gravity however, global symmetries protecting pNGBs are not expected to be fundamental. We provide a natural six-dimensional gauge theory origin for this global symmetry and show that the violation of the equivalence principle and the size of the vacuum energy seen by scalar gravity can naturally be exponentially small. Our solution may be of interest for study of non-supersymmetric CFTs in the spontaneously broken phase.

    ↳ hep-thgr-qchep-phJHEP(2017)·11 citations
30. 30*

    A mild source for the Wu-Yang magnetic monopole

    C. P. Constantinidis🇧🇷 · L. A. Ferreira🇧🇷 · G. Luchini🇧🇷

    We establish that the Wu-Yang monopole needs the introduction of a magnetic point source at the origin in order for it to be a solution of the differential and integral equations for the Yang-Mills theory. That result is corroborated by the analysis through distribution theory, of the two types of magnetic fields relevant for the local and global properties of the Wu-Yang solution. The subtlety lies on the fact that with the non-vanishing magnetic point source required by the Yang-Mills integral equations, the Wu-Yang monopole configuration does not violate, in the sense of distribution theory, the differential Bianchi identity.

    ↳ hep-thhep-phmath-phmath.MPJ.Phys.A(2019)·6 citations
31. 31*

    Effects of Induced Surface Tension in Nuclear and Hadron Matter

    V.V. Sagun🇺🇦 · K.A. Bugaiev🇺🇦 · A.I. Ivanytskyi🇺🇦 · D.R. Oliinychenko🇺🇦 · I.N. Mishustin🇩🇪

    Short range particle repulsion is rather important property of the hadronic and nuclear matter equations of state. We present a novel equation of state which is based on the virial expansion for the multicomponent mixtures with hard-core repulsion. In addition to the hard-core repulsion taken into account by the proper volumes of particles, this equation of state explicitly contains the surface tension which is induced by another part of the hard-core repulsion between particles. At high densities the induced surface tension vanishes and the excluded volume treatment of hard-core repulsion is switched to its proper volume treatment. Possible applications of this equation of state to a description of hadronic multiplicities measured in A+A collisions, to an investigation of the nuclear matter phase diagram properties and to the neutron star interior modeling are discussed.

    ↳ nucl-thastro-ph.HEhep-phEPJ Web Conf.(2017)·13 citations
32. 32*

    Path-integral formula for local thermal equilibrium

    Masaru Hongo🇯🇵

    We develop a complete path-integral formulation of relativistic quantum fields in local thermal equilibrium, which brings about the emergence of thermally induced curved spacetime. The resulting action is shown to have full diffeomorphism invariance and gauge invariance in thermal spacetime with imaginary-time independent backgrounds. This leads to the notable symmetry properties of emergent thermal spacetime: Kaluza-Klein gauge symmetry, spatial diffeomorphism symmetry, and gauge symmetry. A thermodynamic potential in local thermal equilibrium, or the so-called Masseiu-Planck functional, is identified as a generating functional for conserved currents such as the energy-momentum tensor and the electric current.

    ↳ hep-thcond-mat.quant-gascond-mat.stat-mechhep-ph+1Annals Phys.(2017)·36 citations
33. 33*

    Higgs-otic Inflation and Moduli Stabilization

    Sjoerd Bielleman🇪🇸 · Luis E. Ibanez🇪🇸 · Francisco G. Pedro🇪🇸 · Irene Valenzuela🇩🇪 · Clemens Wieck🇪🇸

    We study closed-string moduli stabilization in Higgs-otic inflation in Type IIB orientifold backgrounds with fluxes. In this setup large-field inflation is driven by the vacuum energy of mobile D7-branes. Imaginary selfdual (ISD) three-form fluxes in the background source a $\mu$-term and the necessary monodromy for large field excursions while imaginary anti-selfdual (IASD) three-form fluxes are sourced by non-perturbative contributions to the superpotential necessary for moduli stabilization. We analyze Kähler moduli stabilization and backreaction on the inflaton potential in detail. Confirming results in the recent literature, we find that integrating out heavy Kähler moduli leads to a controlled flattening of the inflaton potential. We quantify the flux tuning necessary for stability even during large-field inflation. Moreover, we study the backreaction of supersymmetrically stabilized complex structure moduli and the axio-dilaton in the Kähler metric of the inflaton. Contrary to previous findings, this backreaction can be pushed far out in field space if a similar flux tuning as in the Kähler sector is possible. This allows for a trans-Planckian field range large enough to support inflation.

    ↳ hep-thastro-ph.COhep-phJHEP(2017)·35 citations
34. 34*

    Search for the $0^{--}$ Glueball in ${\rm Y}(1S)$ and ${\rm Y}(2S)$ decays

    Belle Collaboration: S. Jia · C. P. Shen · C. Z. Yuan · I. Adachi · H. Aihara · S. Al Said · D. M. Asner · T. Aushev · R. Ayad · V. Babu · I. Badhrees · A. M. Bakich and 158 other authors

    We report the first search for the $J^{PC}=0^{--}$ glueball in ${\rm Y}(1S)$ and ${\rm Y}(2S)$ decays with data samples of $(102\pm 2)$ million and $(158\pm 4)$ million events, respectively, collected with the Belle detector. No significant signals are observed in any of the proposed production modes, and the 90\% credibility level upper limits on their branching fractions in ${\rm Y}(1S)$ and ${\rm Y}(2S)$ decays are obtained. The inclusive branching fractions of the ${\rm Y}(1S)$ and ${\rm Y}(2S)$ decays into final states with a ${\chi }_{c1}$ are measured to be $\text{BR}({\rm Y}(1S)\to {\chi }_{c1}+anything)=(1.90\pm 0.43(stat.)\pm 0.14(syst.))\times 10^{-4}$ with an improved precision over prior measurements and $\text{BR}({\rm Y}(2S)\to {\chi }_{c1}+anything)=(2.24\pm 0.44(stat.)\pm 0.20(syst.))\times 10^{-4}$ for the first time.

    ↳ hep-exhep-phPRD(2017)·19 citations
35. 35*

    Ultra High Energy Cosmic Rays & Super-heavy Dark Matter

    Luca Marzola🇪🇪 · Federico R Urban🇪🇪

    We reanalyse the prospects for upcoming Ultra-High Energy Cosmic Ray experiments in connection with the phenomenology of Super-heavy Dark Matter. We identify a set of observables well suited to reveal a possible anisotropy in the High Energy Cosmic Ray flux induced by the decays of these particles, and quantify their performance via Monte Carlo simulations that mimic the outcome of near-future and next-generation experiments. The spherical and circular dipoles are able to tell isotropic and anisotropic fluxes apart at a confidence level as large as $4\sigma$ or $5\sigma$, depending on the Dark Matter profile. The forward-to-backward flux ratio yields a comparable result for relatively large opening angles of about 40~deg, but it is less performing once a very large number of events is considered. We also find that an actual experiment employing these observables and collecting 300~events at 60~EeV would have a $50\%$ chance of excluding isotropy against Super-heavy Dark Matter at a significance of at least $3\sigma$

    ↳ astro-ph.HEastro-ph.COhep-phAstropart.Phys.(2017)·13 citations
36. 36*

    Volume reduction through perturbative Wilson loops

    Margarita Garcia Perez🇪🇸 · Antonio Gonzalez-Arroyo🇪🇸 · Masanori Okawa🇯🇵

    We derive the perturbative expansion of Wilson loops to order g^4 in a SU(N) lattice gauge theory with twisted boundary conditions. Our expressions show that the thermodynamic limit is attained at infinite N for any number of lattice sites and allow to quantify the deviations from volume independence at finite large N as a function of the twist.

    ↳ hep-lathep-phhep-thPoS(2016)·3 citations
37. 37*

    Heavy neutrino searches from MeV to TeV

    Elena Graverini🇨🇭

    The Standard Model (SM) describes particle physics with great precision. However, it does not account for the generation of neutrino masses, whose nature we do not understand. Both a Dirac and a Majorana mass term could intervene, leading to the existence of heavy partners of the SM neutrinos, presumably more massive and nearly sterile. For suitable choices of parameters, heavy neutrinos can also provide dark matter candidates, and generate the observed baryon asymmetry of the universe. Heavy neutrinos can be searched for at beam dump facilities such as the proposed SHiP experiment if their mass is of the order of few GeV, or at high energy lepton colliders, such as the Future $e^{+}{e}^{-}$ Circular Collider, FCC-ee, presently under study at CERN, for higher masses. This contribution presents a review of the sensitivities for heavy neutrino searches at SHiP and FCC-ee.

    ↳ hep-exhep-ph3 citations
38. 38*

    Perturbative running of the twisted Yang-Mills coupling in the gradient flow scheme

    Eduardo I. Bribian🇪🇸 · Margarita Garcia Perez🇪🇸

    We report on our ongoing computation of the perturbative running of the Yang-Mills coupling using gradient flow techniques. In particular, we use the gradient flow method with twisted boundary conditions to perform a perturbative expansion of the expectation value of the Yang-Mills energy density up to fourth order in the coupling at finite flow time. We regularise the resulting integrals using dimensional regularisation, and reproduce the universal coefficient of the 1/{\epsilon} term in the relation between bare and renormalised couplings. The computation of the finite part leading to a determination of the {\Lambda} parameter in this scheme is underway.

    ↳ hep-lathep-phhep-thPoS(2016)·3 citations
39. 39*

    New results for a two-loop massless propagator-type Feynman diagram

    A. V. Kotikov🇷🇺 · S. Teber🇫🇷

    We consider the two-loop massless propagator-type Feynman diagram with an arbitrary (non-integer) index on the central line. We analytically prove the equality of the two well-known results existing in the literature which express this diagram in terms of ${}_3{F}_2$-hypergeometric functions of argument $-1$ and $1$, respectively. We also derive new representations for this diagram which may be of importance in practical calculations.

    ↳ hep-thcond-mat.mes-hallhep-phmath-ph+1Teor.Mat.Fiz.(2018)·9 citations
40. 40*

    Pomeron-Odderon Interactions: A Functional RG Flow Analysis

    Gian Paolo Vacca🇮🇹

    In the quest for an effective field theory which could help to understand some non perturbative feature of the QCD in the Regge limit, we consider a Reggeon Field Theory (RFT) for both Pomeron and Odderon interactions and perform an analysys of the critical theory using functional renormalization group techniques, unveiling a novel symmetry structure.

    ↳ hep-thhep-phAIP Conf.Proc.(2017)·3 citations
41. 41*

    Constraints on Scalar-Pseudoscalar and Tensorial Non-Standard Interaction and Tensorial Unparticle Couplings from Neutrino-Electron Scattering

    M. Deniz · B. Sevda · S. Kerman · A. Ajjaq · L. Singh · H.T. Wong · M. Zeyrek

    Neutrino-electron scattering is a purely leptonic fundamental interaction and therefore provides an important channel to test the Standard Model, especially at the low energy-momentum transfer regime. We derived constraints on neutrino nonstardard interaction couplings depending on model-independent approaches which are described by a four-Fermi pointlike interaction and unparticle physics model with tensorial components. Data on ${\bar{\nu }}_e-e$ and ${\nu }_e-e$ scattering from the TEXONO and LSND experiments, respectively, are used. The upper limits and the allowed regions of scalar, pseudoscalar, and tensorial nonstandard interaction couplings of neutrinos are derived at 90\% confidence level in both one-parameter and two-parameter analysis. New upper limits for tensorial unparticle physics coupling constants and mass parameters are also placed.

    ↳ hep-exhep-phPRD(2017)·17 citations
42. 42*

    A numerical study of non-perturbative corrections to the Chiral Separation Effect in quenched finite-density QCD

    M. Puhr🇩🇪 · P. V. Buividovich🇩🇪

    We demonstrate the non-renormalization of the Chiral Separation Effect (CSE) in quenched finite-density QCD in both confinement and deconfinement phases using a recently developed numerical method which allows, for the first time, to address the transport properties of exactly chiral, dense lattice fermions. This finding suggests that CSE can be used to fix renormalization constants for axial current density. Explaining the suppression of the CSE which we observe for topologically nontrivial gauge field configurations on small lattices, we also argue that CSE vanishes for self-dual non-Abelian fields inside instanton cores.

    ↳ hep-lathep-phhep-thPRL(2017)·27 citations
43. 43*

    On Nambu's Fermion-Boson Relations for Superfluid ${}^3$He-B

    J. A. Sauls · Takeshi Mizushima🇯🇵

    Superfluid ${}^3$He is a spin-triplet ($S=1$), p-wave ($L=1$) BCS condensate of Cooper pairs with total angular momentum $J=0$ in the ground state. In addition to the breaking of $U(1)$ gauge symmetry, separate spin or orbital rotation symmetry is broken to the maximal sub-group, $SO(3{)}_S\times SO(3{)}_L\to SO(3{)}_J$. The Fermions acquire mass, $m_F\equiv \Delta$, where $\Delta$ is the BCS gap. There are also 18 Bosonic excitations - 4 Nambu-Goldstone (NG) modes and 14 massive amplitude Higgs (AH) modes. The Bosonic modes are labelled by the total angular momentum, $J\in \{0,1,2\}$, and parity under particle-hole symmetry, $C=\pm 1$. For each pair of angular momentum quantum numbers, $J,J_z$, there are two Bosonic partners with $C=\pm 1$. Based this spectrum Nambu proposed a sum rule connecting the Fermion and Boson masses for BCS type theories, which for ${}^3$He-B is $M_{J^{+}}^2+M_{J^{-}}^2=4m_F^2$ for each family of Bosonic modes labelled by $J$, where $M_{J^C}$ is the mass of the Bosonic mode with quantum numbers $(J,C)$. Nambu's sum rule (NSR) has recently been discussed in the context of Nambu-Jona-Lasinio models for physics beyond the standard model to speculate on possible partners to the recently discovered Higgs Boson at higher energies. Here we point out that Nambu's Fermion-Boson mass relations are not exact. Corrections to the Bosonic masses from (i) leading order strong-coupling corrections to BCS theory, and (ii) polarization of the parent Fermionic vacuum lead to violations of the sum-rule. Results for these mass corrections are given in both the $T\to 0$ and $T\to T_c$ limits. We also discuss experimental results, and theoretical analysis, for the masses of the $J^C=2^{\pm }$ Higgs modes and the magnitude of the violation of the NSR.

    ↳ cond-mat.supr-conhep-phPRB(2017)·15 citations
44. 44*

    Forward-backward correlations between intensive observables

    Vladimir Kovalenko🇷🇺 · Vladimir Vechernin (Saint Petersburg State University, Russia)🇷🇺

    We demonstrate that the investigations of the forward-backward correlations between intensive observables enable to obtain more clear signal about the initial stage of hadronic interaction, e.g. about the process of string fusion, compared to usual forward-backward multiplicity correlations. As an example, the correlation between mean-event transverse momenta of charged particles in separated rapidity intervals is considered. We performed calculations in the framework of dipole-based Monte Carlo string fusion model. We obtained the dependence of the correlation strength on the collision centrality for different initial energies and colliding systems. It is shown that the dependence reveals the decline of the correlation coefficient for most central Pb-Pb collisions at LHC energy. We compare the results both with the ones obtained in alternative models and with the ones obtained by us using various MC generators.

    ↳ nucl-thhep-phJ.Phys.Conf.Ser.(2017)·12 citations
45. 45*

    Resonances in Coupled-Channel Scattering

    David J. Wilson🇬🇧

    Excited hadrons are seen as resonances in the scattering of lighter stable hadrons like $\pi$, $K$ and $\eta$. Many decay into multiple final states necessitating coupled-channel analyses. Recently it has become possible to obtain coupled-channel scattering amplitudes from lattice QCD. Using large diverse bases of operators it is possible to obtain reliable finite volume spectra at energies where multiple channels are open. Utilising the finite volume formalism proposed by Lüscher and extended by several others, scattering amplitudes can be extracted from the finite volume spectra. Recent applications will be discussed where the energy dependence of scattering amplitudes is mapped out in several quantum numbers. These are then continued to complex energies to extract resonance poles and couplings.

    ↳ hep-lathep-phPoS(2016)·8 citations
46. 46*

    Fermi/non-Fermi mixing in SU($N$) Kondo effect

    Taro Kimura🇯🇵 · Sho Ozaki🇯🇵

    We apply conformal field theory analysis to the $k$-channel SU($N$) Kondo system, and find a peculiar behavior in the cases $N>k>1$, which we call Fermi/non-Fermi mixing: The low temperature scaling is described as the Fermi liquid, while the zero temperature IR fixed point exhibits the non-Fermi liquid signature. We also show that the Wilson ratio is no longer universal for the cases $N>k>1$. The deviation from the universal value of the Wilson ratio could be used as an experimental signal of the Fermi/non-Fermi mixing.

    ↳ cond-mat.str-elhep-phhep-thJ.Phys.Soc.Jap.(2017)·26 citations
47. 47*

    Sub-millimeter Spatial Oscillations of Newton's Constant: Theoretical Models and Laboratory Tests

    Leandros Perivolaropoulos🇬🇷

    We investigate the viability of sub-millimeter wavelength oscillating deviations from the Newtonian potential at both the theoretical and the experimental/observational level. At the theoretical level such deviations are generic predictions in a wide range of extensions of General Relativity (GR) including $f(R)$ theories, massive Brans-Dicke theories, compactified extra dimension models and nonlocal extensions of GR. However, the range of parameters associated with such oscillating deviations is usually connected with instabilities. An exception emerges in nonlocal gravity theories where oscillating deviations from Newtonian potential occur naturally on sub-millimeter scales without instabilities. As an example of a model with unstable Newtonian oscillations we review an $f(R)$ expansion around General Relativity of the form $f(R)=R+\frac{1}{6m^2}{R}^2$ with $m^2<0$ pointing out possible stabilization mechanisms. As an example of a model with stable Newtonian oscillations we discuss nonlocal gravity theories. If such oscillations are realized in Nature on sub-millimeter scales, a signature is expected in torsion balance experiments testing Newton's law. We search for such a signature in the torsion balance data of the Washington experiment (combined torque residuals) testing Newton's law at sub-millimeter scales. We show that an oscillating residual ansatz with spatial wavelength $\lambda \simeq 0.1mm$ provides a better fit to the data compared to the residual Newtonian constant ansatz by $\Delta {\chi }^2=-15$. Similar improved fits, also occur in about $10\%$ of Monte Carlo realizations of Newtonian data. Thus, the significance level of this improved fit is at a level of not more than $2\sigma$. The energy scale corresponding to this best fit wavelength is identical to the dark energy length scale ${\lambda }_{de}\equiv \sqrt[4]{\hslash c/{\rho }_{de}}\approx 0.1mm$.

    ↳ gr-qcastro-ph.COhep-exhep-ph+1PRD(2017)·51 citations
48. 48*

    Decay constants $f_B$ and $f_{B_s}$ and quark masses $m_b$ and $m_c$ from HISQ simulations

    J. Komijani🇩🇪 · A. Bazavov🇺🇸 · C. Bernard🇺🇸 · N. Brambilla🇩🇪 · N. Brown🇺🇸 · C. DeTar🇺🇸 · D. Du🇺🇸 · A.X. El-Khadra🇺🇸 · E.D. Freeland🇺🇸 · E. Gámiz🇪🇸 · Steven Gottlieb🇺🇸 · U.M. Heller🇺🇸 and 11 other authors

    We present a progress report on our calculation of the decay constants $f_B$ and $f_{B_s}$ from lattice-QCD simulations with highly-improved staggered quarks. Simulations are carried out with several heavy valence-quark masses on $(2+1+1)$-flavor ensembles that include charm sea quarks. We include data at six lattice spacings and several light sea-quark masses, including an approximately physical-mass ensemble at all but the smallest lattice spacing, 0.03 fm. This range of parameters provides excellent control of the continuum extrapolation to zero lattice spacing and of heavy-quark discretization errors. Finally, using the heavy-quark effective theory expansion we present a method of extracting from the same correlation functions the charm- and bottom-quark masses as well as some low-energy constants appearing in the heavy-quark expansion.

    ↳ hep-lathep-phPoS(2016)·5 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.