Thu·Jan 5, 2017Thursday·January 5, 2017

1. 01*

   Electromagnetic axial anomaly in a generalized linear sigma model

   Amir H. Fariborz🇺🇸 · Renata Jora🇷🇴

   We construct the electromagnetic anomaly effective term for a generalized linear sigma model with two chiral nonets, one with a quark-antiquark structure, the other one with a four quark content. We compute in the leading order of this framework the decays into two photons of six pseudoscalars: ${\pi }_0(137)$, ${\pi }_0(1300)$, $\eta (547)$, $\eta (958)$, $\eta (1295)$ and $\eta (1760)$. Our results agree well with the available experimental data.

   hep-phPRD(2017)·11 citations
2. 02*

   Sgoldstino search at the LHC

   Masaki Asano🇩🇪 · Raghuveer Garani🇩🇪

   Low-scale supersymmetry breaking scenario in which the breaking scale is around TeV has been discussed as a possibility to obtain a large Higgs mass and to moderate the fine tuning problem. A characteristic feature is that the hidden sector would be accessible at colliders in such a scenario. In this paper, we investigate the phenomenology of sgoldstino which is the scalar component of the goldstino superfield. We present partial widths and branching ratios for sgoldstinos decaying to final states involving Higgs bosons and sparticles which have not been discussed in detail so far.

   hep-ph4 citations
3. 03*

   Prospects for new physics in $\tau \to l\mu \mu$ at current and future colliders

   Chris Hays🇬🇧 · Manimala Mitra🇮🇳 · Michael Spannowsky🇬🇧 · Philip Waite🇬🇧

   The discovery of lepton flavour violating interactions will be striking evidence for physics beyond the Standard Model. Focusing on the three decays ${\tau }^{\mp }\to {\mu }^{\pm }{\mu }^{\mp }{\mu }^{\mp }$, ${\tau }^{\mp }\to e^{\pm }{\mu }^{\mp }{\mu }^{\mp }$ and ${\tau }^{\mp }\to e^{\mp }{\mu }^{\mp }{\mu }^{\pm }$, we evaluate the discovery potential of current and future high-energy colliders to probe lepton flavour violation in the $\tau$ sector. Based on this potential we determine the expected constraints on parameters of new physics in the context of the Type-II Seesaw Model, the Left-Right Symmetric Model, and the Minimal Supersymmetric Standard Model. The existing and ongoing 13 TeV run of the Large Hadron Collider has the potential to produce constraints that outperform the existing $e^{+}{e}^{-}$ collider limits for the ${\tau }^{\mp }\to {\mu }^{\pm }{\mu }^{\mp }{\mu }^{\mp }$ decay and achieve a branching fraction limit of $\lesssim 10^{-8}$. With a future circular $e^{+}{e}^{-}$ collider, constraints on the $\tau \to l\mu \mu$ branching fractions could reach as low as a few times $10^{-12}$.

   hep-phhep-exJHEP(2017)·15 citations
4. 04*

   Exploring the ${\rm Y}(6S)\to {\chi }_{bJ}\varphi$ and ${\rm Y}(6S)\to {\chi }_{bJ}\omega$ hidden-bottom hadronic transitions

   Qi Huang🇨🇳 · Bo Wang🇨🇳 · Xiang Liu🇨🇳 · Dian-Yong Chen🇨🇳 · Takayuki Matsuki🇯🇵

   In this work, we investigate the hadronic loop contributions to the ${\rm Y}(6S)\to {\chi }_{bJ}\varphi (J=0,1,2)$ along with ${\rm Y}(6S)\to {\chi }_{bJ}\omega (J=0,1,2)$ transitions. We predict that the branching ratios of ${\rm Y}(6S)\to {\chi }_{b0}\varphi$, ${\rm Y}(6S)\to {\chi }_{b1}\varphi$ and ${\rm Y}(6S)\to {\chi }_{b2}\varphi$ are $(0.68\sim 4.62)\times 10^{-6}$, $(0.50\sim 3.43)\times 10^{-6}$ and $(2.22\sim 15.18)\times 10^{-6}$, respectively and those of ${\rm Y}(6S)\to {\chi }_{b0}\omega$, ${\rm Y}(6S)\to {\chi }_{b1}\omega$ and ${\rm Y}(6S)\to {\chi }_{b2}\omega$ are $(0.15\sim 2.81)\times 10^{-3}$, $(0.63\sim 11.68)\times 10^{-3}$ and $(1.08\sim 20.02)\times 10^{-3}$, respectively. Especially, some typical ratios, which reflect the relative magnitudes of the predicted branching ratios, are given, i.e., for ${\rm Y}(6S)\to {\chi }_{bJ}\varphi$ transitions, ${\mathcal{R}}_{10}^{\varphi }=\mathcal{B}[{\rm Y}(6S)\to {\chi }_{b1}\varphi ]/\mathcal{B}[{\rm Y}(6S)\to {\chi }_{b0}\varphi ]\approx 0.74$, ${\mathcal{R}}_{20}^{\varphi }=\mathcal{B}[{\rm Y}(6S)\to {\chi }_{b2}\varphi ]/\mathcal{B}[{\rm Y}(6S)\to {\chi }_{b0}\varphi ]\approx 3.28$, and ${\mathcal{R}}_{21}^{\varphi }=\mathcal{B}[{\rm Y}(6S)\to {\chi }_{b2}\varphi ]/\mathcal{B}[{\rm Y}(6S)\to {\chi }_{b1}\varphi ]\approx 4.43$, and for ${\rm Y}(6S)\to {\chi }_{bJ}\omega$ transitions, ${\mathcal{R}}_{10}^{\omega }=\mathcal{B}[{\rm Y}(6S)\to {\chi }_{b1}\omega ]/\mathcal{B}[{\rm Y}(6S)\to {\chi }_{b0}\omega ]\approx 4.11$, ${\mathcal{R}}_{20}^{\omega }=\mathcal{B}[{\rm Y}(6S)\to {\chi }_{b2}\omega ]/\mathcal{B}[{\rm Y}(6S)\to {\chi }_{b0}\omega ]\approx 7.06$, and ${\mathcal{R}}_{21}^{\omega }=\mathcal{B}[{\rm Y}(6S)\to {\chi }_{b2}\omega ]/\mathcal{B}[{\rm Y}(6S)\to {\chi }_{b1}\omega ]\approx 1.72$. With the running of BelleII in the near future, experimental measurement of these two kinds of transitions will be a potential research issue.

   hep-phhep-exEPJC(2017)·19 citations
5. 05*

   Probing Lepton Flavor Violation Signal via \gamma\gamma\to l_i\barl_j in the Left-Right Twin Higgs Model at the ILC

   Guo-Li Liu🇨🇳 · Fei Wang🇨🇳 · Kuan Xie🇨🇳 · Xiao-Fei Guo🇨🇳

   To explain the small neutrino masses, heavy Majorana neutrinos are introduced in the left-right twin Higgs model. The heavy neutrinos, together with the charged scalars and the heavy gauge bosons, may contribute large mixings between the neutrinos and the charged leptons, which may induce some distinct lepton flavor violating processes. We will check the \bar \ell_i \ell_j (i,j= e,\mu,\tau,i\neq j) productions in the \gamma\gamma collision in the left-right twin Higgs model, and find that the production rates may be large in some specific parameter space, in the optimal cases even possible to be detected with reasonable kinematical cuts. we have also shown that these collisions can constrain effectively the model parameters such as the Higgs vacuum expectation value and the right-handed neutrino mass, etc., and may serve as a sensitive probe of this new physics model.

   hep-phPRD(2017)·5 citations
6. 06*

   Is the colour-octet mechanism consistent with the double $J/\psi$ production measurement at B-factories?

   Yu Feng🇨🇳 · Zhan Sun🇨🇳 · Hong-Fei Zhang🇨🇳

   Double $J/\psi$ production in $e^{+}{e}^{-}$ collisions involving colour-octet channels are evaluated up to order ${\alpha }^2{\alpha }_s^3$. Having implemented the variation of the parameters ($m_c$, ${\mu }_r$ and long-distance matrix elements), we found that the cross sections for producing double $J/\psi$ at B-factories range from $-0.016$fb to $0.245$fb, which are even much smaller than that via the colour-siglet mechanism. Accordingly, this result is consistent with the measurement by the Belle and BABAR Collaborations.

   hep-phEPJC(2017)·8 citations
7. 07*

   Baryons with functional methods

   Christian S. Fischer🇩🇪

   We summarise recent results on the spectrum of ground-state and excited baryons and their form factors in the framework of functional methods. As an improvement upon similar approaches we explicitly take into account the underlying momentum-dependent dynamics of the quark-gluon interaction that leads to dynamical chiral symmetry breaking. For light octet and decuplet baryons we find a spectrum in very good agreement with experiment, including the level ordering between the positive- and negative-parity nucleon states. Comparing the three-body framework with the quark-diquark approximation, we do not find significant differences in the spectrum for those states that have been calculated in both frameworks. This situation is different in the electromagnetic form factor of the $\Delta$, which may serve to distinguish both pictures by comparison with experiment and lattice QCD.

   hep-phEPJ Web Conf.(2017)·0 citations
8. 08*

   Pulse shape effects on the electron-positron pair production in strong laser fields

   I. A. Aleksandrov🇷🇺 · G. Plunien🇩🇪 · V. M. Shabaev🇷🇺

   The pair-production process in the presence of strong linearly polarized laser fields with a subcycle structure is considered. Laser pulses with different envelope shapes are examined by means of a nonperturbative numerical technique. We analyze two different "flat" envelope shapes and two shapes without a plateau for their various parameters including the carrier-envelope phase. The resonant Rabi oscillations, momentum distribution of particles created, and total number of pairs are studied. It is demonstrated that all these characteristics are very sensitive to the pulse shape.

   hep-phhep-thphysics.atom-phPRD(2017)·34 citations
9. 09*

   A Three-loop Neutrino Model with Leptoquark Triplet Scalars

   Kingman Cheung🇹🇼 · Takaaki Nomura🇰🇷 · Hiroshi Okada🇹🇼

   We propose a three-loop neutrino mass model with a few leptoquark scalars in $SU(2{)}_L$-triplet form, through which we can explain the anomaly of $B\to K^{(\ast )}{\mu }^{+}{\mu }^{-}$, a sizable muon $g-2$ and a bosonic dark matter candidate, and at the same time satisfying all the constraints from lepton flavor violations. We perform global numerical analyses and show the allowed regions, in which we find somewhat restricted parameter space, such as the mass of dark matter candidate and various components of the Yukawa couplings in the model.

   hep-phPLB(2017)·22 citations
10. 10*

    Review of QCD, QGP, Heavy Quark Meson Production Enhancement and Suppression

    Leonard S. Kisslinger🇺🇸

    This review of the Quantum Chromodynamics (QCD),the early universe Cosmoloical Phase Transition from the Quark-Gluon Plasma (QGP) to our present universe (QCDPT), Relativistic Heavy Ion Collisions (RHIC) which can produce the QGP, the possible detection of the QGP produced by the production of mixed hybrid heavy quark mesons. We also review recent studies of the production of mixed heavy quark hybrids via RHIC and heavy quark meson supression in p-Pb and Pb-Pb collisions.

    hep-phInt.J.Mod.Phys.A(2017)·4 citations
11. 11*

    Simple chromatic properties of gradient flow

    Thomas DeGrand🇺🇸

    It has become customary to use a smoothing algorithm called "gradient flow" to fix the lattice spacing in a simulation, through a parameter called $t_0$. It is shown that in order to keep the length $t_0$ fixed with respect to mesonic or gluonic observables as the number of colors $N_c$ is varied, the fiducial point for the flow parameter must be scaled nearly linearly in $N_c$. In simulations with dynamical fermions, the dependence of $t_0$ on the pseudoscalar meson mass flattens as the number of colors rises, in a way which is consistent with large $N_c$ expectations.

    ↳ hep-lathep-phPRD(2017)·18 citations
12. 12*

    Hyperon polarization in Heavy-Ion Collisions and gravity-related anomaly

    Mircea Baznat🇷🇺 · Konstantin Gudima🇲🇩 · Alexander Sorin🇷🇺 · Oleg Teryaev🇷🇺

    We study the energy dependence of global polarization of $\Lambda$ hyperons in peripheral $Au-Au$ collisions. We combine the calculation of vorticity and strange chemical potential in the framework of kinetic Quark-Gluon String Model with the anomalous mechanism related to axial vortical effect. The earlier found effect of helicity separation implies the quadrupole structure of longitudinal vorticity. We pay special attention to the temperature dependent contribution related to gravitational anomaly and found that the preliminary RHIC data are compatible with its suppression discovered earlier in lattice calculations. The antihyperons polarization is excessing that of hyperons and the difference is more pronounced at smaller energies.

    ↳ nucl-thhep-lathep-phPRC(2018)·73 citations
13. 13*

    MultivariateResidues: a Mathematica package for computing multivariate residues

    Kasper J. Larsen🇬🇧 · Robbert Rietkerk🇩🇪

    Multivariate residues appear in many different contexts in theoretical physics and algebraic geometry. In theoretical physics, they for example give the proper definition of generalized-unitarity cuts, and they play a central role in the Grassmannian formulation of the S-matrix by Arkani-Hamed et al. In realistic cases their evaluation can be non-trivial. In this paper we provide a Mathematica package for efficient evaluation of multidimensional residues based on methods from computational algebraic geometry. The package moreover contains an implementation of the global residue theorem, which produces relations between residues at finite locations and residues at infinity.

    ↳ hep-thhep-phmath.AGComput.Phys.Commun.(2018)·28 citations
14. 14*

    Dirac and Weyl fermions: from Gor'kov equations to Standard Model (in memory of Lev Petrovich Gorkov)

    G.E. Volovik🇫🇮

    Gor'kov theory of superconductivity opened the application of the methods of quantum field theory to condensed matter physics. Later the results became relevant to relativistic quantum fields.

    ↳ cond-mat.supr-conhep-phJETP Lett.(2017)·8 citations
15. 15*

    Testing strong-field gravity with tidal Love numbers

    Vitor Cardoso🇵🇹 · Edgardo Franzin🇮🇹 · Andrea Maselli🇩🇪 · Paolo Pani🇮🇹 · Guilherme Raposo🇵🇹

    The tidal Love numbers (TLNs) encode the deformability of a self-gravitating object immersed in a tidal environment and depend significantly both on the object's internal structure and on the dynamics of the gravitational field. An intriguing result in classical general relativity is the vanishing of the TLNs of black holes. We extend this result in three ways, aiming at testing the nature of compact objects: (i) we compute the TLNs of exotic compact objects, including different families of boson stars, gravastars, wormholes, and other toy models for quantum corrections at the horizon scale. In the black-hole limit, we find a universal logarithmic dependence of the TLNs on the location of the surface; (ii) we compute the TLNs of black holes beyond vacuum general relativity, including Einstein-Maxwell, Brans-Dicke and Chern-Simons gravity; (iii) We assess the ability of present and future gravitational-wave detectors to measure the TLNs of these objects, including the first analysis of TLNs with LISA. Both LIGO, ET and LISA can impose interesting constraints on boson stars, while LISA is able to probe even extremely compact objects. We argue that the TLNs provide a smoking gun of new physics at the horizon scale, and that future gravitational-wave measurements of the TLNs in a binary inspiral provide a novel way to test black holes and general relativity in the strong-field regime.

    ↳ gr-qcastro-ph.HEhep-phhep-thPRD(2017)·427 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.