Thu·Sep 10, 2015Thursday·September 10, 2015

1. 01*

   Leptonic Dirac CP Violation Predictions from Residual Discrete Symmetries

   I. Girardi🇮🇹 · S. T. Petcov🇮🇹 · Alexander J. Stuart🇮🇹 · A. V. Titov🇮🇹

   Assuming that the observed pattern of 3-neutrino mixing is related to the existence of a (lepton) flavour symmetry, corresponding to a non-Abelian discrete symmetry group $G_f$, and that $G_f$ is broken to specific residual symmetries $G_e$ and $G_{\nu }$ of the charged lepton and neutrino mass terms, we derive sum rules for the cosine of the Dirac phase $\delta$ of the neutrino mixing matrix $U$. The residual symmetries considered are: i) $G_e=Z_2$ and $G_{\nu }=Z_n$, $n>2$ or $Z_n\times Z_m$, $n,m\ge 2$; ii) $G_e=Z_n$, $n>2$ or $Z_n\times Z_m$, $n,m\ge 2$ and $G_{\nu }=Z_2$; iii) $G_e=Z_2$ and $G_{\nu }=Z_2$; iv) $G_e$ is fully broken and $G_{\nu }=Z_n$, $n>2$ or $Z_n\times Z_m$, $n,m\ge 2$; and v) $G_e=Z_n$, $n>2$ or $Z_n\times Z_m$, $n,m\ge 2$ and $G_{\nu }$ is fully broken. For given $G_e$ and $G_{\nu }$, the sum rules for $\cos \delta$ thus derived are exact, within the approach employed, and are valid, in particular, for any $G_f$ containing $G_e$ and $G_{\nu }$ as subgroups. We identify the cases when the value of $\cos \delta$ cannot be determined, or cannot be uniquely determined, without making additional assumptions on unconstrained parameters. In a large class of cases considered the value of $\cos \delta$ can be unambiguously predicted once the flavour symmetry $G_f$ is fixed. We present predictions for $\cos \delta$ in these cases for the flavour symmetry groups $G_f=S_4$, $A_4$, $T^{\prime }$ and $A_5$, requiring that the measured values of the 3-neutrino mixing parameters ${\sin }^2{\theta }_{12}$, ${\sin }^2{\theta }_{13}$ and ${\sin }^2{\theta }_{23}$, taking into account their respective $3\sigma$ uncertainties, are successfully reproduced.

   hep-phNPB(2016)·72 citations
2. 02*

   N${}^3$LO calculations for top-quark differential cross sections near partonic threshold

   Nikolaos Kidonakis🇺🇸

   I present calculations of approximate corrections from NNLL soft-gluon resummation for total and differential cross sections in top-antitop pair production and single-top production in hadronic collisions. I show that soft-gluon corrections from partonic threshold are the dominant contribution to top-quark production and closely approximate exact results. I present aN${}^3$LO results for the total $t\bar{t}$ cross section, the top-quark $p_T$ and rapidity distributions, and the top-quark forward-backward asymmetry. I also provide updates for single-top production in the $t$, $s$, and $tW$ channels. Finally, I discuss top-quark production via anomalous gluon couplings.

   hep-phPoS(2015)·3 citations
3. 03*

   Light Stops and Observation of Supersymmetry at LHC RUN-II

   Bryan Kaufman🇺🇸 · Pran Nath🇺🇸 · Brent D Nelson🇺🇸 · Andrew Spisak🇺🇸

   Light stops consistent with the Higgs boson mass of $\sim 126\mathrm{GeV}$ are investigated within the framework of minimal supergravity. It is shown that models with light stops which are also consistent with the thermal relic density constraints require stop coannihilation with the neutralino LSP. The analysis shows that the residual set of parameter points with light stops satisfying both the Higgs mass and the relic density constraints lie within a series of thin strips in the $m_0-m_{1/2}$ plane for different values of $A_0/m_0$. Consequently, this region of minimal supergravity parameter space makes a number of very precise predictions. It is found that light stops of mass down to 400~GeV or lower can exist consistent with all constraints. A signal analysis for this class of models at LHC RUN-II is carried out and the dominant signals for their detection identified. Also computed is the minimum integrated luminosity for $5\sigma$ discovery of the models analyzed. If supersymmetry is realized in this manner, the stop masses can be as low as 400~GeV or lower, and the mass gap between the lightest neutralino and lightest stop will be approximately 30-40~GeV. We have optimized the ATLAS signal regions specifically for stop searches in the parameter space and find that a stop with mass $\sim 375\mathrm{GeV}$ can be discovered with as little as $\sim$ 60~fb${}^{-1}$ of integrated luminosity at RUN-II of the LHC; the integrated luminosity needed for discovery could be further reduced with more efficient signature analyses. The direct detection of dark matter in this class of models is also discussed. It is found that dark matter cross sections lie close to, but above, coherent neutrino scattering and would require multi-ton detectors such as LZ to see a signal of dark matter for this class of models.

   hep-phhep-exPRD(2015)·27 citations
4. 04*

   Impact of Warped Extra Dimensions on the Dipole Coefficients in $\mathbf{b}\to \mathbf{s\gamma }$ Transitions

   Raoul Malm🇩🇪 · Matthias Neubert🇩🇪 · Christoph Schmell🇩🇪

   We calculate the electro- and chromomagnetic dipole coefficients $C_{7\gamma ,8g}$ and ${\tilde{C}}_{7\gamma ,8g}$ in the context of the minimal Randall-Sundrum (RS) model with a Higgs sector localized on the IR brane using the five-dimensional (5D) approach, where the coefficients are expressed in terms of integrals over 5D propagators. Since we keep the full dependence on the Yukawa matrices, the integral expressions are formally valid to all orders in $v^2/M_{\mathrm{KK}}^2$. In addition we relate our results to the expressions obtained in the Kaluza-Klein (KK) decomposed theory and show the consistency in both pictures analytically and numerically, which presents a non-trivial cross-check. In Feynman-'t Hooft gauge, the dominant corrections from virtual KK modes arise from the scalar parts of the $W^{\pm }$-boson penguin diagrams, including the contributions from the scalar component of the 5D gauge-boson field and from the charged Goldstone bosons in the Higgs sector. The size of the KK corrections depends on the parameter $y_{\ast }$, which sets the upper bound for the anarchic 5D Yukawa matrices. We find that for $y_{\ast }\gtrsim 1$ the dominant KK corrections are proportional to $y_{\ast }^2$. We discuss the phenomenological implications of our results for the branching ratio $\mathrm{Br}(\bar{B}\to X_s\gamma )$, the time-dependent CP asymmetry $S_{K^{\ast }\gamma }$, the direct CP asymmetry $A_{\mathrm{CP}}^{b\to s\gamma }$ and the CP asymmetry difference $\Delta A_{\mathrm{CP}}^{b\to s\gamma }$. We can derive a lower bound on the first KK gluon resonance of $3.8$TeV for $y_{\ast }=3$, requiring that at least $10\%$ of the RS parameter space covers the experimental $2\sigma$ error margins. We further discuss the branching ratio $\mathrm{Br}(\bar{B}\to X_s{l}^{+}{l}^{-})$ and compare our predictions for $C_{7\gamma ,9,10}$ and ${\tilde{C}}_{7\gamma ,9,10}$ with phenomenological results derived from model-independent analyses.

   hep-phJHEP(2016)·17 citations
5. 05*

   ${\Lambda }_c^{+}(2940)$ photoproduction off the neutron

   Xiao-Yun Wang🇨🇳 · Alexey Guskov🇷🇺 · Xu-Rong Chen🇨🇳

   By assuming that the ${\Lambda }_c^{\ast }(2940)$ is a $p{D}^{\ast 0}$ molecular state with spin-parity $J^P={\frac{1}{2}}^{+}$ and $J^P={\frac{1}{2}}^{-}$, the photoproduction of charmed ${\Lambda }_c^{\ast }(2940)$ baryon in the $\gamma n\to D^{-}{\Lambda }_c^{\ast }(2940{)}^{+}$ process is investigated with an effective Lagrangian approach. It is found that the contributions from $t$-channel with $D^{\ast }$ exchange are dominant, while the $s$-channel with nucleon pole exchange give a sizeable contribution around the threshold. The contributions from the $u$-channel and contact term are very small. The total cross section of the $\gamma n\to D^{-}{\Lambda }_c^{\ast }(2940{)}^{+}$ reaction is estimated, which indicate it is feasible to searching for the charmed ${\Lambda }_c^{\ast }(2940)$ baryon at the COMPASS experiment.

   hep-phPRD(2015)·18 citations
6. 06*

   Perturbativity in the seesaw mechanism

   Takehiko Asaka🇯🇵 · Takanao Tsuyuki🇯🇵

   We consider the Standard Model extended by right-handed neutrinos to explain massive neutrinos through the seesaw mechanism. The new fermion can be observed when it has a sufficiently small mass and large mixings to left-handed neutrinos. If such a particle is the lightest right-handed neutrino, its contribution to the mass matrix of active neutrinos needs to be canceled by that of a heavier one. Yukawa couplings of the heavier one are then larger than those of the lightest one. We show that the perturbativity condition gives a severe upper bound on the mixing of the lightest right-handed neutrino, depending on the masses of heavier ones. Models of high energy phenomena, such as leptogenesis, can be constrained by low energy experiments.

   hep-phhep-exPLB(2016)·8 citations
7. 07*

   Anisotropic flow fluctuations in hydro-inspired freeze-out model for relativistic heavy ion collisions

   L.V. Bravina🇳🇴 · E.S. Fotina🇷🇺 · V.L. Korotkikh🇷🇺 · I.P. Lokhtin🇷🇺 · L.V. Malinina🇷🇺 · E.N. Nazarova🇷🇺 · S.V. Petrushanko🇷🇺 · A.M. Snigirev🇷🇺 · E.E. Zabrodin🇳🇴

   The LHC data on event-by-event harmonic flow coefficients measured in PbPb collisions at center-of-mass energy 2.76 TeV per nucleon pair are analyzed and interpreted within the HYDJET++ model. To compare the model results with the experimental data the unfolding procedure is employed. The essentially dynamical origin of the flow fluctuations in hydro-inspired freeze-out approach has been established. It is shown that the simple modification of the model via introducing the distribution over spatial anisotropy parameters permits HYDJET++ to reproduce both elliptic and triangular flow fluctuations and related to it eccentricity fluctuations of the initial state at the LHC energy.

   hep-phnucl-thEPJC(2015)·31 citations
8. 08*

   Hybrid Textures of Neutrino Mass Matrix under the Lamppost of Latest Neutrino and Cosmology Data

   Rupam Kalita🇮🇳 · Debasish Borah🇮🇳

   We study all possible neutrino mass matrices with one zero element and two equal non-zero elements, known as hybrid texture neutrino mass matrices. In the diagonal charged lepton basis, we consider thirty nine such possible cases which are consistent with the latest neutrino data. Using the two constraints on neutrino mass matrix elements imposed by hybrid textures, we numerically evaluate the neutrino parameters like the lightest neutrino mass $m_{\text{lightest}}$, one Dirac CP phase $\delta$ and two Majorana CP phases $\alpha ,\beta$ by using the global fit $3\sigma$ values of three mixing angles and two mass squared differences. We then constrain this parameter space by using the cosmological upper bound on the sum of absolute neutrino masses given by Planck experiment. We also calculate the effective neutrino mass matrix for this region of parameter space which may have relevance in future neutrinoless double beta decay experiments. We finally discriminate between these hybrid texture mass matrices from the requirement of producing correct baryon asymmetry through type I seesaw leptogenesis. We also constrain the light neutrino parameter space as well as the lightest right handed neutrino mass from the constraint on baryon asymmetry of the Universe from Planck experiment.

   hep-phInt.J.Mod.Phys.A(2016)·19 citations
9. 09*

   Pinning down QCD-matter shear viscosity in ultrarelativistic heavy-ion collisions via EbyE fluctuations using pQCD + saturation + hydrodynamics

   K. J. Eskola🇫🇮 · H. Niemi🇩🇪 · R. Paatelainen🇪🇸

   We introduce an event-by-event pQCD + saturation + hydro ("EKRT") framework for high-energy heavy-ion collisions, where we compute the produced fluctuating QCD-matter energy densities from next-to-leading order (NLO) perturbative QCD (pQCD) using saturation to control soft particle production, and describe the space-time evolution of the QCD matter with viscous hydrodynamics, event by event (EbyE). We compare the computed centrality dependence of hadronic multiplicities, p_T spectra and flow coefficients v_n against LHC and RHIC data. We compare also the computed EbyE probability distributions of relative fluctuations of v_n, as well as correlations of 2 and 3 event-plane angles, with LHC data. Our systematic multi-energy and -observable analysis not only tests the initial state calculation and applicability of hydrodynamics, but also makes it possible to constrain the temperature dependence of the shear viscosity-to-entropy ratio, eta/s(T), of QCD matter in its different phases. Remarkably, we can describe all these different flow observables and correlations consistently with eta/s(T) that is independent of the collision energy.

   hep-phnucl-thNucl.Part.Phys.Proc.(2016)·5 citations
10. 10*

    Soft gluon resummation for associated $t\bar{t}H$ production at the LHC

    Anna Kulesza🇩🇪 · Leszek Motyka🇵🇱 · Tomasz Stebel🇵🇱 · Vincent Theeuwes🇩🇪

    We perform resummation of soft gluon corrections to the total cross section for the process $pp\to t\bar{t}H$. The resummation is carried out at next-to-leading-logarithmic (NLL) accuracy using the Mellin space technique, extending its application to the class of $2\to 3$ processes. We present an analytical result for the soft anomalous dimension for a hadronic production of two coloured massive particles in association with a colour singlet. We discuss the impact of resummation on the numerical prediction for the associated Higgs boson production with top quarks at the LHC.

    hep-phJHEP(2016)·73 citations
11. 11*

    Interference Effect on Resonance Studies in Searches of Heavy Particles

    Ligong Bian🇨🇳 · Da Liu🇨🇳 · Jing Shu🇨🇳 · Yongchao Zhang🇨🇳

    The interference between resonance signal and continuum background can be either constructive or destructive, depending on the relative sign of couplings between the signal and background amplitudes. Different interference schemes lead to asymmetric distortions of the resonance line shape, which could be distinguished in experiments, when the internal resonance width is larger than the detector resolution. Interpreting the ATLAS diboson excesses by means of a toy $W^{\prime }$ model as an illustrative example (though it is disfavored by the 13 TeV data), we find that the signs of resonance couplings can only be revealed in the line shape measurements up to a high confidence level at a high luminosity, which could bring us further information on the underlying theory beyond resonance searches at future lepton and hadron colliders.

    hep-phhep-exInt.J.Mod.Phys.(2016)·17 citations
12. 12*

    Nuclear PDF constraints from p+Pb collisions at the LHC

    Ilkka Helenius🇸🇪 · Hannu Paukkunen🇫🇮 · Kari J. Eskola🇫🇮

    As the current nuclear PDF analyses are mainly constrained by fixed-target Drell-Yan and deeply inelastic scattering data only the quark nuclear modifications at fairly large $x$ values are in a good control. Inclusive pion production in d+Au collisions at RHIC provides some constraints for gluons but due to the limited kinematic reach of the data the gluon modifications remain uncertain especially at small values of $x$. In this talk, we discuss how the existing data from p+Pb collisions at the LHC can improve the nuclear PDF fits and which measurements would be sensitive to the small-$x$ gluons. In particular, we consider inclusive hadron production, compare this to direct photons, and show estimates of the effect of CMS dijet measurements to the uncertainty of nuclear gluon distributions.

    hep-phnucl-thPoS(2015)·8 citations
13. 13*

    Electron-Ion Physics with the LHeC

    Ilkka Helenius🇸🇪 · Hannu Paukkunen🇫🇮 · Néstor Armesto🇪🇸

    The Large Hadron Electron Collider (LHeC) project is the proposal to use the existing LHC proton/ion beams and construct a new electron beam line to perform high-energy electron-proton/ion collisions. In this talk, we consider some of the physics topics that could be studied in the electron-ion mode. In particular, we estimate how much the current nuclear parton distribution fits could be improved with the deeply inelastic scattering measurements at the LHeC by including pseudodata into a global analysis. In addition, we discuss briefly other topics that would help to better understand some aspects of heavy-ion collisions, namely small-$x$ physics and hadron production with a nuclear target.

    hep-phPoS(2015)·3 citations
14. 14*

    Scale-dependent CMB power asymmetry from primordial speed of sound and a generalized $\delta$N formalism

    Dong-Gang Wang🇨🇳 · Yi-Fu Cai🇨🇦 · Wen Zhao🇨🇳 · Yang Zhang🇨🇳

    We explore a plausible mechanism that the hemispherical power asymmetry in the CMB is produced by the spatial variation of the primordial sound speed parameter. We suggest that in a generalized approach of the $\delta N$ formalism the local e-folding number may depend on some other primordial parameters besides the initial values of inflaton. Here the $\delta N$ formalism is extended by considering the effects of a spatially varying sound speed parameter caused by a super-Hubble perturbation of a light field. Using this generalized $\delta N$ formalism, we systematically calculate the asymmetric primordial spectrum in the model of multi-speed inflation by taking into account the constraints of primordial non-Gaussianities. We further discuss specific model constraints, and the corresponding asymmetry amplitudes are found to be scale-dependent, which can accommodate current observations of the power asymmetry at different length scales.

    ↳ astro-ph.COgr-qchep-phhep-thJCAP(2016)·11 citations
15. 15*

    Impressions of the Meson Spectrum: Hybrids & Exotics, present and future

    M.R. Pennington🇺🇸

    It has long been expected that the spectrum of hadrons in QCD would be far richer and extensive than experiment has so far revealed. While there have been experimental hints of this richness for some time, it is really only in the last few years that dramatic progress has been seen in the exploration both experimentally and in calculations on the lattice. Precision studies enabled by new technology both with detectors and high performance computations are converging on an understanding of the spectrum in strong coupling QCD. These methodologies are laying the foundation for a decade of potential discovery that electro and photoproduction experiments at Jefferson Lab, which when combined with key results on $B$ and charmonium decays from both $e^{+}{e}^{-}$ and $pp$ colliders, should turn mere impressions of the light meson spectrum into a high definition picture.

    ↳ nucl-thhep-phEPJ Web Conf.(2016)·4 citations
16. 16*

    Remarks on nonlinear electrodynamics II

    Patricio Gaete🇨🇱

    We consider both massive Euler-Heisenberg-like and Euler-Heisenberg-like Electrodynamics in the approximation of the strong-field limit. Our analysis shows that massive Euler-Heisenberg-type Electrodynamics displays the vacuum birefringence phenomenon. Afterwards, we calculate the lowest-order modifications to the interaction energy for both classes of Electrodynamics, within the framework of the gauge-invariant path-dependent variables formalism. Interestingly enough, for massive Euler-Heisenbeg-like electrodynamics (Whichmann-Kroll) we obtain a new long-range ($1/r^3$- type) correction, apart from a long-range ($1/r^5$- type) correction to the Coulomb potential. However, Euler-Heisenberg-like Electrodynamics in the approximation of the strong-field limit (to the leading logarithmic order), display a long-range ($1/r^5$- type) correction to the Coulomb potential. Again, for their non-commutative versions, the interaction energy is ultraviolet finite.

    ↳ hep-thhep-phAdv.High Energy Phys.(2016)·8 citations
17. 17*

    Perspective of monochromatic gamma-ray line detection with the High Energy cosmic-Radiation Detection (HERD) facility onboard China's Space Station

    Xiaoyuan Huang🇩🇪 · Anna S. Lamperstorfer🇩🇪 · Yue-Lin Sming Tsai🇯🇵 · Ming Xu🇨🇳 · Qiang Yuan🇺🇸 · Jin Chang🇨🇳 · Yong-Wei Dong🇨🇳 · Bing-Liang Hu🇨🇳 · Jun-Guang Lü🇨🇳 · Le Wang🇨🇳 · Bo-Bing Wu🇨🇳 · Shuang-Nan Zhang🇨🇳

    HERD is the High Energy cosmic-Radiation Detection instrument proposed to operate onboard China's space station in the 2020s. It is designed to detect energetic cosmic ray nuclei, leptons and photons with a high energy resolution ($\sim 1\%$ for electrons and photons and $20\%$ for nuclei) and a large geometry factor ($>3m^{2}sr$ for electrons and diffuse photons and $>2m^{2}sr$ for nuclei). In this work we discuss the capability of HERD to detect monochromatic $\gamma$-ray lines, based on simulations of the detector performance. It is shown that HERD will be one of the most sensitive instruments for monochromatic $\gamma$-ray searches at energies between $\sim 10$ to a few hundred GeV. Above hundreds of GeV, Cherenkov telescopes will be more sensitive due to their large effective area. As a specific example, we show that a good portion of the parameter space of a supersymmetric dark matter model can be probed with HERD.

    ↳ astro-ph.HEastro-ph.IMhep-phAstropart.Phys.(2016)·39 citations
18. 18*

    Forecasting sensitivity on tilt of power spectrum of primordial gravitational waves after Planck satellite

    Qing-Guo Huang🇨🇳 · Sai Wang🇨🇳 · Wen Zhao🇨🇳

    By taking into account the contamination of foreground radiations, we employ the Fisher matrix to forecast the future sensitivity on the tilt of power spectrum of primordial tensor perturbations for several ground-based (AdvACT, CLASS, Keck/BICEP3, Simons Array, SPT-3G), balloon-borne (EBEX, Spider) and satellite (CMBPol, COrE, LiteBIRD) experiments of B-mode polarizations. For the fiducial model $n_t=0$, our results show that the satellite experiments give good sensitivity on the tensor tilt $n_t$ to the level ${\sigma }_{n_t}\lesssim 0.1$ for $r\gtrsim 2\times 10^{-3}$, while the ground-based and balloon-borne experiments give worse sensitivity. By considering the BICEP2/Keck Array and Planck (BKP) constraint on the tensor-to-scalar ratio $r$, we see that it is impossible for these experiments to test the consistency relation $n_t=-r/8$ in the canonical single-field slow-roll inflation models.

    ↳ astro-ph.COgr-qchep-phhep-thJCAP(2015)·40 citations
19. 19*

    Phase Diagram of Dynamical Twisted Mass Wilson Fermions at Finite Isospin Chemical Potential

    Oliver Janssen🇺🇸 · Mario Kieburg🇩🇪 · K. Splittorff🇩🇰 · Jacobus J. M. Verbaarschot🇺🇸 · Savvas Zafeiropoulos🇩🇪

    We consider the phase diagram of twisted mass Wilson fermions of two-flavor QCD in the parameter space of the quark mass, the isospin chemical potential, the twist angle and the lattice spacing. This work extends earlier studies in the continuum and those at zero chemical potential. We evaluate the phase diagram as well as the spectrum of the (pseudo-)Goldstone bosons using the chiral Lagrangian for twisted mass Wilson fermions at non-zero isospin chemical potential. The phases are obtained from a mean field analysis. At zero twist angle we find that already an infinitesimal isospin chemical potential destroys the Aoki phase. The reason is that in this phase we have massless Goldstone bosons with a non-zero isospin charge. At finite twist angle only two different phases are present, one phase which is continuously connected to the Bose condensed phase at non-zero chemical potential and another phase which is continuously connected to the normal phase. For either zero or maximal twist the phase diagram is more complicated as the saddle point equations allow for more solutions.

    ↳ hep-lathep-phhep-thPRD(2016)·27 citations
20. 20*

    Model-Independent Measurement of the e+e- -> HZ Cross Section at a Future e+e- Linear Collider using Hadronic Z Decays

    Mark Thomson🇬🇧

    A future e+e- collider, such as the ILC or CLIC, would allow the Higgs sector to be probed with a precision significantly beyond that achievable at the High-Luminosity LHC. A central part of the Higgs programme at an e+e- collider is the model-independent determination of the absolute Higgs couplings to fermions and to gauge bosons. Here the measurement of the e+e-->HZ Higgsstrahlung cross section, using the recoil mass technique, sets the absolute scale for all Higgs coupling measurements. Previous studies have considered e+e- ->ZH with Z->l+l-, where l = electron or muon. In this paper it is shown for the first time that a near model-independent recoil mass technique can be extended to the hadronic decays of the Z boson. Because the branching ratio for Z->qq is approximately ten times greater than for Z->l+l-, this method is statistically more powerful than using the leptonic decays. For an integrated luminosity of 500 fb-1 at a centre-of-mass energy of 350 GeV at CLIC, the e+e-->HZ cross section can be measured to 1.8 % using the hadronic recoil mass technique. A similar precision is found for the ILC operating at 350 GeV. The centre-of-mass dependence of this measurement technique is discussed, arguing for the initial operation of a future linear collider at just above the top-pair production threshold.

    ↳ hep-exhep-phEPJC(2016)·59 citations
21. 21*

    Vector potentials in gauge theories in flat spacetime

    C. W. Wong🇺🇸

    A recent suggestion that vector potentials in electrodynamics (ED) are nontensorial objects under 4D frame rotations is found to be both unnecessary and confusing. As traditionally used in ED, a vector potential $A$ always transforms homogeneously under 4D rotations in spacetime, but if the gauge is changed by the rotation, one can restore the gauge back to the original gauge by adding an inhomogeneous term. It is then "not a 4-vector", but two: one for rotation and one for translation. For such a gauge, it is much more important to preserve {\it explicit} homogeneous Lorentz covariance by simply skipping the troublesome gauge-restoration step. A gauge-independent separation of $A$ into a dynamical term and a non-dynamical term in Abelian gauge theories is re-defined more generally as the terms caused by the presence and absence respectively of the 4-current term in the inhomogeneous Maxwell equations for $A$. Such a separation {\it cannot} in general be extended to non-Abelian theories where $A$ satisfies nonlinear differential equations. However, in the linearized iterative solution that is perturbation theory, the usual Abelian quantizations in the usual gauges can be used. Some nonlinear complications are briefly reviewed.

    ↳ physics.gen-phhep-phPRD(2015)·0 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.