Tue·Jan 3, 2017Tuesday·January 3, 2017

1. 01*

   Fine-tuning the Color-Glass Condensate with the nuclear configurational entropy

   Gayane Karapetyan🇧🇷

   The dipole-nucleus forward scattering amplitude rules the onset of the gluon anomalous dimension, in the Color-Glass Condensate regime. In this model, the onset of quantum regime is here derived as a critical stable point in the nuclear configurational entropy, matching the fitted experimental data in the literature with accuracy of 1%. It corroborates with the informational entropy paradigm in high energy nuclear physics.

   hep-phhep-thnucl-thEPL(2017)·38 citations
2. 02*

   Displaced Photon Signal from a Light Scalar in Minimal Left-Right Symmetric Model

   P. S. Bhupal Dev🇺🇸 · Rabindra N. Mohapatra🇺🇸 · Yongchao Zhang🇧🇪

   We point out that in the minimal left-right realization of TeV scale seesaw for neutrino masses, the neutral scalar from the right-handed $SU(2{)}_R$ breaking sector could be much lighter than the right-handed scale. We discuss for the first time the constraints on this particle from low-energy flavor observables, find that the light scalar is necessarily long-lived. We show that it can be searched for at the LHC via displaced signals of a collimated photon jet, and can also be tested in current and future high-intensity experiments. In contrast to the unique diphoton signal (and associated jets) in the left-right case, a generic beyond Standard Model light scalar decays mostly to leptons or jets. Thus, the diphoton channel proposed here provides a new avenue to test the left-right framework and reveal the underlying neutrino mass generation mechanism.

   hep-phhep-exPRD(2017)·58 citations
3. 03*

   The shear viscosity of two-flavor crystalline color superconducting quark matter

   Sreemoyee Sarkar🇮🇳 · Rishi Sharma🇮🇳

   We present the first calculation of the shear viscosity for two-flavor plane wave (FF) color superconducting quark matter. This is a member of the family of crystalline color superconducting phases of dense quark matter that may be present in the cores of neutron stars. The paired quarks in the FF phase feature gapless excitations on surfaces of crescent shaped blocking regions in momentum space and participate in transport. We calculate their contribution to the shear viscosity. We note that they also lead to dynamic screening of transverse $t^1$, $t^2$, $t^3$ gluons which are undamped in the 2SC phase. The exchange of these gluons is the most important mechanism of the scattering of the paired quarks. We find that the shear viscosity of the paired quarks is roughly a factor of $100$ smaller compared to the shear viscosity of unpaired quark matter. Our results may have implications for the damping of $r-$modes in rapidly rotating, cold neutron stars.

   hep-phnucl-thPRD(2017)·16 citations
4. 04*

   Quenching preheating by light fields

   Olga Czerwińska🇵🇱 · Seishi Enomoto🇺🇸 · Zygmunt Lalak🇵🇱

   In this paper we investigate the role of additional light fields not directly coupled to the background during preheating. We extend our previous study that proved that the production of particles associated with such fields can be abundant due to quantum corrections, even for the massless states. We also obtain the expression for the occupation number operator in terms of interacting fields which includes the non-linear effects important for non-perturbative particle production. We show that adding too many light degrees of freedom without direct interactions with the background might attenuate or even quench preheating as the result of backreaction effects.

   hep-phPRD(2017)·3 citations
5. 05*

   Black Holes, Dark Matter Spikes, and Constraints on Simplified Models with $t$-Channel Mediators

   Pearl Sandick🇺🇸 · Kuver Sinha🇺🇸 · Takahiro Yamamoto🇺🇸

   The density spike of dark matter (DM) in the subparsec region near the supermassive black hole at the Galactic Center can provide potentially observable gamma-ray signals coming from DM annihilations. Taking Fermi-$LAT$ data for the gamma-ray flux from the point source 3FGL J1745.6-2859c (Sgr A*), we calculate the resulting constraints on generic models of DM, allowing for the possibility of a non-negligible velocity-dependent component of the annihilation cross section. We consider a variety of selections for the astrophysical parameters that describe the spike profile and find that the gamma-ray flux is strongly dependent on these selections, particularly the modelling of spike depletion effects due to gravitational interactions with baryons, which affect the spike radius and steepness profile. We calculate constraints on the DM parameter space for both attenuated and idealized spikes, considering different choices for the steepness profiles in each case. We find that for the most conservative selection of parameters, corresponding to a depleted spike with an NFW cusp profile, the gamma-ray flux for a 100 GeV thermal relic is lower than current observational constraints by several orders of magnitude. For more optimistic choices of parameters corresponding to spikes that have not been attenuated, bounds on DM masses can be obtained for a variety of choices of steepness profiles. We then specialize to a class of simplified models of fermionic DM that annihilate dominantly through the $t-$channel exchange of two scalar mediators with arbitrary mixing angle $\alpha$, and calculate the indirect detection constraints coming from the DM spike. Along the way, we discuss constraints on the astrophysical parameters describing the DM spike, taking the Galactic Center excess as a signal of DM annihilation.

   hep-phastro-ph.COastro-ph.HEPRD(2018)·23 citations
6. 06*

   Efectos de Temperatura Finita y Curvatura en QCD y Modelos de Quarks Quirales

   Eugenio Megias🇪🇸

   We develop the heat kernel method in the context of finite temperature quantum field theory. We compute the heat kernel expansion in the presence of general gauge and scalar fields which may be non Abelian and non stationary. The Polyakov loop appears at finite temperature as a new gauge covariant operator. We apply this method in the computation of the fully gauge invariant effective action of QCD in the regime of high temperature. It is obtained the dimensionally reduced effective action of QCD as well. In the context of chiral quark models, in particular the Nambu--Jona-Lasinio and the spectral quark model, we apply this method to compute the low-energy chiral Lagrangian at finite temperature. The coupling of the Polyakov loop with these models allows to solve some inconsistencies appearing in the standard treatment at finite temperature: generation of multi-quark states, large $N_c$ counting, etc. On the other hand, we show that recent available lattice data for the renormalized Polyakov loop above the deconfinement phase transition exhibit unequivocal inverse power temperature corrections driven by a dimension 2 gluon condensate. This simple ansatz provides a good overall description of the data throughout the deconfinement phase until near the critical temperature with just two parameters. Finally, we study several chiral quark models in the light of chiral perturbation theory in curved space-time. The low energy structure of the energy momentum tensor in these models with SU(3) flavor symmetry is analyzed in the presence of external gravitational fields.

   hep-phhep-lathep-thnucl-thEditorial of the University of Granada. I…·0 citations
7. 07*

   Legendre Analysis of Differential Distributions in Hadronic Reactions

   Yakov I. Azimov (PNPI)🇷🇺 · Igor I. Strakovsky (GWU)🇺🇸 · William J. Briscoe (GWU)🇺🇸 · Ron L. Workman (GWU)🇺🇸

   Modern experimental facilities, such as CBELSA, ELPH, JLab, MAMI and SPring-8 have provided a tremendous volume of data, often with wide energy and angular coverage, and with increasing precision. For reactions with two hadrons in the final state, these data are often presented as multiple sets of panels, with angular distributions at numerous specific energies. Such presentations have limited visual appeal, and their physical content is typically extracted through some model- dependent treatment. Instead, we explore the use of a Legendre series expansion with a relatively small number of essential coefficients. This approach has been applied in several recent experimental investigations. We present some general properties of the Legendre coefficients in the helicity framework and consider what physical information can be extracted without any model-dependent assumptions.

   hep-phhep-exnucl-exnucl-thPRC(2017)·4 citations
8. 08*

   On the possibility of search for $L_{\mu }-L_{\tau }$ gauge boson at Belle-II and neutrino beam experiments

   Yuya Kaneta🇯🇵 · Takashi Shimomura🇯🇵

   We study the possibilities on the search of the light and weakly interacting gauge boson in the gauged $L_{\mu }-L_{\tau }$ model. Introducing the kinetic mixing at the tree-level, the allowed parameter regions for the gauge coupling and kinetic mixing parameter are presented. Then, we analyze one photon plus missing event within the allowed region and show that search for the light gauge boson will be possible at Belle-II experiment. We also analyze neutrino trident production process in neutrino beam experiments.

   hep-phhep-exPTEP(2017)·81 citations
9. 09*

   Analytical Forms for Cross Sections of Di-lepton Production from $e^{+}{e}^{-}$ Collisions around the $J/\psi$ Resonance

   Xing-Yu Zhou🇨🇳 · Ya-Di Wang🇩🇪 · Li-Gang Xia🇨🇳

   A detailed theoretical derivation of the cross sections of $e^{+}{e}^{-}\to e^{+}{e}^{-}$ and $e^{+}{e}^{-}\to {\mu }^{+}{\mu }^{-}$ around the $J/\psi$ resonance is reported. The resonance and interference parts of the cross sections, related to $J/\psi$ resonance parameters, are calculated. Higher-order corrections for vacuum polarization and initial-state radiation are considered. An arbitrary upper limit of radiative correction integration is involved. Full and simplified versions of analytic formulae are given with precision at the level of 0.1% and 0.2%, respectively. Moreover, the results obtained in the paper can be applied to the case of the $\psi (3686)$ resonance.

   hep-phhep-exCPC(2017)·5 citations
10. 10*

    Central-edge asymmetry as a probe of Higgs-top coupling in $t\bar{t}h$ production at LHC

    Jinmian Li🇰🇷 · Zong-guo Si🇨🇳 · Lei Wu🇨🇳 · Jason Yue🇹🇼

    The Higgs-top coupling plays a central role in the hierarchy problem and the vacuum stability of the Standard Model (SM). We propose a central-edge asymmetry ($A_{CE}$) to probe the CP violating Higgs-top coupling in dileptonic channel of $t\bar{t}h(\to b\bar{b})$ production at the LHC. We demonstrate that the CP-violating Higgs-top coupling can affect the central-edge asymmetry through distorting $\Delta y_{{\ell }^{+}{\ell }^{-}}$ distribution because of the contribution of new top charge asymmetric term. Since $\Delta y_{{\ell }^{+}{\ell }^{-}}$ distribution is frame-independent and has a good discrimination even in boosted regime, we use the jet substructure technique to enhance the observability of the dileptonic channel of $t\bar{t}h$ production. We find that (1) the significance of dileptonic channel of $t\bar{t}h$ production can reach $5\sigma$ for CP phase $\xi =0,\pi /4,\pi /2$ when the luminosity $\mathcal{L}=795,993,1276$ fb${}^{-1}$ at 14 TeV LHC. (2) the central-edge asymmetry $A_{CE}$ show a good discrimination power of CP phase of $t\bar{t}h$ interaction, which are -40.26\%, -26.60\%, -9.47\% for $\xi =0$, $\pi /4$, $\pi /2$ respectively and are hardly affected by the event selections. Besides, by performing the binned-${\chi }^2$ analysis of $\Delta y_{{\ell }^{+}{\ell }^{-}}$ distribution, we find that the scalar and pseudo-scalar interactions can be distinguished at 95\% C.L. level at 14 TeV HL-LHC.

    hep-phhep-exPLB(2018)·23 citations
11. 11*

    From condensed matter to QCD: a journey through gauge theories on board of a variational tool

    Fabio Siringo🇮🇹

    Starting with a review of the thermal fluctuations in superconductors, the Gaussian Effective Potential is shown to be a powerful variational tool for the study of the breaking of symmetry in gauge theories. A novel re-derivation of the massive expansion for QCD is presented, showing its variational nature and its origin from the Gaussian potential that also provides a variational proof for chiral symmetry breaking and dynamical generation of a gluon mass.

    hep-ph4 citations
12. 12*

    The Mar(e)k of QGP: Strangeness

    Jan Rafelski🇺🇸

    Strangeness signature of of quark-gluon plasma (QGP) is central to the exploration of baryon-dense matter: the search for the critical point and onset of deconfinement. I report on the discovery of QGP by means of strangeness: The key historical figures and their roles in this quest are introduced and the experimental results obtained are discussed. The important role of antihyperons is emphasized. The statistical hadronization model, and sudden hadronization are described. Results of present day data analysis: strangeness and entropy content of a large fireball, and the universal hadronization condition describing key features of all explored collision systems are presented.

    hep-phnucl-thphysics.hist-phActa Phys.Polon.Supp.B(2017)·1 citation
13. 13*

    Impact of lepton flavour universality violation on CP violation sensitivity of long baseline neutrino oscillation experiments

    Soumya C.🇮🇳 · R. Mohanta🇮🇳

    The observation of neutrino oscillation as well as the recent experimental result on lepton flavor universality (LFU) violation in $B$ meson decays are indications of new physics beyond the Standard Model. Many theoretical models, which are introduced in the literature as an extension of SM to explain these observed deviations in LFU, lead to new kind of interactions so-called non-standard interaction (NSI) between the elementary particles. In this paper, we consider a model with an additional $Z^{\prime }$ boson (which is quite successful in explaining the observed LFU anomalies) and analyze its effect in the lepton flavour violating (LFV) $B_d\to {\tau }^{\pm }{e}^{\mp }$ decay modes. From the present upper bound of the $B_d\to {\tau }^{\pm }{e}^{\mp }$ branching ratio, we obtain the constraints on the new physics parameters, which are related to the corresponding NSI parameters in the neutrino sector by $SU(2{)}_L$ symmetry. These new parameters are expected to have potential implications in the neutrino oscillation studies and in this work we investigate the possibility of observing the effects of these interactions in the currently running and upcoming long-baseline experiments, i.e., NOvA and DUNE respectively.

    hep-phEPJC(2017)·6 citations
14. 14*

    Accessing unpolarized and linearly polarized gluon TMDs through quarkonium production

    Asmita Mukherjee🇮🇳 · Sangem Rajesh🇮🇳

    We present the study of accessing unpolarized and linearly polarized gluon TMDs in J/{\psi} and {\Upsilon}(1S) production in unpolarized proton-proton collision at LHC, RHIC and AFTER energies. Non- relativistic QCD based color octet model (COM) is used for estimating quarkonium production rates within transverse momentum dependent factorization formalism. A comparison is drawn between the experimental data and the transverse momentum distribution of quarkonium obtained in COM and color evaporation model.

    hep-ph0 citations
15. 15*

    Quark Wigner Distributions Using Light-Front Wave Functions

    Jai More🇮🇳 · Asmita Mukherjee🇮🇳 · Sreeraj Nair🇮🇳

    The quasi-probabilistic Wigner distributions are the quantum mechanical analog of the classical phase-space distributions. We investigate quark Wigner distributions for a quark state dressed with a gluon, which can be thought of as a simple composite and relativistic spin-1/2 state with a gluonic degree of freedom. We calculate various polarization configurations, namely unpolarized, longitudinally polarized and transversely polarized quark and the target state using light-front wave functions in this model. At leading twist, one can define 16 quark Wigner distributions, however, we obtain only 8 independent non-zero Wigner distributions in our model. We compare our results with other model calculations for the proton.

    hep-phPRD(2017)·42 citations
16. 16*

    A discussion on leading renormalon in the pole mass

    Javad Komijani🇩🇪

    Perturbative series of some quantities in quantum field theories, such as the pole mass of a quark, suffer from a kind of divergence called renormalon divergence. In this paper, the leading renormalon in the pole mass is investigated, and a map is introduced to suppress this renormalon. The inverse of the map is then used to generate the leading renormalon and obtain an expression to calculate its overall normalization. Finally, the overall normalization of the leading renormalon of the pole mass is calculated for several values of quark flavors.

    hep-phmath-phmath.MPJHEP(2017)·30 citations
17. 17*

    Production of forward di-jet in p+Pb collisions in the small-$x$ improved TMD factorization framework

    Krzysztof Kutak🇵🇱

    We report on recent study of the production of forward di-jets in proton-proton and proton-lead collisions at the Large Hadron Collider with Improved Transversal Momentum Factorization \cite{vanHameren:2016ftb}. The results as compared to results obtained within High Energy Factorization show noticable effects related to detailed treatment of nonlinear effects.

    hep-phPoS(2016)·0 citations
18. 18*

    Production of four-jets in single- and double-parton scattering within high-energy factorization

    Krzysztof Kutak🇵🇱

    We report on a first study of 4-jet production in a high energy factorization (HEF) framework \cite{Kutak:2016mik,Kutak:2016ukc}. We include and discuss contributions from both single-parton scattering (SPS) and double-parton scattering (DPS) and compare to the measured data. The DPS HEF result is considerably smaller than the one obtained with collinear factorization. The mechanism leading to this difference is of kinematical nature. In contrast to the collinear approach, the HEF approach nicely describes the distribution of the $\Delta S$ variable, which involves all four jets and their angular correlations.

    hep-phPoS(2016)·2 citations
19. 19*

    Identifying the QCD Phase Transitions via the Gravitational Wave Frequency

    Wei-jie Fu🇨🇳 · Zhan Bai🇨🇳 · Yu-xin Liu🇨🇳

    We investigate the nonradial oscillations of newly born neutron stars (NSs) and strange quark stars (SQSs). This is done with the relativistic nuclear field theory with hyperon degrees of freedom employed to describe the equation of state for the stellar matter in NSs, and with both the MIT bag model and the Nambu--Jona-Lasinio model adopted to construct the configurations of the SQSs. We find that the gravitational-mode ($g$-mode) eigenfrequencies of newly born SQSs are about one order of magnitude lower than those of NSs, which is independent of models implemented to describe the equation of state for the strange quark matter. Meanwhile the eigenfrequencies of the other modes of nonradial oscillations, e.g., fundamental ($f$)- and pressure ($p$)-modes, are much larger than those of the $g$-mode. In the light of the first direct observation of gravitational waves, it is promising to employ the gravitational waves to identify the QCD phase transition in high density strong interaction matter.

    hep-phastro-ph.HEnucl-th5 citations
20. 20*

    The Mont Blanc neutrinos from SN 1987A: Could they have been monochromatic (8 MeV) tachyons with $m^2=-0.38$ keV${}^2$?

    Robert Ehrlich🇺🇸

    Here we consider faster-than-light neutrinos having $m_{\nu }^2=-0.38$ $ke{V}^2$ as the explanation of the Mont Blanc burst. It is shown that the Mont Blanc burst is consistent with the distinctive signature of that explanation i.e., an 8 MeV antineutrino line from SN 1987A. It is further shown that a model of core collapse supernovae involving dark matter particles of mass 8 MeV would in fact yield an 8 MeV antineutrino line. Moreover, that dark matter model predicts 8 MeV $\nu ,\bar{\nu }$ and $e^{+}{e}^{-}$ pairs from the galactic center, a place where one would expect large amounts of dark matter to collect. The resulting $e^{+}$ would create $\gamma -$rays from the galactic center, and a fit to MeV $\gamma -$ray data yields the model's dark matter mass, as well as the calculated source temperature and angular size. More direct support comes from the spectrum of $N\sim 1000$ events recorded by the Kamiokande-II detector on the day of SN 1987A, which appear to show an 8 MeV line atop the detector background. This $\bar{\nu }$ line, if genuine, has been well-hidden for 30 years because it occurs very close to the peak of the background. This fact might ordinarily justify extreme skepticism. In the present case, however, a more positive view is called for based on (a) the very high statistical significance of the result $(30\sigma ),$ (b) the use of a detector background independent of the SN 1987A data using a later K-II data set, and (c) the observation of an excess above the background spectrum whose central energy and width both agree with that of an 8 MeV $\bar{\nu }$ line broadened by $25\%$ resolution. Lastly, it is noted that the tachyonic interpretation of the Mont Blanc burst fits the author's earlier unconventional $3+3$ model of the neutrino mass states.

    hep-phAstropart.Phys.(2018)·9 citations
21. 21*

    A neutrino mass-mixing sum rule from SO(10) and neutrinoless double beta decay

    F. Buccella🇮🇹 · M. Chianese🇮🇹 · G. Mangano🇮🇹 · G. Miele🇮🇹 · S. Morisi🇮🇹 · P. Santorelli🇮🇹

    Minimal SO(10) grand unified models provide phenomenological predictions for neutrino mass patterns and mixing. These are the outcome of the interplay of several features, namely: i) the seesaw mechanism; ii) the presence of an intermediate scale where B-L gauge symmetry is broken and the right-handed neutrinos acquire a Majorana mass; iii) a symmetric Dirac neutrino mass matrix whose pattern is close to the up-type quark one. In this framework two natural characteristics emerge. Normal neutrino mass hierarchy is the only allowed, and there is an approximate relation involving both light-neutrino masses and mixing parameters. This differs from what occurring when horizontal flavour symmetries are invoked. In this case, in fact, neutrino mixing or mass relations have been separately obtained in literature. In this paper we discuss an example of such comprehensive mixing-mass relation in a specific realization of SO(10) and, in particular, analyse its impact on the expected neutrinoless double beta decay effective mass parameter $⟨m_{ee}⟩$, and on the neutrino mass scale. Remarkably a lower limit for the lightest neutrino mass is obtained ($m_{\mathrm{lightest}}\gtrsim 7.5\times 10^{-4}$ eV, at 3 $\sigma$ level).

    hep-phJHEP(2017)·15 citations
22. 22*

    DPS in CGC: HBT correlations in double inclusive photon production

    Alex Kovner🇺🇸 · Amir H. Rezaeian🇨🇱

    We introduce a technique to study double parton scattering (DPS) in the Color-Glass-Condensate (CGC) approach. We show that the cross-section of the DPS in the CGC approach is calculable in terms of new nonperturbative objects, generalized double transverse momentum-dependent parton distribution (2GTMD) functions. We investigate the production of pairs of prompt photons from two partons in the projectile hadron in high-energy proton-nucleus collisions. We show that even for independent partons in the projectile, the prompt photon correlation function exhibits Hanbury Brown and Twiss (HBT) correlations. The width of the HBT peak is controlled by the transverse distance between the parton of the pair, which is of the order of the proton size. Thus, the HBT measurements in two-particle production such as prompt photon pairs provide useful information about the nonperturbative 2GTMDs.

    hep-phhep-exnucl-thPRD(2017)·12 citations
23. 23*

    Liquid-Gas Phase Transitions and $\mathcal{C}\mathcal{K}$ Symmetry in Quantum Field Theories

    Hiromichi Nishimura🇺🇸 · Michael C. Ogilvie🇺🇸 · Kamal Pangeni🇺🇸

    A general field-theoretic framework for the treatment of liquid-gas phase transitions is developed. Starting from a fundamental four-dimensional field theory at nonzero temperature and density, an effective three-dimensional field theory with a sign problem is derived. Although charge conjugation $\mathcal{C}$ is broken at finite density, there remains a symmetry under $\mathcal{C}\mathcal{K}$, where $\mathcal{K}$ is complex conjugation. We consider four models: relativistic fermions, nonrelativistic fermions, static fermions and classical particles. The thermodynamic behavior is extracted from $\mathcal{C}\mathcal{K}$-symmetric complex saddle points of the effective field theory at tree level. The relativistic and static fermions show a liquid-gas transition, manifesting as a first-order line at low temperature and high density, terminated by a critical end point. In the cases of nonrelativistic fermions and classical particles, we find no first-order liquid-gas transitions at tree level. The mass matrix controlling the behavior of correlation functions is obtained from fluctuations around the saddle points. Due to the $\mathcal{C}\mathcal{K}$ symmetry of the models, the eigenvalues of the mass matrix can be complex. This leads to the existence of disorder lines, which mark the boundaries where the eigenvalues go from purely real to complex. The regions where the mass matrix eigenvalues are complex are associated with the critical line. In the case of static fermions, a powerful duality between particles and holes allows for the analytic determination of both the critical line and the disorder lines. Depending on the values of the parameters, either zero, one or two disorder lines are found. Numerical results for relativistic fermions give a very similar picture.

    ↳ hep-thhep-lathep-phnucl-thPRD(2017)·9 citations
24. 24*

    Perspective on MOND emergence from Verlinde's "emergent gravity" and its recent test by weak lensing

    Mordehai Milgrom (Weizmann Institute)🇮🇱 · Robert H. Sanders (Kapteyn Institute)🇳🇱

    We highlight phenomenological aspects of Verlinde's recent proposal to account for the mass anomalies in galactic systems without dark matter -- in particular in their relation to MOND. Welcome addition to the MOND lore as it is, this approach have reproduced, so far, only a small fraction of MOND phenomenology, and is still rather tentative, both in its theoretical foundations and in its phenomenology. What Verlinde has extracted from this approach, so far, is a formula -- of rather limited applicability, and with no road to generalization in sight -- for the effective gravitational field of a spherical, isolated, static baryonic system. This formula cannot be used to calculate the gravitational field of disk galaxies, with their rich MOND phenomenology. Notably, it cannot predict their rotation curves, except asymptotically. It does not apply to the few-, or many-body problem; so, it cannot give, e.g., the two-body force between two galaxies, or be used to conduct N-body calculations of galaxy formation, evolution, and interactions. The formula cannot be applied to the internal dynamics of a system embedded in an external field, where MOND predicts important consequences. etc. MOND is backed by full-fledged, Lagrangian theories that can be, and are, routinely applied to all the above phenomena, and more. Verlinde's formula, as it now stands, strongly conflicts with solar-system and possibly earth-surface constraints, and cannot fully account for the mass anomalies in the cores of galaxy clusters (a standing conundrum in MOND). The recent weak-lensing test of the formula is, in fact, testing a cornerstone prediction of MOND, one that the formula does reproduce, and which has been tested before in the very same way.

    ↳ astro-ph.GAastro-ph.COgr-qchep-ph+126 citations
25. 25*

    Anomalous transport and massive gravity theories

    Eugenio Megias🇪🇸

    We review the Kubo formulae relevant to study anomalous transport properties of relativistic fluids. We apply this formalism to perform a computation of the transport coefficients in a holographic massive gravity model including vorticity and external electromagnetic fields. We find an interesting phase in which the electric DC conductivity is negligible, while the anomalous conductivities turn out to be nonvanishing.

    ↳ hep-thcond-mat.str-elhep-phnucl-thJ.Phys.Conf.Ser.(2017)·4 citations
26. 26*

    Anomaly induced transport in non-anomalous currents

    Eugenio Megias🇪🇸

    Quantum anomalies are one of the subtlest properties of relativistic field theories. They give rise to non-dissipative transport coefficients in the hydrodynamic expansion. In particular a magnetic field can induce an anomalous current via the chiral magnetic effect. In this work we explore the possibility that anomalies can induce a chiral magnetic effect in non-anomalous currents as well. This effect is implemented through an explicit breaking of the symmetries.

    ↳ hep-thcond-mat.str-elhep-phnucl-thEPJ Web Conf.(2017)·4 citations
27. 27*

    Far-from-equilibrium energy flow and entanglement entropy

    Eugenio Megias🇪🇸

    The time evolution of the energy transport triggered in a strongly coupled system by a temperature gradient is holographically related to the evolution of an asymptotically AdS black brane. We study the far-from-equilibrium properties of such a system by using the AdS/CFT correspondence. In particular, we describe the appearance of a steady state, and study the information flow by computing the time evolution of the holographic entanglement entropy. Some universal properties of the quenching process are presented.

    ↳ hep-thcond-mat.stat-mechcond-mat.str-elhep-phEPJ Web Conf.(2017)·6 citations
28. 28*

    Don't choose theories: Normative inductive reasoning and the status of physical theories

    André C. R. Martins🇧🇷

    Evaluating theories in physics used to be easy. Our theories provided very distinct predictions. Experimental accuracy was so small that worrying about epistemological problems was not necessary. That is no longer the case. The underdeterminacy problem between string theory and the standard model for current possible experimental energies is one example. We need modern inductive methods for this problem, Bayesian methods or the equivalent Solomonoff induction. To illustrate the proper way to work with induction problems I will use the concepts of Solomoff induction to study the status of string theory. Previous attempts have focused on the Bayesian solution. And they run into the question of why string theory is widely accepted with no data backing it. Logically unsupported additions to the Bayesian method were proposed. I will show here that, by studying the problem from the point of view of the Solomonoff induction those additions can be understood much better. They are not ways to update probabilities. Instead, they are considerations about the priors as well as heuristics to attempt to deal with our finite resources. For the general problem, Solomonoff induction also makes it clear that there is no demarcation problem. Every possible idea can be part of a proper scientific theory. It is just the case that data makes some ideas extremely improbable. Theories where that does not happen must not be discarded. Rejecting ideas is just wrong.

    ↳ physics.hist-phgr-qchep-phphysics.data-an0 citations
29. 29*

    Non-Abelian bootstrap of primordial magnetism

    Poul Olesen🇩🇰

    We point out that a primordial magnetic field can be generated in the electroweak phase transition by a non-Abelian bootstrap, where the field is generated by currents of W's, which in turn are extracted from the vacuum by the magnetic field. This magnetic field is produced as a vortex condensate at the electroweak phase transition. It becomes stringy as a consequence of the dynamical evolution due to magnetohydrodynamics.

    ↳ hep-thastro-ph.HEhep-phmath-ph+13 citations
30. 30*

    Planck-scale constraints on anisotropic Lorentz and CPT invariance violations from optical polarization measurements

    Fabian Kislat🇺🇸 · Henric Krawczynski🇺🇸

    Lorentz invariance is the fundamental symmetry of Einstein's theory of special relativity, and has been tested to great level of detail. However, theories of quantum gravity at the Planck scale indicate that Lorentz symmetry may be broken at that scale motivating further tests. While the Planck energy is currently unreachable by experiment, tiny residual effects at attainable energies can become measurable when photons propagate over sufficiently large distances. The Standard-Model Extension (SME) is an effective field theory approach to describe low-energy effects of quantum gravity theories. Lorentz and CPT symmetry violating effects are introduced by adding additional terms to the Standard Model Lagrangian. These terms can be ordered by the mass dimension of the corresponding operator, and the leading terms of interest have dimension d = 5. Effects of these operators are a linear variation of the speed of light with photon energy, and a rotation of the linear polarization of photons quadratic in photon energy, as well as anisotropy. We analyzed optical polarization data from 72 AGN and GRBs and derived the first set of limits on all 16 coefficients of mass dimension d = 5 of the SME photon sector. Our constraints imply a lower limit on the energy scale of quantum gravity of $10^6$ times the Planck energy, severly limiting the phase space for any theory that predicts a rotation of the photon polarization quadratic in energy.

    ↳ astro-ph.HEgr-qchep-phPRD(2017)·38 citations
31. 31*

    An solvable three-body model in finite volume

    Peng Guo🇺🇸 · Vladimir Gasparian🇺🇸

    In this work, based on consideration of periodicity and asymptotic forms of wave function, we propose a novel approach to the solution of finite volume three-body problem by mapping a three-body problem into a higher dimensional two-body problem. The idea is demonstrated by an example of two light spinless particles and one heavy particle scattering in one spatial dimension. This 1D three-body problem resembles a two-body problem in two spatial dimensions mathematically, and quantization condition of 1D three-body problem is thus derived accordingly.

    ↳ hep-lathep-phPLB(2017)·98 citations
32. 32*

    (In)dependence of Theta in the Higgs Regime without Axions

    Mikhail Shifman🇺🇸 · Arkady Vainshtein🇺🇸

    We revisit the issue of the vacuum angle theta dependence in weakly coupled (Higgsed) Yang-Mills theories. Two most popular mechanisms for eliminating physical theta dependence are massless quarks and axions. Anselm and Johansen noted that the vacuum angle theta(EW), associated with the electroweak SU(2) in the Glashow-Weinberg-Salam model, is unobservable although all fermion fields obtain masses through Higgsing and there is no axion. We generalize this idea to a broad class of Higgsed Yang-Mills theories. In the second part we consider consequences of Grand Unification. We start from a unifying group, e.g. SU(5), at a high ultraviolet scale and evolve the theory down within the Wilson procedure. If on the way to infrared the unifying group is broken down into a few factors, all factor groups inherit one and the same theta angle -- that of the unifying group. We show that embedding the SM in SU(5) drastically changes the Anselm-Johansen conclusion: the electroweak vacuum angle theta(EW), equal to theta(QCD) becomes in principle observable in \Delta B=\Delta L =\pm 1 processes. We also note in passing that if the axion mechanism is set up above the unification scale, we have one and the same axion in the electroweak theory and QCD, and their impacts are interdependent.

    ↳ hep-thhep-phMod.Phys.Lett.A(2017)·13 citations
33. 33*

    Geometrical clusterization of Polyakov loops in SU(2) lattice gluodynamics

    A. Ivanytskyi · K. Bugaev · E. Nikonov · E.-M. Ilgenfritz · V. Sagun · I. Mishustin · V. Petrov · G. Zinovjev

    The liquid droplet formula is applied to an analysis of the properties of geometrical (anti)clusters formed in SU(2) gluodynamics by the Polyakov loops of the same sign. Using this approach, we explain the phase transition in SU(2) gluodynamics as a transition between two liquids during which one of the liquid droplets (the largest cluster of a certain Polyakov loop sign) experiences a condensation, while the droplet of another liquid (the next to the largest cluster of the opposite sign of Polyakov loop) evaporates. The clusters of smaller sizes form two accompanying gases, which behave oppositely to their liquids. The liquid droplet formula is used to analyze the size distributions of the gaseous (anti)clusters. The fit of these distributions allows us to extract the temperature dependence of surface tension and the value of Fisher topological exponent $\tau$ for both kinds of gaseous clusters. It is shown that the surface tension coeficient of gaseous (anti)clusters can serve as an order parameter of the deconfinement phase transition in SU(2) gluodynamics. The Fisher topological exponent $\tau$ of clusters and anticlusters is found to have the same value $1.806\pm 0.008$. This value disagrees with the famous Fisher droplet model, but it agrees well with an exactly solvable model of the nuclear liquid-gas phase transition. This finding may evidence for the fact that the SU(2) gluodynamics and this exactly solvable model of nuclear liquid-gas phase transition are in the same universality class.

    ↳ hep-lathep-phJ.Phys.Conf.Ser.(2017)·0 citations
34. 34*

    Study of $\eta$ and ${\eta }^{\prime }$ photoproduction at MAMI

    V. L. Kashevarov🇩🇪 · P. Ott🇩🇪 · S. Prakhov🇩🇪 · P. Adlarson🇩🇪 · F. Afzal🇩🇪 · Z. Ahmed🇨🇦 · C. S. Akondi🇺🇸 · J. R. M. Annand🇬🇧 · H. J. Arends🇩🇪 · R. Beck🇩🇪 · A. Braghieri🇮🇹 · W. J. Briscoe🇺🇸 and 78 other authors

    The reactions $\gamma p\to \eta p$ and $\gamma p\to {\eta }^{\prime }p$ have been measured from their thresholds up to the center-of-mass energy $W=1.96$GeV with the tagged-photon facilities at the Mainz Microtron, MAMI. Differential cross sections were obtained with unprecedented accuracy, providing fine energy binning and full production-angle coverage. A strong cusp is observed in the total cross section and excitation functions for $\eta$ photoproduction at the energies in vicinity of the ${\eta }^{\prime }$ threshold, $W=1896$MeV ($E_{\gamma }=1447$MeV). This behavior is explained in a revised $\eta$MAID isobar model by a significant branching of the $N(1895)1/2^{-}$ nucleon resonance to both, $\eta p$ and ${\eta }^{\prime }p$, confirming the existence and constraining the properties of this poorly known state.

    ↳ nucl-exhep-exhep-phPRL(2017)·77 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.