Mon·Jan 28, 2019Monday·January 28, 2019

1. 01*

   Gluon emission at small longitudinal momenta in the QCD effective action approach

   M.A. Braun🇷🇺 · M.I. Vyazovsky (Saint-Petersburg State University, Russia)🇷🇺

   In the framework of the QCD effective action the vertices of gluon emission in interaction of reggeons are studied in the limit of small longitudinal momenta of the emitted gluon. It is found that the vertices drastically simplify in this limit so that the gluon becomes emitted from a single reggeon coupled to the projectile and target via multireggeon vertices. Contribution from this kinematical region is studied for double and 2x2 elementary collisions inside the composite projectile and target.

   hep-phEPJC(2019)·1 citation
2. 02*

   Laser pulse-length effects in trident pair production

   Uwe Hernandez Acosta🇩🇪 · Burkhard Kämpfer🇩🇪

   Laser pulses facilitate multiphoton contributions to the trident pair production $e_L^{-}\to e_L^{-}+e_L^{-}+e_L^{+}$ , where the label $L$ indicates a laser field dressed electron ($e^{-}$) or positron ($e^{+}$). We isolate the impact of the pulse envelope in the trident S matrix element, formulated within the Furry picture, in leading order of a series expansion in the classical non-linearity parameter $a_0$. Generally, the Fourier transform of the envelope carries the information on the pulse length, which becomes an easily tractable function in the case of a ${\cos }^2$ pulse envelope. The transition to a monochromatic laser wave can be handled in a transparent manner, as also the onset of bandwidth effects for short pulses can be factorized out and studied separately.

   hep-phPlasma Phys.Control.Fusion(2019)·23 citations
3. 03*

   Neutrino physics with dark matter detectors

   Bhaskar Dutta🇺🇸 · Louis E. Strigari🇺🇸

   Direct dark matter detection experiments will soon be sensitive to neutrinos from astrophysical sources, including the Sun, the atmosphere, and supernova. This sets an important benchmark for these experiments, and opens up a new window in neutrino physics and astrophysics. The detection of these neutrinos will be complementary to accelerator and reactor-based experiments which study neutrinos over the same energy range. Here we review the physics and astrophysics that can be extracted from the detection of these neutrinos, highlighting the potential for identifying new physics in the form of light mediators that arise from kinetic mixing and hidden sectors, and $\sim$ eV-scale sterile neutrinos. We discuss how the physics reach of these experiments will complement searches for new physics at the LHC and dedicated neutrino experiments.

   hep-phastro-ph.HEAnn.Rev.Nucl.Part.Sci.(2019)·48 citations
4. 04*

   What does kinematical target mass sensitivity in DIS reveal about hadron structure?

   E. Moffat🇺🇸 · T. C. Rogers🇺🇸 · W. Melnitchouk🇺🇸 · N. Sato🇺🇸 · F. Steffens🇩🇪

   We study the role of purely external kinematical approximations in inclusive deep-inelastic lepton--hadron scattering within QCD factorization, and consider factorization with an exact treatment of the target hadron mass. We discuss how an observed phenomenological improvement obtained by accounting for target mass kinematics could be interpreted in terms of general properties of target structure, and argue that such an improvement implies a hierarchy of nonperturbative scales within the hadron.

   hep-phnucl-thPRD(2019)·21 citations
5. 05*

   NLL${}^{\prime }$ resummation of jet mass

   Marcel Balsiger🇨🇭 · Thomas Becher🇨🇭 · Ding Yu Shao🇨🇭

   Starting from a factorization theorem in effective field theory, we present resummed results for two non-global observables: the invariant-mass distribution of jets and the energy distribution outside jets. Our results include the full next-to-leading-order corrections to the hard, jet and soft functions and are implemented in a parton-shower framework which generates the renormalization-group running in the effective theory. The inclusion of these matching corrections leads to an improved description of the data and reduced theoretical uncertainties. They will have to be combined with two-loop running in the future, but our results are an important first step towards the higher-logarithmic resummation of non-global observables.

   hep-phJHEP(2019)·37 citations
6. 06*

   Dynamical systems and nonlinear transient rheology of the far-from-equilibrium Bjorken flow

   Alireza Behtash🇺🇸 · Syo Kamata🇺🇸 · M. Martinez🇺🇸 · Haosheng Shi🇺🇸

   In relativistic kinetic theory, the one-particle distribution function is approximated by an asymptotic perturbative power series in Knudsen number which is divergent. For the Bjorken flow, we expand the distribution function in terms of its moments and study their nonlinear evolution equations. The resulting coupled dynamical system can be solved for each moment consistently using a multi-parameter transseries which makes the constitutive relations inherit the same structure. A new non-perturbative dynamical renormalization scheme is born out of this formalism that goes beyond the linear response theory. We show that there is a Lyapunov function, aka dynamical potential, which is, in general, a function of the moments and time satisfying Lyapunov stability conditions along RG flows connected to the asymptotic hydrodynamic fixed point. As a result, the transport coefficients get dynamically renormalized at every order in the time-dependent perturbative expansion by receiving non-perturbative corrections present in the transseries. The connection between the integration constants and the UV data is discussed using the language of dynamical systems. Furthermore, we show that the first dissipative correction in the Knudsen number to the distribution function is not only determined by the known effective shear viscous term but also a new high energy non-hydrodynamic mode. It is demonstrated that the survival of this new mode is intrinsically related to the nonlinear mode-to-mode coupling with the shear viscous term. Finally, we comment on some possible phenomenological applications of the proposed non-hydrodynamic transport theory.

   ↳ hep-thhep-phnucl-thPRD(2019)·67 citations
7. 07*

   Spacetime Instability and Quantum Gravity as Low Energy Effective Field Theory

   Hiroki Matsui🇯🇵

   We discuss spacetime instability for effective field theories of quantum gravity. The effective action of gravity introduces infinite higher derivative curvature terms $R^2,R_{\mu \nu }{R}^{\mu \nu },R_{\mu \nu \kappa \lambda }{R}^{\mu \nu \kappa \lambda }\dots$. Although these higher derivative curvature terms are indispensable to construct the self-consistent renormalizable theory of quantum gravity, they lead to several pathologies. We clearly show that even if they are written as the Planck-suppressed operators they lead to serious consequences and and de Sitter or radiation-dominated Universe is highly unstable. We show that the couplings of these higher derivative curvatures must satisfy $\left|a_{1,2,3}\right|\gtrsim 10^{118}$ to be consistent with the cosmological observations. Thus, the standard effective field theories of quantum gravity fail to describe the observed Universe unless introducing a specific technique dealing with the higher derivative curvature terms.

   ↳ hep-thastro-ph.COgr-qchep-phGen.Rel.Grav.(2022)·5 citations
8. 08*

   Time-dependent $NAd{S}_2$ holography with applications

   Lata Kh Joshi🇮🇳 · Ayan Mukhopadhyay🇮🇳 · Alexander Soloviev🇦🇹

   We develop a method for obtaining exact time-dependent solutions in Jackiw-Teitelboim gravity coupled to non-conformal matter and study consequences for $NAd{S}_2$ holography. We study holographic quenches in which we find that the black hole mass increases. A semi-holographic model composed of an infrared $NAd{S}_2$ holographic sector representing the mutual strong interactions of trapped impurities confined at a spatial point is proposed. The holographic sector couples to the position of a displaced impurity acting as a self-consistent boundary source. This effective $0+1-$dimensional description has a total conserved energy. Irrespective of the initial velocity of the particle, the black hole mass initially increases, but after the horizon runs away to infinity in the physical patch, the mass vanishes in the long run. The total energy is completely transferred to the kinetic energy or the self-consistent confining potential energy of the impurity. For initial velocities below a critical value determined by the mutual coupling, the black hole mass changes sign in finite time. Above this critical velocity, the initial condition of the particle can be retrieved from the $SL(2,R)$ invariant exponent that governs the exponential growth of the bulk gravitational $SL(2,R)$ charges at late time.

   ↳ hep-thgr-qchep-phPRD(2020)·13 citations
9. 09*

   $D$ meson Semileptonic Decay Form Factors at $q^2=0$

   Ruizi Li🇺🇸 · A. Bazavov🇺🇸 · C. W. Bernard🇺🇸 · C. DeTar🇺🇸 · Daping Du🇺🇸 · A. X. El-Khadra🇺🇸 · E. Gámiz🇪🇸 · Steven Gottlieb🇺🇸 · U. M. Heller🇺🇸 · J. Komijani🇬🇧 · A. S. Kronfeld🇺🇸 · J. Laiho🇺🇸 and 8 other authors

   We discuss preliminary results for the vector form factors $f_{+}^{\{\pi ,K\}}$ at zero-momentum transfer for the decays $D\to \pi \ell \nu$ and $D\to K\ell \nu$ using MILC's $N_f=2+1+1$ HISQ ensembles at four lattice spacings, $a\approx 0.042,0.06,0.09$, and 0.12 fm, and various HISQ quark masses down to the (degenerate) physical light quark mass. We use the kinematic constraint $f_{+}(q^2)=f_0(q^2)$ at $q^2=0$ to determine the vector form factor from our study of the scalar current, which yields $f_0(0)$. Results are extrapolated to the continuum physical point in the framework of hard pion/kaon SU(3) heavy-meson-staggered $\chi$PT and Symanzik effective theory. Our calculation improves upon the precision achieved in existing lattice-QCD calculations of the vector form factors at $q^2=0$. We show the values of the CKM matrix elements $|V_{cs}|$ and $|V_{cd}|$ that we would obtain using our preliminary results for the form factors together with recent experimental results, and discuss the implications of these values for the second row CKM unitarity.

   ↳ hep-lathep-phPoS(2019)·17 citations
10. 10*

    The nucleon resonance structure from exclusive ${\pi }^{+}{\pi }^{-}p$ photo-/electroproduction off protons

    V.D. Burkert🇺🇸 · V.I. Mokeev🇺🇸 · B.S. Ishkhanov🇷🇺

    The results on the photo- and electroexcitation amplitudes of most nucleon resonances in the mass range up to 2.0 GeV determined from the CLAS experimental data on exclusive ${\pi }^{+}{\pi }^{-}p$ photo-/electroproduction off protons in collaboration between the Jefferson Lab and Moscow State University are presented. The first and only available results on electroexcitation amplitudes from CLAS in a wide range of photon virtualities $Q^2$ $<$ 5.0 GeV${}^2$ revealed the nucleon resonance structure as a complex interplay between the inner core of three dressed quarks and external meson-baryon cloud. These results shed light on the strong QCD dynamics which underlines the generation of excited nucleon states of different structural features from confined quarks and gluons. The future prospects of these studies in the new era of experiments with the CLAS12 detector, which started successfully in Spring of 2018, are outlined.

    ↳ nucl-exhep-phMoscow Univ.Phys.Bull.(2019)·16 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.