HEP Phenomenology·hep-ph

Thu·Feb 22, 2018Thursday·February 22, 2018

14 papers—10 primary·4 cross-listed·reconstructed*

01*
Lorentz-violating contributions to the nuclear Schiff moment and nuclear EDM
Jonas B. Araujo🇧🇷 · Rodolfo Casana🇧🇷 · Manoel M. Ferreira Jr🇧🇷
In the context of an atom endowed with nuclear electric dipole moment (EDM), we consider the effects on the Schiff moment of $C P T$ -even Lorentz-violating (LV) terms that modify the Coulomb potential. First, we study the modifications on the Schiff moment when the nucleus interacts with the electronic cloud by means of a Coulomb potential altered only by the $P$ -even LV components. Next, by supposing the existence of an additional intrinsic LV EDM generated by other LV sources, we assess the corrections to the Schiff moment when the interaction nucleus-electrons runs mediated by a Coulomb potential modified by both the $P$ -odd and $P$ -even LV components. We then use known estimates and EDM measurements to discuss upper bounds on the new Schiff moment components and the possibility of an intrisic nuclear EDM component ascribed to LV effects.
hep-phhep-thnucl-thPRD(2018)·11 citations
02*
Neutrino astrophysics and its connections to nuclear physics
Maria Cristina Volpe🇫🇷
We highlight recent developments in neutrino astrophysics. We discuss some of the connections with nuclear physics.
hep-phnucl-exnucl-thJ.Phys.Conf.Ser.(2018)·1 citation
03*
ALP production through non-linear Compton scattering in intense fields
Barry M. Dillon🇬🇧 · Ben King🇬🇧
We derive production yields for massive pseudo-scalar and scalar axion-like-particles (ALPs), through non-linear Compton scattering of an electron in the background of low- and high-intensity electromagnetic fields. In particular, we focus on electromagnetic fields from Gaussian plane wave laser pulses. A detailed study of the angular distributions and effects of the scalar and pseudo-scalar masses is presented. It is shown that ultra-relativistic seed electrons can be used to produce scalars and pseudo-scalars with masses up to the order of the electron mass. We briefly discuss future applications of this work towards lab-based searches for light beyond-the-Standard-Model particles.
hep-phEPJC(2018)·27 citations
04*
Electron-seeded ALP production and ALP decay in an oscillating electromagnetic field
B. King🇬🇧
Certain models involving ALPs (axion-like-particles) allow for the coupling of scalars and pseudoscalars to fermions. A derivation of the total rate for production of massive scalars and pseudoscalars by an electron in a monochromatic, circularly-polarised electromagnetic background is presented. In addition, a derivation and the total rate for the decay of massive scalars and pseudoscalars into electron-positron pairs in the same electromagnetic background is given. We conclude by approximating the total yield of ALP production for a typical laser-particle experimental scenario.
hep-phphysics.opticsphysics.plasm-phPLB(2018)·20 citations
05*
Constraining the Higgs self couplings at $e^{+} e^{-}$ colliders
Fabio Maltoni🇧🇪 · Davide Pagani🇩🇪 · Xiaoran Zhao🇧🇪
We study the sensitivity to the shape of the Higgs potential of single, double, and triple Higgs production at future $e^{+} e^{-}$ colliders. Physics beyond the Standard Model is parameterised through the inclusion of higher-dimensional operators $(Φ^{†} Φ - v^{2} /2)^{n} / Λ^{(2 n - 4)}$ with $n = 3, 4$ , which allows a consistent treatment of independent deviations of the cubic and quartic self couplings beyond the tree level. We calculate the effects induced by a modified potential up to one loop in single and double Higgs production and at the tree level in triple Higgs production, for both $Z$ boson associated and $W$ boson fusion production mechanisms. We consider two different scenarios. First, the dimension six operator provides the dominant contribution (as expected, for instance, in a linear effective-field-theory(EFT)); we find in this case that the corresponding Wilson coefficient can be determined at $O (10%)$ accuracy by just combining accurate measurements of single Higgs cross sections at $s^=$ 240-250 GeV and double Higgs production in $W$ boson fusion at higher energies. Second, both operators of dimension six and eight can give effects of similar order, i.e., independent quartic self coupling deviations are present. Constraints on Wilson coefficients can be best tested by combining measurements from single, double and triple Higgs production. Given that the sensitivity of single Higgs production to the dimension eight operator is presently unknown, we consider double and triple Higgs production and show that combining their information colliders at higher energies will provide first coarse constraints on the corresponding Wilson coefficient.
hep-phJHEP(2018)·72 citations
06*
Angular and polarization trails from effective interactions of Majorana neutrinos at the LHeC
Lucía Duarte🇺🇾 · Gabriel Zapata🇦🇷 · Oscar A. Sampayo🇦🇷
We study the possibility of the LHeC facility to disentangle different new physics contributions to the production of heavy sterile Majorana neutrinos in the lepton number violating channel $e^{-} p \to l_{j}^{+} + 3 j e t s$ ( $l_{j} \equiv e, μ$ ). This is done investigating the angular and polarization trails of effective operators with distinct Dirac-Lorentz structure contributing to the Majorana neutrino production, which parameterize new physics from a higher energy scale. We study an asymmetry in the angular distribution of the final anti-lepton and the initial electron polarization effect on the number of signal events produced by the vectorial and scalar effective interactions, finding both analyses could well separate their contributions.
hep-phEPJC(2018)·23 citations
07*
Generalized Wandzura Wilczek Relations and Orbital Angular Momentum
Simonetta Liuti🇺🇸 · Michael Engelhardt🇺🇸 · Abha Rajan🇺🇸
New Lorentz Invariance Relations (LIRs) were presented between twist-three Generalized Parton Distributions (GPDs) and transverse momentum, $k_{T}$ , moments of twist-two Generalized Transverse Momentum-Dependent Distributions (GTMDs). By implementing both these LIRs and the QCD Equations of Motion in the quark quark correlation function, we generated a new series of Wandzura Wilczek (WW) relations in the off-forward sector. Two of these WW relations take on a particularly interesting physical meaning in that they provide a clear interpretation of the QCD structure of Orbital Angular Momentum (OAM) in the nucleon. In particular, they provide a solution to the outstanding puzzle of how OAM could be simultaneously described by twist-two GTMDs and twist-three GPDs. Additional relations were discussed, in particular, for the helicity configurations that can be detected analyzing specific spin asymmetries: one corresponding to a longitudinally polarized quark in an unpolarized proton, associated with spin-orbit correlations, and one for transverse proton polarization, as a generalization of the relation obeyed by the $g_{2}$ structure function; finally, we defined a relation connecting the off-forward extension of the Sivers function to an off-forward Qiu-Sterman term.
hep-phPoS(2018)·0 citations
08*
The electromagnetic multipole moments of the charged open-flavor $Z_{c ˉ q}$ states
K. Azizi🇹🇷 · U. Ozdem🇹🇷
The electromagnetic multipole moments of the open-flavor $Z_{c ˉ q}$ states are investigated by assuming a diquark-antidiquark picture for their internal structure and quantum numbers $J^{P C} = 1^{+-}$ for their spin-parity. In particular, their magnetic and quadrupole moments are extracted in the framework of light-cone QCD sum rule by the help of the photon distribution amplitudes. The electromagnetic multipole moments of the open-flavor $Z_{c ˉ q}$ states are important dynamical observables, which encode valuable information on their underlying structure. The results obtained for the magnetic moments of different structures are considerably large and can be measured in future experiments. We obtain very small values for the quadrupole moments of $Z_{c ˉ q}$ states indicating a nonspherical charge distribution.
hep-phhep-exhep-latJ.Phys.G(2018)·13 citations
09*
Dark quarkonium formation in the early universe
Michael Geller🇺🇸 · Sho Iwamoto🇮🇱 · Gabriel Lee🇮🇱 · Yael Shadmi🇮🇱 · Ofri Telem🇺🇸
The relic abundance of heavy stable particles charged under a confining gauge group can be depleted by a second stage of annihilations near the deconfinement temperature. This proceeds via the formation of quarkonia-like states, in which the heavy pair subsequently annihilates. The size of the quarkonium formation cross section was the subject of some debate. We estimate this cross section in a simple toy model. The dominant process can be viewed as a rearrangement of the heavy and light quarks, leading to a geometric cross section of hadronic size. In contrast, processes in which only the heavy constituents are involved lead to mass-suppressed cross sections. These results apply to any scenario with bound states of sizes much larger than their inverse mass, such as U(1) models with charged particles of different masses, and can be used to construct ultra-heavy dark-matter models with masses above the naïve unitarity bound. They are also relevant for the cosmology of any stable colored relic.
hep-phJHEP(2018)·44 citations
10*
Supersymmetric Flaxion
Yohei Ema🇯🇵 · Daisuke Hagihara🇯🇵 · Koichi Hamaguchi🇯🇵 · Takeo Moroi🇯🇵 · Kazunori Nakayama🇯🇵
Recently, a new minimal extension of the Standard Model has been proposed, where a spontaneously broken, flavor-dependent global U(1) symmetry is introduced. It not only explains the hierarchical flavor structure in the quark and lepton sector, but also solves the strong CP problem by identifying the Nambu-Goldstone boson as the QCD axion, which we call flaxion. In this work, we consider supersymmetric extensions of the flaxion scenario. We study the CP and flavor violations due to supersymmetric particles, the effects of R-parity violations, the cosmological gravitino and axino problems, and the cosmological evolution of the scalar partner of the flaxion, sflaxion. We also propose an attractor-like inflationary model where the flaxion multiplet contains the inflaton field, and show that a consistent cosmological scenario can be obtained, including inflation, leptogenesis, and dark matter.
hep-phJHEP(2018)·26 citations
11*
Electron-Phonon Systems on a Universal Quantum Computer
Alexandru Macridin🇺🇸 · Panagiotis Spentzouris🇺🇸 · James Amundson🇺🇸 · Roni Harnik🇺🇸
We present an algorithm that extends existing quantum algorithms for simulating fermion systems in quantum chemistry and condensed matter physics to include bosons in general and phonons in particular. We introduce a qubit representation for the low-energy subspace of phonons which allows an efficient simulation of the evolution operator of the electron-phonon systems. As a consequence of the Nyquist-Shannon sampling theorem, the phonons are represented with exponential accuracy on a discretized Hilbert space with a size that increases linearly with the cutoff of the maximum phonon number. The additional number of qubits required by the presence of phonons scales linearly with the size of the system. The additional circuit depth is constant for systems with finite-range electron-phonon and phonon-phonon interactions and linear for long-range electron-phonon interactions. Our algorithm for a Holstein polaron problem was implemented on an Atos Quantum Learning Machine (QLM) quantum simulator employing the Quantum Phase Estimation method. The energy and the phonon number distribution of the polaron state agree with exact diagonalization results for weak, intermediate and strong electron-phonon coupling regimes.
↳ quant-phcond-mat.str-elhep-phPRL(2018)·143 citations
12*
Mean field quantization of effective string
Yuri Makeenko🇷🇺
I describe the recently proposed quantization of bosonic string about the mean-field ground state, paying special attention to the differences from the usual quantization about the classical vacuum which turns out to be unstable for d>2. In particular, the string susceptibility index $γ_{str}$ is 1 in the usual perturbation theory, but equals 1/2 in the mean-field approximation that applies for 2<d<26. I show that the total central charge equals zero in the mean-field approximation and argue that fluctuations about the mean field do not spoil conformal invariance.
↳ hep-thhep-phJHEP(2018)·5 citations
13*
Exact Correlators from Conformal Ward Identities in Momentum Space and the Perturbative $T J J$ Vertex
Claudio Coriano🇮🇹 · Matteo Maria Maglio🇮🇹
We present a general study of 3-point functions of conformal field theory in momentum space, following a reconstruction method for tensor correlators, based on the solution of the conformal Ward identities (CWI' s), introduced in recent works by Bzowski, McFadden and Skenderis (BMS). We investigate and detail the structure of the CWI's, their non-perturbative solutions and the transition to momentum space, comparing them to perturbation theory by taking QED as an example. We then proceed with an analysis of the $T J J$ correlator, presenting independent and detailed re-derivations of the conformal equations in the reconstruction method of BMS, originally formulated using a minimal tensor basis in the transverse traceless sector. A careful comparison with a second basis introduced in previous studies shows that this correlator is affected by one anomaly pole in the graviton (T) line, induced by renormalization. The result shows that the origin of the anomaly, in this correlator, should be necessarily attributed to the exchange of a massless effective degree of freedom. Our results are then exemplified in massless QED at one-loop in $d$ -dimensions, expressed in terms of perturbative master integrals. An independent analysis of the Fuchsian character of the solutions, which bypasses the 3K integrals, is also presented. We show that the combination of field theories at one-loop - with a specific field content of degenerate massless scalar and fermions - is sufficient to generate the complete non-perturbative solution, in agreement with a previous study in coordinate space. The result shows that free conformal field theories, in specific dimensions, arrested at one-loop, reproduce the general result for the $T J J$ . Analytical checks of this correspondence are presented in $d = 3, 4$ and $5$ spacetime dimensions[..].
↳ hep-thhep-phNPB(2019)·62 citations
14*
Light Primordial Exotic Compact Objects as All Dark Matter
Martti Raidal🇪🇪 · Sergey Solodukhin🇨🇭 · Ville Vaskonen🇪🇪 · Hardi Veermäe🇪🇪
The radiation emitted by horizonless exotic compact objects (ECOs), such as wormholes, 2-2-holes, fuzzballs, gravastars, boson stars, collapsed polymers, superspinars etc., is expected to be strongly suppressed when compared to the radiation of black holes. If large primordial curvature fluctuations collapse into such objects instead of black holes, they do not evaporate or evaporate much slower than black holes and could thus constitute all of the dark matter with masses below $M < 1 0^{- 16} M_{⊙} .$ We reevaluate the relevant experimental constraints for light ECOs in this mass range and show that very large new parameter space down to ECO masses $M \sim 10 TeV$ opens up for light primordial dark matter. A new dedicated experimental program is needed to test this mass range of primordial dark matter.
↳ astro-ph.COgr-qchep-phPRD(2018)·32 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.