Nuclear Theory·nucl-th

Tuesday·November 12, 2019

11 papers—5 primary·6 cross-listed

06
How well do we know neutrino-electron scattering? EFT approach
Oleksandr Tomalak🇺🇸
We determine the effective theory of neutrino-electron and neutrino-quark scattering and provide the most precise up-to-date prediction for neutrino-electron scattering cross sections quantifying errors for the first time to be of order $0.2 - 0.4 %$ . Radiative corrections in the theory with electron and neutrinos only involve three effective couplings. One is the Fermi constant which is known with sub-ppm accuracy. Another one has a small error of order $0.02 %$ . The uncertainty of the third one is limited by the knowledge of hadronic contributions to charge-isospin vector-vector correlation function.
↳ hep-phhep-exnucl-exnucl-thPoS(2020)·1 citation
07
Transverse-Momentum-Dependent Parton Distribution Functions from Large-Momentum Effective Theory
Xiangdong Ji🇨🇳 · Yizhuang Liu🇨🇳 · Yu-Sheng Liu🇨🇳
We show that transverse-momentum-dependent parton distribution functions (TMDPDFs), important non-perturbative quantities for describing the properties of hadrons in high-energy scattering processes such as Drell-Yan and semi-inclusive deep-inelastic scattering with observed small transverse momentum, can be obtained from Euclidean QCD calculations in the framework of large-momentum effective theory (LaMET). We present a LaMET factorization of the Euclidean quasi-TMDPDFs in terms of the physical TMDPDFs and off-light-cone soft function at leading order in $1/ P^{z}$ expansion, with the perturbative matching coefficient satisfying a renormalization group equation. We also discuss the implementation in lattice QCD with finite-length gauge links as well as the rapidity-regularization-independent factorization for Drell-Yan cross section.
↳ hep-phhep-exhep-latnucl-ex+1PLB(2020)·104 citations
08
Dark photon manifestation in the triplet-like QED processes $γ + ℓ_{i} \to ℓ_{j}^{+} ℓ_{j}^{-} + ℓ_{i}$ , $i \neq = j,$ $i = e, μ,$ $j = e, μ, τ$
G.I. Gakh🇺🇦 · M.I. Konchatnij🇺🇦 · N.P. Merenkov🇺🇦 · E. Tomasi-Gustafsson🇫🇷
The triplet-like QED processes $γ + ℓ_{i} \to ℓ_{j}^{+} ℓ_{j}^{-} + ℓ_{i}$ with $i \neq = j,$ and $i = e, μ,$ $j = e, μ, τ$ has been investigated as the reactions where a dark photon, $A^{'}$ , is produced as a virtual state with subsequent decay into a $ℓ_{j}^{+} ℓ_{j}^{-} -$ -pair. This effect arises due to the so-called kinetic mixing and is characterized by the small parameter $ϵ$ describing the coupling strength relative to the electric charge $e$ . The main advantage of searching $A^{'}$ in these processes is that the background to the $A^{'}$ signal is pure QED. Concerning $A^{'}$ , we consider its contribution in the Compton-type diagrams only since, in this case, the virtual dark photon has time-like nature and its propagator has the Breit-Wigner form. So, near the resonance, $A^{'}$ can manifest itself. The contribution of $A^{'}$ in the Borsellino diagrams is negligible since, in this case, the virtual dark photon is space-like, the $A^{'}$ propagator does not peak and the effect is proportional, at least, to $ϵ^{2}$ . We calculate the distributions over the invariant mass of the produced $ℓ_{j}^{+} ℓ_{j}^{-} -$ pair and search for the kinematical region where the Compton-type diagrams contribution is not suppressed with respect to the Borsellino ones. The value of the parameter $ϵ$ is estimated as a function of the dark photon mass for a given number of events.
↳ hep-phhep-exnucl-thPRD(2020)·1 citation
09
Long-range electroweak amplitudes of single hadrons from Euclidean finite-volume correlation functions
Raúl A. Briceño🇺🇸 · Zohreh Davoudi🇺🇸 · Maxwell T. Hansen🇨🇭 · Matthias R. Schindler🇺🇸 · Alessandro Baroni🇺🇸
A relation is presented between single-hadron long-range matrix elements defined in a finite Euclidean spacetime, and the corresponding infinite-volume Minkowski amplitudes. This relation is valid in the kinematic region where any number of two-hadron states can simultaneously go on shell, so that the effects of strongly-coupled intermediate channels are included. These channels can consist of non-identical particles with arbitrary intrinsic spins. The result accommodates general Lorentz structures as well as non-zero momentum transfer for the two external currents inserted between the single-hadron states. The formalism, therefore, generalizes the work by Christ et al.~[Phys.Rev. D91 114510 (2015)], and extends the reach of lattice quantum chromodynamics (QCD) to a wide class of new observables beyond meson mixing and rare decays. Applications include Compton scattering of the pion ( $π γ^{⋆} \to [π π, K K] \to π γ^{⋆}$ ), kaon ( $K γ^{⋆} \to [π K, η K] \to K γ^{⋆}$ ) and nucleon ( $N γ^{⋆} \to N π \to N γ^{⋆}$ ), as well as double- $β$ decays, and radiative corrections to the single- $β$ decay, of QCD-stable hadrons. The framework presented will further facilitate generalization of the result to studies of nuclear amplitudes involving two currents from lattice QCD.
↳ hep-lathep-phnucl-thPRD(2020)·51 citations
10
Radiative corrections in proton--antiproton annihilation to electron-positron and their application to the PANDA experiment
Yu.M. Bystritskiy🇷🇺 · V.A. Zykunov🇷🇺 · A. Dbeyssi🇩🇪 · M. Zambrana🇩🇪 · F. Maas🇩🇪 · E. Tomasi-Gustafsson🇫🇷
Radiative corrections to the annihilation of proton--antiproton into electron--positron are revisited, including virtual and real (soft and hard) photon emission. This issue is relevant for the time-like form factors measurements planned at the PANDA experiment at the FAIR facility, in next future. The relevant formulas are given. A stand-alone Monte-Carlo integrator is developed on the basis of the calculated radiative cross section and its application to the PANDA experiment is illustrated.
↳ hep-phhep-exnucl-thEPJA(2020)·2 citations
11
The Rayleigh Bubble in Quark Matter under a Strong Magnetic Field
B.O. Kerbikov · M.S. Lukashov
The transition of QGP from fluid-dynamical regime to freeze-out is accompanied by the onset of instabilities. In the present paper we investigate the impact of the magnetic field on the Rayleigh instability. We show that extremely strong field generated in peripheral heavy ion collisions has an insignificant influence on the Rayleigh bubble dynamics. Magnetic "friction" turns out to be much weaker than the viscous one.
↳ hep-phnucl-thPRD(2020)·1 citation

Affiliations

first authorsco-authorsvia INSPIRE

How well do we know neutrino-electron scattering? EFT approach

Transverse-Momentum-Dependent Parton Distribution Functions from Large-Momentum Effective Theory

Dark photon manifestation in the triplet-like QED processes γ+ℓi​→ℓj+​ℓj−​+ℓi​, i=j, i=e,μ, j=e,μ,τ

Long-range electroweak amplitudes of single hadrons from Euclidean finite-volume correlation functions

Radiative corrections in proton--antiproton annihilation to electron-positron and their application to the PANDA experiment

The Rayleigh Bubble in Quark Matter under a Strong Magnetic Field

Affiliations

Dark photon manifestation in the triplet-like QED processes $γ + ℓ_{i} \to ℓ_{j}^{+} ℓ_{j}^{-} + ℓ_{i}$ , $i \neq = j,$ $i = e, μ,$ $j = e, μ, τ$