Nuclear Theory·nucl-th

Friday·April 19, 2019

9 papers—5 primary·4 cross-listed

06
[Submitted on 29 Jan 2019] (cross-list from hep-ph)
Rare hyperon decays with missing energy
Jusak Tandean🇹🇼
We explore the strangeness-changing decays of the lightest hyperons into another baryon plus missing energy within and beyond the standard model (SM). In the SM these processes arise from the loop-induced quark transition $s \to d ν ν ˉ$ and their branching fractions are estimated to be less than $1 0^{- 11}$ . In the presence of new physics (NP) the rates of these hyperon decays with missing energy could increase significantly with respect to the SM expectations because of modifications to the SM process or contributions from additional modes with new invisible particles. Adopting a model-independent approach and taking into account constraints from the kaon sector, we find that the current data on $K \to π ν ν ˉ$ do not permit sizable NP impact on the hyperon decays via underlying operators having mainly parity-even quark parts. In contrast, NP operators with primarily parity-odd quark parts are much less restricted by the existing bounds on $K \to invisible$ and $K \to π π ν ν ˉ$ and consequently could produce substantially amplifying effects on the hyperon modes. Their NP-enhanced branching fractions could reach levels potentially observable in the ongoing BESIII experiment.
Comments:
16 pages, no figure, slightly enlarged, references added, typos corrected, matches publication
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
1901.10447 [pdf]
JHEP(2019)·21 citations
07
[Submitted on 18 Apr 2019] (cross-list from hep-th)
Effective gauge theories of superfluidity with topological order
Yuji Hirono🇰🇷 · Yuya Tanizaki🇺🇸
We discuss the low-energy dynamics of superfluidity with topological order in $(3 + 1)$ spacetime dimensions. We generalize a topological $B F$ theory by introducing a non-square $K$ matrix, and this generalized $B F$ theory can describe massless Nambu-Goldstone bosons and anyonic statistics between vortices and quasiparticles. We discuss the general structure of discrete and continuous higher-form symmetries in this theory, which can be used to classify quantum phases. We describe how to identify the appearance of topological order in such systems and discuss its relation to a mixed 't Hooft anomaly between discrete higher-form symmetries. We apply this framework to the color-flavor locked phase of dense QCD, which shows anyonic particle-vortex statistics while no topological order appears. An explicit example of superfluidity with topological order is discussed.
Comments:
34 pages, no figure; v2: added discussions and Appendix D
Subjects:
High Energy Physics — Theory (hep-th); Strongly Correlated Electrons (cond-mat.str-el); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1904.08570 [pdf]
JHEP(2019)·24 citations
08
[Submitted on 18 Apr 2019] (cross-list from hep-ph)
Nonlinear flavor development of a two-dimensional neutrino gas
Joshua D. Martin🇺🇸 · Sajad Abbar🇺🇸 · Huaiyu Duan🇺🇸
We present a numerical survey of the nonlinear flavor development of dense neutrino gases. This study is based on the stationary, two-dimensional ( $x$ and $z$ ), two-beam, monochromatic neutrino line model with a periodic boundary condition along the $x$ direction. Similar to a previous work, we find that small-scale flavor structures can develop in a neutrino gas even if the physical conditions are nearly homogeneous along the $x$ axis initially. The power diffusion from the large-scale to small-scale structures increases with the neutrino density and helps to establish a semi-exponential dependence of the magnitudes of the Fourier moments on the corresponding wave numbers. The overall flavor conversion probabilities in the neutrino gases with small initial sinusoidal perturbations reach certain equilibrium values at large distances which are mainly determined by the neutrino-antineutrino asymmetry. Similar phenomena also exist in a neutrino gas with a localized initial perturbation, albeit only inside an expanding flavor conversion region. Our work suggests that a statistical treatment may be possible for the collective flavor oscillations of a dense neutrino gas in a multi-dimensional environment.
Comments:
10 pages, 5 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)
arXiv:
1904.08877 [pdf]
PRD(2019)·29 citations
09
[Submitted on 18 Apr 2019] (cross-list from astro-ph.HE)
Constraining the equation of state of high-density cold matter using nuclear and astronomical measurements
M. Coleman Miller (University of Maryland) · Cecilia Chirenti (UFABC) · Frederick K. Lamb (University of Illinois)
The increasing richness of data related to cold dense matter, from laboratory experiments to neutron-star observations, requires a framework for constraining the properties of such matter that makes use of all relevant information. Here, we present a rigorous but practical Bayesian approach that can include diverse evidence, such as nuclear data and the inferred masses, radii, tidal deformabilities, moments of inertia, and gravitational binding energies of neutron stars. We emphasize that the full posterior probability distributions of measurements should be used rather than, as is common, imposing a cut on the maximum mass or other quantities. Our method can be used with any parameterization of the equation of state (EOS). We use both a spectral parameterization and a piecewise polytropic parameterization with variable transition densities to illustrate the implications of current measurements and show how future measurements in many domains could improve our understanding of cold catalyzed matter. We find that different types of measurements will play distinct roles in constraining the EOS in different density ranges. For example, better symmetry energy measurements will have a major influence on our understanding of matter somewhat below nuclear saturation density but little influence above that density. In contrast, precise radius measurements or multiple tidal deformability measurements of the quality of those from GW170817 or better will improve our knowledge of the EOS over a broader density range.
Comments:
31 pages, 14 figures, accepted in The Astrophysical Journal
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc); Nuclear Theory (nucl-th)
arXiv:
1904.08907 [pdf]
122 citations

Affiliations

first authorsco-authorsvia INSPIRE

Rare hyperon decays with missing energy

Effective gauge theories of superfluidity with topological order

Nonlinear flavor development of a two-dimensional neutrino gas

Constraining the equation of state of high-density cold matter using nuclear and astronomical measurements

Affiliations