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Y. Kuang

Publications and source records attributed to Y. Kuang.

8 recordsLinked to original sources

Neutron radius determination of 133Cs and its impact on the interpretation of CEvNS-CsI measurement

Proton-$^{133}$Cs elastic scattering at low momentum transfer is performed using an in-ring reaction technique at the Cooler Storage Ring at the Heavy Ion Research Facility in Lanzhou. Recoil protons from the elastic collisions between the internal H$_2$-gas target and the circulating $^{133}$Cs ions at 199.4 MeV/u are detected by a silicon-strip detector. The matter radius of $^{133}$Cs is deduced by describing the measured differential cross sections using the Glauber model. Employing the adopted proton distribution radius, a point-neutron radius of 4.86(21) fm for $^{133}$Cs is obtained. With the newly determined neutron radius, the weak mixing angle sin$^2 \theta_W$ is independently extracted to be 0.227(28) by fitting the coherent elastic neutrino-nucleus scattering data. Our work limits the sin$^2 \theta_W$ value in a range smaller than the ones proposed by the previous independent approaches, and would play an important role in searching new physics via the high precision CE$\nu$NS-CsI cross section data in the near future.

nucl-ex

Extracting neutron skin from elastic proton-nucleus scattering with deep neural network

Based on the relativistic impulse approximation of proton-nucleus elastic scattering theory, the nucleon density distribution and neutron skin thickness of $^{48}$Ca are estimated via the deep learning method. The neural-network-generated densities are mainly compressed to be lower inside the nucleus compared with the results from the relativistic PC-PK1 density functional, resulting in a significant improvement on the large-angle scattering observables, both for the differential cross section and analyzing power. The neutron skin thickness of $^{48}$Ca is captured to be 0.211(11) fm. The relatively thicker neutron skin is deemed reasonable from the perspective of density functional analysis.

nucl-th

On Galois-Gauss sums and the square root of the inverse different

We discuss a possible generalisation of a conjecture of Bley, Burns and Hahn concerning the relation between the second Adams-operator twisted Galois-Gauss sums of weakly ramified Artin characters and the square root of the inverse different of finite, odd degree, Galois extensions of number fields, to the setting of all finite Galois extensions of number fields for which a square root of the inverse different exists. We also extend the key methods and results of Bley, Burns and Hahn to this more general setting and, by combining these methods with a recent result of Agboola, Burns, Caputo and the present author concerning Artin root numbers of twisted irreducible symplectic characters, we provide new insight into a conjecture of Erez concerning the Galois structure of the square root of the inverse different.

math.NT

On the Galois-Gauss sums of weakly ramified characters

Bley, Burns and Hahn used relative algebraic $K$-theory methods to formulate a precise conjectural link between the (second Adams-operator twisted) Galois-Gauss sums of weakly ramified Artin characters and the square root of the inverse different of finite, odd degree, Galois extensions of number fields. We provide concrete new evidence for this conjecture in the setting of extensions of odd prime-power degree by using a refined version of a well-known result of Ullom.

math.NT

On the square root of the inverse different

Let N/F be a finite, normal extension of number fields with Galois group G. Suppose that N/F is weakly ramified, and that the square root A(N/F) of the inverse different of N.F is defined. (This latter condition holds if, for example, G is of odd order.) B. Erez has conjectured that the class (A(N/F)) of A(N/F) in the locally free class group Cl(ZG) of ZG is equal to the Cassou-Nogues-Frohlich root number class W(N/F) attached to N/F. We establish a precise formula for (A(N/F)) - W(N/F) in terms of the signs of certain symplectic Galois-Gauss sums whenever N/F is tame and (A(N/F)) is defined. We thereby show that, in general, (A(N/F)) is not equal to W(N/F).

math.NT

A straw drift chamber spectrometer for studies of rare kaon decays

We describe the design, construction, readout, tests, and performance of planar drift chambers, based on 5 mm diameter copperized Mylar and Kapton straws, used in an experimental search for rare kaon decays. The experiment took place in the high-intensity neutral beam at the Alternating Gradient Synchrotron of Brookhaven National Laboratory, using a neutral beam stop, two analyzing dipoles, and redundant particle identification to remove backgrounds.

physics.ins-det

First Observation of the Rare Decay Mode K-long -> e+ e-

In an experiment designed to search for and study very rare two-body decay modes of the K-long, we have observed four examples of the decay K-long -> e+ e-, where the expected background is 0.17+-0.10 events. This observation translates into a branching fraction of 8.7^{+5.7}_{-4.1} X 10^{-12}, consistent with recent theoretical predictions. This result represents by far the smallest branching fraction yet measured in particle physics.

hep-ex

A Compact Beam Stop for a Rare Kaon Decay Experiment

We describe the development and testing of a novel beam stop for use in a rare kaon decay experiment at the Brookhaven AGS. The beam stop is located inside a dipole spectrometer magnet in close proximity to straw drift chambers and intercepts a high-intensity neutral hadron beam. The design process, involving both Monte Carlo simulations and beam tests of alternative beam-stop shielding arrangements, had the goal of minimizing the leakage of particles from the beam stop and the resulting hit rates in detectors, while preserving maximum acceptance for events of interest. The beam tests consisted of measurements of rates in drift chambers, scintilation counter hodoscopes, a gas threshold Cherenkov counter, and a lead glass array. Measurements were also made with a set of specialized detectors which were sensitive to low-energy neutrons, photons, and charged particles. Comparisons are made between these measurements and a detailed Monte Carlo simulation.

hep-ex