Wed·Jul 17, 2024Wednesday·July 17, 2024

1. 01*

   A practical approach to calculating magnetic Johnson noise for precision measurements

   N. S. Phan🇺🇸 · S. M. Clayton🇺🇸 · Y. J. Kim🇰🇷 · T. M. Ito🇺🇸

   Magnetic Johnson noise is an important consideration for many applications involving precision magnetometry, and its significance will only increase in the future with improvements in measurement sensitivity. The fluctuation-dissipation theorem can be utilized to derive analytic expressions for magnetic Johnson noise in certain situations. But when used in conjunction with finite element analysis tools, the combined approach is particularly powerful as it provides a practical means to calculate the magnetic Johnson noise arising from conductors of arbitrary geometry and permeability. In this paper, we demonstrate this method to be one of the most comprehensive approaches presently available to calculate thermal magnetic noise. In particular, its applicability is shown to not be limited to cases where the noise is evaluated at a point in space but also can be expanded to include cases where the magnetic field detector has a more general shape, such as a finite size loop, a gradiometer, or a detector that consists of a polarized atomic species trapped in a volume. Furthermore, some physics insights gained through studies made using this method are discussed

   ↳ physics.app-phnucl-exphysics.atom-phphysics.bio-ph+1J.Appl.Phys.(2024)·1 citation
2. 02*

   New physical processes for extracting GPDs with a better sensitivity to partonic structure

   Jian-Wei Qiu🇺🇸 · Zhite Yu🇺🇸

   We introduce a new type of exclusive processes for a better study of generalized parton distributions (GPDs), which we refer to as single-diffractive hard exclusive processes (SDHEPs). We advocate a two-stage framework for picturing SDHEPs based on the separation of scales, which gives a clear description both kinematically and dynamically. We examine the sensitivity of the SDHEP to the parton momentum fraction $x$-dependence of GPDs, and demonstrate it quantitatively with two specific processes that can be readily measured at J-PARC or AMBER using a pion beam and at JLab using a photon beam, respectively. Both processes are capable of providing enhanced sensitivity to the $x$-dependence, overcoming the problem of shadow GPDs, and disentangling different types of GPDs with various spin asymmetries.

   ↳ hep-phhep-exhep-latnucl-ex+1PoS(2025)·0 citations
3. 03*

   Triply charm and bottom tetraquarks in a constituent quark model

   Gang Yang🇨🇳 · Jialun Ping🇨🇳 · Jorge Segovia🇪🇸

   Singly, doubly and fully charmed tetraquark candidates, \emph{e.g.}, $T_{c\bar{s}}(2900)$, $T_{cc}^{+}(3875)$ and $X(6900)$ have been recently reported by the LHCb collaboration. Therefore, it is timely to implement a theoretical investigation on triply heavy tetraquark systems; herein, the S-wave triply charm and bottom tetraquarks, $\bar{Q}Q\bar{q}Q$ $(q=u,d,s;Q=c,b)$, with spin-parity $J^P=0^{+}$, $1^{+}$ and $2^{+}$, isospin $I=0$ and $\frac{1}{2}$, are systematically studied in a constituent quark model. Besides, all tetraquark configurations, \emph{i.e.} meson-meson, diquark-antidiquark and K-type arrangements, along with any allowed color structure, are comprehensively considered. The Gaussian expansion method (GEM), in combination with the complex-scaling method (CSM), which is quite ingenious in dealing with either bound or resonances, is the approach adopted in solving the complex scaled Schrödinger equation. This theoretical framework has already been applied in various tetra- and penta-quark systems. In a fully coupled-channel calculation within the GEM$+$CSM, narrow resonances are found in each $I(J^P)$ channel of the charm and bottom sector. In particular, triply charm and bottom tetraquark resonances are obtained in $5.6-5.9$ GeV and $15.3-15.7$ GeV, respectively. We provide also some insights of the compositeness of these exotic states, such as the inner quark distance, magnetic moment and dominant wave function component. All this may help to distinguish them in future high energy nuclear and particle experiments.

   ↳ hep-phhep-exhep-latnucl-ex+1PRD(2024)·10 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.