nucl-th digest · May 5, 2021

X (3872)

-like peak in

B \to (J / ψ π^{+} π^{-}) K π

due to triangle singularity

Triangle mechanisms for

B^{0} \to (J / ψ π^{+} π^{-}) K^{+} π^{-}

are studied. Experimentally, an

X (3872)

peak has been observed in this process. When the final

(J / ψ π^{+} π^{-}) π

invariant mass is around the

D^{*} D ˉ^{*}

threshold, one of the triangle mechanisms causes a triangle singularity and generates a sharp

X (3872)

-like peak in the

J / ψ π^{+} π^{-}

invariant mass distribution. The Breit-Wigner mass and width fitted to the spectrum are 3871.68 MeV (a few keV above the

D^{* 0} D ˉ^{0}

threshold) and

\sim

0.4 MeV, respectively.These Breit-Wigner parameters hardly depends on a choice of the model parameters. Comparing with the precisely measured

X (3872)

mass and width,

3871.69 \pm 0.17

MeV and

< 1.2

MeV, the agreement is remarkable. When studying the

X (3872)

signal from this process, this non-resonant contribution has to be understood in advance. We also study a charge analogous process

B^{0} \to (J / ψ π^{0} π^{-}) K^{+} π^{0}

. A similar triangle singularity exists and generates an

X^{-} (3876)

-like peak.

↳ hep-phhep-exnucl-thFew Body Syst.(2021)·0 citations

Crystals of gauged solitons, force free plasma and resurgence

Gonzalo Barriga🇨🇱 · Fabrizio Canfora🇨🇱 · Matías Torres🇨🇱 · Aldo Vera🇨🇱

We show that the (3+1)-dimensional gauged non-linear sigma model minimally coupled to a U(1) gauge field possesses analytic solutions representing gauged solitons at finite Baryon density whose electromagnetic field is a Force Free Plasma. These gauged solitons manifest a crystalline structure and generate in a very natural way persistent currents able to support Force Free Plasma electromagnetic fields. The trajectories of charged test particles moving within these configurations can be characterized. Quite surprisingly, despite the non-integrable nature of the theory, some of the perturbations of these gauged solitons allow to identify a proper resurgent parameter. In particular, the perturbations of the solitons profile are related to the Lamé operator. On the other hand, the electromagnetic perturbations on the configurations satisfy a two-dimensional effective Schrodinger equation, where the soliton background interacts with the electromagnetic perturbations through an effective two-dimensional periodic potential. We studied numerically the band energy spectrum for different values of the free parameters of the theory and we found that bands-gaps are modulated by the potential strength. Finally we compare our crystal solutions with those of the (1+1)- dimesional Gross-Neveu model.

↳ hep-thastro-ph.HEhep-phnucl-thPRD(2021)·10 citations

Wednesday·May 5, 2021

An $X (3872)$ -like peak in $B \to (J / ψ π^{+} π^{-}) K π$ due to triangle singularity

Crystals of gauged solitons, force free plasma and resurgence

Affiliations

An X(3872)-like peak in B→(J/ψπ+π−)Kπ due to triangle singularity

Crystals of gauged solitons, force free plasma and resurgence

Affiliations

An $X (3872)$ -like peak in $B \to (J / ψ π^{+} π^{-}) K π$ due to triangle singularity