arXiv subjects

Pedro Brandão

Publications and source records attributed to Pedro Brandão.

7 recordsLinked to original sources

arXiv2026

A pion-driven near-threshold enhancement in the $π\,T_{cc}$ system

Hadronic molecules are commonly viewed as products of near-threshold two-body dynamics. We investigate whether an experimentally established molecule can also serve as a building block for a more complex exotic hadron by studying pion scattering off $T^+_{cc}(3875)$. Treating $T_{cc}$ as a correlated isoscalar $D D^*$ molecular cluster, we describe the resulting $πD D^*$ dynamics in the $I(J^P)=1(1^-)$ channel within the Fixed Center Approximation to the Faddeev equations. The full three-body amplitude develops a pronounced enhancement slightly above the $πT_{cc}$ threshold, centered at $M_{\rm peak}\simeq 4055$~MeV, with an apparent width of approximately $60$~MeV. The associated behavior of the real and imaginary parts of the amplitude is compatible with a resonant-like interpretation. These results show that the lightest hadron can play an active dynamical role in promoting an observed hadronic molecule into a building block of a heavier near-threshold structure generated by the three-body dynamics. We propose searching for this enhancement in the $T_{cc}π$ invariant-mass distribution, particularly through the $D^0D^0π^+π^-$ final state.

hep-ph↗

arXiv2026

Exotic states with charm and/or strangeness

In this talk, I will discuss the properties of several exotic states with charm and/or strangeness. These states can be interpreted either as being generated from two- or three-hadron dynamics. In particular, I will focus on $D_1(2420)$ and some predictions of three-body states obtained from $n\bar

hep-ph↗

arXiv2026

Probing the $G(3900)$ State in Heavy-Ion Collisions

We investigate the interactions of the recently confirmed exotic hadron $G(3900)$ with the hadronic medium composed of light mesons produced in heavy-ion collisions. Using an effective Lagrangian approach, we compute both vacuum and thermally averaged cross sections for processes such as $G(3900) + π\to D^{(\ast)} + \bar{D}^{(\ast)}$ and their inverse reactions. Following recent proposals, the $G(3900)$ is interpreted as a $P$-wave $D\bar{D}^*/D^*\bar{D}$ molecular state. The resulting thermally averaged cross sections are employed in a rate equation to determine the time evolution of the $G(3900)$ multiplicity, with initial conditions provided by statistical and coalescence hadronization models. We compute the number of $G(3900)$'s produced in central Pb-Pb collisions at $\sqrt{s_{NN}} = 5.02$ TeV and compare it with the number of produced $Z_c(3900)$'s . We obtain a considerably smaller final yield of $G(3900)$ compared to $Z_c(3900)$.

hep-ph↗

arXiv2026

Searching for the pseudoscalar partner of $G(3900)$ via radiative $Y(4230)$ decays

Inspired by the $P$-wave molecular interpretation of the recently observed vector state $G(3900)$, we analyze the production of its possible pseudoscalar partner, denoted here as $G_0(3900)$, via the radiative decay $Y(4230) \to γG_0(3900)$. The $G_0(3900)$ is interpreted as a $P$-wave molecular state with quantum numbers $J^{PC}=0^{-+}$, dominated by the $D\bar{D}^{\ast}/\bar{D}D^{\ast}$ components. Although not yet experimentally established, such a structure is expected to appear near the $D\bar{D}^*$ threshold and to exhibit characteristic production patterns. The decay is assumed to proceed through a triangle mechanism. Depending on the model parameters and the binding energy of $G_0(3900)$, the resulting branching fraction lies in the range $\mathcal{B}(Y(4230) \to γG_0(3900)) = 3.8 \times 10^{-5} - 3.3 \times 10^{-4}$. Our results offer a pathway to search for signatures of $G_0(3900)$ in radiative channels and also provide a test of the consistency of loop-mediated radiative decays with a molecular description of the $Y(4230)$.

hep-ph↗

arXiv2026

$D^*π$ interaction from the lineshape of $D_1(2420)$ in $B$-decays

We present a model calculation to reproduce the differential mass distribution for the $D^*π$ system in the reactions $B^- \to D^{*+} π^- π^-$ and $B^{+}\to D_s^+D^{*-}π^{+}$ analyzed by the LHCb Collaboration, which shows a dominant signal for $D_1(2420)$. %\textbf{We} (The idea is to) We consider a model based on coupled channel meson-meson interactions that can describe the properties of $D_1(2420)$ in terms of the underlying dynamics, use it to determine the invariant mass distribution of the $D^*π$ system, and compare the results with the experimental data. We also determine the $D^*π$ scattering length, for which different values are available from different sources, leading to a controversy. To our knowledge, this is the first attempt to reproduce the mentioned data using model calculations. Our formalism relies on the hadronization of different mesons through a weak decay, allowing for the final-state (strong) interactions among the relevant constituents. We benefit from our previous work when obtaining the amplitudes corresponding to the strong interactions. We hope that our findings can be useful in further investigations of the properties of $D_1(2420)$.

hep-ph↗

arXiv2025

Correlation functions for $n\,\bar{D}_{s1}(2460)$ and $n\,\bar{D}_{s1}(2536)$

We study the interaction of the $n \bar {D}_{s1}(2460)$ and $n \bar {D}_{s1}(2536)$ systems from the perspective that the $D_{s1}(2460)$ and $D_{s1}(2536)$ states are molecular states of $K D^*$ and $K^*D$, respectively. We use an improved version of the fixed center approximation to the Faddeev equations which fulfills exact elastic unitarity at the threshold of the systems. We predict the existence of resonant states below threshold and also determine the scattering length, effective range and correlation functions of these systems, showing that the results contain important information to test the assumed molecular nature of the two $D_{s1}$ states.

hep-ph↗

arXiv2017

Experimentation with MANETs of Smartphones

Mobile AdHoc NETworks (MANETs) have been identified as a key emerging technology for scenarios in which IEEE 802.11 or cellular communications are either infeasible, inefficient, or cost-ineffective. Smartphones are the most adequate network nodes in many of these scenarios, but it is not straightforward to build a network with them. We extensively survey existing possibilities to build applications on top of ad-hoc smartphone networks for experimentation purposes, and introduce a taxonomy to classify them. We present AdHocDroid, an Android package that creates an IP-level MANET of (rooted) Android smartphones, and make it publicly available to the community. AdHocDroid supports standard TCP/IP applications, providing real smartphone IEEE 802.11 MANET and the capability to easily change the routing protocol. We tested our framework on several smartphones and a laptop. We validate the MANET running off-the-shelf applications, and reporting on experimental performance evaluation, including network metrics and battery discharge rate.

cs.NI↗