0000000000256271
AUTHOR
Sasa Prelovsek
Positive parity $D_s$ mesons
We study the positive parity charmed strange mesons using lattice QCD, the only reliable ab initio method to study QCD at low energies. Especially the experimentally observed $D_{s0}^*(2317)$ and $D_{s1}(2460)$ have challenged theory for quite some time. The dynamical lattice QCD simulations are performed at two distinct pion masses, $m_{\pi}$ = 266 MeV and 156 MeV, using both $\bar{c}s$ as well as $DK$ and $D^*K$ scattering operators in the construction of the correlation matrix in order to take into the account threshold effects. While the $J^P = 0^+$ channel benefited most from the inclusion of scattering operators, it was also crucial for the case of the $D_{s1}(2460)$. Using the L\"usc…
Substructure of Multiquark Hadrons (Snowmass 2021 White Paper)
In recent years there has been a rapidly growing body of experimental evidence for existence of exotic, multiquark hadrons, i.e. mesons which contain additional quarks, beyond the usual quark-antiquark pair and baryons which consist of more than three quarks. In all cases with robust evidence they contain at least one heavy quark Q=c or b, the majority including two heavy quarks. Two key theoretical questions have been triggered by these discoveries: (a) how are quarks organized inside these multiquark states -- as compact objects with all quarks within one confinement volume, interacting via color forces, perhaps with an important role played by diquarks, or as deuteron-like hadronic molec…
An analysis of the Lattice QCD spectra for $D^*_{s0}(2317)$ and $D^*_{s1}(2460)$
In this talk I present the results obtained using effective field theories in a finite volume from a reanalysis of lattice data on the $KD^{(*)}$ systems, where bound states of $KD$ and $KD^*$ are found and associated with the states $D^*_{s0}(2317)$ and $D^*_{s1}(2460)$, respectively. We confirm the presence of such states on the lattice data and determine the weight of the $KD$ channel in the wave function of $D^*_{s0}(2317)$ and that of $KD^*$ in the wave function of $D^*_{s1}(2460)$. Our results indicate a large meson-meson component in both cases.
Prediction of positive parity Bs mesons and search for the X(5568)
We use a combination of quark-antiquark and $B^{(*)}K$ interpolating fields to predict the mass of two QCD bound states below the $B^*K$ threshold in the quantum channels $J^P=0^+$ and $1^+$. The mesons correspond to the b-quark cousins of the $D_{s0}^*(2317)$ and $D_{s1}(2460)$ and have not yet been observed in experiment, even though they are expected to be found by LHCb. In addition to these predictions, we obtain excellent agreement of the remaining p-wave energy levels with the known $B_{s1}(5830)$ and $B_{s2}^*(5840)$ mesons. The results from our first principles calculation are compared to previous model-based estimates. More recently the D0 collaboration claimed the existence of an …
Identifying spin and parity of charmonia in flight with lattice QCD
The spectrum of charmonium resonances contains a number of unanticipated states along with several conventional quark-model excitations. The hadrons of different quantum numbers $J^P$ appear in a fairly narrow energy band, where $J^P$ refers to the spin-parity of a hadron at rest. This poses a challenge for Lattice QCD studies of (coupled-channel) meson-meson scattering aimed at the determination of scattering amplitudes and resonance pole positions. A wealth of information for this purpose can be obtained from the lattice spectra in frames with nonzero total momentum. These are particularly dense since hadrons with different $J^P$ contribute to any given lattice irreducible representation.…
Effective Field Theories in a Finite Volume
In this talk I present the formalism we have used to analyze Lattice data on two meson systems by means of effective field theories. In particular I present the results obtained from a reanalysis of the lattice data on the $KD^{(*)}$ systems, where the states $D^*_{s0}(2317)$ and $D^*_{s1}(2460)$ are found as bound states of $KD$ and $KD^*$, respectively. We confirm the presence of such states in the lattice data and determine the contribution of the $KD$ channel in the wave function of $D^*_{s0}(2317)$ and that of $KD^*$ in the wave function of $D^*_{s1}(2460)$. Our findings indicate a large meson-meson component in the two cases.
Charmonium resonances on the lattice
The nature of resonances and excited states near decay thresholds is encoded in scattering amplitudes, which can be extracted from single-particle and multiparticle correlators in finite volumes. Lattice calculations have only recently reached the precision required for a reliable study of such correlators. The distillation method represents a significant improvement insofar as it simplifies quark contractions and allows one to easily extend the operator basis used to construct interpolators. We present preliminary results on charmonium bound states and resonances on the Nf=2+1 CLS ensembles. The long term goal of our investigation is to understand the properties of the X resonances that do…
Prediction of positive parity $B_s$ mesons and search for the $X(5568)$
We use a combination of quark-antiquark and $B^{(*)}K$ interpolating fields to predict the mass of two QCD bound states below the $B^*K$ threshold in the quantum channels $J^P=0^+$ and $1^+$. The mesons correspond to the b-quark cousins of the $D_{s0}^*(2317)$ and $D_{s1}(2460)$ and have not yet been observed in experiment, even though they are expected to be found by LHCb. In addition to these predictions, we obtain excellent agreement of the remaining p-wave energy levels with the known $B_{s1}(5830)$ and $B_{s2}^*(5840)$ mesons. The results from our first principles calculation are compared to previous model-based estimates. More recently the D0 collaboration claimed the existence of an …
The Belle II Physics Book
cd. autorów: L. Cao48,‡, G. Caria145,‡, G. Casarosa57,‡, C. Cecchi56,‡,D. Cˇ ervenkov10,‡,M.-C. Chang22,‡, P. Chang92,‡, R. Cheaib146,‡, V. Chekelian83,‡, Y. Chen154,‡, B. G. Cheon28,‡, K. Chilikin77,‡, K. Cho70,‡, J. Choi14,‡, S.-K. Choi27,‡, S. Choudhury35,‡, D. Cinabro170,‡, L. M. Cremaldi146,‡, D. Cuesta47,‡, S. Cunliffe16,‡, N. Dash33,‡, E. de la Cruz Burelo9,‡, E. de Lucia52,‡, G. De Nardo54,‡, †Editor. ‡Belle II Collaborator. §Theory or external contributing author. M. De Nuccio16,‡, G. De Pietro59,‡, A. De Yta Hernandez9,‡, B. Deschamps129,‡, M. Destefanis60,‡, S. Dey116,‡, F.Di Capua54,‡, S.Di Carlo75,‡, J. Dingfelder129,‡, Z. Doležal10,‡, I. Domínguez Jiménez125,‡, T.V. Dong30,26,…
Charmonium resonances from 2+1 flavor CLS lattices
Many exotic charmonium resonances have been identified recently in experiment, however their nature and properties are mostly unknown. Algorithmic and theoretical progress in lattice calculations has enabled reliable numerical investigation of the spectrum below the strong decay threshold, while the study of charmonium resonances remains an open challenge. The main difficulty to overcome is the presence of many open decay channels which are coupled together, resulting in a complex finite volume quantization condition. We report on our recent progress towards the determination of single-channel and coupled-channel scattering matrices in the scalar and vector channels on CLS ensembles. We als…