Mini-workshop on “$T_{cc}^+$ and beyond”, Online

Tuesday 14 Sept 2021, 12:00 → 19:00 Europe/Zurich

Giovanni Cavallero (CERN), Liupan An (CERN), Vanya Belyaev (NRC "Kurchatov Institute" (ITEP) (RU))

The workshop is dedicated to discussion on the recent observation of the exotic doubly charmed tetraquark $T_{cc}^+$.   The main purpose of the workshop is to summarize our current knowledge, both experimental and theoretical, on double heavy tetraquark system, including the properties of the $T_{cc}^+$ tetraquark and  discuss the next steps. 

1. LHCb-PAPER-2021-031, arXiv:2109.01038
2. LHCb-PAPER-2021-032, arXiv:2109.01056

The workshop is scheduled at the same date after the CERN LHC seminar, where the observation of the $T_{cc}^+$  tetraquark and measurement of its properties  is reported.  

Due to COVID-19, workshop is purely virtual, on-line only

ZOOM Meeting ID: 62186302872

ZOOM Password: 90385253

ZOOM link

 

Recording

1 Welcome

2 $T_{cc}^+$: now + next steps

Speaker: Vanya Belyaev (NRC "Kurchatov Institute" (ITEP) (RU))

20210914-Tcc-Tcc.pdf

3 Beyond $T_{cc}^+$ : $T_{bb}$, $T_{bc}$, ...

Speaker: Steven R. Blusk (Syracuse University (US))

Beyond_Tcc.pdf

4 What can we learn from the width of the $T_{cc}^+$ tetraquark?

The width of the $T_{cc}^+$ tetraquark (dimeson) is expected to differ considerably from the widths of its constituent $D^{*0}$ and $D^{*+}$. Unfortunately, reliable values of the $D^{*0}$ and $T_{cc}^+$ widths are not yet known and at least theoretical estimates would be welcome. An interesting effect is due to the charge splitting of the
$(D^{*+})D^0$ and $(D^{*0})D^+$ thresholds,
therefore $T_{cc}^+$ will not have a pure isospin coupling
$T_{cc}^+ = [(D^{*+})D^0 - (D^{*0})D^+]/\sqrt{2}$ and the actual composition may be seen in branching ratios. The width of $T_{cc}^+$ may depend strongly on threshold effects since its energy is not discrete and its peak extends beyond the lowest threshold, making it partially unstable and therefore broader. I shal try to estimate some of these effects.

Speaker: Mitja Rosina

Tcc_talk6.ppt

5 $T_{cc}^+$ and its cousins

Speaker: Marek Karliner

karliner_Tcc_Sep_14_2021.pdf

6 Triangle singularities in the production of $T_{cc}^+$ and a soft pion

Speaker: Eric Braaten

TriangleTcc+.pdf

15:20 Coffee/tea break

7 Generality of near-threshold structures and a survey of hidden-charm and double-charm hadronic molecules

Speaker: Feng-Kun Guo (Insitute of Theoretical Physics, Chinese Academy of Sciences)

TccWorkshop_FKGuo.pdf

8 Heavy tetraquark states from Lattice QCD

Speaker: Nilmani Mathur

fourquark_n_mathur.pdf

9 $T_{cc}$ and its heavier cousins: Structure and binding in lattice QCD

Speakers: Anthony Sebastian Francis (Universitaet Bern (CH)), Randy Lewis (York University)

Tcc-LHCb-miniworkshop-afrancis-rlewis.pdf

10 Some reflections on tetraquarks and molecules

Speakers: Antonio Polosa (Sapienza Universita e INFN, Roma I (IT)), Antonio Polosa (Universita' La Sapienza, Roma - Italy)

LHCb21.pdf

11 Stability of the double-heavy tetraquark: lessons from atomic physics

Speakers: Jean-Marc Rene Richard (Centre National de la Recherche Scientifique (FR)), jean-marc Richard (IPNL)

CERN-LHCb-2021.pdf

12 Closing remarks

Speaker: Marco Pappagallo (Universita e INFN, Bari (IT))

Tcc_Closing_Remarks.pdf