China

Xuewei Liu

Wei Dou

Japan

Benda Xu

Hanwen Wang

Guofu Cao

Erratum to: First-principle event reconstruction by time-charge readouts for TAO

This paper introduces a novel systematic construction of gapped domain walls (GDWs) within the Levin-Wen (LW) model. By gluing two LW models along their open sides in a compatible way, we achieve a complete GDW classification by subsets of bulk input data, which encompass the classifications in terms of bimodule categories. A generalized bimodule structure is introduced to capture domain-wall excitations. Furthermore, we demonstrate that folding along any GDW yields a gapped boundary (GB) described by a Frobenius algebra of the input UFC for the folded model, thus bridging our GDW classification and the GB classification in [1].

Yanyan Chen

Siyuan Wang

Yu Zhao

Yuting Hu

Yidun Wan

Classification of gapped domain walls of topological orders in 2+1 dimensions: a Levin-Wen model realization

The newly observed open-flavor tetraquark $$T_{c\bar{s}0}(2900)$$ has attracted many attentions, and searching for its spin partners is crucial to exploring the internal structure of those states. In this work, we will show that, the $$D_s^+\pi ^+$$ invariant mass distribution of the process $$B^+\rightarrow D^{*-}D_s^+\pi ^+$$ measured by LHCb has a resonant-like structure around 2830 MeV, which could be associated with the predicted $$T_{c\bar{s}2}$$ , the spin $$J=2$$ partner of $$T_{c\bar{s}0}(2900)$$ . Furthermore, we have evaluated the momenta of the angular mass distribution, which are very different for each of the spin assumptions, and have larger strength at the resonant energy than the peaks seen in the angular integrated mass distribution. We make a call for the experimental determination of these magnitudes, which could be used to pin down the existence of the $$T_{c\bar{s}2}$$ .

Wen-Tao Lyu

Li-Juan Liu

En Wang

Evidence of the open-flavor tetraquark $$T_{c\bar{s}2}$$ in the process $$B^+\rightarrow D^{*-}D_s^+\pi ^+$$

The Taishan Antineutrino Observatory (TAO) is a liquid-scintillator satellite experiment of the Jiangmen Underground Neutrino Observatory (JUNO) to measure the reference reactor neutrino spectrum with unprecedented energy resolution. We use inhomogeneous Poisson process and Tweedie generalized linear model (GLM) to characterize the detector response and the charge distribution of a SiPM. We develop a pure probabilistic model for time and charge of SiPMs from first principles to reconstruct point-like events in the TAO central detector. Thanks to our precise model and the high photo-coverage and quantum efficiency of the SiPM tiles at TAO, we achieve vertex position resolution better than $$20\,\hbox {mm}$$ , energy resolution of about $$2\%$$ at $$1\,\hbox {MeV}$$ and $$<0.5\%$$ non-uniformity, marking the world’s best performance of liquid scintillator detectors. With such resolution, we perceive $$\hbox {MeV}$$ events to exhibit track effects. It opens up an exciting possibility of computed tracking calorimeter for unsegmented liquid scintillator detector like TAO. Our methodology is applicable to other experiments that utilize PMTs for time and charge readouts.

First-principle event reconstruction by time-charge readouts for TAO

Since searches for the low-lying excited baryons <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Ξ</mi><mo stretchy="false">(</mo><mn>1</mn><mo>/</mo><msup><mn>2</mn><mo>−</mo></msup><mo stretchy="false">)</mo></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Σ</mi><mo stretchy="false">(</mo><mn>1</mn><mo>/</mo><msup><mn>2</mn><mo>−</mo></msup><mo stretchy="false">)</mo></math> are crucial to deepening our understanding of the light baryon spectrum, we have investigated the Cabibbo-favored process <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Ξ</mi><mi>c</mi><mo>+</mo></msubsup><mo stretchy="false">→</mo><mi mathvariant="normal">Λ</mi><msup><mover accent="true"><mi>K</mi><mo stretchy="false">¯</mo></mover><mn>0</mn></msup><msup><mi>π</mi><mo>+</mo></msup></math> by taking into account the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi></math>-wave pseudoscalar meson-octet baryon interactions within the chiral unitary approach, which could dynamically generate the resonances <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Ξ</mi><mo stretchy="false">(</mo><mn>1</mn><mo>/</mo><msup><mn>2</mn><mo>−</mo></msup><mo stretchy="false">)</mo></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Σ</mi><mo stretchy="false">(</mo><mn>1</mn><mo>/</mo><msup><mn>2</mn><mo>−</mo></msup><mo stretchy="false">)</mo></math>. The contributions from the excited kaons are double Cabibbo suppressed, and the contribution from the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Σ</mi><mo stretchy="false">(</mo><mn>1385</mn><mo stretchy="false">)</mo></math> is also suppressed due to Korner-Pati-Woo theory; thus, those states are expected to play negligible contributions in this process. We have predicted the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mover accent="true"><mi>K</mi><mo stretchy="false">¯</mo></mover><mn>0</mn></msup><mi mathvariant="normal">Λ</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>π</mi><mo>+</mo></msup><mi mathvariant="normal">Λ</mi></math> invariant mass distributions, which have the clear signals of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Ξ</mi><mo stretchy="false">(</mo><mn>1</mn><mo>/</mo><msup><mn>2</mn><mo>−</mo></msup><mo stretchy="false">)</mo></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Σ</mi><mo stretchy="false">(</mo><mn>1</mn><mo>/</mo><msup><mn>2</mn><mo>−</mo></msup><mo stretchy="false">)</mo></math>. Thus, the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Ξ</mi><mi>c</mi><mo>+</mo></msubsup><mo stretchy="false">→</mo><mi mathvariant="normal">Λ</mi><msup><mover accent="true"><mi>K</mi><mo stretchy="false">¯</mo></mover><mn>0</mn></msup><msup><mi>π</mi><mo>+</mo></msup></math> is an ideal process to search for the low-lying baryons <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Ξ</mi><mo stretchy="false">(</mo><mn>1</mn><mo>/</mo><msup><mn>2</mn><mo>−</mo></msup><mo stretchy="false">)</mo></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Σ</mi><mo stretchy="false">(</mo><mn>1</mn><mo>/</mo><msup><mn>2</mn><mo>−</mo></msup><mo stretchy="false">)</mo></math>, and we make a call for a precise measurements of this process in experiments, such as Belle II, LHCb, and the proposed Super Tau-Charm Facility.

Ying Li

Guan-Ying Wang

Longke Li

Wen-Cheng Yan

Study of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msubsup><mrow><mi mathvariant="normal">Ξ</mi></mrow><mrow><mi>c</mi></mrow><mrow><mo>+</mo></mrow></msubsup><mo stretchy="false">→</mo><mi mathvariant="normal">Λ</mi><msup><mrow><mover accent="true"><mrow><mi>K</mi></mrow><mrow><mo stretchy="false">¯</mo></mrow></mover></mrow><mrow><mn>0</mn></mrow></msup><msup><mrow><mi>π</mi></mrow><mrow><mo>+</mo></mrow></msup></mrow></math> and search for the low-lying baryons <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Ξ</mi><mo stretchy="false">(</mo><mn>1</mn><mo>/</mo><msup><mn>2</mn><mo>−</mo></msup><mo stretchy="false">)</mo></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Σ</mi><mo stretchy="false">(</mo><mn>1</mn><mo>/</mo><msup><mn>2</mn><mo>−</mo></msup><mo stretchy="false">)</mo></math>

We have investigated the process <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Λ</mi><mi>c</mi><mo>+</mo></msubsup><mo stretchy="false">→</mo><msup><mi>π</mi><mo>+</mo></msup><mi>η</mi><mi>n</mi></math> by taking into account the contributions from the nucleon resonance <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>N</mi><mo stretchy="false">(</mo><mn>1535</mn><mo stretchy="false">)</mo></math> and the scalar meson <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>a</mi><mn>0</mn></msub><mo stretchy="false">(</mo><mn>980</mn><mo stretchy="false">)</mo></math>, which could be dynamically generated by the interaction of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi></math>-wave pseudoscalar meson-octet baryon and the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi></math>-wave pseudoscalar meson-pseudoscalar meson, respectively. Our results show that, in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>η</mi><mi>n</mi></math> invariant mass distribution, there is a significant near-threshold enhancement structure, which could be associated with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>N</mi><mo stretchy="false">(</mo><mn>1535</mn><mo stretchy="false">)</mo></math>. On the other hand, one can find a clear cusp structure of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>a</mi><mn>0</mn></msub><mo stretchy="false">(</mo><mn>980</mn><mo stretchy="false">)</mo></math> in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>π</mi><mo>+</mo></msup><mi>η</mi></math> invariant mass distribution. We further estimate the ratio <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>R</mi><mo>=</mo><mi mathvariant="script">B</mi><mo stretchy="false">(</mo><msubsup><mrow><mi mathvariant="normal">Λ</mi></mrow><mrow><mi>c</mi></mrow><mrow><mo>+</mo></mrow></msubsup><mo stretchy="false">→</mo><msub><mrow><mi>a</mi></mrow><mrow><mn>0</mn></mrow></msub><mo stretchy="false">(</mo><mn>980</mn><msup><mrow><mo stretchy="false">)</mo></mrow><mrow><mo>+</mo></mrow></msup><mi>n</mi><mo stretchy="false">)</mo><mo>/</mo><mi mathvariant="script">B</mi><mo stretchy="false">(</mo><msubsup><mrow><mi mathvariant="normal">Λ</mi></mrow><mrow><mi>c</mi></mrow><mrow><mo>+</mo></mrow></msubsup><mo stretchy="false">→</mo><msup><mrow><mi>π</mi></mrow><mrow><mo>+</mo></mrow></msup><mi>η</mi><mi>n</mi><mo stretchy="false">)</mo><mo>≈</mo><mn>0.313</mn></mrow></math>. Our results can be tested by BESIII, Belle II, and the proposed Super Tau-Charm Facility experiments in the future.

Meng-Yuan Li

Roles of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>N</mi><mo stretchy="false">(</mo><mn>1535</mn><mo stretchy="false">)</mo></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>a</mi><mn>0</mn></msub><mo stretchy="false">(</mo><mn>980</mn><mo stretchy="false">)</mo></math> in the process <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msubsup><mrow><mi mathvariant="normal">Λ</mi></mrow><mrow><mi>c</mi></mrow><mrow><mo>+</mo></mrow></msubsup><mo stretchy="false">→</mo><msup><mrow><mi>π</mi></mrow><mrow><mo>+</mo></mrow></msup><mi>η</mi><mi>n</mi></mrow></math>

Recently, the LHCb Collaboration has measured the processes $$B^+\rightarrow D^-D_s^+\pi ^+$$ and $$B^+\rightarrow \bar{D}^0D_s^+\pi ^+$$ , where the $$D_s^+\pi ^-$$ and $$D_s^+\pi ^+$$ invariant mass distributions show the significant signals of two new open-flavored tetraquark states $$T_{c\bar{s}}(2900)^0$$ and $$T_{c\bar{s}}(2900)^{++}$$ , as the two of the isospin triplet. In this work, we have investigated the process $$\Lambda _b\rightarrow K^0D^0\Lambda $$ by taking into account the tetraquark state $$T_{c\bar{s}}(2900)^0$$ and the intermediate nucleon resonance $$N^*(1535)$$ , which could be dynamically generated by the interactions of the $$D^*K^*/D^*_s\rho $$ and the pseudoscalar meson-octet baryon, respectively. Our results show that a clear peak of the open-flavored tetraquark $$T_{c\bar{s}}(2900)$$ may appear in the $$K^0D^0$$ invariant mass distribution of the process $$\Lambda _b\rightarrow K^0D^0\Lambda $$ , which could be tested by future experiments.

Yun-He Lyu

Man-Yu Duan

Dian-Yong Chen

Theoretical study of the open-flavored tetraquark $$T_{c\bar{s}}(2900)$$ in the process $$\Lambda _b\rightarrow K^0D^0\Lambda $$

Recently, the LHCb Collaboration has measured two decay processes $$B^0\rightarrow \bar{D}^0D_s^+\pi ^-$$ and $$B^+\rightarrow D^-D_s^+\pi ^+$$ related to isospin symmetry, where two new open-flavored tetraquark states $$T_{c\bar{s}}(2900)^0$$ and $$T_{c\bar{s}}(2900)^{++}$$ that belong to an isospin triplet were observed in the $$D_s^+\pi ^-$$ and $$D_s^+\pi ^+$$ invariant mass distributions. In this work, we have investigated the validity of the process $$\bar{B}_s^0\rightarrow K^0D^0\pi ^0$$ as the promising process to confirm the existence of $$T_{c\bar{s}}(2900)^0$$ resonance. Taking into account the tetraquark state $$T_{c\bar{s}}(2900)$$ , as well as intermediate resonances $$K^*(892)$$ , $$K_0^*(1430)$$ , and $$K_2^*(1430)$$ , it has been shown that a clear peak of the open-flavored tetraquark $$T_{c\bar{s}}(2900)$$ appears in the $$K^0D^0$$ invariant mass distribution of the process $$\bar{B}_s^0\rightarrow K^0D^0\pi ^0$$ , which could be tested by future experiments.

Spain

Xiaoyu Wang

Theoretical study of the open-flavored tetraquark $$T_{c\bar{s}}(2900)$$ in the process $$\bar{B}_s^0 \rightarrow K^0 D^0 \pi ^0$$

We study from the theoretical point of view the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Λ</mi><mi>c</mi><mo>+</mo></msubsup><mo stretchy="false">→</mo><msup><mi>π</mi><mo>+</mo></msup><mi>η</mi><mi mathvariant="normal">Λ</mi></math> reaction, recently measured by the Belle and BESIII Collaborations, where clear signals are observed for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>a</mi><mn>0</mn></msub><mo stretchy="false">(</mo><mn>980</mn><mo stretchy="false">)</mo></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Λ</mi><mo stretchy="false">(</mo><mn>1670</mn><mo stretchy="false">)</mo></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Σ</mi><mo stretchy="false">(</mo><mn>1385</mn><mo stretchy="false">)</mo></math> excitation. By considering the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>a</mi><mn>0</mn></msub><mo stretchy="false">(</mo><mn>980</mn><mo stretchy="false">)</mo></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Λ</mi><mo stretchy="false">(</mo><mn>1670</mn><mo stretchy="false">)</mo></math> as dynamically generated resonances from the meson meson and meson baryon interaction, respectively, we are able to determine their relative production strengths in the reaction, which is also tied to the strength of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>π</mi><mo>+</mo></msup><mi>η</mi><mi mathvariant="normal">Λ</mi></math> tree level contribution. We observe that this latter strength is very big and there are large destructive interferences between the tree level and the rescattering terms where the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>a</mi><mn>0</mn></msub><mo stretchy="false">(</mo><mn>980</mn><mo stretchy="false">)</mo></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Λ</mi><mo stretchy="false">(</mo><mn>1670</mn><mo stretchy="false">)</mo></math> are generated. The <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Σ</mi><mo stretchy="false">(</mo><mn>1385</mn><mo stretchy="false">)</mo></math> contribution is included by means of a free parameter, the only one of the theory, up to a global normalization, when one considers only external emission, and we observe that the spin flip part of this term, usually ignored in theoretical and experimental works, plays an important role determining the shape of the mass distributions. Internal emission is also considered and it is found to play a minor role.

Chu-Wen Xiao

Ju-Jun Xie

Eulogio Oset

<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msubsup><mrow><mi mathvariant="normal">Λ</mi></mrow><mrow><mi>c</mi></mrow><mrow><mo>+</mo></mrow></msubsup><mo stretchy="false">→</mo><mi>η</mi><msup><mrow><mi>π</mi></mrow><mrow><mo>+</mo></mrow></msup><mi mathvariant="normal">Λ</mi></mrow></math> reaction and the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="normal">Λ</mi><msubsup><mrow><mi>a</mi></mrow><mrow><mn>0</mn></mrow><mrow><mo>+</mo></mrow></msubsup><mo stretchy="false">(</mo><mn>980</mn><mo stretchy="false">)</mo></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>π</mi></mrow><mrow><mo>+</mo></mrow></msup><mi mathvariant="normal">Λ</mi><mo stretchy="false">(</mo><mn>1670</mn><mo stretchy="false">)</mo></mrow></math> contributions

We study the $$B^+ \rightarrow D^{*-}D^+K^+$$ reaction, showing that a peak in the $$D^+K^+$$ mass distribution around $$2834 \text { MeV}$$ reported by LHCb could be associated with a theoretical exotic state with that mass, a width of $$19 \text { MeV}$$ and $$J^P=2^+$$ , stemming from the interaction of the $$D^{*+}K^{*+}$$ and $$D^{*+}_s \rho ^+$$ channels, which is a partner of the $$0^+$$ $$T_{c{\bar{s}}}(2900)$$ . We show that the data is compatible with this assumption, but also see that the mass distribution itself cannot discriminate between the spins $$J=0$$ , 1, 2 of the state. Then we evaluate the momenta of the angular mass distribution and show that they are very different for each of the spin assumptions, and that the momenta coming from interference terms have larger strength at the resonant energy than the peaks seen in the angular integrated mass distribution. We make a call for the experimental determination of these magnitudes, which has already been used by the LHCb in related decay reactions.

Possible signal of an exotic $$I=1$$ , $$J=2$$ state in the $$B \rightarrow D^{*-}D^+K^+$$ reaction