The newly confirmed pentaquark state $$P_c(4312)$$ <math><mrow><msub><mi>P</mi><mi>c</mi></msub><mrow><mo>(</mo><mn>4312</mn><mo>)</mo></mrow></mrow></math>  has been treated as a weakly bound $$(\Sigma _c\bar{D})$$ <math><mrow><mo>(</mo><msub><mi>Σ</mi><mi>c</mi></msub><mover><mrow><mi>D</mi></mrow><mrow><mo>¯</mo></mrow></mover><mo>)</mo></mrow></math>  state by a well-established chiral constituent quark model and by a dynamical calculation on quark degrees of freedom where the quark exchange effect is accounted for. The obtained mass 4308 MeV agrees with data. In this work, the selected strong decays of the $$P_c(4312)$$ <math><mrow><msub><mi>P</mi><mi>c</mi></msub><mrow><mo>(</mo><mn>4312</mn><mo>)</mo></mrow></mrow></math>  state are studied with the obtained wave function. It is shown that the width of the $$\Lambda _c\bar{D}^*$$ <math><mrow><msub><mi>Λ</mi><mi>c</mi></msub><msup><mrow><mover><mrow><mi>D</mi></mrow><mrow><mo>¯</mo></mrow></mover></mrow><mo>∗</mo></msup></mrow></math>  decay is overwhelmed and the branching ratios of the $$p\,\eta _c$$ <math><mrow><mi>p</mi><mspace width="0.166667em"></mspace><msub><mi>η</mi><mi>c</mi></msub></mrow></math>  and $$p\,J/\psi $$ <math><mrow><mi>p</mi><mspace width="0.166667em"></mspace><mi>J</mi><mo>/</mo><mi>ψ</mi></mrow></math>  decays are both less than 1 percentage.

China

Yubing Dong

Pengnian Shen

Fei Huang

Zongye Zhang

Selected strong decays of pentaquark State $$P_c(4312)$$ <math><mrow><msub><mi>P</mi><mi>c</mi></msub><mrow><mo>(</mo><mn>4312</mn><mo>)</mo></mrow></mrow></math>  in a chiral constituent quark model

We present a systematic short time expansion for the generating function of the one point height probability distribution for the KPZ equation with droplet initial condition, which goes much beyond previous studies. The expansion is checked against a numerical evaluation of the known exact Fredholm determinant expression. We also obtain the next order term for the Brownian initial condition. Although initially devised for short time, a resummation of the series allows to obtain also the long time large deviation function, found to agree with previous works using completely different techniques. Unexpected similarities with stationary large deviations of TASEP with periodic and open boundaries are discussed. Two additional applications are given. (i) Our method is generalized to study the linear statistics of the Airy point process, i.e. of the GUE edge eigenvalues. We obtain the generating function of the cumulants of the empirical measure to a high order. The second cumulant is found to match the result in the bulk obtained from the Gaussian free field by Borodin and Ferrari [1,2], but we obtain systematic corrections to the Gaussian free field (higher cumulants, expansion towards the edge). This also extends a result of Basor and Widom [3] to a much higher order. We obtain large deviation functions for the Airy point process for a variety of linear statistics test functions. (ii) We obtain results for the counting statistics of trapped fermions at the edge of the Fermi gas in both the high and the low temperature limits.

France

Alexandre Krajenbrink

Pierre Le Doussal

Sylvain Prolhac

Systematic time expansion for the Kardar–Parisi–Zhang equation, linear statistics of the GUE at the edge and trapped fermions

In order to explore the possible physical quantities for judging different structures of the newly observed resonance <math><msup><mi>d</mi><mo>*</mo></msup><mo>(</mo><mn>2380</mn><mo>)</mo></math>, we study its electromagnetic form factors. In addition to the electric charge monopole <math><mi>C</mi><mn>0</mn></math>, we calculate its electric quadrupole <math><mi>E</mi><mn>2</mn></math>, magnetic dipole <math><mi>M</mi><mn>1</mn></math>, and magnetic octupole <math><mi>M</mi><mn>3</mn></math> form factors on the base of the realistic coupled <math><mrow><mi>Δ</mi><mi>Δ</mi><mo>+</mo><msub><mrow><mi>C</mi></mrow><mrow><mn>8</mn></mrow></msub><msub><mrow><mi>C</mi></mrow><mrow><mn>8</mn></mrow></msub></mrow></math> channel <math><msup><mi>d</mi><mo>*</mo></msup></math> wave function with both the <math><mi>S</mi></math>- and <math><mi>D</mi></math>-partial waves. The results show that the magnetic dipole moment and electric quadrupole deformation of <math><msup><mi>d</mi><mo>*</mo></msup></math> are 7.602 and <math><mrow><mn>2.53</mn><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>2</mn></mrow></msup><mtext> </mtext><mtext> </mtext><msup><mrow><mi>fm</mi></mrow><mrow><mn>2</mn></mrow></msup></mrow></math>, respectively. The calculated magnetic dipole moment in the naive constituent quark model is also compared with the result of <math><msub><mi>D</mi><mn>12</mn></msub><mi>π</mi></math> picture. By comparing with partial results where the <math><msup><mi>d</mi><mo>*</mo></msup></math> state is considered with a single <math><mi>Δ</mi><mi>Δ</mi></math> and with a <math><msub><mi>D</mi><mn>12</mn></msub><mi>π</mi></math> structures, we find that in addition to the charge distribution of <math><msup><mi>d</mi><mo>*</mo></msup></math>, the magnetic dipole moment and magnetic radius can be used to discriminate different structures of <math><msup><mi>d</mi><mo>*</mo></msup></math>. Moreover, a quite small electric quadrupole deformation indicates that <math><msup><mi>d</mi><mo>*</mo></msup></math> is more inclined to a slightly oblate shape due to our compact hexaquark dominated structure of <math><msup><mi>d</mi><mo>*</mo></msup></math>.

Form factors of the <math><msup><mi>d</mi><mo>*</mo></msup><mo>(</mo><mn>2380</mn><mo>)</mo></math> resonance

We improve the Monte-Carlo based QCD sum rules by introducing the rigorous Hölder-inequality-determined sum rule window and a Breit-Wigner type parametrization for the phenomenological spectral function. In this improved sum rule analysis methodology, the sum rule analysis window can be determined without any assumptions on OPE convergence or the QCD continuum. Therefore, an unbiased prediction can be obtained for the phenomenological parameters (the hadronic mass and width etc.). We test the new approach in the ρ meson channel with re-examination and inclusion of αs corrections to dimension-4 condensates in the OPE. We obtain results highly consistent with experimental values. We also discuss the possible extension of this method to some other channels.

Qi-Nan Wang

Canada

Zhu-Feng Zhang

T.G. Steele

Hong-Ying Jin

Zhuo-Ran Huang

A comprehensive revisit of the ρ meson with improved Monte-Carlo based QCD sum rulesSupported by NSFC (11175153, 11205093, 11347020), Open Foundation of the Most Important Subjects of Zhejiang Province, and K. C. Wong Magna Fund in Ningbo University, TGS is Supported by the Natural Sciences and Engineering Research Council of Canada (NSERC), Z. F. Zhang and Z. R. Huang are Grateful to the University of Saskatchewan for its Warm Hospitality

The width of three-body single-pion decay process dââNNÏ0,Â± is calculated by using the dâ wave function obtained from our chiral SU(3) constituent quark model calculation. The effect of the dynamical structure on the width of dâ is taken into account in both the single ÎÎ channel and coupled ÎÎ+CC two-channel approximations. Our numerical result shows that in the coupled-channel approximation, namely, the hidden-color configuration being considered, the obtained partial decay width of dââNNÏ is about several hundred keV, while in the single ÎÎ channel it is just about 2â¼3Â MeV . We, therefore, conclude that the partial width in the single-pion decay process of dâ is much smaller than the widths in its double-pion decay processes. Our prediction may provide a criterion for judging different interpretations of the dâ structure, as different pictures for the dâ may result quite different partial decay width.

Decay width of the d ⁎ (2380)→ NNπ process in a chiral constituent quark model

None Supervisory Editors of Nuclear Physics B

Editorial note on “Lepton-flavor violation and (g−2)μ in the μν SSM” by Hai-Bin Zhang, Tai-Fu Feng, Shu-Min Zhao and Tie-Jun Gao [Nucl. Phys. B 873 (2) (2013) 300–324]