We perform a detailed analysis of the semileptonic <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Ξ</mi><mi>b</mi></msub><mo stretchy="false">→</mo><msub><mi mathvariant="normal">Ξ</mi><mi>c</mi></msub><msup><mo>ℓ</mo><mo>−</mo></msup><msub><mover accent="true"><mi>ν</mi><mo stretchy="false">¯</mo></mover><mo>ℓ</mo></msub></math> decays within the perturbative QCD framework. In our study, the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Ξ</mi><mi>b</mi></msub><mo stretchy="false">→</mo><msub><mi mathvariant="normal">Ξ</mi><mi>c</mi></msub></math> transition form factors are calculated using several popular models for baryonic light-cone distribution amplitudes. These form factors are then employed to analyze a range of observable quantities for the semileptonic processes via the helicity formalism. Our work presents predictions for the branching fractions of these decays for both the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>τ</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>e</mi></math> channels. Notably, the obtained lepton flavor universality ratio, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="script">R</mi><msub><mi mathvariant="normal">Ξ</mi><mi>c</mi></msub></msub><mo>≈</mo><mn>0.3</mn></math>, may offer new insights into the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi mathvariant="script">R</mi><mrow><mo stretchy="false">(</mo><mo>*</mo><mo stretchy="false">)</mo></mrow></msup></math> puzzle. Furthermore, we investigate various angular observables, such as forward-backward asymmetries, lepton-side convexity parameters, and polarization asymmetries, which provide complementary information regarding potential new physics in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>b</mi></math>-baryonic semileptonic transitions. The numerical results for these angular observables are presented as both functions of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>q</mi><mn>2</mn></msup></math> and as averaged values. We observe that the lepton mass plays a significant role in shaping the angular distributions, affecting most of the observables under consideration. These results are expected to be valuable for both current and future experimental investigations of semileptonic heavy-to-heavy baryon decays.

China

Zhou Rui

Zhi-Tian Zou

Ya Li

Ying Li

Semileptonic baryon decays <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Ξ</mi><mi>b</mi></msub><mo stretchy="false">→</mo><msub><mi mathvariant="normal">Ξ</mi><mi>c</mi></msub><msup><mo>ℓ</mo><mo>−</mo></msup><msub><mover accent="true"><mi>ν</mi><mo stretchy="false">¯</mo></mover><mo>ℓ</mo></msub></math> in perturbative QCD

Using <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>e</mi><mo>+</mo></msup><msup><mi>e</mi><mo>−</mo></msup></math> collision data corresponding to an integrated luminosity of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>10.6</mn><mtext> </mtext><mtext> </mtext><msup><mi>fb</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math> collected at center-of-mass energies between 4.258 and 4.681 GeV with the BESIII detector at the BEPCII collider, we search for the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mn>1</mn><mrow><mo>−</mo><mo>+</mo></mrow></msup></math> charmoniumlike hybrid via <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>e</mi><mo>+</mo></msup><msup><mi>e</mi><mo>−</mo></msup><mo stretchy="false">→</mo><mi>γ</mi><mi>η</mi><msub><mi>η</mi><mi>c</mi></msub></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>e</mi><mo>+</mo></msup><msup><mi>e</mi><mo>−</mo></msup><mo stretchy="false">→</mo><mi>γ</mi><msup><mi>η</mi><mo>′</mo></msup><msub><mi>η</mi><mi>c</mi></msub></math> decays for the first time. No significant signal is observed, and the upper limits on the Born cross sections for both processes are set at the 90% confidence level.

M. Ablikim

Russia

M.N. Achasov

Sweden

P. Adlarson

X.C. Ai

Germany

R. Aliberti

Italy

A. Amoroso

Q. An

Y. Bai

JINR

O. Bakina

Y. Ban

H.R. Bao

Poland

V. Batozskaya

Mongolia

K. Begzsuren

N. Berger

M. Berlowski

M. Bertani

D. Bettoni

F. Bianchi

E. Bianco

A. Bortone

I. Boyko

United States

R.A. Briere

A. Brueggemann

H. Cai

M.H. Cai

X. Cai

A. Calcaterra

G.F. Cao

N. Cao

Türkiye

S.A. Cetin

X.Y. Chai

J.F. Chang

G.R. Che

Y.Z. Che

C.H. Chen

Chao Chen

G. Chen

H.S. Chen

H.Y. Chen

M.L. Chen

S.J. Chen

S.L. Chen

S.M. Chen

T. Chen

X.R. Chen

X.T. Chen

X.Y. Chen

Y.B. Chen

Y.Q. Chen

Z.J. Chen

Z.K. Chen

South Korea

S.K. Choi

X. Chu

G. Cibinetto

F. Cossio

United Kingdom

J. Cottee-Meldrum

J.J. Cui

H.L. Dai

J.P. Dai

A. Dbeyssi

R.E. de Boer

D. Dedovich

C.Q. Deng

Z.Y. Deng

A. Denig

I. Denysenko

M. Destefanis

F. De Mori

B. Ding

X.X. Ding

Y. Ding

Y.X. Ding

J. Dong

L.Y. Dong

M.Y. Dong

X. Dong

M.C. Du

S.X. Du

Y.Y. Duan

P. Egorov

G.F. Fan

J.J. Fan

Y.H. Fan

J. Fang

S.S. Fang

W.X. Fang

Y.Q. Fang

R. Farinelli

L. Fava

F. Feldbauer

G. Felici

C.Q. Feng

J.H. Feng

L. Feng

Q.X. Feng

Y.T. Feng

Search for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mn>1</mn><mrow><mo>−</mo><mo>+</mo></mrow></msup></math> charmoniumlike hybrid via <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>e</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>e</mi></mrow><mrow><mo>−</mo></mrow></msup><mo stretchy="false">→</mo><mi>γ</mi><msup><mrow><mi>η</mi></mrow><mrow><mo stretchy="false">(</mo><mo>′</mo><mo stretchy="false">)</mo></mrow></msup><msub><mrow><mi>η</mi></mrow><mrow><mi>c</mi></mrow></msub></mrow></math> at center-of-mass energies between 4.258 and 4.681 GeV

Using <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>ψ</mi><mo stretchy="false">(</mo><mn>3686</mn><mo stretchy="false">)</mo><mo stretchy="false">→</mo><msup><mrow><mi>π</mi></mrow><mrow><mn>0</mn></mrow></msup><msub><mrow><mi>h</mi></mrow><mrow><mi>c</mi></mrow></msub></mrow></math> decays from a data sample of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mo stretchy="false">(</mo><mn>27.12</mn><mo>±</mo><mn>0.14</mn><mo stretchy="false">)</mo><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mn>8</mn></mrow></msup><mtext> </mtext><mtext> </mtext><mi>ψ</mi><mo stretchy="false">(</mo><mn>3686</mn><mo stretchy="false">)</mo></mrow></math> events collected by the BESIII detector at the BEPCII collider, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>h</mi><mi>c</mi></msub></math> radiative decays to multiple light hadrons below <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>2.8</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi><mo>/</mo><msup><mi>c</mi><mn>2</mn></msup></math>—<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>γ</mi><msup><mi>π</mi><mo>+</mo></msup><msup><mi>π</mi><mo>−</mo></msup></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>γ</mi><msup><mi>π</mi><mo>+</mo></msup><msup><mi>π</mi><mo>−</mo></msup><mi>η</mi></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>γ</mi><mn>2</mn><mo stretchy="false">(</mo><msup><mi>π</mi><mo>+</mo></msup><msup><mi>π</mi><mo>−</mo></msup><mo stretchy="false">)</mo></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>γ</mi><mi>p</mi><mover accent="true"><mi>p</mi><mo stretchy="false">¯</mo></mover></math>—are observed for the first time, each with a significance greater than <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>5</mn><mi>σ</mi></math>. The corresponding branching fractions are measured. Furthermore, intermediate states are investigated, leading to the first observation of the decay process of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>h</mi></mrow><mrow><mi>c</mi></mrow></msub><mo stretchy="false">→</mo><mi>γ</mi><msub><mrow><mi>f</mi></mrow><mrow><mn>2</mn></mrow></msub><mo stretchy="false">(</mo><mn>1270</mn><mo stretchy="false">)</mo><mo stretchy="false">→</mo><mi>γ</mi><msup><mrow><mi>π</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>π</mi></mrow><mrow><mo>−</mo></mrow></msup></mrow></math> with a significance of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>5.1</mn><mi>σ</mi></math>. This observation represents the first instance of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>h</mi><mi>c</mi></msub></math> radiative decay to a tensor state.

G. Chelkov

C. Chen

Z.H. Duan

M. Fritsch

C.D. Fu

J.L. Fu

Y.W. Fu

Observation of Charmonium <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>h</mi></mrow><mrow><mi>c</mi></mrow></msub></mrow></math> Radiative Decays to Multiple Light Hadrons and the Tensor State <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>f</mi></mrow><mrow><mn>2</mn></mrow></msub><mo stretchy="false">(</mo><mn>1270</mn><mo stretchy="false">)</mo></mrow></math>

In the present work, we propose to investigate the productions of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Λ</mi><mi>c</mi></msub><mo stretchy="false">(</mo><mn>2910</mn><mo stretchy="false">)</mo></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Λ</mi><mi>c</mi></msub><mo stretchy="false">(</mo><mn>2940</mn><mo stretchy="false">)</mo></math> in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>π</mi><mo>−</mo></msup><mi>p</mi><mo stretchy="false">→</mo><msup><mi>D</mi><mo>−</mo></msup><msup><mi>D</mi><mn>0</mn></msup><mi>p</mi></math> processes by utilizing an effective Lagrangian approach, where <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Λ</mi><mi>c</mi></msub><mo stretchy="false">(</mo><mn>2910</mn><mo stretchy="false">)</mo></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Λ</mi><mi>c</mi></msub><mo stretchy="false">(</mo><mn>2940</mn><mo stretchy="false">)</mo></math> are considered as <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>D</mi><mo>*</mo></msup><mi>N</mi></math> molecular states with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>J</mi><mi>P</mi></msup></math> quantum numbers to be <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>1</mn><mo>/</mo><msup><mn>2</mn><mo>−</mo></msup></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>3</mn><mo>/</mo><msup><mn>2</mn><mo>−</mo></msup></math>, respectively. With the cutoff parameter determined by the upper limit of the cross sections for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>π</mi><mo>−</mo></msup><mi>p</mi><mo stretchy="false">→</mo><msup><mi>D</mi><mrow><mo>*</mo><mo>−</mo></mrow></msup><msub><mi mathvariant="normal">Λ</mi><mi>c</mi></msub><mo stretchy="false">(</mo><mn>2286</mn><mo stretchy="false">)</mo></math>, the ratios of the cross sections for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>π</mi><mo>−</mo></msup><mi>p</mi><mo stretchy="false">→</mo><msup><mi>D</mi><mrow><mo>*</mo><mo>−</mo></mrow></msup><msub><mi mathvariant="normal">Λ</mi><mi>c</mi></msub><mo stretchy="false">(</mo><mn>2286</mn><mo stretchy="false">)</mo></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>π</mi><mo>−</mo></msup><mi>p</mi><mo stretchy="false">→</mo><msup><mi>D</mi><mo>−</mo></msup><msub><mi mathvariant="normal">Λ</mi><mi>c</mi></msub><mo stretchy="false">(</mo><mn>2286</mn><mo stretchy="false">)</mo></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>π</mi><mo>−</mo></msup><mi>p</mi><mo stretchy="false">→</mo><msup><mi>D</mi><mo>−</mo></msup><msub><mi mathvariant="normal">Λ</mi><mi>c</mi></msub><mo stretchy="false">(</mo><mn>2910</mn><mo stretchy="false">)</mo></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>π</mi><mo>−</mo></msup><mi>p</mi><mo stretchy="false">→</mo><msup><mi>D</mi><mo>−</mo></msup><msub><mi mathvariant="normal">Λ</mi><mi>c</mi></msub><mo stretchy="false">(</mo><mn>2940</mn><mo stretchy="false">)</mo></math> are estimated to be <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>1</mn><mo>:</mo><mn>4.8</mn><mo>:</mo><mn>1.42</mn><mo>:</mo><mn>0.26</mn></math> at <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>p</mi><mi>π</mi></msub><mo>=</mo><mn>30</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math>. Considering that the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Λ</mi><mi>c</mi></msub><mo stretchy="false">(</mo><mn>2910</mn><mo stretchy="false">)</mo></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Λ</mi><mi>c</mi></msub><mo stretchy="false">(</mo><mn>2940</mn><mo stretchy="false">)</mo></math> state can further decay into <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>D</mi><mn>0</mn></msup><mi>p</mi></math>, we estimate the cross sections for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>π</mi><mo>−</mo></msup><mi>p</mi><mo stretchy="false">→</mo><msup><mi>D</mi><mo>−</mo></msup><msup><mi>D</mi><mn>0</mn></msup><mi>p</mi></math> process and the differential cross sections depending on the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>D</mi><mn>0</mn></msup><mi>p</mi></math> invariant mass spectrum. Our estimations indicate that the total cross sections are <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">(</mo><mn>0.4</mn><msubsup><mn>9</mn><mrow><mo>−</mo><mn>0.38</mn></mrow><mrow><mo>+</mo><mn>1.56</mn></mrow></msubsup><mo stretchy="false">)</mo><mtext> </mtext><mtext> </mtext><mi>nb</mi></math> when <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>p</mi><mi>π</mi></msub><mo>=</mo><mn>15</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math>, where the uncertainties result from the variation of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Λ</mi><mi>r</mi></msub></math>. By comparing the contributions of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>s</mi></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>u</mi></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>t</mi></math>-channels, we conclude that the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>t</mi></math>-channel plays the predominant role. Moreover, the present estimations suggest that the structure around 2.9 GeV in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>D</mi><mn>0</mn></msup><mi>p</mi></math> invariant mass spectrum of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>π</mi><mo>−</mo></msup><mi>p</mi><mo stretchy="false">→</mo><msup><mi>D</mi><mo>−</mo></msup><msup><mi>D</mi><mn>0</mn></msup><mi>p</mi></math> process should correspond to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Λ</mi><mi>c</mi></msub><mo stretchy="false">(</mo><mn>2910</mn><mo stretchy="false">)</mo></math> rather than <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Λ</mi><mi>c</mi></msub><mo stretchy="false">(</mo><mn>2940</mn><mo stretchy="false">)</mo></math>, which can be tested by further experimental measurements at J-PARC in the future.

Quan-Yun Guo

Dian-Yong Chen

<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Λ</mi><mi>c</mi></msub><mo stretchy="false">(</mo><mn>2910</mn><mo stretchy="false">)</mo></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Λ</mi><mi>c</mi></msub><mo stretchy="false">(</mo><mn>2940</mn><mo stretchy="false">)</mo></math> productions in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>π</mi><mo>−</mo></msup><mi>p</mi></math> scattering process

In this paper, we investigate the semileptonic decays <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>B</mi><mi>c</mi></msub><mo stretchy="false">→</mo><msub><mi>η</mi><mi>c</mi></msub><mo>ℓ</mo><msub><mover accent="true"><mi>ν</mi><mo stretchy="false">¯</mo></mover><mo>ℓ</mo></msub></math> using the quantum chromodynamics (QCD) sum rules within the framework of Standard Model (SM). We further explore the potential to probe signatures of new physics (NP) beyond the SM through these decays. First, we derive the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>ξ</mi></math>-moments <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">⟨</mo><msubsup><mi>ξ</mi><mrow><mn>2</mn><mo>;</mo><msub><mi>η</mi><mi>c</mi></msub></mrow><mi>n</mi></msubsup><mo stretchy="false">⟩</mo></math> of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>η</mi><mi>c</mi></msub></math>-meson leading-twist distribution amplitude <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>ϕ</mi><mrow><mn>2</mn><mo>;</mo><msub><mi>η</mi><mi>c</mi></msub></mrow></msub></math> using the QCD sum rules within the background field theory. Considering contributions from the vacuum condensates up to dimension-six, the first two nonzero <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>ξ</mi></math>-moments at the scale of 4 GeV are found to be <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mo stretchy="false">⟨</mo><msubsup><mrow><mi>ξ</mi></mrow><mrow><mn>2</mn><mo>;</mo><msub><mrow><mi>η</mi></mrow><mrow><mi>c</mi></mrow></msub></mrow><mrow><mn>2</mn></mrow></msubsup><mo stretchy="false">⟩</mo><mo>=</mo><mn>0.10</mn><msubsup><mrow><mn>3</mn></mrow><mrow><mo>−</mo><mn>0.009</mn></mrow><mrow><mo>+</mo><mn>0.009</mn></mrow></msubsup></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">⟨</mo><msubsup><mi>ξ</mi><mrow><mn>2</mn><mo>;</mo><msub><mi>η</mi><mi>c</mi></msub></mrow><mn>4</mn></msubsup><mo stretchy="false">⟩</mo><mo>=</mo><mn>0.03</mn><msubsup><mn>1</mn><mrow><mo>−</mo><mn>0.003</mn></mrow><mrow><mo>+</mo><mn>0.003</mn></mrow></msubsup></math>. Using these moments, we then fix the Gegenbauer expansion series of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>ϕ</mi><mrow><mn>2</mn><mo>;</mo><msub><mi>η</mi><mi>c</mi></msub></mrow></msub></math> and apply it to compute the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>B</mi><mi>c</mi></msub><mo stretchy="false">→</mo><msub><mi>η</mi><mi>c</mi></msub></math> transition form factors (TFFs) using QCD light cone sum rules. Second, we extrapolate those TFFs to physically allowable <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>q</mi><mn>2</mn></msup></math>-range via a simplified series expansion, and we obtain <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>R</mi></mrow><mrow><msub><mrow><mi>η</mi></mrow><mrow><mi>c</mi></mrow></msub></mrow></msub><msub><mrow><mo stretchy="false">|</mo></mrow><mrow><mi>SM</mi></mrow></msub><mo>=</mo><mn>0.30</mn><msubsup><mrow><mn>8</mn></mrow><mrow><mo>−</mo><mn>0.062</mn></mrow><mrow><mo>+</mo><mn>0.084</mn></mrow></msubsup></mrow></math>. Furthermore, we explore the potential impacts of various NP scenarios on <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>R</mi><msub><mi>η</mi><mi>c</mi></msub></msub></math>. Specifically, we compute the forward-backward asymmetry <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="script">A</mi><mi>FB</mi></msub><mo stretchy="false">(</mo><msup><mi>q</mi><mn>2</mn></msup><mo stretchy="false">)</mo></math>, the convexity parameter <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="script">C</mi><mi>F</mi><mi>τ</mi></msubsup><mo stretchy="false">(</mo><msup><mi>q</mi><mn>2</mn></msup><mo stretchy="false">)</mo></math>, and the longitudinal and transverse polarizations <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="script">P</mi><mi>L</mi></msub><mo stretchy="false">(</mo><msup><mi>q</mi><mn>2</mn></msup><mo stretchy="false">)</mo></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="script">P</mi><mi>T</mi></msub><mo stretchy="false">(</mo><msup><mi>q</mi><mn>2</mn></msup><mo stretchy="false">)</mo></math> for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>B</mi><mi>c</mi></msub><mo stretchy="false">→</mo><msub><mi>η</mi><mi>c</mi></msub></math> transitions within both the SM and two types of NP scenarios. Our results contribute to a deeper understanding of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>B</mi><mi>c</mi></msub></math>-meson semileptonic decays and provide insights into the search for the NP beyond the SM.

Long Zeng

Xing-Gang Wu

Dan-Dan Hu

Yu-Jie Zhang

Hai-Bing Fu

Tao Zhong

<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>η</mi><mi>c</mi></msub></math> leading-twist distribution amplitude and the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>B</mi></mrow><mrow><mi>c</mi></mrow></msub><mo stretchy="false">→</mo><msub><mrow><mi>η</mi></mrow><mrow><mi>c</mi></mrow></msub><mo>ℓ</mo><msub><mrow><mover accent="true"><mrow><mi>ν</mi></mrow><mrow><mo stretchy="false">¯</mo></mrow></mover></mrow><mrow><mo>ℓ</mo></mrow></msub></mrow></math> semileptonic decays using QCD sum rules

The decrease of the chiral pseudocritical temperature <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>T</mi><mrow><mi>p</mi><mi>c</mi></mrow></msub></math> with an applied strong magnetic field has been extensively investigated by various QCD low-energy effective models and lattice QCD at the physical point. We find that this decreasing feature may not hold in the case with a weak magnetic field and still depends on quark masses: when the quark masses get smaller, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>T</mi><mrow><mi>p</mi><mi>c</mi></mrow></msub></math> turns to increase with the weak magnetic field. This happens due to the significant electromagnetic scale anomaly contribution in the thermomagnetic medium. We demonstrate this salient feature by employing the Nambu-Jona-Lasinio model with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>2</mn><mo>+</mo><mn>1</mn></mrow></math> quark flavors including the electromagnetic scale anomaly contribution. We observe that at <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mo stretchy="false">(</mo><msub><mrow><mi>m</mi></mrow><mrow><mn>0</mn><mi>c</mi></mrow></msub><mo>,</mo><msub><mrow><mi>m</mi></mrow><mrow><mi>s</mi><mi>c</mi></mrow></msub><mo stretchy="false">)</mo><mo>≃</mo><mo stretchy="false">(</mo><mn>2</mn><mo>,</mo><mn>20</mn><mo stretchy="false">)</mo><mtext> </mtext><mtext> </mtext><mi>MeV</mi></mrow></math> for the isospin symmetric mass for up and down quarks, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><mn>0</mn></msub></math>, and the strange quark mass, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><mi>s</mi></msub></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>T</mi><mrow><mi>p</mi><mi>c</mi></mrow></msub></math> decreases with the magnetic field if the quark masses exceed the critical values, and increases as the quark masses become smaller. Related cosmological implications, arising when the supercooled electroweak phase transition or dark QCD cosmological phase transition is considered along with a primordial magnetic field, are also briefly addressed.

Yuanyuan Wang

Shinya Matsuzaki

Mamiya Kawaguchi

Japan

Akio Tomiya

Implications of the electromagnetic scale anomaly to the QCD chiral phase transition in the smaller quark mass regime: <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>T</mi><mrow><mi>p</mi><mi>c</mi></mrow></msub></math> does not drop with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>e</mi><mi>B</mi></math>

We introduce a class of multi-Higgs doublet extensions of the Standard Model that solve the strong <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><mi>P</mi></math> problem with profound consequences for the flavor sector. The Yukawa matrices are constrained to have many zero entries by a “Higgs-flavor” symmetry, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>G</mi><mi>HF</mi></msub></math>, that acts on Higgs and quark fields. The violation of both <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><mi>P</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>G</mi><mi>HF</mi></msub></math> occurs in the Higgs mass matrix so that, for certain choices of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>G</mi><mi>HF</mi></msub></math> charges, the strong <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><mi>P</mi></math> parameter <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mover accent="true"><mi>θ</mi><mo stretchy="false">¯</mo></mover></math> is zero at tree level. Radiative corrections to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mover accent="true"><mi>θ</mi><mo stretchy="false">¯</mo></mover></math> are computed in this class of theories. They vanish in realistic two-Higgs doublet models with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>G</mi><mi>HF</mi></msub><mo>=</mo><msub><mi mathvariant="double-struck">Z</mi><mn>3</mn></msub></math>. We also construct realistic three-Higgs models with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>G</mi><mi>HF</mi></msub><mo>=</mo><mi mathvariant="normal">U</mi><mo stretchy="false">(</mo><mn>1</mn><mo stretchy="false">)</mo></math>, where the one-loop results for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mover accent="true"><mi>θ</mi><mo stretchy="false">¯</mo></mover></math> are model-dependent. Requiring <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mover accent="true"><mi>θ</mi><mo stretchy="false">¯</mo></mover><mo>&lt;</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>10</mn></mrow></msup></math> has important implications for the flavor problem by constraining the Yukawa coupling and Higgs mass matrices. Contributions to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mover accent="true"><mi>θ</mi><mo stretchy="false">¯</mo></mover></math> from higher-dimension operators are computed at one loop and can also be sufficiently small, although the hierarchy problem of this class of theories is worse than in the Standard Model.

Lawrence Hall

Claudio Andrea Manzari

Bea Noether

Strong <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><mi>P</mi></math> and flavor in multi-Higgs theories

Energy-momentum tensor in general conformal field theories have improvement ambiguity and it can affect the argument in deriving c-theorem. While the derivation of Zamolodchikov’s c-theorem is still formally valid with the improved energy-momentum tensor, the behavior of the c-function proposed by Zamolodchikov becomes different. When the theory suffers an IR divergence due to the non-compactness, the c-function can be unbounded and may even show non-monotonicity. We find that one of the three-point function sum rule proposed by Hartman and Mathys motivated by the averaged null energy condition, however, is agnostic about the improvement and gives the (effective) Virasoro central charge, when the IR theory is gapped.

Nanami Nakamura

Yu Nakayama

c-theorem and improvement in non-compact conformal field theories

Fusion excitation functions for 19O and 19F + 12C were simultaneously measured along with 20O + 12C using the active-target detector MuSIC@Indiana. Examination of the cross-section just above the barrier reveals a significant suppression of fusion for the 19O + 12C system starting at E <math altimg='si1.svg'><mmultiscripts><mrow><mo>&#8764;</mo></mrow><mprescripts /><mrow><mi mathvariant='normal'>c</mi><mo>.</mo><mi mathvariant='normal'>m</mi><mo>.</mo></mrow><none /></mmultiscripts></math>12 MeV. This suppression is not simply due to the reduced binding of the unpaired neutron in 19O as 17O + 12C does not exhibit the same sharp suppression of the fusion cross-section. Multiple mean-field models are used as a reference to understand the measured fusion excitation functions.

H. Desilets

Rohit Kumar

R.T. deSouza

S. Hudan

France

C. Ciampi

A. Chbihi

K.W. Brown

K. Godbey

Brazil

B. Pinheiro

E.N. Cardozo

J. Lubian

Impact of pairing and neutron-excess on suppression of the above-barrier fusion cross-section in 19O + 12C

We systematically study the electromagnetic properties of pentaquark states from different perspectives to better understand their nature, internal structure, and quantum numbers, determine their hadronization processes, and shed light on their true nature. The present study examines the magnetic moments of the $$P_{c}(4457)$$ and related hidden-charm pentaquark states with and without strangeness $$([d d][u c] {\bar{c}},$$ $$[u u][s c] {\bar{c}},$$ $$[dd ][s c] {\bar{c}},$$ $$[s s][u c] {\bar{c}}$$ and $$[s s][d c] {\bar{c}})$$ , employing a comprehensive analysis that encompasses both the compact pentaquark configuration and $$J^P = \frac{3}{2}^-$$ quantum numbers. The present study compares the results regarding the magnetic moment of the $$P_{c}(4457)$$ pentaquark state with those reported in the existing literature. The numerical results obtained in this study, when considered alongside existing literature, indicate that the magnetic moments of hidden-charm pentaquark states may offer insights into their underlying structures, which in turn can inform the distinction between their spin-parity quantum numbers. It seems that for the future experimental search of the family of hidden-charm pentaquark states, studying the electromagnetic properties of the hidden-charm pentaquark states can provide valuable information.

Ulaş ÖZDEM

Insight into the nature of the $$P_{c}(4457)$$ and related pentaquarks