Using <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mo stretchy="false">(</mo><mn>10.087</mn><mo>±</mo><mn>0.044</mn><mo stretchy="false">)</mo><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mn>9</mn></mrow></msup><mtext> </mtext><mtext> </mtext><mi>J</mi><mo>/</mo><mi>ψ</mi></mrow></math> events collected with the BESIII detector at the <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> BEPCII collider, we present the first amplitude analysis of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>J</mi><mo>/</mo><mi>ψ</mi><mo stretchy="false">→</mo><mi>γ</mi><mi>p</mi><mover accent="true"><mi>p</mi><mo stretchy="false">¯</mo></mover></math> with the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>p</mi><mover accent="true"><mi>p</mi><mo stretchy="false">¯</mo></mover></math> invariant mass in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>η</mi><mi>c</mi></msub></math> mass region <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mo stretchy="false">[</mo><mn>2.70</mn><mo>,</mo><mn>3.05</mn><mo stretchy="false">]</mo><mtext> </mtext><mtext> </mtext><mi>GeV</mi><mo>/</mo><msup><mrow><mi>c</mi></mrow><mrow><mn>2</mn></mrow></msup></mrow></math>. The product branching fraction <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="script">B</mi><mo stretchy="false">(</mo><mi>J</mi><mo>/</mo><mi>ψ</mi><mo stretchy="false">→</mo><mi>γ</mi><msub><mrow><mi>η</mi></mrow><mrow><mi>c</mi></mrow></msub><mo stretchy="false">)</mo><mo>×</mo><mi mathvariant="script">B</mi><mo stretchy="false">(</mo><msub><mrow><mi>η</mi></mrow><mrow><mi>c</mi></mrow></msub><mo stretchy="false">→</mo><mi>p</mi><mover accent="true"><mrow><mi>p</mi></mrow><mrow><mo stretchy="false">¯</mo></mrow></mover><mo stretchy="false">)</mo></mrow></math> is determined to be <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mo stretchy="false">(</mo><mn>2.11</mn><mo>±</mo><mn>0.0</mn><msub><mrow><mn>2</mn></mrow><mrow><mi>stat</mi></mrow></msub><mo>±</mo><mn>0.0</mn><msub><mrow><mn>7</mn></mrow><mrow><mi>syst</mi></mrow></msub><mo stretchy="false">)</mo><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>5</mn></mrow></msup></mrow></math> with precision improved by 1 order of magnitude. Combining with the product branching fractions <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="script">B</mi><mo stretchy="false">(</mo><msub><mrow><mi>η</mi></mrow><mrow><mi>c</mi></mrow></msub><mo stretchy="false">→</mo><mi>p</mi><mover accent="true"><mrow><mi>p</mi></mrow><mrow><mo stretchy="false">¯</mo></mrow></mover><mo stretchy="false">)</mo><mo>×</mo><mi mathvariant="script">B</mi><mo stretchy="false">(</mo><msub><mrow><mi>η</mi></mrow><mrow><mi>c</mi></mrow></msub><mo stretchy="false">→</mo><mi>γ</mi><mi>γ</mi><mo stretchy="false">)</mo></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="script">B</mi><mo stretchy="false">(</mo><mi>J</mi><mo>/</mo><mi>ψ</mi><mo stretchy="false">→</mo><mi>γ</mi><msub><mrow><mi>η</mi></mrow><mrow><mi>c</mi></mrow></msub><mo stretchy="false">)</mo><mo>×</mo><mi mathvariant="script">B</mi><mo stretchy="false">(</mo><msub><mrow><mi>η</mi></mrow><mrow><mi>c</mi></mrow></msub><mo stretchy="false">→</mo><mi>γ</mi><mi>γ</mi><mo stretchy="false">)</mo></mrow></math>, the branching fractions of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">B</mi><mo stretchy="false">(</mo><mi>J</mi><mo>/</mo><mi>ψ</mi><mo stretchy="false">→</mo><mi>γ</mi><msub><mi>η</mi><mi>c</mi></msub><mo stretchy="false">)</mo></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">B</mi><mo stretchy="false">(</mo><msub><mi>η</mi><mi>c</mi></msub><mo stretchy="false">→</mo><mi>γ</mi><mi>γ</mi><mo stretchy="false">)</mo></math> are calculated to be <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mo stretchy="false">(</mo><mn>2.29</mn><mo>±</mo><mn>0.0</mn><msub><mrow><mn>1</mn></mrow><mrow><mi>stat</mi></mrow></msub><mo>±</mo><mn>0.0</mn><msub><mrow><mn>4</mn></mrow><mrow><mi>syst</mi></mrow></msub><mo>±</mo><mn>0.1</mn><msub><mrow><mn>8</mn></mrow><mrow><mi>opbf</mi></mrow></msub><mo stretchy="false">)</mo><mo>%</mo></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mo stretchy="false">(</mo><mn>2.28</mn><mo>±</mo><mn>0.0</mn><msub><mrow><mn>1</mn></mrow><mrow><mi>stat</mi></mrow></msub><mo>±</mo><mn>0.0</mn><msub><mrow><mn>4</mn></mrow><mrow><mi>syst</mi></mrow></msub><mo>±</mo><mn>0.1</mn><msub><mrow><mn>8</mn></mrow><mrow><mi>opbf</mi></mrow></msub><mo stretchy="false">)</mo><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>4</mn></mrow></msup></mrow></math>, respectively, which are consistent with the latest lattice quantum chromodynamics calculations. Here, opbf is the uncertainty from the other product branching fractions used in the calculation.

China

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. 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

Study of the Magnetic Dipole Transition of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>J</mi><mo>/</mo><mi>ψ</mi><mo stretchy="false">→</mo><mi>γ</mi><msub><mi>η</mi><mi>c</mi></msub></math> via <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>η</mi><mi>c</mi></msub><mo stretchy="false">→</mo><mi>p</mi><mover accent="true"><mi>p</mi><mo stretchy="false">¯</mo></mover></math>

Hidden-charm pentaquark states with double strangeness, $$P_{css}$$ , have been predicted within the framework of unitary coupled-channel dynamics. In this work, we theoretically investigate the potential to observe these states in the decays $$\Lambda _b\rightarrow J/\psi \Xi ^-K^+$$ and $$\Xi _b\rightarrow J/\psi \Xi ^-\pi ^+$$ . In this framework, these pentaquark configurations couple strongly to the $$J/\psi \Xi $$ channel, as well as to other vector-baryon channels with the $$\bar{c} c s s n$$ flavor structure, making these decay modes promising for their observation through the corresponding invariant-mass distributions. Our analysis begins with the identification of the dominant weak decay mechanisms, followed by hadronization into meson-baryon channels, connected through flavor symmetry. Final-state interactions are then incorporated to dynamically generate the full amplitude, accounting for the formation of the pentaquark states. We compare our results with recent LHCb measurements of the $$J/\psi \Xi ^-$$ mass distribution and find that, given the predicted pentaquark width of about 10 MeV in this channel, the state is too narrow to be resolved with the current experimental resolution, but it would become visible with significantly improved mass precision.

Spain

L. Roca

J. Song

E. Oset

Study of hidden-charm, doubly-strange pentaquarks in $$\Lambda _b\rightarrow J/\psi \Xi ^- K^+$$ and $$\Xi _b\rightarrow J/\psi \Xi ^- \pi ^+$$

In this work, we employ the quark-meson coupling model to investigate the mass shifts of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>1</mn><mi>P</mi></math>-wave charmonia <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>χ</mi><mrow><mi>c</mi><mi>J</mi></mrow></msub><mo stretchy="false">(</mo><mn>1</mn><mi>P</mi><mo stretchy="false">)</mo></math> (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>J</mi><mo>=</mo><mn>0</mn></math>, 1, 2) in cold symmetric nuclear matter by incorporating in-medium loop contributions to the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>χ</mi><mrow><mi>c</mi><mi>J</mi></mrow></msub><mo stretchy="false">(</mo><mn>1</mn><mi>P</mi><mo stretchy="false">)</mo></math> self-energy within the unquenched picture. At normal nuclear matter density, we obtain significant mass reductions of about 60 MeV for the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>χ</mi><mrow><mi>c</mi><mi>J</mi></mrow></msub><mo stretchy="false">(</mo><mn>1</mn><mi>P</mi><mo stretchy="false">)</mo></math> states, with the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>χ</mi><mrow><mi>c</mi><mn>2</mn></mrow></msub><mo stretchy="false">(</mo><mn>1</mn><mi>P</mi><mo stretchy="false">)</mo></math> mass shift primarily arising from the vector-vector loop. Our results also indicate the absence of level crossing between the in-medium <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>χ</mi><mrow><mi>c</mi><mi>J</mi></mrow></msub><mo stretchy="false">(</mo><mn>1</mn><mi>P</mi><mo stretchy="false">)</mo></math> mass and the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>D</mi><mover accent="true"><mi>D</mi><mo stretchy="false">¯</mo></mover></math> mass threshold up to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>ρ</mi><mi>B</mi></msub><mo>&lt;</mo><mn>3</mn><msub><mi>ρ</mi><mn>0</mn></msub></math>—a feature that could be probed in the compressed baryonic matter experiment at FAIR and the beam energy scan program at RHIC.

Ze-Hua Zhang

Xiang Liu

Medium modifications of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>1</mn><mi>P</mi></math>-wave charmonia <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>χ</mi><mrow><mi>c</mi><mi>J</mi></mrow></msub><mo stretchy="false">(</mo><mn>1</mn><mi>P</mi><mo stretchy="false">)</mo></math> in cold nuclear matter

We investigate the heavy quarkonium hybrid mesons with exotic quantum numbers <math altimg='si2.svg'><mrow><msup><mi>J</mi><mrow><mi>P</mi><mi>C</mi></mrow></msup><mo linebreak='goodbreak'>=</mo><msup><mn>2</mn><mrow><mo>+</mo><mo>&#8722;</mo></mrow></msup></mrow></math> via QCD sum rule method. We construct the currents with three Lorentz indices and calculate the correlation functions up to dimension six at the leading order of <italic>&#945;<inf>s</inf></italic>. The states with <math altimg='si2.svg'><mrow><msup><mi>J</mi><mrow><mi>P</mi><mi>C</mi></mrow></msup><mo linebreak='goodbreak'>=</mo><msup><mn>2</mn><mrow><mo>+</mo><mo>&#8722;</mo></mrow></msup></mrow></math> are extracted by constructing the corresponding projection operators. The obtained results indicate that the masses of <math altimg='si10.svg'><msup><mn>2</mn><mrow><mo>+</mo><mo>&#8722;</mo></mrow></msup></math> <math altimg='si1.svg'><mrow><mover accent='true'><mi>c</mi><mo>&#175;</mo></mover><mi>G</mi><mi>c</mi></mrow></math> and <math altimg='si4.svg'><mrow><mover accent='true'><mi>b</mi><mo>&#175;</mo></mover><mi>G</mi><mi>b</mi></mrow></math> hybrid states are about 4.49&#8201;GeV and 10.48&#8201;GeV, respectively. We suggest to search for <math altimg='si1.svg'><mrow><mover accent='true'><mi>c</mi><mo>&#175;</mo></mover><mi>G</mi><mi>c</mi></mrow></math> hybrid meson with <math altimg='si2.svg'><mrow><msup><mi>J</mi><mrow><mi>P</mi><mi>C</mi></mrow></msup><mo linebreak='goodbreak'>=</mo><msup><mn>2</mn><mrow><mo>+</mo><mo>&#8722;</mo></mrow></msup></mrow></math> in <italic>J</italic>/ <italic>&#968;f</italic> <inf>0,1,2</inf> and <italic>&#967;</italic> <inf><italic>c</italic>0,1,2</inf> <italic>&#969;</italic> final states.

Qi-Nan Wang

Ding-Kun Lian

Hua-Xing Chen

Wei Chen

Investigations on heavy quarkonium hybrid mesons with exotic quantum numbers <math altimg='si2.svg'><mrow><msup><mi>J</mi><mrow><mi>P</mi><mi>C</mi></mrow></msup><mo linebreak='goodbreak'>=</mo><msup><mn>2</mn><mrow><mo>+</mo><mo>&#8722;</mo></mrow></msup></mrow></math>

We perform a global Bayesian analysis of diffractive <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">J</mi><mo>/</mo><mi>ψ</mi></math> production in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>γ</mi><mo>+</mo><mi>p</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>γ</mi><mo>+</mo><mi>Pb</mi></math> collisions using a color glass condensate (CGC) based calculation framework. As past calculations have shown that CGC-based models typically overpredict the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">J</mi><mo>/</mo><mi>ψ</mi></math> production in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>γ</mi><mo>+</mo><mi>Pb</mi></math> collisions at high center of mass energy, we address the question of whether it is possible to describe coherent and incoherent diffractive <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">J</mi><mo>/</mo><mi>ψ</mi></math> data from <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>γ</mi><mo>+</mo><mi>p</mi></math> collisions at Hadron–Electron Ring Accelerator (HERA) and the LHC, and from <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>γ</mi><mo>+</mo><mi>Pb</mi></math> collisions at the LHC simultaneously. Our results indicate that a simultaneous description of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>γ</mi><mo>+</mo><mi>p</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>γ</mi><mo>+</mo><mi>Pb</mi></math> data is challenging, with results improving when an overall <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>K</mi></math>-factor—scaling <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>γ</mi><mo>+</mo><mi>p</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>γ</mi><mo>+</mo><mi>Pb</mi></math> cross sections to absorb model uncertainties—is introduced.

Finland

Heikki Mäntysaari

Hendrik Roch

Farid Salazar

Björn Schenke

Chun Shen

Wenbin Zhao

Global Bayesian analysis of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="normal">J</mi><mo>/</mo><mi>ψ</mi></mrow></math> photoproduction on proton and lead targets

This paper describes a measurement of the $$ {\Lambda}_b^0\to J/\psi \Lambda $$ branching fraction using data collected with the LHCb experiment in proton-proton collisions from 2016 to 2018. The dataset corresponds to an integrated luminosity of 5$\textit{.}$4 fb . The branching fraction is determined relative to that of $$ {B}^0\to J/\psi {K}_{\textrm{S}}^0 $$ decays,

Netherlands

R. Aaij

A. Abdelmotteleb

Switzerland

C. Abellan Beteta

F. Abudinén

T. Ackernley

A. Adefisoye

B. Adeva

M. Adinolfi

France

C. Agapopoulou

C. Aidala

Z. Ajaltouni

S. Akar

K. Akiba

M. Akthar

P. Albicocco

J. Albrecht

Lithuania

R. Aleksiejunas

F. Alessio

P. Alvarez Cartelle

R. Amalric

Brazil

S. Amato

J. Amey

Y. Amhis

L. An

L. Anderlini

M. Andersson

P. Andreola

M. Andreotti

S. Andres Estrada

A. Anelli

D. Ao

C. Arata

F. Archilli

Z. Areg

M. Argenton

Costa Rica

S. Arguedas Cuendis

L. Arnone

A. Artamonov

M. Artuso

E. Aslanides

R. Ataíde Da Silva

M. Atzeni

B. Audurier

J. Authier

D. Bacher

I. Bachiller Perea

S. Bachmann

M. Bachmayer

J. Back

P. Baladron Rodriguez

V. Balagura

A. Balboni

W. Baldini

Z. Baldwin

L. Balzani

H. Bao

J. Baptista de Souza Leite

C. Barbero Pretel

M. Barbetti

Measurement of the branching fraction of the $$ {\Lambda}_b^0\to J/\psi \Lambda $$ decay and isospin asymmetry of $\textit{B → J/ψK}$ decays