In the present work, the strong decays of the discovered $ P_c(4380) $ , $ P_c(4440) $ , $ P_c(4457) $ and their possible isospin cousins are systematically studied via the assignment that they are meson-baryon molecular states. In detail, the strong decay constants and partial decay widths of their decay channels are calculated under the framework of QCD sum rules. The decay widths of the discovered $ P_c(4380) $ , $ P_c(4440) $ , and $ P_c(4457) $ are in good agreement with the experiments. The predictions of the decays of these three related possible isospin cousins are presented, which would shed light on their findings in experiments. In return, this may testify to the assignments of the discovered $ P_c $ states.

China

Xiu-Wu Wang

Xin Li

Zhi-Gang Wang

Systematic study of the strong decays of the $\textit{P}$ $\textit{c}$ states and their possible isospin cousins via the QCD sum rules * Supported by the National Natural Science Foundation of China (12575083) and the Natural Science Foundation of Hebei Province (A2024502002)

The <italic>&#947;d</italic>&#8239;&#8594;&#8239; <italic>K</italic> 0&#923; <italic>p</italic> reaction has been studied to search for a <math altimg='si30.svg'><mrow><mover accent='true'><mi>K</mi><mo>&#175;</mo></mover><mi>N</mi><mi>N</mi></mrow></math> quasi-bound state using the LEPS2 solenoid spectrometer at SPring-8. A localized enhancement concentrated at low <italic>q</italic> is observed in the ( <italic>M</italic> <inf>&#923;<italic>p</italic></inf>, <italic>q</italic>) distribution below the <math altimg='si8.svg'><mrow><msup><mi>K</mi><mo>&#8722;</mo></msup><mi>p</mi><mi>p</mi></mrow></math> mass threshold, where <italic>M</italic> <inf>&#923;<italic>p</italic></inf> is the &#923; <italic>p</italic> invariant mass and <math altimg='si31.svg'><mrow><mrow><mi>q</mi><mo>&#8801;</mo><mo>|</mo></mrow><msub><mover accent='true'><mi>p</mi><mo>&#8594;</mo></mover><mi>&#947;</mi></msub><mo linebreak='goodbreak'>&#8722;</mo><msub><mover accent='true'><mi>p</mi><mo>&#8594;</mo></mover><msup><mi>K</mi><mn>0</mn></msup></msub><mrow><mo>|</mo><mo>=</mo><mo>|</mo></mrow><msub><mover accent='true'><mi>p</mi><mo>&#8594;</mo></mover><mrow><mstyle mathvariant='normal'><mi>&#923;</mi></mstyle><mi>p</mi></mrow></msub><mrow><mo>|</mo></mrow></mrow></math> is the momentum transfer. A two-dimensional ( <italic>M</italic> <inf>&#923;<italic>p</italic></inf>, <italic>q</italic>) fit demonstrates that the enhancement near the threshold is statistically significant, yielding a local significance of 7.3&#8201; <italic>&#963;</italic>. The enhancement is characterized by effective shape parameters including the Breit&#8211;Wigner mass <italic>M</italic> and width &#915;, and a Gaussian form-factor momentum scale <italic>Q</italic>: <math altimg='si32.svg'><mrow><mi>M</mi><mo linebreak='goodbreak'>=</mo><mn>2.354</mn><mo>&#177;</mo><mn>0.011</mn><msubsup><mrow><mo>(</mo><mrow><mtext>stat</mtext><mo>.</mo></mrow><mo>)</mo></mrow><mrow><mo>&#8722;</mo><mn>0.005</mn></mrow><mrow><mo>+</mo><mn>0.009</mn></mrow></msubsup><mrow><mo>(</mo><mrow><mtext>syst</mtext><mo>.</mo></mrow><mo>)</mo></mrow><mspace width='0.33em' /><mtext>GeV</mtext><mo linebreak='goodbreak'>/</mo><msup><mi>c</mi><mn>2</mn></msup></mrow></math>, <math altimg='si33.svg'><mrow><mstyle mathvariant='normal'><mi>&#915;</mi></mstyle><mo linebreak='goodbreak'>=</mo><mn>0.055</mn><mo>&#177;</mo><mn>0.023</mn><msubsup><mrow><mo>(</mo><mrow><mtext>stat</mtext><mo>.</mo></mrow><mo>)</mo></mrow><mrow><mo>&#8722;</mo><mn>0.009</mn></mrow><mrow><mo>+</mo><mn>0.031</mn></mrow></msubsup><mrow><mo>(</mo><mrow><mtext>syst</mtext><mo>.</mo></mrow><mo>)</mo></mrow><mspace width='0.33em' /><mtext>GeV</mtext><mo linebreak='goodbreak'>/</mo><msup><mi>c</mi><mn>2</mn></msup></mrow></math>, and <math altimg='si34.svg'><mrow><mi>Q</mi><mo linebreak='goodbreak'>=</mo><mn>0.350</mn><mo>&#177;</mo><mn>0.041</mn><msubsup><mrow><mo>(</mo><mrow><mtext>stat</mtext><mo>.</mo></mrow><mo>)</mo></mrow><mrow><mo>&#8722;</mo><mn>0.010</mn></mrow><mrow><mo>+</mo><mn>0.035</mn></mrow></msubsup><mrow><mo>(</mo><mrow><mtext>syst</mtext><mo>.</mo></mrow><mo>)</mo></mrow><mspace width='0.33em' /><mtext>GeV</mtext><mo linebreak='goodbreak'>/</mo><mi>c</mi></mrow></math>. The obtained results support the existence of a <math altimg='si30.svg'><mrow><mover accent='true'><mi>K</mi><mo>&#175;</mo></mover><mi>N</mi><mi>N</mi></mrow></math> quasi-bound state in photoproduction.

Japan

R. Kobayakawa

South Korea

J.K. Ahn

S. Ajimura

Taiwan

W.C. Chang

M.L. Chu

S. Daté

T. Gogami

T.A. Hashimoto

T. Hotta

T. Ishikawa

H. Katsuragawa

H. Kohri

Y. Ma

M. Miyabe

K. Mizutani

N. Muramatsu

T. Nakano

Vietnam

T.H. Nam

M. Niiyama

Y. Nozawa

Y. Ohashi

H. Ohkuma

H. Ohnishi

T. Ohta

Canada

C. Rangacharyulu

S.Y. Ryu

Y. Sada

H. Shimizu

M. Sumihama

S. Suzuki

S. Tanaka

A.O. Tokiyasu

N. Tomida

K. Watanabe

T. Yorita

C. Yoshida

M. Yosoi

Evidence for a <math altimg='si30.svg'><mrow><mover accent='true'><mi>K</mi><mo>&#175;</mo></mover><mi>N</mi><mi>N</mi></mrow></math> quasi-bound state in the <italic>&#947;d</italic>&#8239;&#8594;&#8239; <italic>K</italic> 0&#923; <italic>p</italic> reaction

As the lightest isovector vector meson, the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>ρ</mi></math> meson is an important object for investigating the structure of resonant states in strong interactions. Owing to its strong coupling to the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>π</mi><mi>π</mi></math> channel and its large decay width, the conventional constituent quark model treatment, in which it is simply regarded as a pure <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>q</mi><mover accent="true"><mi>q</mi><mo stretchy="false">¯</mo></mover></math> bound state while the hadronic-channel coupling effects are neglected, is insufficient to fully characterize its physical properties. To this end, in the present work we establish a unified framework for studying the structure and resonant properties of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>ρ</mi></math> meson by combining the quark-gluon and hadronic degrees of freedom. At the quark-gluon level, we first determine the parameters of the chiral quark model by refitting a set of narrow mesons for which open Okubo-Zweig-Iizuka-allowed strong-decay channels are absent or strongly suppressed. With these parameters fixed, the bare mass of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>ρ</mi></math> meson is obtained and used as the input for the subsequent hadronic-level analysis. At the hadronic level, based on inverse-scattering theory, we construct a model including the coupling between the bare state and the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>π</mi><mi>π</mi></math> continuum, extract the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>ρ</mi><mn>0</mn></msub><mo>−</mo><mi>π</mi><mi>π</mi></math> interaction using the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>P</mi></math>-wave <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>π</mi><mi>π</mi></math> scattering phase-shift data, and further calculate the width of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>ρ</mi></math> meson as well as the bare-state component in the physical state. The present work also provides a generalizable analytical framework for further studies of other hadronic resonances with significant coupled-channel effects.

Wen-Ze Zhao

Ru-Hui Ni

Jia-Jun Wu

How to understand the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>ρ</mi></math> resonance from the quark model and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>π</mi><mi>π</mi></mrow></math> <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>P</mi></mrow></math>-wave phase shift

We develop a universal seesaw version of the Pati-Salam model wherein quarks and leptons of each family are unified into common multiplets transforming as {$\textit{ψ}$ (2, 1, 4) + $\textit{ψ}$ (1, 2, 4)} under the SU(2) × SU(2) × SU(4) gauge symmetry. Parity symmetry is spontaneously broken in the model, which helps in solving the strong CP problem without the axion. The Higgs sector of the model is very simple, consisting of a single pair of {$\textit{H}$ (2, 1, 4) + $\textit{H}$ (1, 2, 4)} fields. Fermion masses arise through mixing of the chiral fermions with vector-like quarks and leptons contained in (1, 1, 15) as well as {(1, 1, 10) + (1, 1, 10) } multiplets via a universal seesaw mechanism. Consistency of such a spectrum with the observed quark and lepton masses is established. The parity solution to the strong CP problem is shown to be effective in this framework, although there are new loop contributions to $$ \overline{\theta} $$ , compared to the analogous left-right symmetric model, arising from color sextet and octet fermions, as well as from diagrams mediated by leptoquark bosons. We also find that, in this setup, although lepton number is broken, neutrino masses remain zero at the tree-level. Small and finite Majorana neutrino masses are induced via one-loop diagrams, which we analyze and show to be compatible with oscillation experiments.

United States

K. Babu

Sumit Biswas

Universal seesaw Pati-Salam model with P for strong CP

Based on a novel method for producing antineutrons via <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>J</mi><mo>/</mo><mi>ψ</mi></math> decays, we report a study of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mover accent="true"><mi>n</mi><mo stretchy="false">¯</mo></mover><mi>p</mi></math> inelastic scattering into final states containing kaons. The analysis uses <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mo stretchy="false">(</mo><mn>10</mn><mtext> </mtext><mn>087</mn><mo>±</mo><mn>44</mn><mo stretchy="false">)</mo><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mn>6</mn></mrow></msup><mtext> </mtext><mtext> </mtext><mi>J</mi><mo>/</mo><mi>ψ</mi></mrow></math> events collected at the BESIII detector operating at the BEPCII storage ring. Antineutrons are produced via <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>J</mi><mo>/</mo><mi>ψ</mi><mo stretchy="false">→</mo><mi>p</mi><msup><mi>π</mi><mo>−</mo></msup><mover accent="true"><mi>n</mi><mo stretchy="false">¯</mo></mover></math> decays and tagged by the detected protons and pions, resulting in antineutron momenta ranging from 0 to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>1174</mn><mtext> </mtext><mtext> </mtext><mi>MeV</mi><mo>/</mo><mi>c</mi></mrow></math>, while target protons are provided by the hydrogen in the beam-pipe material. The flux-averaged cross sections of the reactions <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mover accent="true"><mi>n</mi><mo stretchy="false">¯</mo></mover><mi>p</mi><mo stretchy="false">→</mo><msup><mi>K</mi><mo>+</mo></msup><msup><mi>K</mi><mo>−</mo></msup><msup><mi>π</mi><mo>+</mo></msup></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mover accent="true"><mi>n</mi><mo stretchy="false">¯</mo></mover><mi>p</mi><mo stretchy="false">→</mo><msup><mi>K</mi><mo>+</mo></msup><msup><mi>K</mi><mo>−</mo></msup><msup><mi>π</mi><mo>+</mo></msup><msup><mi>π</mi><mn>0</mn></msup></math> over this antineutron momentum spectrum are measured to be <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mn>0.53</mn><mrow><mo>−</mo><mn>0.12</mn></mrow><mrow><mo>+</mo><mn>0.15</mn></mrow></msubsup><mo>±</mo><mn>0.08</mn><mtext> </mtext><mtext> </mtext><mi>mb</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mn>1.09</mn><mrow><mo>−</mo><mn>0.30</mn></mrow><mrow><mo>+</mo><mn>0.36</mn></mrow></msubsup><mo>±</mo><mn>0.31</mn><mtext> </mtext><mtext> </mtext><mi>mb</mi></math>, respectively, where the first uncertainties are statistical and the second are systematic. Due to limited statistics, the contributions of intermediate states remain speculative. The observation of clean antineutron-proton scattering candidates indicates the potential of this approach for future investigations of antineutron-proton interactions.

M. Ablikim

Russia

M.N. Achasov

Sweden

P. Adlarson

X.C. Ai

Italy

C.S. Akondi

Germany

R. Aliberti

A. Amoroso

Q. An

Y.H. An

Y. Bai

JINR

O. Bakina

Y. Ban

H.R. Bao

X.L. Bao

Poland

V. Batozskaya

Mongolia

K. Begzsuren

N. Berger

M. Berlowski

M.B. Bertani

D. Bettoni

F. Bianchi

E. Bianco

A. Bortone

I. Boyko

R.A. Briere

A. Brueggemann

D. Cabiati

H. Cai

M.H. Cai

X. Cai

A. Calcaterra

G.F. Cao

N. Cao

Türkiye

S.A. Cetin

X.Y. Chai

J.F. Chang

T.T. 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.M. Chen

T. Chen

W. Chen

X.R. Chen

X.T. Chen

X.Y. Chen

Y.B. Chen

Y.Q. Chen

Z.K. Chen

J. Cheng

L.N. Cheng

S.K. Choi

X. Chu

G. Cibinetto

F. Cossio

United Kingdom

J. Cottee-Meldrum

H.L. Dai

J.P. Dai

X.C. Dai

A. Dbeyssi

R.E. de Boer

D. Dedovich

C.Q. Deng

Z.Y. Deng

A. Denig

I. Denisenko

M. Destefanis

F. De Mori

X.X. Ding

Y. Ding

Y.X. Ding

Yi. Ding

J. Dong

L.Y. Dong

M.Y. Dong

X. Dong

M.C. Du

S.X. Du

Shaoxu Du

X.L. Du

Y.Q. Du

Y.Y. Duan

Z.H. Duan

P. Egorov

G.F. Fan

J.J. Fan

Y.H. Fan

J. Fang

Jin Fang

S.S. Fang

W.X. Fang

Y.Q. Fang

L. Fava

F. Feldbauer

Cross-section measurements of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mover accent="true"><mi>n</mi><mo stretchy="false">¯</mo></mover><mi>p</mi><mo stretchy="false">→</mo><msup><mi>K</mi><mo>+</mo></msup><msup><mi>K</mi><mo>−</mo></msup><msup><mi>π</mi><mo>+</mo></msup><mo stretchy="false">(</mo><msup><mi>π</mi><mn>0</mn></msup><mo stretchy="false">)</mo></math> via antineutrons produced by <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>J</mi><mo>/</mo><mi>ψ</mi><mo stretchy="false">→</mo><mi>p</mi><msup><mi>π</mi><mo>−</mo></msup><mover accent="true"><mi>n</mi><mo stretchy="false">¯</mo></mover></math> decays

A combination of measurements of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><mi>P</mi></math> properties of Higgs boson interactions with electroweak gauge bosons is presented, using <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>140</mn><mtext> </mtext><mtext> </mtext><msup><mi>fb</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math> of proton-proton collisions at <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msqrt><mrow><mi>s</mi></mrow></msqrt><mo>=</mo><mn>13</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi></mrow></math> recorded by the ATLAS detector. Results from vector boson fusion <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>H</mi><mo stretchy="false">→</mo><mi>τ</mi><mi>τ</mi><mo>/</mo><mi>W</mi><msup><mrow><mi>W</mi></mrow><mrow><mo>*</mo></mrow></msup><mo>/</mo><mi>γ</mi><mi>γ</mi></mrow></math>, inclusive <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>H</mi><mo stretchy="false">→</mo><mi>Z</mi><msup><mrow><mi>Z</mi></mrow><mrow><mo>*</mo></mrow></msup></mrow></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>W</mi><mi>H</mi><mo>,</mo><mi>H</mi><mo stretchy="false">→</mo><mi>b</mi><mover accent="true"><mrow><mi>b</mi></mrow><mrow><mo stretchy="false">¯</mo></mrow></mover></mrow></math> channels are combined. No evidence of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><mi>P</mi></math> violation is observed, and constrains on the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><mi>P</mi></math>-violating operators in the Standard Model effective field theory framework (SMEFT) are set in the Warsaw basis. The results from the combination improve by over 40% on previous individual limits on <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>c</mi><mrow><mi>H</mi><mover accent="true"><mi>W</mi><mo stretchy="false">˜</mo></mover></mrow></msub></math> and, for the first time, simultaneous constraints on three coefficients <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>c</mi><mrow><mi>H</mi><mover accent="true"><mi>W</mi><mo stretchy="false">˜</mo></mover></mrow></msub></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>c</mi><mrow><mi>H</mi><mover accent="true"><mi>B</mi><mo stretchy="false">˜</mo></mover></mrow></msub></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>c</mi><mrow><mi>H</mi><mover accent="true"><mi>W</mi><mo stretchy="false">˜</mo></mover><mi>B</mi></mrow></msub></math> are set. These limits are the most stringent constraints to date on the relevant Wilson coefficients in the SMEFT framework with minimum model dependence.

France

G. Aad

Norway

E. Aakvaag

B. Abbott

United Arab Emirates

S. Abdelhameed

K. Abeling

N.J. Abicht

S.H. Abidi

M. Aboelela

Morocco

A. Aboulhorma

Israel

H. Abramowicz

B.S. Acharya

A. Ackermann

C. Adam Bourdarios

L. Adamczyk

S.V. Addepalli

M.J. Addison

J. Adelman

A. Adiguzel

T. Adye

A.A. Affolder

Y. Afik

Spain

M.N. Agaras

A. Aggarwal

Combination of Measurements of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><mi>P</mi></math> Properties of Higgs Boson Interactions with Vector Bosons Using Proton-Proton Collisions at <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msqrt><mrow><mi>s</mi></mrow></msqrt><mo>=</mo><mn>13</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi></mrow></math> with the ATLAS Detector