<p>Using data samples with a total integrated luminosity of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>253</mn><mtext> </mtext><mtext> </mtext><msup><mrow><mi>pb</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></math> collected by the BESIII detector operating at the BEPCII collider, the differential cross sections of inclusive <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>π</mi><mo>±</mo></msup></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>K</mi><mo>±</mo></msup></math> production, as a function of the momentum and normalized by the total hadronic cross section, are measured at center-of-mass energies from 2.000 to 3.671 GeV. The measured <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>π</mi><mo>±</mo></msup></math> cross sections are consistent with the previously reported <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>π</mi><mn>0</mn></msup></math> cross sections by BESIII, while the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>K</mi><mo>±</mo></msup></math> cross sections are systematically higher than the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>K</mi><mi>S</mi><mn>0</mn></msubsup></math> cross sections by a factor of approximately 1.4. These new results are in agreement with state-of-the-art QCD analyses at next-to-next-to-leading-order accuracy, particularly in the large hadron momentum region at energy scales down to 3 GeV. These findings support the validity of isospin symmetry in parton fragmentation processes.</p>

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

G. Chelkov

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

Z.H. 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

Single Inclusive <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>π</mi></mrow><mrow><mo>±</mo></mrow></msup></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>K</mi></mrow><mrow><mo>±</mo></mrow></msup></mrow></math> Production in <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> Annihilation at Center-of-Mass Energies from 2.000 to 3.671 GeV

We perform a theoretical study of the weak decay $$\Lambda _c^+ \rightarrow \bar{K}^0 \eta p$$ using a coupled-channel chiral unitary approach that incorporates both pseudoscalar-baryon and vector-baryon interactions. Our framework includes contributions from both internal and external weak emission mechanisms, as well as strong final state interactions. We assume that the $$N^*(1535)$$ and $$N^*(1650)$$ resonances are dynamically generated through meson-baryon scattering and they appear as distinct structures in the $$\eta p$$ invariant mass distributions. A clear peak also appears in the $$\bar{K}^0 p$$ invariant mass distribution around 1620 MeV, associated with the dynamically generated $$\Sigma (1620)$$ resonance. Notably, this work provides the first theoretical description of the simultaneous observation of these two related $$N^*$$ resonances in the same meson-baryon final state. Our results highlight the crucial role of final state interaction and the interplay between different weak decay topologies in shaping the resonance patterns. These findings offer new insights into the nature of nucleon excitations and support the interpretation of $$N^*(1535)$$ and $$N^*(1650)$$ as dynamically generated states. Moreover, the identification of the $$\Sigma (1620)$$ further supports the picture of hadronic molecular structures emerging from meson-baryon interactions in the non-perturbative QCD regime.

Spain

Jing Song

Melahat Bayar

Yi-Yao Li

Eulogio Oset

Revisiting the $$\Lambda _c^+\rightarrow \bar{K}^0\eta p$$ reaction: the role of $$N^*(1535),$$ $$N^*(1650)$$ and $$\Sigma (1620)$$

<p>We present a search for the rare flavor-changing neutral-current decay <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>B</mi></mrow><mrow><mn>0</mn></mrow></msup><mo stretchy="false">→</mo><msup><mrow><mi>K</mi></mrow><mrow><mo>*</mo><mn>0</mn></mrow></msup><mrow><msup><mrow><mi>τ</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>τ</mi></mrow><mrow><mo>−</mo></mrow></msup></mrow></mrow></math> with data collected by the Belle II experiment at the SuperKEKB electron-positron collider. The analysis uses a <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>365</mn><mtext> </mtext><mtext> </mtext><msup><mrow><mi>fb</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></math> data sample recorded at the center-of-mass energy of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="normal">ϒ</mi><mrow><mo stretchy="false">(</mo><mrow><mn>4</mn><mi>S</mi></mrow><mo stretchy="false">)</mo></mrow></mrow></math> resonance. One of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi></math> mesons produced in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mrow><mi mathvariant="normal">ϒ</mi><mrow><mo stretchy="false">(</mo><mrow><mn>4</mn><mi>S</mi></mrow><mo stretchy="false">)</mo></mrow></mrow><mo stretchy="false">→</mo><msup><mrow><mi>B</mi></mrow><mrow><mn>0</mn></mrow></msup><mrow><msup><mrow><mover accent="true"><mrow><mi>B</mi></mrow><mrow><mo stretchy="false">¯</mo></mrow></mover></mrow><mrow><mn>0</mn></mrow></msup></mrow></mrow></math> process is fully reconstructed in a hadronic decay mode, while its companion <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi></math> meson is required to decay into a <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>K</mi></mrow><mrow><mo>*</mo><mn>0</mn></mrow></msup></mrow></math> and two <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>τ</mi></math> leptons of opposite charge. The <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>τ</mi></math> leptons are reconstructed in final states with a single electron, muon, charged pion or charged <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>ρ</mi></math> meson, and additional neutrinos. We set an upper limit on the branching fraction of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="script">B</mi><mo stretchy="false">(</mo><mrow><msup><mrow><mi>B</mi></mrow><mrow><mn>0</mn></mrow></msup><mo stretchy="false">→</mo><msup><mrow><mi>K</mi></mrow><mrow><mo>*</mo><mn>0</mn></mrow></msup><msup><mrow><mi>τ</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>τ</mi></mrow><mrow><mo>−</mo></mrow></msup></mrow><mo stretchy="false">)</mo><mo>&lt;</mo><mrow><mn>1.8</mn><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>3</mn></mrow></msup></mrow></mrow></math> at the 90% confidence level, which is the most stringent constraint reported to date.</p>

I. Adachi

K. Adamczyk

L. Aggarwal

H. Ahmed

H. Aihara

N. Akopov

M. Alhakami

A. Aloisio

N. Althubiti

M. Angelsmark

N. Anh Ky

D.M. Asner

H. Atmacan

V. Aushev

M. Aversano

R. Ayad

V. Babu

H. Bae

N.K. Baghel

S. Bahinipati

P. Bambade

Sw. Banerjee

S. Bansal

M. Barrett

M. Bartl

J. Baudot

A. Baur

A. Beaubien

F. Becherer

J. Becker

J.V. Bennett

F.U. Bernlochner

V. Bertacchi

M. Bertemes

E. Bertholet

M. Bessner

S. Bettarini

V. Bhardwaj

B. Bhuyan

T. Bilka

D. Biswas

A. Bobrov

D. Bodrov

A. Bolz

A. Bondar

A. Boschetti

A. Bozek

M. Bračko

P. Branchini

N. Brenny

T.E. Browder

A. Budano

S. Bussino

Q. Campagna

M. Campajola

L. Cao

G. Casarosa

C. Cecchi

J. Cerasoli

M.C. Chang

P. Chang

R. Cheaib

P. Cheema

B.G. Cheon

K. Chilikin

J. Chin

K. Chirapatpimol

H.E. Cho

K. Cho

S.J. Cho

S. Choudhury

J. Cochran

I. Consigny

L. Corona

J.X. Cui

E. De La Cruz-Burelo

S.A. De La Motte

G. de Marino

G. De Nardo

G. De Pietro

R. de Sangro

S. Dey

R. Dhamija

Search for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>B</mi></mrow><mrow><mn>0</mn></mrow></msup><mo stretchy="false">→</mo><msup><mrow><mi>K</mi></mrow><mrow><mo>*</mo><mn>0</mn></mrow></msup><msup><mrow><mi>τ</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>τ</mi></mrow><mrow><mo>−</mo></mrow></msup></mrow></math> Decays at the Belle II Experiment