Several possible excesses around $ 95 $ GeV hint at an additional light scalar beyond the Standard Model. We examine the capability of the Circular Electron-Positron Collider (CEPC) to test this hypothesis in the Higgs-strahlung channel $ e^{+}e^{-} \to ZS $ with $ Z \to\mu^{+}\mu^{-} $ and $ S \to\tau^{+}\tau^{-} $ . A full detector simulation shows that the optimal center-of-mass energy for studying the 95 GeV light scalar is 210 GeV. A deep neural network classifier reduces the luminosity required for discovery by half. At $ L = 20\; \mathrm{ab}^{-1} $ , the $ 5\sigma $ sensitivity of the CEPC to the signal strength $ \mu_{\tau\tau}^{ZS} $ reaches 0.016 and 0.020 for $ \sqrt{s} = 210 $ GeV and 240 GeV, respectively. The corresponding thresholds for a 5% precision measurement are $ \mu_{\tau\tau}^{ZS} \gt 0.10 $ and $ \gt 0.12 $ . At $ \sqrt{s}=210 $ GeV (240 GeV), the $ 5\sigma $ coverage of all N2HDM-Flipped samples with $ \chi^2_{h_{95}} \lt 7.82 $ requires $ L=800\ \mathrm{fb}^{-1} $ (1.22 $ \mathrm{ab}^{-1} $ ). These results establish a 210 GeV run, augmented by machine-learning selection, as the most efficient strategy to confirm or refute the 95 GeV excess at future lepton colliders.

China

Yabo Dong

Manqi Ruan

Kun Wang

Haijun Yang

Jingya Zhu

Testing a 95 GeV Scalar at the CEPC with Machine Learning * This work was supported by the National Natural Science Foundation of China under Grant No. 12275066 and by the startup research funds of Henan University. The work of K. Wang was also supported by the Open Project of the Shanghai Key Laboratory of Particle Physics and Cosmology under Grant No. 22DZ2229013-3. The work of M. Ruan was also supported by the National Key Program for S&T Research and Development under Contract No. 2024YFA1610603. The work of H. Yang was also supported by the National Natural Science Foundation of China under Grant No. W2441004.

An analytical and numerical systematic study of the neutrino mass matrix with one texture zero is presented in a basis where the charged leptons are diagonal. Under the assumption that neutrinos are Dirac particles, the analysis is conducted in detail for the normal and inverted hierarchy mass spectra. Our study is performed without any approximations, first analytically and then numerically, using current neutrino oscillation data. The analysis constrains the parameter space in such a way that, among the six possible one-texture-zero patterns, only four are favored in the normal hierarchy and one in the inverted hierarchy by current oscillation data at the $3 \sigma$ level. Phenomenological implications for the lepton CP-violating phase and neutrino masses are also explored.

Colombia

Richard H. Benavides

Yessica Lenis

John D. Gómez

William A. Ponce

One texture zero for Dirac neutrinos in a diagonal charged lepton basis * Richard H. Benavides acknowledges additional financial support from Minciencias (CD82315 CT ICETEX 2021-1080)

One-loop contributions for the decay process $ H^{\pm} \rightarrow W^{\pm}Z $ within the Two-Higgs-Doublet Model (THDM) are computed in the general $ {\cal{R}}_{\xi} $ gauge, and its phenomenological applications at future muon–TeV colliders are investigated. Analytic results are confirmed by several consistency tests, including those of $\textit{ξ}$-independence, renormalization-scale stability, and the ultraviolet finiteness of the one-loop amplitude. We first perform an updated parameter scan of the Type-X THDM in phenomenological studies. The production of charged Higgs boson pairs at future muon–TeV colliders is then investigated through two processes: $ \mu^+\mu^- \rightarrow H^+H^- \rightarrow W^{\pm}W^{\mp}Zh $ and $ \mu^+\mu^- \rightarrow \gamma\gamma \rightarrow H^+H^- \rightarrow W^{\pm}W^{\mp}Zh $ . Both signal events and their significance are evaluated considering the corresponding Standard Model backgrounds. We find that the signal significances can exceed $ 5\sigma $ at several benchmark points in the viable parameter space of the Type-X THDM.

Vietnam

Dzung Tri Tran

Quang Hoang-Minh Pham

Khoa Ngo-Thanh Ho

Khiem Hong Phan

One-loop expressions for ${H^\pm \rightarrow W^\pm Z} $ and their implications at muon-TeV colliders * This research is funded by Vietnam National Foundation for Science and Technology Development (NAFOSTED) (103.01-2023.16)

<p>We report decay-rate <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><mi>P</mi></math> asymmetries of the singly-Cabibbo-suppressed decays <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msubsup><mrow><mi mathvariant="normal">Ξ</mi></mrow><mrow><mi>c</mi></mrow><mrow><mo>+</mo></mrow></msubsup><mo stretchy="false">→</mo><mrow><msup><mrow><mi mathvariant="normal">Σ</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>h</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>h</mi></mrow><mrow><mo>−</mo></mrow></msup></mrow></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msubsup><mrow><mi mathvariant="normal">Λ</mi></mrow><mrow><mi>c</mi></mrow><mrow><mo>+</mo></mrow></msubsup><mo stretchy="false">→</mo><mrow><mi>p</mi><msup><mrow><mi>h</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>h</mi></mrow><mrow><mo>−</mo></mrow></msup></mrow></mrow></math>, with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>h</mi><mo>=</mo><mi>K</mi></mrow></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>π</mi></mrow></math>, measured using <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>428</mn><mtext> </mtext><mtext> </mtext><msup><mi>fb</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math> of <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> collisions collected by the Belle II experiment at the SuperKEKB collider. The results, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>A</mi></mrow><mrow><mi>C</mi><mi>P</mi></mrow></msub><mo stretchy="false">(</mo><msubsup><mrow><mi mathvariant="normal">Ξ</mi></mrow><mrow><mi>c</mi></mrow><mrow><mo>+</mo></mrow></msubsup><mo stretchy="false">→</mo><mrow><msup><mrow><mi mathvariant="normal">Σ</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>K</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>K</mi></mrow><mrow><mo>−</mo></mrow></msup></mrow><mo stretchy="false">)</mo><mo>=</mo><mo stretchy="false">(</mo><mn>3.7</mn><mo>±</mo><mn>6.6</mn><mo>±</mo><mn>0.6</mn><mo stretchy="false">)</mo><mo>%</mo></mrow></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>A</mi></mrow><mrow><mi>C</mi><mi>P</mi></mrow></msub><mo stretchy="false">(</mo><msubsup><mrow><mi mathvariant="normal">Ξ</mi></mrow><mrow><mi>c</mi></mrow><mrow><mo>+</mo></mrow></msubsup><mo stretchy="false">→</mo><mrow><msup><mrow><mi mathvariant="normal">Σ</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>π</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>π</mi></mrow><mrow><mo>−</mo></mrow></msup></mrow><mo stretchy="false">)</mo><mo>=</mo><mo stretchy="false">(</mo><mn>9.5</mn><mo>±</mo><mn>6.8</mn><mo>±</mo><mn>0.5</mn><mo stretchy="false">)</mo><mo>%</mo></mrow></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>A</mi></mrow><mrow><mi>C</mi><mi>P</mi></mrow></msub><mo stretchy="false">(</mo><msubsup><mrow><mi mathvariant="normal">Λ</mi></mrow><mrow><mi>c</mi></mrow><mrow><mo>+</mo></mrow></msubsup><mo stretchy="false">→</mo><mrow><mi>p</mi><msup><mrow><mi>K</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>K</mi></mrow><mrow><mo>−</mo></mrow></msup></mrow><mo stretchy="false">)</mo><mo>=</mo><mo stretchy="false">(</mo><mn>3.9</mn><mo>±</mo><mn>1.7</mn><mo>±</mo><mn>0.7</mn><mo stretchy="false">)</mo><mo>%</mo></mrow></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>A</mi></mrow><mrow><mi>C</mi><mi>P</mi></mrow></msub><mo stretchy="false">(</mo><msubsup><mrow><mi mathvariant="normal">Λ</mi></mrow><mrow><mi>c</mi></mrow><mrow><mo>+</mo></mrow></msubsup><mo stretchy="false">→</mo><mspace linebreak="goodbreak"></mspace><mrow><mi>p</mi><msup><mrow><mi>π</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>π</mi></mrow><mrow><mo>−</mo></mrow></msup></mrow><mo stretchy="false">)</mo><mo>=</mo><mo stretchy="false">(</mo><mn>0.3</mn><mo>±</mo><mn>1.0</mn><mo>±</mo><mn>0.2</mn><mo stretchy="false">)</mo><mo>%</mo></mrow></math>, where the first uncertainties are statistical and the second systematic, agree with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><mi>P</mi></math> symmetry. From these results we derive the sums <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>A</mi></mrow><mrow><mi>C</mi><mi>P</mi></mrow></msub><mo stretchy="false">(</mo><msubsup><mrow><mi mathvariant="normal">Ξ</mi></mrow><mrow><mi>c</mi></mrow><mrow><mo>+</mo></mrow></msubsup><mo stretchy="false">→</mo><mrow><msup><mrow><mi mathvariant="normal">Σ</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>π</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>π</mi></mrow><mrow><mo>−</mo></mrow></msup></mrow><mo stretchy="false">)</mo><mo>+</mo><mspace linebreak="goodbreak"></mspace><msub><mrow><mi>A</mi></mrow><mrow><mi>C</mi><mi>P</mi></mrow></msub><mo stretchy="false">(</mo><msubsup><mrow><mi mathvariant="normal">Λ</mi></mrow><mrow><mi>c</mi></mrow><mrow><mo>+</mo></mrow></msubsup><mo stretchy="false">→</mo><mrow><mi>p</mi><msup><mrow><mi>K</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>K</mi></mrow><mrow><mo>−</mo></mrow></msup></mrow><mo stretchy="false">)</mo><mo>=</mo><mo stretchy="false">(</mo><mn>13.4</mn><mo>±</mo><mn>7.0</mn><mo>±</mo><mn>0.9</mn><mo stretchy="false">)</mo><mo>%</mo></mrow></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>A</mi></mrow><mrow><mi>C</mi><mi>P</mi></mrow></msub><mo stretchy="false">(</mo><msubsup><mrow><mi mathvariant="normal">Ξ</mi></mrow><mrow><mi>c</mi></mrow><mrow><mo>+</mo></mrow></msubsup><mo stretchy="false">→</mo><mrow><msup><mrow><mi mathvariant="normal">Σ</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>K</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>K</mi></mrow><mrow><mo>−</mo></mrow></msup></mrow><mo stretchy="false">)</mo><mo>+</mo><msub><mrow><mi>A</mi></mrow><mrow><mi>C</mi><mi>P</mi></mrow></msub><mo stretchy="false">(</mo><msubsup><mrow><mi mathvariant="normal">Λ</mi></mrow><mrow><mi>c</mi></mrow><mrow><mo>+</mo></mrow></msubsup><mo stretchy="false">→</mo><mrow><mi>p</mi><msup><mrow><mi>π</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>π</mi></mrow><mrow><mo>−</mo></mrow></msup></mrow><mo stretchy="false">)</mo><mo>=</mo><mo stretchy="false">(</mo><mn>4.0</mn><mo>±</mo><mspace linebreak="goodbreak"></mspace><mn>6.6</mn><mo>±</mo><mn>0.7</mn><mo stretchy="false">)</mo><mo>%</mo></mrow></math>, which are consistent with the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>U</mi></math>-spin symmetry prediction of zero. These are the first measurements of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><mi>P</mi></math> asymmetries for individual hadronic three-body charmed-baryon decays.</p>

M. Abumusabh

I. Adachi

H. Ahmed

Y. Ahn

H. Aihara

N. Akopov

S. Alghamdi

M. Alhakami

N. Althubiti

K. Amos

N. Anh Ky

D.M. Asner

H. Atmacan

R. Ayad

V. Babu

N.K. Baghel

S. Bahinipati

P. Bambade

Sw. Banerjee

M. Bartl

J. Baudot

A. Beaubien

J. Becker

J.V. Bennett

V. Bertacchi

M. Bertemes

E. Bertholet

S. Bettarini

V. Bhardwaj

D. Biswas

A. Bobrov

D. Bodrov

G. Bonvicini

J. Borah

A. Boschetti

M. Bračko

P. Branchini

R.A. Briere

T.E. Browder

A. Budano

S. Bussino

Q. Campagna

M. Campajola

G. Casarosa

C. Cecchi

P. Chang

P. Cheema

L. Chen

B.G. Cheon

C. Cheshta

H. Chetri

K. Chilikin

J. Chin

K. Chirapatpimol

H.E. Cho

K. Cho

S.J. Cho

S.K. Choi

S. Choudhury

S. Chutia

J.A. Colorado-Caicedo

I. Consigny

L. Corona

J.X. Cui

S. Das

S.A. De La Motte

G. De Nardo

G. De Pietro

R. de Sangro

M. Destefanis

A. Di Canto

Z. Doležal

I. Domínguez Jiménez

T.V. Dong

X. Dong

M. Dorigo

G. Dujany

P. Ecker

D. Epifanov

J. Eppelt

R. Farkas

P. Feichtinger

T. Ferber

T. Fillinger

G. Finocchiaro

F. Forti

B.G. Fulsom

A. Gabrielli

E. Ganiev

R. Garg

G. Gaudino

V. Gaur

V. Gautam

A. Gaz

A. Gellrich

D. Ghosh

H. Ghumaryan

R. Giordano

A. Giri

P. Gironella Gironell

Search for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><mi>P</mi></math> violation in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msubsup><mrow><mi mathvariant="normal">Ξ</mi></mrow><mrow><mi>c</mi></mrow><mrow><mo>+</mo></mrow></msubsup><mo stretchy="false">→</mo><msup><mrow><mi mathvariant="normal">Σ</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>h</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>h</mi></mrow><mrow><mo>−</mo></mrow></msup></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msubsup><mrow><mi mathvariant="normal">Λ</mi></mrow><mrow><mi>c</mi></mrow><mrow><mo>+</mo></mrow></msubsup><mo stretchy="false">→</mo><mi>p</mi><msup><mrow><mi>h</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>h</mi></mrow><mrow><mo>−</mo></mrow></msup></mrow></math> at Belle II

<p>Using data samples of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>988.4</mn><mtext> </mtext><mtext> </mtext><msup><mi>fb</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>427.9</mn><mtext> </mtext><mtext> </mtext><msup><mi>fb</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math> collected with the Belle and Belle II detectors, we present a study of the singly Cabibbo-suppressed decays <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Ξ</mi><mi>c</mi><mn>0</mn></msubsup><mo stretchy="false">→</mo><mi mathvariant="normal">Λ</mi><mi>η</mi></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Λ</mi><msup><mi>η</mi><mo>′</mo></msup></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Λ</mi><msup><mi>π</mi><mn>0</mn></msup></math>. We observe the decay <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Ξ</mi><mi>c</mi><mn>0</mn></msubsup><mo stretchy="false">→</mo><mi mathvariant="normal">Λ</mi><mi>η</mi></math> and find evidence for the decay <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Ξ</mi><mi>c</mi><mn>0</mn></msubsup><mo stretchy="false">→</mo><mi mathvariant="normal">Λ</mi><msup><mi>η</mi><mo>′</mo></msup></math>, with corresponding branching ratios determined to be <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="script">B</mi><mo stretchy="false">(</mo><msubsup><mi mathvariant="normal">Ξ</mi><mi>c</mi><mn>0</mn></msubsup><mo stretchy="false">→</mo><mi mathvariant="normal">Λ</mi><mi>η</mi><mo stretchy="false">)</mo></mrow><mo>/</mo><mrow><mi mathvariant="script">B</mi><mo stretchy="false">(</mo><msubsup><mi mathvariant="normal">Ξ</mi><mi>c</mi><mn>0</mn></msubsup><mo stretchy="false">→</mo><msup><mi mathvariant="normal">Ξ</mi><mo>−</mo></msup><msup><mi>π</mi><mo>+</mo></msup><mo stretchy="false">)</mo></mrow><mo>=</mo><mo stretchy="false">(</mo><mn>4.16</mn><mo>±</mo><mn>0.91</mn><mo>±</mo><mn>0.23</mn><mo stretchy="false">)</mo><mo>%</mo></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="script">B</mi><mo stretchy="false">(</mo><msubsup><mi mathvariant="normal">Ξ</mi><mi>c</mi><mn>0</mn></msubsup><mo stretchy="false">→</mo><mi mathvariant="normal">Λ</mi><msup><mi>η</mi><mo>′</mo></msup><mo stretchy="false">)</mo></mrow><mo>/</mo><mrow><mi mathvariant="script">B</mi><mo stretchy="false">(</mo><msubsup><mi mathvariant="normal">Ξ</mi><mi>c</mi><mn>0</mn></msubsup><mo stretchy="false">→</mo><msup><mi mathvariant="normal">Ξ</mi><mo>−</mo></msup><msup><mi>π</mi><mo>+</mo></msup><mo stretchy="false">)</mo></mrow><mo>=</mo><mspace linebreak="goodbreak"></mspace><mo stretchy="false">(</mo><mn>2.48</mn><mo>±</mo><mn>0.82</mn><mo>±</mo><mn>0.12</mn><mo stretchy="false">)</mo><mo>%</mo></math>, respectively. We find no significant signal in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Ξ</mi><mi>c</mi><mn>0</mn></msubsup><mo stretchy="false">→</mo><mi mathvariant="normal">Λ</mi><msup><mi>π</mi><mn>0</mn></msup></math> decay mode and set an upper limit at the 90% credibility level of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="script">B</mi><mo stretchy="false">(</mo><msubsup><mi mathvariant="normal">Ξ</mi><mi>c</mi><mn>0</mn></msubsup><mo stretchy="false">→</mo><mi mathvariant="normal">Λ</mi><msup><mi>π</mi><mn>0</mn></msup><mo stretchy="false">)</mo></mrow><mo>/</mo><mrow><mi mathvariant="script">B</mi><mo stretchy="false">(</mo><msubsup><mi mathvariant="normal">Ξ</mi><mi>c</mi><mn>0</mn></msubsup><mo stretchy="false">→</mo><msup><mi mathvariant="normal">Ξ</mi><mo>−</mo></msup><msup><mi>π</mi><mo>+</mo></msup><mo stretchy="false">)</mo></mrow><mo>&lt;</mo><mrow><mn>3.5</mn><mo>%</mo></mrow></math>. Multiplying these ratios by the world-average branching fraction of the normalization channel, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">B</mi><mo stretchy="false">(</mo><msubsup><mi mathvariant="normal">Ξ</mi><mi>c</mi><mn>0</mn></msubsup><mo stretchy="false">→</mo><msup><mi mathvariant="normal">Ξ</mi><mo>−</mo></msup><msup><mi>π</mi><mo>+</mo></msup><mo stretchy="false">)</mo><mo>=</mo><mo stretchy="false">(</mo><mn>1.43</mn><mo>±</mo><mn>0.27</mn><mo stretchy="false">)</mo><mo>%</mo></math>, we obtain the absolute branching fractions of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">B</mi><mo stretchy="false">(</mo><msubsup><mi mathvariant="normal">Ξ</mi><mi>c</mi><mn>0</mn></msubsup><mo stretchy="false">→</mo><mi mathvariant="normal">Λ</mi><mi>η</mi><mo stretchy="false">)</mo><mo>=</mo><mspace linebreak="goodbreak"></mspace><mo stretchy="false">(</mo><mn>5.95</mn><mo>±</mo><mn>1.30</mn><mo>±</mo><mn>0.32</mn><mo>±</mo><mn>1.13</mn><mo stretchy="false">)</mo><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>4</mn></mrow></msup></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">B</mi><mo stretchy="false">(</mo><msubsup><mi mathvariant="normal">Ξ</mi><mi>c</mi><mn>0</mn></msubsup><mo stretchy="false">→</mo><mi mathvariant="normal">Λ</mi><msup><mi>η</mi><mo>′</mo></msup><mo stretchy="false">)</mo><mo>=</mo><mo stretchy="false">(</mo><mn>3.55</mn><mo>±</mo><mn>1.17</mn><mo>±</mo><mn>0.17</mn><mo>±</mo><mn>0.68</mn><mo stretchy="false">)</mo><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>4</mn></mrow></msup></math>, and an upper limit at the 90% credibility level on the absolute branching fraction of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">B</mi><mo stretchy="false">(</mo><msubsup><mi mathvariant="normal">Ξ</mi><mi>c</mi><mn>0</mn></msubsup><mo stretchy="false">→</mo><mi mathvariant="normal">Λ</mi><msup><mi>π</mi><mn>0</mn></msup><mo stretchy="false">)</mo><mo>&lt;</mo><mn>5.2</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>4</mn></mrow></msup></math>. The quoted first and second uncertainties are statistical and systematic, respectively, while the third uncertainties arise from the branching fraction of the normalization mode. These results are consistent with most theoretical predictions and further the understanding of the underlying decay mechanisms.</p>

L. Aggarwal

A. Aloisio

C. Antonioli

T. Aushev

F.U. Bernlochner

M. Bessner

F. Bianchi

A. Bozek

E. De La Cruz-Burelo

C. Finck

G. Ghevondyan

First measurements of the branching fractions for the decay modes <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Ξ</mi><mi>c</mi><mn>0</mn></msubsup><mo stretchy="false">→</mo><mi mathvariant="normal">Λ</mi><mi>η</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Ξ</mi><mi>c</mi><mn>0</mn></msubsup><mo stretchy="false">→</mo><mi mathvariant="normal">Λ</mi><msup><mi>η</mi><mo>′</mo></msup></math> and search for the decay <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Ξ</mi><mi>c</mi><mn>0</mn></msubsup><mo stretchy="false">→</mo><mi mathvariant="normal">Λ</mi><msup><mi>π</mi><mn>0</mn></msup></math> using Belle and Belle II data

This paper presents the expected sensitivity to the neutrino oscillation parameters of the Hyper-Kamiokande long-baseline program. The Hyper-Kamiokande experiment, currently under construction in Japan, will measure the oscillations of accelerator-produced neutrinos with thousands of selected events per sample: this corresponds to an increase of statistics of a factor 25–100 with respect to recent results from the currently-running long-baseline neutrino oscillation experiment in Japan, T2K. In the most favorable scenario we will achieve the discovery of Charge-Parity (CP) violation in neutrino oscillation at $$5\sigma $$ C.L. in less than 3 years. With 10 years of data-taking, and assuming a neutrino : antineutrino beam running ratio of 1:3, a CP violation discovery at $$5\sigma $$ C.L. is possible for more than 60% of the actual values of the CP-violating phase, $$\delta _{CP}.$$ Moreover, we will measure $$\delta _{CP}$$ with a precision ranging from 20 $$^{\circ },$$ in the case of maximal CP violation, to 6 $$^{\circ },$$ in the case of CP conservation. We aim to achieve a 0.5% resolution on the $$\Delta m^2_{32}$$ parameter, and a resolution between 3% and 0.5% on the $$\sin ^2\theta _{23}$$ parameter, depending on its true value. These results are obtained by extending the analysis methods of T2K with dedicated tuning to take into account the Hyper-Kamiokande design: the larger far detector, the more powerful beam, the upgraded near detector ND280, and the planned additional Intermediate Water Cherenkov Detector.

Japan

K. Abe

M. Afif

Morocco

R. Ahl Laamara

Canada

A. Ajmi

R. Akutsu

United Kingdom

H. Alarakia-Charles

I. Alekseev

Y. Alj Hakim

Switzerland

S. Alonso Monsalve

Italy

E. Amato

F. Ameli

L. Anthony

A. Araya

Brazil

A. Arguello Quiroga

S. Arimoto

Y. Asaoka

Y. Ashida

Ukraine

V. Aushev

Spain

F. Ballester Merelo

M. Barbi

G. Barr

Poland

M. Batkiewicz-Kwasniak

France

A. Beauchêne

D. Benchekroun

V. Berardi

E. Bernardini

L. Berns

S. Bhadra

N. Bhuiyan

United States

J. Bian

D. Bianco

A. Blanchet

A. Blondel

P. Boistier

S. Bolognesi

L. Bonavera

José Bonilla

S. Bordoni

India

D. Bose

S. Boyd

C. Bozza

A. Bravar

C. Bronner

A. Bubak

A. Buchowicz

M. Buizza Avanzini

G. Burton

F. Cafagna

N. Calabria

J. Calvo Mozota

Sensitivity of the Hyper-Kamiokande experiment to neutrino oscillation parameters using accelerator neutrinos