We introduce a novel approach that utilizes neutrino events from the off-axis near detector to investigate the beam profile in long-baseline neutrino experiments. Understanding the dynamics of the neutrino beam is crucial for improving the precision of neutrino oscillation measurements. We demonstrate that certain observables related to the azimuthal angle of the neutrino direction are useful for determining the average neutrino production point from experimental data, providing a valuable cross-check against Monte Carlo simulations. Additionally, these observables can help identify potential alignment issues between the detector and the decay volume. In future neutrino experiments with significantly higher statistics, these observables will become essential to ensure the accuracy and stability of the beam profile.

Switzerland

S. Karpova

F. Sánchez

D. Douqa

Characterizing beam profiles in accelerator neutrino experiments through off-axis neutrino interactions

We investigate a type of dynamical chiral symmetry breaking (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="normal">D</mi><mi>χ</mi><mi>SB</mi></mrow></math>) for various current quark masses using the interacting instanton liquid model. The type of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">D</mi><mi>χ</mi><mi>SB</mi></math> is classified based on the sign of the second derivative of the free energy density with respect to the quark condensate at the origin. We perform numerical simulations of the interacting instanton liquid model with the flavor SU(2) symmetric and (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>2</mn><mo>+</mo><mn>1</mn></mrow></math>)-flavor quarks. We find that the curvature is negative in the SU(2) case. This means the ordinary type of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">D</mi><mi>χ</mi><mi>SB</mi></math>. In contrast, in the (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>2</mn><mo>+</mo><mn>1</mn></mrow></math>)-flavor case, a positive curvature is observed when the strange quark mass is as small as those of the up and down quarks. This suggests that the anomaly-driven type of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">D</mi><mi>χ</mi><mi>SB</mi></math> can occur under the approximate flavor SU(3) symmetry. As the strange quark mass increases, the curvature gradually decreases and becomes negative when the strange quark mass is approximately three times larger than those of the light quarks. This difference can be understood in terms of the ’t Hooft vertex which induces a six-quark interaction in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>N</mi><mi>f</mi></msub><mo>=</mo><mn>3</mn></math> case and does a four-quark interaction in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>N</mi><mi>f</mi></msub><mo>=</mo><mn>2</mn></math> case. Our results might indicate that the ratio between the strange and light quark masses plays a crucial role in understanding the microscopic relationship between <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">D</mi><mi>χ</mi><mi>SB</mi></math> and the anomaly effect.

Japan

Yamato Suda

Daisuke Jido

Different scenarios of dynamical chiral symmetry breaking in the interacting instanton liquid model via flavor symmetry breaking

Mesons’ internal structure and dynamics may be accessed through hard exclusive electroproduction processes such as deeply virtual Compton scattering in both near forward and near backward kinematics. With the help of the Sullivan process, which allows us to use a nucleon target as a quasireal <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>π</mi></math> meson emitter, we study backward scattering in the framework of collinear QCD factorization where pion-to-photon transition distribution amplitudes describe the photon content of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>π</mi></math> meson. We present a model of these transition distribution amplitudes based on the overlap of light-front wave functions primarily developed for generalized parton distributions, using a previously computed pion light-front wave function and deriving a new model for the light-front wave functions of the photon. This leads us to an estimate of the cross sections for JLab energies. We conclude that deeply virtual <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>e</mi><mi>p</mi><mo stretchy="false">→</mo><mi>e</mi><mi>γ</mi><mi>M</mi><mi>n</mi></math> processes, in backward kinematics, may be experimentally discovered in the near future.

France

Abigail R. Castro

Cédric Mezrag

Spain

Jose M. Morgado Chávez

Bernard Pire

Backward DVCS in a Sullivan process

The quantum speed limits (QSLs) set fundamental lower bounds on the time required for a quantum system to evolve from a given initial state to a final state. In this work, we investigate <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><mi>P</mi></math> violation and the mass ordering problem of neutrino oscillations in matter using the QSL time as a key analytical tool. We examine the QSL time for the unitary evolution of two- and three-flavor neutrino states, both in vacuum and in the presence of matter. Two-flavor neutrino oscillations are used as a precursor to their three-flavor counterparts. We further compute the QSL time for neutrino state evolution and entanglement in terms of neutrino survival and oscillation probabilities, which are experimentally measurable quantities in neutrino experiments. A difference in the QSL time between the normal and inverted mass ordering scenarios, for neutrino state evolution as well as for entanglement, under the effect of a <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><mi>P</mi></math> violation phase is observed. Our results are illustrated using the length scales and energies of ongoing long-baseline accelerator neutrino experiments such as T2K, NOvA, and the upcoming DUNE experiment. Notably, three-flavor neutrino oscillations in constant matter density exhibit faster state evolution across all these neutrino experiments in the normal mass ordering scenario. Additionally, we observe fast entanglement suppression in DUNE assuming a normal mass ordering.

India

Subhadip Bouri

Abhishek Kumar Jha

Subhashish Banerjee

Probing <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>C</mi><mi>P</mi></math> violation and mass ordering in neutrino oscillations in matter through quantum speed limits

Based on <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 about <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>4.5</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 4599.53 and 4698.82 MeV with the BESIII detector, the absolute branching fraction of the Cabibbo-favored decay <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Λ</mi><mi>c</mi><mo>+</mo></msubsup><mo stretchy="false">→</mo><mi mathvariant="normal">Λ</mi><msubsup><mi>K</mi><mi>S</mi><mn>0</mn></msubsup><msup><mi>K</mi><mo>+</mo></msup></math> is measured to be <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">(</mo><mn>3.12</mn><mo>±</mo><mn>0.46</mn><mo>±</mo><mspace linebreak="goodbreak"></mspace><mn>0.15</mn><mo stretchy="false">)</mo><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>3</mn></mrow></msup></math>. Combined with a previous measurement from the BESIII Collaboration, the branching fraction of the decay <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Λ</mi><mi>c</mi><mo>+</mo></msubsup><mo stretchy="false">→</mo><mi mathvariant="normal">Λ</mi><msubsup><mi>K</mi><mi>S</mi><mn>0</mn></msubsup><msup><mi>K</mi><mo>+</mo></msup></math> is calculated to be <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">(</mo><mn>3.07</mn><mo>±</mo><mn>0.26</mn><mo>±</mo><mn>0.13</mn><mo stretchy="false">)</mo><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>3</mn></mrow></msup></math>. The decay <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Λ</mi><mi>c</mi><mo>+</mo></msubsup><mo stretchy="false">→</mo><msup><mi mathvariant="normal">Ξ</mi><mn>0</mn></msup><msubsup><mi>K</mi><mi>S</mi><mn>0</mn></msubsup><msup><mi>π</mi><mo>+</mo></msup></math> is observed for the first time with a statistical significance of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>6.6</mn><mi>σ</mi></math>, and its branching fraction is determined to be <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">(</mo><mn>3.70</mn><mo>±</mo><mn>0.60</mn><mo>±</mo><mn>0.21</mn><mo stretchy="false">)</mo><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>3</mn></mrow></msup></math>. In addition, a search for the decay <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Λ</mi><mi>c</mi><mo>+</mo></msubsup><mo stretchy="false">→</mo><msup><mi mathvariant="normal">Σ</mi><mn>0</mn></msup><msubsup><mi>K</mi><mi>S</mi><mn>0</mn></msubsup><msup><mi>K</mi><mo>+</mo></msup></math> is performed, and its branching fraction is determined to be <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">(</mo><mn>0.8</mn><msubsup><mn>0</mn><mrow><mo>−</mo><mn>0.24</mn></mrow><mrow><mo>+</mo><mn>0.28</mn></mrow></msubsup><mo>±</mo><mn>0.16</mn><mo stretchy="false">)</mo><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>3</mn></mrow></msup></math>, corresponding to an upper limit of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>1.28</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>3</mn></mrow></msup></math> at a 90% confidence level. These measurements provide new information that can be used to distinguish between theoretical models.

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. Chen

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

Y.B. Chen

Y.Q. Chen

Z.J. Chen

South Korea

S.K. Choi

X. Chu

G. Cibinetto

F. Cossio

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

Y.T. Feng

M. Fritsch

C.D. Fu

J.L. Fu

Y.W. Fu

Measurement of the branching fractions of the Cabibbo-favored decays <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Λ</mi><mi>c</mi><mo>+</mo></msubsup><mo stretchy="false">→</mo><mi mathvariant="normal">Λ</mi><msubsup><mi>K</mi><mi>S</mi><mn>0</mn></msubsup><msup><mi>K</mi><mo>+</mo></msup></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><msup><mrow><mi mathvariant="normal">Ξ</mi></mrow><mrow><mn>0</mn></mrow></msup><msubsup><mrow><mi>K</mi></mrow><mrow><mi>S</mi></mrow><mrow><mn>0</mn></mrow></msubsup><msup><mrow><mi>π</mi></mrow><mrow><mo>+</mo></mrow></msup></mrow></math> and search for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi mathvariant="normal">Λ</mi><mi>c</mi><mo>+</mo></msubsup><mo stretchy="false">→</mo><msup><mi mathvariant="normal">Σ</mi><mn>0</mn></msup><msubsup><mi>K</mi><mi>S</mi><mn>0</mn></msubsup><msup><mi>K</mi><mo>+</mo></msup></math>

The process of all-vortex nonlinear Compton scattering in an intense and polarized laser field, in which the initial and final electrons and the emitted <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>γ</mi></math> photon are all in vortex states, is studied theoretically. We develop a formalism for the process, which allows us to study the exchanges of the orbital angular momentum (OAM) and spin angular momentum among the electron, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>γ</mi></math> photon, and laser. A wave packet of the Bessel-Gaussian type is adopted to describe the initial vortex electron for the purpose of normalization. Both circularly and linearly polarized lasers are examined. Substantial numerical calculations are performed to reveal the physics of the exchanges of the OAM and spin angular momentum. The strong impact of the laser intensity and the opening angle of the initial vortex electron is demonstrated. Our results also suggest possible scenarios for the separation of the emitted <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>γ</mi></math> photons with different OAMs, as well as a possible way which could help to distinguish the OAM and spin of the vortex particle by the multipeak structure in the spectrum of the emitted photon.

Yi Liao

Quan-Yu Wang

Yuanbin Wu

All-vortex nonlinear Compton scattering in a polarized laser field

We investigate the influence of quark anomalous magnetic moments (AMMs) on the mass spectra of neutral pseudoscalar mesons (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>π</mi></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>K</mi></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>η</mi></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>η</mi><mo>′</mo></msup></math>) under external magnetic fields, finite temperatures, and quark chemical potentials using the three-flavor Nambu-Jona-Lasinio model. By incorporating AMMs at the quark level, we reveal that AMMs significantly alter the magnetic field dependence of constituent quark masses, inducing first-order phase transitions for light quarks at critical fields, while strange quarks exhibit nonmonotonic mass behavior. The inclusion of AMMs reshapes the QCD phase diagram, suppressing chiral transition temperatures, and the strong magnetic field shifts critical endpoints toward lower <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>μ</mi></math> and higher <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>T</mi></math> without AMMs. The crossover phase transition without AMMs is replaced by a first-order transition with AMMs under strong fields. Moreover, the inverse magnetic catalysis (IMC) induced by the introduction of AMMs qualitatively aligns with the predictions of lattice QCD (LQCD) for the dependence of phase transition temperature on the magnetic field. For mesons, a larger AMM triggers abrupt mass collapses and enhances flavor spitting at zero <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>μ</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>T</mi></math> and accelerates chiral restoration for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>K</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>η</mi></math> mesons via thresholds tied to strange quark masses in finite <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>μ</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>T</mi></math>. These findings underscore AMMs’ critical role in reconciling effective model predictions with LQCD results, particularly in reproducing IMC and explaining phase transition dynamics.

Chang-Yong Yang

Sheng-Qin Feng

Quark anomalous magnetic moments and neutral pseudoscalar meson dynamics with the three-flavor NJL model in magnetized quark matter

The scattering and absorption rates of light dark matter with electron spin-dependent interactions depend on the target’s spin response. We show how this response is encoded by the target’s dynamical magnetic susceptibility, which can be measured using neutron scattering. We directly use existing neutron scattering data to compute the dark matter scattering rate in a candidate target material, finding close agreement with the previous first-principles calculation at MeV dark matter masses. Complementary experiments and measurements can extend the reach of this technique to other dark matter models and masses, and identify promising target materials for future experiments.

Asher Berlin

Alexander J. Millar

Tanner Trickle

Kevin Zhou

Determining spin-dependent light dark matter rates from neutron scattering

We solve models of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>N</mi></mrow></math> species of fermions in the lowest Landau level with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="normal">U</mi><mo stretchy="false">(</mo><mi>N</mi><mo stretchy="false">)</mo></mrow></math>-invariant interactions in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>N</mi><mo>≫</mo><mn>1</mn></mrow></math> limit. We find saddles of the second quantized path integral at fixed chemical potential corresponding to fractional Hall states with filling <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mo stretchy="false">(</mo><mi>p</mi><mo>/</mo><mi>q</mi><mo stretchy="false">)</mo></mrow></math>, where the integers <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>p</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>q</mi></math> depend on the chemical potential and interactions. On a long torus there are <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>q</mi></math> such states related by translation symmetry, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>SU</mi><mo stretchy="false">(</mo><mi>N</mi><mo stretchy="false">)</mo></mrow></math>-invariant excitations of fractional charge. Remarkably, these saddles and their filling persist as extrema of the second-quantized action at <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>N</mi><mo>=</mo><mn>1</mn></math>. Our construction gives a first-principles derivation of fractional Hall states from strongly interacting fermions.

Canada

Kristan Jensen

Amir Raz

Fractional Hall Physics from Large <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>N</mi></mrow></math> Interacting Fermions

To better understand recent predictions on the moat regime of quantum chromodynamics (QCD) matter, this paper extends the previous work within the two-flavor quark-meson (QM) model to the more realistic <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>2</mn><mo>+</mo><mn>1</mn></math> flavor Polyakov-quark-meson (PQM) model. Mainly, two effects are further taken into account: strange quark and confinement coded through Polyakov loop. Model parameters are chosen to consistently reproduce the pseudocritical temperature from lattice QCD, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>T</mi><mi mathvariant="normal">C</mi></msub><mo>∼</mo><mn>156</mn><mtext> </mtext><mtext> </mtext><mi>MeV</mi></math>, and the baryon chemical potential at the critical end point (CEP) from functional renormalization group to QCD matter (FRG-QCD), <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>μ</mi></mrow><mrow><mi mathvariant="normal">B</mi></mrow></msub><mrow><mo stretchy="false">(</mo><mi>CEP</mi><mo stretchy="false">)</mo></mrow><mo>∼</mo><mn>635</mn><mtext> </mtext><mtext> </mtext><mi>MeV</mi></mrow></math>. It is found that the basic features of moat regimes for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>σ</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>π</mi></math> mesons remain similar to those from QM model: Moat regimes cover the region where temperature or baryon chemical potential is large; reentrances occur around the critical baryon chemical potential of chiral transition at zero temperature. Thus, the FRG-QCD results can still not be well understood, especially why the extrapolated CEP should be consistent with the boundaries of moat regimes for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>σ</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>π</mi></math> mesons. Nevertheless, some basic features can be understood qualitatively, and it is consistent that the pole energies are increasing functions of momenta in the whole <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>T</mi><mo>−</mo><msub><mi>μ</mi><mi mathvariant="normal">B</mi></msub></math> plane. The moat regime and pole energy of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>K</mi></math> mesons are also studied with the features similar.

Gaoqing Cao

Moat regimes within a (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>2</mn><mo>+</mo><mn>1</mn></mrow></math>)-flavor Polyakov-quark-meson model