The collinear and transverse-momentum-dependent jet fragmentation function and the radial profile for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>B</mi><mo>±</mo></msup></math> mesons in jets are measured. The <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>B</mi><mo>±</mo></msup></math> mesons are reconstructed through the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>J</mi><mo>/</mo><mi>ψ</mi></mrow><mo stretchy="false">(</mo><mo stretchy="false">→</mo><msup><mi>μ</mi><mo>+</mo></msup><msup><mi>μ</mi><mo>−</mo></msup><mo stretchy="false">)</mo><msup><mi>K</mi><mo>±</mo></msup></math> decay channel using proton-proton collision data collected during 2016–2018 with the LHCb detector at a center-of-mass (c.m.) energy of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msqrt><mi>s</mi></msqrt><mo>=</mo><mn>13</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi></math>, corresponding to an integrated luminosity of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>5.4</mn><mtext> </mtext><mtext> </mtext><msup><mi>fb</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math>. The results complement recent measurements of jet fragmentation functions for heavy-flavor hadrons and suggest a growing contribution of gluon fragmentation to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>B</mi><mo>±</mo></msup></math> mesons as the jet transverse momentum increases.

Netherlands

R. Aaij

United Kingdom

A.S.W. Abdelmotteleb

Switzerland

C. Abellan Beteta

F. Abudinén

T. Ackernley

United States

A.A. Adefisoye

Spain

B. Adeva

M. Adinolfi

P. Adlarson

France

C. Agapopoulou

C.A. Aidala

Z. Ajaltouni

S. Akar

K. Akiba

Italy

P. Albicocco

Germany

J. Albrecht

R. Aleksiejunas

CERN

F. Alessio

P. Alvarez Cartelle

R. Amalric

Brazil

S. Amato

J.L. Amey

Y. Amhis

China

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

M. Arias

L. Arnone

A. Artamonov

M. Artuso

E. Aslanides

R. Ataíde Da Silva

M. Atzeni

B. Audurier

J.A. Authier

D. Bacher

I. Bachiller Perea

S. Bachmann

M. Bachmayer

J.J. Back

Z.B. Bai

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

I.R. Barbosa

R.J. Barlow

M. Barnyakov

S. Barsuk

W. Barter

J. Bartz

Poland

S. Bashir

B. Batsukh

P.B. Battista

A. Bavarchee

A. Bay

A. Beck

M. Becker

F. Bedeschi

I.B. Bediaga

N.A. Behling

S. Belin

A. Bellavista

K. Belous

I. Belov

I. Belyaev

G. Benane

G. Bencivenni

E. Ben-Haim

A. Berezhnoy

R. Bernet

A. Bertolin

F. Betti

J. Bex

O. Bezshyyko

S. Bhattacharya

M.S. Bieker

N.V. Biesuz

A. Biolchini

M. Birch

F.C.R. Bishop

A. Bitadze

A. Bizzeti

T. Blake

<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi></math>-jet fragmentation with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>B</mi><mo>±</mo></msup><mo stretchy="false">→</mo><mi>J</mi><mo>/</mo><mi>ψ</mi><msup><mi>K</mi><mo>±</mo></msup></math> decays in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msqrt><mi>s</mi></msqrt><mo>=</mo><mn>13</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi></math> <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>p</mi><mi>p</mi></math> collisions at LHCb

We study the quantum field theory of zero-temperature perfect fluids. Such systems are defined by quantizing a classical field theory of scalar fields <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>ϕ</mi></mrow><mrow><mi>I</mi></mrow></msup></mrow></math> that act as Lagrange coordinates on an internal spatial manifold of fluid configurations. Invariance under volume-preserving diffeomorphisms acting on these scalars implies that the long-wavelength spectrum contains vortex (transverse modes) with an exact <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>ω</mi><mi>T</mi></msub><mo>=</mo><mn>0</mn></math> dispersion relation. As a consequence, physically interpreting the results obtained via perturbative quantization of this theory has proven to be challenging. In this paper, we show that correlators evaluated in a class of semiclassical (Gaussian) initial states prepared at <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>t</mi><mo>=</mo><mn>0</mn></math> are well defined and accessible via perturbation theory. The width of the initial state effectively acts as an infrared regulator without explicitly breaking diffeomorphism invariance of the classical action. As an application, we compute the stress tensor two-point correlators and show that vortex modes give a nontrivial contribution to the response function, nonlocal in both space and time.

Walter D. Goldberger

Montenegro

Petar Tadić

Quantum dynamics of perfect fluids

New threshold measurements for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>γ</mi><mi>p</mi><mo stretchy="false">→</mo><mi>p</mi><mi>J</mi><mo>/</mo><mi>ψ</mi><mo stretchy="false">→</mo><mi>p</mi><mo stretchy="false">(</mo><msup><mrow><mi>μ</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>μ</mi></mrow><mrow><mo>−</mo></mrow></msup><mo stretchy="false">)</mo></mrow></math> by 007 and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>γ</mi></mrow><mrow><mo>*</mo></mrow></msup><mi>p</mi><mo stretchy="false">→</mo><mi>p</mi><mi>J</mi><mo>/</mo><mi>ψ</mi><mo stretchy="false">→</mo><mi>p</mi><mo stretchy="false">(</mo><msup><mrow><mi>e</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>e</mi></mrow><mrow><mo>−</mo></mrow></msup><mo stretchy="false">)</mo></mrow></math> by CLAS12 allow us to extend the previous phenomenological determination of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">J</mi><mo>/</mo><mi>ψ</mi></math>-proton scattering length, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>α</mi><mrow><mi>J</mi><mo>/</mo><mi>ψ</mi><mi>p</mi></mrow></msub></math>, using GlueX threshold data for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>γ</mi><mi>p</mi><mo stretchy="false">→</mo><mi>p</mi><mi>J</mi><mo>/</mo><mi>ψ</mi><mo stretchy="false">→</mo><mi>p</mi><mo stretchy="false">(</mo><msup><mi>e</mi><mo>+</mo></msup><msup><mi>e</mi><mo>−</mo></msup><mo stretchy="false">)</mo></math>. The agreement between all three <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">J</mi><mo>/</mo><mi>ψ</mi></math> datasets shows no indication of systematic differences between methodologies. Furthermore, perturbative QCD predictions support the phenomenological determination of heavy vector meson-nucleon scattering lengths. The role of the nucleon form factor, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>F</mi><mi>N</mi></msub></math>, is discussed, and a possible correction to the phenomenological scattering length for heavy vector meson photoproduction is calculated using the pole form of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>F</mi><mi>N</mi></msub></math>. Upcoming J-PARC threshold measurements of the reaction <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>π</mi></mrow><mrow><mo>−</mo></mrow></msup><mtext> </mtext><mi>p</mi><mo stretchy="false">→</mo><mi>n</mi><mi>J</mi><mo>/</mo><mi>ψ</mi><mo stretchy="false">→</mo><mi>n</mi><mo stretchy="false">(</mo><msup><mrow><mi>l</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>l</mi></mrow><mrow><mo>−</mo></mrow></msup><mo stretchy="false">)</mo></mrow></math> will help to evaluate the possible role of heavy pentaquark, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>P</mi><mi>c</mi></msub></math>, states in low-energy <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>J</mi><mo>/</mo><mi>ψ</mi></math> production and the effects caused by the nucleon form factors.

Igor I. Strakovsky

William J. Briscoe

South Korea

Jung Keun Ahn

Russia

Misha G. Ryskin

Axel Schmidt

JLab and J-PARC measurements for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>J</mi><mo>/</mo><mi>ψ</mi></mrow></math> production at threshold

We investigate two different definitions of a scalar field effective potential in quantum field theory in de Sitter spacetime: the standard textbook definition, and the constraint effective potential proposed by O’Raifeartaigh et al. in 1986. While these definitions are equivalent in Minkowski spacetime, they differ significantly in de Sitter spacetime. We demonstrate this by computing them both explicitly at one-loop order in perturbation theory. It is well known that the perturbative expansion of the standard effective potential fails to converge for light fields. In contrast, the constraint effective potential does not suffer from this infrared problem, and it can therefore be computed using perturbation theory. We discuss the physical interpretation of the two effective potentials. In particular, we provide evidence supporting an earlier conjecture that the constraint effective potential is the correct one to use in the stochastic Starobinsky-Yokoyama theory.

Lucas Vicente García-Consuegra

Arttu Rajantie

Scalar effective potentials in de Sitter spacetime

A system of classical interacting spins can develop collective instabilities, which, in the nonlinear regime, mimic the motion of a gyroscopic pendulum. Known as the flavor pendulum, this behavior appears among the collective modes of a dense neutrino plasma after a strong reduction of phase space through symmetry assumptions. It has been identified in homogeneous slow and fast flavor systems and, most recently, in single-wave solutions of the fast system. For the first time, we explain the reasons for its ubiquitous appearance. We show that a system of three classical spins must always be pendular, or only two in the presence of an external field. Furthermore, such a system always defines a continuum of vectors with time-independent length. If these are identified as interacting spins, they immediately lead to the continuum cases of slow and fast flavor pendula. As another new insight, any of these spins can be chosen as the pendulum, periodically exchanging flavor with the rest of the system.

Damiano F.G. Fiorillo

Georg G. Raffelt

Ubiquitous flavor pendulum

We study the localization properties of the low-lying Dirac eigenmodes in QCD near the crossover temperature, using stout-smeared staggered fermions and Symanzik-improved gauge action on the lattice. On <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>N</mi><mi mathvariant="normal">t</mi></msub><mo>=</mo><mn>8</mn></math> lattices we find that localized low modes, absent at low temperature, appear at a temperature <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>T</mi><mi>loc</mi></msub></math> in the range <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>150</mn><mtext> </mtext><mtext> </mtext><mi>MeV</mi><mo>≤</mo><msub><mi>T</mi><mi>loc</mi></msub><mo>≤</mo><mn>160</mn><mtext> </mtext><mtext> </mtext><mi>MeV</mi></math>, well within the chiral crossover range as determined from the chiral condensate and from the light-quark susceptibility. Since with our choice of lattice action neither the chiral transition region nor the renormalized mobility edges change significantly above <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>N</mi><mi mathvariant="normal">t</mi></msub><mo>=</mo><mn>8</mn></math>, our conclusion that <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>T</mi><mi>loc</mi></msub></math> is in the chiral crossover region is expected to remain valid in the continuum limit.

Hungary

Matteo Giordano

Tamás G. Kovács

Cyprus

Ferenc Pittler

Dirac mode localization in QCD near the crossover temperature

We extensively explore the connections between timelike entanglement and non-Hermitian density matrices in quantum many-body systems. We classify setups where we encounter non-Hermitian density matrices into two types: one is due to causal influences under unitary evolutions, and the other is due to nonunitary evolutions in non-Hermitian systems. We provide various examples of these setups including interacting harmonic oscillators, two dimensional conformal field theories, and holographic dualities. In them, we compute the timelike entanglement entropy and imagitivity, which measures how much density matrices are non-Hermitian. In both two classes, typical holographic examples are given by traversable AdS wormholes. We explain how causal influences in a wormhole dual to a pair of non-Hermitian quantum systems is possible even without interactions between them. We argue that to realize a traversable wormhole we need not only ordinary quantum entanglement but also timelike entanglement.

Japan

Jonathan Harper

Taishi Kawamoto

Ryota Maeda

Nanami Nakamura

Tadashi Takayanagi

Non-Hermitian density matrices from timelike entanglement and wormholes

Low-threshold dark matter detectors, in particular cryogenic detectors based on dielectric materials, are among the best tools for probing sub-GeV dark matter masses. In the coming years, detectors of this type will become sensitive to solar neutrino scattering. Previous work has shown that, for dark matter scattering at very low recoil energies, one must include collective excitations of the electrons in the solid. In this work, we have computed the collective excitations due to neutrino scattering on electrons and nuclei. We find the full electron-scattering response at leading order is captured by five structure factors and identify the leading component with the electron energy-loss function. Then, using silicon and germanium detectors as an example, we perform a dark matter sensitivity study and compute their respective neutrino floors—taking the electronic structure into account for all dark matter and neutrino scattering channels. Lastly, we show that these detectors are sensitive to unexplored scenarios of beyond-Standard Model neutrino physics, within the exposure required to reach the neutrino floor.

James B. Dent

Barry A. Friedman

Australia

Jayden L. Newstead

Subir Sabharwal

Nuclear and electron scattering by neutrinos and dark matter in condensed systems

We present a comprehensive study of the two-flavor quark-meson-diquark (QMD) model by comparing a renormalization approach with a renormalization-group (RG) consistent mean-field formulation based on the functional renormalization group (FRG). The renormalized QMD model allows analytical investigations of key quantities such as the zero-temperature diquark gap and the critical temperature for color superconductivity, ultimately reproducing the exact BCS relation in the high-density limit. We carry out the same analysis for different schemes of RG-consistent QMD models. We show that the RG-consistent approach yields a phase diagram and thermodynamic properties qualitatively similar to those of the renormalized model, provided both are embedded within a unified scheme that ensures consistent vacuum properties. In particular, both treatments recover the Stefan-Boltzmann limit at high densities. On the other hand, whether the BCS relation for the critical temperature is satisfied depends on the details of the RG-consistent setup. Our results highlight the relevance of renormalization and RG-consistent methods for accurately capturing the thermodynamics of QMD and related effective models with diquark degrees of freedom.

Hosein Gholami

Lennart Kurth

Ugo Mire

Michael Buballa

Bernd-Jochen Schaefer

Renormalizing the quark-meson-diquark model

We investigate the production of hyperons, charmed baryons, and potential hadronic molecular states in neutrino-proton (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mover accent="true"><mi>ν</mi><mo stretchy="false">¯</mo></mover><mi>μ</mi></msub><mi>p</mi></math>) reaction, a process characterized by a particularly clean final state. Employing effective Lagrangians, chiral perturbation theory, and a hadronic molecular model, we perform theoretical calculations for several relevant channels, including those leading to the formation of the hadronic molecular candidate <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">(</mo><mover accent="true"><mi>D</mi><mo stretchy="false">¯</mo></mover><mi>N</mi><mo stretchy="false">)</mo></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">(</mo><mover accent="true"><mi>D</mi><mo stretchy="false">¯</mo></mover><mi mathvariant="normal">Σ</mi><mo stretchy="false">)</mo></math>. Our results indicate that future neutrino facilities could serve as a complementary platform for exploring exotic baryonic states and provide valuable insights into the dynamics of strong interactions in the strange and charm sectors.

Kai-Sa Qiao

Bing-Song Zou

Production of hyperons, charmed baryons, and hadronic molecule candidates in neutrino-proton reaction