We present the first lattice QCD determination of the electromagnetic form factors of the exotic tetraquark <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>T</mi></mrow><mrow><mi>b</mi><mi>b</mi></mrow></msub><mo stretchy="false">(</mo><mi>b</mi><mi>b</mi><mover accent="true"><mrow><mi>u</mi></mrow><mrow><mo stretchy="false">¯</mo></mrow></mover><mover accent="true"><mrow><mi>d</mi></mrow><mrow><mo stretchy="false">¯</mo></mrow></mover><mo stretchy="false">)</mo></mrow></math> with quantum numbers <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>I</mi><mo stretchy="false">(</mo><msup><mrow><mi>J</mi></mrow><mrow><mi>P</mi></mrow></msup><mo stretchy="false">)</mo><mo>=</mo><mn>0</mn><mo stretchy="false">(</mo><msup><mrow><mn>1</mn></mrow><mrow><mo>+</mo></mrow></msup><mo stretchy="false">)</mo></mrow></math>. The extracted form factors encode information about its internal structure, including the charge distribution and the magnetic dipole moments, determined separately for the light and heavy quarks. Our results provide evidence in favor of it being a bound state consisting of a compact heavy diquark <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">[</mo><mi>b</mi><mi>b</mi><mo stretchy="false">]</mo></math> in a color-antitriplet with spin one and a light antidiquark <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mo stretchy="false">[</mo><mover accent="true"><mrow><mi>u</mi></mrow><mrow><mo stretchy="false">¯</mo></mrow></mover><mover accent="true"><mrow><mi>d</mi></mrow><mrow><mo stretchy="false">¯</mo></mrow></mover><mo stretchy="false">]</mo></mrow></math> in a color-triplet with spin zero. The charge radius of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>T</mi><mrow><mi>b</mi><mi>b</mi></mrow></msub></math> is found to be significantly smaller than the combined charge radii of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>B</mi><mo>*</mo></msup></math> mesons. These two comprise the lowest-lying threshold <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><msup><mi>B</mi><mo>*</mo></msup></math> in the channel that we are considering, and their electric charge form factors are also determined. The computations were performed on a single ensemble, generated by the Coordinated Lattice Simulations effort, with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>N</mi></mrow><mrow><mi>f</mi></mrow></msub><mo>=</mo><mn>2</mn><mo>+</mo><mn>1</mn></mrow></math> dynamical quarks and a lattice spacing of approximately <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>a</mi><mo>≈</mo><mn>0.064</mn><mtext> </mtext><mtext> </mtext><mi>fm</mi></mrow></math> at the pion mass <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>m</mi></mrow><mrow><mi>π</mi></mrow></msub><mo>≈</mo><mn>290</mn><mtext> </mtext><mtext> </mtext><mi>MeV</mi></mrow></math>.

Ivan Vujmilovic

Sara Collins

Luka Leskovec

Sasa Prelovsek

Electromagnetic Form Factors and Structure of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>T</mi></mrow><mrow><mi>b</mi><mi>b</mi></mrow></msub></mrow></math> Tetraquark from Lattice QCD

Recent lattice QCD simulations and phenomenological models indicate that the nucleon’s gravitational form factor <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>B</mi><mi>N</mi></msub><mo stretchy="false">(</mo><mi>t</mi><mo stretchy="false">)</mo></math> remains remarkably small at finite momentum transfer <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>t</mi></math>. While <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>B</mi><mi>N</mi></msub><mo stretchy="false">(</mo><mn>0</mn><mo stretchy="false">)</mo><mo>=</mo><mn>0</mn></math> is a known consequence of the equivalence principle, the physical origin of its suppression at finite <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>t</mi></math> has not been fully elucidated. In this work, we demonstrate that the smallness of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>B</mi><mi>N</mi></msub><mo stretchy="false">(</mo><mi>t</mi><mo stretchy="false">)</mo></math> arises from a fundamental cancellation within the nucleon’s wave functions. Using light-front holographic QCD, we show that <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>B</mi><mi>N</mi></msub><mo stretchy="false">(</mo><mi>t</mi><mo stretchy="false">)</mo></math> is governed by an antisymmetric factor in the longitudinal dynamics that leads to an exact vanishing in the symmetric limit and significant suppression for realistic nucleon structures. Our results suggest that the smallness of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>B</mi><mi>N</mi></msub><mo stretchy="false">(</mo><mi>t</mi><mo stretchy="false">)</mo></math> is a signature of the nucleon’s dominant S-wave character, providing a formal justification for its frequent omission in practical applications like near-threshold <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>J</mi><mo>/</mo><mi>ψ</mi></math> production.

Xianghui Cao

Bheemsehan Gurjar

Chandan Mondal

Chen Chen

Yang Li

Origin of the nucleon gravitational form factor <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>B</mi><mi>N</mi></msub><mo stretchy="false">(</mo><mi>t</mi><mo stretchy="false">)</mo></math>: Exposition in light-front holographic QCD

We propose the “naive” <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>T</mi></math>-odd Collins-Soper moments in the Drell-Yan process as probes of previously unexplored directions in the Standard Model effective field theory (SMEFT) parameter space. We show that the moments <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>A</mi><mn>6</mn></msub></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>A</mi><mn>7</mn></msub></math> in the high invariant mass and transverse momentum region are sensitive to dimension-8 <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>C</mi><mi>P</mi></mrow></math>-odd semileptonic four-fermion operators with an additional gluon field strength tensor. Using the projected integrated luminosity of a future high-luminosity LHC, we show that effective ultraviolet scales in the few-TeV range can be probed with this process.

Frank Petriello

Kaan Şimşek

Naive <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>T</mi></math>-odd Drell-Yan angular coefficients as a probe of the dimension-8 SMEFT

The <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>T</mi></mrow></math> matrix of the heavy quark-antiquark (<math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>Q</mi><mover accent="true"><mi>Q</mi><mo>¯</mo></mover><mspace width="0.28em"></mspace></mrow></math>) pair interacting through a screened Cornell potential in the quark-gluon plasma is computed without employing the partial-wave expansion. This is compared with the results obtained using the conventional method of partial-wave expansion. Through a comprehensive survey over a range of screening mass and center-of-mass (c.m.) energy, which, when combined, determine the orbital angular momentum involved in the scattering, it is demonstrated that a substantial number of partial-wave terms are necessary to precisely match the full scattering amplitude directly obtained from the method without partial-wave expansion. For moderate screening masses (corresponding to one to two times the crossover transition temperature) and c.m. energy, the number of partial waves required for satisfactory matching turns out as large as 10–20, substantially larger than what one would expect based on simply measuring the magnitudes of the first few partial-wave amplitudes. This highlights the efficacy and advantage of the new method in directly obtaining the full scattering amplitude needed for further computation of physical observables, which is illustrated by comparing the calculations of heavy quark-antiquark scattering cross section and heavy quark drag coefficient between the two methods. We also employ the new method to calculate the <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>T</mi></mrow></math> matrix at c.m. energies below the <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>Q</mi><mover accent="true"><mi>Q</mi><mo>¯</mo></mover><mspace width="0.28em"></mspace></mrow></math>mass threshold, and demonstrate the presence of bound states of different orbital quantum numbers simultaneously in a single energy scan.

Anurag Tiwari

Min He

In-medium heavy quark-antiquark <math xmlns="http://www.w3.org/1998/Math/MathML"><mi>T</mi></math> matrix without partial-wave expansion

Inclusive and differential cross section measurements of top quark pair ( $$ \textrm{t}\overline{\textrm{t}} $$ ) production in association with a photon (γ) are performed as a function of lepton, photon, top quark, and $$ \textrm{t}\overline{\textrm{t}} $$ kinematic observables, using data from proton-proton collisions at $$ \sqrt{s}=13 $$ TeV, corresponding to an integrated luminosity of 138 fb , collected at the CERN LHC with the CMS detector. Events containing two leptons (electrons or muons) and a photon in the final state are considered. The fiducial cross section of $$ \textrm{t}\overline{\textrm{t}}\upgamma $$ is measured to be 137 ± 8 fb, in a phase space including events with a high momentum, isolated photon. The fiducial cross section of $$ \textrm{t}\overline{\textrm{t}}\upgamma $$ is also measured to be 56 ± 5 fb when considering only events where the photon is emitted in the production part of the process. Both measurements are in agreement with the theoretical predictions, of 126 ± 19 fb and 57 ± 5 fb, respectively. Differential measurements are performed at the particle and parton levels. Additionally, inclusive and differential ratios between the cross sections of $$ \textrm{t}\overline{\textrm{t}}\upgamma $$ and $$ \textrm{t}\overline{\textrm{t}} $$ production are measured. The inclusive ratio is found to be 0.0133 ± 0.0005, in agreement with the standard model prediction of 0.0127 ± 0.0008. The top quark charge asymmetry in $$ \textrm{t}\overline{\textrm{t}}\upgamma $$ production is also measured to be −0.012 ± 0.042, compatible with both the standard model prediction and with no asymmetry.

Armenia

A. Hayrapetyan

V. Makarenko

A. Tumasyan

Austria

W. Adam

J. Andrejkovic

L. Benato

T. Bergauer

M. Dragicevic

C. Giordano

P. Hussain

M. Jeitler

N. Krammer

A. Li

D. Liko

M. Matthewman

I. Mikulec

J. Schieck

D. Schwarz

R. Schöfbeck

M. Shooshtari

M. Sonawane

W. Waltenberger

C.E. Wulz

Belgium

T. Janssen

H. Kwon

D. Ocampo Henao

T. Laer

P. Mechelen

J. Bierkens

N. Breugelmans

J. D’Hondt

S. Dansana

A. Moor

M. Delcourt

F. Heyen

Y. Hong

P. Kashko

S. Lowette

I. Makarenko

D. Müller

J. Song

S. Tavernier

M. Tytgat

G. Onsem

S. Putte

D. Vannerom

B. Bilin

B. Clerbaux

A. Das

I. Bruyn

G. Lentdecker

H. Evard

L. Favart

P. Gianneios

A. Khalilzadeh

F. Khan

A. Malara

M. Shahzad

L. Thomas

M. Bemden

C. Vander Velde

P. Vanlaer

F. Zhang

M. Coen

D. Dobur

G. Gokbulut

J. Knolle

D. Marckx

K. Skovpen

A. Tomaru

N. Bossche

J. Linden

J. Vandenbroeck

L. Wezenbeek

S. Bein

A. Benecke

A. Bethani

G. Bruno

A. Cappati

J. De Favereau De Jeneret

C. Delaere

F. Gameiro Casalinho

A. Giammanco

A. Guzel

V. Lemaitre

J. Lidrych

P. Malek

P. Mastrapasqua

S. Turkcapar

Brazil

G. Alves

M. Barroso Ferreira Filho

E. Coelho

C. Hensel

T. Menezes De Oliveira

C. Mora Herrera

P. Rebello Teles

M. Soeiro

E. Tonelli Manganote

A. Vilela Pereira

W. Aldá Júnior

Inclusive and differential measurements of the $$ \textrm{t}\overline{\textrm{t}}\upgamma $$ cross section and the $$ \textrm{t}\overline{\textrm{t}}\upgamma /\textrm{t}\overline{\textrm{t}} $$ cross section ratio in proton-proton collisions at $$ \sqrt{s}=13 $$ TeV

The first four-dimensional amplitude analysis of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>B</mi><mo>+</mo></msup><mo stretchy="false">→</mo><mi>ψ</mi><mo stretchy="false">(</mo><mn>2</mn><mi>S</mi><mo stretchy="false">)</mo><msubsup><mi>K</mi><mi mathvariant="normal">S</mi><mn>0</mn></msubsup><msup><mi>π</mi><mo>+</mo></msup></math> decay is performed with proton-proton collision data collected by the LHCb experiment at <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"><mrow><mn>5.4</mn><mtext> </mtext><mtext> </mtext><mrow><mi mathvariant="normal">f</mi><msup><mrow><mi mathvariant="normal">b</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></mrow></math>. The data cannot be fully explained by <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>B</mi><mo>+</mo></msup><mo stretchy="false">→</mo><mi>ψ</mi><mo stretchy="false">(</mo><mn>2</mn><mi>S</mi><mo stretchy="false">)</mo><msup><mi>K</mi><mrow><mo>*</mo><mo>+</mo></mrow></msup></math> contributions alone. A significantly better description of the data is obtained by adding a <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>T</mi><mrow><mi>c</mi><mover accent="true"><mi>c</mi><mo stretchy="false">¯</mo></mover></mrow><mo>+</mo></msubsup></math> contribution decaying to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>ψ</mi><mo stretchy="false">(</mo><mn>2</mn><mi>S</mi><mo stretchy="false">)</mo><msup><mi>π</mi><mo>+</mo></msup></math>. The properties of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>T</mi><mrow><mi>c</mi><mover accent="true"><mi>c</mi><mo stretchy="false">¯</mo></mover></mrow><mo>+</mo></msubsup></math> structure are consistent with the exotic state <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>T</mi><mrow><mi>c</mi><mover accent="true"><mi>c</mi><mo stretchy="false">¯</mo></mover><mn>1</mn></mrow></msub><mo stretchy="false">(</mo><mn>4430</mn><msup><mo stretchy="false">)</mo><mo>+</mo></msup></math> reported in the isospin-related <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mover accent="true"><mi>B</mi><mo stretchy="false">¯</mo></mover><mn>0</mn></msup><mo stretchy="false">→</mo><mi>ψ</mi><mo stretchy="false">(</mo><mn>2</mn><mi>S</mi><mo stretchy="false">)</mo><msup><mi>K</mi><mo>−</mo></msup><msup><mi>π</mi><mo>+</mo></msup></math> decay. Effects of a possible <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>T</mi><mrow><mi>c</mi><mover accent="true"><mi>c</mi><mo stretchy="false">¯</mo></mover><mn>1</mn></mrow></msub><mo stretchy="false">(</mo><mn>4430</mn><msup><mo stretchy="false">)</mo><mo>+</mo></msup><mo stretchy="false">→</mo><msubsup><mover accent="true"><mi>D</mi><mo stretchy="false">¯</mo></mover><mn>1</mn><mo>*</mo></msubsup><mo stretchy="false">(</mo><mn>2600</mn><msup><mo stretchy="false">)</mo><mn>0</mn></msup><msup><mi>D</mi><mo>+</mo></msup></math> decay mode on the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>T</mi><mrow><mi>c</mi><mover accent="true"><mi>c</mi><mo stretchy="false">¯</mo></mover><mn>1</mn></mrow></msub><mo stretchy="false">(</mo><mn>4430</mn><msup><mo stretchy="false">)</mo><mo>+</mo></msup><mo stretchy="false">→</mo><mi>ψ</mi><mo stretchy="false">(</mo><mn>2</mn><mi>S</mi><mo stretchy="false">)</mo><msup><mi>π</mi><mo>+</mo></msup></math> mass distribution are investigated through a Flatté parametrization, providing constraints on the relative decay strength. A description of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>T</mi><mrow><mi>c</mi><mover accent="true"><mi>c</mi><mo stretchy="false">¯</mo></mover><mn>1</mn></mrow></msub><mo stretchy="false">(</mo><mn>4430</mn><msup><mo stretchy="false">)</mo><mo>+</mo></msup></math> structure using the triangle singularity mechanism is studied and also found to be consistent with the data.

R. Aaij

A.S.W. Abdelmotteleb

C. Abellan Beteta

F. Abudinén

T. Ackernley

A.A. Adefisoye

B. Adeva

M. Adinolfi

P. Adlarson

C. Agapopoulou

C.A. Aidala

Z. Ajaltouni

S. Akar

K. Akiba

M. Akthar

P. Albicocco

J. Albrecht

R. Aleksiejunas

F. Alessio

P. Alvarez Cartelle

R. Amalric

S. Amato

J.L. Amey

Y. Amhis

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

S. Arguedas Cuendis

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

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

S. Bashir

B. Batsukh

P.B. Battista

A. Bay

A. Beck

M. Becker

F. Bedeschi

Observation and investigation of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>T</mi><mrow><mi>c</mi><mover accent="true"><mi>c</mi><mo stretchy="false">¯</mo></mover><mn>1</mn></mrow></msub><mo stretchy="false">(</mo><mn>4430</mn><msup><mo stretchy="false">)</mo><mo>+</mo></msup></math> structure in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>B</mi><mo>+</mo></msup><mo stretchy="false">→</mo><mi>ψ</mi><mo stretchy="false">(</mo><mn>2</mn><mi>S</mi><mo stretchy="false">)</mo><msubsup><mi>K</mi><mi mathvariant="normal">S</mi><mn>0</mn></msubsup><msup><mi>π</mi><mo>+</mo></msup></math> decays