We use holography to study correlation functions of local operators in maximally supersymmetric Yang-Mills theories arising on the world-volume of D$\textit{p}$-branes in the large-$\textit{N}$ and strong-coupling limit. The relevant supergravity backgrounds obtained from the near-horizon limit of the D$\textit{p}$-branes enjoy a scaling similarity, which leads to an auxiliary AdS space of fractional dimension. This suggests that holographic correlation functions in this setup can be computed by integrating standard CFT correlators over the auxiliary extra dimensions. We apply this prescription to analytically compute two- and three-point correlators of scalar operators. The resulting two-point functions take a familiar CFT form but with shifted conformal dimensions, while the three-point correlators have a much more involved position dependence which we calculate explicitly in terms of a sum of Appell functions.

Belgium

Nikolay Bobev

Guillermo Mera Álvarez

Hynek Paul

Correlation functions for non-conformal D$\textit{p}$-brane holography

The observation of a resonance structure in the opening angle of the electron-positron pairs in the $$^{7}$$ Li(p,e $$^+$$ e $$^-$$ ) $$^{8}$$ Be reaction was claimed and interpreted as the production and subsequent decay of a hypothetical particle (X17). Similar excesses, consistent with this particle, were later observed in processes involving $$^{4}$$ He and $$^{12}$$ C nuclei with the same experimental technique. The MEG II apparatus at PSI, designed to search for the $$\mu ^+ \rightarrow \textrm{e}^+ \gamma $$ decay, can be exploited to investigate the existence of this particle and study its nature. Protons from a Cockroft–Walton accelerator, with an energy up to 1.1 MeV, were delivered on a dedicated Li-based target. The $$\gamma $$ and the e $$^{+}$$ e $$^{-}$$ pair emerging from the $$^8\textrm{Be}^*$$ transitions were studied with calorimeters and a spectrometer, featuring a broader angular acceptance than previous experiments. We present in this paper the analysis of a four-week data-taking in 2023 with a beam energy of 1080 keV, resulting in the excitation of two different resonances with Q-value 17.6 and 18.1 MeV. No significant signal was found, and limits at 90% C.L. on the branching ratios (relative to the $$\gamma $$ emission) of the two resonances to X17 were set, $$R_{17.6} <{1.8}\,\times \,10^{-6}$$ and $$R_{18.1} < {1.2}\,\times \,10^{-5}$$ in the mass range between $${16.5}\hbox { MeV}/\hbox {c}^{2}$$ and $${17.1}\hbox { MeV}/\hbox {c}^{2}$$ .

Russia

K. Afanaciev

Italy

A. Baldini

Japan

S. Ban

H. Benmansour

G. Boca

P. Cattaneo

G. Cavoto

F. Cei

M. Chiappini

A. Corvaglia

Switzerland

G. Maso

A. Bari

M. Gerone

L. Barusso

M. Francesconi

L. Galli

G. Gallucci

F. Gatti

L. Gerritzen

F. Grancagnolo

E. Grandoni

M. Grassi

D. Grigoriev

M. Hildebrandt

United Kingdom

F. Ignatov

F. Ikeda

T. Iwamoto

S. Karpov

P. Kettle

N. Khomutov

A. Kolesnikov

N. Kravchuk

V. Krylov

N. Kuchinskiy

F. Leonetti

W. Li

V. Malyshev

A. Matsushita

M. Meucci

S. Mihara

United States

W. Molzon

T. Mori

D. Nicolò

H. Nishiguchi

A. Ochi

W. Ootani

A. Oya

D. Palo

M. Panareo

A. Papa

V. Pettinacci

A. Popov

F. Renga

S. Ritt

M. Rossella

A. Rozhdestvensky

S. Scarpellini

P. Schwendimann

G. Signorelli

M. Takahashi

Y. Uchiyama

A. Venturini

B. Vitali

C. Voena

K. Yamamoto

R. Yokota

T. Yonemoto

Search for the X17 particle in $$^{7}\textrm{Li}(\textrm{p},\textrm{e}^+ \textrm{e}^{-}) ^{8}\textrm{Be}$$ processes with the MEG II detector

A study of the charmless baryonic decays $$ {B}_{(s)}^0\to {K}^0p\overline{p} $$ is presented, where $$ {B}_{(s)}^0 $$ denotes either a $\textit{B}$ or a $$ {B}_s^0 $$ meson. The analysis is based on proton-proton collision data collected by the LHCb experiment at centre-of-mass energies of 7, 8, and 13 TeV, corresponding to an integrated luminosity of 9 fb . The decay $$ {B}_s^0\to {K}^0p\overline{p} $$ is observed for the first time, with a measured branching fraction of (9$\textit{.}$14 $\textit{±}$ 1$\textit{.}$69 $\textit{±}$ 0$\textit{.}$90 $\textit{±}$ 0$\textit{.}$33 $\textit{±}$ 0$\textit{.}$20) $\textit{×}$ 10 and a significance of 5.6$\textit{σ}$. The uncertainties respectively account for statistical and systematic contributions, the precision of the branching fraction of the normalisation channel $\textit{B}$ $\textit{→ K}$ $\textit{π}$ $\textit{π}$ and the fragmentation fraction ratio $\textit{f}$ $\textit{/f}$ . The branching fraction determined for $$ {B}^0\to {K}^0p\overline{p} $$ is (2$\textit{.}$82 $\textit{±}$ 0$\textit{.}$08 $\textit{±}$ 0$\textit{.}$12 $\textit{±}$ 0$\textit{.}$10) $\textit{×}$ 10 , which is the most precise measurement to date.

Netherlands

R. Aaij

A. Abdelmotteleb

C. Abellan Beteta

F. Abudinén

T. Ackernley

A. Adefisoye

Spain

B. Adeva

M. Adinolfi

Sweden

P. Adlarson

France

C. Agapopoulou

C. Aidala

Z. Ajaltouni

S. Akar

K. Akiba

P. Albicocco

Germany

J. Albrecht

F. Alessio

Z. Aliouche

P. Alvarez Cartelle

R. Amalric

Brazil

S. Amato

J. Amey

Y. Amhis

China

L. An

L. Anderlini

M. Andersson

A. Andreianov

P. Andreola

M. Andreotti

D. Andreou

A. Anelli

D. Ao

F. Archilli

M. Argenton

Costa Rica

S. Arguedas Cuendis

A. Artamonov

M. Artuso

E. Aslanides

R. Ataíde Da Silva

M. Atzeni

B. Audurier

D. Bacher

I. Bachiller Perea

S. Bachmann

M. Bachmayer

J. Back

P. Baladron Rodriguez

V. Balagura

A. Balboni

W. Baldini

L. Balzani

H. Bao

J. Baptista de Souza Leite

C. Barbero Pretel

M. Barbetti

I. Barbosa

R. Barlow

M. Barnyakov

S. Barsuk

W. Barter

J. Bartz

Poland

S. Bashir

B. Batsukh

P. Battista

A. Bay

A. Beck

M. Becker

F. Bedeschi

I. Bediaga

N. Behling

S. Belin

K. Belous

I. Belov

I. Belyaev

G. Benane

G. Bencivenni

E. Ben-Haim

A. Berezhnoy

R. Bernet

S. Bernet Andres

A. Bertolin

C. Betancourt

F. Betti

J. Bex

Ia. Bezshyiko

Ukraine

O. Bezshyyko

J. Bhom

M. Bieker

N. Biesuz

P. Billoir

A. Biolchini

M. Birch

F. Bishop

A. Bitadze

A. Bizzeti

T. Blake

F. Blanc

J. Blank

S. Blusk

V. Bocharnikov

Observation of the decay $$ {B}_s^0\to {K}^0p\overline{p} $$ and measurement of the $$ {B}_{(s)}^0\to {K}^0p\overline{p} $$ branching fractions

<p>The first evidence for the decay <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>B</mi></mrow><mrow><mo>−</mo></mrow></msup><mo stretchy="false">→</mo><msup><mrow><mi>D</mi></mrow><mrow><mo>*</mo><mo>*</mo><mn>0</mn></mrow></msup><msup><mrow><mi>τ</mi></mrow><mrow><mo>−</mo></mrow></msup><msub><mrow><mover accent="true"><mrow><mi>ν</mi></mrow><mrow><mo stretchy="true">¯</mo></mrow></mover></mrow><mrow><mi>τ</mi></mrow></msub></mrow></math> is obtained using proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>9</mn><mtext> </mtext><mtext> </mtext><msup><mi>fb</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math>, at centre-of-mass energies of 7, 8, and 13 TeV. Here, the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>D</mi><mrow><mo>*</mo><mo>*</mo><mn>0</mn></mrow></msup></math> meson represents any of the three excited charm mesons <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>D</mi><mn>1</mn></msub><mo stretchy="false">(</mo><mn>2420</mn><msup><mo stretchy="false">)</mo><mn>0</mn></msup></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>D</mi><mn>2</mn><mo>*</mo></msubsup><mo stretchy="false">(</mo><mn>2460</mn><msup><mo stretchy="false">)</mo><mn>0</mn></msup></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>D</mi><mn>1</mn><mo>′</mo></msubsup><mo stretchy="false">(</mo><mn>2400</mn><msup><mo stretchy="false">)</mo><mn>0</mn></msup></math>. The <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>B</mi><mo>−</mo></msup><mo stretchy="false">→</mo><mrow><msup><mi>D</mi><mrow><mo>*</mo><mo>*</mo><mn>0</mn></mrow></msup><msup><mi>τ</mi><mo>−</mo></msup><msub><mover accent="true"><mi>ν</mi><mo stretchy="false">¯</mo></mover><mi>τ</mi></msub></mrow></math> signal is measured with a significance of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>3.5</mn><mi>σ</mi></math>, including systematic uncertainties. The combined branching fraction <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="script">B</mi><mo stretchy="false">(</mo><msup><mrow><mi>B</mi></mrow><mrow><mo>−</mo></mrow></msup><mo stretchy="false">→</mo><msubsup><mrow><mi>D</mi></mrow><mrow><mn>1</mn><mo>,</mo><mn>2</mn></mrow><mrow><mo>*</mo><mo>*</mo><mn>0</mn></mrow></msubsup><msup><mrow><mi>τ</mi></mrow><mrow><mo>−</mo></mrow></msup><msub><mrow><mover accent="true"><mrow><mi>ν</mi></mrow><mrow><mo stretchy="false">¯</mo></mrow></mover></mrow><mrow><mi>τ</mi></mrow></msub><mo stretchy="false">)</mo><mo>×</mo><mi mathvariant="script">B</mi><mo stretchy="false">(</mo><msubsup><mrow><mi>D</mi></mrow><mrow><mn>1</mn><mo>,</mo><mn>2</mn></mrow><mrow><mo>*</mo><mo>*</mo><mn>0</mn></mrow></msubsup><mo stretchy="false">→</mo><msup><mrow><mi>D</mi></mrow><mrow><mo>*</mo><mo>+</mo></mrow></msup><msup><mrow><mi>π</mi></mrow><mrow><mo>−</mo></mrow></msup><mo stretchy="false">)</mo></mrow></math>, where <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>D</mi><mrow><mn>1</mn><mo>,</mo><mn>2</mn></mrow><mrow><mo>*</mo><mo>*</mo><mn>0</mn></mrow></msubsup></math> denotes both <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>D</mi><mn>1</mn></msub><mo stretchy="false">(</mo><mn>2420</mn><msup><mo stretchy="false">)</mo><mn>0</mn></msup></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>D</mi><mn>2</mn><mo>*</mo></msubsup><mo stretchy="false">(</mo><mn>2460</mn><msup><mo stretchy="false">)</mo><mn>0</mn></msup></math> contributions, is measured to be <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mo stretchy="false">[</mo><mn>0.051</mn><mo>±</mo><mn>0.013</mn><mrow><mo stretchy="false">(</mo><mi>stat</mi><mo stretchy="false">)</mo></mrow><mo>±</mo><mn>0.006</mn><mrow><mo stretchy="false">(</mo><mi>syst</mi><mo stretchy="false">)</mo></mrow><mo>±</mo><mn>0.009</mn><mo stretchy="false">(</mo><mi>ext</mi><mo stretchy="false">)</mo><mo stretchy="false">]</mo><mo>%</mo></mrow></math>, where the last uncertainty reflects that of the branching fraction of the normalization channel <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>B</mi><mo>−</mo></msup><mo stretchy="false">→</mo><mrow><msubsup><mi>D</mi><mrow><mn>1</mn><mo>,</mo><mn>2</mn></mrow><mrow><mo>*</mo><mo>*</mo><mn>0</mn></mrow></msubsup><msup><msubsup><mi>D</mi><mi>s</mi><mo>−</mo></msubsup><mrow><mo stretchy="false">(</mo><mo>*</mo><mo stretchy="false">)</mo></mrow></msup></mrow></math>. The ratio between the tauonic and muonic semileptonic <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi></math> decays, with the latter taken from world average values, is also determined and found to be <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="script">R</mi><mo stretchy="false">(</mo><msubsup><mrow><mi>D</mi></mrow><mrow><mn>1</mn><mo>,</mo><mn>2</mn></mrow><mrow><mo>*</mo><mo>*</mo><mn>0</mn></mrow></msubsup><mo stretchy="false">)</mo><mo>=</mo><mn>0.13</mn><mo>±</mo><mn>0.03</mn><mrow><mo stretchy="false">(</mo><mi>stat</mi><mo stretchy="false">)</mo></mrow><mo>±</mo><mn>0.01</mn><mrow><mo stretchy="false">(</mo><mi>syst</mi><mo stretchy="false">)</mo></mrow><mo>±</mo><mn>0.02</mn><mo stretchy="false">(</mo><mi>ext</mi><mo stretchy="false">)</mo></mrow></math>.</p>

A.S.W. Abdelmotteleb

A.A. Adefisoye

C.A. Aidala

CERN

J.L. Amey

J.J. Back

I.R. Barbosa

Evidence for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>B</mi><mo>−</mo></msup><mo stretchy="false">→</mo><msup><mi>D</mi><mrow><mo>*</mo><mo>*</mo><mn>0</mn></mrow></msup><msup><mi>τ</mi><mo>−</mo></msup><mover accent="true"><msub><mi>ν</mi><mi>τ</mi></msub><mo stretchy="true">¯</mo></mover></math> Decays