Using a Drinfeld twist of Jordanian type, we construct a deformation of the non-compact and $$ \mathfrak{s}{\mathfrak{l}}_2 $$ -invariant $\textit{XXX}$ spin-chain. Before the deformation, the seed model can be understood as a sector of the $$ \mathfrak{psu} $$ (2, 2|4)-invariant spin-chain encoding the spectral problem of $$ \mathcal{N} $$ = 4 super Yang-Mills at one loop in the planar limit. The deformation gives rise to interesting features because, while being integrable, the Hamiltonian is non-hermitian and non-diagonalisable, so that it only admits a Jordan decomposition. Moreover, the eigenvalues of the deformed Hamiltonian coincide with those of the original undeformed spin-chain. We use explicit examples as well as the techniques of the coordinate and of the algebraic Bethe ansatz to discuss the construction of the (generalised) eigenvectors of the deformed model. We also show that the deformed spin-chain is equivalent to an undeformed one with twisted boundary conditions, and that it may be derived from a scaling limit of the non-compact $\textit{U}$ ( $$ \mathfrak{s}{\mathfrak{l}}_2 $$ )-invariant $\textit{XXZ}$ spin-chain.

Spain

Riccardo Borsato

Miguel Fernández

Jordanian deformation of the non-compact and $$ \mathfrak{s}{\mathfrak{l}}_2 $$ -invariant $\textit{XXX}$

Differential two-particle normalized cumulants ( $$R_2$$ ) and transverse momentum correlations ( $$P_2$$ ) are measured as a function of the relative pseudorapidity and azimuthal angle difference $$( \Delta \eta , \Delta \varphi )$$ of charged particle pairs in minimum bias pp collisions at $$\sqrt{\textit{s}}$$ = 13 TeV. The measurements use charged hadrons in the pseudorapidity region of $$|\eta | < 0.8$$ and the transverse momentum range 0.2 $$< \textit{p}_{\mathrm T} < $$ 2.0 $$\textrm{GeV}/\textit{c}$$ in order to focus on soft multiparticle interactions and to complement prior measurements of these correlation functions in p–Pb and Pb–Pb collisions. The correlation functions are reported for both unlike-sign and like-sign pairs and their charge-independent and charge-dependent combinations. Both the $$R_2$$ and $$P_2$$ measured in pp collisions exhibit features qualitatively similar to those observed in p–Pb and Pb–Pb collisions. The $$\Delta \eta $$ and $$\Delta \varphi $$ root mean square widths of the near-side peak of the correlation functions are evaluated and compared with those observed in p–Pb and Pb–Pb collisions and show smooth evolution with the multiplicity of charged particles produced in the collision. The comparison of the measured correlation functions with predictions from PYTHIA8 shows that this model qualitatively captures their basic structure and characteristics but feature important differences. In addition, the $$R_2^{\textrm{CD}}$$ is used to determine the charge balance function of hadrons produced within the detector acceptance of the measurements. The integral of the balance function is found to be compatible with those reported by a previous measurement in Pb–Pb collisions.

France

S. Acharya

India

A. Agarwal

Switzerland

G. Aglieri Rinella

Italy

L. Aglietta

M. Agnello

N. Agrawal

Z. Ahammed

S. Ahmad

South Korea

S. Ahn

Slovakia

I. Ahuja

A. Akindinov

Germany

V. Akishina

M. Al-Turany

D. Aleksandrov

B. Alessandro

China

H. Alfanda

Mexico

R. Alfaro Molina

B. Ali

A. Alici

United States

N. Alizadehvandchali

A. Alkin

Norway

J. Alme

G. Alocco

T. Alt

A. Altamura

I. Altsybeev

J. Alvarado

M. Anaam

Romania

C. Andrei

United Kingdom

N. Andreou

A. Andronic

E. Andronov

V. Anguelov

F. Antinori

P. Antonioli

N. Apadula

L. Aphecetche

H. Appelshäuser

C. Arata

S. Arcelli

R. Arnaldi

Brazil

J. Arneiro

I. Arsene

M. Arslandok

A. Augustinus

R. Averbeck

D. Averyanov

M. Azmi

Japan

H. Baba

A. Badalà

J. Bae

Y. Bae

Y. Baek

X. Bai

R. Bailhache

Y. Bailung

R. Bala

A. Balbino

A. Baldisseri

Poland

B. Balis

Z. Banoo

V. Barbasova

F. Barile

L. Barioglio

Greece

M. Barlou

B. Barman

Hungary

G. Barnaföldi

L. Barnby

E. Barreau

V. Barret

L. Barreto

C. Bartels

K. Barth

E. Bartsch

N. Bastid

Sweden

S. Basu

G. Batigne

D. Battistini

B. Batyunya

D. Bauri

Peru

J. Alba

Denmark

I. Bearden

C. Beattie

P. Becht

D. Behera

I. Belikov

A. Bell Hechavarria

F. Bellini

R. Bellwied

S. Belokurova

L. Beltran

Y. Beltran

G. Bencedi

A. Bensaoula

S. Beole

Y. Berdnikov

A. Berdnikova

L. Bergmann

M. Besoiu

L. Betev

Measurements of differential two-particle number and transverse momentum correlation functions in pp collisions at $$\sqrt{\textit{s}}$$ = 13 TeV

We derive two rigorous bounds on the spectrum of massive states that contributes to planar amplitudes in weakly coupled theories with massless scalars. First, we show that the presence of massive spinning states necessitates the existence of lighter states with lower spins. Explicitly, if there exists a massive state with spin $\textit{J}$ > 2, then there must be a state with spin $\textit{J}$ − 1 and a non-zero mass lower than that of the lightest spin-$\textit{J}$ state, a state with spin $\textit{J}$ − 2 and a mass lower than that of the lightest spin-($\textit{J}$ − 1) particle and so on until we reach a mass below which only states with spin less than 2 are exchanged. Second, we find that if there are spin-$\textit{J}$ states in the spectrum, the maximum mass of the lightest spin-($\textit{J}$ + 1) state is determined by the masses of the lightest spin-$\textit{J}$ and ($\textit{J}$ − 1) states. In the approximation that this bound applies to pion scattering in real world QCD, we find it gives a window of only ∼150 MeV for the expected mass of a yet unmeasured spin-7 meson.

Justin Berman

Analytic bounds on the spectrum of crossing symmetric S-matrices

<p>The first search for a heavy neutral spin-1 gauge boson (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>Z</mi></mrow><mrow><mo>′</mo></mrow></msup></mrow></math>) with nonuniversal fermion couplings produced via vector boson fusion processes and decaying to tau leptons or <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>W</mi></math> bosons is presented. The analysis is performed using LHC data 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>, collected from 2016 to 2018 with the CMS experiment and corresponding to an integrated luminosity of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>138</mn><mtext> </mtext><mtext> </mtext><msup><mrow><mi>fb</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></math>. The data are consistent with the standard model predictions. Upper limits are set on the product of the cross section for production of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>Z</mi></mrow><mrow><mo>′</mo></mrow></msup></mrow></math> boson and its branching fraction to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>τ</mi><mi>τ</mi></math> or <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>W</mi><mi>W</mi></math>. The presence of a <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>Z</mi></mrow><mrow><mo>′</mo></mrow></msup></mrow></math> boson decaying to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mrow><msup><mrow><mi>τ</mi></mrow><mrow><mo>+</mo></mrow></msup></mrow><mrow><msup><mrow><mi>τ</mi></mrow><mrow><mo>−</mo></mrow></msup></mrow></mrow></math> (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mrow><msup><mrow><mi>W</mi></mrow><mrow><mo>+</mo></mrow></msup></mrow><mrow><msup><mrow><mi>W</mi></mrow><mrow><mo>−</mo></mrow></msup></mrow></mrow></math>) is excluded for masses up to 2.45(1.60) TeV, depending on the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>Z</mi></mrow><mrow><mo>′</mo></mrow></msup></mrow></math> boson coupling to standard model weak bosons, and assuming a <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mrow><msup><mrow><mi>Z</mi></mrow><mrow><mo>′</mo></mrow></msup></mrow><mo stretchy="false">→</mo><mrow><msup><mrow><mi>τ</mi></mrow><mrow><mo>+</mo></mrow></msup></mrow><mrow><msup><mrow><mi>τ</mi></mrow><mrow><mo>−</mo></mrow></msup></mrow></mrow></math> (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mrow><msup><mrow><mi>W</mi></mrow><mrow><mo>+</mo></mrow></msup></mrow><mrow><msup><mrow><mi>W</mi></mrow><mrow><mo>−</mo></mrow></msup></mrow></mrow></math>) branching fraction of 50%.</p>

Armenia

A. Hayrapetyan

A. Tumasyan

Austria

W. Adam

J.W. Andrejkovic

L. Benato

T. Bergauer

S. Chatterjee

K. Damanakis

M. Dragicevic

P.S. Hussain

M. Jeitler

N. Krammer

A. Li

D. Liko

I. Mikulec

J. Schieck

R. Schöfbeck

D. Schwarz

M. Sonawane

W. Waltenberger

C.E. Wulz

Belgium

T. Janssen

T. Van Laer

P. Van Mechelen

N. Breugelmans

J. D’Hondt

S. Dansana

A. De Moor

M. Delcourt

F. Heyen

S. Lowette

I. Makarenko

D. Müller

S. Tavernier

M. Tytgat

G.P. Van Onsem

S. Van Putte

D. Vannerom

B. Bilin

B. Clerbaux

A.K. Das

I. De Bruyn

G. De Lentdecker

H. Evard

L. Favart

P. Gianneios

J. Jaramillo

A. Khalilzadeh

F.A. Khan

K. Lee

A. Malara

S. Paredes

M.A. Shahzad

L. Thomas

M. Vanden Bemden

C. Vander Velde

P. Vanlaer

M. De Coen

D. Dobur

G. Gokbulut

Y. Hong

J. Knolle

L. Lambrecht

D. Marckx

K. Mota Amarilo

K. Skovpen

Search for a Neutral Gauge Boson with Nonuniversal Fermion Couplings in Vector Boson Fusion Processes in Proton-Proton Collisions 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>