We propose a novel mechanism for the production of gravitational waves in the early Universe that originates from the relaxation processes induced by the QCD phase transition. While the energy density of the quark-gluon mean-field is monotonously decaying in real time, its pressure undergoes a series of violent oscillations at the characteristic QCD time scales that generate a primordial multi-peaked gravitational waves signal in the radio frequencies’ domain. The signal is an echo of the QCD phase transition that is accessible by planned measurements at the FAST and SKA telescopes.

China

Andrea Addazi

Antonino Marcianò

Sweden

Roman Pasechnik

Time-crystal ground state and production of gravitational waves from QCD phase transition A.A and A.M. acknowledge support by the NSFC(11875113), the Shanghai Municipality(KBH1512299), and by Fudan University(JJH1512105). R.P. was partially supported by the Swedish Research Council, contract numbers 621-2013-428 and 2016-05996, by CONICYT grant MEC80170112 (Chile), as well as by the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme(668679). This work was supported in part by the Ministry of Education, Youth and Sports of the Czech Republic, project LT17018. The work has been performed in the framework of COST Action CA15213 “Theory of hot matter and relativistic heavy-ion collisions” (THOR)

Inclusive J/ Ï production has been studied with the ALICE detector in p-Pb collisions at the nucleon-nucleon center of mass energy $ \sqrt{{{s_{\mathrm{NN}}}}} $ = 5.02 TeV at the CERN LHC. The measurement is performed in the center of mass rapidity domains 2.03 &lt; y cms &lt; 3 . 53 and â4 . 46 &lt; y cms &lt; â2 . 96, down to zero transverse momentum, studying the Î¼ + Î¼ â decay mode. In this paper, the J/ Ï production cross section and the nuclear modification factor R pPb for the rapidities under study are presented. While at forward rapidity, corresponding to the proton direction, a suppression of the J/ Ï yield with respect to binary-scaled pp collisions is observed, in the backward region no suppression is present. The ratio of the forward and backward yields is also measured differentially in rapidity and transverse momentum. Theoretical predictions based on nuclear shadowing, as well as on models including, in addition, a contribution from partonic energy loss, are in fair agreement with the experimental results.

United States

B. Abelev

Czechia

J. Adam

D. AdamovÃ¡

A.M. Adare

India

M.M. Aggarwal

CERN

G. Aglieri Rinella

Italy

M. Agnello

Hungary

A.G. Agocs

A. Agostinelli

Z. Ahammed

N. Ahmad

A. Ahmad Masoodi

Pakistan

I. Ahmed

South Korea

S.U. Ahn

S.A. Ahn

I. Aimo

S. Aiola

M. Ajaz

Russia

A. Akindinov

D. Aleksandrov

B. Alessandro

United Kingdom

D. Alexandre

A. Alici

Ukraine

A. Alkin

Norway

J. Alme

Germany

T. Alt

V. Altini

S. Altinpinar

I. Altsybeev

Brazil

C. Alves Garcia Prado

Romania

C. Andrei

A. Andronic

V. Anguelov

J. Anielski

Croatia

T. AntiÄiÄ

F. Antinori

P. Antonioli

France

L. Aphecetche

H. AppelshÃ¤user

N. Arbor

S. Arcelli

Spain

N. Armesto

R. Arnaldi

T. Aronsson

I.C. Arsene

M. Arslandok

A. Augustinus

R. Averbeck

T.C. Awes

South Africa

M.D. Azmi

M. Bach

A. BadalÃ

Y.W. Baek

R. Bailhache

V. Bairathi

R. Bala

A. Baldisseri

F. Baltasar Dos Santos Pedrosa

Slovakia

J. BÃ¡n

R.C. Baral

R. Barbera

F. Barile

G.G. BarnafÃ¶ldi

L.S. Barnby

V. Barret

Poland

J. Bartke

M. Basile

N. Bastid

S. Basu

B. Bathen

G. Batigne

JINR

B. Batyunya

P.C. Batzing

C. Baumann

Denmark

I.G. Bearden

H. Beck

N.K. Behera

I. Belikov

F. Bellini

R. Bellwied

Mexico

E. Belmont-Moreno

G. Bencedi

S. Beole

I. Berceanu

A. Bercuci

Y. Berdnikov

D. Berenyi

A.A.E. Bergognon

Netherlands

R.A. Bertens

D. Berzano

L. Betev

A. Bhasin

A.K. Bhati

Japan

J. Bhom

N. Bianchi

L. Bianchi

J. BielÄÃ­k

J. BielÄÃ­kovÃ¡

A. Bilandzic

S. Bjelogrlic

J/ Ï production and nuclear effects in p-Pb collisions at $ \sqrt{{{{\mathrm{s}}_{\mathrm{NN}}}}} $ = 5.02 TeV

In this Letter, comprehensive results on π± , K± , KS0 , p( p¯ ) and Λ(Λ¯) production at mid-rapidity ( 0&lt;yCMS&lt;0.5 ) in p–Pb collisions at sNN=5.02 TeV , measured by the ALICE detector at the LHC, are reported. The transverse momentum distributions exhibit a hardening as a function of event multiplicity, which is stronger for heavier particles. This behavior is similar to what has been observed in pp and Pb–Pb collisions at the LHC. The measured pT distributions are compared to d–Au, Au–Au and Pb–Pb results at lower energy and with predictions based on QCD-inspired and hydrodynamic models.

D. Adamová

T. Antičić

H. Appelshäuser

J. Bán

G.G. Barnaföldi

J. Bielčík

J. Bielčíková

Multiplicity dependence of pion, kaon, proton and lambda production in p–Pb collisions at sNN=5.02 TeV

The production of Ξ− and Ω− baryons and their anti-particles in Pb–Pb collisions at sNN=2.76 TeV has been measured using the ALICE detector. The transverse momentum spectra at mid-rapidity ( |y|&lt;0.5 ) for charged Ξ and Ω hyperons have been studied in the range 0.6&lt;pT&lt;8.0 GeV/c and 1.2&lt;pT&lt;7.0 GeV/c , respectively, and in several centrality intervals (from the most central 0–10% to the most peripheral 60–80% collisions). These spectra have been compared with the predictions of recent hydrodynamic models. In particular, the Kraków and EPOS models give a satisfactory description of the data, with the latter covering a wider pT range. Mid-rapidity yields, integrated over pT , have been determined. The hyperon-to-pion ratios are similar to those at RHIC: they rise smoothly with centrality up to 〈Npart〉∼150 and saturate thereafter. The enhancements (yields per participant nucleon relative to those in pp collisions) increase both with the strangeness content of the baryon and with centrality, but are less pronounced than at lower energies.

C. Bianchin

Multi-strange baryon production at mid-rapidity in Pb–Pb collisions at sNN=2.76 TeV