J. Giarra

activity

20162026

most citedFirst measurement of transverse-spin-dependent azimuthal asymmetries in the Drell-Yan process

122 citations · 740 across the 31 of their papers we have counts for

collaborators

31 papers

hep-ex2026

First Observation of an Exotic Reggeon

G. D. Alexeev, M. G. Alexeev, C. Alice +180

We present new \compass high-statistics measurements of the peripheral production of $η π^{-}$ and $η^{'} π^{-}$ pairs in the reactions $π^{-} p \to η^{(')} π^{-} p$ . For the first t…

hep-ex2025

Dihadron Transverse-Spin Asymmetries in Muon-Deuteron Deep-Inelastic Scattering

G. D. Alexeev, M. G. Alexeev, C. Alice +168

In 2022, the COMPASS collaboration performed semi-inclusive measurements of deep-inelastic muon-scattering on a transversely polarised deuteron (6LiD) target. From these data, tran…

hep-ex2025

Spectroscopy of Strange Mesons and First Observation of a Strange Crypto-Exotic State with $J^{P} = 0^{-}$

G. D. Alexeev, M. G. Alexeev, C. Alice +160

We measured the strange-meson spectrum in the scattering reaction $K^{-} + p \to K^{-} π^{-} π^{-} + p$ with the COMPASS spectrometer at CERN. Using the world's largest sample of…

hep-ex2024

Measurement of the hard exclusive $π^{0}$ muoproduction cross section at COMPASS

G. D. Alexeev, M. G. Alexeev, C. Alice +169

A new and detailed measurement of the cross section for hard exclusive neutral-pion muoproduction on the proton was performed in a wide kinematic region, with the photon virtuality…

hep-ex2023

High-statistics measurement of Collins and Sivers asymmetries for transversely polarised deuterons

G. D. Alexeev, M. G. Alexeev, C. Alice +183

New results are presented on a high-statistics measurement of Collins and Sivers asymmetries of charged hadrons produced in deep inelastic scattering of muons on a transversely pol…

hep-ex2023

Final COMPASS results on the transverse-spin-dependent azimuthal asymmetries in the pion-induced Drell-Yan process

G. D. Alexeev, M. G. Alexeev, C. Alice +180

The COMPASS Collaboration performed measurements of the Drell-Yan process in 2015 and 2018 using a 190 GeV/c $π^{-}$ beam impinging on a transversely polarised ammonia target. Comb…

hep-ex2023

Transverse-spin-dependent azimuthal asymmetries of pion and kaon pairs produced in muon-proton and muon-deuteron semi-inclusive deep inelastic scattering

The COMPASS Collaboration

A set of measurements of azimuthal asymmetries in the production of pairs of identified hadrons in deep-inelastic scattering of muons on transversely polarised $^{6}$ LiD (deuteron) a…

hep-ex2022★ 9 cited

Collins and Sivers transverse-spin asymmetries in inclusive muoproduction of $ρ^{0}$ mesons

G. D. Alexeev, M. G. Alexeev, C. Alice +188

The production of vector mesons in deep inelastic scattering is an interesting yet scarsely explored channel to study the transverse spin structure of the nucleon and the related p…

hep-ex2022★ 1 cited

Spin Density Matrix Elements in Exclusive $ρ^{0}$ Meson Muoproduction

G. D. Alexeev, M. G. Alexeev, C. Alice +186

We report on a measurement of Spin Density Matrix Elements (SDMEs) in hard exclusive $ρ^{0}$ meson muoproduction at COMPASS using 160~GeV/ $c$ polarised $μ^{+}$ and $μ^{-}$ beams im…

hep-ex2022★ 2 cited

Double $J / ψ$ production in pion-nucleon scattering at COMPASS

G. D. Alexeev, M. G. Alexeev, A. Amoroso +191

We present the study of the production of double $J / ψ$ mesons using COMPASS data collected with a 190 GeV/ $c$ $π^{-}$ beam scattering off NH $_{3}$ , Al and W targets. Kinematic distri…

hep-ex2021★ 23 cited

The exotic meson $π_{1} (1600)$ with $J^{P C} = 1^{-+}$ and its decay into $ρ (770) π$

M. G. Alexeev, G. D. Alexeev, A. Amoroso +192

We study the spin-exotic $J^{P C} = 1^{-+}$ amplitude in single-diffractive dissociation of 190 GeV $/ c$ pions into $π^{-} π^{-} π^{+}$ using a hydrogen target and confirm the $π_1(1600) \to…

hep-ex2021

Probing transversity by measuring $Λ$ polarisation in SIDIS

M. G. Alexeev, G. D. Alexeev, A. Amoroso +196

Based on the observation of sizeable target-transverse-spin asymmetries in single-hadron and hadron-pair production in Semi-Inclusive measurements of Deep Inelastic Scattering (SID…

hep-ex2020★ 12 cited

Spin Density Matrix Elements in Exclusive $ω$ Meson Muoproduction $^{*}$

M. G. Alexeev, G. D. Alexeev, A. Amoroso +197

We report on a measurement of Spin Density Matrix Elements (SDMEs) in hard exclusive $ω$ meson muoproduction on the proton at COMPASS using 160 GeV/ $c$ polarised $μ^{+}$ and $ μ^{…

hep-ph2020★ 36 cited

Triangle Singularity as the Origin of the $a_{1} (1420)$

G. D. Alexeev, M. G. Alexeev, A. Amoroso +194

The COMPASS experiment recently discovered a new isovector resonance-like signal with axial-vector quantum numbers, the $a_{1} (1420)$ , decaying to $f_{0} (980) π$ . With a mass too close…

hep-ex2019★ 9 cited

Contribution of exclusive diffractive processes to the measured azimuthal asymmetries in SIDIS

J. Agarwala, M. G. Alexeev, G. D. Alexeev +203

Hadron leptoproduction in Semi-Inclusive measurements of Deep-Inelastic Scattering (SIDIS) on unpolarised nucleons allows one to get information on the intrinsic transverse momentu…

hep-ex2019★ 24 cited

Measurement of the cross section for hard exclusive $π^{0}$ leptoproduction

M. G. Alexeev, G. D. Alexeev, A. Amoroso +199

We report on a measurement of hard exclusive $π^{0}$ muoproduction on the proton by COMPASS using 160 GeV/ $c$ polarised $μ^{+}$ and $μ^{-}$ beams of the CERN SPS impinging on a liquid hy…

hep-ex2018★ 22 cited

Measurement of $P_{T}$ -weighted Sivers asymmetries in leptoproduction of hadrons

M. G. Alexeev, G. D. Alexeev, A. Amoroso +209

The transverse spin asymmetries measured in semi-inclusive leptoproduction of hadrons, when weighted with the hadron transverse momentum $P_{T}$ , allow for the extraction of importan…

hep-ex2018★ 42 cited

Letter of Intent: A New QCD facility at the M2 beam line of the CERN SPS (COMPASS++/AMBER)

B. Adams, C. A. Aidala, R. Akhunzyanov +263

A New QCD facility at the M2 beam line of the CERN SPS COMPASS++/AMBER

hep-ex2018★ 76 cited

Light isovector resonances in $π^{-} p \to π^{-} π^{-} π^{+} p$ at 190 GeV/ $c$

M. Aghasyan, M. G. Alexeev, G. D. Alexeev +221

We have performed the most comprehensive resonance-model fit of $π^{-} π^{-} π^{+}$ states using the results of our previously published partial-wave analysis (PWA) of a large data set of…

hep-ex2018★ 47 cited

Transverse Extension of Partons in the Proton probed by Deeply Virtual Compton Scattering

R. Akhunzyanov, M. G. Alexeev, G. D. Alexeev +223

We report on the first measurement of exclusive single-photon muoproduction on the proton by COMPASS using 160 GeV/ $c$ polarized $μ^{+}$ and $μ^{-}$ beams of the CERN SPS impinging on…

hep-ex2018★ 15 cited

K $^{-}$ over K $^{+}$ multiplicity ratio for kaons produced in DIS with a large fraction of the virtual-photon energy

R. Akhunzyanov, M. G. Alexeev, G. D. Alexeev +207

The K $^{-}$ over K $^{+}$ multiplicity ratio is measured in deep-inelastic scattering, for the first time for kaons carrying a large fraction $z$ of the virtual-photon energy. The d…

hep-ex2018

First measurement of transverse-spin-dependent azimuthal asymmetries in the Drell-Yan process

Bakur Parsamyan

The COMPASS experiment at CERN, as part of its programme addresses the exploration of the transverse spin structure of the nucleon by measuring spin (in)dependent azimuthal asymmet…

hep-ex2017★ 28 cited

Longitudinal double-spin asymmetry $A_{1}^{p}$ and spin-dependent structure function $g_{1}^{p}$ of the proton at small values of $x$ and $Q^{2}$

M. Aghasyan, R. Akhunzyanov, M. G. Alexeev +225

We present a precise measurement of the proton longitudinal double-spin asymmetry $A_{1}^{p}$ and the proton spin-dependent structure function $g_{1}^{p}$ at photon virtualitie…

hep-ex2017★ 60 cited

Transverse-momentum-dependent Multiplicities of Charged Hadrons in Muon-Deuteron Deep Inelastic Scattering

M. Aghasyan, R. Akhunzyanov, M. G. Alexeev +227

A semi-inclusive measurement of charged hadron multiplicities in deep inelastic muon scattering off an isoscalar target was performed using data collected by the COMPASS Collaborat…

First Observation of an Exotic Reggeon

Dihadron Transverse-Spin Asymmetries in Muon-Deuteron Deep-Inelastic Scattering

Spectroscopy of Strange Mesons and First Observation of a Strange Crypto-Exotic State with JP=0−

Measurement of the hard exclusive π0 muoproduction cross section at COMPASS

High-statistics measurement of Collins and Sivers asymmetries for transversely polarised deuterons

Final COMPASS results on the transverse-spin-dependent azimuthal asymmetries in the pion-induced Drell-Yan process

Transverse-spin-dependent azimuthal asymmetries of pion and kaon pairs produced in muon-proton and muon-deuteron semi-inclusive deep inelastic scattering

Collins and Sivers transverse-spin asymmetries in inclusive muoproduction of ρ0 mesons

Spin Density Matrix Elements in Exclusive ρ0 Meson Muoproduction

Double J/ψ production in pion-nucleon scattering at COMPASS

The exotic meson π1​(1600) with JPC=1−+ and its decay into ρ(770)π

Probing transversity by measuring Λ polarisation in SIDIS

Spin Density Matrix Elements in Exclusive ω Meson Muoproduction ∗

Triangle Singularity as the Origin of the a1​(1420)

Contribution of exclusive diffractive processes to the measured azimuthal asymmetries in SIDIS

Measurement of the cross section for hard exclusive π0 leptoproduction

Measurement of PT​-weighted Sivers asymmetries in leptoproduction of hadrons

Letter of Intent: A New QCD facility at the M2 beam line of the CERN SPS (COMPASS++/AMBER)

Light isovector resonances in π−p→π−π−π+p at 190 GeV/c

Transverse Extension of Partons in the Proton probed by Deeply Virtual Compton Scattering

K− over K+ multiplicity ratio for kaons produced in DIS with a large fraction of the virtual-photon energy

First measurement of transverse-spin-dependent azimuthal asymmetries in the Drell-Yan process

Longitudinal double-spin asymmetry A1p​ and spin-dependent structure function g1p​ of the proton at small values of x and Q2

Transverse-momentum-dependent Multiplicities of Charged Hadrons in Muon-Deuteron Deep Inelastic Scattering

Spectroscopy of Strange Mesons and First Observation of a Strange Crypto-Exotic State with $J^{P} = 0^{-}$

Measurement of the hard exclusive $π^{0}$ muoproduction cross section at COMPASS

Collins and Sivers transverse-spin asymmetries in inclusive muoproduction of $ρ^{0}$ mesons

Spin Density Matrix Elements in Exclusive $ρ^{0}$ Meson Muoproduction

Double $J / ψ$ production in pion-nucleon scattering at COMPASS

The exotic meson $π_{1} (1600)$ with $J^{P C} = 1^{-+}$ and its decay into $ρ (770) π$

Probing transversity by measuring $Λ$ polarisation in SIDIS

Spin Density Matrix Elements in Exclusive $ω$ Meson Muoproduction $^{*}$

Triangle Singularity as the Origin of the $a_{1} (1420)$

Measurement of the cross section for hard exclusive $π^{0}$ leptoproduction

Measurement of $P_{T}$ -weighted Sivers asymmetries in leptoproduction of hadrons

Light isovector resonances in $π^{-} p \to π^{-} π^{-} π^{+} p$ at 190 GeV/ $c$

K $^{-}$ over K $^{+}$ multiplicity ratio for kaons produced in DIS with a large fraction of the virtual-photon energy

Longitudinal double-spin asymmetry $A_{1}^{p}$ and spin-dependent structure function $g_{1}^{p}$ of the proton at small values of $x$ and $Q^{2}$