Pub Date : 2019-12-20DOI: 10.1142/9789811219313_0005
Beijiang Liu
The study of light hadrons is central to the understanding of confinement--a unique property of QCD. The quark model describs mesons as bound states of quarks and antiquarks. LQCD and QCD-motivated models for hadrons, however, predict a richer spectrum of mesons that takes into account not only the quark degrees of freedom but also the gluonic degrees of freedom. A selection of recent progress in the light-quark sector with unprecedented high-statistics data sets from $e^+e^-$ experiments are reviewed.
{"title":"Light meson spectroscopy at e+e− machines","authors":"Beijiang Liu","doi":"10.1142/9789811219313_0005","DOIUrl":"https://doi.org/10.1142/9789811219313_0005","url":null,"abstract":"The study of light hadrons is central to the understanding of confinement--a unique property of QCD. The quark model describs mesons as bound states of quarks and antiquarks. LQCD and QCD-motivated models for hadrons, however, predict a richer spectrum of mesons that takes into account not only the quark degrees of freedom but also the gluonic degrees of freedom. A selection of recent progress in the light-quark sector with unprecedented high-statistics data sets from $e^+e^-$ experiments are reviewed.","PeriodicalId":8429,"journal":{"name":"arXiv: High Energy Physics - Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90381394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
F. Abusaif, A. Aggarwal, A. Aksentev, B. Alberdi-Esuain, A. Andres, A. Atanasov, L. Barion, S. Basile, M. Berz, C. Bohme, J. Boker, J. Borburgh, N. Canale, C. Carli, I. Ciepał, G. Ciullo, M. Contalbrigo, J. D. Conto, S. Dymov, O. Felden, M. Gaisser, R. Gebel, N. Giese, J. Gooding, K. Grigoryev, D. Grzonka, M. Tahar, T. Hahnraths, D. Heberling, V. Hejny, J. Hetzel, D. Holscher, O. Javakhishvili, L. Jorat, A. Kacharava, V. Kamerdzhiev, S. Karanth, I. Keshelashvili, I. Koop, A. Kulikov, K. Laihem, M. Lamont, A. Lehrach, P. Lenisa, I. Lomidze, N. Lomidze, B. Lorentz, G. Macharashvili, A. Magiera, K. Makino, S. Martin, D. Mchedlishvili, U. Meissner, Z. Metreveli, J. Michaud, F. Muller, A. Nass, G. Natour, N. Nikolaev, A. Nogga, D. Okropiridze, A. Pesce, V. Poncza, D. Prasuhn, J. Pretz, F. Rathmann, J. Ritman, M. Rosenthal, A. Saleev, M. Schott, T. Sefzick, Y. Senichev, R. Shankar, D. Shergelashvili, V. Shmakova, S. Siddique, A. Silenko, M. Simon, J. Slim, H. Soltner, A. Stahl, R. Stassen, E. Stephenson, H. Str
The proposed method exploits charged particles confined as a storage ring beam (proton, deuteron, possibly helium-3) to search for an intrinsic electric dipole moment (EDM) aligned along the particle spin axis. Statistical sensitivities could approach 10$^{-29}$ e$cdot$cm. The challenge will be to reduce systematic errors to similar levels. The ring will be adjusted to preserve the spin polarisation, initially parallel to the particle velocity, for times in excess of 15 minutes. Large radial electric fields, acting through the EDM, will rotate the polarisation. The slow rise in the vertical polarisation component, detected through scattering from a target, signals the EDM. The project strategy is outlined. It foresees a step-wise plan, starting with ongoing COSY (Cooler Synchrotron, Forschungszentrum J"ulich) activities that demonstrate technical feasibility. Achievements to date include reduced polarisation measurement errors, long horizontal-plane polarisation lifetimes, and control of the polarisation direction through feedback from the scattering measurements. The project continues with a proof-of-capability measurement (precursor experiment; first direct deuteron EDM measurement), an intermediate prototype ring (proof-of-principle; demonstrator for key technologies), and finally the high precision electric-field storage ring.
{"title":"Storage Ring to Search for Electric Dipole Moments of Charged Particles -- Feasibility Study","authors":"F. Abusaif, A. Aggarwal, A. Aksentev, B. Alberdi-Esuain, A. Andres, A. Atanasov, L. Barion, S. Basile, M. Berz, C. Bohme, J. Boker, J. Borburgh, N. Canale, C. Carli, I. Ciepał, G. Ciullo, M. Contalbrigo, J. D. Conto, S. Dymov, O. Felden, M. Gaisser, R. Gebel, N. Giese, J. Gooding, K. Grigoryev, D. Grzonka, M. Tahar, T. Hahnraths, D. Heberling, V. Hejny, J. Hetzel, D. Holscher, O. Javakhishvili, L. Jorat, A. Kacharava, V. Kamerdzhiev, S. Karanth, I. Keshelashvili, I. Koop, A. Kulikov, K. Laihem, M. Lamont, A. Lehrach, P. Lenisa, I. Lomidze, N. Lomidze, B. Lorentz, G. Macharashvili, A. Magiera, K. Makino, S. Martin, D. Mchedlishvili, U. Meissner, Z. Metreveli, J. Michaud, F. Muller, A. Nass, G. Natour, N. Nikolaev, A. Nogga, D. Okropiridze, A. Pesce, V. Poncza, D. Prasuhn, J. Pretz, F. Rathmann, J. Ritman, M. Rosenthal, A. Saleev, M. Schott, T. Sefzick, Y. Senichev, R. Shankar, D. Shergelashvili, V. Shmakova, S. Siddique, A. Silenko, M. Simon, J. Slim, H. Soltner, A. Stahl, R. Stassen, E. Stephenson, H. Str","doi":"10.23731/CYRM-2021-003","DOIUrl":"https://doi.org/10.23731/CYRM-2021-003","url":null,"abstract":"The proposed method exploits charged particles confined as a storage ring beam (proton, deuteron, possibly helium-3) to search for an intrinsic electric dipole moment (EDM) aligned along the particle spin axis. Statistical sensitivities could approach 10$^{-29}$ e$cdot$cm. The challenge will be to reduce systematic errors to similar levels. The ring will be adjusted to preserve the spin polarisation, initially parallel to the particle velocity, for times in excess of 15 minutes. Large radial electric fields, acting through the EDM, will rotate the polarisation. The slow rise in the vertical polarisation component, detected through scattering from a target, signals the EDM. The project strategy is outlined. It foresees a step-wise plan, starting with ongoing COSY (Cooler Synchrotron, Forschungszentrum J\"ulich) activities that demonstrate technical feasibility. Achievements to date include reduced polarisation measurement errors, long horizontal-plane polarisation lifetimes, and control of the polarisation direction through feedback from the scattering measurements. The project continues with a proof-of-capability measurement (precursor experiment; first direct deuteron EDM measurement), an intermediate prototype ring (proof-of-principle; demonstrator for key technologies), and finally the high precision electric-field storage ring.","PeriodicalId":8429,"journal":{"name":"arXiv: High Energy Physics - Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76184752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-11-29DOI: 10.1142/9789811219313_0078
F. Krinner
Modern hadron-spectroscopy experiments such as COMPASS collect data samples of unprecedented size, so that novel analysis techniques become possible and necessary. One such technique is the freed-isobar partial-wave analysis (PWA). In this approach, fixed parametrizations for the amplitudes of intermediate states commonly modeled using Breit-Wigner shapes are replaced by sets of step-like functions that are determined from the data. This approach not only reduces the model dependence of partial-wave analyses, but also allows us to study the amplitudes of the intermediate states and their dependence on the parent system. We will also present results of a freed-isobar PWA performed on the large data set on diffractive production of three charged pions collected by the COMPASS experiment, which consists of $46times10^6$ exclusive events. We will focus on results for the wave with spin-exotic quantum numbers $J^{PC}=1^{-+}$, in particular on its decay into $rho(770)pi$. Here, the freed-isobar PWA method provides insight into the interplay of three- and two-particle dynamics and confirms the decay of the spin-exotic $pi_1(1600)$ resonance to $rho(770)pi$ in a model-independent way.
{"title":"Freed-isobar analysis of light mesons at COMPASS","authors":"F. Krinner","doi":"10.1142/9789811219313_0078","DOIUrl":"https://doi.org/10.1142/9789811219313_0078","url":null,"abstract":"Modern hadron-spectroscopy experiments such as COMPASS collect data samples of unprecedented size, so that novel analysis techniques become possible and necessary. One such technique is the freed-isobar partial-wave analysis (PWA). In this approach, fixed parametrizations for the amplitudes of intermediate states commonly modeled using Breit-Wigner shapes are replaced by sets of step-like functions that are determined from the data. This approach not only reduces the model dependence of partial-wave analyses, but also allows us to study the amplitudes of the intermediate states and their dependence on the parent system. \u0000We will also present results of a freed-isobar PWA performed on the large data set on diffractive production of three charged pions collected by the COMPASS experiment, which consists of $46times10^6$ exclusive events. We will focus on results for the wave with spin-exotic quantum numbers $J^{PC}=1^{-+}$, in particular on its decay into $rho(770)pi$. Here, the freed-isobar PWA method provides insight into the interplay of three- and two-particle dynamics and confirms the decay of the spin-exotic $pi_1(1600)$ resonance to $rho(770)pi$ in a model-independent way.","PeriodicalId":8429,"journal":{"name":"arXiv: High Energy Physics - Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82977701","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Y. Kamiya, R. Cubitt, L. Porcar, O. Zimmer, G. Kim, S. Komamiya
Improved limits for new gravity-like short-range interactions, in which a scattering potential is modeled by the Yukawa-type parametrization, have been obtained by measuring the angular distribution of 6 A neutrons scattering from atomic xenon gas. We have collected approximately $1.4 times 10^8$ small-angle neutron scattering events. The data are interpreted as no evidence of new forces and show improved upper limits on the coupling strength in the interaction range of $0.3$ nm to $9$ nm. These improved constraints are also interpreted as new limits for a model, in which a charge of the new forces is expressed as a linear combination of the baryon number and the lepton number.
{"title":"Experimental search for Non-Newtonian forces in the nanometer scale with slow neutrons","authors":"Y. Kamiya, R. Cubitt, L. Porcar, O. Zimmer, G. Kim, S. Komamiya","doi":"10.1063/5.0036985","DOIUrl":"https://doi.org/10.1063/5.0036985","url":null,"abstract":"Improved limits for new gravity-like short-range interactions, in which a scattering potential is modeled by the Yukawa-type parametrization, have been obtained by measuring the angular distribution of 6 A neutrons scattering from atomic xenon gas. We have collected approximately $1.4 times 10^8$ small-angle neutron scattering events. The data are interpreted as no evidence of new forces and show improved upper limits on the coupling strength in the interaction range of $0.3$ nm to $9$ nm. These improved constraints are also interpreted as new limits for a model, in which a charge of the new forces is expressed as a linear combination of the baryon number and the lepton number.","PeriodicalId":8429,"journal":{"name":"arXiv: High Energy Physics - Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77509638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-11-15DOI: 10.1103/PHYSREVD.102.052007
C. C. D. Akimov, Peibo An, C. Awe, P. Barbeau, B. Becker, V. Belov, M. Blackston, A. Bolozdynya, B. Cabrera-Palmer, N. Chen, E. Conley, R. Cooper, J. Daughhetee, M. D. V. Coello, J. Detwiler, M. Durand, Y. Efremenko, S. Elliott, L. Fabris, M. Febbraro, W. Fox, A. Galindo-Uribarri, M. Green, K. S. Hansen, M. Heath, S. Hedges, T. Johnson, M. Kaemingk, L. Kaufman, A. Khromov, A. Konovalov, E. Kozlova, A. Kumpan, L. Li, J. Librande, J. Link, J. Liu, K. Mann, D. Markoff, H. Moreno, P. Mueller, J. Newby, D. Parno, S. Penttila, D. Pershey, D. Radford, R. Rapp, H. Ray, J. Raybern, O. Razuvaeva, D. Reyna, G. Rich, D. Rudik, J. Runge, D. Salvat, K. Scholberg, A. Shakirov, G. Simakov, G. Sinev, W. Snow, V. Sosnovtsev, B. Suh, R. Tayloe, K. Tellez-Giron-Flores, R. Thornton, I. Tolstukhin, J. Vanderwerp, R. Varner, C. Virtue, G. Visser, C. Wiseman, T. Wongjirad, J. Yang, Y. Yen, J. Yoo, C.-H. Yu, J. Zettlemoyer
The COHERENT experiment is well poised to test sub-GeV dark matter models using low-energy recoil detectors sensitive to coherent elastic neutrino-nucleus scattering (CEvNS) in the $pi$-DAR neutrino beam produced by the Spallation Neutron Source. We show how a planned 750-kg liquid argon scintillation detector would place leading limits on scalar light dark matter models, over two orders of magnitude of dark matter mass, for dark matter particles produced through vector and leptophobic portals in the absence of other effects beyond the standard model. The characteristic timing structure of a $pi$-DAR beam allows a unique opportunity for constraining systematic uncertainties on the standard model background in a time window where signal is not expected, enhancing expected sensitivity. Additionally, we discuss future prospects, further increasing the discovery potential of CEvNS detectors. Such methods would test the calculated thermal dark matter abundance for all couplings $alpha'leq1$ within the vector portal model over an order of magnitude of dark matter masses.
{"title":"Sensitivity of the COHERENT experiment to accelerator-produced dark matter","authors":"C. C. D. Akimov, Peibo An, C. Awe, P. Barbeau, B. Becker, V. Belov, M. Blackston, A. Bolozdynya, B. Cabrera-Palmer, N. Chen, E. Conley, R. Cooper, J. Daughhetee, M. D. V. Coello, J. Detwiler, M. Durand, Y. Efremenko, S. Elliott, L. Fabris, M. Febbraro, W. Fox, A. Galindo-Uribarri, M. Green, K. S. Hansen, M. Heath, S. Hedges, T. Johnson, M. Kaemingk, L. Kaufman, A. Khromov, A. Konovalov, E. Kozlova, A. Kumpan, L. Li, J. Librande, J. Link, J. Liu, K. Mann, D. Markoff, H. Moreno, P. Mueller, J. Newby, D. Parno, S. Penttila, D. Pershey, D. Radford, R. Rapp, H. Ray, J. Raybern, O. Razuvaeva, D. Reyna, G. Rich, D. Rudik, J. Runge, D. Salvat, K. Scholberg, A. Shakirov, G. Simakov, G. Sinev, W. Snow, V. Sosnovtsev, B. Suh, R. Tayloe, K. Tellez-Giron-Flores, R. Thornton, I. Tolstukhin, J. Vanderwerp, R. Varner, C. Virtue, G. Visser, C. Wiseman, T. Wongjirad, J. Yang, Y. Yen, J. Yoo, C.-H. Yu, J. Zettlemoyer","doi":"10.1103/PHYSREVD.102.052007","DOIUrl":"https://doi.org/10.1103/PHYSREVD.102.052007","url":null,"abstract":"The COHERENT experiment is well poised to test sub-GeV dark matter models using low-energy recoil detectors sensitive to coherent elastic neutrino-nucleus scattering (CEvNS) in the $pi$-DAR neutrino beam produced by the Spallation Neutron Source. We show how a planned 750-kg liquid argon scintillation detector would place leading limits on scalar light dark matter models, over two orders of magnitude of dark matter mass, for dark matter particles produced through vector and leptophobic portals in the absence of other effects beyond the standard model. The characteristic timing structure of a $pi$-DAR beam allows a unique opportunity for constraining systematic uncertainties on the standard model background in a time window where signal is not expected, enhancing expected sensitivity. Additionally, we discuss future prospects, further increasing the discovery potential of CEvNS detectors. Such methods would test the calculated thermal dark matter abundance for all couplings $alpha'leq1$ within the vector portal model over an order of magnitude of dark matter masses.","PeriodicalId":8429,"journal":{"name":"arXiv: High Energy Physics - Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73370594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-11-07DOI: 10.1007/978-3-030-53448-6_39
P. Dhankher
{"title":"Study of Open Heavy-Flavour Hadron Production in pp and p–Pb Collisions with ALICE","authors":"P. Dhankher","doi":"10.1007/978-3-030-53448-6_39","DOIUrl":"https://doi.org/10.1007/978-3-030-53448-6_39","url":null,"abstract":"","PeriodicalId":8429,"journal":{"name":"arXiv: High Energy Physics - Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74036823","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-11-05DOI: 10.1007/978-3-030-53448-6_49
A. Tefelska
{"title":"$$K^{*}(892)^0$$ Production in p$$+$$p Interactions from NA61/SHINE","authors":"A. Tefelska","doi":"10.1007/978-3-030-53448-6_49","DOIUrl":"https://doi.org/10.1007/978-3-030-53448-6_49","url":null,"abstract":"","PeriodicalId":8429,"journal":{"name":"arXiv: High Energy Physics - Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80846078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-11-04DOI: 10.1142/9789811217739_0021
S. Olsen
The year 2019 marks the 30th anniversary of BES and the 100th anniversary of Rutherford's discovery of the proton. In spite of the fact that when BES operations started the proton was already 70 years old and the strange hyperons were all over 25, BES continues to make important and unique measurements of nucleon and hyperon properties, including some interesting discoveries.
{"title":"Nucleon/Hyperon Physics at BES","authors":"S. Olsen","doi":"10.1142/9789811217739_0021","DOIUrl":"https://doi.org/10.1142/9789811217739_0021","url":null,"abstract":"The year 2019 marks the 30th anniversary of BES and the 100th anniversary of Rutherford's discovery of the proton. In spite of the fact that when BES operations started the proton was already 70 years old and the strange hyperons were all over 25, BES continues to make important and unique measurements of nucleon and hyperon properties, including some interesting discoveries.","PeriodicalId":8429,"journal":{"name":"arXiv: High Energy Physics - Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85737059","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-10-31DOI: 10.1103/physrevc.102.014902
U. Acharya, A. Adare, C. Aidala, N. Ajitanand, Y. Akiba, M. Alfred, V. Andrieux, N. Apadula, H. Asano, B. Azmoun, V. Babintsev, M. Bai, N. Bandara, B. Bannier, K. Barish, S. Bathe, A. Bazilevsky, M. Beaumier, S. Beckman, R. Belmont, A. Berdnikov, Y. Berdnikov, D. Blau, M. Boer, J. Bok, K. Boyle, M. Brooks, J. Bryslawskyj, V. Bumazhnov, S. Campbell, V. C. Roman, R. Cervantes, C. Chen, C. Chi, M. Chiu, I. Choi, J. Choi, T. Chujo, Z. Citron, M. Connors, N. Cronin, M. Csanád, T. CsorgHo, T. Danley, A. Datta, M. Daugherity, G. David, K. DeBlasio, K. Dehmelt, A. Denisov, A. Deshpande, E. Desmond, A. Dion, P. B. Diss, D. Dixit, J. Do, A. Drees, K. Drees, J. Durham, A. Durum, A. Enokizono, H. En’yo, R. Esha, S. Esumi, B. Fadem, W. Fan, N. Feege, D. Fields, M. Finger, Jr., D. Fitzgerald, S. Fokin, J. Frantz, A. Franz, A. Frawley, Y. Fukuda, C. Gal, P. Gallus, E. Gamez, P. Garg, H. Ge, F. Giordano, A. Glenn, Y. Goto, N. Grau, S. Greene, M. Perdekamp, T. Gunji, H. Guragain, T. Hachiya, J. Haggerty, K. Hahn, H. Hamag
Charmonium is a valuable probe in heavy-ion collisions to study the properties of the quark gluon plasma, and is also an interesting probe in small collision systems to study cold nuclear matter effects, which are also present in large collision systems. With the recent observations of collective behavior of produced particles in small system collisions, measurements of the modification of charmonium in small systems have become increasingly relevant. We present the results of $J/psi$ measurements at forward and backward rapidity in various small collision systems, $p$$+$$p$, $p$$+$Al, $p$$+$Au and $^3$He$+$Au, at $sqrt{s_{_{NN}}}$=200 GeV. The results are presented in the form of the observable $R_{AB}$, the nuclear modification factor, a measure of the ratio of the $J/psi$ invariant yield compared to the scaled yield in $p$$+$$p$ collisions. We examine the rapidity, transverse momentum, and collision centrality dependence of nuclear effects on $J/psi$ production with different projectile sizes $p$ and $^3$He, and different target sizes Al and Au. The modification is found to be strongly dependent on the target size, but to be very similar for $p$$+$Au and $^{3}$He$+$Au. However, for 0%--20% central collisions at backward rapidity, the modification for $^{3}$He$+$Au is found to be smaller than that for $p$$+$Au, with a mean fit to the ratio of $0.89pm0.03$(stat)${pm}0.08$(syst), possibly indicating final state effects due to the larger projectile size.
Charmonium是重离子碰撞中研究夸克胶子等离子体性质的有价值的探针，也是小型碰撞系统中研究冷核物质效应的有趣探针，这种效应也存在于大型碰撞系统中。随着最近对小系统碰撞中产生的粒子的集体行为的观察，测量小系统中调和的修饰变得越来越重要。在$sqrt{s_{_{NN}}}$ =200 GeV的情况下，我们给出了$J/psi$在各种小型碰撞系统$p$$+$$p$、$p$$+$ Al、$p$$+$ Au和$^3$ He $+$ Au中向前和向后速度的测量结果。结果以可观测值$R_{AB}$的形式呈现，即核修饰因子，即$p$$+$$p$碰撞中$J/psi$不变产率与缩放产率之比的度量。我们研究了不同弹丸尺寸$p$和$^3$ He以及不同靶尺寸Al和Au的核效应对$J/psi$生产的快速性、横向动量和碰撞中心性的依赖。发现这种修饰强烈依赖于目标尺寸，但对于$p$$+$ Au和$^{3}$ He $+$ Au来说非常相似。然而，对于0%--20% central collisions at backward rapidity, the modification for $^{3}$He$+$Au is found to be smaller than that for $p$$+$Au, with a mean fit to the ratio of $0.89pm0.03$(stat)${pm}0.08$(syst), possibly indicating final state effects due to the larger projectile size.
{"title":"Measurement of \u0000J/ψ\u0000 at forward and backward rapidity in \u0000p+p\u0000, \u0000p+Al\u0000, \u0000p+Au\u0000, and \u0000He3+Au\u0000 collisions at \u0000sNN=200\u0000 GeV","authors":"U. Acharya, A. Adare, C. Aidala, N. Ajitanand, Y. Akiba, M. Alfred, V. Andrieux, N. Apadula, H. Asano, B. Azmoun, V. Babintsev, M. Bai, N. Bandara, B. Bannier, K. Barish, S. Bathe, A. Bazilevsky, M. Beaumier, S. Beckman, R. Belmont, A. Berdnikov, Y. Berdnikov, D. Blau, M. Boer, J. Bok, K. Boyle, M. Brooks, J. Bryslawskyj, V. Bumazhnov, S. Campbell, V. C. Roman, R. Cervantes, C. Chen, C. Chi, M. Chiu, I. Choi, J. Choi, T. Chujo, Z. Citron, M. Connors, N. Cronin, M. Csanád, T. CsorgHo, T. Danley, A. Datta, M. Daugherity, G. David, K. DeBlasio, K. Dehmelt, A. Denisov, A. Deshpande, E. Desmond, A. Dion, P. B. Diss, D. Dixit, J. Do, A. Drees, K. Drees, J. Durham, A. Durum, A. Enokizono, H. En’yo, R. Esha, S. Esumi, B. Fadem, W. Fan, N. Feege, D. Fields, M. Finger, Jr., D. Fitzgerald, S. Fokin, J. Frantz, A. Franz, A. Frawley, Y. Fukuda, C. Gal, P. Gallus, E. Gamez, P. Garg, H. Ge, F. Giordano, A. Glenn, Y. Goto, N. Grau, S. Greene, M. Perdekamp, T. Gunji, H. Guragain, T. Hachiya, J. Haggerty, K. Hahn, H. Hamag","doi":"10.1103/physrevc.102.014902","DOIUrl":"https://doi.org/10.1103/physrevc.102.014902","url":null,"abstract":"Charmonium is a valuable probe in heavy-ion collisions to study the properties of the quark gluon plasma, and is also an interesting probe in small collision systems to study cold nuclear matter effects, which are also present in large collision systems. With the recent observations of collective behavior of produced particles in small system collisions, measurements of the modification of charmonium in small systems have become increasingly relevant. We present the results of $J/psi$ measurements at forward and backward rapidity in various small collision systems, $p$$+$$p$, $p$$+$Al, $p$$+$Au and $^3$He$+$Au, at $sqrt{s_{_{NN}}}$=200 GeV. The results are presented in the form of the observable $R_{AB}$, the nuclear modification factor, a measure of the ratio of the $J/psi$ invariant yield compared to the scaled yield in $p$$+$$p$ collisions. We examine the rapidity, transverse momentum, and collision centrality dependence of nuclear effects on $J/psi$ production with different projectile sizes $p$ and $^3$He, and different target sizes Al and Au. The modification is found to be strongly dependent on the target size, but to be very similar for $p$$+$Au and $^{3}$He$+$Au. However, for 0%--20% central collisions at backward rapidity, the modification for $^{3}$He$+$Au is found to be smaller than that for $p$$+$Au, with a mean fit to the ratio of $0.89pm0.03$(stat)${pm}0.08$(syst), possibly indicating final state effects due to the larger projectile size.","PeriodicalId":8429,"journal":{"name":"arXiv: High Energy Physics - Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88272297","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
High-energy collisions in ALICE allow for the study of soft and hard QCD particle production. The correlation between transverse momentum spectra and event multiplicity is a sensitive observable providing insights into the different production mechanisms. In these proceedings we report on this observable for unidentified charged-particles, obtained using a 2d-unfolding procedure. Particle production is compared at different collision energies, as well as for pp, p--Pb and Pb--Pb collisions at the same energy. In order to understand the role of autocorrelations in small systems, it was proposed to exploit the usage of the underlying event as a multiplicity estimator to factorize the hardest and the softer components of the events. For this purpose, in these proceedings the charged particle transverse momentum distributions are also presented as a function of underlying-event activity in pp collisions.
{"title":"Particle production as a function of system size and underlying-event activity measured with ALICE at the LHC.","authors":"M. Krüger","doi":"10.22323/1.364.0493","DOIUrl":"https://doi.org/10.22323/1.364.0493","url":null,"abstract":"High-energy collisions in ALICE allow for the study of soft and hard QCD particle production. The correlation between transverse momentum spectra and event multiplicity is a sensitive observable providing insights into the different production mechanisms. In these proceedings we report on this observable for unidentified charged-particles, obtained using a 2d-unfolding procedure. Particle production is compared at different collision energies, as well as for pp, p--Pb and Pb--Pb collisions at the same energy. In order to understand the role of autocorrelations in small systems, it was proposed to exploit the usage of the underlying event as a multiplicity estimator to factorize the hardest and the softer components of the events. For this purpose, in these proceedings the charged particle transverse momentum distributions are also presented as a function of underlying-event activity in pp collisions.","PeriodicalId":8429,"journal":{"name":"arXiv: High Energy Physics - Experiment","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73560964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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