Measurement of the hard exclusive $π^{0}$ muoproduction cross section at COMPASS
Fuente:
arXiv
Saved in:
| Main Authors: | , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , |
|---|---|
| Format: | Preprint |
| Published: |
2024
|
| Subjects: | |
| Online Access: | |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866909445522456576 |
|---|---|
| author | Alexeev, G. D. Alexeev, M. G. Alice, C. Amoroso, A. Andrieux, V. Anosov, V. Augsten, K. Augustyniak, W. Azevedo, C. D. R. Badelek, B. Barth, J. Beck, R. Beckers, J. Bedfer, Y. Bernhard, J. Bodlak, M. Bradamante, F. Bressan, A. Chang, W. -C. Chatterjee, C. Chiosso, M. Chung, S. -U. Cicuttin, A. Correia, P. M. M. Crespo, M. L. D'Ago, D. Torre, S. Dalla Dasgupta, S. S. Dasgupta, S. Delcarro, F. Denisenko, I. Denisov, O. Yu. Dehpour, M. Donskov, S. V. Doshita, N. Dreisbach, Ch. Dünnweber, W. Dusaev, R. R. Ecker, D. Eremeev, D. Faccioli, P. Faessler, M. Finger, M. Finger Jr., M. Fischer, H. Flöthner, K. J. Florian, W. Friedrich, J. M. Frolov, V. Ordòñez, L. G. Garcia Gavrichtchouk, O. P. Gerassimov, S. Giarra, J. Giordano, D. Gorzellik, M. Grasso, A. Gridin, A. Perdekamp, M. Grosse Grube, B. Grüner, M. Guskov, A. Haas, P. von Harrach, D. Hoffmann, M. d'Hose, N. Hsieh, C. -Y. Ishimoto, S. Ivanov, A. Iwata, T. Jary, V. Joosten, R. Jörg, P. Kabuß, E. Kaspar, F. Kerbizi, A. Ketzer, B. Khaustov, G. V. Klein, F. Koivuniemi, J. H. Kolosov, V. N. Horikawa, K. Kondo Konorov, I. Korzenev, A. Yu. Kotzinian, A. M. Kouznetsov, O. M. Koval, A. Kral, Z. Kunne, F. Kurek, K. Kurjata, R. P. Lavickova, K. Levorato, S. Lian, Y. -S. Lichtenstadt, J. Lin, P. -J. Longo, R. Lyubovitskij, V. E. Maggiora, A. Makke, N. Mallot, G. K. Maltsev, A. Martin, A. Marzec, J. Matoušek, J. Matsuda, T. Pires, C. Menezes Metzger, F. Meyer, W. Mikhasenko, M. Mitrofanov, E. Miura, D. Miyachi, Y. Molina, R. Moretti, A. Nagaytsev, A. Neyret, D. Niemiec, M. Nový, J. Nowak, W. -D. Nukazuka, G. Olshevsky, A. G. Ostrick, M. Panzieri, D. Parsamyan, B. Paul, S. Pekeler, H. Peng, J. -C. Pešek, M. Peshekhonov, D. V. Pešková, M. Platchkov, S. Pochodzalla, J. Polyakov, V. A. Quintans, C. Reicherz, G. Riedl, C. Ryabchikov, D. I. Rychter, A. Rymbekova, A. Samoylenko, V. D. Sandacz, A. Sarkar, S. Savin, I. A. Sbrizzai, G. Schmieden, H. Selyunin, A. Sinha, L. Spülbeck, D. Srnka, A. Stolarski, M. Sulc, M. Suzuki, H. Tessaro, S. Tessarotto, F. Thiel, A. Tosello, F. Townsend, A. Triloki, T. Tskhay, V. Valinoti, B. Veit, B. M. Veloso, J. F. C. A. Ventura, B. Vidon, A. Vijayakumar, A. Virius, M. Wagner, M. Wallner, S. Zaremba, K. Zavertyaev, M. Zemko, M. Zemlyanichkina, E. Ziembicki, M. |
| author_facet | Alexeev, G. D. Alexeev, M. G. Alice, C. Amoroso, A. Andrieux, V. Anosov, V. Augsten, K. Augustyniak, W. Azevedo, C. D. R. Badelek, B. Barth, J. Beck, R. Beckers, J. Bedfer, Y. Bernhard, J. Bodlak, M. Bradamante, F. Bressan, A. Chang, W. -C. Chatterjee, C. Chiosso, M. Chung, S. -U. Cicuttin, A. Correia, P. M. M. Crespo, M. L. D'Ago, D. Torre, S. Dalla Dasgupta, S. S. Dasgupta, S. Delcarro, F. Denisenko, I. Denisov, O. Yu. Dehpour, M. Donskov, S. V. Doshita, N. Dreisbach, Ch. Dünnweber, W. Dusaev, R. R. Ecker, D. Eremeev, D. Faccioli, P. Faessler, M. Finger, M. Finger Jr., M. Fischer, H. Flöthner, K. J. Florian, W. Friedrich, J. M. Frolov, V. Ordòñez, L. G. Garcia Gavrichtchouk, O. P. Gerassimov, S. Giarra, J. Giordano, D. Gorzellik, M. Grasso, A. Gridin, A. Perdekamp, M. Grosse Grube, B. Grüner, M. Guskov, A. Haas, P. von Harrach, D. Hoffmann, M. d'Hose, N. Hsieh, C. -Y. Ishimoto, S. Ivanov, A. Iwata, T. Jary, V. Joosten, R. Jörg, P. Kabuß, E. Kaspar, F. Kerbizi, A. Ketzer, B. Khaustov, G. V. Klein, F. Koivuniemi, J. H. Kolosov, V. N. Horikawa, K. Kondo Konorov, I. Korzenev, A. Yu. Kotzinian, A. M. Kouznetsov, O. M. Koval, A. Kral, Z. Kunne, F. Kurek, K. Kurjata, R. P. Lavickova, K. Levorato, S. Lian, Y. -S. Lichtenstadt, J. Lin, P. -J. Longo, R. Lyubovitskij, V. E. Maggiora, A. Makke, N. Mallot, G. K. Maltsev, A. Martin, A. Marzec, J. Matoušek, J. Matsuda, T. Pires, C. Menezes Metzger, F. Meyer, W. Mikhasenko, M. Mitrofanov, E. Miura, D. Miyachi, Y. Molina, R. Moretti, A. Nagaytsev, A. Neyret, D. Niemiec, M. Nový, J. Nowak, W. -D. Nukazuka, G. Olshevsky, A. G. Ostrick, M. Panzieri, D. Parsamyan, B. Paul, S. Pekeler, H. Peng, J. -C. Pešek, M. Peshekhonov, D. V. Pešková, M. Platchkov, S. Pochodzalla, J. Polyakov, V. A. Quintans, C. Reicherz, G. Riedl, C. Ryabchikov, D. I. Rychter, A. Rymbekova, A. Samoylenko, V. D. Sandacz, A. Sarkar, S. Savin, I. A. Sbrizzai, G. Schmieden, H. Selyunin, A. Sinha, L. Spülbeck, D. Srnka, A. Stolarski, M. Sulc, M. Suzuki, H. Tessaro, S. Tessarotto, F. Thiel, A. Tosello, F. Townsend, A. Triloki, T. Tskhay, V. Valinoti, B. Veit, B. M. Veloso, J. F. C. A. Ventura, B. Vidon, A. Vijayakumar, A. Virius, M. Wagner, M. Wallner, S. Zaremba, K. Zavertyaev, M. Zemko, M. Zemlyanichkina, E. Ziembicki, M. |
| contents | 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 $Q^2$ ranging from 1 to 8 (GeV/$c$)$^{\rm\, 2}$ and the Bjorken variable $x_{\rm Bj}$ ranging from 0.02 to 0.45. The data were collected at COMPASS at CERN using 160 GeV/$c$ longitudinally polarised $μ^+$ and $μ^-$ beams scattering off a 2.5 m long liquid hydrogen target. From the average of the measured $μ^+$ and $μ^-$ cross sections, the virtual-photon--proton cross section is determined as a function of the squared four-momentum transfer between the initial and final state proton in the range 0.08 (GeV/$c$)$^{\rm\, 2}$ $< |t| <$ 0.64 (GeV/$c$)$^{\rm\, 2}$. From its angular distribution, the combined contribution of transversely and longitudinally polarised photons are determined, as well as transverse--transverse and longitudinal--transverse interference contributions. They are studied as functions of four-momentum transfer $|t|$, photon virtuality $Q^2$ and virtual-photon energy $ν$. The longitudinal--transverse interference contribution is found to be compatible with zero. The significant transverse--transverse interference contribution reveals the existence of a dominant contribution by transversely polarized photons. This provides clear experimental evidence for the chiral-odd GPD $\overline{E}_T$. In addition, the existence of a non-negligible contribution of longitudinally polarized photons is suggested by the $|t|$-dependence of the cross section at $x_{\rm Bj} < $ 0.1 . Altogether, these results provide valuable input for future modelling of GPDs and thus of cross sections for exclusive pseudo-scalar meson production. Furthermore, they can be expected to facilitate the study of next-to-leading order corrections and higher-twist contributions. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2412_19923 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Measurement of the hard exclusive $π^{0}$ muoproduction cross section at COMPASS Alexeev, G. D. Alexeev, M. G. Alice, C. Amoroso, A. Andrieux, V. Anosov, V. Augsten, K. Augustyniak, W. Azevedo, C. D. R. Badelek, B. Barth, J. Beck, R. Beckers, J. Bedfer, Y. Bernhard, J. Bodlak, M. Bradamante, F. Bressan, A. Chang, W. -C. Chatterjee, C. Chiosso, M. Chung, S. -U. Cicuttin, A. Correia, P. M. M. Crespo, M. L. D'Ago, D. Torre, S. Dalla Dasgupta, S. S. Dasgupta, S. Delcarro, F. Denisenko, I. Denisov, O. Yu. Dehpour, M. Donskov, S. V. Doshita, N. Dreisbach, Ch. Dünnweber, W. Dusaev, R. R. Ecker, D. Eremeev, D. Faccioli, P. Faessler, M. Finger, M. Finger Jr., M. Fischer, H. Flöthner, K. J. Florian, W. Friedrich, J. M. Frolov, V. Ordòñez, L. G. Garcia Gavrichtchouk, O. P. Gerassimov, S. Giarra, J. Giordano, D. Gorzellik, M. Grasso, A. Gridin, A. Perdekamp, M. Grosse Grube, B. Grüner, M. Guskov, A. Haas, P. von Harrach, D. Hoffmann, M. d'Hose, N. Hsieh, C. -Y. Ishimoto, S. Ivanov, A. Iwata, T. Jary, V. Joosten, R. Jörg, P. Kabuß, E. Kaspar, F. Kerbizi, A. Ketzer, B. Khaustov, G. V. Klein, F. Koivuniemi, J. H. Kolosov, V. N. Horikawa, K. Kondo Konorov, I. Korzenev, A. Yu. Kotzinian, A. M. Kouznetsov, O. M. Koval, A. Kral, Z. Kunne, F. Kurek, K. Kurjata, R. P. Lavickova, K. Levorato, S. Lian, Y. -S. Lichtenstadt, J. Lin, P. -J. Longo, R. Lyubovitskij, V. E. Maggiora, A. Makke, N. Mallot, G. K. Maltsev, A. Martin, A. Marzec, J. Matoušek, J. Matsuda, T. Pires, C. Menezes Metzger, F. Meyer, W. Mikhasenko, M. Mitrofanov, E. Miura, D. Miyachi, Y. Molina, R. Moretti, A. Nagaytsev, A. Neyret, D. Niemiec, M. Nový, J. Nowak, W. -D. Nukazuka, G. Olshevsky, A. G. Ostrick, M. Panzieri, D. Parsamyan, B. Paul, S. Pekeler, H. Peng, J. -C. Pešek, M. Peshekhonov, D. V. Pešková, M. Platchkov, S. Pochodzalla, J. Polyakov, V. A. Quintans, C. Reicherz, G. Riedl, C. Ryabchikov, D. I. Rychter, A. Rymbekova, A. Samoylenko, V. D. Sandacz, A. Sarkar, S. Savin, I. A. Sbrizzai, G. Schmieden, H. Selyunin, A. Sinha, L. Spülbeck, D. Srnka, A. Stolarski, M. Sulc, M. Suzuki, H. Tessaro, S. Tessarotto, F. Thiel, A. Tosello, F. Townsend, A. Triloki, T. Tskhay, V. Valinoti, B. Veit, B. M. Veloso, J. F. C. A. Ventura, B. Vidon, A. Vijayakumar, A. Virius, M. Wagner, M. Wallner, S. Zaremba, K. Zavertyaev, M. Zemko, M. Zemlyanichkina, E. Ziembicki, M. High Energy Physics - Experiment High Energy Physics - Phenomenology 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 $Q^2$ ranging from 1 to 8 (GeV/$c$)$^{\rm\, 2}$ and the Bjorken variable $x_{\rm Bj}$ ranging from 0.02 to 0.45. The data were collected at COMPASS at CERN using 160 GeV/$c$ longitudinally polarised $μ^+$ and $μ^-$ beams scattering off a 2.5 m long liquid hydrogen target. From the average of the measured $μ^+$ and $μ^-$ cross sections, the virtual-photon--proton cross section is determined as a function of the squared four-momentum transfer between the initial and final state proton in the range 0.08 (GeV/$c$)$^{\rm\, 2}$ $< |t| <$ 0.64 (GeV/$c$)$^{\rm\, 2}$. From its angular distribution, the combined contribution of transversely and longitudinally polarised photons are determined, as well as transverse--transverse and longitudinal--transverse interference contributions. They are studied as functions of four-momentum transfer $|t|$, photon virtuality $Q^2$ and virtual-photon energy $ν$. The longitudinal--transverse interference contribution is found to be compatible with zero. The significant transverse--transverse interference contribution reveals the existence of a dominant contribution by transversely polarized photons. This provides clear experimental evidence for the chiral-odd GPD $\overline{E}_T$. In addition, the existence of a non-negligible contribution of longitudinally polarized photons is suggested by the $|t|$-dependence of the cross section at $x_{\rm Bj} < $ 0.1 . Altogether, these results provide valuable input for future modelling of GPDs and thus of cross sections for exclusive pseudo-scalar meson production. Furthermore, they can be expected to facilitate the study of next-to-leading order corrections and higher-twist contributions. |
| title | Measurement of the hard exclusive $π^{0}$ muoproduction cross section at COMPASS |
| topic | High Energy Physics - Experiment High Energy Physics - Phenomenology |
| url | https://arxiv.org/abs/2412.19923 |