3D Structure of Nucleons and Nuclei, Como,June 12, 2013 INTERPLAY BETWEEN COLLINS ASYMMETRY AND...
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Transcript of 3D Structure of Nucleons and Nuclei, Como,June 12, 2013 INTERPLAY BETWEEN COLLINS ASYMMETRY AND...
![Page 1: 3D Structure of Nucleons and Nuclei, Como,June 12, 2013 INTERPLAY BETWEEN COLLINS ASYMMETRY AND TWO-HADRON ASYMMETRY F. Bradamante on behalf of the COMPASS.](https://reader038.fdocuments.us/reader038/viewer/2022103022/56649d095503460f949db551/html5/thumbnails/1.jpg)
3D Structure of Nucleons and Nuclei, Como,June 12, 2013
INTERPLAY BETWEEN
COLLINS ASYMMETRY AND
TWO-HADRON ASYMMETRY
F. Bradamante
on behalf of the COMPASS Collaboration
![Page 2: 3D Structure of Nucleons and Nuclei, Como,June 12, 2013 INTERPLAY BETWEEN COLLINS ASYMMETRY AND TWO-HADRON ASYMMETRY F. Bradamante on behalf of the COMPASS.](https://reader038.fdocuments.us/reader038/viewer/2022103022/56649d095503460f949db551/html5/thumbnails/2.jpg)
3D Structure of Nucleons and Nuclei, Como, June 12, 2013 Franco Bradamante
introduction
first attempt to quantify the “similarity” among Collins asymmetry for h+ and h- and hadron pair transverse spin asymmetry
hadron pairsreleased Aug. 2011
CollinsPLB 717 (2012) 376
![Page 3: 3D Structure of Nucleons and Nuclei, Como,June 12, 2013 INTERPLAY BETWEEN COLLINS ASYMMETRY AND TWO-HADRON ASYMMETRY F. Bradamante on behalf of the COMPASS.](https://reader038.fdocuments.us/reader038/viewer/2022103022/56649d095503460f949db551/html5/thumbnails/3.jpg)
3D Structure of Nucleons and Nuclei, Como,June 12, 2013 Franco Bradamante
introduction
first attempt to quantify the “similarity” among Collins asymmetry for h+ and h- and hadron pair transverse spin asymmetry
![Page 4: 3D Structure of Nucleons and Nuclei, Como,June 12, 2013 INTERPLAY BETWEEN COLLINS ASYMMETRY AND TWO-HADRON ASYMMETRY F. Bradamante on behalf of the COMPASS.](https://reader038.fdocuments.us/reader038/viewer/2022103022/56649d095503460f949db551/html5/thumbnails/4.jpg)
3D Structure of Nucleons and Nuclei, Como,June 12, 2013 Franco Bradamante
introduction
first attempt to quantify the “similarity” among Collins asymmetry for h+ and h- and hadron pair transverse spin asymmetry
preliminay results
two different approaches
1. Collins and 2h asymmetries from the same hadron sample information on the ratio of the analysing
powers kT x Collins FF vs IFF
2. correlations between the relevant azimuthal angles and corresponding asymmetries
information on the nature of the fragmentation
Collins vs 2h mechanisms
![Page 5: 3D Structure of Nucleons and Nuclei, Como,June 12, 2013 INTERPLAY BETWEEN COLLINS ASYMMETRY AND TWO-HADRON ASYMMETRY F. Bradamante on behalf of the COMPASS.](https://reader038.fdocuments.us/reader038/viewer/2022103022/56649d095503460f949db551/html5/thumbnails/5.jpg)
3D Structure of Nucleons and Nuclei, Como,June 12, 2013 Franco Bradamante
introduction
“standard” azimuthal angles
COMPASSPRL 94 (2005) 202002
COMPASSPLB 713 (2012) 10
![Page 6: 3D Structure of Nucleons and Nuclei, Como,June 12, 2013 INTERPLAY BETWEEN COLLINS ASYMMETRY AND TWO-HADRON ASYMMETRY F. Bradamante on behalf of the COMPASS.](https://reader038.fdocuments.us/reader038/viewer/2022103022/56649d095503460f949db551/html5/thumbnails/6.jpg)
3D Structure of Nucleons and Nuclei, Como,June 12, 2013 Franco Bradamante
introduction
correlations among the “standard” azimuthal angles
same with unpolarised Lepto
ϕh−❑
ϕh+¿❑¿
![Page 7: 3D Structure of Nucleons and Nuclei, Como,June 12, 2013 INTERPLAY BETWEEN COLLINS ASYMMETRY AND TWO-HADRON ASYMMETRY F. Bradamante on behalf of the COMPASS.](https://reader038.fdocuments.us/reader038/viewer/2022103022/56649d095503460f949db551/html5/thumbnails/7.jpg)
3D Structure of Nucleons and Nuclei, Como,June 12, 2013 Franco Bradamante
introduction
correlations among the “standard” azimuthal angles
same with unpolarised Lepto
ϕ𝑅❑
ϕh−❑
ϕh+¿❑¿
ϕh+¿❑¿
![Page 8: 3D Structure of Nucleons and Nuclei, Como,June 12, 2013 INTERPLAY BETWEEN COLLINS ASYMMETRY AND TWO-HADRON ASYMMETRY F. Bradamante on behalf of the COMPASS.](https://reader038.fdocuments.us/reader038/viewer/2022103022/56649d095503460f949db551/html5/thumbnails/8.jpg)
3D Structure of Nucleons and Nuclei, Como,June 12, 2013 Franco Bradamante
data samples and analysis
2010 data
same data selection and analysis than for published / released results
common hadron sample for Collins and 2h analysis, i.e.
• events which contain at least one positive hadron and at least one negative hadron
• for each event the number of hadrons is the number of h+h− pairs, as defined in the 2h analysis
• phT > 0.1 GeV/c and RT > 0.07 GeV/c
two sets of data, with zi > 0.1 and zi > 0.2
![Page 9: 3D Structure of Nucleons and Nuclei, Como,June 12, 2013 INTERPLAY BETWEEN COLLINS ASYMMETRY AND TWO-HADRON ASYMMETRY F. Bradamante on behalf of the COMPASS.](https://reader038.fdocuments.us/reader038/viewer/2022103022/56649d095503460f949db551/html5/thumbnails/9.jpg)
3D Structure of Nucleons and Nuclei, Como,June 12, 2013 Franco Bradamante
part 1 - results
zi > 0.2
![Page 10: 3D Structure of Nucleons and Nuclei, Como,June 12, 2013 INTERPLAY BETWEEN COLLINS ASYMMETRY AND TWO-HADRON ASYMMETRY F. Bradamante on behalf of the COMPASS.](https://reader038.fdocuments.us/reader038/viewer/2022103022/56649d095503460f949db551/html5/thumbnails/10.jpg)
3D Structure of Nucleons and Nuclei, Como,June 12, 2013 Franco Bradamante
part 1 - results
zi > 0.1
![Page 11: 3D Structure of Nucleons and Nuclei, Como,June 12, 2013 INTERPLAY BETWEEN COLLINS ASYMMETRY AND TWO-HADRON ASYMMETRY F. Bradamante on behalf of the COMPASS.](https://reader038.fdocuments.us/reader038/viewer/2022103022/56649d095503460f949db551/html5/thumbnails/11.jpg)
3D Structure of Nucleons and Nuclei, Como,June 12, 2013 Franco Bradamante
part 1 - results
zi > 0.1
in both cases, the 2h asymmetry is somewhat larger, as expected
from the ratio, information on the relative strength of the analysisng powers
![Page 12: 3D Structure of Nucleons and Nuclei, Como,June 12, 2013 INTERPLAY BETWEEN COLLINS ASYMMETRY AND TWO-HADRON ASYMMETRY F. Bradamante on behalf of the COMPASS.](https://reader038.fdocuments.us/reader038/viewer/2022103022/56649d095503460f949db551/html5/thumbnails/12.jpg)
3D Structure of Nucleons and Nuclei, Como,June 12, 2013 Franco Bradamante
part 2
a different definition of the 2h azimuthal angle
very simple
![Page 13: 3D Structure of Nucleons and Nuclei, Como,June 12, 2013 INTERPLAY BETWEEN COLLINS ASYMMETRY AND TWO-HADRON ASYMMETRY F. Bradamante on behalf of the COMPASS.](https://reader038.fdocuments.us/reader038/viewer/2022103022/56649d095503460f949db551/html5/thumbnails/13.jpg)
3D Structure of Nucleons and Nuclei, Como,June 12, 2013 Franco Bradamante
part 2 – correlation between ϕR’ and ϕR
with unpolarised Lepto
same result,
even using vectors and not unit vectors
ϕ𝑅❑
ϕ𝑅 ′❑
![Page 14: 3D Structure of Nucleons and Nuclei, Como,June 12, 2013 INTERPLAY BETWEEN COLLINS ASYMMETRY AND TWO-HADRON ASYMMETRY F. Bradamante on behalf of the COMPASS.](https://reader038.fdocuments.us/reader038/viewer/2022103022/56649d095503460f949db551/html5/thumbnails/14.jpg)
3D Structure of Nucleons and Nuclei, Como,June 12, 2013 Franco Bradamante
part 2 – 2h asymmetries using ϕR’ and ϕR
zi > 0.2
2h asymmetries using ϕR’ and ϕR
![Page 15: 3D Structure of Nucleons and Nuclei, Como,June 12, 2013 INTERPLAY BETWEEN COLLINS ASYMMETRY AND TWO-HADRON ASYMMETRY F. Bradamante on behalf of the COMPASS.](https://reader038.fdocuments.us/reader038/viewer/2022103022/56649d095503460f949db551/html5/thumbnails/15.jpg)
3D Structure of Nucleons and Nuclei, Como,June 12, 2013 Franco Bradamante
part 2 – 2h asymmetries using ϕR’ and ϕR
zi > 0.1
2h asymmetries using ϕR’ and ϕR
![Page 16: 3D Structure of Nucleons and Nuclei, Como,June 12, 2013 INTERPLAY BETWEEN COLLINS ASYMMETRY AND TWO-HADRON ASYMMETRY F. Bradamante on behalf of the COMPASS.](https://reader038.fdocuments.us/reader038/viewer/2022103022/56649d095503460f949db551/html5/thumbnails/16.jpg)
3D Structure of Nucleons and Nuclei, Como,June 12, 2013 Franco Bradamante
summary
the asymmetries are very close, hinting at a common physical origin for the Collins mechanism and the di-hadron fragmentation function …