Chun-Wang Ma( 马春旺 ) Henan Normal University 河南师范大学 （

1. Motivation 2. Methods 3. Results  3.1 Results-measured results by NIMROD  3.2 Results-simulated reactions by AMD 4. Summary Outline Dec 15,

Temperature:  One of the important questions in heavy-ion collisions. Colliding system start from a violent collision, in which the matter is compressed, and the temperature increases fast and may reaches the critical point that the liquid-gas transition happens. The compressed matter expands and the temperature decreases. At the time of chemical freeze-out, the fragments are finally formed. 1. Motivation Dec 15,

1. Motivation Dec 15, 压缩 膨胀 碎片生成 次级衰变 time evolution of heavy-ion collisions time evolution of temperature (time converted from v surf ) Wang et al., PRC72, supra-saturation density

Methods to probe the temperature  Albergo isotopic temperature (light particles, IMFs)  slope temperature (from the kinetic energy spectra of light particles)  momentum fluctuation  thermal energy  excitation energy  self-consistent fitting method for primary IMF  isobaric ratio and improved isobaric ratio methods  etc. Temperature influences the results of other important physical parameters, such as the nuclear symmetry energy 1. Motivation Dec 15,

in isoscaling, the isoscaling paramters depend on temperature, In experiments, the temperature depends on the violence of the colliding. In simple word, the central/semi-central/semi- peripheral/peripheral collisions, the temperatures for fragments are different. In other similar methods as isoscaling, which use the fragment ratio, temperature also influence the results definitely. 1. Motivation Dec 15,

In this report, we study the temperature change in the different colliding areas,  central collisions,  semi-central collisions,  semi-peripheral collisions,  and peripheral collisions. Reactions will be investigated:  Measured by Prof. Natowitz's group at TAMU  Simulated reactions using the AMD model 1. Motivation Dec 15,

Thermometer will be used:  Albergo isotopic ratio method Usually, isotopic ratios of light particles are used  p,d,T, He, Li, etc. fragment having large atomic number also been adopted  Be, B, and C isotopes, and heavier fragments The temperature from the light particles and IMFs are different 2. Method Dec 15, Refs: S. Albergo et al., Nuovo Cimento A 89, 1 (1985); J. B. Natowitz et al., Phys. Rev. C 52, R2322 (1995); Y. G. Ma et al., Phys. Rev. C 71, (2005); J. Pochodzalla et al., Phys. Rev. Lett. 75, 1040 (1995).Nuovo Cimento A 89, 1 (1985)Phys. Rev. C 52, R2322 (1995)Phys. Rev. C 71, (2005)J. Pochodzalla et al., Phys. Rev. Lett. 75, 1040 (1995) isotopic method for IMFs: H. F. Xi et al., Phys. Rev. C 58, R2636 (1998); W. Trautmann et al., Phys. Rev. C 76, (2007).C. W. Ma et al., CTP59, 95 (2013).Phys. Rev. C 58, R2636 (1998)Phys. Rev. C 76, (2007)CTP59, 95 (2013)

The typical formula to calculate the temperature using isotopic raitos T HeLi is frequently used 2. Method Dec 15, W. Trautmann et al., Phys. Rev. C 76, (2007)Phys. Rev. C 76, (2007)

2. Method Dec 15, W. Trautmann et al., Phys. Rev. C 76, (2007)Phys. Rev. C 76, (2007) Temperatures are different for fragments  (Left) Z bound for spectator decays at 600 and 1000 MeV/u Au+Au.  (Right) central collisions at 50 and 200MeV/u as function of incident energy.  There is a evolution of temperature as the impact parameter. a plateau for IMF

Temperature dependence on colliding areas:  The 26, 35, 47 MeV/u Zn + Au/Mo/Ni reactions measured by NIMROD at TAMU. T HHe adopted. Systematic dependence on reaction system and velocity will be investigated.  The 140 MeV/u 58,64 Ni + 9 Be reactions simulated using the AMD model (primary fragments). light particles and IMFs adopted for the Albergo isotopic thermometers.  Fragments are grouped according to the colliding violence or impact parameters. 2. Method Dec 15,

Temperature obtained from the isotopic ratios  the measured light particles in the 47, 35, and 26 MeV/u Zn + Au/Mo/Ni reactions by NIMROD at TAMU by Prof. Natowitz's group T HHe used light particle grouped according to the colliding violence  the simulated 140MeV/u Ni+Be reactions using the AMD model T HHe and more isotopic ratio temperature obtained particles grouped according to the impact parameters 3. Results Dec 15,

NIMROD-- a 4π detector for light particles and IMFs Different rings according to different angles 47, 35, 26 MeV/u Zn+Au/Mo/Ni reactions measured Light particles and fragments identified 3.1 Results--measured by NIMROD Dec 15,

3.1 Results--measured by NIMROD Dec 15, R Vsurf = Y d Y 4He /Y t Y 3He Central collisions 47 MeV/u Zn+X T depends on V surf (or time) Reaction system Angles (reaction areas) Preliminary

Dec 15, Results--measured by NIMROD Central collisions 26 MeV/u Zn+X Similar results found as in the 47MeV/u reactions But The dependences are weakened Preliminary

Same reactions but at different incident energies Dec 15, Results--measured by NIMROD Central collisions Preliminary

Comparison between different rings Temperatures at different ring (angle ) are different, and depend on V surf. Dec 15, Results--measured by NIMROD Central collisions Preliminary

Comparison between different rings At 26MeV/u Dec 15, Results--measured by NIMROD Central collisions Preliminary

3.1 Results--measured by NIMROD Dec 15, MeV/u Zn+X peripheral collisions similar results in different rings (angle) Preliminary

Dec 15, Results--measured by NIMROD A comparison between different reaction areas. 47MeV/u B1: peripheral B2: semi- peripheral B3: semi-central B4: central An increase of temperature is found from b1 to b4, especially in the foward rings. Preliminary

3.1 Results--measured by NIMROD Dec 15, A comparison between different reaction areas. 26MeV/u B1: peripheral B2: semi- peripheral B3: semi- central B4: central An increase of temperature from B1 to B4. Preliminary

Various dependences of T have been found in the measured data by NIMROD. It is interesting to see theoretically the T obtained from the other isotopic ratios, and the T dependence on impact parameter. A simulation using the AMD model has been performed for the 140 MeV/u Ni+Be reactions. 3.1 conclusion Dec 15,

3.2 Results--simulated by AMD Dec 15, AMD-V simulation 140 MeV/u 58,64 Ni + 9 Be reactions  Standard Gogny (g0) interaction (soft)  fragment recoganization Time evolution: Colliding times at t= 20, 40, 60, 80, 100, 120, 140, 180, 200, 250, 300, 500, 700, 1000 fm/c From central to peripheral collisions: Different impact parameter ranges: b=0-2, 0-4, 0-6, 0-9 fm. Coalescence algorithm with R c =2.5 fm. M. Mocko et al., PRC 74, (2006).PRC 74, (2006) Some related results for the simulated reactions: Ma et al., PRC 87, (2013);PRC 87, (2013) Qiao et al., PRC 92, (2015);PRC 92, (2015) Ma et al., CPL 32, (2015).CPL 32, (2015)

temperature calculated from the following isotopic ratios, 3.2 Results--simulated by AMD Dec 15, heavier isotopes used

Peaks found for different isotopic temperature but at different times. impact parameters affect the temperature for light particles. temperature less influenced for heavier isotopes. Data analysis is still in progess. 3.2 Results--simulated by AMD Dec 15, Preliminary

The Albergo isotopic thermometers have been used to study the temperature in heavy-ion collisions. For the measured reactions by NIMROD, the temperature is obtained by T HHe. For the simulated reactions, temperature is also found depend on the impact parameter, and the results depend on the isotopic ratios used. Analysis still in progess. Dec 15, Summary

The experimental data were analyzed during my visiting to TAMU. Thanks to Joe, Roy, Kris, Sara, Marina, Xiguang, and Meirong for their support and help in my the data analysis and during my stay at TAMU. Thanks Meirong and Roy for the help in the simulation using the AMD model. Thank you for attention! Comments are welcomed! Dec 15, Thanks to…