You said,
I would like to make a reference request for articles, papers or monographs that address the question of what is the experience of physical pain during self-harm
I would first like to point out that while you will find that lists of references indicate many articles are in suicide journals and books on suicide, self-harm — sometimes referred to as non-suicidal self-injury (NSSI) — is not strictly part of suicide ideation and behaviour.
Psychological research into suicide behaviour and ideation has led to the development of the Cry of Pain (CoP) model, an entrapment model of suicidality. As Rasmussen et al. (2010) points out, the CoP model
suggests that suicidal ideation and behaviour are the end products of a perception of being trapped in a
stressful situation from which there is no escape and no rescue.
Looking at the Cry of Pain (CoP) model of suicide (Williams, 2001), the CoP model and Williams & Pollock (2000; 2001) suggest that suicidal behaviour (whether the outcome is life or death) should be seen as a “cry of pain” rather than the traditional “cry for help”. However, Scoliers, et al. (2009) found that adolescents who deliberately self-harm often report both CoP and cry for help motives.
Systematic reviews (scoping, rapid, and narrative reviews, mixed method/mixed studies, and meta-analyses) tend to be great sources for more material to read after reading them.
A systematic review of studies (Kirtley, et al. 2016) found,
The evidence suggests that there is elevated pain tolerance among those who engage in NSSI. Future prospective research should determine if altered pain tolerance is a cause or a consequence of the behaviour. The identification of psychological correlates of increased pain tolerance is a neglected area of research. It could provide opportunities for treatment/intervention development, if mediating or moderating pathways can be identified. Too few studies have directly investigated candidate explanatory mechanisms to draw definitive conclusions.
A later systematic review (Brereton & McGlinchey, 2020) found that,
Results tentatively support the role of experiential avoidance in self-harm; some studies described phenomena similar to experiential avoidance without using the term. Poor emotion regulation was often cited as a reason for engagement in self-harm. Several gaps in the literature were identified and discussed.
References
Brereton, A., & McGlinchey, E. (2020). Self-harm, emotion regulation, and experiential avoidance: A systematic review. Archives of suicide research, 24(sup1), 1-24. https://doi.org/10.1080/13811118.2018.1563575
Kirtley, O. J., O’Carroll, R. E., & O’Connor, R. C. (2016). Pain and self-harm: A systematic review. Journal of affective disorders, 203, 347-363. https://doi.org/10.1016/j.jad.2016.05.068
Rasmussen, S. A., Fraser, L., Gotz, M., MacHale, S., Mackie, R., Masterton, G., ... & O'Connor, R. C. (2010). Elaborating the cry of pain model of suicidality: Testing a psychological model in a sample of first‐time and repeat self‐harm patients. British Journal of Clinical Psychology, 49(1), 15-30. https://doi.org/10.1348/014466509X415735
Scoliers, G., Portzky, G., Madge, N., Hewitt, A., Hawton, K., De Wilde, E. J., ... & Van Heeringen, K. (2009). Reasons for adolescent deliberate self-harm: a cry of pain and/or a cry for help?. Social psychiatry and psychiatric epidemiology, 44(8), 601-607. https://doi.org/10.1007/s00127-008-0469-z
Williams, J. M. G. (2001). The Cry of Pain. London: Penguin.
Williams, J.M.G. & Pollock, L.R. (2000). The psychology of suicidal behaviour. In K. Hawton & K. van Heeringen (Eds.), The international handbook of suicide and attempted suicide (pp. 79-93). Chichester: John Wiley & Sons.
Williams, J.M.G. & Pollock, L.R. (2001). Psychological aspects of the suicidal
process. In K. van Heeringen (Ed.), Understanding suicidal behaviour (pp. 76-
93). Chichester: John Wiley & Sons.